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Biomedical subjects

T Fuse

Publications and source records attributed to T Fuse.

At least 37 records · Page 2Linked to original sources
PubMed1998

Neurenteric cyst at the craniovertebral junction: report of two cases.

BACKGROUND: Neurenteric cysts are rare endothelium-lined structures. Two patients with symptomatic neurenteric cysts at the craniovertebral junction are presented. CASE PRESENTATION: Intermittent progression of neurologic symptoms delayed diagnosis for both patients. In one case, marked enlargement of the cyst was detected on serial imaging studies, and pathological examination of the excised lesion indicated rupture of the cyst. These cysts were totally resected by transoral or suboccipital approaches, as they were not firmly adherent to surrounding neural structures. The diagnosis of neurenteric cyst was confirmed by immunohistochemical analysis of the cyst wall. CONCLUSION: In view of the clinical course of these patients, we recommend early surgical resection of neurenteric cysts located at the craniovertebral junction.

Adult↗
PubMed1998

Multiple picrotoxinin effect on glycine channels in rat hippocampal neurons.

The effect of picrotoxinin on glycine-induced chloride currents was studied in dissociated rat hippocampal neuron culture in whole-cell and excised outside-out patches. Picrotoxinin blocked the glycine induced chloride currents. The picrotoxinin effect at 20 microM on glycine dose response relationship suggested a competitive mechanism. However, at 1 mM, the picrotoxinin effect was largely noncompetitive. In excised patches, glycine activated two types of channels distinguished by a difference in conductances. The first group had single channel conductances of around 47 pS and another around 100 pS. Occasionally, both types of channels were found in the same excised patch. Low concentration of picrotoxinin selectively blocked large conductance channels. At higher concentrations of 0.5 to 1 mM, picrotoxinin blocked the small conductance channels by a flickering block. These findings indicate that the whole-cell glycine current in rat hippocampal neurons is mediated by at least two types of channels. The two types of channels have distinct conductance, picrotoxinin sensitivity and different mechanism of picrotoxinin block.

Action Potentials↗
PubMed1998

Angiomyoma of the retropharyngeal space.

We encountered a 59-year-old man with angiomyoma of the retropharyngeal space. He had been referred to our hospital because of a six-month history of a sensation of a narrowed pharynx. A smooth-surfaced tumour arising from the posterior wall in the hypopharynx was observed by indirect laryngoscopy. Radiographical imaging revealed a solitary tumour with homogenous contents in the retropharyngeal space. The tumour was successfully removed via a lateral pharyngotomy approach under general anaesthesia. Histopathologically, the tumour was composed of numerous veins with thick muscular walls. To the best of our knowledge, this is the first report of an angiomyoma arising in the retropharyngeal space.

Angiomyoma↗
PubMed1998

Indirect glutamate neurotoxicity.

Indirect glutamate toxicity can be demonstrated by exposing dissociated rat hippocampal cultures to the media of the same culture transiently exposed (1 min) to glutamate (0.5 mM). The toxicity was maximum when the media was collected 5 min after the glutamate exposure. While the primary glutamate toxicity was attenuated by ionotropic glutamate receptor antagonists, the transferred, indirect toxicity was unaffected by the same antagonists. The changes in nuclear morphology indicated chromatin condensation and nuclear fragmentation in both primary and transferred toxicity. The stain for DNA damage by TUNEL method also revealed cells staining positive in both primary and transferred glutamate toxicity. These observations demonstrate that glutamate-induced neurotoxicity can be propagated to the uninjured cells by an unknown toxin released into the extracellular space. This neurotoxin induced both apoptosis and necrosis in cultured rat hippocampal cells.

6-Cyano-7-nitroquinoxaline-2,3-dione↗
PubMed1998

Heat-induced apoptosis in human glioblastoma cell line A172.

