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Biomedical subjects

H Ito

Publications and source records attributed to H Ito.

At least 235 records · Page 13Linked to original sources
PubMed2001

Antileishmanial activity of hydrolyzable tannins and their modulatory effects on nitric oxide and tumour necrosis factor-alpha release in macrophages in vitro.

A series of 27 hydrolyzable tannins and related compounds was tested for antiparasitic effects against both extracellular promastigote and intracellular amastigote Leishmania donovani organisms. In parallel, the compounds were evaluated for their immunomodulatory effects on macrophage functions, including release of nitric oxide (NO), tumour necrosis factor-alpha (TNF-alpha) and interferon (IFN)-like properties using several functional assays. Of the series of polyphenols tested, only gallic acid (54 microM NO) and its methyl ester (32 microM NO) induced murine macrophage-like RAW 264.7 cells to release NO in appreciable amounts (IFN-gamma/LPS 119 microM NO). The in vitro TNF-inducing potential of the polyphenols examined increased in the order of oligomeric ellagitannins (EC(50) > 25 microg/ml) < monomeric ellagitannins, gallotannins (EC(50) 8.5 to > 25 microg/ml) < C-glucosidic ellagitannins, dehydroellagitannins (EC(50) 0.6 - 2.8 microg/ml) at the host cell subtoxic concentration of 50 microg/ml. Furthermore, promastigotes of Leishmania donovani were assayed in the presence of these polyphenols and the results showed that none of the compounds was significantly toxic (EC(50) > 25 microg/ml) to the extracellular forms. In contrast, all polyphenols showed pronounced antileishmanial activities (EC(50) < 0.4 - 12.5 versus 7.9 microg/ml for Pentostam) against intracellular amastigotes of L. donovani residing within RAW cells. Noteworthy, most compounds exhibited low cytotoxicity against the murine host cells (EC(50) >25 microg/ml). Furthermore, some ellagitannins and the majority of dehydroellagitannins induced potent interferon-like activities as reflected by inhibition of the cytopathic effect of encephalomyocarditis virus on fibroblast L929 cells. This is the first report on hydrolyzable tannins as a new class of natural products with leishmanicidal activity including their potential for inducing the release of NO, TNF and IFN-like activity in macrophage-like RAW cells.

Animals↗
PubMed2001

AlphaB-crystallin phosphorylated at Ser-59 is localized in centrosomes and midbodies during mitosis.

We have reported that the three serine residues in alphaB-crystallin are phosphorylated under various stress conditions. We prepared affinity-purified antibodies recognizing each of the phosphorylated serine residues (Ser-19, Ser-45, and Ser-59, respectively) in alphaB-crystallin with peptides (p19S, p45S, or p59S) that contained the corresponding phosphorylated serine residue. Immunocytochemically anti-p45S antibodies stained the cytoplasm of mitotic cells (J. Biol. Chem. 273, 28,346-28,354). We have now found that the anti-p59S antibodies recognize centrosomes and midbodies of dividing cells. alphaB-Crystallin was the only protein recognized by the anti-p59S antibodies in Western blot analyses of isolated centrosome fractions. alphaB-Crystallin phosphorylated at Ser-59 was localized at the microtubule organizing centers by means of double staining with anti-beta-tubulin antibody in aster formation analysis and was co-localized with gamma-tubulin in centrosomes. Gamma-Tubulin was co-immunoprecipitated with alphaB-crystallin in U373 glioma cell extracts. On the other hand, the location of the phosphorylated alphaB-crystallin deviated from that of alpha-tubulin or gamma-tubulin in the midbody region. Taken together with the evidences that several chaperones are distributed to centrosomes, these results suggest that alphaB-crystallin as a chaperone might be also involved in the quality control of proteins.

3T3 Cells↗
PubMed2001

Cerebral vasospasm following transsphenoidal removal of a pituitary adenoma.

We report a case of pituitary macroadenoma that developed symptomatic vasospasm 12 days after transsphenoidal removal, but showed an excellent recovery following active treatment identical to those for vasopasm following aneurysmal subarachonid haemorrhage. Subarachnoid haematoma in the basal cisterns secondary from postoperative intracapsular haemorrhage was the most probable cause of the vasopasm.

Adenoma↗
PubMed2001

Dynamic helical CT-guided needle localization of non-palpable and mammographically occult breast lesions. Case reports.

Dynamic helical CT-guided needle localization of non-palpable and mammographically occult breast lesions is described. Dynamic helical CT-technique enabled fast volume scanning of the whole breast during the early contrast enhancement phase, which provided sufficient contrast to localize the target lesions. The procedures were successfully completed without complications.

