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Biomedical subjects

M Hashimoto

Publications and source records attributed to M Hashimoto.

At least 1,351 records · Page 75Linked to original sources
PubMedDate not supplied

Successful treatment of a ruptured infected aneurysm of the lumbar artery with transcatheter embolization.

We report a patient who had an infected aneurysm of the lumbar artery caused by prolonged psoas abscess-forming spondylitis due to methicillin-resistant Staphylococcus aureus and who was treated successfully with transcatheter arterial embolization. This case suggests that an infected aneurysm can be treated successfully by transcatheter arterial embolization in emergent situations (active bleeding or septicemia) even if surgery is contraindicated.

Aneurysm, Infected↗
PubMedDate not supplied

Minimal-deviation adenocarcinoma (adenoma malignum) of the uterine cervix; four case reports.

Four cases of minimal-deviation adenocarcinoma (adenoma malignum) of the uterine cervix are analysed in this clinicopathological study. Four patients, one Ib, two IIb and one IIIb stage, showed poor prognosis, which included three patients who died within 36 months, because of diagnostic delays of 5 years, 6 months and 1 year due to cytohistologically benign appearances. Cytologically, the nuclei were somewhat more irregular in size and shape than those of normal columnar epitherial cells. Slightly multilayered cell clusters were arranged as honeycombs, palisades or sheets with glandular openings. The characteristic histological features were the presence of sharp points projecting from the glands and marked variation in the size and shape of the glands. Ultrastructurally, intestinal metaplastic cells containing both microvilli with core filaments and rootlets, and secretary granules in the same cell were present in the specimens of two evaluable patients. These features indicate a disorder of differentiation. In order to diagnose this tumor accurately, comprehensive analysis should be required concerning the clinical features, cytohistological findings and ultrastructural findings.

Adenocarcinoma↗
PubMedDate not supplied

The propensity to malignancy of dispermic heterozygous moles.

Complete hydatidiform moles may originate from either the fertilization of an empty egg by a haploid sperm followed by duplication (producing a monospermic, homozygous mole) or the fertilization of such an egg by two haploid sperms (producing a dispermic, heterozygous mole). This difference in the mechanism leading to the formation of complete moles raises the question of whether the risk of subsequent malignancy is influenced by the zygosity of the mole. We have compared the incidence of postmolar sequelae in patients with homozygous and heterozygous moles. Using chromosomal heteromorphisms, human lymphocyte antigen (HLA) and phosphoglucuromutase 1 (PGM1) polymorphisms, we established the androgenetic origin of complete mole in 84 of 91 cases. Homozygosity was confirmed in 51 moles, and we found ten heterozygous moles. Five of ten patients with heterozygous moles developed postmolar trophoblastic disease, whereas only two of the 51 patients with homozygous moles had postmolar trophoblastic disease (an additional five patients showed signs of degenerating residual trophoblasts). The XY sex chromosome constitution of the two in vitro choriocarcinoma cell lines examined here provides further evidence of the propensity to malignancy of heterozygous moles.

Choriocarcinoma↗
PubMedDate not supplied

Frontal distribution of early cortical somatosensory evoked potentials to median nerve stimulation.

The topography of early frontal SEPs (P20 and N26) to left median nerve stimulation was studied in 30 normal subjects and 3 patients with the left frontal bone defect. The amplitudes of P20 and N26 were maximum at the frontal electrode (F4) contralateral to the stimulation and markedly decreased at frontal electrodes ipsilateral to the site of stimulation. There was, however, no latency difference of P20 and N26 between ipsilateral and contralateral frontal electrodes. These results suggest that the origin of the ipsilateral and contralateral P20 and N26 is the same. The wide distribution of P20 and N26 over both frontal areas could be explained by assuming a smearing effect from generators actually located in the rolandic fissure and motor cortex.

Adult↗
PubMedDate not supplied

Alterations of plasma immunoreactive glucagon-like peptide-1 behavior in non-insulin-dependent diabetics.

The basal level of plasma immunoreactive glucagon-like peptide-1 (IR GLP-1) was significantly elevated in non-insulin-dependent diabetics (NIDD), and this elevation of IR GLP-1 was mainly due to an increase in the large component of IR GLP-1, corresponding to the pancreatic form. During the oral glucose-tolerance test (OGTT), the total plasma IR GLP-1 decreased in normal subjects but increased significantly in diabetic patients. Chromatographic analysis showed that IR GLP-1 consisted of several different molecular forms. OGTT caused a decrease in the pancreatic form but increased the intestinal form in normal subject, resulting into a net decrease in total plasma IR GLP-1. Whereas in NIDD the increase in the intestinal form was more prominent and the suppression of the pancreatic form was practically abolished to result in a net increase of total plasma IR GLP-1. This observation is consistent with the fact that in normal subjects the total change in IR GLP-1 was significantly correlated with both the total change of gut glucagon as well as that of pancreatic glucagon, but in diabetics the total change of GLP-1 only correlated to that of gut glucagon. The impaired suppression of pancreatic GLP-1 and enhanced release of intestinal GLP-1 could have some physiological importance in NIDD.

