Biomedical subjects

N Uchida

Publications and source records attributed to N Uchida.

At least 127 records · Page 7Linked to original sources

PubMed1996

PCR analysis of Lewis-negative gene mutations and the distribution of Lewis alleles in a Japanese population.

Three mutations in the Lewis-negative gene, T59G, G508A and T1067A, have been detected by means of a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in 149 unrelated Japanese individuals. We found three common Lewis alleles-Le (without the T59G, G508A, and T1067A mutations), le1 (with the T59G and G508A mutations), and le2 (with the T59G and T1067A mutations) in a Japanese population. In addition, we also found one rare Lewis-negative allele, le3 (only with the T1067A mutation). The allele frequencies of Le, le1, le2, and le3 were 0.607, 0.275, 0.114, and 0.003, respectively. Our results were in accordance with those expected by the Hardy-Weinberg equilibrium. Some statistical parameters of forensic interest were also calculated.

Alleles↗

PubMed1996

[A quantitative study of regional cerebral blood flow in childhood using 123I-IMP-SPECT: with emphasis on age-related changes].

Single photon emission computed tomography (SPECT), using N-isopropyl-p-[123I] iodoamphetamine (123I-IMP) was used for quantitative analysis of regional cerebral blood flow (rCBF) on 26 individuals between 0 and 19 years of age. The rCBF showed age-related changes; it was low in early infancy, increased in late infancy through early childhood, and decreased and remained constant after puberty. The rCBF through cerebral cortex varied more greatly than through thalamus and cerebellum, and seemed to depend more closely on age. In the case of 4 months of age rCBF was very low at the frontal region and was very high at the occipital region. In more older cases, rCBF in the cerebral cortex was higher than in the thalamus. In childhood, rCBF was very inconsistent and showed a great inter-individual variance.

Adolescent↗

PubMed1996

[Mid-term results in coronary revascularization using the right gastroepiploic artery graft].

We studied the mid-term results in 191 patients (including emergent operation in 27 patients) who have performed coronary artery bypass grafting (CABG) using the right gastroepiploic artery (REGA) for 74 months (mean follow up period was 37 months). We evaluated the postoperative results in terms of 1. mortality and survival rate, 2. graft angiography, 3. cardiac event free rate and 4. abdominal complications. We had operative death in 6 patients (3.1%) including 3 patients of emergent operations. Late deaths were found in 11 patients (5.9%): 2 patients were cardiac death and 9 were non-cardiac. The actual survival rates were 94.2% at one year, 90.0% at three years and 85.9% at five years. Early patency rate of the RGEA was 98.9% (n = 178). However flow competition between the RGEA and native coronary artery was seen in 42 patients (24.0%). Mid-term patency rate was 96.4% (n = 28). According to mid-term graft angiography, 1 patient improved and 5 patients got worse in comparison with early control. Cardiac event free rates were 98.2% at 1 year, 94.8% at 3 years and 92.7% at 5 years. Abdominal complications were observed in 5 patients (1 patient of bleeding from the RGEA, 1 of gastric perforation, 2 of bleeding from gastric ulcer and 1 of pyloric stenosis) at early period and in 7 patients (2 patients of incisional hernia and 5 of gastric cancer) at long-term period. Early and mid-term results of CABG using the RGEA were quite good. However, the RGEA had a tendency of flow competition against native coronary artery and a problem of gastric cancer after the operation.

Adult↗

PubMed1995

Enrichment of human hematopoietic stem cell activity in the CD34+Thy-1+Lin- subpopulation from mobilized peripheral blood.

