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Biomedical subjects

K Tabuchi

Publications and source records attributed to K Tabuchi.

At least 73 records · Page 4Linked to original sources
PubMed1999

[Indication and outcome in emergent coronary artery bypass graft for acute coronary syndrome].

Among 462 cases receiving coronary artery bypass graft (CABG) during the period from November 1991 to January 1999, emergency operation was performed within 24 hours for 27 cases. Male-to-female ratio was 21:6, and age of patients ranged from 50 to 83 years (average age: 65.9 years). Intra aortic balloon pumping (IABP) was used from preoperative period for 25 cases, and PCPS was used for one case. Operation was performed under cardiac arrest in 25 cases and under ventricular fibrillation in 2. Average number of grafts was 2.4 +/- 1.0 and perioperative mortality was 25.9%. The results of emergency cases were extremely low compared with mortality of palliative operation of 3.4%, whereas mortality has been improved to 12.5% (2/16) in the last two years. These results suggest that it is important for the improvement of the outcome in emergency CABG to prevent aggravation of circulatory dynamics and to shift to operation under stable conditions.

Aged↗
PubMed1998

A novel Drosophila paired-like homeobox gene related to Caenorhabditis elegans unc-4 is expressed in subsets of postmitotic neurons and epidermal cells.

We have isolated a novel Drosophila paired-like homeobox gene, DPHD-1. The homeodomain of DPHD-1 showed 85% amino-acid identity with that of the C. elegans Unc-4 protein. Whole-mount in situ hybridization of embryos and third-instar larvae revealed that the DPHD-1 mRNA is specifically localized in subsets of postmitotic neurons in the central nervous system (CNS) and in the developing epidermis with a segmentally repeated pattern. Double staining with a posterior compartment marker, an anti-Engrailed antibody, showed that DPHD-1 expressing neurons in the CNS were present in the posterior compartment, whereas DPHD-1 expression in the epidermis was restricted to the anterior compartment in each segment. This temporal and spatial expression pattern suggests that DPHD-1 may play a role in determining the distinct cell types in each segment.

Amino Acid Sequence↗
PubMed1998

Localization of 5-HT2A receptor in rat cerebral cortex and olfactory system revealed by immunohistochemistry using two antibodies raised in rabbit and chicken.

Serotonin 2A receptor (5-HT2A receptor) is widely distributed in the central nervous system, and has been suggested to be involved in a variety of behavioral conditions and neuropsychiatric disorders. Two polyclonal antibodies were raised against the N-terminus peptide of rat 5-HT2A receptor in chickens (5-HT2A-N) and a glutathione S-transferase fusion protein that contained the C-terminus of the mouse 5-HT2A receptor in rabbits (5-HT2A-C). Affinity-purified 5-HT2A-N and -C antibodies reacted strongly with a single band of 77-78 kDa in postsynaptic density proteins prepared from the rat cortex. The distribution pattern of immunoreactive structures in the rat brain was virtually the same for the two antibodies. The highest levels of immunoreactivity were observed in the olfactory bulb, neocortex, claustrum, piriform cortex, mamillary bodies, pontine nuclei, red nucleus and cranial motor nuclei. In the olfactory bulb, mitral cells were intensely labeled. In the neocortex, many immunoreactive neurons were found in layers II-VI. In layer IV of the neocortex, strong neuropil labeling was observed. In a double-labeling study using chicken 5-HT2A-N and rabbit anti-glial fibrillary acidic protein (GFAP) antibody, a considerable number of GFAP positive cells also showed 5-HT2A immunoreactivity. By using an immunoelectron microscopic technique, 5-HT2A receptor immunoreaction was shown to be localized just beneath the postsynaptic membrane thickening of asymmetric synapses.

Amino Acid Sequence↗
PubMed1998

The effect of mannitol upon cochlear dysfunction induced by transient local anoxia.

Transient local anoxia of the cochlea was induced by pressing the labyrinthine artery, and compound action potential (CAP) or endocochlear potential (EP) was measured before and after transient local anoxia ranging from 5 to 60 min using 106 albino guinea pigs. The complete interruption of the cochlear blood flow by this procedure and its full restoration after releasing the pressure on the artery was confirmed by a laser-Doppler flowmeter. The anoxia of less than 10 min induced no post-anoxic cochlear dysfunction, whereas the anoxia of a longer duration induced an irreversible dysfunction of the cochlea. It was evident that the post-anoxic recovery of the CAP threshold was worse as the anoxia period was prolonged, and CAP was almost completely abolished after 60-min anoxia. In animals which were administered mannitol intravenously just after the restoration of the cochlear blood circulation, the recovery of the CAP threshold was significantly better than that in the control animals, when the animals were subjected to local anoxia of 15- to 30-min duration. No beneficial effect, however, was observed in the 60-min anoxia group. In conclusion, local anoxia of 10 min or longer caused cochlear dysfunction, which was partially but significantly alleviated by mannitol.

