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Biomedical subjects

A Itoh

Publications and source records attributed to A Itoh.

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

[A case of imported paratyphoid fever associated with Giardia lamblia and Isospora belli infection].

We report a case of imported paratyphoid fever associated with Giardia lamblia and Isospora belli infection. The patient was a 23-year-old Japanese female with complaints of high grade fever and diarrhea after 10 days traveling to Nepal. Salmonella Paratyphi A was isolated from the blood and fecal cultures on admission and Ciprofloxacin of 200 mg tid was administered for 14 days. Fecal examination revealed cysts of G. lamblia at the same time and metronidazole of 250 mg tid for 7 days was effective for their eradication. During the follow-up studies oocysts of I. belli were found and cotrimoxazole of 960 mg bid for 10 days was effective for their eradication. Fecal examinations on parasites which is rare in Japan such as I. belli are recommended to the cases returning from tropical areas.

Adult↗
PubMed1998

Granulocyte colony-stimulating factor enhances endotoxin-induced decrease in biliary excretion of the antibiotic cefoperazone in rats.

We have recently reported that endotoxin (lipopolysaccharide [LPS]) derived from Klebsiella pneumoniae dramatically decreased the biliary excretion of the beta-lactam antibiotic cefoperazone (CPZ), which is primarily excreted into the bile via the anion transport system, in rats. The present study was designed to investigate the effect of human recombinant granulocyte colony-stimulating factor (G-CSF), which is reported to be beneficial in experimental models of inflammation, on the pharmacokinetics and biliary excretion of CPZ in rats. CPZ (20 mg/kg of body weight) was administered intravenously 2 h after the intravenous injection of LPS (250 microgram/kg). G-CSF was injected subcutaneously at 12 microgram/kg for 3 days and was administered intravenously at a final dose of 50 microgram/kg 1 h before LPS injection. Peripheral blood cell numbers were also measured. LPS dramatically decreased the systemic and biliary clearances of CPZ and the bile flow rate. Pretreatment with G-CSF enhanced these decreases induced by LPS. The total leukocyte numbers were increased in rats pretreated with G-CSF compared to the numbers in the controls, while the total leukocyte numbers were decreased (about 3,000 cells/microliter) by treatment with LPS. Pretreatment with G-CSF produces a deleterious effect against the LPS-induced decrease in biliary secretion of CPZ, and leukocytes play an important role in that mechanism.

Animals↗
PubMed1998

Cardioprotective effect of intravenous nicorandil in patients with successful reperfusion for acute myocardial infarction.

This study was designed to assess the cardioprotective effect of intravenous nicorandil, a potassium channel opener, in preventing reperfusion injury in acute myocardial infarction. Seventy patients were treated with placebo or nicorandil concomitant with reperfusion therapy in a prospective, randomized, double-blind fashion within 6 h after the onset of acute myocardial infarction. Nicorandil was administered before reperfusion as a 2-mg bolus iv injection followed by continuous infusion of 2-6 mg/h for the next 3 h. Thirty-six patients (17 in the placebo group, 19 in the nicorandil group) who demonstrated both complete occlusion of an infarct-related vessel before treatment and successful reperfusion were included in the final analysis. No significant changes in left ventricular ejection fraction were observed between the immediate and chronic phases in each group. In the analysis of regional ventricular function, the placebo group did not show any significant change in regional chord shortening (26.8+/-8.2 vs 24.3+/-7.3%, NS) or hypocontractile perimeter (36.4+/-28.2% vs 28.3+/-24.8%, NS) between immediate and chronic phase left ventriculograms. In contrast, in the nicorandil group, a significant increase in regional chord shortening (21.5+/-11.0% vs 25.8+/-11.3%, p<0.05) and a significant decrease in hypocontractile perimeter (33.3+/-19.6% vs 25.6+/-24.3%, p<0.05) were observed in the chronic phase left ventriculogram. Thus, nicorandil may be a useful adjunctive therapy for preserving myocardial contractile function in patients with acute myocardial infarction undergoing reperfusion therapy.

Acute Disease↗
PubMed1998

A therapeutic strategy to prevent morphine dependence and tolerance by coadministration of cAMP-related reagents with morphine.