The number of CD34+ cells in the peripheral blood of cancer patients is known to be increased following the administration of high dose chemotherapy and hematopoietic growth factors. These so-called peripheral blood stem cell grafts are now frequently used for autologous transplantation of patients with malignancies. In this report, we address the question of whether true long-term repopulating pluripotent hematopoietic stem cells (PHSC) are mobilized into peripheral blood following chemotherapy plus granulocyte/macrophage colony-stimulating factor (GM-CSF) or granulocyte colony-stimulating factor (G-CSF) mobilization. We have examined the presence of stem cells in mobilized peripheral blood (MPB) by using an antibody to the human Thy-1 molecule to stain the CD34+Lineage- (Lin-) population. The kinetics of mobilization of CD34+Thy-1+ Lin- cells into peripheral blood were studied, and the percentage of cells with this phenotype was found to vary widely depending on the day of leukapheresis. A CD34+Thy-1+Lin- cell population, potentially containing PHSCs, was isolated by fluorescence activated cell sorting (FACS) and analyzed for activity. The multilineage differentiative capacity of this candidate stem cell-containing population in MPB was determined using an in vitro long-term culture system, in which cobblestone area formation was used as a means of detecting PHSCs. We also measured repopulating capacity by using two in vivo models in which severe combined immunodeficiency (SCID)-hu mice were implanted with human fetal bone or thymus grafts. Using these assays, we show that the highest frequency of cobblestone area-forming cells (CAFC) after 7 weeks of culture was observed in a subpopulation of CD34+Lin- cells, which expressed low levels of Thy-1. This cell population was capable of producing both B and myeloid cells, and maintaining CD34+Lin- cells in these long term cultures. Moreover, the CD34+Thy-1+Lin- cell subset possessed a higher ability to engraft and to demonstrate multilineage differentiative potential at 8 weeks in the SCID-hu bone assay. However, in the SCID-hu thymus model, both Thy-1+ and Thy-1- subpopulations were capable of donor T-cell engraftment at 6 weeks, suggesting the presence of cells capable of initiating T lymphopoiesis in both populations.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMed1995

Cadherin-11 expressed in association with mesenchymal morphogenesis in the head, somite, and limb bud of early mouse embryos.

Cadherin-11 (cad-11) is a novel member of the cadherin family of cell adhesion molecules, having recently been identified by means of the polymerase chain reaction. To study the function and expression of this molecule, we cloned mouse, cad-11 cDNA. Transfection of L cells with cDNA led them to acquire a typical cadherin-dependent cell-cell adhesiveness, and the L cells expressing cad-11 did not coaggregate with L cells expressing E-, P-, N-, or R-cadherin when they were mixed, indicating that this novel cadherin has a homophilic binding specificity, as found for other cadherins. To determine the developmental expression pattern of this molecule, we performed in situ hybridization analysis on early mouse embryos. Cad-11 first appeared in mesodermal layers only in the head and tail regions at the mid-to-late primitive streak stages. In the head, this appearance was followed by strong expression in mesenchymal tissues including branchial arches. In the trunk, the paraxial mesoderm initially did not express cad-11. However, as the somites formed, they expressed cad-11, and this expression was strictly correlated with their initial condensation and segregation from the presomitic mesoderm. The cad-11 expression in the somites was eventually restricted to sclerotome cells. As the limb buds developed, cad-11 appeared in the distal portion of the limb mesenchyme, and, at later stages, its expression was most evident at the peripheral mesenchyme. Cad-11 was thus expressed by restricted populations of mesenchymal cells in early embryos, although it was also expressed in parts of the neural tube, such as the optic vesicle and dorsal midline, and in part of the otic vesicle. As a step to investigate the role of cad-11 in mesenchymal cell adhesion, we dissociated the limb bud mesenchyme into single cells, pelleted them, and cultured them as aggregates. In these cultures, cad-11-positive cells clearly sorted out of the negative cell population, suggesting that cad-11 might be involved in selective association of mesenchymal cells. For comparison, we studied the expression of N-cadherin and found that the expressions of these two cadherins were differential, and complementary in some tissues. These results suggest that cad-11 is involved in specific associations of subsets of mesenchymal cells and also of some neural cells during early embryogenesis.

Amino Acid Sequence↗

PubMed1995

Papillary dilation vs sphincterotomy in endoscopic removal of bile duct stones. A randomized trial with manometric function.

To circumvent the long-term effects of papillary ablation for extracting common bile duct stones (< 12 mm in diameter) in endoscopic sphincterotomy (EST), endoscopic papillary dilation (EPD) was attempted in 20 patients. To evaluate papillary function before and after the procedures, manometry of the sphincter of Oddi was carried out in 13 with EPD and 10 of 20 patients with EST. Extraction of all stones was successful (100%) in both groups at an equal rate. Repeated numbers of procedures were common in both groups. However, the mean duration of the procedure was high in EPD compared to EST (63 min vs 42 min, P < NS). Adjunctive therapies like mechanical lithotripsy (ML), nasobiliary drainage, and choledochoscopy were included in EPD, while EST required a basket catheter and ML. There was no significant difference on manometry before and after the procedures (P = NS), although papillary function was found to have decreased after the EPD. In contrast, all patients in the EST group lost papillary function after the procedure. Thirty-day morbidity and mortality rate were absent in both groups. Immediate and 2.5-year follow up complications were uncommon in both groups. As a simple method, EPD may be an effective and safe alternative to EST in the management of patients with bile duct stones who require maintenance of papillary function.

