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Biomedical subjects

Koichi Hirata

Publications and source records attributed to Koichi Hirata.

At least 19 recordsLinked to original sources
PubMed2003

Axonal Guillain-Barré syndrome associated with axonal Charcot-Marie-Tooth disease.

We report the first case of axonal Guillain-Barré syndrome (GBS) associated with axonal Charcot-Marie-Tooth disease (CMT). A 30-year-old Japanese man, who had suffered leg atrophy and foot deformity since childhood, developed acute weakness in his four limbs following an upper respiratory tract infection. Nerve conduction studies showed low compound muscle action potential (CMAP) and sensory nerve action potential (SNAP) amplitudes in all the nerves tested. Serial studies showed a rapid increase in CMAP amplitude, but no significant change in SNAP, which indicates that the acute event selectively involved motor axons and was superimposed on a baseline motor-sensory axonal neuropathy, probably CMT Type 2. Elevated serum IgG antibodies against GM1 and GM1b, an increase in CSF protein, and rapid clinical and electrophysiological recovery after plasma exchange support the diagnosis of a pure motor axonal form of GBS, acute motor axonal neuropathy. The association may be coincidental, but a particular susceptibility to axonal damage of CMT2 cannot be excluded.

Adult↗
PubMed2003

Bickerstaff's brainstem encephalitis: clinical features of 62 cases and a subgroup associated with Guillain-Barré syndrome.

Bickerstaff reported eight patients who, in addition to acute ophthalmoplegia and ataxia, showed drowsiness, extensor plantar responses or hemisensory loss. This condition has been named Bickerstaff's brainstem encephalitis (BBE). One patient had gross flaccid weakness in the four limbs. Presumably because of the rarity of this disorder, there has been no reported study on a large number of patients with BBE. To clarify its clinical features, we reviewed detailed clinical profiles and laboratory findings for 62 cases of BBE diagnosed by the strict criteria of progressive, relatively symmetrical external ophthalmoplegia and ataxia by 4 weeks, and disturbance of consciousness or hyperreflexia. Ninety-two per cent of the patients involved had had an antecedent illness. Besides ophthalmoplegia and ataxia, disturbance of consciousness was frequent (74%), and facial diplegia (45%), Babinski's sign (40%) and pupillary abnormality and bulbar palsy (34%) were present. Almost all the patients had a monophasic remitting course and generally a good outcome. Serum anti-GQ1b IgG antibody was positive in 66%, and MRI showed brain abnormality in 30% of the patients. Another striking feature was the association with flaccid symmetrical tetraparesis, seen in 60% of the patients. An autopsy study of a BBE patient clearly showed the presence of definite inflammatory changes in the brainstem: there was perivascular lymphocytic infiltration with oedema and glial nodules. Electrodiagnostic study results suggested peripheral motor axonal degeneration. Limb weakness in the BBE cases studied was considered the result of overlap with the axonal subtype of Guillain-Barré syndrome. These findings confirm that BBE constitutes a clinical entity and provide additional clinical and laboratory features of BBE. A considerable number of BBE patients have associated axonal Guillain-Barré syndrome, indicative that the two disorders are closely related and form a continuous spectrum.

Adolescent↗
PubMed2003

Chronic outcome of proximal gastrectomy with jejunal pouch interposition in dogs.

BACKGROUND: To prevent or minimize postgastrectomy complications, proximal gastrectomy with an interposed jejunal pouch has been advocated as an organ-preserving surgical strategy to improve quality of life for the patients. However, the utility of this surgical method has only been evaluated clinically and no reports have been published concerning animal studies. Therefore, we carried out an experiment in beagle dogs to investigate the utility of proximal gastrectomy with an interposed jejunal pouch. METHODS: Female beagle dogs weighting 8.0-10.0 kg were divided into two groups that underwent proximal gastrectomy with jejunal pouch interposition (JP group) and esophagogastrostomy (EG group). The time course of the electrophysiological changes on electromyograms were compared between the JP and EG groups. RESULTS: Electrophysiologically, a significant difference was noted between the two groups on the number of action potentials per unit time, the mean amplitude, and the length of the resting period in the preprandial state. All parameters tended to be normalized sooner after surgery in the JP group. CONCLUSIONS: The clinical superiority of jejunal pouch interposition was suggested experimentally to the same extent on electromyograms.