Morphine is the most potent opioid analgesic currently available and its use is increasing for treatment of severe pain, however, long-term morphine exposure induces physical dependence/tolerance. Although the mechanisms underlying this phenomenon have not been established, several biochemical changes including intracellular cAMP systems and Ca2+ mobilization have been suggested. To evaluate the contribution of cAMP, we investigated the effects of nefiracetam [N-(2,6-dimethyl-phenyl)-2(2-oxo-1-pyrrolidinyl)acetamide] and phosphodiesterase inhibitors (theophylline, enprofylline and rolipram) on the development of morphine dependence/tolerance. Mice administered morphine (6 or 10 mg/kg, s.c.) twice daily for 5 days, showed withdrawal signs (jumping, diarrhea and body weight loss) after naloxone challenge (5 mg/kg, i.p.), indicating the physical dependence to morphine. Further, the tolerance to antinociceptive effect of morphine was observed in these mice on the tail-flick test. However, coadministration of nefiracetam (5 or 10 mg/kg, p.o.), enprofylline (30 mg/kg, p.o.) and rolipram (0.3 or 1 mg/kg, i.p.) with morphine during the pretreatment period, significantly reduced the withdrawal signs, moreover, the tolerance was significantly attenuated. Acute administration of nefiracetam failed to reduce the withdrawal signs and did not affect the antinociceptive effect of morphine in morphine-naive mice. Theophylline (3 or 10 mg/kg, p.o.) tended to attenuate the development of morphine dependence/tolerance. The present findings suggest that coadministration of compounds which increase cAMP level with morphine may be a useful strategy to attenuate the development of morphine dependence/tolerance in the clinic.

2',3'-Cyclic-Nucleotide Phosphodiesterases↗
PubMed1998

[Clinical and histopathological features of hemangiopericytoma-like tumor of the nasal cavity].

A 65-year-old woman consulted our hospital complaining of left nasal obstruction. On nasal examination, a reddish half round tumor arising from the left nasal septum was found. We removed the tumor together with normal septal mucosa. Histologically, the tumor was diagnosed as a hemangiopericytoma-like tumor. It has been reported that a hemangiopericytoma-like tumor is microscopically distinguished from similar type tumors arising from other sites of the body. The most notable microscopic features of intranasal hemangiopericytoma-like tumors are their uniformity of cells and the absence of nuclear or cytoplasmic pleomorphism with a sheetlike arrangement, and no evidence of varying growth phases or necrosis. This is the second case report of this type of tumor in Japan.

Aged↗
PubMed1998

Usefulness of intraductal ultrasonography in gallbladder disease.

This study was designed to compare intraductal ultrasonography of the gallbladder wall with histopathologic findings and to assess the clinical usefulness of this imaging method in gallbladder disease. Thirty-one gallbladder specimens were examined by intraductal ultrasonography retrospectively. The gallbladder is composed of three layers: an innermost hyperechoic layer, a middle hypoechoic layer, and an outermost hyperechoic layer. The second layer on ultrasonograms corresponds to the muscle layer plus the fibrous tissue of the superficial perimuscular connective tissue layer. In cases in which the thickness of the second layer was 500 microns or less, little fibrous tissue was seen and the second layer was approximately identical to the muscle layer on sonograms. Clinical study was performed on 22 gallbladders. The use of a guidewire through the papilla facilitated intraductal ultrasonographic examination. The intraductal sonographic probe could be inserted into the gallbladder fundus in 13 of 22 cases. In nine unsuccessful cases, technical difficulties were as follows: sharply angulated gallbladder (four cases), stenosis of the gallbladder (two cases), difficulty in transmitting power in the correct direction (three cases). With regard to the area visualized in 13 successful cases, in three cases the area visualized was 100%, in seven cases it was 75%, and three cases it was 50%. Intraductal ultrasonographic images could be obtained in 83.3% (10 of 12) of elevated lesions of the gallbladder. The indications for intraductal ultrasonography will be cases in which an abnormality was detected by transabdominal ultrasonography or other modalities in which the physician does not know whether or not to operate. In conclusion, we defined the intraductal sonographic images of gallbladder wall and clarified the clinical indications for use of this imaging method.

Gallbladder↗
PubMed1998

[Chemotherapy of gastric cancer].

