Search PubMed⌕ Search

Biomedical subjects

T Higashi

Publications and source records attributed to T Higashi.

At least 55 records · Page 3Linked to original sources
PubMed2001

[Bilateral carotid stenting for radiation-induced arterial stenosis].

We report a case of bilateral radiation-induced internal carotid artery (ICA) stenosis treated with stenting. A 67-year-old man experienced transient left hemiparesis several times, and it was diagnosed as a bilateral ICA stenosis by magnetic resonance angiogram (MRA) and cervical ultrasound sonogram (US). Ten years before, the patient had received radiation therapy (66 Gy) and radical resection for a squamous cell carcinoma (SCC) in the right infrapharyngeal space. A cerebral angiogram showed bilateral severe ICA stenosis (right; 90%, left; 99%). We diagnosed this as radiation-induced ICA stenosis, and performed carotid angioplasty with a self-expanding stent. The post-operative course was uneventful and the patient was discharged without neurological deficits. Carotid endarterectomy (CEA) is difficult in the case of carotid artery stenosis due to radiation-induced arterial injury. Carotid stenting may be an alternative treatment for such a patient.

Aged↗
PubMed2001

[A case of enucleation for multiple renal cell carcinomas in unilateral kidney with microwave tissue coagulator].

A 67-year-old man, who had undergone left nephroureterectomy for ureteral tumor (transitional cell carcinoma, G1) eight years previously, was found to have two renal tumors in the residual right kidney by the follow-up computed tomography (CT). We performed non-ischemic enucleation for multiple tumors at the upper and lower pole in the unilateral kidney using a microwave tissue coagulator (MTC). We confirmed by means of ultrasonography during operation the absence of any other satellite tumors. The operation time was 154 minutes and bleeding during operation was 267 ml. There was no difference between creatinine before (0.73 mg/dl) and after (0.79 mg/dl) operation. On the follow-up CT, there was a low density area after enucleation. This area gradually decreased and disappeared on enhanced CT 18 months after operation. We enucleated multiple renal cell carcinomas using MTC without reduction of renal function or remarkable side effects. These results suggested that non-ischemic enucleation using MTC would be useful for multiple renal cell carcinoma in the unilateral kidney.

Aged↗
PubMed2001

[Stenting for proximal subclavian and brachiocephalic artery occlusion--preliminary results].

The authors report the initial results, between January 1998 and February 2001, of stenting utilizing the brachial approach in seven patients for total occlusions at the following locations: two right subclavian, one brachiocephalic, and five left subclavian arteries. All lesions were associated with subclavian steal syndrome. Indications for the treatment included ischemic symptoms in the affected arm (seven patients), and vertebrobasilar insufficiency (five patients). A total of eight stents were implanted in six occluded arteries, resulting in a 75% procedural success rate. Procedural complications encountered were two subintimal dissections by a 0.035-inch guide wire during recanalization, and one stent dislodgement with migration. There was no stroke, presumably because of the previously reported preventive effect of delayed reversal of a stealing vertebral artery. Follow-up over a mean duration of 11 months revealed no sign or symptom of recurrence in cases with initial technical success. The results of the current study, with a literature survey, indicated that percutaneous transluminal angioplasty with primary stent deployment in an occluded prevertebral segment of the subclavian or the brachiocephalic artery should be considered as an available choice for treatment. Further points, such as some remaining technical and clinical problems, will require more experience and consideration.

Adult↗
PubMed2001

[Problems involved in endovascular embolization of intracranial aneurysms with three-dimensional Guglielmi detachable coils].

We experienced nine cases of intracranial aneurysms which were treated with three-dimensional Guglielmi detachable coils (3D-GDC). 3D-GDC is useful in the construction of the initial frame for the embolization of aneurysms, but it also has certain disadvantages for achieving successful treatment. Nine patients with nine intracranial aneurysms were treated with 3D-GDC for initial framing from October, 1999 to September, 2000 at the National Cardio-Vascular Center, Japan. Angiographically complete and successful occlusion was performed in only three patients. Four patients developed parent artery stenosis due to small loops of the 3D-GDC protruding from the aneurysm. Two patients experienced incomplete occlusion because small loops of the 3D-GDC caused cells to form in the framing, and additional coils could not be inserted into some cells. 3D-GDC is useful as an initial framing coil, but we should be careful when placing additional coils into an aneurysm because we cannot predict the effect of the small loops of 3D-GDC on the embolization of aneurysms.

