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Biomedical subjects

M Ueda

Publications and source records attributed to M Ueda.

At least 271 records · Page 15Linked to original sources
PubMed1999

Alveolar ridge augmentation by distraction osteogenesis using titanium implants: an experimental study.

The left mandibular premolars were extracted from five adult dogs. After twelve weeks, a box-shaped osteotomy of the alveolar bone was carried out and two 10 mm implants were placed 5 mm into the transport alveolar segment, leaving 5 mm exposed. The alveolar bone was vertically augmented 5 mm by screwing the implants. After distraction, the implants were left to integrate into the bone. Histological and radiographical evaluations showed the lifting of the transport segment and the development of new bone in the distraction area. Although integration of implants within both the transport segment and the regenerated bone was observed, two of the ten implants failed and partial bone resorption of the transport segment was noted.

Alveolar Process↗
PubMed1999

Centrosomes, microtubules and cell migration.

Directed cell movement is an immensely complex process that depends on the co-operative interaction of numerous cellular components. Work over the past three decades has suggested that microtubules play an important role in the establishment and maintenance of the direction of cell migration. This chapter summarizes recent work from our laboratory designed to determine the roles of the microtubules and centrosome position relative to the direction of cell migration in a variety of cell types, and discusses these observations in the context of work from other laboratories. The results suggest that microtubules are required for stabilization of the direction of migration in many, but not all, cell types. For the centrosome to act as a stabilizer of cell migration requires that it is repositioned behind the leading edge. However, the process of repositioning does not precede the extension of a leading edge and the establishment of a new direction of cell migration. Rather, the centrosome follows the repositioning of the leading edge in response to other stimuli and, in doing so, stabilizes cell movement.

Animals↗
PubMed1999

[Molecular alterations in Barrett's esophagus and adenocarcinoma].

Patients with Barrett's columnar-lined esophagus are at increased risk of developing esophageal adenocarcinoma, the incidence of which has increased rapidly especially in the USA. Although the number of patients with Barrett's adenocarcinoma is fewer in Japan than in the USA, all gastroenterologist should know its multistep carcinogenic process. Tumor suppressor genes (p53, p16), oncogenes (c-erbB-2, H-ras, K-ras, cyclin D1, src), and growth factor/receptor (TGF-alpha, EGFR) seem to cause the malignant transformation of Barrett's esophagus. Because detection of these molecular alterations is feasible, more accurate diagnosis of Barrett's esophageal biopsy specimens should be made by adding the molecular examination to the conventional pathologic examination.

Adenocarcinoma↗
PubMed1999

[Onset of acute eosinophilic pneumonia after resumption of smoking].

We report a case of acute eosinophilic pneumonia (AEP) apparently caused by the resumption of smoking. A 38-year-old woman was admitted to our hospital because of dry cough, high fever and chest pain. Arterial blood gas analysis revealed pronounced hypoxemia and chest X-ray film disclosed diffuse bilateral infiltrate throughout all lung fields. Eosinophils (43.7%) were significantly increased in bronchoalveolar lavage fluid (BALF). The patient was treated with pulse therapy consisting of methylprednisolone and improved quickly. AEP was diagnosed on the basis of BALF findings and the patient's clinical course. Prior to and after her illness, the only noteworthy change in the patient's environmental setting or habits was the resumption of smoking, 3 days after which the symptoms had appeared. We reasoned that the onset of AEP in this patient was strongly related to the resumption of smoking.

Adult↗
PubMed1999

[Risk factor of liver disorders caused by flutamide--statistical analysis using multivariate logistic regression analysis].

The antiandrogenic drug, flutamide (Odyne), is widely used in the treatment of carcinoma of prostate. It is well known that flutamide has adverse effects of liver disorders. To ascertain the risk of liver disorders before administering this drug, past history and lifestyle preferences were resurveyed in 123 patients who had been treated with flutamide. The results obtained were assessed in relation to the occurrence of liver disorders by multivariate logistic regression analysis. The incidence of liver disorders was 26% (33/123), with 64% of the disorders occurring within 9 months. The chi-square test for dependent variables revealed that three variables, i.e., body mass index, past history of liver disorders and elevated glutamic-pyruvic transaminase levels were significantly related to the incidence of liver disorders (p > 0.05). Multivariate analysis indicated that a history of liver disorders and elevated alanine aminotransferase (ALT) levels were related to a higher incidence of liver disorders. Elevated ALT levels were associated with a higher incidence of liver disorders and smoking was related to a lower incidence of the liver disorders.

Alanine Transaminase↗
PubMed1999

[Recent clinical trials for sepsis: analysis of the results and future perspectives].