OBJECTIVE: Hyperthermia has been clinically applied to some types of brain tumors. However, the detailed mechanisms of this growth inhibition are not clear. The effect of mild hyperthermia on cultured human glioblastoma cell line, A172, was studied. METHODS: A172 cells were heat treated (43-44.5 degrees C) for 1 hour in the growing phase. Cell viability was assessed by trypan blue dye exclusion assay. The presence of apoptosis was determined by the morphological changes observed using phase contrast microscopy and nuclear changes observed using HOECHST 33342 stain. For the evaluation of cellular deoxyribonucleic acid fragmentation, the TUNEL method was used. The expression of p53 and bax proteins was evaluated by Western blot, and the bax messenger ribonucleic acid was detected by Northern blot. RESULTS: Heat treatment induced cell death in time- and temperature-dependent manners. The nuclear staining with HOECHST 33342 demonstrated morphological changes consistent with apoptosis. The TUNEL stain also demonstrated damages in the deoxyribonucleic acid. These morphological changes were accompanied by the accumulation of p53 protein, bax protein, and messenger ribonucleic acid. CONCLUSION: These results indicate that mild hyperthermia induces apoptosis in A172 glioblastoma cells.

Apoptosis↗
PubMed1997

Depolymerized holothurian glycosaminoglycan (DHG) prevents neointimal formation in balloon-injured rat carotid artery.

The in vivo activity of depolymerized holothurian glycosaminoglycan (DHG), a newly developed polysaccharide anticoagulant, on neointimal formation induced by a balloon catheter in the left common carotid artery of rats was investigated. In every Sprague-Dawley rat weighing approximately 400 g, a Forgaty 2Fr balloon catheter was inserted from the left femoral artery to the left common carotid artery, and was passed through three times in order to denude the endothelium of the artery. These rats were divided into four groups by the following treatment protocols; DHG was given to rats by daily subcutaneous injection into their abdomens at a dose of 3 mg/kg or 10 mg/kg (D3 or D10 group). For controls, 250 microl saline was injected daily (C group). Furthermore, 1 mg/kg of unfractionated heparin was also injected daily as a comparison to DHG (H group). Each treatment was performed in six rats, and the injections were continued for two weeks after the catheterization. The area ratio of thickened intima/media (I/M ratio) treated with DHG decreased in a dose-dependent manner compared to the control. In addition, the ratio in the D10 group was significantly lower than in the control (P < 0.01). However, the ratio in the H group did not decrease. By anti-a smooth muscle actin antibody staining the intimal thickening layers were seen to be completely occupied by proliferated smooth muscle cells, and their amount in these layers was attenuated by the DHG treatment. This indicated that DHG has an inhibitory effect on intimal thickening induced by balloon catheterization, and that this might be due to the inactivation of aberrant smooth muscle cells by this agent.

Angioplasty, Balloon, Coronary↗
PubMed1997

BAYw6228 suppresses accumulation of macrophages in balloon-induced intimal thickening of rabbit carotid artery.

To determine the in vivo activity of BAYw6228 (BAYw), a newly developed 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase inhibitor, we examined its effect on balloon catheterization-induced carotid arterial intimal thickening in Japanese white rabbits. In all rabbits weighing approximately 3.5 kg, a balloon catheter was inserted from a peripheral branch of the left external carotid artery to the aorta in order to denude the endothelium of the left common carotid artery. At day 12, they were divided into control and BAYw groups. The latter were subcutaneously injected with BAYw, 1 mg/kg/day, for the following 17 days. At day 15, the second balloon catheterization was performed in the same left common carotid artery in both groups. After another two weeks, the left common carotid artery was removed and stained with Elastica-Masson (EM) and anti-rabbit macrophage antibody (RAM 11). With RAM 11 staining, the number of positive cells in the intimal thickening was markedly decreased in the BAYw group compared with the control group (P < 0.01). Compared with the area ratio of the thickened intima/media layer of the control group, that of the BAYw group was significantly decreased to 45% (P < 0.05). These results indicate that BAYw prevents accumulation of macrophages and consequently contributes to the inhibition of intimal thickening induced by balloon catheterization.

Animals↗
PubMed1997

Determination of acid values of fats and oils by flow injection analysis with electrochemical detection.

