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Biomedical subjects

M Ikeda

Publications and source records attributed to M Ikeda.

At least 145 records · Page 8Linked to original sources
PubMed2001

Inhibitory effect of pentalenolactone on vascular smooth muscle cell proliferation.

The effect of pentalenolactone, an inhibitor of glyceraldehyde-3-phosphate dehydrogenase, on rat vascular smooth muscle cell proliferation was studied. Addition of pentalenolactone together with serum to quiescent cells dose-dependently inhibited cell proliferation and DNA synthesis. This inhibition was not associated with cell death. When quiescent cells were stimulated with serum and then treated with pentalenolactone, the inhibitory effect on the DNA synthesis declined gradually. A similar result was obtained when PD 98059 (2'-amino-3'-methoxyflavone), an inhibitor of extracellular signal-regulated kinase1/2 (ERK1/2) kinase (MEK1/2), was added to the cells after serum stimulation. Pentalenolactone inhibited serum or protein kinase C activator (phorbol 12,13-dibutyrate)-induced phosphorylation of ERK1/2 and MEK1/2. In contrast, pentalenolactone had little effect on platelet-derived growth factor receptor autophosphorylation. Taken together, these results indicate that pentalenolactone inhibits vascular smooth muscle cell proliferation, and that this inhibition appears to be mediated by inhibition of the ERK1/2 cascade.

3T3 Cells↗
PubMed2001

Inhibitory effects of ruthenium red on inositol 1,4, 5-trisphosphate-induced responses in rat megakaryocytes.

The effects of ruthenium red (RR) on inositol 1,4,5-trisphosphate (InsP(3))-induced responses were studied in rat bone marrow megakaryocytes with the patch-clamp whole-cell recording technique in combination with fura-2 microfluorometry. Internal application of InsP(3) (100 microM) increased intracellular Ca(2+) concentration ([Ca(2+)](i)) and activated the Ca(2+)-dependent K(+) current. Administering InsP(3) together with RR (100-500 microM) inhibited InsP(3)-induced responses (both Ca(2+) and current responses) in a dose-dependent fashion. Pretreatment of megakaryocytes with extracellular RR (50 microM) also inhibited InsP(3)-induced responses. Intracellular and extracellular application of RR reduced ADP-induced increases in [Ca(2+)](i). In contrast, in isolated single pancreatic acinar cells, RR had no effect on InsP(3)-induced responses. Taken together, these results suggest that the site of the inhibitory action of RR is at the InsP(3) receptor, or its closely associated proteins. In addition, we have shown that RR is a useful pharmacological tool with which to examine the InsP(3)-mediated responses of megakaryocytes.

Adenosine Diphosphate↗
PubMed2001

Brain Abeta amyloidosis in APPsw mice induces accumulation of presenilin-1 and tau.

APPsw transgenic mice (Tg2576) overproducing mutant amyloid beta protein precursor (betaAPP) show substantial brain Abeta amyloidosis and behavioural abnormalities. To clarify the subsequent abnormalities, the disappearance of neurons and synapses and dystrophic neurite formation with accumulated proteins including hyperphosphorylated tau were examined. Tg2576 demonstrated substantial giant core plaques and diffuse plaques. The number of neurons was significantly decreased in the areas containing the amyloid cores compared with all other areas and corresponding areas in non-transgenic littermates in sections visualized by Nissl plus Congo red double staining (p<0.001). The presynaptic protein alpha-synuclein and postsynaptic protein drebrin were also absent in the amyloid cores. betaAPP and presenilin-1 were accumulated in dystrophic neurites in and around the core plaques. Tau phosphorylated at five independent sites was detected in the dystrophic neurites in the amyloid cores. Thus, the giant core plaques replaced normal brain tissues and were associated with subsequent pathological features such as dystrophic neurites and the appearance of hyperphosphorylated tau. These findings suggest a potential role for brain Abeta amyloidosis in the induction of secondary pathological steps leading to mental disturbance in Alzheimer's disease.

Alzheimer Disease↗
PubMed2001

Pedunculated hemangioma in the right ventricle.

