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T Nishiguchi

Publications and source records attributed to T Nishiguchi.

At least 19 recordsLinked to original sources
PubMed1992

MRI changes in embolized meningiomas.

Study of the MRI changes that occur after superselective embolization of hypervascular meningiomas with Gelfoam powder (5 cases) and polyvinyl alcohol (PVA) particles 150-250 microns in size (4 cases) has indicated that, after embolization, meningiomas showed loss of the signal void, decrease in gadolinium-DTPA contrast enhancement, and prolonged T1 and T2. Shortening of T1 and T2 was seen in two patients with Gelfoam-embolized meningiomas in whom CT showed pooling of iodinated contrast medium in the tissue. In vitro experimental data demonstrated that the shortening of T1 and T2 was due to the iodinated contrast medium.

Aged↗
PubMed1992

A method for quantitative measurement of cerebral vascular permeability using X-ray CT and iodinated contrast medium.

Cerebral vascular permeability is an important consideration in treatment for intracranial tumours. We have developed a new method to measure the cerebral vascular permeability quantitatively using a conventional X-ray CT scanner and iodinated contrast medium. We have already applied our method in 50 cases of intracranial tumour and 5 cases, which establish the methodology, are demonstrated. Dynamic CT scanning of a section including the tumour and the superior sagittal sinus was performed over 40 min after bolus injection of contrast medium, and 25 images were acquired. Our theoretical model of contrast enhancement was applied to analyse time-density curves, and the following parameters were obtained: Ki (inward flux constant), Kb (backward flux constant), Vp (vascular plasma volume), and lambda (extracellular fluid space volume). Furthermore, functional maps were generated from parameters for each pixel. Changes in intra-arterial iodine concentration, required in our model, were measured from CT numbers in the superior sagittal sinus. We have investigated several aspects of our method. Histological findings in surgical specimens of intracranial tumours agreed well with the parameters obtained by our method. Vp was verified quantitatively by single photon emission computed tomography. Our method was shown to be reproducible. These results show that the parameters are useful for assessing tumours and in planning chemotherapy. Our method, which employs no special equipment, is readily available at any institution.

Adult↗
PubMed1992

Local blood flow changes in malignant brain tumours under induced hypertension.

Changes in tumour blood flow under an induced hypertensive state were examined in malignant brain tumours to know if the precondition for the effectiveness of induced hypertensive chemotherapy--relative increase in tumour blood flow--are fulfilled. Tumour blood flow was measured under both a resting and an induced hypertensive state in 12 patients with various malignant brain tumours (6 gliomas, 6 metastatic brain tumours) using xenon-enhanced computed tomography. The blood pressure was elevated 40% above the systemic blood pressure of the resting state by the infusion of angiotensin II. Tumour blood flow increased 30% on average above the normal brain tissue blood flow after the induction of an induced hypertensive state (p < 0.05). The tumour blood flow increased in 11 cases of malignant tumours, but decreased in one case with massive brain oedema after induced hypertension. The increase in blood flow was higher in hypervascular tumours and less in hypovascular tumours. Therefore, induced hypertensive chemotherapy probably will be more effective in hypervascular malignant brain tumours with small mass effects.

Adult↗
PubMed1992

An HRP study of the location of the motoneurons supplying the tensor veli palatini muscle of the rabbit.

Location of the motoneurons supplying the tensor veli palatini muscle of the rabbit was examined with the retrograde labeling technique following intramuscular injection of HRP. Labeled motoneurons were ipsilaterally located in the ventral or ventromedial portion of the rostral two-thirds of the motor trigeminal nucleus at the level of about 6.0 to 8.5 mm rostral to the obex. The location of the labeled motoneurons was ventromedial to the region supplying the masseter, the temporalis, and the medial pterygoid muscles and ventral to the region supplying the anterior digastric and the mylohyoid muscles, the location which coincided with the lateral pterygoid region. The labeled motoneurons were scattered around or in this region.

Animals↗
PubMed1992

Chitinous components of the cell wall of Fusarium oxysporum.

The cell wall of Fusarium oxysporum f. sp. lycopersici was digested with chitinase to analyze the structure of its chitinous components. In spite of a similar acetylation degree of the cell wall components to that of 25-35% acetylated chitosan, only N-acetylglucosamine disaccharide [(GlcNAc)2] was obtained from chitinase hydrolyzate of the fungal cell wall by CM-Sephadex C-25 column chromatography, while (GlcNAc)2 and several types of deacetylated chitooligosaccharides were separated from that of 25-35% acetylated chitosan. The results indicate that N-acetylglucosamine residues in the polysaccharide chains of the fungal cell wall are most likely condensed into some region, while acetylated residues are more scattered in 25-35% acetylated chitosan.

