Biomedical subjects

T Hashimoto

Publications and source records attributed to T Hashimoto.

At least 235 records · Page 13Linked to original sources

PubMed2001

Usefulness of long axis M-mode echocardiographic measurements for optimum dialysis in patients on maintenance hemodialysis: comparison with changes in plasma levels of atrial natriuretic peptide and brain natriuretic peptide.

UNLABELLED: It has been suggested that analyzing the left ventricular long axis motion can result in the sensitive detection of cardiac functional disorders. AIM: To evaluate the usefulness of left ventricular long axis indices in managing patients on maintenance hemodialysis. METHODS: Eighteen hemodialysis patients (mean age 51 +/- 10 years) as well as 16 healthy persons (mean age 49 +/- 9 years) were examined. Echocardiograms were recorded, and the plasma concentrations of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) were measured before and after a session of hemodialysis. The following parameters were measured: the left atrial diameter (LAD) and end-diastolic left ventricular diameter (LVDd) from M-mode echocardiograms, the end-diastolic LV volume (LVEDV) and ejection fraction (EF) from 2-D echocardiography, the E/A ratio from transmitral Doppler, the atrial systolic excursion of long axis motion of the mitral ring (ALAM) and maximal lengthening rate of the mitral ring toward the left atrium during the early diastolic phase (MLRe) from LV long axis M-mode echocardiograms. RESULTS: LAD, LVDd, LVEDV, and ALAM showed a positive correlation with plasma levels of ANP and BNP. EF, the E/A ratio, and MLRe showed a negative correlation with plasma levels of ANP and BNP. Changes in ALAM and plasma levels of ANP during hemodialysis were larger in the subgroup of ALAM < or = 0.55 cm before hemodialysis than in the subgroup of ALAM < 0.55 cm before hemodialysis. CONCLUSION: These results indicate that the left ventricular long axis index can detect a disorder of left ventricular diastolic function, and that a hemodialysis patient whose ALAM before hemodialysis is < 0.55 cm is dialyzed with good volume control conditions.

Adult↗

PubMed2001

[A case of spontaneous rupture of a suprasellar cystic mass].

The author reported a case of a spontaneous rupture of a suprasellar cystic tumor. A 67-year-old man complained of bitemporal homonymous hemianopsia. His visual acuity was 0.02 on the right side and 0.04 on the left side. Skull XP revealed no abnormal findings, but brain CT scan showed a cystic mass without calcification in the suprasellar region. Brain MRI at the same lesion site depicted a low-intensity mass on T1-weighted image without gadolinium enhancement, and a high-intensity mass on T2-weighted image. The patient was treated conservatively because of complications such as diabetes mellitus, cerebral infarction and old myocardiac infarction. MRI taken 5 years after the initial MRI revealed disappearance of the suprasellar cystic mass. However, the patient's neurological findings, including visual signs, revealed no deterioration. His physical and radiological findings had remained uneventful. In this report, we reviewed the literatures about spontaneous rupture of suprasellar cystic tumors. It was considered that in this case, according to the neurological, radiological and CSF findings, the suprasellar cystic mass might be a Rathke's cleft cyst or arachnoid cyst.

Adenoma↗

PubMed2001

[Reconstruction of the cervical esophagus by interposition of the transverse colon].

Currently, the first choice viscus for reconstruction after total pharyngolaryngoesophagectomy is a jejunal interposition. This requires at least one end-to-side anastomosis in the pharyngo-jejunal anastomosis, esophago-jejunal anastomosis, or both due to the small diameter of the jejunum and round shape of the mesenterium. Furthermore, the jejunal graft experiences a spasm when the patient swallows. For such reasons the jejunal free graft is not suitable for swallowing. On the other hand, the transverse colon graft is more appropriate for reconstruction for the following reasons: it has a straight shape; end-to-end anastomosis is possible to both the pharynx and esophagus; and there are postoperative complications due to simple anastomosis of the remaining colon after graft removal. Blood vessel anastomoses, performed using microsurgery techniques, are followed by esophageal reconstructive anastomoses. Fifteen patients successfully underwent this type of reconstruction in our institution.