A new method using a flow injection system with electrochemical detection was developed to determine acid values of fats and oils. VK3 (2-methyl-1,4-naphthoquinone) solution, i.e., ethanol containing 3 mM VK3 and 38 mM LiClO4, was used as the carrier solution. Flow signals were monitored at -0.33 V vs. Ag/AgCl. For preparation of a sample solution, an oil sample was completely dissolved in VK3 solution, or fatty acids were extracted from the sample into this solution. Aliquots (5 microliters) of the sample solution were injected into the flow injection system. Acid values were determined based on flow signals for 14 samples and the results were found to be consistent with those by potentiometric titration. Relative standard deviation was less than 2%. Samples were processed at the rate of 60 h-1. The stability of fish and cod liver oils was followed by measuring acid values for 8 weeks. This method proved to be a simple and rapid means for acid value determination.

Acids↗
PubMed1997

Magnetic resonance imaging in acute optic neuropathy by sphenoidal mucocele.

A 45-year-old man suffered sudden visual loss with Marcus-Gunn pupil and a central scotoma in the right eye as evaluated by visual field examination. The patient's right visual acuity was 0.02 (0.08 x -4.5 D). T1-weighted magnetic resonance imaging (MRI) demonstrated a cystic lesion of high intensity in the right sphenoid sinus. Short T1 inversion recovery (STIR) images presented a cystic lesion of high intensity in the right sphenoid sinus. In addition, a ring-shaped high intensity signal was seen surrounding the right optic nerve. Post-contrast fat suppression T1-weighted images did not demonstrate any enhancement within the right optic nerve. After intranasal sphenoidectomy, good recovery of the right visual acuity was noted. On subsequent MRI, the cystic lesion in the sphenoid sinus disappeared. Also, the ring of high intensity surrounding the right optic nerve became unclear. It was thought that the ring of hyperintensity seen on the STIR images demonstrated cerebrospinal fluid in the dilated perioptic subarachnoid space. Therefore, these MRI findings suggested that the acute visual loss resulted from a disturbed blood supply to the optic nerve due to compression by the sphenoidal mucocele, and not due to an inflammatory process.

Humans↗
PubMed1997

Suppression of neointimal thickening by a newly developed HMG-CoA reductase inhibitor, BAYw6228, and its inhibitory effect on vascular smooth muscle cell growth.

1. The aim of this study was to determine whether BAYw6228 (BAYw), a newly developed 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase inhibitor, could suppress an atherogenic process such as intimal thickening by a mechanism other than lowering the level of serum cholesterol. 2. First, we evaluated the in vitro effect of BAYw on the proliferation of vascular smooth muscle cells (SMC) from various species: Sprague-Dawley (SD) rats. New Zealand (NZ) white rabbits, intimal cells from Watanabe hereditary hyperlipidemic (WHHL) rabbit and SMC from the new-born human aorta. The increasing rate of total protein content of these cells was inhibited by the addition of BAYw in a dose-dependent fashion. In the presence of 2% foetal calf serum (FCS), the value of IC50 was 1.0 microM in SD rats, 2.1 microM in NZ white rabbits, and 0.3 microM in WHHL rabbits. With human SMC, the value was 0.02 microM in the presence of 10% FCS and 0.2 microM with a mixture of growth factors. 3. Based on these above in vitro findings, we next examined the in vivo effect of the agent to determine whether it could suppress rabbit intimal thickening induced by balloon catheterization. A balloon catheter was inserted from a peripheral branch of the left external carotid artery to the aorta to denude the endothelium of the left common carotid artery in Japanese white rabbits. After 12 days they were divided into control and BAYw groups. The former were subcutaneously injected with saline and the latter with BAYw 1 mg kg-1 day-1. Two days after the beginning of treatment, a second balloon injury was performed to the previously injured left common carotid artery in both groups. After another two weeks, the left common carotid artery was removed and variously stained. Although the total serum cholesterol in the BAYw group was significantly lower than in the control (P < 0.05), the difference was not enough to affect intimal thickening. In addition, the BAYw group had a smaller intima/media ratio than the control group, decreasing to 45% of control (P < 0.05). By anti-alpha smooth muscle actin antibody staining, these intimal thickening areas were entirely occupied by SMCs, and their amount was attenuated by BAYw. By anti-rabbit macrophage antibody (RAM 11) staining, the number of positive cells in the intimal thickening was markedly decreased in the BAYw group compared to control (P < 0.01). 4. These results indicate that BAYw has an inhibitory effect on intimal thickening by attenuating intimal SMC proliferation and infiltration of macrophages, suggesting that BAYw could be effective in the prevention of the progression of atherosclerotic plaque-like restenosis after angioplasty.