Carbohydrate Sequence↗
PubMed1992

[Pitfalls of endovascular treatment for cerebral aneurysms].

Seventeen cases of unclippable aneurysms were treated by the endovascular balloon technique. Nine of them involved the anterior circulation, and eight involved the posterior circulation. Eleven of them were treated by parent artery occlusion with detachable balloons. Three were treated by endosaccular balloon embolization, and three cases combined with AVMs were occluded using ethylene vinyl alcohol copolymer (EVAL) including feeding arteries of the AVMs. Embolic complications occurred in one case of an IC bifurcation giant aneurysm treated by parent artery occlusion. Ischemic complications also appeared in two cases of aneurysms treated by endosaccular balloon embolization. In one case, the thrombus in the aneurysm propagated into the parent artery and occluded it later. In another case, the displaced balloon had obliterated the parent artery 6 hours after the embolization. Parent artery occlusion is a safe way to treat internal carotid giant aneurysms. However, endosaccular treatment still has some problems, i.e., 1) maintaining the balloon's position to preserve the parent artery, 2) balloon migration into the clot, 3) rupture of the aneurysm during or after treatment. Our studies indicate that endosaccular balloon embolization is still a high risk procedure and should be used only in selected cases, until new embolic agents, such as detachable coils, become available.

Adult↗
PubMed1992

[Clinical usefulness of carcinoembryonic antigen measurement in nipple discharge as an adjunctive tool for diagnosis of breast cancer].

We measured carcinoembryonic antigen (CEA) in 43 cases with abnormal nipple discharge by means of enzyme immunoassay utilizing monoclonal anti-CEA antibodies. When the cut-off value was set at 400 ng/ml so that the cases where measured values are not less than this value may be interpreted to be positive, the sensitivity and specificity were 60% and 75% respectively. The clear relationship was virtually observed between the concentration of CEA in nipple discharge and the cytological diagnosis. 9 of 10 malignant cases showed positive in both or either of the CEA assay and the cytological examination. And we could find 1 case of the zero stage of breast cancer and 4 cases in non-invasive carcinoma (Tis) through the combined diagnosis. On the other hand, only 2 of 8 benign cases showed false positive results. The correlation between the CEA concentration in nipple discharge and intratumoral expression of CEA was also observed. In this study, we concluded that the combined use of the enzyme immunoassay and the cytological examination would be more effective in the detection of early breast cancer accompanied with abnormal nipple discharge.

Adult↗
PubMed1991

Synaptic connections of a low-threshold mechanoreceptive primary neuron within the trigeminal subnucleus oralis.

The central axon of a primary afferent neuron that responded to indentation of the glabrous skin of the lower lip in a slowly adapting fashion was intra-axonally injected with horseradish peroxidase. The labeled terminal within the subnucleus oralis was examined electron microscopically. The labeled ending had a pale axoplasm and contained clear spherical synaptic vesicles. The labeled ending formed a synaptic triad with a dendrite and an unlabeled axonal ending with pleomorphic vesicles (a mixture of oval, flattened and dense core vesicles). The labeled primary ending was presynaptic only to the dendrite, while the unlabeled ending was presynaptic to both the dendrite and the labeled primary ending.

Animals↗
PubMed1991

Location of the motoneurons supplying the rabbit pharyngeal constrictor muscles and the peripheral course of their axons: a study using the retrograde HRP or fluorescent labeling technique.

The location of the motoneurons supplying the rabbit pharyngeal constrictor muscles (the superior and the middle constrictors, and the thyropharyngeus and the cricopharyngeus; the last two collectively compose the inferior constrictor) was investigated with intramuscular injection of HRP or the fluorescent tracer nuclear yellow into the individual muscles. Moreover, the peripheral course of their axons was investigated by injection of HRP into all of the pharyngeal constrictors in conjunction with intracranial severing of either the vagus or the glossopharyngeal nerves. The pharyngeal constrictor motoneurons were ipsilaterally located within a subdivision of the nucleus ambiguus which is formed by a compact arrangement of the smallest neurons of the nucleus and situated in the rostral half of the nucleus. We named that subdivision the compact cell group (CoG). Axons of the pharyngeal constrictor motoneurons traversed the vagal rootlets. The rostrocaudal extent of the pharyngeal constrictor motoneurons covered almost the entire length of CoG at a level from about 500 to 2,900 microns rostral to the obex, with their number being most numerous in the middle one-third level of the CoG. Although the motoneurons of the superior constrictor, those of the middle constrictor, and those of the thyropharyngeous and the cricopharyngeus overlapped considerably in location, they tended to be arranged rostrocaudally in that order. At the middle one-third level of the CoG, where the CoG is subdivided into dorsomedial and ventrolateral subgroups of neurons, the superior and the middle constrictor motoneurons were confined to the medial portion of the dorsomedial subgroup, while the inferior constrictor motoneurons were distributed throughout its entirety.