Aged↗

PubMed1995

A unified model for cell-killing by heat: interpretation of continuous, step-down, step-up and split heating.

We have already proposed a model for the lethal effects of heat on cells. In the model, a three-step process for cellular inactivation was hypothesized: 1) heating produces sublethal damage; 2) the damage is repaired in a certain time period; 3) the cell is inactivated when it undergoes cumulative sublethal damage to the extent that it cannot be repaired. Using the previous model, we investigated the modifications of the survival curve in 1) continuous heating, 2) step-down heating, 3) step-up heating, and 4) recovery from the thermal injury by split heating. These four phenomena were explained well with the mathematical model.

Animals↗

PubMed1995

Surgical experience of coronary artery-right ventricular fistula in a heart transplant patient.

Routine follow-up catheterization 4 years after heart transplantation in a 55-year-old revealed a fistula from the main left anterior descending artery (LAD) to the right ventricle. The left anterior descending artery was dilated and tortuous because of this fistula. As he had effort dyspnea and fatigue 3 months after this catheterization, we decided to operate on the fistula, and direct closure of this through the LAD and coronary artery bypass grafting from the proximal to distal LAD were performed. Surgery and the postoperative course were uneventful. We discuss the surgical indication and technique for coronary artery fistula acquired as a result of endomyocardial biopsy after heart transplantation.

Biopsy↗

PubMed1995

Development of a clinically applicable high-speed flow cytometer for the isolation of transplantable human hematopoietic stem cells.

A high-speed cell sorter capable of a throughput speed 4-5-fold greater than commercially available systems was developed and evaluated as a processing tool for isolating purified hematopoietic stem cell grafts. The clinical high-speed sorter (CHSS) serves as a single-pass, multiparameter processing tool that provides the means to isolate a highly purified population of cells from starting cell populations with extremely low frequencies. The sorter incorporates environmental barriers to create a sterile environment for cell processing. Monoclonal antibodies and reagents produced under good manufacturing practices (GMP) are used to isolate hematopoietic stem cells by means of the CHSS. Using this technology, the CD34+Thy-1+Lin- hematopoietic stem cell population has been isolated from normal adult bone marrow and mobilized peripheral blood. The sorted cells have been shown to be sterile and viable and to retain hematopoietic function.

Cell Separation↗

PubMed1995

Quality of peptic ulcer healing induced by lansoprazole and roxatidine.

This study reports preliminary results of a controlled, multicenter trial on the quality of ulcer healing induced by lansoprazole (LPZ) or roxatidine (R) in gastric ulcer (GU) or duodenal ulcer (DU) patients. Group A received LPZ 30 mg q.d. and group B received R 75 mg b.i.d. All drugs were given for 8 weeks in GU and for 6 weeks in DU. Endoscopy and gastric biopsy were performed to detect Helicobacter pylori before and on completion of treatment. The healing rates of groups A and B were 100 and 69.2%, respectively, in GU and 100 and 70.0%, respectively, in DU. This difference (p < 0.01) was significant between the two groups in GU. There was no significant difference between the two groups in the S2 stage shift rate in GU and DU. The H. pylori clearance rates of groups A and B were 33.3 and 20.0%, respectively, in GU and 62.5 and 33.3%, respectively, in DU. The differences in treatment response (healing rates and S2 shift rates) between the LPZ group and the R group may be related to the differences in suppression of acid secretion and in bactericidal effects on H. pylori.

2-Pyridinylmethylsulfinylbenzimidazoles↗

PubMed1995

Frequent p53 accumulation in the chronically sun-exposed epidermis and clonal expansion of p53 mutant cells in the epidermis adjacent to basal cell carcinoma.

p53 expression was studied immunohistochemically to identify a precursor lesion of basal cell carcinoma (BCC) in the epidermis adjacent to BCC. With two different anti-p53 antibodies of CM1 and DO7, p53 expression was frequently detected in the epidermis adjacent to BCCs arising on the face and in the normal epidermis with usual sun exposure. In the epidermis adjacent to BCC, stained cells were occasionally clustered in a small area, but no cluster was found in the normal epidermis with usual sun exposure. The expression was less frequent in the normal epidermis with rare sun exposure. Ten cases of normal skin with usual sun exposure, showing CM1 staining in the epidermis, were screened for p53 gene mutations with polymerase chain reaction-single-strand conformation polymorphism analysis using DNAs obtained from the epidermis. No mutation was detected in exons 2 to 10 of the p53 gene in these 10 cases. The epidermis flanking three BCCs that was stained with CM1, on the other hand, carried a missense mutation of C to G transversion at a dipyrimidine site of codon 249. This alteration replaced arginine with threonine. The mutation of codon 249 was not detected in the three BCCs. Our results first suggest that ultraviolet light irradiating the skin in a daily life induces p53 accumulation in the epidermis and secondly that the frequent clonal expansion of p53 mutant cells occurs in the epidermis adjacent to BCCs. This clonal expansion of mutant p53 may provide a molecular basis for high risk of developing subsequent new skin cancers in patients with BCC.