Aged↗
PubMed2001

Actual invasive potential of human hepatocellular carcinoma revealed by in situ gelatin zymography.

BACKGROUND: The matrix-degrading proteinases are believed to play an important role in the invasion and metastasis of hepatocellular carcinoma (HCC), but no one has ever seen the in situ matrix-degrading activity in HCCs. PURPOSE: To demonstrate the cellular localization of actual gelatinolytic activity and to investigate the invasive potential of human HCC. EXPERIMENTAL DESIGN: HCC cases (30) were subjected to in situ gelatin zymography and SDS-gelatin gel zymogram. RESULTS: In situ gelatin zymography revealed a heterogeneous gelatinolytic activity in HCC cells, as well as stromal cells of noncancerous livers. The gelatinolytic intensity was stronger in 15 HCC nodules than in the corresponding noncancerous livers and was significantly associated with the cancer invasion to the capsule of the HCCs and to the portal veins. An intense gelatinolytic activity was detected in HCC cells in the front of tumor invasion. SDS-gelatin gel zymogram revealed gelatinases A and B that were mostly in latent forms. CONCLUSIONS: The present study demonstrates high gelatinolytic activity at the invasive front of HCCs at a cellular level and that HCC has an invasive potential with the gelatin (matrix)-degrading metalloproteinases. Furthermore, it suggests the importance of the activation mechanism of gelatinolytic enzymes in the invasion and metastasis of HCCs.

Carcinoma, Hepatocellular↗
PubMed2001

[Stenting for the occlusive carotid and subclavian arteries in Takayasu arteritis].

The authors report the initial results of stenting in four patients of Takayasu arteritis for 11 occlusive carotid and subclavian arteries between January 1999 and December 2000. The lesions included stenoses of two right subclavian, three right common carotid, two left common carotid, and two left subclavian arteries, and total occlusion of two subclavian arteries. A total of 14 stents were implanted in 10 arterial lesions, resulting in a 91% procedural success rate. One failure was due to inability to cross the total occlusion of the subclavian artery. Procedural complications and problems were pain during balloon angioplasty in three patients, vaso-vagal reflex in two, carotid artery perforation associated with transient horseness in one, and stent migration in one. There was no permanent morbidity. Follow-up over a mean duration of 12 months revealed one symptomatic recurrence of left subclavian stenosis, followed by a successful re-dilatation. The results of the current study indicated that primary stenting is an excellent therapeutic option for the occlusive carotid and subclavian arteries in Takayasu arteritis. A long-term follow-up is required to determine the response or behavior of stented segments of the affected arteries.

Adult↗
PubMed2001

[Mid-ventricular obstructive hypertrophic cardiomyopathy associated with an apical aneurysm and sustained ventricular tachycardia: a case report].

A 60-year-old woman presented with mid-ventricular obstructive hypertrophic cardiomyopathy associated with an apical aneurysm and sustained ventricular tachycardia. She was admitted because of drug refractory ventricular tachycardia. She had been treated with several antiarrhythmic agents, including amiodarone, but symptomatic episodes had continued. Echocardiography, magnetic resonance imaging, and left ventriculography showed mid-ventricular obstructive hypertrophic cardiomyopathy with an apical aneurysm. Electrophysiological study easily reproduced sustained pleomorphic ventricular tachycardia, polymorphic ventricular tachycardia, and ventricular fibrillation. The patient underwent implantation of a cardioverter-defibrillator. The relationship between mid-ventricular hypertrophic cardiomyopathy and apical aneurysm is unknown, but mid-ventricular hypertrophic cardiomyopathy is one of the causes of severe ventricular arrhythmias and sudden death.

Cardiomyopathy, Hypertrophic↗
PubMed2000

Delayed (18)F-fluoro-2-deoxy-D-glucose positron emission tomography scan for differentiation between malignant and benign lesions in the pancreas.

