Search PubMed⌕ Search

Biomedical subjects

M Shimada

Publications and source records attributed to M Shimada.

At least 343 records · Page 19Linked to original sources
PubMed1997

Localization of 2',5'-oligoadenylate synthetase and the enhancement of its activity with recombinant interferon-alpha A/D in the mouse brain.

Although the expression of 2',5'-oligoadenylate synthetase (2-5AS) is induced by interferon (IFN), low constitutive levels can be detected in animals that have not been treated with IFN. In order to clarify which cells express 2-5AS in the mouse brain, the distribution of this enzyme in the brains of both normal healthy mice and mice treated with recombinant human IFN-alpha A/D was studied by Western blotting and immunohistochemistry, using a specific monoclonal antibody. On the Western blots, the antibody to 42-kD 2-5AS reacted slightly with extracts from the telencephalon, cerebellum, diencephalon, and medulla oblongata of normal mouse brain. 42-kD 2-5AS was predominantly found in the ependymal cells and epithelium of the choroid plexus, and to a lesser degree in neurons and glial cells. Injection of recombinant human IFN-alpha A/D into the left lateral ventricle enhanced the activity of the enzyme in the telencephalon, cerebellum, diencephalon, and medulla oblongata, but did not change the immunohistochemical localization of the enzyme. Direct injection of the IFN into the cortex of the telencephalon enhanced the activity of 2-5AS in all parts of the brain and immunoreactivity was observed in the neurons and glial cells surrounding the injection site. These data indicate that 42-kD 2-5AS activity in the mouse brain is enhanced by the injection of recombinant human IFN-alpha A/D either into the left lateral ventricle or cortex of the telencephalon. Expression of 42-kD 2-5AS in ependymal cells and epithelium of the choroid plexus may prevent viral infections in the brain.

2',5'-Oligoadenylate Synthetase↗
PubMed1997

Epidermal growth factor binding sites in the mouse exocrine and endocrine pancreas shown by in vivo quantitative microautoradiography and confocal laser scanning microscopy.

Microautoradiography at 3, 6 and 15 min after intravenous injection of 125I-EGF was used to investigate the distribution of epidermal growth factor (EGF) binding sites in the pancreas of normal male mice. The autoradiographs were observed by confocal laser microscopy, which allows the quantification of silver grains. The results demonstrated that both endocrine and exocrine pancreatic cells exhibited substantial specific binding of 125I-EGF. The highest level of EGF binding was found in the duct cells of the exocrine pancreas followed by the acinar cells. The cells of the islets of Langerhans also showed substantial specific binding of 125I-EGF though the binding level was lower than that of the exocrine pancreas. In the control experiments, mice were injected with 125I-EGF and various amounts of unlabeled EGF.

Animals↗
PubMed1997

Mass-screening of neuroblastoma using urine from infants by high-performance liquid chromatographic method: results of first (6th month) and second (14th month) screening.

To detect neuroblastoma in early stages, mass-screening of this tumor was carried out by HPLC method using the urine of six-month-old infants. Screening began in April, 1981, and a total of 42 cases were detected by December, 1994. The incidence of detection was about 1:5,000 babies tested. All of these patients have survived without relapses except one, who died of surgical complications. Nevertheless, tumors developed at later stages in 14 cases from the group which resulted negative at the 6-month screening. To determine whether such tumors could be detected by a second check, a 14-month screening was carried out, beginning in April, 1991. By December, 1994, 3 patients with neuroblastoma were found among 41,809 babies tested, and were subsequently treated. While one of these three patients was not screened at 6 months, the other two had shown approximate cut-off values in urinary VMA as well as HVA at their 6-month screening. Therefore, if the tumors had already existed at the 6-month screening, and had grown gradually until the second check at 14 months, at least some of these tumors were of the late-onset variety and could have been detected at an earlier stage.

Chromatography, High Pressure Liquid↗
PubMed1997

Extranodal connective tissue invasion and the expression of desmosomal glycoprotein 1 in squamous cell carcinoma of the oesophagus.