Action Potentials↗
PubMed2003

Longitudinal changes of anti-ganglioside antibodies before and after Guillain-Barré syndrome onset subsequent to Campylobacter jejuni enteritis.

Anti-ganglioside antibodies frequently are present in sera from patients with Guillain-Barré syndrome (GBS) during the acute phase, but no patients in whom anti-ganglioside antibodies were tested before the onset of the syndrome have been reported. We describe the first case of GBS subsequent to Campylobacter jejuni infection, in which longitudinal changes in anti-ganglioside antibody titers were measured before and after the onset of limb weakness. Serum antibody titers against GM1 (IgM/IgG), GM1b (IgM/IgG), GalNAc-GD1a (IgM/IgG), and GD1b (IgG) were highest on the day of onset, but negative before onset. Anti-C. jejuni IgG and IgA antibody titers paralleled those of the anti-ganglioside antibodies, indicative that C. jejuni infection triggered anti-ganglioside antibody production. Press et al. [J. Neurol. Sci. 190 (2001) 41] reported that anti-ganglioside antibody titers peaked during the recovery phase, but our findings are counter to theirs. We speculate that anti-ganglioside antibodies are the primary effectors of nerve damage in GBS.

Antibodies↗
PubMed2003

Efficacy of SPIO-MR imaging in the diagnosis of liver metastases from colorectal carcinomas.

AIM: To determine whether superparamagnetic iron oxide-enhanced magnetic resonance imaging (SPIO-MRI) could replace intravenous contrast-enhanced spiral CT (iv-CT) and spiral CT during arterial portography (CTAP) combined with spiral CT hepatic angiography (CTHA) in the diagnosis of liver metastases from colorectal carcinomas. METHODS: Twenty-six adult patients with liver metastases were studied preoperatively by means of iv-CT, CTAP/CTHA, and SPIO-MRI. Preoperative diagnoses using iv-CT, CTAP/CTHA, and SPIO-MRI were compared with intraoperative and pathological findings in resected specimens. The gold standard for the lesions that were resected was histological examination. Intraoperative findings represented the gold standard for lesions that were not resected. RESULTS: Twenty-six patients were found to have a total number of 43 liver metastases. The sensitivities of iv-CT, CTAP/CTHA, and SPIO-MRI were 74.4, 100, and 90.7%, respectively. SPIO-MRI was significantly superior to iv-CT (p < 0.05). The positive predictive values of iv-CT, CTAP/CTHA, and SPIO-MRI were 97.0, 91.5, and 100%, respectively. CTAP/CTHA yielded four false-positive lesions. In contrast, we detected no false-positive findings using SPIO-MRI. CONCLUSIONS: These results suggest that SPIO-MRI might not completely replace CTAP/CTHA, but could replace iv-CT in the diagnosis of liver metastases from colorectal carcinomas. It is thought that SPIO-MRI is a promising imaging modality for diagnosing liver metastases in patients with colorectal carcinoma because of its relatively high sensitivity and extremely high specificity.

Adult↗
PubMed2003

Role of inducible nitric oxide synthase in pig liver transplantation.