Aged↗

PubMed2001

[An unconscious patients with ascending aortic aneurysm accompanied by aortic regurgitation successfully treated by emergency operation after cardiopulmonary resuscitation].

A-37-year-old woman in shock condition was transferred to our hospital after cardiopulmonary resuscitation for ventricular fibrillation. She was unconscious and suspected of suffering ischemic brain damage, with pathologic reflexes and weak brain stem reflexes. Brain CT scan showed cerebral edema without hemorrhage or infarction and an electroencephalograph revealed slow alpha-theta waves. Chest CT scan and echocardiogram showed ascending aortic aneurysm with sever aortic regurgitation. An emergent operation was performed for progression of heart failure. There were no distortion or dilatation of the sinus of Valsalva and annuloaortic ectasia and aortic valve leaflets were almost normal. We considered that the aortic valve dysfunction was cause by dilatation of the sinotubular junction. Ascending aortic and aortic valve replacement were carried out to shorten cardiopulmonary bypass time and to prevent the progression of brain damage. Mild hypothermia was employed as a neuroprotective procedure for three days after surgery. The patient's neurological symptoms, which were right hemiparesis, facial apraxia and motor aphasia, improved and she was discharged from the hospital on foot without any neurological complications on the 47th postoperative day and returned to work after two months.

Adult↗

PubMed2001

Paroxysmal discharges on EEG in young autistic patients are frequent in frontal regions.

EEGs were recorded in 86 autistic patients during sleep. Epileptic discharges were observed in 37 cases (43%). Twenty-seven (73%) of these 37 cases had localized spikes, 8 had multiple spike foci, one had generalized spikes, and one had both multiple spike foci and generalized spikes. Forty-seven epileptic discharge foci were registered in 36 cases, the exception being one with generalized spikes. Thirty-six (76.6%) of the registered 47 epileptic discharge foci were in the frontal region, one (2.1%) in the temporal region, 7 (14.1%) in the centro-parietal region, and 3 (6.4%) in the occipital region. Twenty (55.6%) of the 36 frontal spikes were at midline (11 at Fz and 9 at Cz), 8 on the left side, and 8 on the right side. The dipole of midline spikes was in the deep midline frontal region. These results suggest that frontal dysfunctions are important in the mechanism of symptoms in autism.

Adolescent↗

PubMed2001

Constitutive activity of histamine h(3) receptors stably expressed in SK-N-MC cells: display of agonism and inverse agonism by H(3) antagonists.

Agonist-independent activity of G-protein-coupled receptor, also referred to as constitutive activity, is a well-documented phenomenon and has been reported recently for both the histamine H(1) and H(2) receptors. Using SK-N-MC cell lines stably expressing the human and rat H(3) receptors at physiological receptor densities (500-600 fmol/mg of protein), we show that both the rat and human H(3) receptors show a high degree of constitutive activity. The forskolin-mediated cAMP production in SK-N-MC cells is inhibited strongly upon expression of the G(i)-coupled H(3) receptor. The cAMP production can be further inhibited upon agonist stimulation of the H(3) receptor and can be enhanced by a variety of H(3) antagonists acting as inverse agonists at the H(3) receptor. Thioperamide, clobenpropit, and iodophenpropit raise the cAMP levels in SK-N-MC cells with potencies that match their receptor binding affinities. Surprisingly, impentamine and burimamide act as effective H(3) agonists. Modification of the amine group of impentamine dramatically affected the pharmacological activity of the ligand. Receptor affinity was reduced slightly for most impentamine analogs, but the functional activity of the ligands varied from agonist to neutral antagonist and inverse agonist, indicating that subtle changes in the chemical structures of impentamine analogs have major impact on the (de)activation steps of the H(3) receptor. In conclusion, upon stable expression of the rat and human H(3) receptor in SK-N-MC cells constitutive receptor activity is detected. In this experimental system, H(3) receptors ligands, previously identified as H(3) antagonists, cover the whole spectrum of pharmacological activities, ranging from full inverse agonists to agonists.

Animals↗

PubMed2001

[Relationship between skipping breakfast and cardiovascular disease risk factors in the national nutrition survey data].