We report a rare case of right ventricular hemangioma. In an asymptomatic 56-year-old man, echocardiography as a part of medical checkup demonstrated a pedunculated tumor, 1.0 x 1.3 x 1.5 cm, arising from the free wall of the right ventricle. No findings were seen of a feeding artery to the tumor or vascular blush in preoperative coronary angiography. Successful resection was done through right atriotomy under total cardiopulmonary bypass. The histological examination revealed capillary hemangioma. The postoperative clinical course was uneventful, but requires careful follow-up for possible coronary cardiac fistula. This is the fifth case of right ventricular hemangioma, to our knowledge, ever reported in Japan.

Heart Neoplasms↗
PubMed2001

Experiences on persistent organic pollutants under the Law concerning the Examination and Regulation of Manufacture, etc. of Chemical Substances, Japan, with references to biodegradation and bioaccumulation.

OBJECTIVES: The purpose of this report is to outline current regulations to control chemical environmental pollution in Japan, with special references to internationally defined 12 persistent organic pollutants (POPs). MATERIALS: Law concerning the Examination and Regulation of Manufacture, etc. of Chemical Substances [(LERCS); enacted in 1973] and related administrative activities of monitoring of the environment in Japan. RESULTS: Among the existing chemicals identified by the 1972 Chemicals Inventory, LERCS designates aldrin, chlordanes, DDT, dieldrin, endrin, HCB, PCBs, poly(Cln; n = 3 or more)-chlorinated naphthalene (PCNs) and bis(tributyltin) oxide (TBTO) as Class 1 specified chemical substances which are under strict regulation, such as prohibition of production, import, or use in principle. In addition LERCS designates 23 Class 2 specified chemical substances (including 13 tributyltin and seven triphenyltin compounds) for which notification of scheduled and past production, compliance with technical guidelines and compliance with labeling standards is requested. When compared with the 12 POPs, the designation covers most of them except for mirex and toxaphene, which have never been used in Japan. The regulation has been effective in reducing substantially the levels of the designated chemical substances (and therefore the 12 POPs except for dioxins and furans) in the general environment in Japan. Efforts are currently focused under a newly enacted law to reduce the emission of the two non-intentionally produced pollutants of dioxins and furans, especially from city waste incinerators, so that emission in 2002 should be 10% of that in 1997. CONCLUSION: Regulations to control chemical emissions have been effective in reducing POPs levels in the environment in Japan, and further efforts have been made under a new law to reduce the emission of dioxins, furans and co-planar PCBs.

Chemical Industry↗
PubMed2001

Urinary bromide levels probably dependent to intake of foods such as sea algae.

The purpose of the present study is to examine if the bromide (Br) level in urine (Br-U) varies substantially among adult general populations of either sex or of different dietary habits. For this purpose, morning spot urine samples (about 50 per group) were collected from six groups of people, i.e., one group each of men and women in a city in Japan (thus two groups in Japan) and one group each of women in two urban and two rural areas in central and northeast China (four groups in China). The samples were analyzed for Br by ECD-gas chromatography after derivatization to methyl bromide. Br-U essentially followed a normal distribution. Whereas there was only a marginal difference in Br-U between men (7.7 +/- 2.5 mg/L as an arithmetic mean and arithmetic standard deviation) and women (8.1 +/- 2.9 mg/L) in Japan, and no difference between the urban (2.3 +/- 0.8 mg/L) and rural women (2.6 +/- 1.1 mg/L) in China, the difference between Japanese (8.1 +/- 2.9 mg/L) and Chinese women (2.3 +/- 0.8 mg/L for two cities and 2.6 +/- 1.1 mg/L for two villages) was substantial. A literature survey suggested variation in dietary habits, especially that in sea algae intake, is a possible factor affecting the observed difference in Br-U between the two ethnic groups. Contribution of Br in cereals after fumigation with, e.g., methyl bromide, was also thought to be possible. The implication of difference in background Br-U levels is discussed in relation to biological monitoring of exposure to Br-containing industrial chemicals, such as 1- and 2-bromopropane.

Adult↗
PubMed2001

Effect of transketolase modifications on carbon flow to the purine-nucleotide pathway in Corynebacterium ammoniagenes.

