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Biomedical subjects

Y Hirose

Publications and source records attributed to Y Hirose.

At least 109 records · Page 6Linked to original sources
PubMed1998

Clinical importance of c-Met protein expression in high grade astrocytic tumors.

The clinical importance of the expression of c-Met protein, the receptor of hepatocyte growth factor/scatter factor, was evaluated in neuroepithelial tissue tumors. c-Met immunohistochemistry was performed using the streptavidin-biotin-peroxidase complex method with anti-c-Met polyclonal antibody. Specimens were classified as c-Met negative (< 30%) or c-Met positive (> or = 30%) according to the proportion of immunopositive cells under microscopic examination. All c-Met-positive cases occurred in high grade astrocytic tumors, not in other neuroepithelial tissue tumors. Most c-Met-positive astrocytic tumors were classified histologically as high grade tumors. Epidermal growth factor-receptor (EGFR) and MIB-1 immunohistochemistry were also performed for high grade astrocytic tumors. Survival analysis was performed for patients with these tumors with variables including c-Met positivity, EGFR positivity, and MIB-1 labeling index. Positivity of c-Met was independent from EGFR positivity and MIB-1 labeling index, and the c-Met-positive group showed a significant shorter survival (p < 0.05). c-Met immunopositivity may be a parameter of biological aggressiveness in high grade astrocytic tumors. Examination of c-Met expression in astrocytic tumors provides significant clinical information, especially as a prognostic factor.

Astrocytoma↗
PubMed1998

Secondary glioblastoma remarkably reduced by steroid administration after anaplastic transformation from gliomatosis cerebri--case report.

A 45-year-old female presented with gliomatosis cerebri manifesting as hemiballismus-like involuntary movement in the arm, motor weakness in the leg, and hypesthesia in her left side. Computed tomography showed only diffuse swelling of the right cerebral hemisphere, but T2-weighted magnetic resonance imaging revealed a diffuse lesion spreading from the right thalamus to the temporal, parietal, and occipital lobes on the same side. No abnormal enhancement was recognized. Cerebral angiography showed no specific finding. A right occipital lobectomy was performed to confirm the diagnosis of gliomatosis cerebri. Anaplastic transformation was recognized 5 months later. The disease did not resolve with radiation or interferon administration, but steroid therapy achieved remarkably effective tumor regression. The patient died due to pneumonia. Autopsy showed the features of diffuse glioblastoma. Steroid therapy may be an effective treatment for gliomatosis cerebri before the terminal stage.

Astrocytoma↗
PubMed1998

Access control and system audit based on "patient-doctor relation and clinical situation" model.

Both confidentiality of privacy and the data sharing between healthcare practitioners are required in hospital information systems. A new access control method has been designed by the "patient-doctor relation and clinical situation at the point-of-care" model in addition to the traditional "account and password" mechanism. This method can; (I) allow flexible data access in need, (2) afford accurate access audit, (3) suppress inappropriate access.

Computer Security↗
PubMed1998

Combined thallium-201 myocardial with technetium-99m-HMPAO brain SPECT: myocardial ischemia induced by acetazolamide in severe coronary artery disease.

Since the perioperative mortality of coronary artery bypass surgery is high in patients with cerebrovascular disease, it is crucial to assess a cerebrovascular risk before operation. Acetazolamide (ACZ) was applied to brain SPECT to evaluate the vascular reserve, and ACZ stress brain imaging was useful for predicting perioperative cerebrovascular events. We performed 201Tl myocardial and 99mTc-hexamethyl-propyleneamine oxime (HMPAO) brain SPECT with ACZ stress simultaneously to a patient with severe coronary artery disease and experienced the abnormality of 201Tl myocardial imaging with ACZ, as did that with dipyridamole. Technetium-99m-HMPAO brain SPECT showed no defect. Brain SPECT with ACZ demonstrated the region of poor coronary vascular reserve, which suggested myocardial ischemia induced by ACZ in a patient with severe coronary artery disease.

Acetazolamide↗
PubMed1998

Growth curve of ruptured aortic aneurysm.