PURPOSE: To investigate the relationship between skipping breakfast and cardiovascular disease risk factors such as blood pressure, serum lipids, smoking, and lock of exercise. MATERIALS AND METHODS: Data from the National Nutrition survey conducted by the Ministry of Health and Welfare, from 1995 through 1997 were employed for the analysis. Data were used only if subjects were between 20 and 59 years old and had participated in the nutrition survey, and values for height and weight, blood pressure, serum lipids, blood sugar, number of steps per day, and smoking, drinking, and exercise habits were available. The number of subjects with data available for all of the above was 11,778 (4,438 men and 7,340 women). Analyses were performed separately by sex. The relationship between skipping breakfast and continuous variables such as nutrient intake ratio (nutrient intake divided by recommended dietary allowances), body mass index, blood pressure, serum lipids, blood sugar, and the number of steps per day was examined controlling for age using analysis of covariance (ANCOVA). The relationship between skipping breakfast and categorical variables such as smoking, drinking, and exercise habits was assessed controlling for age using Cochran-Mantel-Haenszel statistics. RESULTS: The younger the generation, the higher the rate of skipping breakfast. The rate of skipping breakfast in men was twice as high as in women. The breakfast skippers tended to intake less energy and calcium, both in men and women, that non-skippers. Female skippers tended to intake less iron and vitamin D. The number of steps per day was smaller in breakfast skippers than that in non-skippers both in men and women. Male skippers tended to have higher blood pressure than non-skippers, and female skippers tended to have a higher serum total cholesterol level than non-skippers. The breakfast skippers tended to smoke more than non-skippers, both in men and women, and female skippers tended to drink more alcohol and take less exercise. CONCLUSIONS: Skipping breakfast is related to cardiovascular risk factors such as lack of exercise, smoking, high blood pressure, and high serum total cholesterol.

Adult↗

PubMed2001

[A case of sinus pericranii manifesting as a parietal midline mass].

A case of sinus pericranii was reported. A 5-year-old boy was admitted to our hospital, complaining of scalp mass located at the midparietal region. He was noticed to have had it since 3 years before. The mass decreased in size under mild compression, and during standing position, but increased in size due to lying down. Magnetic resonance imaging (MRI) demonstrated a mass with mixed signal intensity on the T1 weighted image and high signal intensity on the T2 weighted image. Gd-DTPA study showed irregular enhancement. Cerebral angiogram showed no communication between the mass and the superior sagittal sinus. Neither did direct injection of contrast medium into the mass revealed any communication. 3D-CT demonstrated three tiny bone defects beneath the mass. Open surgery revealed that the mass existed between the galea aponeurotica and the periosteum, which had a small communication with the emissary vein. Pathological examination showed a multiple lobular cyst with endothelial wall lining. This case report highlighted the fact that sinus pericranii with minimal communication with the dural sinus can be treated by removal of the mass and closure of the cranial bone abnormalities with bone wax without craniotomy.

Cerebral Angiography↗

PubMed2001

[A case of metastatic breast cancer showing extraosseous accumulation of 99mTc-HMDP in axillary lymph nodes on bone scintigraphy].

We report a case of metastatic breast cancer that showed extraosseous accumulation of 99mTc-HMDP in left axillary lymph nodes on bone scintigraphy. Our patient had a giant left breast mass and multiple lymph node metastases with atypical calcifications. It is known that breast cancer sometimes is positively visualized as extraosseous accumulation on bone scintigraphy. Accumulation to metastatic lymph nodes of breast cancer has rarely been reported. It is suggested that bone scintigraphy is of benefit in detecting the metastatic lymph nodes of breast cancer as a screening or follow-up method.

Axilla↗

PubMed2001

[Clinical application of metabolic bone markers in hematologic malignancies].

Hematologic malignancies such as multiple myeloma, adult T cell leukemia and malignant lymphoma are often complicated with bone lesions and/or hypercalcemia. The abnormal bone metabolism in these diseases are modified by co-existing cachexia, malnutrition, sex hormone deficiency and abnormal parathyroid function or by chemotherapy in a complex manner. Metabolic bone markers are not only clinically useful for evaluation and diagnosis of such bone abnormalities but may also be used to monitor the disease activity itself, particularly in multiple myeloma which almost inevitably involves bone destructive lesions.