BACKGROUND: Previously, we clarified the role of inducible nitric oxide synthase (iNOS) and the protective effect of an iNOS inhibitor in warm ischemia and reperfusion model. In this study, we investigated whether the same effects would be obtained by iNOS inhibitor in liver transplantation model. MATERIAL AND METHODS: Orthotopic liver transplantation was performed in pigs in the usual manner after about 6 h of cold preservation in University of Wisconsin solution. Aminoguanidine hemisulfate (AG) was used as the iNOS inhibitor and AG was administered intraportally at the dose of 10 mg/kg just after reperfusion. Two experimental groups were subjected, control group (n = 10), and AG group (n = 10). We investigated changes of serum nitrite/nitrate (NOx) and aspartate aminotransferase (AST). Expression of iNOS was examined by immunohistochemistry, including a double immunofluorescnce technique in combination with cofocal laser scanning microscopy. RESULTS: Serum NOx and AST were significantly lower in the AG group. Histological hepatic damage and thrombocyte thrombi were attenuated in the AG group. Expression of iNOS was recognized strongly at Kupffer cells and neutrophils in the centrilobular region of liver after reperfusion by cofocal laser scanning microscopy. Moreover, iNOS staining was attenuated in AG group compared with control group. CONCLUSIONS: These results indicate that hepatic ischemia and reperfusion injury in liver transplantation might be triggered by iNOS expression of Kupffer cells and neutrophils, and attenuated by administration of an iNOS inhibitor. Moreover, AG showed down regulation of iNOS expression after reperfusion.

Animals↗
PubMed2003

Surgical influence on TH1/TH2 balance and monocyte surface antigen expression and its relation to infectious complications.

Malignancy and operation for it cause several alterations in immune function that are considered to be concerned with the development of infectious complications. Forty-three patients who underwent curative surgery for gastrointestinal malignancies were entered into this study and were divided into two groups, those with and those without postoperative infection. Changes in the proportion of Th1/Th2 subsets in CD4(+) T cells and the expression of human leukocyte antigen (HLA)-DR and CD16a molecules on monocytes were measured by flow cytometry before and after surgery. We performed intracellular cytokine stainings to exactly detect Th1/Th2 subsets. The proportions of interferon- gamma-producing CD4(+) T (Th1) cells in the preoperative state were almost equal in the two groups, and the proportion decreased on postoperative day (POD) 1 in both groups. On POD 7, the proportion of Th1 cells recovered to the preoperative level in the noninfection group, while the suppression was further reinforced in the infection group (26.8% versus 18.3%, p < 0.005). In contrast, the proportion of interleukin-4-producing CD4(+) T (Th2) cells in the infection group (11.3%) was already suppressed in the preoperative state when compared with the noninfection group (17.3%, p < 0.005). Changes in HLA-DR and CD16a expression on monocytes were similar to the changes in the proportion of Th1 cells. These results indicate that the suppression of Th1 cell and monocyte functions during the early phase of the postoperative course was directly related to the occurrence of infectious complications and that several immunological impairments have already occurred in the preoperative state in cancer patients.

Aged↗
PubMed2003

Apoptosis and necrosis after warm ischemia-reperfusion injury of the pig liver and their inhibition by ONO-1714.

BACKGROUND: It is still controversial whether a major mode of cell death during hepatic ischemia-reperfusion (I/R) injuries is apoptosis or necrosis. Moreover, the correlation between these cell deaths and the effects of a novel inducible nitric oxide synthase inhibitor (ONO-1714) has not been studied before. METHODS: Pigs were subjected to 180 min of hepatic warm I/R under extracorporeal circulation. The control group was not administered ONO-1714. In the ONO-1714 group, ONO-1714 was administered 5 min before ischemia at a dose of 0.05 mg/kg through a portal vein catheter. The apoptotic and necrotic changes after reperfusion were examined by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling and hematoxylin-eosin staining. Nitrotyrosine, active caspase-3, and cytochrome c were examined by immunohistochemistry. The plasma NO + NO, aspartate aminotransferase, and lactate dehydrogenase levels were also examined. RESULTS: In the control group, the frequency of apoptotic cells was only 2.6%; nevertheless, that of necrotic cells was 37% at 24 hr after reperfusion. ONO-1714 significantly attenuated apoptosis and necrosis, the expression of nitrotyrosine, and the increases of the plasma aspartate aminotransferase, lactate dehydrogenase, and NO(2)- + NO(3)- levels in the reperfusion phase. CONCLUSIONS: A major mode of cell death during hepatic warm I/R injury was necrosis, and apoptosis was not dominant. These necrotic changes were caused by the excess production of peroxynitrite, and ONO-1714 greatly attenuated I/R injuries as the result of inhibition of the peroxynitrite production.