Biopsy, Needle↗
PubMed2001

Anti-alpha2 integrin antibody induces secretion and activation of 72-kDa progelatinase by human fibroblasts.

We examined the effects of the extracellular matrix proteins fibronectin, laminin, and matrigel on 72-kDa progelatinase secretion by human lip fibroblasts (KD) and skin fibroblasts (MRC9 and HSF). By gelatin zymography, 1.7 +/- 0.2-fold, 1.7 +/- 0.2-fold, and 1.8 +/- 0.3-fold increases were observed in 72-kDa progelatinase secretion from KD cells treated with fibronectin, laminin, and matrigel, respectively. Laminin and matrigel, but not fibronectin, stimulated 72-kDa progelatinase secretion from HSF cells. Fibronectin, laminin, and matrigel did not stimulate 72-kDa progelatinase secretion by MRC9 cells. Anti-alpha2 integrin antibody-stimulated 72-kDa progelatinase secretion and induced the 62-kDa activated form of 72-kDa progelatinase by KD cells. Activated p42 MAP kinase (MAPK) expression was down-regulated by anti-alpha2 integrin antibody. Anti-alpha2 integrin antibody stimulated 72-kDa progelatinase secretion by HSF cells without inducing the 62-kDa activated form. The data suggest that interaction between fibroblasts and extracellular matrix components via alpha2 integrin plays an important role in regulating secretion and activation of 72-kDa gelatinase and that down-regulation of activated p42 MAPK may be involved in the 72-kDa progelatinase activation mechanism.

Antibodies↗
PubMed2001

Serum immunosuppressive acidic protein as a potent prognostic factor for patients with metastatic renal cell carcinoma.

BACKGROUND: Estimation of survival probability of individual patients with metastatic renal cell carcinoma was difficult owing to diverse prognostic factors. We analyzed serum immunosuppressive acidic protein (IAP) levels and the cutoff value, then tested its validity for assessing patients' prognoses. METHODS: Serum IAP was measured longitudinally in 84 patients with metastatic disease. Before therapy, cutoff levels of IAP were tested every 20 microg/ml between 600 and 1200 microg/ml. The prognostic importance of IAP and its cutoff level was estimated. RESULTS: The cutoff level of IAP was set at 800 microg/ml for 40 patients who had metastatic disease with the primary tumor in situ and for 44 patients with recurrent disease. IAP was found to be a significant prognostic factor for both patient groups. CONCLUSIONS: Serum IAP is an important prognostic factor for patients with metastatic renal cell carcinoma. Stratification of patients according to prognosis is feasible using the cutoff level.

Adult↗
PubMed2001

A case of lung metastasis from endometrial adenoacanthoma 17 years after initial treatment.

In March 1982, a 60-old woman presented with an International Federation of Gynecology and Obstetrics grade 1, stage Ib endometrial adenoacanthoma, histological subtype of endometrial carcinoma. The patient underwent radical hysterectomy and was followed up for 10 years, without disease. In August 1998, an abnormal shadow in the right lung was suggested on a chest X-ray film at her routine health check-up and she came to our hospital for further evaluation. A thin-section computed tomographic scan of the chest suggested a malignant lung tumor, but the diagnosis remained tentative. Open biopsy was recommended, but the patient refused and was followed up on an outpatient basis. In November 1999, a thin-section computed tomographic scan of the chest revealed a slightly enlarged tumor and laboratory examination showed a high serum progastrin-releasing peptide concentration of 90.7 pg/ml. We performed partial resection of right upper lobe with video-assisted thoracic surgery. Pathological examination confirmed the lung tumor had metastasized from endometrial adenoacanthoma. Immunohistochemical stainings of estrogen receptor and progesterone receptor were positive both in the primary and lung tumor, only in the component of adenocarcinoma. After surgery, the serum progastrin-releasing peptide concentration remained unchanged. The patient is currently alive and free of disease.

Adenocarcinoma↗
PubMed2001

A large family of class III plant peroxidases.

Class III plant peroxidase (POX), a plant-specific oxidoreductase, is one of the many types of peroxidases that are widely distributed in animals, plants and microorganisms. POXs exist as isoenzymes in individual plant species, and each isoenzyme has variable amino acid sequences and shows diverse expression profiles, suggesting their involvement in various physiological processes. Indeed, studies have provided evidence that POXs participate in lignification, suberization, auxin catabolism, wound healing and defense against pathogen infection. Little, however, is known about the signal transduction for inducing expression of the pox genes. Recent studies have provided information on the regulatory mechanisms of wound- and pathogen-induced expression of some pox genes. These studies suggest that pox genes are induced via different signal transduction pathways from those of other known defense-related genes.