English Abstract↗

PubMed2000

3-Amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) induces apoptosis in rat splenocytes and thymocytes by different mechanisms.

3-Amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) is a potent carcinogen present in cooked meat. Although the target of this carcinogen is mainly in the liver, Trp-P-1 is distributed in the thymus and spleen as well as in the liver after administration. However, the cytotoxic effect of Trp-P-1 on lymphocytes has not been examined in detail. In the present study, we investigated the cytotoxicity of Trp-P-1 against rat splenocytes and thymocytes. Trp-P-1 reduced viability of both types of cells in the same manner, the LD(50) at 6h in culture was 15 microM, and the time for the 50% decrease in cell viability (t(1/2)) at 20 microM was 3h. In both types of cells, Trp-P-1 caused the activation of caspase-3-like proteases and the cleavage of poly(ADP-ribose) polymerase, both of which are biochemical markers of apoptosis. On the other hand, DNA fragmentation occurred in splenocytes, but not in thymocytes although Trp-P-1 activated 32-34kDa nucleases that may not be able to degrade DNA into nucleosomal units. These results indicated that Trp-P-1 induces apoptosis in both splenocytes and thymocytes by different mechanisms in which distinct apoptotic pathways may exist downstream of the caspase cascade.

Animals↗

PubMed2000

Antinociceptive action of nitrous oxide is mediated by stimulation of noradrenergic neurons in the brainstem and activation of [alpha]2B adrenoceptors.

Although nitrous oxide (N(2)O) has been used to facilitate surgery for >150 years, its molecular mechanism of action is not yet defined. Having established that N(2)O-induced release of norepinephrine mediates the analgesic action at alpha(2) adrenoceptors in the spinal cord, we now investigated whether activation of noradrenergic nuclei in the brainstem is responsible for this analgesic action and which alpha(2) adrenoceptor subtype mediates this property. In rats, Fos immunoreactivity was examined in brainstem noradrenergic nuclei after exposure to nitrous oxide. After selective lesioning of noradrenergic nuclei by intracerebroventricular application of the mitochondrial toxin saporin, coupled to the antibody directed against dopamine beta hydroxylase (DbetaH-saporin), the analgesic and sedative actions of N(2)O were determined. Null mice for each of the three alpha(2) adrenoceptor subtypes (alpha(2A), alpha(2B), and alpha(2C)), and their wild-type cohorts, were tested for their antinociceptive and sedative response to N(2)O. Exposure to N(2)O increased expression of Fos immunoreactivity in each of the pontine noradrenergic nuclei (A5, locus coeruleus, and A7). DbetaH-saporin treatment eliminated nearly all of the catecholamine-containing neurons in the pons and blocked the analgesic but not the sedative effects of N(2)O. Null mice for the alpha(2B) adrenoceptor subtype exhibited a reduced or absent analgesic response to N(2)O, but their sedative response to N(2)O was intact. Our results support a pivotal role for noradrenergic pontine nuclei and alpha(2B) adrenoceptors in the analgesic, but not the sedative effects of N(2)O. Previously we demonstrated that the analgesic actions of alpha(2) adrenoceptor agonists are mediated by the alpha(2A) subtype; taken together with these data we propose that exogenous and endogenous alpha(2) adrenoceptor ligands activate different alpha(2) adrenoceptor subtypes to produce their analgesic action.

Analgesics↗

PubMed2000

Phosphorylation of tau is regulated by PKN.