Amidines↗
PubMed2003

Randomized controlled trial comparing oral doxifluridine plus oral cyclophosphamide with doxifluridine alone in women with node-positive breast cancer after primary surgery.

PURPOSE: We compared the therapeutic usefulness of doxifluridine (5'-DFUR) alone and a combination of 5'-DFUR plus cyclophosphamide (CPM), both of which are considered effective against advanced and recurrent breast cancer, to determine which treatment is more beneficial as postoperative adjuvant chemotherapy. PATIENTS AND METHODS: A total of 1,131 women with node-positive primary breast cancer were randomly assigned after primary surgery to receive 5'-DFUR alone or 5'-DFUR plus CPM. All patients initially received 5'-DFUR in an oral dose of 1,200 mg/d for 4 weeks, starting 4 weeks after surgery. Chemotherapy was then not given for 2 weeks. Patients in the 5'-DFUR group subsequently received five 4-week cycles of treatment consisting of oral 5'-DFUR (1,200 mg/d) for the first 2 weeks and no chemotherapy for the next 2 weeks. Those assigned to the 5'-DFUR plus CPM group also received oral CPM 100 mg/d for the first 2 weeks and no chemotherapy for the next 2 weeks. Women 50 years or older concurrently received 20 mg/d of tamoxifen for 2 years in both groups. RESULTS: Of the 1,088 eligible women, 546 were assigned to receive 5'-DFUR alone and 542 were assigned to receive 5'-DFUR plus CPM. Overall disease-free survival was significantly better in women who received 5'-DFUR plus CPM than in those who received 5'-DFUR alone (log-rank test, P =.021). Toxic effects occurred in 20.0% of patients (109 of 546) in the 5'-DFUR group and 32.3% of patients (175 of 542) in the 5'-DFUR plus CPM group (chi(2) test, P <.001). CONCLUSION: Combination therapy with 5'-DFUR plus CPM is more effective in preventing recurrence than 5'-DFUR alone.

Administration, Oral↗
PubMed2003

Acute motor axonal neuropathy rabbit model: immune attack on nerve root axons.

Macrophages in the periaxonal space and surrounding intact myelin sheath are the most prominent pathological feature of acute motor axonal neuropathy (AMAN). We describe this characteristic in nerve roots from paralyzed rabbits immunized with bovine brain ganglioside or GM1. IgG was deposited on nerve root axons. Distal nerve conduction was preserved, and late F wave components were absent during the acute phase. Initial lesions were located mainly on nerve root axons, as in human AMAN. This study thus provides supportive evidence that the rabbits constitute a model of AMAN.

Action Potentials↗
PubMed2003

Ten-year results of a randomized trial on adjuvant chemo-endocrine therapy with tamoxifen for stage II breast cancer.

BACKGROUND: A prospective randomized multi-center study was undertaken for 2 years and 3 months from November 1982, with the aim of examining the significance of using a combination of futraful (FT) and tamoxifen (TAM) for postoperative adjuvant therapy for stage II breast cancer after curative surgery. METHODS: Patients were divided into two groups and received one of the following treatment protocols: treatment A, intravenous administration of doxorubicin (DOX) 20 mg/body on the day of surgery and 10 mg/body the next day, followed by oral FT 600 mg/day for 2 years from the 14th day after surgery; treatment B, the same pattern of DOX administration followed by combined therapy with FT and TAM 20 mg/day for 2 years. The number of patients was 428 (treatment A 210 and treatment B 218), of whom 418 (97.7%) were followed for 10 years for analysis. RESULTS: Significantly higher 5- and 10-year overall survival (OS) rates were observed with treatment B compared with treatment A (p=0.0101 and 0.0219). Node-positive patients appeared to derive more benefit from TAM than node-negative patients. The difference in 10-year OS between treatment A and treatment B was more evident than that of the 5-year OS in patients with more than 4 positive nodes (p=0.0313 vs. 0.0479). No increase in adverse reactions was seen as a result of combining TAM with FT. CONCLUSION: The study results demonstrate that for stage II breast cancer concomitant administration of FT and TAM is superior to FT alone for postoperative adjuvant therapy, and administration of TAM for 2 years may contribute not only to 5-year survival rates but also to 10-year survival rates of node-positive patients.