OBJECTIVE: We hypothesized that the aortic aneurysm might grow biexponentially. The object of this study was to determine the biexponential growth curve of aortic aneurysm. DESIGN: A fifteen-year retrospective review of CT images of aortic aneurysm. SETTING: Major cardiovascular referral center. PATIENTS: Patients with true aortic aneurysm who were followed up with CT and performed CT at their aneurysmal ruptures. MEASURES: The largest short-axial diameters of the outer contour of the aneurysms were measured. Aortic aneurysmal diameters were normalized by those at ruptures, and the plots were fitted to the biexponential curve. RESULTS: Eight patients out of 1481 had been followed up with CT scans. In regression analysis, the values fit well to the biexponential equation: d(t) = 0.8345 exp (0.0052 t) + 0.1653 exp (0.8275 t), r = 0.934 where d(t) is the normalized diameter, and t is months before rupture. The first part of the equation mainly expresses the slow growth, and the second expresses the rapid growth shortly before rupture. CONCLUSIONS: Aortic aneurysm began to grow faster at about three months before rupture. It is important to find out the point that the growth of aortic aneurysm changes its rate faster than before, and once the point is observed, elective repair should be considered.

Aged↗
PubMed1998

[Features of MRI diffusion weighted image in early stage of lateral medullary infarction presenting Wallenberg syndrome].

We described early features of MRI diffusion weighted images (DWIs) in three patients with lateral medullary infarction. Patient 1. A 65-year-old woman who complained of vertigo was admitted. Then, DWIs showed a high signal intensity in the right lateral medulla, though T2 weighted images (T2WIs) did not show any abnormalities. On the next day, when the typical symptoms and signs of lateral medullary infarction appeared, the lesion was recognized on both DWIs and T2WIs. Patient 2. A 48-year-old man was admitted 9 hours after he had dizziness, nausea, and repeated vomitings. When a diagnosis of Wallenberg syndrome was made on the neurological examination, MRI DWIs demonstrated a high signal intensity in the right lateral medulla. The lesion became apparent on T2WIs 82 hours after the onset. Patient 3. A 71-year-old man was admitted for nausea, dizziness, and repeated vomitings. A diagnosis of Wallenberg syndrome was made fifty eight hours after the onset, a lesion with high signal intensity in the right lateral medulla was evident on DWIs, but it was faint on T2WIs. We concluded that DWIs is useful in early diagnosis of lateral medullary infarction presenting Wallenberg syndrome.

Aged↗
PubMed1998

[Prophylactic effect of nicorandil on perioperative coronary spasm].

The prophylactic effect of nicorandil on perioperative coronary spasm (CS) in CABG was examined retrospectively. The subjects were 313 patients who had undergone elective CABG. The patients were divided into two groups a control group receiving single administration of nitroglycerine (N = 196) and a nicorandil group receiving both nitroglycerine and nicorandil (4 mg.h-1-8 mg.h-1) (N = 107). The two groups were compared. The incidence of CS was 14 cases (7.1%) in the control group and 6 cases (5.6%) in the nicorandil group, demonstrating a significant difference. With the dose and the administration method employed in this study, no prophylactic effect of nicorandil on perioperative CS has been demonstrated.

Coronary Artery Bypass↗
PubMed1998

[Effects of nitric oxide synthase inhibitor on skin blood flow responses to acute isovolemic hemodilution during halothane and isoflurane anesthesia].

Eighteen dogs under halothane or isoflurane anesthesia were subjected for a study in skin blood flow of the forearm under acute isovolemic hemodilution. Hematocrit was intentionally reduced to about 50% of baseline in ten minutes and hematocrit changes were induced by exchange of blood with hydroxyethyl starch. The skin blood flow increase response, measured by laser Doppler flowmetry, to hemodilution was abolished after inhibition of endogenous nitric oxide synthesis by N omega-nitro-L-arginine methyl ester. Skin blood flow responses to hemodilution and N omega-nitro-L-arginine methyl ester were different between halothane group and isoflurane group. Nitric oxide may have an important part to play in vasodilation during acute isovolemic hemodilution, and it may be affected differently by halothane and isoflurane.

Anesthesia, Inhalation↗
PubMed1998

[A survey of malignant gliomas accompanied with visceral malignancies].