Action Potentials↗
PubMed1998

Model-based surgical planning and simulation of cranial base surgery.

Plastic skull models of seven individual patients were fabricated by stereolithography from three-dimensional data based on computed tomography bone images. Skull models were utilized for neurosurgical planning and simulation in the seven patients with cranial base lesions that were difficult to remove. Surgical approaches and areas of craniotomy were evaluated using the fabricated skull models. In preoperative simulations, hand-made models of the tumors, major vessels and nerves were placed in the skull models. Step-by-step simulation of surgical procedures was performed using actual surgical tools. The advantages of using skull models to plan and simulate cranial base surgery include a better understanding of anatomic relationships, preoperative evaluation of the proposed procedure, increased understanding by the patient and family, and improved educational experiences for residents and other medical staff. The disadvantages of using skull models include the time and cost of making the models. The skull models provide a more realistic tool that is easier to handle than computer-graphic images. Surgical simulation using models facilitates difficult cranial base surgery and may help reduce surgical complications.

Adult↗
PubMed1998

Combination therapy of fasudil hydrochloride and ozagrel sodium for cerebral vasospasm following aneurysmal subarachnoid hemorrhage.

Fasudil hydrochloride is a new type of intracellular calcium antagonist, different from the calcium entry blockers that are commonly employed for clinical use. Since September 1995, the combination of fasudil hydrochloride and ozagrel sodium, an inhibitor of thromboxane A2 synthesis, has been used to treat 60 patients at risk of cerebral vasospasm after aneurysmal subarachnoid hemorrhage. The effectiveness of this combination therapy was investigated by comparison with the outcome of 57 patients previously treated with only ozagrel sodium. The combination therapy was significantly more effective (p < 0.01) in reducing the incidence of low density areas on computed tomography scans, and reduced, but not significantly, the occurrence of symptomatic vasospasm. The combination therapy of fasudil hydrochloride and ozagrel sodium has superior effectiveness over only ozagrel sodium in treating patients at risk of vasospasm after aneurysmal subarachnoid hemorrhage.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1998

Blood blisterlike aneurysms of the internal carotid artery.

OBJECT: An aneurysm arising from the anterior wall of the internal carotid artery (ICA) is a poorly understood entity. A small hemispherical bulge from the anterior wall of the ICA, which is called a "blood blisterlike aneurysm" (BBA), may be confused with a tiny berry aneurysm although the clinical features are distinctly different. This paper summarizes the clinical course of patients with this lesion to clarify the nature of the BBA. METHODS: Six patients with BBAs who presented with subarachnoid hemorrhage (SAH) are described. In all patients, the initial angiogram obtained soon after SAH showed only a small bulge from the anterior wall of the ICA. In three of the six patients this bulge had progressed to a saccular appearance within a few weeks. The wall of the lesion was so thin and fragile that the aneurysm ruptured at the base during clipping or within a few hours after clipping in two patients. CONCLUSIONS: From the authors' experience, as well as a review of the literature, which includes an autopsy study of similar cases, it is inferred that these lesions are focal wall defects covered only with thin fibrous tissue and that they are therefore not true aneurysms. Direct clipping often causes laceration of the lesion, whereas complete wrapping or clipping after wrapping is effective, but may fail to prevent growth of the aneurysm. Endovascular occlusion of the cervical ICA with or without bypass surgery, which is less risky than direct surgery, is another option.

Adult↗
PubMed1998

[Clinical usefulness of scatter and attenuation correction for brain single photon emission computed tomography (SPECT) in pediatrics].