Recent clinical trials with experimental immunotherapeutic agents for sepsis have not proven their overall benefit yet although some studies suggested significant effect of these antisepsis therapies. This review article summarizes the results of these trials, their analysis, lessons learned from past failure, and future perspectives for immunotherapies as anti-sepsis treatments.

Animals↗
PubMed1999

[Economical evaluation for drug consultation at home].

We started drug consultation at patients' homes in October, 1998. The number of drug consultations are 2.65 per month per patient and the consulting time is 2.25 hours per patient. The fee for drug consultation is 550 points twice a month. We evaluate the fee for drug consultation. Our data suggest that this fee needs to be 550 points three times a month.

Aged↗
PubMed1999

[Molecular biology in gastric cancer].

In gastric cancer, the process of carcinogenesis is thought to occur as a stepwise accumulation of genetic abnormalities. However, the mechanisms of the process of multistage carcinogenesis is still unknown for gastric cancer. Gene abnormalities seen in gastric cancer, including ras, myc, c-erbB-2, met, K-sam and cript are summarized herein. Abnormalities of cancer suppressor genes, including p53, RB and APC are also described. In our studies, the biological malignancy of patients with c-erbB-2 amplification was higher than that of patients without amplification. Moreover, the cases with amplification of c-erbB-2 were found to be highly correlated with distant organ metastasis. However, very little is currently known of the molecular abnormalities leading to gastric cancer. In order to clarify the multiple gene abnormalities in gastric cancer, we used the method of restriction landmark genomic scanning (RLGS). RLGS provides a useful method for genomic analysis of gastric cancer. In the future, new analytical methods that will permit screening of all gene abnormalities at once promise to improve our understanding of the mechanisms of gastric cancer.

Genes, erbB-2↗
PubMed1999

Usefulness of dental implants in maxillofacial reconstruction.

Fabricating maxillofacial prosthesis can be challenging. Placement of implants can have a dramatic effect on the stability and retention of the prosthesis in patients. This article provides clinical retrospective analysis of osseointegrated implants used for maxillofacial reconstruction. Patient charts and radiographs were reviewed to determine implant status, stability of prosthesis, and masticatory and speech function. Of the 104 implants placed, there were 4 implant failures. The overall survival rate for implants in this patient population was 96.1%. The stability of maxillofacial prostheses demonstrated significant improvement after anchorage to implants. Implant-borne maxillofacial prostheses are better stabilized and retained than non-implant-borne prostheses, providing an improved quality of life to patients requiring prosthesis rehabilitation of maxillofacial defects.

Adult↗
PubMed1999

Quantitative analysis and in situ localization of human telomerase RNA in chronic liver disease and hepatocellular carcinoma.

Telomerase is a specialized type of reverse transcriptase that catalyzes the synthesis and extension of telomeric DNA. High levels of telomerase activity have been detected in most hepatocellular carcinoma (HCC) tissues; very weak telomerase activity is, however, detected in approximately half of nontumorous chronic liver disease tissues. The purpose of this study was to investigate the possible source of this weak telomerase activity in these tissues using quantitative competitive reverse transcription (RT)-polymerase chain reaction (PCR) and in situ RT-PCR. Competitive RT-PCR indicated that the relative amount of human telomerase RNA (hTR) was significantly higher in chronic hepatitis or liver cirrhosis compared with the normal liver (p < 0.005), and in HCC compared with the normal liver (p < 0.001) and with chronic hepatitis or liver cirrhosis (p < 0.0001). In the normal liver tissue, hTR was detected by in situ RT-PCR in occasional sinusoidal cells and nuclei of occasional hepatocytes. In tumor-free liver or tumor-bearing liver, hTR was detected in sinusoidal cells, infiltrating lymphocytes, occasional proliferative bile ductal epithelial cells, and the nuclei of occasional hepatocytes. In HCC, hTR was detected in nuclei of all HCC cells as an intense signal and in sinusoidal cells. These results indicate that the amount of hTR increases in the nuclei of hepatocytes during hepatocarcinogenesis, and that the cells associated with the weak telomerase activity in approximately half of the nontumorous chronic liver lesions are mainly migrating lymphocytes and sinusoidal cells.

Adult↗
PubMed1998

Vascular endothelial growth factor (VEGF) expression in human coronary atherosclerotic lesions: possible pathophysiological significance of VEGF in progression of atherosclerosis.