For the phosphorylation state of microtubule-associated protein, tau plays a pivotal role in regulating microtubule networks in neurons. Tau promotes the assembly and stabilization of microtubules. The potential for tau to bind to microtubules is down-regulated after local phosphorylation. When we investigated the effects of PKN activation on tau phosphorylation, we found that PKN triggers disruption of the microtubule array both in vitro and in vivo and predominantly phosphorylates tau in microtubule binding domains (MBDs). PKN has a catalytic domain highly homologous to protein kinase C (PKC), a kinase that phosphorylates Ser-313 (= Ser-324, the number used in this study) in MBDs. Thus, we identified the phosphorylation sites of PKN and PKC subtypes (PKC-alpha, -betaI, -betaII, -gamma, -delta, -epsilon, -zeta, and -lambda) in MBDs. PKN phosphorylates Ser-258, Ser-320, and Ser-352, although all PKC subtypes phosphorylate Ser-258, Ser-293, Ser-324, and Ser-352. There is a PKN-specific phosphorylation site, Ser-320, in MBDs. HIA3, a novel phosphorylation-dependent antibody recognizing phosphorylated tau at Ser-320, showed immunoreactivity in Chinese hamster ovary cells expressing tau and the active form of PKN, but not in Chinese hamster ovary cells expressing tau and the inactive form of PKN. The immunoreactivity for phosphorylated tau at Ser-320 increased in the presence of a phosphatase inhibitor, FK506 treatment, which means that calcineurin (protein phosphatase 2B) may be involved in dephosphorylating tau at Ser-320 site. We also noted that PKN reduces the phosphorylation recognized by the phosphorylation-dependent antibodies AT8, AT180, and AT270 in vivo. Thus PKN serves as a regulator of microtubules by specific phosphorylation of tau, which leads to disruption of tubulin assembly.

Amino Acid Sequence↗

PubMed2000

Prognostic value of genetically diagnosed lymph node micrometastasis in non-small cell lung carcinoma cases.

The predictive value of lymph node micrometastasis, detected by immunohistochemical or genetic methods, is well appreciated in terms of prognosis. However, a major problem is high false-positive rates, because most methods focus on cytokeratin, which is a component not only of carcinoma but also normal epithelial and nonepithelial cells. Mutant allele-specific amplification (MASA) can detect DNAs derived from cancer cells itself, reportedly with high sensitivity. It was, therefore, used with nested-PCR using p53 or K-ras mutation for analysis of lymph node micrometastasis in non-small cell lung carcinoma (NSCLC) patients in the present study, in comparison with the immunohistochemical method using an anti-cytokeratin reagent for the same samples. Lymph nodes from 31 NSCLC patients with p53 and K-ras mutated tumors (30 and 1, respectively) staged as pathological (p)-T1-4 N0-1 and M0 were examined. Genetic and immunohistochemical methods demonstrated positive reactions in 34 (15%) and 61 (27%) of 229 lymph nodes, respectively (9 cases, 29%, and 24 cases, 77%). The concordance with the two methods was 77%, but 13 (39%) of 34 genetically positive lymph nodes could not be detected by immunohistochemistry (IHC). Of 22 cases with p-N0 disease, 6 (27%) were genetically positive in hilar and/or mediastinal lymph nodes, and 4 (67%) of them died after cancer relapse. In contrast, none of the patients without micrometastasis died of cancer (P < 0.001, log rank analysis). Of the same p-N0 patients, 17 (77%) were positive by IHC, and 4 (24%) of them died of cancer, whereas 5 negative patients did not suffer cancer relapse. Survival did not significantly differ between cases positive and negative (P = 0.246) by IHC. According to the g-N (N factor restaged by a genetic method), patients with g-N1 and g-N2 disease had a shorter survival than those with g-N0 disease (P = 0.042 and P < 0.001, respectively). However, no significant difference was observed with grading by IHC. Thus, detection of micrometastasis in regional lymph nodes with the MASA method, in other words with a carcinoma-specific marker, is of greater prognostic significance for early stage NSCLC patients than immunohistochemical results. This approach should facilitate selection of patients for whom postoperative adjuvant chemotherapy should be performed.

Adenocarcinoma↗

PubMed2000

Less extrahepatic induction of fatty acid beta-oxidation enzymes by PPAR alpha.