Adenocarcinoma↗
PubMed2003

Patients with chronic inflammatory demyelinating polyneuropathy initially diagnosed as Guillain-Barré syndrome.

Progression periods for Guillain-Barré syndrome (GBS) differ from those of chronic inflammatory demyelinating polyneuropathy (CIDP), but physicians could classify patients with CIDP within 4 weeks of onset as GBS. We studied and report the frequency of GBS patients who were later diagnosed as CIDP (11/663, 2%). Plasmapheresis or intravenous immunoglobulin transiently improved all the 11 patients, who 11 progressed slowly or had a relapse beyond the 8 weeks, and the other 2 suffered a relapse between 4 and 8 weeks from the onset. Three patients had had an antecedent infectious illness. CSF albumino-cytological dissociation was detected in 6 patients within 2 weeks of onset. Recognition of the existence of such patients is important for the early diagnosis and treatment of those patients with CIDP for whom GBS has been diagnosed at onset.

Adult↗
PubMed2003

Gene expression screening using a cDNA macroarray to clarify the mechanisms of peritoneal dissemination of pancreatic cancer.

PURPOSE: Pancreatic cancer is associated with the poorest prognosis of any digestive cancer due to the high incidence of peritoneal dissemination, which is the cause of death in most cases. To determine the mechanisms of peritoneal dissemination in pancreatic cancer, we established a mouse model of high peritoneal dissemination. METHODS: A novel highly peritoneal-disseminating cell line was established from the human pancreatic cancer cell line; CAPAN-1. The new cell line, CAPAN-1P4a, was established from CAPAN-1 by repeated in vivo selection (four times) of the tumor cell line. To clarify the candidate genes implicated in peritoneal dissemination of pancreatic cancer, global gene expression screening was done using a cDNA macroarray. RESULTS: CAPAN-1P4a cells showed 100% metastasis 3 weeks after injection and high reproducibility in the inoculated mice. Twenty-seven genes were upregulated and 14 genes were downregulated in CAPAN-1P4a cells compared with CAPAN-1 cells. The genes differentially expressed in the two cell lines were included as tumor suppressor/apoptosis genes, regulatory transcription factor, membrane receptors, cell adhesion protein, membrane receptors, and so on. CONCLUSIONS: Our established CAPAN-1P4a model offers a new means of conducting global gene expression analysis of pancreatic cancer cells with peritoneal dissemination and it has the potential to provide new insights into the mechanism of peritoneal dissemination in human pancreatic cancer.

Adenocarcinoma↗
PubMed2003

CDR3 spectratyping analysis of the T cell receptor repertoire in Guillain-Barré and Fisher syndromes.