From January 1984 to December 1997, a total of six patients with malignant gliomas accompanied with visceral malignancies were treated in our department. We reviewed their radiological findings and clinical course. They consisted of four patients with glioblastoma and two patients with anaplastic astrocytoma. Classified according to visceral malignancies, three cases had colon cancer and the rest consisted of thyroid, uterus and prostate cancers. In radiological examinations of the brain (CT scans and MR images), these gliomas were relatively well-circumscribed, as if they were metastatic brain tumors. Of all these six cases, two cases survived more than five years and there were two cases in which there was recurrence within a year. Particularly, in four cases, whose gliomas developed after the treatment for visceral malignancies, two cases survived long-term (more than five years) and there was recurrence in only one case. We speculated that visceral malignancies could affect the nature of glioma progression. Thinking about its mechanisms, we hypothesized as follows; (1) visceral malignancies may activate non-specific, or common antitumor, immunity. (2) visceral malignancies may produce some factors which could affect the biological nature of gliomas. (3) glioma accompanied with visceral malignancy may have genetic uniqueness. Although the cases were limited in number, the present study may be helpful in designing the treatment for such cases and in elucidating the invasive nature of gliomas.

Adult↗
PubMed1998

[A case of clinically diagnosed Creutzfeldt-Jakob disease with serial MRI diffusion weighted images].

We reported MRI findings in a 49-year-old woman with clinically diagnosed Creutzfeldt-Jakob disease (CJD). She was admitted to our hospital because of confusion, which initially appeared 5 weeks prior and was rapidly worsened. Two weeks later, she developed myoclonic jerks in her extremities with periodic synchronous discharges on EEG. Six months later, she became mutic. Brain MRI at 3 weeks after the admission demonstrated high signal intensities in the bilateral caudate nuclei and putamina on T2 weighted images (T2WIs). Diffusion weighted images (DWIs) showed hyperintensities in the basal ganglia and in the parietal and occipital cortices. Five weeks later, the abnormal intensities in the basal ganglia were still observed on T2WIs but decreased on DWIs. Five months later, the increased signal intensities in the basal ganglia had disappeared both on T2WIs and DWIs, but new hyperintensities appeared in the insula and the temporal area on DWIs. We concluded that DWIs may be useful for the demonstrations of a lesion in the cerebral cortex and the spread of lesions.

Atrophy↗
PubMed1997

Chemopreventive effects of diosmin and hesperidin on N-butyl-N-(4-hydroxybutyl)nitrosamine-induced urinary-bladder carcinogenesis in male ICR mice.

The chemopreventive effects of 2 flavonoids (diosmin and hesperidin) on N-butyl-N-(4-hydroxybutyl)nitrosamine (OH-BBN)-induced urinary-bladder carcinogenesis were examined in male ICR mice. Animals were divided into 11 groups, and groups 1 to 7 were given OH-BBN (500 ppm) in the drinking water for 6 weeks. Groups 2 to 4 were fed diets containing the test compounds (group 2, 1000 ppm diosmin; group 3, 1000 ppm hesperidin; group 4,900 ppm diosmin + 100 ppm hesperidin) for 8 weeks during the initiation phase, while groups 5 to 7 were fed these diets, respectively, for 24 weeks during the post-initiation phase. Groups 8 to 11 were controls, given only the test compounds or untreated basal diets throughout the experiment (weeks 1 to 32). The incidence of bladder lesions and cell-proliferation activity estimated by enumeration of silver-stained nucleolar-organizer-region-associated proteins (AgNORs) and by the 5-bromodeoxyuridine (BUdR)-labeling index was compared among the groups. Feeding of the test compounds, singly or in combination, during both phases caused a significant reduction in the frequency of bladder carcinoma and preneoplasia. Dietary administration of these compounds significantly decreased the AgNOR count and the BUdR-labeling index of various bladder lesions. These findings suggest that the flavonoids diosmin and hesperidin, individually and in combination, are effective in inhibiting chemical carcinogenesis of the bladder, and that such inhibition might be partly related to suppression of cell proliferation.

Administration, Oral↗
PubMed1997

Creatine phosphate, not ATP, is required for 3' end cleavage of mammalian pre-mRNA in vitro.