Transketolase, one of the enzymes in the nonoxidative branch of the pentose phosphate pathway, operates to shuttle ribose 5-phosphate and glycolytic intermediates together with transaldolase, and might be involved in the availability of ribose 5-phosphate, a precursor of nucleotide biosynthesis. The tkt and tal genes encoding transketolase and transaldolase, respectively, were cloned from the typical nucleotide- and nucleoside-producing organism Corynebacterium ammoniagenes by a PCR approach using oligonucleotide primers derived from conserved regions of each amino acid sequence from other organisms. Enzymatic and molecular analyses revealed that the two genes were clustered on the genome together with the glucose 6-phosphate dehydrogenase gene (zwf). The effect of transketolase modifications on the production of inosine and 5'-xanthylic acid was investigated in industrial strains of C. ammoniagenes. Multiple copies of plasmid-borne tkt caused about tenfold increases in transketolase activity and resulted in 10-20% decreased yields of products relative to the parents. In contrast, site-specific disruption of tkt enabled both producers to accumulate 10-30% more products concurrently with a complete loss of transketolase activity and the expected phenotype of shikimate auxotrophy. These results indicate that transketolase normally shunts ribose 5-phosphate back into glycolysis in these biosynthetic processes and interception of this shunt allows cells to redirect carbon flux through the oxidative pentose pathway from the intermediate towards the purine-nucleotide pathway.

Amino Acid Sequence↗
PubMed2001

Detection of subtle pulmonary disease on CR chest images: monochromatic CRT monitor vs color CRT monitor.

To clarify the diagnostic efficacy of color soft-copy computed radiographic (CR) images of the chest in the detection of subtle pulmonary abnormalities. Twenty observers compared 87 soft-copy CR images on four types of CRT monitor (nonmagnified monochromatic CRT, magnified monochromatic CRT, nonmagnified color CRT, and magnified color CRT). Of 87 test images, 45 (including two identical sets of 12 images to test intraobserver variability) were abnormal and 42 (including two identical sets of 12 images) were normal. Of the 45 abnormal images, 15 showed subtle abnormalities, 15 showed mild abnormalities, and 15 showed obvious abnormalities. In the receiver operating characteristic (ROC) analyses, there were no statistically significant differences among the four types of CRT display formats in the detection of subtle abnormalities. Color CRT monitors can replace monochromatic CRT monitors without any loss in the ability to detect subtle interstitial lung disease.

Adult↗
PubMed2001

Distribution of cerebral cortical lesions in Pick's disease with Pick bodies: a clinicopathological study of six autopsy cases showing unusual clinical presentations.

We investigated six Japanese autopsy cases of Pick's disease with Pick bodies (PDPB) both clinically and pathologically, and examined the distribution of their cerebral cortical lesions using hemisphere and/or bisphere specimens. The lesions were classified into three categories (slight, moderate, and severe). Two patients with a clinical diagnosis of primary progressive apraxia and of slowly progressive aphasia had speech apraxia as their initial signs, and the other two patients were suspected as having Alzheimer's disease, with the clinical diagnosis of the remainder two patients being presenile dementia and depression, respectively. Extrapyramidal signs, believed to be rare in PDPB, were present in four patients. Severe lesions were multicentrically present in the cerebral cortices of all six cases. In two patients with speech apraxia, severe lesions were seen in the primary motor area, which generally has not been regarded as an "atrophic center" in Pick's disease. Furthermore, in a patient with depression, severe lesions were more widespread in the convexity than in the orbital region of the frontal lobe. The parietal lobes, including the postcentral gyrus usually believed to be spared in Pick's disease, were severely involved in three patients. We postulate that the clinical features of PDPB have a much wider spectrum than previously believed. In addition, we believe that the distribution of the cerebral cortical lesions in PDPB is more widespread than previously assumed, and that clinical manifestations of PDPB depend to some extent on the topographic distribution of the cerebral cortical lesions.

Aged↗
PubMed2001

Use of solvents in industries in Korea: experience in Sinpyeong-Jangrim industrial complex.

OBJECTIVES: To identify the most popular solvent and typical type of solvent work among solvent-using workplaces in Korea. METHODS: In practice, 862 solvent-using workshops in Sinpyeong-Jangrim industrial complex in Pusan were investigated in a 2-year period from March 1995 to February 1997. Solvent vapors in the breathing zone of workers were collected by personal sampling with charcoal tubes. The exposed charcoal was extracted with carbon disulfide, and the solvents in the extract were analyzed by flame ionization detector-equipped gas chromatography (FID-GC). RESULTS: Solvents were used in painting, glue application, cleaning, printing and solvent-mixing workshops in decreasing order of popularity. Toluene was the most frequently measured solvent. In the five types of solvent work, acetone, hexane, methyl ethyl ketone, methyl isobutyl ketone, tetrachloroethylene, trichloroethylene and xylenes were also used frequently. CONCLUSIONS: Toluene was identified as the most frequently used solvent in solvent works in Korean manufacture industries in the late 1990s. Eight types of solvent were popularly used in five popular types of solvent work. These trends are very similar to the cases reported for industries in Japan.