Animals↗
PubMed1997

Clinical observation of 14 cases of childhood polyarteritis nodosa in Japan.

An epidemiological survey of childhood polyarteritis nodosa was conducted at 1290 hospitals followed by a secondary survey of hospitals that had therapeutic experience with the disease. Fourteen cases obtained from these surveys were studied clinically. The male-female ratio was 4:3. The mean age at onset was 10.6 years. To established the diagnosis, skin biopsy was performed in 43%, retrograde aortography in 21%, and kidney biopsy in 14% of cases. Non-specific symptoms such as fever (86%), skin eruption (50%), arthritis (50%), myalgia (50%), abdominal pain (43%) and hypertension (36%) were often noted as clinical findings at the initial visit. Throughout the clinical course, symptoms considered to be caused by local angiopathy, including interrupted blood circulation, were frequently noted. On blood tests, no specific findings other than acute inflammatory reaction were observed. Steroid preparations were used for treatment in all cases but one, and about half of them are presently free from steroids. Immunosuppressants were administered in 10 cases. As for prognosis, all patients are alive, but untoward sequelae were noted in 36% of cases. The results of the present survey reinforced the difficulty of establishing a final differential diagnosis because specific findings were scarce for this disease, as stated in previous reports. Establishing a method for early diagnosis by gathering and analyzing more data in detail will be necessary in the future.

Child↗
PubMed1997

Aortitis syndrome in children: clinical observation of 35 cases in Japan.

The results of clinical observation of 35 patients with aortitis syndrome (AS) in childhood, obtained by a nationwide survey in Japan, are reported. The male to female ratio was 1:2.5, the estimated age of onset averaged 10.2 years, and the duration from the estimated age of onset to the diagnosis averaged 15 months. In HLA examination A24, Bw52, Cw7 and DR2 were relatively common. Arterial lesions tended to extensively involve the aortic arch and its branches. Fever was the most frequently noted clinical symptom, followed by abdomen, joint and muscle pain. The physical findings in order of frequency were impaired circulation of the upper extremities, cardiac and vascular murmurs, hypertension, impaired cerebral circulation, visual disorder and impaired circulation of the pulmonary artery. The murmurs were found not only over the chest wall but also over the cervical area and abdomen. Pulselessness of the upper extremities occurred in 66% of patients. Percutaneous retrograde aortography and/or intravenous digital subtraction angiography to make the final diagnosis was employed except for three cases. There were not any specific abnormal signs in laboratory data. Steroid hormones were administered in 34 cases, and immunosuppressive agents in 8 cases. Five cases had percutaneous transluminal angioplasty to the right renal artery as an interventional treatment. The high frequency of abdominal pain is considered to be one of the characteristics of AS in childhood. The high frequency of pulselessness of the upper extremities and cardiac and vascular murmurs in this report is considered significant for the diagnosis of AS in childhood.

Aortitis↗
PubMed1997

Arterial dissection of the vertebrobasilar systems: a possible cause of acute sensorineural hearing loss.

OBJECTIVE: Our goal was to describe three cases of acute sensorineural hearing loss (ASNHL) that might be caused by arterial dissection of the vertebrobasilar system. DESIGN: Retrospective case review. SETTING: Yamagata University Hospital, Yamagata, Japan. PATIENTS: Thirty-seven patients with ASNHL underwent magnetic resonance (MR) imaging between September 1993 and March 1995. INTERVENTIONS: Proton density and T2-weighted axial images and three-dimensional spoiled gradient-recalled acquisition in steady state (3-D SPGR) imaging with gadopentetate dimeglumine were obtained with a 1.5 T MR system in all patients. T1-weighted images were obtained in 23 patients. Vertebral angiography (VAG) was performed in 4 of the 37 patients. RESULTS: In 3 of the 37 patients, the presence of vertebrobasilar dissection was confirmed: contrast-enhanced 3-D SPGR images disclosed double lumen of the proximal basilar artery and/or the ipsilateral vertebral artery in all of the 3 patients. In two of them, the vertebrobasilar dissection was also confirmed by VAG. The hearing loss of all three patients improved after the onset. Audiograms revealed no characteristic pattern of the initial hearing loss among them. CONCLUSIONS: Vertebrobasilar dissection may cause an intramural hematoma involving the orifice of the anterior inferior cerebellar artery or a distal thromboembolism reducing the blood flow of the labyrinthine artery; these conditions can lead to onset of hearing loss. Arterial dissection of the vertebrobasilar system might be one of the causes of ASNHL.