The poly(A) tail of a mammalian mRNA is generated by endonucleolytic cleavage and poly(A) addition. Previous studies conducted with nuclear extracts suggested an ATP requirement for the cleavage step. We have reexamined the cofactor requirement, initially with the SV40 late pre-mRNA, which requires for cleavage four protein factors, cleavage and polyadenylation specificity factor, cleavage stimulation factor, cleavage factor I, and cleavage factor II. Using highly purified preparations of these factors, which lacked detectable creatine phosphokinase and ATPase activities, creatine phosphate (CP) was, surprisingly, found to be sufficient to promote efficient cleavage. Although other phosphate compounds substituted poorly or not at all for CP, another phosphoguanidine, arginine phosphate, was fully functional. Notably, ATP was neither necessary nor sufficient, and could in fact inhibit the reaction. Treatment of the purified factors with hexokinase plus glucose (to deplete any contaminating ATP) was without effect, as was addition of EDTA. Using 32P-labeled CP, we found that neither hydrolysis of CP nor phosphate transfer from CP occurred during the cleavage reaction. CP also allowed cleavage of the adenovirus 2 L3 pre-mRNA. However, in this case, ATP both enhanced the reaction and influenced the precise site of cleavage, perhaps reflecting the requirement of poly(A) polymerase for cleavage of this RNA. These results indicate that ATP is not essential for 3' pre-mRNA cleavage and that CP or a related compound can function as a necessary cofactor.

Adenosine Triphosphate↗
PubMed1997

Toxic shock-like syndrome caused by non-group A beta-hemolytic streptococci.

Two patients with rapidly developing shock, multisystem organ failure, and destructive soft-tissue infection caused by groups G and C streptococci are described. Both patients died rapidly despite aggressive treatment. The clinical characteristics cannot be distinguished from those of toxic shock-like syndrome, but Streptococcus pyogenes was not recovered. These strains did not produce any previously identified type of streptococcal pyrogenic exotoxins. These findings suggest that toxic shock-like syndrome can be caused not only by group A but also groups G and C streptococci. The causative strains of toxic shock-like syndrome may have something in common with unknown virulent factors for this syndrome.

Aged↗
PubMed1997

Long G tails at both ends of human chromosomes suggest a C strand degradation mechanism for telomere shortening.

The chromosomes of lower eukaryotes have short telomeric 3' extensions. Using a primer-extension/nick-translation technique and nondenaturing hybridization, we find long 3' G-rich tails at human chromosome ends in mortal primary fibroblasts, umbilical vein endothelial cells, and leukocytes, as well as in immortalized fibroblasts. For all cells tested, >80% of the telomeres have long G-rich overhangs, averaging 130-210 bases in length, in disagreement with the conventional model for incomplete lagging-strand replication, which predicts overhangs on 50% of the chromosome ends. The observed G tails must exist during most of the cell cycle and probably result from degradation of both chromosome ends. The average lengths of the G tails are quantitatively consistent with the observed rates of human chromosome shortening.

Alkalies↗
PubMed1997

Aggressive natural killer cell lymphoproliferative disorder associated with Epstein-Barr viral RNA.

Lymphoproliferative disorder of natural killer cells is a heterogeneous disorder, and an association with Epstein-Barr virus (EBV) is suggested in some cases. A Japanese male presenting with recurrent nasopharyngeal problems developed fever, generalized lymphadenopathy, and hepatosplenomegaly. Separated cells from lymph nodes were shown to have a natural killer (NK) cell, CD2(+), CD3(-), CD16(+), CD56(+), HLA-DR(+) phenotype. A progressive abnormality of hepatic function was associated with hepatorenal failure and death. A serologic study suggested reactivated EBV infection. In situ hybridization (ISH) studies showed Epstein-Barr virus-encoded RNA (EBER)-1 in lymph nodes, with lymphocytes infiltrating the liver and tissue from ethmoid sinus surgery 3 years prior to development of obvious lymphoproliferative disease. Polymerase chain reaction performed on lymph node DNA, using oligonucleotide primers specific for the EBV lymphocyte-determined membrane antigen (LYDMA) gene, revealed a single band, suggesting monoclonal proliferation of the tumor. NK activities of the lymphocytes from the lymph node and peripheral blood were markedly decreased. These findings suggest a close relationship between EBV infection and development of NK cell lymphoproliferative disorder.

