Stasis ulcer and dermatitis caused by artificial arteriovenous fistula created 33 years previously for the treatment of poliomyelitis.
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Adult↗
Biomedical subjects
H Isoda
Publications and source records attributed to H Isoda.
Visualization of hemodynamics in a silicon aneurysm model using time-resolved, 3D, phase-contrast MRI.
We performed time-resolved 3D phase-contrast MR imaging by using a 1.5T MR scanner to visualize hemodynamics in a silicon vascular model with a middle cerebral aneurysm. We ran an aqueous solution of glycerol as a flowing fluid with a pulsatile pump. Time-resolved images of 3D streamlines and 2D velocity vector fields clearly demonstrated that the aneurysm had 3D complex vortex flows within it during systolic phase. This technique provided us with time-resolved 3D hemodynamic information about the intracranial aneurysm.
Aged↗
Expressions of galectin-3, glutathione S-transferase A2 and peroxiredoxin-1 by nonylphenol-incubated Caco-2 cells and reduction in transepithelial electrical resistance by nonylphenol.
Nonylphenol, an estrogenic xenobiotic widely used in the manufacture of plastics and detergents, has been found in drinking water and may therefore enter the body through the oral route. Thus, intestinal cells lining the alimentary tract serve as the body's first line of defense against this compound. In this study, the effects of nonylphenol on the human intestinal cell line Caco-2 were determined using transepithelial electrical resistance (TEER) measurement and proteomics. Results show that 10 microM nonylphenol can disrupt the tight-junction permeability of Caco-2 cells in approximately 15 min. Incubating the cells with 1 or 10 microM nonylphenol for 6 days resulted in the enhanced expressions of galectin-3 (approximately 4-fold vs. control with 1 microM; 2-fold with 10 microM), glutathione S-transferase A2 (approximately 8-fold with 1 microM; 5-fold with 10 microM) and peroxiredoxin-1 (approximately 6-fold with 1 microM; 4-fold with 10 microM). These expressions may represent a possible consortium of mechanisms by which the cells protect themselves against nonylphenol-induced stresses. To the best of our knowledge, this is the first study on the effects of nonylphenol on Caco-2 cells.
Caco-2 Cells↗
Ideographic characters call for extra processing to correspond with phonemes.
Cortical areas used in the copying of Japanese ideographic characters and syllabic characters were studied using functional magnetic resonance imaging in healthy volunteers. Complexity of characters was controlled to illustrate differences resulting from character to sound conversion differences between the ideographic and syllabic characters. Statistical comparisons indicated extensive activation in the fusiform gyrus, posterior portions around the intraparietal sulcus and in the conjunction area of BA 6, 9 and 44 (which is assumed to be Exner's area) during the copying of ideographic characters. These findings suggested that indirectness between ideographic characters and their pronunciation demands extra processing such as semantic mediation and intensive grapheme processing in comparison with syllabic characters.
Adult↗
Long-term audiological feature in Pendred syndrome caused by PDS mutation.
Pendred syndrome is an autosomal recessive disorder characterized by profound deafness in childhood and goiter. We report a case of Pendred syndrome in a 27-year-old woman who had a diffuse goiter and progressive sensorineural hearing loss with fluctuation and a missense mutation (His723Arg) in the PDS gene identified in a homozygous state. Audiological findings were observed clinically over a 20-year period. Progressive hearing loss with fluctuation occurred before age 12 years. An enlarged vestibular aqueduct with enlargement of the endolymphatic duct and sac was confirmed with 3-dimensional magnetic resonance imaging hydrography.
Adult↗
Dynamic gadolinium-enhanced MR imaging of pituitary adenomas: usefulness of sequential sagittal and coronal plane images.
Dynamic magnetic resonance (MR) imaging for pituitary adenomas is usually performed in a coronal direction; however, small lesions between slices, or lesions located at the anterior or posterior aspect of the pituitary gland might be overlooked on MR images in only the coronal direction. The purpose of our study was to evaluate whether consecutive dynamic MR images in the coronal and sagittal planes improve detection of pituitary adenomas. Eighteen patients with pituitary microadenomas and nine with healthy pituitary glands were included in this study. MR images were performed with 1.5 T superconductive units and commercially-available head coils. After a 5 ml gadolinium contrast injection, eight serial dynamic sagittal images were obtained. Within 3 or 6 min, this was followed by a 10-15 ml gadolinium injection and acquisition of eight serial dynamic coronal images. Dynamic MR images and conventional noncontrast- and contrast-enhanced sagittal and coronal T1-weighted images were evaluated independently in a blind fashion by two neuroradiologists regarding the depiction of pituitary microadenomas. The sensitivities of dynamic enhanced MR imaging in the detection of microadenomas were 61.1% in sagittal direction, 72.2% in coronal direction respectively, and were superior to those of conventional noncontrast- and contrast-enhanced T1-weighted imaging (22.2-50%). The sensitivity of a combination of sagittal and coronal dynamic enhanced MR imaging for the detection of microadenomas was 88.9% and was superior to those of conventional noncontrast- and contrast-enhanced T1-weighted imaging combining sagittal and coronal directions (61.1%, 61.1%) (P<0.05, P<0.05, respectively). The specificity and accuracy of dynamic enhanced MR imaging with combination of sagittal and coronal images was 88.9% respectively. Dynamic gadolinium-enhanced MR imaging, especially using both sagittal and coronal planes, was concluded to be useful for the detection of pituitary microadenomas.