Adolescent↗
PubMed1996

Heat shock-mediated cell cycle arrest is accompanied by induction of p21 CKI.

Heat shock induces several events in cells including a series of gene expressions and cell cycle arrest. Recently, several types of cell cycle arrest have been related to the function of cyclin-dependent kinase inhibitors (CKI). Here we show that heat shock treatment up-regulates p21 CKI mRNA and protein in A172 glioma cells and arrests the cell cycle at the G1 phase, p53-deficient cell lines, MDAH041 and T98G, also showed a significant increase in p21 CKI expression after heat stress, indicating that the induction involves a p53-independent pathway. The kinetics of this transient induction, which is not affected by cycloheximide, demonstrate that p21 CKI is an immediate-early response gene.

Cell Cycle↗
PubMed1996

Quantitative analysis of sound localization with ocular positioning.

We studied the capacity for sound localization in the horizontal plane with measurement of the ocular position of the listener. The eye position responses elicited by tonal sound were asymmetrical in all six subjects and there was individual variation of frequency dependence. The sound pressure level and the angle of the loudspeaker also affected the accuracy of localization. Sound localization was more accurate, and individual variation lower, when the sound pressure level and the angle of the sound source were in the range 50 dBSL and 30 degrees, respectively. In the monoaural condition, the ear on the occluded side consistently showed displacement of responses toward the side of the non-occluded ear. Sound localization on the non-occluded side, however, showed various patterns of change in the monaural condition relative to the binaural condition. Cues as to the sound localization thus seem to differ with the side of the sound source.

Acoustic Stimulation↗
PubMed1996

Arteriovenous malformation associated with moyamoya disease.

The first case of a child with an arteriovenous malformation (AVM) associated with moyamoya disease is reported. The patient presented ischemic symptoms and underwent indirect bypass surgery on both sides when she was 5 years old. Four years later she suffered from headache, and a small AVM of the left frontal lobe associated with the moyamoya vessels was detected. Single photon emission computed tomography (SPECT) was performed at age 11 and demonstrated low local cerebral blood flow (CBF) in the left frontal lobe and right temporal lobe, although the revascularization after the bypass surgery seemed to be effective, as judged on pancerebral angiography. We feel that brain ischemia due to the moyamoya disease may have played a causative role in the development of the AVM.

Blood Flow Velocity↗
PubMed1996

Systemic multiple aneurysms of the intracranial arteries and visceral arteries: case report.

BACKGROUND: Systemic multiple aneurysms are rare, and an association between intracranial aneurysms and visceral aneurysms is an extremely rare occurrence. CASE PRESENTATION: This 56-year-old woman was referred to our hospital with subarachnoid hemorrhage. Physical examination revealed no particular morphologic features suggesting connective tissue diseases. Cerebral angiography demonstrated two aneurysms of the left internal carotid artery and the right middle cerebral artery. The internal carotid artery aneurysm was occluded surgically. Four days later, she had right hemiparesis and mild aphasia due to cerebral vasospasm. While she was started on hemodynamic therapy and the administration of thromboxane A2 synthetase inhibitor for cerebral vasospasm, she suffered intraabdominal hemorrhage due to the rupture of the visceral artery aneurysms, and was treated with emergency surgery. CONCLUSION: The hemodynamic therapy and the administration of thromboxane A2 synthetase inhibitor for symptomatic vasospasm may have precipitated the rupture of the intraabdominal aneurysm.

Aneurysm↗