Adult↗
PubMed1997

Expression of bcl-2, bax, and bcl-XL proteins in azoxymethane-induced rat colonic adenocarcinomas.

Using western blotting and immunochemical analysis, we investigated alterations in the expression of the apoptosis-related proteins bcl-2, bax, and bcl-X in colonic adenocarcinomas induced by subcutaneous injection of azoxymethane (AOM) (15 mg/kg body weight weekly for 2 wk) into male Sprague-Dawley rats. Expression of the apoptosis-repressor bcl-2 in the colonic tumors was significantly weaker (0.6-fold) than that in adjacent non-neoplastic mucosa. The expression of bax protein, an apoptosis accelerator, was significantly stronger (7.33-fold) in all the tumors than in the non-tumoral mucosa. bcl-XL protein, which functions as a repressor of apoptosis, was significantly upregulated (3.23-fold) in all the tumors when compared with the non-neoplastic mucosa. There was no significant difference between the expression of these proteins in the non-neoplastic mucosa of the AOM-treated rats and in the normal mucosa of saline-treated control rats. As determined by immunohistochemical analysis, the tumor cells had more bax and bcl-X protein. These findings indicate that the regulation of the apoptosis-related proteins bcl-2, bax, and bcl-XL was altered in the AOM-induced colonic neoplastic tissue. In terms of resistance to apoptosis, elevated levels bcl-XL protein may have considerable meaning in this experimental model as well as in human colorectal cancer.

Adenocarcinoma↗
PubMed1997

Use of iodine-123 metaiodobenzylguanidine myocardial imaging to predict the effectiveness of beta-blocker therapy in patients with dilated cardiomyopathy.

It is crucial to predict drug effectiveness in chronic disease, such as dilated cardiomyopathy (DCM), in which the left ventricular (LV) function might be improved by beta-blocker therapy. As the functional improvement effected by beta-blocker therapy takes more than 2 months, we investigated whether iodine-123 metaiodobenzylguanidine (123I-MIBG) imaging could be used to predict drug effectiveness. We studied 13 patients (11 men and two women; mean age, 43+/-13 years) with DCM and seven normal subjects (six men and one woman; mean age, 48+/-16 years). We obtained myocardial single-photon emission tomography (SPET) images 15 min and 4 h after administration of 123I-MIBG (111 MBq). Studies were performed in the patients with DCM before and 1 and 3 months after the administration of metoprolol and in the normal subjects. We calculated the regional 123I-MIBG washout rate (r-WR) in the SPET image, and the global 123I-MIBG washout rate (g-WR) and heart-mediastinum activity ratio (H/M) using the anterior planar image. We classified patients into those showing a >/=5% increase in LV ejection fraction (LVEF) at 3 months compared with LVEF values before the treatment (group I, n=7) and those showing a <5% increase in LVEF (group II, n=6). In group I, the r-WR values at pretreatment and at 1 month and 3 months of treatment, respectively, were 36%+/-19%, 29%+/-14%* and 25%+/-13%* in the anterior segment, 39%+/-17%, 33%+/- 17%** and 28%+/-17%* in the lateral segment, 36%+/- 16%, 31%+/-14%* and 22%+/-12%** in the septal segment and 40%+/-11%, 37%+/-19% and 31%+/-18%* in the inferior segment; the g-WR was 45%+/-11%, 43%+/-10% and 34%+/-9%*, respectively (* P<0.05, ** P<0.01 vs pretreatment). In group II, there were no significant changes in regional or global parameters during the 3-month period. In normal subjects, the r-WR values in each of the anterior, lateral, septal and inferior segments were significantly lower than those in groups I and II. These values were 18%+/-9%, 18%+/-15%, 20%+/-12% and 21%+/-15%, respectively. This study demonstrated that with regional assessment 123I-MIBG SPET imaging can be used to predict the functional improvement of LVEF at 1 month of beta-blocker therapy in patients with DCM.

3-Iodobenzylguanidine↗