Several autoimmune and infectious disorders show oligoclonal expansion of particular T cell phenotypes. The extent of T cell involvement in the pathogenesis of Guillain-Barré syndrome (GBS), a post-infectious autoimmune neuropathy, however, is not clear. To identify the pathogenic T cell phenotypes in GBS and Fisher syndrome (FS), variations in T cell receptor use of the V beta 1-24 and V delta 1-5 chain genes were analyzed at complementarity-determining region 3 level in 119 patients with GBS or FS. Overall, V beta and V delta spectratypes were expanded more frequently in patients with GBS (V beta in 77%, V delta in 53%) or FS (V beta in 75%, V delta in 65%) than in the healthy controls (V beta in 59%, V delta in 38%). No particular spectratype was significantly associated with GBS or FS. Subgrouping the patients by Campylobacter jejuni serology and anti-ganglioside IgG antibodies also failed to detect particular spectratype gene use. The frequency of V beta 5.2 expansion tended to be higher in patients with positive Haemophilus influenzae serology (50%) than in the controls (7%), but the difference was not significant. Our findings show that oligoclonal expansion of T cells bearing particular type T cell receptor V beta and V delta genes frequently occurs in GBS and FS, suggestive that T cells mediate the development of these neuropathies. The predominant phenotypes vary, even within subgroups of patients with a syndrome of single etiological origin or those with uniform serological features.

Acute Disease↗
PubMed2003

Reduced brain electric activities of frontal lobe in cortical cerebellar atrophy.

OBJECTIVE: To assess the relationship between cerebellum and brain cortical activity without motor factors, we recorded the mid-latency auditory evoked responses (MLRs) with simultaneous recording of the electroencephalography (EEG) at rest in patients with 'pure cortical cerebellar atrophy (CCA)'. METHODS: We studied 12 normal control subjects and non-demented 'pure CCA' patients determined by quantitative magnetic resonance imaging analysis. A comprehensive neuropsychological test battery assessed intelligence, frontal lobe function and word fluency. Spontaneous eyes-closed resting EEG and MLRs were recorded from 20 scalp electrodes and analysed with low-resolution electromagnetic tomography (LORETA) to compute the 3-dimensional intracerebral distribution of electric activity. RESULTS: Neuropsychological tests revealed no differences between CCA and the control. Analysis of EEG and MLRs using classical methods also did not reveal any differences. LORETA analysis indicated significant decrease of alpha2 activity in the left inferior frontal gyrus in CCA. On MLRs, the most significant difference was observed at P1 component, and CCA patients showed significant decrease at the right superior frontal gyrus. CONCLUSIONS: Our results indicated that the frontal lobe and ascending reticular activating system are inhibited in CCA patients, and suggested the involvement of the cerebellum in cortical electric activities irrespective of motor adjunct. SIGNIFICANCE: Quantitative EEG and MLR measurements with LORETA pointed out frontal lobe hypoactivities in pure CCA patients.

Aged↗
PubMed2003

Quantification of vascular endothelial growth factor-C and its receptor-3 messenger RNA with real-time quantitative polymerase chain reaction as a predictor of lymph node metastasis in human colorectal cancer.

BACKGROUND: This study was undertaken to determine whether vascular endothelial growth factor-C (VEGF-C) and the expression of its receptor VEGF receptor-3 (VEGFR-3) are correlated with lymph node metastasis in human colorectal cancer and whether their expression levels might be used to predict lymph node metastasis. METHODS: Fifty-three surgical specimens of colorectal cancer with (n = 24) or without (n = 29) lymph node metastasis were studied. The messenger RNA (mRNA) expression of VEGF-C and VEGFR-3 was quantified with a new method for kinetic quantitative polymerase chain reaction (PCR), real-time quantitative (RTQ) reverse transcriptase-PCR. In addition, their protein expressions were assessed immunohistochemically. RESULTS: The VEGF-C mRNA level in primary tumors correlated with VEGF-C protein expression, lymph node metastasis, and lymphatic invasion. Sixteen of 24 patients with lymph node metastasis showed VEGF-C mRNA overexpression. Morphologically, VEGF-C protein expression in primary tumors showed a statistically significant relationship with lymph node metastasis and lymphatic invasion. CONCLUSION: Real-time quantitative reverse transcriptase-PCR is a sensitive method for detection and quantification of VEGF-C and VEGFR-3 mRNA expression. Furthermore, the expression levels of VEGF-C mRNA and protein in colorectal cancer are correlated with lymph node metastasis and lymphatic invasion.

Aged↗