BACKGROUND: Vascular endothelial growth factor (VEGF) is an important angiogenic factor reported to induce migration and proliferation of endothelial cells, enhance vascular permeability, and modulate thrombogenicity. VEGF expression in cultured cells (smooth muscle cells, macrophages, endothelial cells) is controlled by growth factors and cytokines. Hence, the question arises of whether VEGF could play a role in atherogenesis. METHODS AND RESULTS: Frozen sections from 38 coronary artery segments were studied. The specimens were characterized as normal with diffuse intimal thickening, early atherosclerosis with hypercellularity, and advanced atherosclerosis (atheromatous plaques, fibrous plaques, and totally occlusive lesions). VEGF expression as well as the expression of 2 VEGF receptors, flt-1 and Flk-1, were studied with immunohistochemical techniques in these samples at the different stages of human coronary atherosclerosis progression. The expression of VEGF mRNA was also studied with reverse transcription-polymerase chain reaction. Normal arterial segments showed no substantial VEGF expression. Hypercellular and atheromatous lesions showed distinct VEGF positivity of activated endothelial cells, macrophages, and partially differentiated smooth muscle cells. VEGF positivity was also detected in endothelial cells of intraplaque microvessels within advanced lesions. In totally occlusive lesions with extensive neovascularization, intense immunostaining for VEGF was observed in accumulated macrophages and endothelial cells of the microvessels. Furthermore, VEGF mRNA expression was detected in atherosclerotic coronary segments but not in normal coronary segments. The immunostainings for flt-1 and Flk-1 were detected in aggregating macrophages in atherosclerotic lesions and also in endothelial cells of the microvessels in totally occlusive lesions. CONCLUSIONS: These results demonstrate distinct expression of VEGF and its receptors (flt-1 and Flk-1) in atherosclerotic lesions in human coronary arteries. Considering the multipotent actions of VEGF documented experimentally in vivo and in vitro, our findings suggest that VEGF may have some role in the progression of human coronary atherosclerosis, as well as in recanalization processes in obstructive coronary diseases.

Adult↗
PubMed1998

Hydrophobilization of esterase by genetic combination with polyproline or polytyrosine at the carboxyl terminal.

Polyproline (Poly-Pro) that is an amphiphilic polypeptide, or polytyrosine (Poly-Tyr) that is a hydrophobic polypeptide, were connected to the carboxy terminus of Pseudomonas sp. esterase by the recombinant DNA technique. The hydrophobicity of the esterase was enhanced by the introduction of Poly-Pro or Poly-Tyr, and also by increasing chain length of the polypeptides. Poly-Tyr increased the hydrophobicity of esterase more than Poly-Pro. Poly-Tyr induced significant conformational change of fusion esterase, but Poly-Pro did not. Consequently, the introduction of Poly-Tyr led to loss of activity of the fusion enzyme to a negligible level. On the other hand, the Poly-Pro-fusion-esterase retained enzymatic activity and the hydrolytic activity (kcat/Km) of the fusion esterase carrying 40 proline residues (esterase-Pro40) relative to that of the wild-type esterase with the substrates p-nitrophenyl-propionate, -pentanoate, and -hexanoate was 1.76, 1.95, and 4.7, respectively. The results could be explained in terms of easier access of long-chain carboxylate to the fusion esterase compared to the wild-type esterase in aqueous solution.

Base Sequence↗
PubMed1998

Hydrophobilization of an esterase by genetic combination with polyproline at the carboxyl terminal

Polyproline, which is an amphiphilic polypeptide, was incorporated into the carboxyl terminal of an esterase by the recombinant DNA technique. The hydrophobicity of the esterase increased with increasing chain length of polyproline without inducing significant conformational changes. The mutant esterase catalyzed the hydrolysis of long-chain carboxylic acid ester more efficiently than the native esterase. It is considered that the alteration of substrate specificity is due to enhanced access of the mutant esterases to hydrophobic substrates. Copyright 1998 John Wiley & Sons, Inc.

Journal Article↗
PubMed1998

Analysis of deleted variant of hepatocyte growth factor by alanine scanning mutagenesis: identification of residues essential for its biological function and generation of mutants with enhanced mitogenic activity on rat hepatocytes.

To understand the structure-function relationship of hepatocyte growth factor (HGF) in more detail, we analyzed one of the other forms of HGF, deleted variant of HGF (dHGF), by alanine scanning mutagenesis. We show here that there are at least four sites important for dHGF to stimulate DNA synthesis in cultured adult rat hepatocytes, and that the residues of HGF essential for exerting its biological activity are not identical to those of dHGF. In addition, two mutants showed a decrease (approximately three-fold) in EC50 compared with wild-type dHGF in an assay of mitogenic activity on rat hepatocytes.

Alanine↗