Adhesives↗
PubMed2001

Pulmonary carcinogenesis induced by ferric nitrilotriacetate in mice and protection from it by Brazilian propolis and artepillin C.

In experiments using the renal carcinogen ferric nitrilotriacetate (Fe-NTA) in male ddY mice, primary pulmonary cancers were also induced in bronchiolar and alveolar tissues. 4-Hydroxy-2-nonenal (4-HNE) and 8-hydroxy-2'-deoxyguanosine (8-OHdG), products of oxidative processes, increased in bronchiolar and alveolar cells after administration of Fe-NTA. These substances disappeared after oral administration of propolis or artepillin C, as shown histochemically, and correlated with an anticancer prophylactic effect of propolis and artepillin C. From our investigation, lipid peroxidation seems to play an important role in pulmonary carcinogenesis. Malignant progression from adenoma of bronchiolar or alveolar origin to malignant tumors has been proposed to involve a stepwise transformation. In our study, adenomas developed into adenocarcinomas and large cell carcinomas after treatment with Fe-NTA. In contrast, after oral administration of propolis or artepillin C, adenomas did not progress to carcinomas. Instead of developing into large cell cancers, as induced by Fe-NTA in control mice, adenomas showed remarkable proliferation of macrophages and local anti-oxidant activity after treatment with either propolis or artepillin C. Propolis and artepillin C therefore appear to inhibit lipid peroxidation and the development of pulmonary cancers.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed2001

Acute reversible renal failure with macroscopic hematuria in Henoch-Schönlein purpura.

A Japanese girl aged 5 years 4 months developed macroscopic hematuria and acute renal failure (ARF) 8 days before the appearance of purpura rash. A renal biopsy undertaken during the acute phase of illness revealed many red blood cells in the tubular lumina with no apparent glomerular lesions. ARF showed improvement without dialysis therapy. A second renal biopsy was performed 2.5 months later because of the prolonged proteinuria and hematuria. Sclerotic change and crescent formation were demonstrated in 30% and 20% of glomeruli, respectively. Red blood cell casts in the tubular lumina were completely resolved. It is likely that the tubular change was involved in the development of ARF at the onset of illness. Although ARF during or after episodes of macroscopic hematuria has been observed in IgA nephropathy, it may occur as an uncommon complication in Henoch-Schönlein nephritis, which is a common glomerulonephritis in children.

Acute Kidney Injury↗
PubMed2001

Antibacterial action of tryptanthrin and kaempferol, isolated from the indigo plant (Polygonum tinctorium Lour.), against Helicobacter pylori-infected Mongolian gerbils.

We evaluated the effect of tryptanthrin and kaempferol, both isolated from Polygonum tinctorium Lour., against Helicobacter pylori colony formation in vitro and in H. pylori-infected Mongolian gerbils. H. pylori suspension was mixed with solution of tryptanthrin and/or kaempferol and placed onto agar plates. These plates were incubated at 37 degrees C, under 10% CO2 for 5 days, and the H. pylori colonies were counted. For the in vivo experiment, Mongolian gerbils were inoculated with H. pylori ATCC 43504 orally. After 4 weeks, the infected gerbils were given tryptanthrin and/or kaempferol, administered orally, twice a day for 10 days. The animals were killed and the number of live H. pylori in their stomachs was determined. In vitro both tryptanthrin and kaempferol significantly decreased the numbers of H. pylori colonies a dose-dependent manner. An additive effect on colony formation was observed with the combined use. In the in vivo experiment, oral administration of tryptanthrin and/or kaempferol significantly decreased the numbers of colonies in the gerbils' stomachs. We concluded that tryptanthrin and kaempferol were effective against H. pylori in vivo.

Animals↗
PubMed2001

Splenic and pulmonary metastases from renal cell carcinoma: report of a case.