Animals↗
PubMed1991

Dynamic computed tomography for the evaluation of cerebrovascular disease.

Dynamic computed tomography (DCT) was evaluated as a diagnostic indicator for chronic supratentorial ischemia in 50 cases with or without minor neurological deficits. Peak height (PH, the maximum value of the gamma fitted curve), peak time (PT, the time to PH from the start of DCT), transit time (TT, the time between the first and second inflection points of the gamma fitted curve), and their functional maps were analyzed. Cerebral angiography was then performed in all cases to identify stenotic or occlusive vascular lesions in major cerebral arteries. DCT clearly detected 12 of 13 occlusions of the internal carotid artery (ICA) or middle cerebral artery (MCA), although one ICA occlusion was masked by the contralateral MCA occlusion. However, DCT detected only severe ICA or MCA stenosis (more than 90%). Probably, stenotic lesions of less than 90% did not cause detectable hemodynamic compromise. DCT using PH, PT, and TT functional maps is a useful diagnostic method for hemodynamic changes in ischemic cerebrovascular disease, although bilateral lesions and less stenotic lesions (less than 90%) are difficult to detect.

Adult↗
PubMed1991

Embolization of arteriovenous malformations with peripheral aneurysms using ethylene vinyl alcohol copolymer. Report of three cases.

The authors report three cases of arteriovenous malformations (AVM's) with aneurysms arising from the feeding artery; all were successfully treated with a new nonadhesive liquid embolic material, ethylene vinyl alcohol copolymer (EVAL). In two patients the AVM's were totally removed without difficulty, and in one the AVM was managed conservatively after embolization. No new neurological deficits appeared during or after embolization. After road-mapping techniques, EVAL was injected slowly until the feeding artery and aneurysm were completely obliterated. This embolic agent is easy to handle and is considered safe compared with other adhesive liquid embolic agents, such as isobutyl-2-cyanoacrylate or n-butyl cyanoacrylate. It is concluded that EVAL is an excellent agent for embolizing an AVM with a peripheral aneurysm on the feeding artery.

Adult↗
PubMed1990

Assessment of risk of carotid occlusion with balloon Matas testing and dynamic computed tomography.

Temporary occlusion of the internal carotid artery with a balloon catheter (balloon Matas test) and simultaneous dynamic computerized tomography scanning (DCT) were performed to determine the tolerance of permanent carotid occlusion in eight cerebral aneurysm and two carotid-cavernous fistula (CCF) cases, in whom internal carotid occlusion might be necessary during operation or as a choice of treatment. All patients were evaluated by mean transit time (MTT), especially % transit time (MTT of the occluded side x 100/MTT of the control side). In six patients, % transit time (%TT) was less than 155 and no neurological signs appeared after permanent internal carotid occlusion. Neurological deficit appeared when mean arterial blood pressure was 80, and disappeared when mean arterial blood pressure was 100 during the balloon Matas test in a case whose %TT was 200. Neurological deficit appeared several seconds after the balloon Matas test in a case whose %TT was 250. The critical %TT value to cause symptomatic ischaemia was 200 from our results. Therefore, it is necessary to undertake treatment such as bypass surgery for the patients whose %TT is near 200, even if the balloon Matas test was negative.

Aged↗
PubMed1990

Truncus solitarius pulmonalis.

The case of a female neonate with truncus solitarius pulmonalis (TSP), a rare congenital heart anomaly, is reported. She died four days after birth. A single right ventricle with common atrioventricular (AV) valve was associated with (Collet & Edwards type II) truncus arteriosus communis, and appeared to have a single coronary artery with an abnormally high take-off near the origin of the right subclavian artery. However, the vessel that appeared to be the single coronary artery was in fact an extremely hypoplastic ascending aorta associated with aortic atresia and agenesis of the left ventricle and mitral valve.

Coronary Vessel Anomalies↗
PubMed1990

Continuous wave Doppler echocardiographic evaluation of St. Jude prosthetic mitral valves in children.