This investigation was undertaken to study clinical usefulness of scatter and attenuation correction (SAC) of brain SPECT in infants to compare the standard reconstruction (STD). The brain SPECT was performed in 31 patients with 19 epilepsy, 5 cerebro-vascular disease, 2 brain tumor, 3 meningitis, 1 hydrocephalus and psychosis (mean age 5.0 +/- 4.9 years old). Many patients was necessary to be injected sedatives for restraining body motion after Technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO) was injected at the convulsion or rest. Brain SPECT data were acquired with triple detector gamma camera (GCA-9300 Toshiba Japan). These data were reconstructed by filtered backprojection after the raw data were corrected by triple energy windows method of scatter correction and Chang filtered method of attenuation correction. The same data was reconstructed by filtered backprojection without these corrections. Both SAC and STD SPECT images were analyzed by the visual interpretation. The uptake ratio of cerebral basal nuclei was calculated by the counts of the thalamus or lenticular nuclei divided by the cortex. All images of SAC method were excellent than that of STD method. The thalamic uptake ratio in SAC method was higher than that of STD method (1.22 +/- 0.09 > 0.87 +/- 0.22 p < 0.01). The lenticular nuclear uptake ratio in SAC method was higher than that of STD method (1.26 +/- 0.15 > 1.02 +/- 0.16 p < 0.01). Transmission scan is the most suitable method of absorption correction. But the transmission scan is not adequate for examination of children, because this scan needs a lot of time and the infants are exposed by the line source radioisotope. It was concluded that these scatter and absorption corrections were most suitable method for brain SPECT in pediatrics.

Adolescent↗
PubMed1998

Magnetic resonance imaging of the shoulder in abduction.

To simulate the painful arm position in subacromial impingement syndrome, magnetic resonance imaging of the shoulder was done with the arms at the sides and at 80 degrees abduction in two groups of patients. Group A had 20 shoulders in 20 patients with subacromial impingement syndrome and Group B had 19 shoulders in 19 patients without impingement syndrome. When arm position was changed from adduction to abduction, an increase in signal intensity of the rotator cuff tendon was seen more often in Group A (45%) than in Group B (26%). Group A shoulders showed encroachment of the acromion or the acromioclavicular joint to the rotator cuff in 25% of the shoulders with the arms at the sides, and in 75% with the arms in abduction. Similar findings were observed in only 14% and 21% of Group B shoulders in the respective arm positions. Abduction of the arms seemed to cause encroachment of the overlying structure, especially of the acromioclavicular joint, to the rotator cuff in patients with subacromial impingement syndrome, even if there were no such findings in the images with the arms at the sides.

Acromioclavicular Joint↗
PubMed1997

Differential display cloning of a novel rat cDNA (RNB6) that shows high expression in the neonatal brain revealed a member of Ena/VASP family.

We have used the differential display method to identify genes that control the neural cell development in CNS. Screening of the differential display bands that showed higher expression at neonate than at adult age enabled us to identify a novel rat cDNA (RNB6) coding for a protein of 393 amino acid residues. Database search revealed this gene as a rat homologue of the murine EVL, a member of Ena/VASP protein family that is implicated to be involved in the control of cell motility through actin filament assembly by their GP5 motifs. Although the precise characterization of EVL was not reported, our Northern blot and immunoblot analyses demonstrated that RNB6 expression in the brain gradually increases during embryonic development, reaches maximum at postnatal day 1 and decreases thereafter. Studies of tissue distribution revealed the expression of RNB6 not only in the brain but also in the spleen, thymus and testis. Histochemical analyses showed that RNB6 protein is mainly expressed in neurons and may be expressed in neural fibers. Our analyses suggest that RNB6 is critically involved in the development of CNS probably through the control of neural cell motility and/or including neuronal fiber extension.

Amino Acid Sequence↗
PubMed1997

[True "PICA communicating artery" aneurysm: a case report].

We present an unusual case of an aneurysm of the distal posterior inferior cerebellar artery (PICA). A 51-year-old female presented a subarachnoid hemorrhage with mild consciousness disturbance on August 6, 1992. Computed tomography (CT) on admission showed subarachnoid hemorrhage with thick hematoma in the cisterna magna and intraventricular hematoma in the 4th, 3rd and both lateral ventricles. The angiogram on admission revealed no definite vascular anomalies. Repeated angiograms on the 11th day after onset showed an aneurysm on anastomotic branch between the bilateral distal PICAs. The aneurysm was clipped successfully through a suboccipital craniectomy 14 days after the onset. In the literature reviewed, only one such aneurysm, located at an anastomotic vessel of the bilateral PICAs, has been reported by Hlavin et al in 1991. They reported that the aneurysm was associated with a unilateral PICA that supplied both cerebellar hemispheres and arose from an anastomotic vessel in the contralateral circulation. They called the aneurysm as "a PICA communicating artery" aneurysm. We assume that this "PICA communicating artery" is a remnant of a primitive lateral vertebrobasilar anastomosis, which appears in the embryo at the 9 mm stage. It is suggested that the pathogenesis may be not only the hemodynamic factor but also a congenital anomaly.

Arterio-Arterial Fistula↗
PubMed1997

[Usefulness of 99mTc-tetrofosmin myocardial scintigraphy before and after coronary intervention].