Blood Glucose↗
PubMedDate not supplied

Enzyme properties of monoamine oxidase in the frontal cortex and liver of the gerbil (Meriones unguiculatus).

1. Enzyme properties of monoamine oxidase (MAO) in the frontal cortex and liver of the gerbil were investigated using 5-hydroxytryptamine (5-HT), benzylamine (Bz) and tyramine (Tyr) as substrates. 2. The Km values of MAO towards the three substrates were almost similar to the values in other species. The Vmax value of MAO towards Bz was much lower than the value towards 5-HT. 3. In the inhibition studies with selective MAO-A and MAO-B inhibitors, clorgyline and deprenyl, deamination of 5-HT, Bz and Tyr in both tissues was induced by MAO-A alone, MAO-B alone and both forms of the enzyme, respectively, indicating the same substrate specificity as that in rats. 4. The apparent proportion of MAO-A to MAO-B activities in the gerbil liver was approximately 6:4, whereas MAO-A in the frontal cortex of the gerbil was exclusively predominant, consistent with the previous data in the golden hamster which belongs to the same family as the gerbil.

Animals↗
PubMedDate not supplied

The results of serial dynamic enhanced computed tomography in patients with carotid-cavernous sinus fistulas.

PURPOSE: To assess serial dynamic enhanced computed tomography (serial DE-CT) as a diagnostic tool for carotid-cavernous sinus fistula (CCF). METHODS: Serial DE-CT was performed in seven patients (ages 31-74) with CCF. Contrast material was injected intravenously at a dose of 60 mL with an injection speed of 4 mL per second. Serial axial images of the cavernous sinus were undertaken every 3 seconds using a helical computed tomography system. This relatively low-risk technique provides direct evidence of the arteriovenous shunt in the cavernous sinus. RESULTS: In early imaging after the injection, enhancement of the cavernous sinus on the side of the CCF was noted at the arterial phase in all patients, whereas early enhancement of the cavernous sinus was not observed on the contralateral uninvolved side. CONCLUSIONS: These findings suggest the usefulness of serial DE-CT as a diagnostic tool for the initial diagnosis of both high- and low-flow CCFs.

Adult↗
PubMedDate not supplied

Over-etching effects on micro-tensile bond strength and failure patterns for two dentin bonding systems.

OBJECTIVES: The purpose of this study was to determine (1) the weakest zone of resin-dentin bonds and (2) the relation between bond strength and failure mode to clarify the effect of demineralized dentin. METHODS: Human premolars were sectioned to expose the dentin surfaces, and the dentin surfaces were conditioned with phosphoric acid for 15, 60, 120, or 180s. Resin-dentin bonded specimens were produced using two adhesives: One-Step (Bisco) and OptiBond Solo (Kerr). Each sample was sectioned to produce a beam (adhesive area: 0.9mm(2)). Microtensile bond tests were then conducted, and the mean bond strengths (n=12 for each group) were statistically compared using two-way ANOVA and Duncan's multiple-range test (p<0.05). The fractured surfaces of all specimens were examined using SEM, and the areas of failure were measured using an image analyzer. RESULTS: For One-Step, the bond strength decreased with increase in acid-conditioning time (15s: 50.7+/-9.7, 60s: 40.8+/-11.0, 120s: 23.6+/-4.9 and 180s: 12.1+/-4.6MPa) (p<0.05). For OptiBond Solo, the bond strength in the case of 15s acid-conditioning time (42.6+/-7.9MPa) was significantly greater than that for the other times (60s: 31.9+/-10.3, 120s: 31.8+/-14.4 and 180s: 31.8+/-7.4MPa) (p<0.05). Fractography showed that the area percentage of the hybrid layer increased with increase in etching time for both systems. CONCLUSIONS: The integrity of the hybrid layer, especially the top part, has an effect on bond strength.

Acid Etching, Dental↗
PubMedDate not supplied

Aging decreases the production of PGI2 in rat aortic endothelial cells.

It has been suggested that progressive pathophysiologic modifications of endothelium are associated with aging. Aging has been shown to influence some specific functions at the cellular level. In the present study, the effects of aging on levels of prostacyclin (PGI2) production were examined in cultured rat aortic endothelial cells from young (six-week-old) and old (100-week-old) Wistar rats. The level of PGI2 production from rat aortic endothelial cells decreased significantly with increasing age, suggesting decreased function of the endothelial cells. The production of PGI2 stimulated by thrombin was decreased in old rat aortic endothelial cells compared to young rat aortic endothelial cells, whereas there was no difference in the rate of intracellular calcium mobilization caused by thrombin. These data indicate that aging nonuniformly affects both basal and agonist-induced levels of PGI2 production in rat aortic endothelial cells, and that this diminution in PGI2 production may be related to the age-related potentiation of various thrombotic events.

Aging↗
PubMedDate not supplied

Comparison of MR imaging and CT in discriminating tumor infiltration of bone and bone marrow in the skull base.