Adenoma↗
Vasospasms are characteristic in cases with eclampsia/preeclampsia and HELLP syndrome: proposal of an angiospastic syndrome of pregnancy.
We attempted to prove the occurrence of generalized vasospasms in cases with eclampsia/preeclampsia and HELLP syndrome and to suggest the existence of an angiospastic syndrome of pregnancy. Sixteen cases with severe preeclampsia were evaluated. Among them, three cases were complicated by eclampsia and one case with HELLP syndrome. Cranial magnetic resonance angiography (MRA) was performed in 15 cases, and celiac angiography was performed in one case. Vasospasms were observed in 12 cases (75.0%), including all cases involving eclampsia and HELLP syndrome, and cerebral infarction was observed in one case. Typical vasospasms were found by MRA in the middle and posterior cerebral arteries with peripheral ischemic changes in cases with severe preeclampsia and eclampsia. Vasospasms of the hepatic arteries were observed by celiac angiography in a case with HELLP syndrome. Vasospasms are characteristic for patients with eclampsia/preeclampsia and HELLP syndrome, and the existence of an angiospastic syndrome of pregnancy is proposed.
Adult↗
Assessment of gadolinium-enhanced time-resolved three-dimensional MR angiography for evaluating renal artery stenosis.
OBJECTIVE: The purpose of this study was to assess the image quality of gadolinium-enhanced time-resolved three-dimensional (3D) MR angiography and to evaluate its accuracy in revealing renal artery stenosis. SUBJECTS AND METHODS: Thirty-nine patients underwent MR angiography using an ultrafast 3D Fourier transform spoiled gradient-recalled acquisition in the steady state (TR/TE range, 2.6/0.7--0.8). Five seconds after administration of 15--20 mL gadodiamide hydrate, four or five consecutive data sets with imaging times of 7.0--7.6 sec were acquired during a single breath-hold. A timing examination was not performed. Image quality was assessed using quantitative analysis (signal-to-noise, contrast-to-noise, and venous-to-arterial enhancement ratios) and qualitative analysis (presence of venous overlap, presence of artifacts, and degree of renal arterial enhancement). MR angiography depiction of the renal artery stenosis was evaluated using conventional angiography as the standard of reference. RESULTS: On the best arterial phase, average aortic signal-to-noise ratio (+/-SD) was 74.5 +/- 24.4, aorta-to--inferior vena cava contrast-to-noise ratio was 70.8 +/- 23.4, and inferior vena cava--to-aorta venous-to-arterial enhancement ratio was 0.03 +/- 0.04. No venous overlap was seen in 38 of 39 patients. Substantial enhancement of renal arteries was seen in all patients without any noticeable artifacts. MR angiography correctly depicted the degree of stenosis in 44 of 47 normal arteries, 13 of 16 mildly stenotic arteries, five of five moderately stenotic arteries, three of four severely stenotic arteries, and one of one occluded artery. Sensitivity and specificity for revealing greater than 50% stenosis was 100%. CONCLUSION: Time-resolved 3D MR angiography can provide high-quality arteriograms. Its performance in revealing renal artery stenosis is comparable with that of conventional angiography.
Adult↗
The effects of listening comprehension of various genres of literature on response in the linguistic area: an fMRI study.
Using fMRI at a static magnetic field strength of 1.5T, we investigated how comprehension and humor of sentences would correlate to activation of the language areas in listening comprehension of a native language. Sentences with a high comprehension score augmented activation in the left inferior parietal lobule and posterior part of the left superior temporal gyrus, which may be related to semantic processing. Sentences with a high humor score induced activation in Broca's area, which may be associated with syntactic processing and auditory working memory. Furthermore, sentences with a high humor factor and/or a low comprehension score activated the middle frontal gyrus, which may be attributed to auditory working memory.
Adult↗
Proton magnetic resonance spectroscopy of lenticular nuclei in simple schizophrenia.