Gene Expression Regulation, Plant↗
PubMed2001

Middle-term results of Salter innominate osteotomy.

This study evaluated middle-term clinical and radiographic results of Salter innominate osteotomy for treatment of dysplastic, subluxated, or congenitally dislocated hips. Thirty-five hips in 33 patients with a mean age at index surgery of 4 years 7 months were followed up for an average of 16.5 years. Radiographic center-edge angle of Wiberg, acetabular index, and regularity of the femoral head were evaluated. Fifteen (43%) hips were in Group I, 11 (31%) hips were in Group II, six (17%) hips were in Group III, and three (9%) hips were in Group IV according to the Severin classification. Significant differences were found in the preoperative and recent center-edge angle (average, 1.1 degrees and 28.8 degrees in the excellent and good groups versus -5.3 degrees and 15.0 degrees in the fair and poor groups) and regularity of the femoral head (very irregular versus others). The current results indicate that after middle-term followup, Salter innominate osteotomy is an effective treatment. The authors conclude this procedure is indicated in patients who meet the criteria proposed by Salter.

Child↗
PubMed2001

Cerebrospinal fluid and plasma concentrations of nitric oxide metabolites in postoperative patients with subarachnoid hemorrhage.

OBJECTIVE: To measure cerebrospinal fluid and plasma concentrations of nitrate and nitrite as indicators of nitric oxide production in adults after subarachnoid hemorrhage (SAH). DESIGN: A prospective, clinical study. SETTING: Multidisciplinary intensive care unit. PATIENTS: Nine patients (three males and six females, aged 29-64 yrs) with aneurysm-induced SAH were studied. Glasgow Coma Scale score on admission ranged from 9 to 15. Ruptured aneurysms were clipped within 72 hrs of ictus, and then conventional hypervolemic, hemodilution, and induced hypertension methods were applied. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Nitrate and nitrite concentrations of patients were examined sequentially by a capillary zone electrophoresis every day for 13 days. As a control group, cerebrospinal fluid was sampled from patients (n = 9, six males and three females, aged 30-60 yrs) without neurologic disorders who underwent spinal taps for spinal anesthesia, and plasma from healthy human volunteers (n = 43, 21 males and 22 females, aged 23-49 yrs). There were no significant differences over time in cerebrospinal fluid nitrate concentrations after SAH. Concentrations of cerebrospinal fluid nitrate after SAH were increased compared with control values. Plasma nitrate concentration was decreased compared with control values, but the value on day 14 was increased significantly (p < .05) compared with those during days 2-11. Plasma and cerebrospinal fluid nitrite concentrations after SAH were similar to those in control subjects. Similar concentrations of nitric oxide metabolite in plasma and cerebrospinal fluid were observed between the patients with and without symptomatic vasospasm. CONCLUSION: The increase of cerebrospinal fluid nitrate after SAH may attribute to the endogenous nitric oxide production in the injured brain.

Adult↗
PubMed2001

Changes in human regional cerebral blood flow and cerebral blood volume during visual stimulation measured by positron emission tomography.

The hemodynamic mechanism of increase in cerebral blood flow (CBF) during neural activation has not been elucidated in humans. In the current study, changes in both regional CBF and cerebral blood volume (CBV) during visual stimulation in humans were investigated. Cerebral blood flow and CBV were measured by positron emission tomography using H(2)(15)O and (11)CO, respectively, at rest and during 2-Hz and 8-Hz photic flicker stimulation in each of 10 subjects. Changes in CBF in the primary visual cortex were 16% +/- 16% and 68% +/- 20% for the visual stimulation of 2 Hz and 8 Hz, respectively. The changes in CBV were 10% +/- 13% and 21% +/- 5% for 2-Hz and 8-Hz stimulation, respectively. Significant differences between changes in CBF and CBV were observed for visual stimulation of 8 Hz. The relation between CBF and CBV values during rest and visual stimulation was CBV = 0.88CBF(0.30). This indicates that when the increase in CBF during neural activation is great, that increase is caused primarily by the increase in vascular blood velocity rather than by the increase in CBV. This observation is consistent with reported findings obtained during hypercapnia.

Adult↗
PubMed2001

Role of angiotensin II type 1 receptor in the leucocytes and endothelial cells of brain microvessels in the pathogenesis of hypertensive cerebral injury.