BACKGROUND: Positron emission tomography (PET) using (18)F-fluoro-2-deoxy-D-glucose (FDG) has been used for the evaluation of various tumors, but accumulation in inflammatory lesions makes it a controversial modality. The aim of this study was to investigate the usefulness of delayed scanning in differentiation between malignant and benign lesions in the pancreas. METHODS: Forty-seven patients with suspected pancreatic carcinoma were studied by FDG-PET. All patients received approximately 370 megabequerels of FDG after a transmission scan, and an emission scan was performed 1 hour and 2 hours later for all patients. A subset of 19 patients was also scanned at 3 hours postinjection. The standardized uptake value (SUV) was determined, and the retention index was calculated by dividing the increase in the SUV between 1 hour and 2 hours postinjection by the SUV at 1 hour postinjection. RESULTS: Of 27 malignant lesions, the SUVs of 22 lesions increased at 2 hours postinjection, whereas the FDG uptake in 17 of 20 benign lesions decreased. The SUVs at 3 hours postinjection were higher than those at 2 hours postinjection in 9 of 14 malignant lesions and in 2 of 5 benign lesions. Malignant lesions showed a higher retention index than benign lesions (mean +/- standard deviation: 12. 36 +/- 13.37 and -7.05 +/- 17.28, respectively; P < 0.0001). Applying an SUV of 2.5 at 1 hour postinjection with the cut-off value for the differentiation between malignant and benign lesions caused one false negative result and seven false positive results, with a diagnostic accuracy of 83.0% (39 of 47 patients). However, combining the retention index with the SUV obtained at 2 hours postinjection provided a higher diagnostic accuracy (91.5%; 43 or 47 patients) than the SUV alone. The false negative rate remained constant when the retention index was taken into account. Images at 3 hours postinjection usually were unhelpful in differentiating further between malignant lesions and benign lesions. CONCLUSIONS: The current data suggest that delayed FDG-PET scanning at 2 hours postinjection may contribute to differentiation between malignant and benign lesions in the pancreas.

Adult↗
PubMed2000

L-type Ca(2+) channel-mediated Zn(2+) toxicity and modulation by ZnT-1 in PC12 cells.

In view of evidence that Zn(2+) neurotoxicity contributes to some forms of pathological neuronal death, we developed a model of Zn(2+) neurotoxicity in a cell line amenable to genetic manipulations. Exposure to 500 microM ZnCl(2) for 15 min under depolarizing conditions resulted in modest levels of PC12 cell death, that was reduced by the L-type Ca(2+) channel antagonist, nimodipine, and increased by the L-type Ca(2+) channel opener, S(-)-Bay K 8644. At lower insult levels (200 micrometer Zn(2+)+Bay K 8644), Zn(2+)-induced death appeared apoptotic under electron microscopy and was sensitive to the caspase inhibitor benzyloxycarbonyl-Val-Ala-Asp-CH(2)F (Z-VAD); at higher insult levels (1000 microM+Bay K 8644), cells underwent necrosis insensitive to Z-VAD. To test the hypothesis that the plasma membrane transporter, ZnT-1, modulates Zn(2+) neurotoxicity, we generated stable PC12 cell lines overexpressing wild type or dominant negative forms of rat ZnT-1 (rZnT-1). Clones T9 and T23 overexpressing wild type rZnT-1 exhibited enhanced Zn(2+) efflux and reduced vulnerability to Zn(2+)-induced death compared to the parental line, whereas clones D5 and D16 expressing dominant negative rZnT-1 exhibited the opposite characteristics.

Animals↗
PubMed2000

Horizontal transmission of hepatitis B virus among players of an American football team.

Eleven cases of hepatitis B virus (HBV) infection (5 cases of acute hepatitis B and 6 of subclinical infection) were detected among 65 members of our university's American football team during a period of 19 months. All tested positive for antibody to the hepatitis B surface antigen (HB(s)Ag) or core antigen (HB(c)Ag). The incidence of HBV infection among team members (20.4%) was significantly higher (P<.001) than among students who tested positive for antibody to HB(s)Ag throughout the university (1.8%). We also detected a single carrier of hepatitis B e antigen (HB(e)Ag) on the team. Analysis of HB(s)Ag subtypes in 3 of 5 players with acute hepatitis B indicated that their subtype (adr) was identical to that of the HB(e)Ag carrier. All players with acute hepatitis B belonged to the same training group, which also included the HB(e)Ag carrier. Our analysis suggests that horizontal transmission of HBV can occur even in a sports team, probably due to contact with open wounds during training.