We report herein the case of a patient in whom pulmonary and splenic metastases from renal cell carcinoma (RCC) were successfully treated by surgical excision. A 69-year-old man who underwent left nephrectomy for RCC 17 months before was suspected to have a pulmonary metastasis based on computed tomography (CT) findings. Partial resection of the left lower lobe was performed with thoracoscopic assistance. However, 4 months later, a splenic tumor, 6 cm in diameter, was detected by CT and ultrasonography, and a splenectomy was performed. Histologically, both resected specimens were diagnosed as metastasis from RCC. A second pulmonary metastasis of the left upper lobe was resected 4 years 8 months later. The patient was in good health when last seen 11 months after his last operation. Malignant neoplasms rarely metastasize to the spleen and most cases are found at autopsy, or feature multiple distant metastases. Only four other cases of splenic metastases from RCC have been reported. The prognosis associated with splenic metastasis is favorable when only a solitary lesion exists.

Aged↗
PubMed2001

An obstructed venous aneurysm presenting as an abdominal mass: report of a case.

We report herein the case of a 32-year-old woman found to have a venous aneurysm originating from the ovarian vein. The patient presented with a 9-cm abdominal tumor, and surgery was performed under the preoperative diagnosis of a mesenteric cyst. The tumor was easily ablated from the mesentery and resected with the right ovarian artery and vein. Histologically, the wall of the cyst showed the structure of a vein, and the diagnosis of a venous aneurysm was made. This disease is difficult to diagnose preoperatively when a patient presents with no symptoms other than a palpable mass, or when the lumen is obstructed by thrombus. This report serves to demonstrate that a venous aneurysm should be considered in the differential diagnosis of an asymptomatic abdominal mass.

Adult↗
PubMed2001

Three-dimensional image display without special eyeglasses: observation of magnetic resonance angiography using the stereoscopic liquid crystal display.

The authors have developed a new stereoscopic liquid crystal display that provides real-time 3-dimensional image viewing without special eyeglasses. The device consists of 3 major parts: (1) an image display composed of a 10.4-inch color liquid crystal plate with a resolution of 640 x 480, (2) an automatic head tracking system, and (3) a special backlight unit for the right and left eyes. Eight radiologists interpreted 60 cases of magnetic resonance angiography (29 cases of cerebrovascular disease and 31 normal cases) to compare film display and the liquid crystal display (ie, pseudo 3-dimensional display and true 3-dimensional display). Using a continuously distributed scale ranging from 0% to 100%, the observers ranked their confidence levels in determining the presence or absence of steno-occlusive disease, aneurysm, and arteriovenous malformation (AVM) and their locations. For statistical evaluation, receiver operating characteristic (ROC) analysis and Brier score were used. For detecting AVM, film reading showed a significantly higher value in the area under the binormal ROC curve (Az) than did pseudo-3-dimensional display (P < .05). Excluding this, however, no significant difference existed in Az values among the 3 viewing methods. Also, there was no significant difference in Brier score between not only the stereoscopic view and nonstereoscopic view groups, but also the senior and junior groups. Subjective estimation of true 3-dimensional display showed that vessels were more distinguishable with less eye fatigue compared with stereoscopic film reading. The stereoscopic liquid crystal display provided almost equal efficacy to film reading; however, the short optimum distance for observation and the low resolution should be improved.

Cerebrovascular Disorders↗
PubMed2001

Expression of lysosome-associated membrane proteins in human colorectal neoplasms and inflammatory diseases.

The lysosome-associated membrane proteins (LAMPs)-1 and -2 are major constituents of the lysosomal membrane. These molecules are known to be among the most glycosylated proteins of several types of cells and cancer cells, and their expression in cancer cells is marked by a distinct difference in the structures of the oligosaccharides as compared to nonmalignant cells. We analyzed by immunohistochemistry the intensity and distribution of LAMP-1 and LAMP-2 in 9 human colorectal cancer cases and in 16 control cases, including inflammatory diseases (diverticulitis, ulcerative colitis, and Crohn's disease). LAMP proteins were expressed more intensely in the epithelium of colorectal neoplasms than in normal mucosa (P < 0.05), and no significant differences were found between adenoma and cancer cells (P > 0.05) in the same tissue section. Further, in sites of inactive inflammatory diseases and nonneoplastic areas in cancer specimens, no significant increases in epithelial LAMP proteins were observed, even in the proliferative zone of the lower crypt epithelium. Northern blot analysis showed increased expression of LAMP-1 and LAMP-2A in two of three colorectal cancers examined and increased LAMP-2B in all three cancers. Our findings suggest that LAMPs are related to neoplastic progression, but there is no direct association between the expression of LAMP molecules and cell proliferation.

Adenocarcinoma↗