1. The lenticula nuclei have been suggested to be the site of structural and functional abnormalities in schizophrenia. 2. Recently, several studies involving proton magnetic resonance spectroscopy (1H MRS) showed that the ratio of N-acetyl-aspartate (NAA) to choline-containing compounds (Cho) was significantly reduced in the basal ganglia region in patients with schizophrenia. 3. Simple schizophrenia is characterized by social withdrawal and affective flattening, but not by prominent catatonic, hebephrenic or paranoid features. 4. We studied, using 1H MRS, the lenticula nuclei of 10 patients with simple schizophrenia, and 10 age- and sex-matched healthy controls. 5. No differences between the patients and the controls were found in any of the measured ratios, i.e. Cho/Cr, NAA/Cr and NAA/Cho. 6. Our results suggest the normal viability of neuronal cells, as found on quantification of NAA, Cr and Cho, in the lenticular nuclei of patients with simple schizophrenia. 7. The pathophysiology of simple schizophrenia may be different from those of other types of schizophrenia.
Adult↗
Post-stimulus response in hemodynamics observed by functional magnetic resonance imaging--difference between the primary sensorimotor area and the supplementary motor area.
The blood oxygen level dependency (BOLD) contrast is a useful tool for functional neuroimaging based on the hemodynamic response to neuronal activation. We observed different hemodynamic responses in the BOLD signal between the primary sensorimotor area (SM1) and the supplementary motor area (SMA) in the sequential finger movement task. In the SMA, a stronger initial overshoot and a post-stimulus overshoot were observed. It was hypothesized from the time course analysis that the stronger initial overshoot reflected the activation of the SMA for motor control programming in the initial phase. Although the post-stimulus overshoot may be partially explained by cerebral blood flow (CBF) cerebral blood volume (CBV) uncoupling, its mechanism remained unknown. In the SM1, only the initial overshoot was observed and the level of BOLD signal was almost constant after the initial overshoot during the task period. These observations suggested that the BOLD signal is characterized by both CBF-CBV uncoupling and the neuronal activation characteristics in each region.
Adult↗
Dissociation of writing processes: functional magnetic resonance imaging during writing of Japanese ideographic characters.
Dissociation between copying letters and writing to dictation has been reported in the clinical neuropsychological literature. Functional magnetic resonance imaging (fMRI) was conducted in normal volunteers to detect the neurofunctional differences between 'copying Kanji', the Japanese ideographic characters, and 'writing Kanji corresponding to phonological information'. Four tasks were conducted: the copying-Kanji task, the writing-Kanji-corresponding-to-phonogram task, the Kanji-grapheme-puzzle task, and the control task. The right superior parietal lobule was extensively activated during the copying-Kanji task (a model of the copying letters process) and the Kanji-grapheme-puzzle task. These observations suggested that this area was involved in referring the visual stimuli closely related to the ongoing handwriting movements. On the other hand, Broca's area, which is crucial for language production, was extensively activated during the writing-Kanji-corresponding-to-phonogram task (a model of the writing-to-dictation process). The Kanji-grapheme-puzzle task activated the bilateral border portions between the inferior parietal lobule and the occipital lobe, the left premotor area, and the bilateral supplementary motor area (SMA). Since the Kanji-grapheme-puzzle task involved manipulospatial characteristics, these results suggested cooperation between visuospatial and motor executive functions, which may be extensively utilized in demanding visual language processing. The neurofunctional difference between 'copying Kanji' and 'writing Kanji corresponding to phonogram' was efficiently demonstrated by this fMRI experiment.
Adult↗
Consecutive imaging of the facial nerve using high-resolution magnetic resonance imaging.
This study examined the signal intensity of the facial nerve on T1-weighted images using the multiplanar reconstruction (MPR) method of the high-resolution magnetic resonance imaging technique. The facial nerves of 12 sides in 6 normal adults were consecutively observed from the mastoid area to the intraparotid area. Results indicated that facial nerves showed similar or relatively high signal intensity compared with the intensity of the parotid parenchyma. Although previous studies have indicated that the intraparotid facial nerve had a low signal intensity, facial nerves were probably confused with the intraparotid ductal system or vessels which show low signal intensity on T1-weighted images or with low signal lines due to chemical artifacts. All facial nerve trunks were clearly identified; however, 33% (4/12) of second branches of the nerves shifted or curved too strongly to be detected in the parotid parenchyma with this method.
Adult↗
Inhibitory effects of bovine lactoferrin on the adherence of enterotoxigenic Escherichia coli to host cells.
Adherence is an essential and prerequisite step for the colonization of mucosal surfaces by enterotoxigenic Escherichia coli (ETEC). We studied the effect of bovine lactoferrin (BLF) on the adherence of ETEC to human epithelial cells in vitro, and to intestinal mucosa of ICR germfree mice in vivo. In the in vitro study, BLF was found to inhibit the adherence of ETEC. This adhesion-inhibiting activity of BLF was found to lessen with decreasing BLF concentration, but the data obtained suggest a positive inhibitory effect of BLF against the adhesion of ETEC cells. In the in vivo study, the counts of adherent bacteria in various sections of the intestinal tract (duodenum, jejunoileum, and large intestine) were lower in the BLF group than in the control group, suggesting the possible action of BLF as an intestinal tract adherence-blocking agent with regards to ETEC.