Acute Disease↗
PubMed2000

[Development and evaluation of the health management system including medical images].

In the field of occupational health management, there are many areas in which a number of X-ray films that are associated with health checkup data for longitudinal health management of high risk groups exposed to dusts and specific carcinogenetic chemicals can be used. To make comprehensive use of the medical checkup data, we examined and evaluated basic techniques in which medical images such as radiographs can be linked to the medical checkup data in a form of computer data. A three-step procedure system was developed based on the IS&C system which is a common specification of medical images: 1) data convert and barcode printing system, 2) film digitizing and database management system, 3) utilizing system of health checkup data including a medical image system. Experiments were done using the system and it was found that processing efficiency seemed to be less and/or varied depending on process types. It was also found that the extraction of data from existing systems and the storage methods of data onto a magnetooptical disk are special issues to be resolved in our system.

Diagnostic Imaging↗
PubMed2000

Fos induction in the brain of mice exhibiting behavioral abnormalities following administration of allylnitrile or crotononitrile.

Allylnitrile and crotononitrile induce behavioral abnormalities in mice. To explore the possible involvement of the vestibular system in these behavioral abnormalities, the expression of Fos protein, used as an indicator of neuronal activity, was examined within various brain structures in allylnitrile-, crotononitrile- and vehicle-treated mice. In each nitrile-treated mouse, Fos expression was observed in brain structures, which were divided into two groups. The structures in group 1 showed Fos expression between 1.5 h and 2 days postdosings, and in those in group 2 expression remained for up to 30 days postdosing. As most of these structures, especially in group 2, were identical to some Fos-positive structures observed after unilabyrinthectomy, the present results indicate that each nitrile induces Fos expression by causing a change in the peripheral vestibular system, resulting in behavioral abnormalities.

Animals↗
PubMed2000

Advantage of gene gun-mediated over intramuscular inoculation of plasmid DNA vaccine in reproducible induction of specific immune responses.

Utilizing a plasmid DNA encoding a single cytotoxic T lymphocyte (CTL) epitope and that encoding ovalbumin (OVA), we compared the reproducibility in the induction of immune responses by gene gun and intramuscular immunization. As compared to intramuscular inoculation, gene gun DNA immunization appeared to bring about highly reproducible and reliable results in the induction of specific CTL and IFN-gamma production to the CTL epitope and production of anti-OVA IgG. The results obtained by intramuscular inoculation vary significantly. Our data shown here strongly suggest that gene gun immunization of skin is a much more reliable method for DNA vaccination to induce effective immune responses in an animal model.

Animals↗
PubMed2000

Identification of epitopes for cross-reaction, auto-reaction and autoantibodies to catalase.

We identified in bovine and rat catalase two epitopes that were responsible for a cross-reaction between the two species using cross-reactive antibodies raised in rabbits by immunization with their respective catalases. The epitopes were(444)TFYLK(448)and(458)LCENIAGHLK(467)in bovine catalase and(445)TFYTK(449)and(459)LCENIANHLK(468)in rat catalase. The two epitopes in rats were also identified as epitopes for auto-reactive antibodies that were raised in rats by immunization with bovine catalase and were reactive with a homologous rat catalase. Furthermore, one of the rat epitopes,(459)LCENIANHLK(468), was identified as the epitope for autoantibodies which were inducible by intensive immunization in rats with the homologous rat catalase. A possible implication of the epitopes in certain human diseases is discussed.

Amino Acid Sequence↗
PubMed2000

FDG-PET of autoimmune-related pancreatitis: preliminary results.