The peroxisome proliferator-activated receptor alpha (PPAR alpha) is a nuclear receptor that transcriptionally regulates mitochondrial and peroxisomal fatty acid beta-oxidation enzymes in the liver. Ligands include synthetic peroxisome proliferators and some fatty acids. PPARalpha activation leads to predictable pleiotropic responses in liver including peroxisome proliferation, increased fatty acid oxidation, and hepatocellular carcinoma. In the current study, the response to PPAR alpha-activation was compared in the heart, kidney, and liver since the role of PPAR alpha in extrahepatic fatty acid-oxidizing organs has not been fully explored. Basal expression of mitochondrial beta-oxidation enzymes was comparable in the three tissues, but peroxisomal beta-oxidation enzymes were most abundant in the liver and less so in the kidney and especially in the heart. After PPAR alpha activation with ciprofibrate, both mitochondrial and peroxisomal beta-oxidation enzymes were induced, with the strongest response seen in the liver, a moderate response in the kidney, and no significant response in the heart. PPAR alpha mRNA analysis suggested that the differential response may be related to PPAR alpha expression.

Animals↗

PubMed2000

Paraspinal motor evoked potentials by magnetic stimulation of the motor cortex.

The authors studied five patients with MS and four patients with HTLV-1 associated myelopathy (HAM) to investigate the usefulness of paraspinal motor evoked potentials (MEP) after magnetic stimulation of the motor cortex. In patients with MS, MEP disappeared or onset latencies were delayed below the lesion. In patients with HAM, the onset latencies were prolonged bilaterally. Thus, paraspinal MEP are very useful in detecting spinal cord lesions.

Adult↗

PubMed2000

Defect in peroxisome proliferator-activated receptor alpha-inducible fatty acid oxidation determines the severity of hepatic steatosis in response to fasting.

Fasting causes lipolysis in adipose tissue leading to the release of large quantities of free fatty acids into circulation that reach the liver where they are metabolized to generate ketone bodies to serve as fuels for other tissues. Since fatty acid-metabolizing enzymes in the liver are transcriptionally regulated by peroxisome proliferator-activated receptor alpha (PPARalpha), we investigated the role of PPARalpha in the induction of these enzymes in response to fasting and their relationship to the development of hepatic steatosis in mice deficient in PPARalpha (PPARalpha(-/-)), peroxisomal fatty acyl-CoA oxidase (AOX(-/-)), and in both PPARalpha and AOX (double knock-out (DKO)). Fasting for 48-72 h caused profound impairment of fatty acid oxidation in both PPARalpha(-/-) and DKO mice, and DKO mice revealed a greater degree of hepatic steatosis when compared with PPARalpha(-/-) mice. The absence of PPARalpha in both PPARalpha(-/-) and DKO mice impairs the induction of mitochondrial beta-oxidation in liver following fasting which contributes to hypoketonemia and hepatic steatosis. Pronounced steatosis in DKO mouse livers is due to the added deficiency of peroxisomal beta-oxidation system in these animals due to the absence of AOX. In mice deficient in AOX alone, the sustained hyperactivation of PPARalpha and up-regulation of mitochondrial beta-oxidation and microsomal omega-oxidation systems as well as the regenerative nature of a majority of hepatocytes containing numerous spontaneously proliferated peroxisomes, which appear refractory to store triglycerides, blunt the steatotic response to fasting. Starvation for 72 h caused a decrease in PPARalpha hepatic mRNA levels in wild type mice, with no perceptible compensatory increases in PPARgamma and PPARdelta mRNA levels. PPARgamma and PPARdelta hepatic mRNA levels were lower in fed PPARalpha(-/-) and DKO mice when compared with wild type mice, and fasting caused a slight increase only in PPARgamma levels and a decrease in PPARdelta levels. Fasting did not change the PPAR isoform levels in AOX(-/-) mouse liver. These observations point to the critical importance of PPARalpha in the transcriptional regulatory responses to fasting and in determining the severity of hepatic steatosis.

Animals↗

PubMed2000

Auditory cortex responds in 100 ms to incongruity of melody.

In order to find the cortical neural activities that reflect musical processing, we conducted measurements of MEG responses while subjects listened to familiar melodies. Significant enlargement of the N1m peak was observed in the response to the endnote of a phrase that was deviated to out-of-key from the keynote. Equivalent current sources of the enlarged N1m response were localized in the cortical area of the superior temporal plane. These results suggest the possibility of fast neural processing, as early as 100 ms, of the auditory cortex detecting incongruity of a melody.

Adult↗