Animals↗
Software-triggered contrast-enhanced three-dimensional MR angiography of the intracranial arteries.
OBJECTIVE: We investigated the effectiveness of software-triggered contrast-enhanced three-dimensional (3D) MR angiography in evaluating intracranial arteries. SUBJECTS AND METHODS: We studied 38 patients with suspected brain lesions. Imaging was performed using a 1.5-T superconducting MR system with a commercially available head coil. To monitor signal intensity changes we used software to place a tracker volume at the basilar artery or the internal carotid artery. A 20-ml bolus of gadodiamide hydrate was administered through the antecubital vein at a rate of 2-4 ml/sec, followed by a saline flush. Three-dimensional MR angiography using a spoiled gradient-echo sequence with centric K-space ordering was triggered by the arrival of the contrast bolus in the tracker volume. Imaging times ranged from 12 to 20 sec. We used MR images to assess the effectiveness of contrast-enhanced 3D MR angiography in revealing intracranial arteries with minimal venous overlap. RESULTS: The software triggered imaging on the arrival of the contrast bolus in 81.6% of examinations. In 77.6% of examinations, the resulting MR angiograms revealed intracranial arteries with minimal venous overlap. CONCLUSION: Software-triggered contrast-enhanced 3D MR angiography with centric K-space ordering is a promising technique for viewing intracranial arteries.
Basilar Artery↗
Dynamic MR dacryocystography: a new method for evaluating nasolacrimal duct obstructions.
OBJECTIVE: The purpose of this study was to evaluate the clinical performance of newly implemented dynamic MR dacryocystography. CONCLUSION: Dynamic MR dacryocystography, which requires neither ionizing radiation nor chemical contrast media with high viscosity, may be a useful tool for depicting nasolacrimal obstructions.
Aged↗
Proton magnetic resonance spectroscopy of lenticular nuclei in obsessive-compulsive disorder.
Magnetic resonance spectroscopy (MRS) is a safe and non-invasive technique for the in vivo study of brain chemistry and metabolism. As such, it is highly applicable to the study of living brain tissue in psychiatric diseases. Several neuropathological and neuroimaging studies have suggested that abnormalities of the basal ganglia nuclei might be implicated in patients with obsessive-compulsive disorder (OCD). In the present study, we performed proton [1H]MRS of the lenticular nuclei in 12 patients with OCD and 12 healthy normal comparison subjects. The peaks of N-acetyl-aspartate (NAA), creatine (Cr), and choline-containing compounds (Cho) were measured. No differences between OCD patients and normal subjects were found in the NAA/Cr, Cho/Cr and NAA/Cho ratios. Our results suggest the normal viability of neuronal cells, as indicated by the quantification of NAA, Cr and Cho in the lenticular nuclei of patients with OCD.
Adult↗
Dynamic computed tomography predicts tumor temperature and response to thermoradiotherapy in superficial and subsurface tumors.
BACKGROUND: Dynamic computed tomography (CT) was performed on patients undergoing thermoradiotherapy for superficial or subsurface tumors, and the correlation between tumor enhancement and tumor temperature during hyperthermia was evaluated. The authors further investigated whether tumor enhancement by dynamic CT is predictive of tumor response to thermoradiotherapy. METHODS: Thermoradiotherapy was given to 26 patients. Radiotherapy consisted of 40-70 gray. Hyperthermia was conducted over 3-5 sessions, and tumor temperature was measured at each session. Dynamic CT was performed prehyperthermia (within 1 week before the initiation of hyperthermia) and midtherapy (within 1 week after 2 sessions of hyperthermia). RESULTS: A complete response (CR) was obtained in 11 patients (42%) and either a partial response or no response (non-CR) in 15 (58%). There was no correlation between tumor enhancement obtained by prehyperthermia CT and tumor temperature parameters or response. However, the deltaCTmax (maximum increased enhancement) by prehyperthermia and midtherapy CT was 39.0 +/- 18.9 HU and 26.1 +/- 14.2 HU, respectively, in CR patients, and 46.4 +/- 21.1 HU and 49.6 +/- 19.1 HU, respectively, in non-CR patients. This change in deltaCTmax at midtherapy was significantly different between groups (P < 0.01). The deltaCTmax ratio for prehyperthermia and midtherapy CT studies correlated with the average tumor temperature (P < 0.05). CONCLUSIONS: Tumor enhancement by prehyperthermia and midtherapy dynamic CT predicted tumor temperature during hyperthermia and response to thermoradiotherapy for superficial or subsurface malignancies.
Adult↗