The purpose of this retrospective study was to elucidate the fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) findings in autoimmune-related pancreatitis (AIP), which is a reversible chronic pancreatitis with an autoimmune cause. The study group comprised six patients with clinically diagnosed AIP. After 370 MBq (10 mCi) of FDG had been injected intravenously, the abdomen and/or the whole body was scanned at 1 h post injection in all patients, and scanning was repeated at 2 h in four patients. PET findings were evaluated visually and/or semiquantitatively using the standardized uptake value (SUV). In four of the six patients, PET demonstrated intense uptake in the whole pancreas, which appeared swollen on computed tomography, and the accumulation increased with time in three patients. In one patient, intense focal uptake in the pancreatic head was observed, and the accumulation decreased over time. In the remaining patient, no abnormal accumulation in the pancreas was observed. Follow-up PET scanning after steroid therapy was performed in three patients, and intense FDG uptake was no longer observed. Our preliminary data show that AIP can cause intense FDG uptake in the pancreas. This fact, and the benign status of the condition, should be kept in mind when making a diagnosis with FDG-PET in patients with pancreatic disorders.

Cell Survival↗
PubMed2000

Characterization of new conjugated metabolites in bile of rats administered 24,25-dihydroxyvitamin D(3) and 25-hydroxyvitamin D(3).

The characterization of new conjugated vitamin D metabolites in rat bile was performed using HPLC, liquid chromatography/tandem mass spectrometry combined derivatization, and GC-MS. After the administration of 24,25-dihydroxyvitamin D(3) to rats, 23, 25-dihydroxy-24-oxovitamin D(3) 23-glucuronide, 3-epi-24, 25-dihydroxyvitamin D(3) 24-glucuronide, and 24,25-dihydroxyvitamin D(3) 3-sulfate were obtained as new biliary metabolites together with 24,25-dihydroxyvitamin D(3) 3- and 24-glucuronides. The above metabolites, except 24,25-dihydroxyvitamin D(3) 3-glucuronide, were obtained from rats dosed with 25-hydroxyvitamin D(3). 23, 25-Dihydroxyvitamin D(3) 23-glucuronide was also obtained from the bile of rats administered 25-hydroxyvitamin D(3) in addition to its 3-glucuronide, 25-glucuronide, and 3-sulfate. Thus, it was found that 24,25-dihydroxyvitamin D(3) and 25-hydroxyvitamin D(3) were directly conjugated as glucuronide and sulfate, whereas at the C-23 position, they were hydroxylated and then conjugated. Furthermore, we found that the C-3 epimerization acts as one of the important pathways in vitamin D metabolism.

24,25-Dihydroxyvitamin D 3↗
PubMed2000

Expression of MAGE, GAGE and BAGE genes in human liver diseases: utility as molecular markers for hepatocellular carcinoma.

BACKGROUND/AIMS: The MAGE, GAGE and BAGE genes encode tumor antigens recognized by autologous cytotoxic T lymphocytes. The aim of this study was to evaluate the possibility of using these genes as molecular markers and as the targets of specific immunotherapy for human hepatocellular carcinoma (HCC). METHODS: The expressions of MAGE-1, MAGE-3, GAGE1-6, GAGE1-2 and BAGE mRNA in 33 surgically resected HCC samples and 26 of their corresponding non-cancerous samples (11 liver cirrhosis and 15 chronic hepatitis) were studied by a reverse-transcription polymerase chain reaction, and were compared with clinicopathological parameters. The expression of MAGE-1 was also examined in 16 biopsied HCC samples. RESULTS: MAGE-1, MAGE-3, GAGE1-6, GAGE1-2 and BAGE mRNA were expressed in 67%, 39%, 36%, 30%, and 21% of the HCC, respectively. At least one transcript was detected in 88% of the HCC, while no expression was observed in the non-cancerous livers. There was no significant correlation between the expression of any of the tumor antigens examined and the differentiation stage or size of the HCC. Especially, MAGE-1 was highly expressed in small HCC with a diameter of less than 2 cm and in well-differentiated HCC (81% and 70%, respectively), and was also expressed even in alpha-fetoprotein-negative and PIVKA-II-negative HCC (58% and 76%, respectively). The MAGE-1 expression was detected in 69% of biopsied HCC samples and the expression was high in both small and well-differentiated HCC. CONCLUSIONS: These tumor-specific antigens can be useful as molecular markers and as the possible target molecules for the specific immunotherapy of human HCC.

Adult↗