Dipyridamole-loading 99mTc-tetrofosmin myocardial scintigraphy was performed for patients with coronary artery disease who underwent percutaneous transluminal coronary angioplasty (PTCA) in order to examine whether SPECT imaging prior to treatment is useful for the determination of prognosis after coronary intervention. Thirty-six patients including 9 with angina pectoris (AP), 22 with old myocardial infarction (OMI) and 5 OMI with AP were underwent dipyridamole-loading 99mTc-tetrofosmin myocardial SPECT before and after coronary intervention. The length of follow-up was 185 +/- 107 days after PTCA. Improvement of myocardial uptake was observed on myocardial SPECT in all cases with AP. Improvement of the myocardial uptake was observed 50% (4/8) of patients with OMI who had no myocardial viability. It was suggested that the improvement of myocardial uptake after PTCA was due to incomplete fill-in in cases with AP and that the presence of fill-in was important for level of fill-in in patients with AP. The improvement of myocardial uptake in the scar tissue in patients with OMI contributed to the hibernating myocardium. We concluded that correct detection of hibernating myocardium was difficult despite the superior imaging capability of 99mTc-tetrofosmin myocardial SPECT.

Aged↗
PubMed1997

[A case of aortic valve replacement 3 years after coronary artery bypass grafting].

A rare case of aortic valve replacement (AVR) with poor left ventricular function, following coronary artery bypass grafting, was reported. The patient was 57-year-old man who received urgent CABG with 2 saphenous vein grafts 3 years ago. At that time, aortic regurgitation (AR) was grade 2. He suffered acute myocardial infarction 1 year after CABG because of the occlusion the saphenous vein graft to the obtuse marginal branch. Percutaneous transluminal angioplasty was successfully performed for occluded graft. Since then, however, AR increased gradually and the left ventricular function decreased. Three years after the initial operation, he was admitted again with congestive heart failure. Heart catheterization revealed grade 3 AR and 17% left ventricular ejection faction (LVEF). AVR was performed through a median sternotomy and 2 saphenous vein grafts were preserved. He showed uneventful postoperative recovery and is now very well with 40% LVEF.

Angina, Unstable↗
PubMed1997

[Histological findings in aneurysm treated with IDC: scanning electron microscopical study].

We reported the scanning electron microscopic findings of an aneurysm embolized with interlocking detachable coils (IDC). A 78-year-old man was referred to our hospital because of left hemiparesis and dysphagia. CT scan showed multiple lacunar infarction in the bilateral corona radiata. Angiography demonstrated a small incidental aneurysm of the right internal carotid artery (IC-PC junction). The left hemiparesis gradually improved and 2 weeks after admission the aneurysm was treated with IDC. Three coils were placed in the aneurysm and post-operative angiography demonstrated complete embolization. Dysphagia caused by the pseudobulbar pulse did not improve and, 4 weeks after endovascular surgery, the patient died of aspiration pneumonia. An autopsy was performed and the scanning electron microscopical findings of the aneurysm showed development of endothelial cells on the coil surface. Many clinical reports supported the usefulness of Guglielmi detachable coils (GDC) and several experimental reports demonstrated the intimal proliferation in aneurysms embolized with coils. However, pathological changes of the aneurysms treated with coils have been reported in only four clinical cases. There was no evidence of endothelialization in any of these cases. To our knowledge, our case is the first report describing the endothelial proliferation over the coils. It is necessary to accumulate histopathological data and long-term follow-up in humans treated with coils.

Aged↗
PubMed1996

Detection of feline herpesvirus 1 DNA by the nested polymerase chain reaction.

The thymidine kinase region of feline herpesvirus 1 (FHV 1) genome in ocular/nasal swabs from cats with clinical manifestations of upper respiratory disease was amplified by nested polymerase chain reaction (nested PCR). Two primer pairs were prepared for nested PCR. FHV 1 DNA in ocular/nasal swabs was extracted using instaGene-DNA purification matrix. Nested PCR for the FHV 1 culture supernatants was ten times as sensitive as single PCR. On comparing viral isolation with single PCR and nested PCR for the detection of FHV 1 in ocular/nasal secretions, of 5 samples that yielded infectious virus in cell culture, 3 (60%) were positive in single PCR and 5 (100%) were positive in nested PCR. When 22 ocular/nasal swabs that did not yield FHV 1 were assayed, 3 were negative in both single PCR and nested PCR, 2 were positive in both single and nested PCR and 17 were positive in only nested PCR. Thus, FHV 1 was detected in 19/22 (86.4%) by the nested PCR and in 2/22 (9%) by single PCR. These results show that nested PCR is 4.8 (24 positive samples/5 positive samples) times as sensitive as single PCR.

Animals↗