We investigated extranodal connective tissue involvement (ECTI) in 39 patients with oesophageal carcinoma. Both the primary tumour and ECTI were immunohistochemically examined using the monoclonal antibody 32-2B for desmosomal glycoprotein 1 (DG1). Connective tissue carcinoma deposits were identified as cells within small lymph nodes, as lymphatic or venous vessel invasion or as widespread invasion beyond the capsule of metastatic lymph nodes. These histological findings were present in at least one area in 20 of 39 patients (51.3%). DG1 immunostaining intensity by tumour was graded as DG1 (++), DG1 (+) or DG1 (-). DG1 (+) or DG1 (-) primary tumours demonstrated lymph node metastases and ECTI more frequently than DG1(++) tumours (P<0.05). Among 17 patients in whom DG1 immunohistochemistry was performed on ECTI, there were three DG1(++), five DG1(+) and nine DG1(-) patients. The DG1 expression of ECTI was equal to or less intense than the primary tumour. These results indicate that reduction or loss of DG1 expression may promote ECTI and lymph node metastases. One should be aware of the potential for ECTI in oesophageal carcinomas. In the future, adjuvant therapy may be advisable for some oesophageal carcinomas based on the phenotype of individual cancer cells, including expression of DG1.

Aged↗
PubMed1997

The difference of means of two indirect unpaired groups in receptor autoradiography.

We present an approximate method to compare the difference of the means of two groups of populations by indirect unpaired data. This indirect data structure occurs in receptor autoradiography, where the tissue distribution of receptors is visualized in the form of ligand bindings. This visualization is indirect because we can only observe and measure nonspecific bindings in one autoradiograph and total bindings in another autoradiograph. The distribution of receptors is obtained by subtracting the nonspecific bindings from the total bindings. Besides the reasoning of our method, an example is given using our experimental data.

Animals↗
PubMed1997

Synchronous and metachronous carcinomas of the esophagus and head and neck.

We retrospectively analyzed the clinicopathologic findings, treatment and outcome of 22 patients with synchronous or metachronous carcinomas of the esophagus and head and neck. The patients with metachronous cancers in whom esophageal cancer occurred first had either an early-stage esophageal carcinoma or only one positive lymph node. Similarly, five of 10 patients with metachronous cancers in whom head and neck cancer was the first tumor had early-stage esophageal carcinomas. The esophageal lesion was mucosal carcinoma in four patients which was found by endoscopy with the iodine dye method. In the patients with synchronous cancers either one or both carcinomas were advanced, and the prognosis of these patients was poor compared with those of patients with metachronous carcinomas. Accordingly, endoscopic surveillance for early detection of metachronous lesions are encouraged.

Adult↗
PubMed1997

cDNA cloning of nuclear localization signal binding protein NBP60, a rat homologue of lamin B receptor, and identification of binding sites of human lamin B receptor for nuclear localization signals and chromatin.

We previously purified and characterized a nuclear localization signal (NLS) binding protein, NBP60, in rat liver nuclear envelopes. In this study, we cloned and sequenced the cDNA of rat NBP60, and predicted an amino acid sequence comprising 620 amino acids. The sequence revealed that NBP60 is a rat homologue of lamin B receptor (LBR), and is 79 and 63% identical in amino acids to human and chicken LBR, respectively. Using three fusion proteins containing different parts of the amino-terminal domain of human LBR, it was shown that the stretch comprising amino acids 1 to 89, which contains a Ser-Arg rich region (RS region), binds to nucleoplasmin and that the binding was inhibited by a common NLS-peptide. These results suggested that the amino-terminal domain of LBR contains an NLS-binding site. Furthermore, it was shown that the stretch comprising amino acids 1 to 53, which does not contain the RS region or the predicted DNA-binding site, binds to Xenopus laevis sperm chromatin.

Amino Acid Sequence↗
PubMed1997

Gene expression of malignant rhabdoid tumor cell lines by reverse transcriptase-polymerase chain reaction.

Malignant rhabdoid tumors (MRT) are characterized by unique neoplastic cells demonstrating phenotypic diversity. By using the reverse transcriptase-polymerase chain reaction, we have detected expression of various genes before and after differentiation induction with four different agents in four established MRT cell lines (TM87-16, STM91-01, TTC642, and TTC549). The agents used in this study were all-trans retinoic acid (RA), 12-O-tetradecanoylphorbol-13-acetate (TPA), interleukin-3, or interferon-gamma. Before and after induction, c-myc, IGF-II, IGF-I receptor, and IGF-II receptor were constitutively expressed by all four cell lines. The neurofilament medium-size (NF-M) was constitutively expressed by the TM87-16 and TTC642, and the S100 protein alpha subunit was expressed by TM87-16, TTC642, and TTC549. Chromogranin A was expressed by TM87-16 only after treatment with either TPA or RA. MyoD, N-myc, tyrosine hydroxylase, N-CAM, trkA, and the S100 protein beta subunit were not expressed by any cell line before or after induction with these agents. All the MRT cell lines in this study except TM87-16 were highly resistant to differentiation induction. The proliferating cells in TM87-16 and TTC642 expressed mRNA profiles characteristic of neuroectoderm.