The function of 9 St. Jude prosthetic mitral valves in 8 children was evaluated by continuous wave Doppler (CWD) echocardiography 28 +/- 22 months after implantation. All valves were apparently functioning normally on clinical examination. Peak flow velocity, mean flow velocity, pressure half-time and mean pressure gradient were determined from the transmitral flow velocity curve by CWD echocardiography. For comparison, the same parameters were examined in 15 normal children and 14 adults who had undergone mitral valve replacement. All measured values were greater in adults and children who had undergone valve replacement than in normal children. There were no differences in any parameter in adults or children in whom prostheses 25 mm or larger had been implanted. Although 3 children in whom prostheses 23 mm or smaller had been implanted had greater values for each parameter than those who received 25 mm or larger prostheses, there were no symptoms or signs of mitral stenosis. These data may be useful as guidelines for normal Doppler characteristics for St. Jude mitral valves in children. In an asymptomatic child whose prosthetic valve developed obstruction by granulation tissue overgrowth, each parameter significantly worsened as the heart rate increased. The changes in these parameters in 2 normally functioning St. Jude valves during atrial pacing were insignificant. The fluctuation of Doppler characteristics with changes in heart rate is useful for differentiating normally functioning prosthetic valves from impending stenosis.

Adolescent↗
PubMed1990

[Cervical spinal epidural abscess: case report].

Most cases of spinal epidural abscesses occur in a midthoracic or lower lumbar location. Cervical spinal epidural abscess is distinctly rare, and its prognosis is not favorable due to respiratory problems. We report a case of cervical spinal epidural abscess. A 77-year-old male was admitted because of tetraparesis and dyspnea. Two months before admission, he had been treated by femoro-femoral bypass for arteriosclerosis obliterans , and he had suffered from postoperative wound infection one month later. He had noticed neck pain two days before admission, followed by a numbness and motor weakness in both hands. Neurological examination showed flaccid tetraplegy with an absence of DTRs, paralysis of intercostal muscles, loss of sensation below the C4 dermatome, and bladder dysfunction. A spinal CT scan revealed a mass lesion in the anterior epidural space from C2 to C6, which displaced the spinal cord posteriorly. A myelogram showed complete blockage of contrast medium at the level of C7-T1. He was treated by emergency laminectomy of C3 to C6 with evacuation of the epidural abscess. Culture showed staphylococcus aureus, for which appropriate antibiotics were administered. In spite of such an intensive treatment, the patient showed poor neurological improvement and died 42 days after operation.

Abscess↗
PubMed1989

Neurons of origin of the internal ramus of the rabbit accessory nerve: localization in the dorsal nucleus of the vagus nerve and the nucleus retroambigualis.

The neurons of origin of the internal ramus of the rabbit accessory nerve were identified in the dorsal nucleus of the vagus nerve, using bilateral injections of horseradish peroxidase into the inferior vagal ganglion, soft palate, and pharynx, which were preceded by different combinations of the unilateral intracranial severings of the rootlets of the vagus and glossopharyngeal nerves, those of the cranial root of the accessory nerve, and the trunk of its spinal root. The neurons of origin occupied the caudal four-fifths of the dorsal vagal nucleus extending from about 1.0 mm rostral to the obex as far caudally as the second cervical spinal segment, with their number being about half the total number of neurons of the nucleus. Although considerably fewer, they were also located in the nucleus retroambigualis of the caudal half of the first cervical spinal segment and the second segment. Axons of most internal ramus neurons traversed the rootlets of the cranial accessory root. Axons of the few neurons located more caudally than about 1.0 mm caudal to the obex emerged from the upper cervical spinal cord to run along the trunk of the spinal accessory root before finally joining the internal ramus; caudal to the midlevel of the first cervical segment, the dorsal vagal nucleus and the nucleus retroambigualis contained neurons whose axons followed only that course.

Accessory Nerve↗
PubMed1989

Cystic arteriovenous malformation. A case report.

The authors report on a rare case of arteriovenous malformation (AVM) associated with cyst formation. Only five similar cases have been reported. CT findings of the cyst are divided into two types: 1) slit-like low density and 2) round one. Three patients showing slit-like cysts had experienced sudden severe headaches, probably due to haemorrhage. In contrast, two patients showing round cystic lesions had not experienced such sudden headaches and they revealed a nodule in the cyst at surgery. These facts suggest that there may be two different mechanisms for cyst formation in AVM's: haemorrhage and exudation. Slit-like cysts may result from old haemorrhage from the AVM nidus. Round cystic lesions may be due to exudation from the AVM nidus.

Adult↗