OBJECTIVES: To elucidate the mechanisms of activation of polymorphonuclear neutrophils (PMNs) and their adhesion to endothelial cells in hypertensive cerebral injury, and to determine the effects of angiotensin II type 1 (AT1) receptor antagonism on PMNs and endothelial cells. DESIGN: We examined expression of AT1 receptor in PMNs in relation to that in endothelial cells of brain microvessels, using mature stroke-prone spontaneously hypertensive rats (SHRSP). METHODS: To investigate the expression of AT1 receptor, we used 23-week-old male spSHRs and age-matched Wistar-Kyoto (WKY) rats. For the effects of AT1 receptor blockade, the AT1 receptor antagonist, TCV-116, was orally administered at a dosage of 0.5 mg/kg per day for 4 weeks in rats from age 19 weeks. A PMN-rich fraction was obtained by density gradient using Ficol-hypaque. AT1 receptor expression in PMNs was investigated by immunohistochemistry (avidin-biotinylated peroxidase complex method) and reverse transcriptase-polymerase chain reaction (RT-PCR). Expression of macrophage-1 (Mac-1) in PMNs was examined by flow cytometry. Expression of intercellular adhesion molecule-1, glucose transporter-1 and fibrinogen in the cerebral cortex (occipital region) was investigated by immunohistochemistry. RESULTS: AT1 receptor was identified in PMNs by both immunohistochemistry and RT-PCR. It was also detected in the cerebral cortex. Expression in both types of cells was much more intense in spSHRs than in WKY rats. AT1 receptor antagonism ameliorated the enhanced expression of Mac-1 in PMNs. In addition, it was confirmed that enhanced expression of adhesion molecules and increased permeability of brain microvessels were decreased by AT1 receptor antagonism. CONCLUSIONS: The results indicate that both PMNs and brain microvessel endothelial cells possess AT1 receptor, that AT1 receptor antagonism ameliorates endothelial injury via inhibition of PMNs and endothelial cell adhesion, and that angiotensin II must be a key factor in hypertensive endothelial injury.

Angiotensin Receptor Antagonists↗
PubMed2001

Reproducibility of [11 C]FLB 457 binding in extrastriatal regions.

Extrastriatal D2 dopamine receptors represent an important target of research into the pathophysiology and pharmacotherapy of psychiatric disorders. The high affinity radioligand [11C]FLB 457 makes possible the measurement of low concentrations of D2 receptors in extrastriatal regions using positron emission tomography (PET). The aim of this study was to assess the test/retest variability and reliability of [11C]FLB 457 binding using a reference tissue model. Eight healthy male subjects (aged 20-33 years) underwent two [11C]FLB 457 PET examinations. Radioactivity in the cerebellum was used as the reference. The binding potentials (BPs) for five cortical regions of interest (ROIs) were calculated using the reference tissue model. The BP was also calculated for each pixel in the form of parametric images. Reproducibility was assessed both for the ROI method and for the parametric images. The test/retest reproducibility for [11C]FLB 457 binding was good, with a mean variability ranging from 4.5% for the thalamus to 15.5% for the hippocampus. The parametric images also demonstrated good reproducibility. These results support the suitability of using [11C]FLB 457 for the quantitative evaluation of extrastriatal D2 receptors and for protocols requiring repeated measurements in the same individual.

Adult↗
PubMed2001

Epigenetic regulation of the KAI1 metastasis suppressor gene in human prostate cancer cell lines.

Expression of the KAI1 gene, a metastasis-suppressor for prostate cancer, is reduced in all foci of prostatic metastasis. The altered regulatory mechanism is not strongly related to mutations or allelic losses of the KAI1 gene in prostate tumors. Since transcriptional silencing of genes has been found to be caused by epigenetic mechanisms, we have investigated the involvement of this epigenetic regulation of KAI1 expression in prostate cancers. The methylation status of the KAI1 promoter region was examined by restriction-enzyme digestion and sequencing, after amplifying a 331-bp fragment in the GC-rich promoter region from 4 human prostate cancer cell lines treated with bisulfite. The same 4 cell lines were also exposed to various concentrations of the demethylating agent, 5-aza-2'-deoxycytidine (5-AzaC) and / or the histone deacetylase inhibitor, trichostatin A (TSA). To clarify the influence of epigenetic modification on reduced KAI1 mRNA expression in the tumor cells, RT-PCR and northern-blot analyses were performed. Bisulfite-sequencing data showed a few methylated CpG islands in the promoter. RT-PCR analysis of 5-AzaC and / or TSA-treated cells indicated reversal of suppression of KAI1 transcription in two cell lines (PC-3 and DU-145), although the expression could not be detected by northern blots. From these results, it is suggested that epigenetic change is not the main mechanism of KAI1 down-regulation, though there remains a possibility that methylation in a more upstream region might be associated with this regulation.