Cell Differentiation↗
PubMed1997

Decreased cortical glucose metabolism correlates with hippocampal atrophy in Alzheimer's disease as shown by MRI and PET.

OBJECTIVE: To investigate the relation between atrophy of the hippocampus and parahippocampal gyrus (the % hippocampal area) and cerebral metabolic rate for glucose (CMRGlc) in Alzheimer's disease. METHODS: 13 patients with probable Alzheimer's disease by NINCDS-ADRDA criteria (six men; seven women, mean age 71 years, mini mental state 13.8 (SD 4.6)) and age matched controls were studied. T1 weighted MRI (0.5T) images were used for evaluation of the hippocampal area. With a digitiser system, a percentage of the hippocampal area to the brain (the % hippocampal area) was calculated. Eight patients received another T1 weighted MRI (1.5T) for further evaluation of the minimum thickness of the hippocampus. Regional CMRGlc (rCMRGlc) was measured using PET and the FDG technique. RESULTS: The hippocampal area in patients with Alzheimer's disease was significantly lower than that of controls (P < 0.01). All the cortical rCMRGlc values in patients with Alzheimer's disease were lower than those of controls (P < 0.01). A significant correlation (P < 0.05) was found between the % hippocampal area and rCMRGlc in the temporal lobe, temporoparieto-occipital (TPO) region, and frontal lobe in Alzheimer's disease. There was a significant correlation between minimal hippocampal thickness and ipsilateral TPO metabolism on both sides. CONCLUSION: The ipsilateral correlation between hippocampal atrophy and decreased TPO metabolism in Alzheimer's disease suggests a functional relation and the asymmetries show that Alzheimer's disease is an asymmetric disease in its early stages.

Aged↗
PubMed1997

Effects of endothelin 1 on phosphate transport in brush border membrane vesicles.

Endothelin is the most potent vasoconstrictive agent released from endothelial and many other types of cells. It has been reported that endothelin has physiological effects on the rat kidney, especially on the renal proximal tubules. We investigated the role of endothelin 1 in the renal brush border membrane. The V(max) of P(i) uptake by brush border membrane vesicles (BBMV) in the endothelin-1-treated group was significantly greater than that in the control group. There were no significant changes in apparent K(m) values between the two groups. To define the direct effect of endothelin 1 on P(i) transport of BBMV, BBMV from normal rats were incubated with endothelin 1 in vitro. The P(i) uptake by BBMV incubated with endothelin 1 did not differ from that by BBMV incubated with a salt solution as a control. These results suggested the probability of the presence of endothelin 1 receptor in the proximal tubules. Administration of the endothelin 1 might increase the P(i) reabsorption by BBMV according to changes in the capacity of the transporter.

Animals↗
PubMed1997

Skipping of exon 14 and possible instability of both the mRNA and the resultant truncated protein underlie a common cholesteryl ester transfer protein deficiency in Japan.

Among the Japanese population, a G-to-A mutation at the beginning of intron 14 of the human cholesteryl ester transfer protein (CETP) gene is a frequent cause of CETP deficiency characterized by markedly increased HDL cholesterol. The resulting abnormalities responsible for null CETP deficiency were studied in detail. The CETP mRNA transcripts amplified by polymerase chain reaction from the monocyte-derived macrophages of two homozygous patients were both found to be normal except for the whole deletion of exon 14. The deletion causes a shift of reading frame and introduces a premature termination codon downstream. Examination of the macrophage RNA from heterozygotes suggested the increased instability of the abnormal mRNA in the cytoplasm, because the amount of the aberrant transcript was nearly one third that of a normal transcript in the cytoplasm, while they were equal in the nucleus. Although this indicated the synthesis of a mutant CETP that lacks about 15% at its carboxy terminus, immunoblot analysis demonstrated that the abnormal CETP was virtually absent in both the media and cell lysates of transfected COS-1 cells, which massively expressed the mutant CETP mRNA. These results elucidate the primary abnormality due to the common CETP splicing mutation to be the exon skipping of mRNA, which decreases the level of mRNA and produces a truncated protein that should be rapidly degraded intracellularly.

Alternative Splicing↗
PubMed1997

Induction of ST-segment elevation by regional myocardial stretch in normal canine hearts in vivo.