We compared MR imaging with CT in revealing tumor infiltration of bone and bone marrow in the skull base of 54 patients. MR imaging had no advantages over when tumor involved the anterior compartment. However, precontrast T1-weighted MR images were more efficient than CT in 37.5% of tumors involving the middle compartment and in 54.5% of tumors involving the posterior compartment, respectively. Precontrast T1-weighted images were more accurate than other pulse sequences in revealing bone and bone marrow that were replaced by tumors.

Adenoma↗
PubMedDate not supplied

Age-related changes in platelet microviscosity and aggregation in rats.

1. To study possible changes in platelet microviscosity in aged animals, 1,6-diphenyl-1,3,5-hexatriene (DPH) was used as a nonpolar probe embedded in thrice-washed platelets from young, adult and aged rats. With the known values of maximum limiting anisotropy and the structural parameter of DPH and by estimating the steady state of fluorescence anisotropy and the average fluorescence of lifetime, we applied the Perrin equation to calculate the microviscosity. 2. We measured platelet aggregation, platelet lipids and platelet polyunsaturated fatty acids to determine any causal relationship between these parameters. Platelet aggregation, the platelet molar ratio of cholesterol to phospholipid ([C]/[PL]) and platelet microviscosity increased with age (P < 0.05) and were correlated with one another (P < 0.05). 3. Age-dependent increases in the steady state of fluorescence anisotropy, order parameters and the short component of fluorescence lifetime of the fluorophore were expressed as functions of variables, such as microviscosity or the [C]/[PL] ratio. 4. Platelet concentrations of arachidonic and eicosapentaenoic acids increased with age, but were not associated with aggregation. Age-related changes in microviscosity and the [C]/[PL] ratio seemed to be determinants affecting biophysical properties of platelet aggregation.

Aging↗
PubMedDate not supplied

Sodium sensitivity and sympathetic nervous system in hypertension induced by long-term nitric oxide blockade in rats.

1. Pharmacological inhibition of nitric oxide (NO) synthesis is known to produce acute and chronic hypertension in many animal species, but the underlying mechanisms mediating the hypertension are not completely understood. In particular, the pathogenetic roles of sodium sensitivity and the sympathetic nervous system in this model of hypertension are controversial. The present study was designed to test the hypothesis that long-term administration of the NO synthesis inhibitor NG-nitro-L-arginine methyl ester (L-NAME) to male Sprague-Dawley rats would produce a sodium-sensitive hypertension and that the enhanced activity of the sympathetic nervous system in this type of hypertension contributes to the sodium sensitivity. 2. NG-Nitro-L-arginine methyl ester was added to drinking fluid for 8 weeks at a concentration of 16 mg/dL. Rats received tap water for the first 4 weeks of the study and were then divided into two groups and placed on either a normal or high sodium intake (ingestion of either tap water or 0.9% NaCl, respectively). Awake systolic blood pressure was measured by the tail-cuff method every week. Urinary excretion rates of the stable NO metabolites and catecholamines during NO synthesis inhibition were examined. 3. Long-term administration of L-NAME produced a marked and sustained elevation in arterial pressure without altering urine flow, or sodium excretion rate. NG-Nitro-L-arginine methyl ester-induced hypertension was accompanied by a decreased urinary excretion of the stable NO metabolites NO2- and NO3- and was aggravated when rats drank 0.9% NaCl in place of tap water. Urinary excretion of adrenaline and noradrenaline, but not dopamine, in L-NAME-treated rats increased significantly within the first week of the study compared with control rats. L-Arginine (2 g/dL in drinking fluid) completely reversed the elevation of arterial pressure as well as the decrease in urinary NO2- and NO3- excretion and the increased urinary excretion of catecholamines associated with L-NAME treatment by 3 weeks of concomitant administration. 4. These results suggest that long-term inhibition of NO synthesis produces a sodium-sensitive hypertension and that changes in sympathetic nerve activity may, at least in part, contribute to the sodium sensitivity in this type of hypertension.

Animals↗
PubMedDate not supplied

Use of iron colloid-enhanced MRI for study of acute radiation-induced hepatic injury.

We present a case with acute radiation-induced hepatic injury using chondroitin sulfate iron colloid (CSIS)-enhanced MRI. Uptake of CSIC was decreased in the irradiated portion of the liver. CSIC-enhanced MRI is useful for obtaining information on the function of the reticuloendothelial system and demarcates between irradiated and nonirradiated zones.

Acute Disease↗
PubMedDate not supplied

Intraosseous ganglion of the metatarsal bone.

We describe a rare case of intraosseous ganglion arising in the metatarsal bone. Radiographs revealed an osteolytic lesion with a fracture in the third metatarsal bone. A biopsied specimen exhibited hyaline fibrous tissue with marked myxoid change. Gadolinium-enhanced MRI, which revealed the network-like enhancement of the rim of the lesion and polycystic lesions adjacent to the joint, was helpful in making a diagnosis of intraosseous ganglion.

Biopsy↗