At present curative resection is the only radical treatment for gastric cancer, although recently developed combination chemotherapy shows increased activity in treating locally advanced and metastatic disease. Among several combination regimens, those based on biochemical modulation, such as sequential methotrexate/5-fluorouracil or low-dose CDDP/5-fluorouracil, are thought to provide increased efficacy with decreasing adverse reactions in unresectable gastric cancer. Therefore, a prospective randomized clinical trial comparing the prognosis of patients receiving adjuvant multi-agent chemotherapy with those treated only surgically should be pursued for estimation of the clinical benefit of these agents.

Antineoplastic Agents, Phytogenic↗
PubMed1998

[Usefulness of ECG-gated 99mTc-MIBI myocardial SPECT in the follow-up study of patients with acute myocardial infarction].

To clarify the background of the scintigraphic improvement in non-gated myocardial perfusion imaging for patients with acute myocardial infarction, we performed serial ECG-gated 99mTc-MIBI myocardial SPECT in 17 patients with acute myocardial infarction (AMI) receiving successful reperfusion therapy. ECG-gated myocardial SPECT and left ventriculography were performed at 1 week (acute phase) and 1 month (subacute phase) after the onset of AMI. Regional %uptake (regional count x 100/maximal count) was determined for each of 8 myocardial segments of the Bull's eye map. We analyzed the data in 53 AMI segments out of total 136 myocardial segments, on the non-gated (NG), end-diastolic (ED), and end-systolic (ES) images. In addition, the delta %uptake (%uptake in subacute phase--%uptake in acute phase) was also determined as an index representing the improvement of myocardial tracer uptake on each image. In 17 segments (group A) with wall motion recovery assessed by serial left ventriculography, the %uptake on the NG image was significantly improved (61.6 +/- 10.0 to 75.7 +/- 10.1, p < 0.0001). However, in 36 segments (group B) without wall motion recovery, the change of %uptake on the NG image was small. There was no significant change in the %uptake on the ED image in groups A and B. On the contrary, the %uptake on the ES image showed a significant increase in group A (58.4 +/- 11.8 to 68.9 +/- 11.8, p < 0.001), but did not in group B. Thus, this change on the ES image reflects the wall motion recovery. Furthermore, in group A, there was a significant correlation between the delta %uptake on the NG image and those on the ES image (p < 0.02), but was not between those on the NG and the ED images. Thus, the change in the %uptake on the NG image was more related to those on the ES image which is more affected by the change in regional wall motion than those on the ED image which reflects improved myocardial perfusion. These results suggest that ECG-gated myocardial 99mTc-MIBI SPECT is more useful to assess the serial change in myocardial perfusion and contraction than the conventional non-gated SPECT in the follow-up study of patients with AMI.

Aged↗
PubMed1997

Abnormalities of sensory and memory functions in mice lacking Bsg gene.

Basigin is a highly glycosylated transmembrane protein belonging to the immunoglobulin superfamily. We used mutant mice lacking the basigin gene (Bsg) to investigate its involvement in learning and memory. Mutations were generated by the gene targeting method. Various kinds of learning and memory tasks were performed in mutant, hetero and wild type mice. The mutant mice showed worse performance than the wild and hetero mice in the Y-maze task, which assesses short-term memory, and in the water finding task, which examines latent learning, without any motor dysfunction. Moreover, the mutant mice showed less acclimation in the habituation task compared with the wild-type mice. The mutant mice were also more sensitive to electric foot-shock. These findings are consistent with the expression profile of basigin in the central nervous system. Thus, basigin may play an important role in learning and memory as well as in the sensory functions.

Animals↗
PubMed1997

Effects of metrifonate on memory impairment and cholinergic dysfunction in rats.

Metrifonate is an organophosphorous compound that has been used in the treatment of schistosomiasis. In this study, we investigated the effects of metrifonate on the impairment of learning and on central cholinergic dysfunction in scopolamine-treated and basal forebrain-lesioned rats. Oral administration of metrifonate (5.0-15.0 mg/kg) ameliorated the scopolamine- and basal forebrain. lesion-induced learning impairment in the water maze and passive avoidance tasks. Metrifonate (50 and 100 mg/kg) also significantly increased extracellular acetylcholine levels but decreased choline levels in the cerebral cortex of the basal forebrain-lesioned rats. The basal forebrain lesion decreased the cholinesterase activity in the cerebral cortex, and metrifonate (100 mg/kg) further reduced the cholinesterase activity. However, cholinesterase inhibition was not observed at the dose that ameliorated learning impairments. These results indicated that metrifonate ameliorated the impairment of learning in both scopolamine-treated and basal forebrain-lesioned rats by not only increasing extracellular acetylcholine levels by inhibiting cholinesterase, but also by undefined other mechanism(s). This finding suggests the usefulness of metrifonate for the therapy of Alzheimer's disease.