The purpose of this study was to evaluate ST-segment elevation induced by regional myocardial stretch without myocardial ischemia in canine hearts. A strain gauge arch (TH-601T) was sutured to the left ventricular epicardium, parallel to the short axis, to shorten the end-diastolic length of the myocardium beneath the arch (stretch zone; SZ) and to produce regional myocardial stretch in each of 6 dogs. An increase in preload caused by altering the height of a saline-filled reservoir affected prolongation or shortening of the myocardium both in the SZ and outside the arch (normal zone; NZ) to increase myocardial stretch. An epicardial electrocardiogram was recorded in both the SZ and the NZ. After suture of the strain gauge arch, the ST segment was elevated in the SZ. An increase in preload augmented stretch during systole in the SZ, resulting in additional ST-segment elevation. These results suggest that regional myocardial stretch itself plays an important role in ST-segment elevation.

Animals↗
PubMed1997

Isolation and characterization of chitinase from a flake-chitin degrading marine bacterium, Aeromonas hydrophila H-2330.

A flake-chitin degrading marine bacterium was isolated and identified as Aeromonas hydrophila. This strain secreted five chitinases and an beta-N-acetylglucosaminidase. The main chitinase (Chi-A) was purified and characterized. The optimum pH of Chi-A was 5-8, and the activity was inhibited by Hg2+ and Fe3+. Chi-A was different from chitinases of other Aeromonas species with respect to molecular weight (62,000) and insensitivity to monoiodoacetate. The amino-terminal amino acid sequence showed extensive similarity with chitinases from Gram-negative bacteria.

Aeromonas hydrophila↗
PubMed1997

Effect of piped water supply on human water contact patterns in a Schistosoma haematobium-endemic area in Coast Province, Kenya.

The effect of a piped water supply on human water contact in a Schistosoma haematobium-endemic area in Coast Province, Kenya was studied. After the construction of five community standpipes and one shower unit, there was a 35.1% reduction in the number of people observed using river water, a 44.1% reduction in the frequency of contact with river water, and a 25.4% reduction in the amount of contact. The frequency of river water contact per person also decreased significantly, but the amount of contact per person did not decrease. The total frequency of contact decreased significantly except for washing clothes by the river, washing utensils, and fishing. The frequency per person did not change for most of the activities and significantly increased for washing clothes. The frequency of river water contact in households with high piped water consumption showed a significant decrease compared with those with low piped water consumption. The volume of consumption of piped water was inversely proportional to the distance from the home to the community standpipe. These results indicate that in the study area, the effect of a piped water supply on river water contact behavior was heterologous while the total river water contact decreased significantly, and that the piped water had a beneficial effect on some villagers but very little effect on others.

Adolescent↗
PubMed1997

[A case report of a fenestrated Fontan operation after bivalvation of the common atrioventricular valve in right isomerism].

The patient is a boy of five years old with asplenia, dextrocardia, right aortic arch, bilateral superior vena cavae, single atrium, common atrioventricular orifice, double outlet right ventricle and pulmonary stenosis. He underwent operations of right Blalock-Taussig shunt and right superior vena cava ligation when he was eight months old and at the age of three years old, bidirectional Glenn procedure and bivalvation of the common atrioventricular valve (CAVV) as he, then, suffered from severe regurgitation of the CAVV. The regurgitation improved from grade 3 to 1 and his recovery allowed the fenestrated Fontan operation at the age of four years and nine months. Bivalvation is an effective means for the mitigation of regurgitation of CAVV and paves the way for application of Fontan-type operation.

Child, Preschool↗
PubMed1997

Oxygen delivery as a factor in the development of fatal postoperative complications after oesophagectomy.

BACKGROUND: This study was designed to assess the impact of oxygen transport variables on outcome in 115 patients undergoing elective surgery for oesophageal carcinoma. METHODS: Haemodynamic parameters were determined using a Swan-Ganz catheter in all patients on the day before operation, 6 h after operation, and daily for the first 4 days after operation. RESULTS: Oxygen delivery and consumption at 6 h were significantly higher in survivors than in non-survivors. However, oxygen delivery and consumption in both groups did not differ significantly after postoperative day 1. Of 17 patients with oxygen delivery levels lower than 445 ml min-1 m-2 at 6 h, eight died in hospital. Oxygen delivery in patients who developed either an anastomotic leak or severe pneumonia was significantly lower 6 h after surgery. Lower levels of oxygen delivery preceded postoperative complications. CONCLUSION: Oxygen delivery 6 h after oesophagectomy correlates with postoperative complications and may be a determinant of hospital mortality.

Aged↗