Adenocarcinoma↗
PubMed2001

Nonsurgical management of ruptured pseudoaneurysm in patients with hepatobiliary pancreatic diseases.

OBJECTIVE: Rupture of a pseudoaneurysm is an unusual complication after surgical and interventional treatments in patients with hepatobiliary pancreatic diseases. However, it occurs abruptly and often results in a lethal outcome. The aim of this study was to retrospectively analyze our experiences of cases of rupture of pseudoaneurysms for providing appropriate therapeutic planning. METHODS: Between 1985 and 1998, we observed ruptures of pseudoaneurysms in 14 of 910 patients with hepatobiliary pancreatic diseases--six after pancreaticoduodenectomy, three after hepatic resection, two after hepatopancreaticoduodenectomy, two after percutaneous transhepatic biliary drainage, and one after gastrojejunostomy. Thirteen of the 14 patients underwent emergency angiography and transcatheter arterial embolization (TAE) or infusion therapies, and one of the 13 patients underwent surgical hemostasis because of incomplete hemostasis with TAE. The other patient, who did not undergo emergency angiography, had surgical hemostasis initially. RESULTS: TAE achieved hemostasis in 11 of 13 patients (85%), but only incomplete hemostasis in the remaining two patients. Of these two patients, one underwent laparotomy, but died of multiple organ failure (MOF) at 6 days after surgical hemostasis. The other died at 1 day after emergency angiography. Ten of 11 patients who obtained complete hemostasis by means of TAE could later be discharged, but one patient died of liver failure, and/or MOF. One patient who underwent laparotomy initially without angiography died of MOF at 43 days after the operation. The onset of rupture of a pseudoaneurysm was a mean of 35.4 days (range 12-76) after surgical or interventional procedures. The warning prodromal symptoms were upper abdominal oppression, nausea, and backache before the rupture of pseudoaneurysms. Fever, leukocytosis. hyperbilirubinemia, anastomotic leak, and intraabdominal abscess were frequent persistent signs in these patients. CONCLUSIONS: If the warning prodromal symptoms appear in patients along with these persistent signs, the impending rupture of pseudoaneurysms should be suspected. Thereafter, a diagnostic angiography should be performed immediately to enable early diagnosis and embolization therapy for rupture of pseudoaneurysms when hemorrhagic episodes appear in these patients. Early detection and immediate embolization might bring about a favorable outcome in patients with hepatobiliary pancreatic diseases who encounter rupture of pseudoaneurysms after surgical and interventional treatments.

Adult↗
PubMed2001

Marked potentiation of activity of beta-lactams against methicillin-resistant Staphylococcus aureus by corilagin.

We found that an extract of Arctostaphylos uva-ursi markedly reduced the MICs of beta-lactam antibiotics, such as oxacillin and cefmetazole, against methicillin-resistant Staphylococcus aureus. We isolated the effective compound and identified it as corilagin. Corilagin reduced the MICs of various beta-lactams by 100- to 2,000-fold but not the MICs of other antimicrobial agents tested. The effect of corilagin and oxacillin was synergistic. Corilagin showed a bactericidal action when added to the growth medium in combination with oxacillin.

Anti-Bacterial Agents↗
PubMed2001

Influenza A virus can undergo multiple cycles of replication without M2 ion channel activity.

Ion channel proteins are common constituents of cells and have even been identified in some viruses. For example, the M2 protein of influenza A virus has proton ion channel activity that is thought to play an important role in viral replication. Because direct support for this function is lacking, we attempted to generate viruses with defective M2 ion channel activity. Unexpectedly, mutants with apparent loss of M2 ion channel activity by an in vitro assay replicated as efficiently as the wild-type virus in cell culture. We also generated a chimeric mutant containing an M2 protein whose transmembrane domain was replaced with that from the hemagglutinin glycoprotein. This virus replicated reasonably well in cell culture but showed no growth in mice. Finally, a mutant lacking both the transmembrane and cytoplasmic domains of M2 protein grew poorly in cell culture and showed no growth in mice. Thus, influenza A virus can undergo multiple cycles of replication without the M2 transmembrane domain responsible for ion channel activity, although this activity promotes efficient viral replication.

Animals↗