Acetylcholine↗
PubMed1997

Results of a consecutive series of patients receiving only antiplatelet therapy after optimized stent implantation. Comparison of aspirin alone versus combined ticlopidine and aspirin therapy.

BACKGROUND: Previous studies have shown that stents can be inserted in coronary arteries of patients who are subsequently treated safely with antiplatelet therapy only (ticlopidine and/or aspirin) with a low incidence of stent thrombosis, provided that stent expansion is adequate and there are no other flow-limiting lesions present. However, it is unknown whether ticlopidine combined with aspirin is superior to aspirin alone in preventing stent thrombosis. METHODS AND RESULTS: From March 1993 through July 1995, 801 consecutive patients assigned to receive either aspirin therapy alone (ASA, 264 patients, 348 lesions) or a combination of ticlopidine and aspirin (TIC-ASA, 537 patients, 737 lesions) after a successful stent insertion, in most accomplished with intravascular ultrasound guidance, were evaluated retrospectively. At 1 month, there was no difference in the ASA group compared with the TIC-ASA group in the rate of any stent thrombosis (1.9% versus 1.9%; P = 1), subacute stent thrombosis (1.9% versus 1.3%; P = .5), cumulative major adverse clinical events (1.9% versus 2.0%; P = 1), and peripheral vascular complications (0.5% versus 0.2%; P = .3). Medication side effects that required termination of antiplatelet therapy occurred only in 1.9% of patients in the TIC-ASA group (P = .04). CONCLUSIONS: At 1-month clinical follow-up, stent thrombosis and other adverse clinical outcomes were not significantly different between the ASA and TIC-ASA groups. Medication side effects occurred only in patients treated with ticlopidine. These results provide further evidence of the safety of treatment with antiplatelet therapy only after optimal stent implantation and support the efficacy of aspirin alone in preventing stent thrombosis.

Angioplasty, Balloon↗
PubMed1997

FGF-1 and FGF-7 induce distinct patterns of growth and differentiation in embryonic lung epithelium.

Fibroblast growth factors (FGFs) and receptors (FGFRs) are expressed in the developing lung and appear to be major regulators of lung growth and differentiation. By using mesenchyme-free lung epithelial cultures we show that FGF-1 (aFGF) and FGF-7 (KGF) produce different effects in the developing lung. FGF-1 stimulates epithelial proliferation that results in bud formation (branching), while FGF-7 promotes epithelial proliferation that leads to formation of cyst-like structures. In addition, FGF-7 stimulates epithelial differentiation, stimulating expression of SP-A and SP-B mRNA throughout the explant, and inducing formation of focal areas of highly differentiated cells. The FGF-1 effects on differentiation are limited to induction of surfactant protein SP-B mRNA at the tips of the explant. The FGF-induced patterns of growth appear to correlate with the distribution of epithelial FGFRs mRNAs; FGFR-2 IIIb (KGFR) is diffusely expressed in the day 11 lung epithelium, while FGFR-4 appears in distal but not in proximal sites. We propose that cyst-like structures may result from FGF-7 binding to the uniformly distributed FGFR-2-IIIb. Lung bud formation may be regulated by FGF-1 and/or other ligands binding to FGFR-2 and a distally located FGFR, such as FGFR-4, leading to an increasing binding and activation of FGFRs at the tips of the explant. Thus, in the embryonic lung epithelium, growth effects of FGFs appear to be dependent on location of FGFRs, while effects on differentiation are ligand-dependent.

Animals↗
PubMed1997

Mapping cell wall polysaccharides of living microbial cells using atomic force microscopy.

Functionalized atomic force microscope tips were used to sense specific forces of interaction between ligand-receptor pairs and to map the positions of polysaccharides on a living microbial cell surface. Gold-coated tips were functionalized with concanavalin A using a cross-linker with a spacer arm of 15.6 A. It was possible to measure the binding force between concanavalin A and mannan polymers on the yeast (Saccharomyces cerevisiae) cell surface. This force ranged from 75 to 200 pN. The shape of the force curve indicated that the polymers were pulled away from the cell surface for a fairly long distance that sometimes reached several hundred nanometres. The distribution of mannan on the cell surface was mapped by carrying out the force measurement in the force volume mode of atomic force microscopy (AFM). During the measurement, the maximum cantilever deflection after contact between the tip and the sample was kept constant at 10 nm using trigger mode to keep the pressing force on the sample surface as gently as possible at a force of 180 pN. This regime was used to minimize the non-specific adhesion between the tip and the cell surface. Specific molecular recognition events took place on specific areas of the cell surface that could be interpreted as reflecting a non-uniform distribution of mannan on the cell surface.

Cell Membrane↗
PubMed1997

Intraductal ultrasonography in diagnosing tumor extension of cancer of the papilla of Vater.

BACKGROUND: Intraductal ultrasonography is clinically useful in assessing various pancreatobiliary diseases. This study was carried out to evaluate the usefulness of intraductal ultrasonography in diagnosing tumor extension of cancer of the papilla of Vater. METHODS: Thirty-two patients with cancer underwent intraductal ultrasonography. According to the spatial relationship between the tumor echo and the hypoechoic layers representing Oddi's muscle layer or the duodenal muscularis propria layer, the images were classified into four grades. We attempted to diagnose tumor extension using this grading system. Lymph nodes measuring over 10 mm were evaluated as involved. Findings were compared with postoperative histopathologic findings classified as follows: d0, tumor limited to Oddi's muscle layer; d1, tumor invading the duodenal submucosal layer; d2, tumor invading the duodenal muscularis propria layer; and panc(+), tumor invading the pancreas. RESULTS: Diagnostic accuracy rate was 100% (6 of 6) in d0 cases, 92.3% (12 of 13) in d1 cases, 100% (1 of 1) in a d2 case, and 75% (9 of 12) in panc(+) cases. Overall accuracy rate was 87.5% (28 of 32). In assessing lymph node metastases, sensitivity was 66.7% (6 of 9) and specificity was 91.3% (21 of 23). CONCLUSION: Intraductal ultrasonography examination is useful in diagnosing tumor extension of cancer of the papilla of Vater.

Adult↗
PubMed1997

Effects of metrifonate on impairment of learning and dysfunction of cholinergic neuronal system in basal forebrain-lesioned rats.

Several studies have indicated the possibility of using cholinesterase (ChE) inhibitors as therapeutic drugs for Alzheimer's disease. Metrifonate (MTF) is an organophosphorus compound that has been used in the treatment of schistosomiasis. In this study, we investigated the effects of MTF on the impairment of learning and memory, decreased ChE activity and extracellular acetylcholine (ACh) levels in basal forebrain (BF)-lesioned rats. The oral administration of MTF improved the BF-lesion-induced impairment of performance on passive avoidance task. Further, MTF reduced ChE activity in the cerebral cortex. In vivo brain microdialysis studies showed that MTF significantly increased the release of ACh, but decreased that of choline (Ch) in the cerebral cortex of BF-lesioned rats. These results indicated that MTF ameliorates the impairment of performance on passive avoidance task in BF-lesioned rats by increasing the extracellular ACh levels by inhibiting ChE. This suggested that MTF may be useful as a therapeutic drug for Alzheimer's disease.

Acetylcholine↗
PubMed1997

T-lymphocytes regulate genetically determined airway hyperresponsiveness in mice.

Airway hyperresponsiveness (AHR) is a hallmark of asthma and a heritable polygenic trait in the mouse. In the mouse, candidate gene products of hematopoietic origin implicated in asthma mapped to the regions of the previously defined quantitative trait loci. Since hematopoietic cells have been implicated in the pathogenesis of asthma, we evaluated the role of hematopoietic cells in general and T cells specifically in the genetic modulation of native airway responsiveness in mice. Here, with the use of bone marrow transplantation, anti-T-cell monoclonal antibody treatment and T-cell transfer, we demonstrate that intrinsic non-atopic AHR is mediated by T lymphocytes. Our data support the novel concept that, in the absence of identified environmental influences, T cells enhance genetically determined airway responsiveness.

Adoptive Transfer↗