Adolescent↗

PubMed1995

The biology of hematopoietic stem cells.

Hematopoietic stem cells (HSC) are the only cells in the blood-forming tissues that can give rise to all blood cell types and that can self-renew to produce more HSC. In mouse and human, HSC represent up to 0.05% of cells in the bone marrow. HSC are almost entirely responsible for the radioprotective and short- and long-term reconstituting effects observed after bone marrow transplantation. The subsets of HSC that give rise to short-term vs long-term multilineage reconstitution can be separated by phenotype, demonstrating that the fates of HSC are intrinsically determined. Here we review the ontogeny and biology of HSC, their expression of fate-determining genes, and the clinical importance of HSC for transplantation and gene therapy.

Adult↗

PubMed1995

Changes of hepatic microsomal oxidative drug metabolizing enzymes in chronic renal failure (CRF) rats by partial nephrectomy.

Male SD rats, 7-weeks-old, were used to investigate the changes in the hepatic drug metabolizing system of chronic renal failure (CRF) model rats. Partial nephrectomy (5/6) was performed in a two-stage surgical procedure. After nephrectomy, the rats were housed under regular conditions at least 21 days. After confirming the CRF states, trimethadione (TMO, 100 mg/kg, i.p.) was administered for evaluation of the hepatic drug metabolizing capacity; the ratio of dimethadione (DMO: the only metabolite of TMO) to TMO (DMO/TMO) in the serum and the dialysate from the blood microdialysis method were ascertained. The hepatic drug metabolizing enzyme contents and activities were also determined. In the CRF rats, the DMO/TMO ratios decreased significantly; total cytochrome P450 (CYP) contents, aminopyrine N-demethylase activity and delta-aminolevulinic acid synthetase activity also decreased significantly in the CRF rats. The extent of the alterations of these enzyme contents and activities correlated well with the severity of the CRF states evaluated by the serum blood urea nitrogen and creatinine concentrations. With Western blot analysis, the levels of CYP2C6, CYP2C11 and CYP3A2 decreased considerably in the CRF rats. These results suggest that CRF states induce not only a reduction of renal function but also an alteration of hepatic metabolism.

Animals↗

PubMed1995

[Endoscopic lithotomy using sublingual nitroglycerin].

After medical sphincter dilation using sud-lingual nitroglycerin, endoscopic removal of common bile duct stones in 15 patients was carried out. Complete stone removal was obtained in 14 of 15 patients. Only 0.3 mg to 0.6 mg nitroglycerin was needed to give an enough dilation of the orifice for cannulating the basket catheter into the bile duct. Mechanical lithotriptor was smoothly cannulated in one patient because of possible impaction. Blood pressure was dropped transiently in one patient by nitroglycerin, however, the general condition of the patient was stable. This procedure is safe, easy and effective in preserving sphincter function. Acute cholecystitis, a common complication of persistent gallbladder stone after endoscopic sphincterotomy, may be avoided by employing this method. More clinical studies, on long term and in a large scale of patients, are necessary to reduce complications that usually occur after sphincterotomy.

Female↗

PubMed1995

Cytokine-mobilized peripheral blood CD34+Thy-1+Lin- human hematopoietic stem cells as target cells for transplantation-based gene therapy.

Gene-therapy of blood-borne disorders may be best achieved using hematopoietic stem cells (HSC) which have extensive self renewal potential as well as multilineage repopulating potential as a cellular target. The human HSC, which is CD34+Thy-1+Lin- has been isolated from fetal, adult bone marrow and cytokine-mobilized peripheral blood (MPB) (1-3). Results presented in this study show that the degree of mobilization of HSC into peripheral blood of cancer patients is highly variable and that the combined use of high dose chemotherapy and GM-CSF as a mobilization strategy is superior to the use of G-CSF with regard to the mobilization of true HSC. A multistep cell isolation procedure has been developed which utilizes high speed flow-cytometric cell sorting and allows the isolation of sufficient numbers of HSC from MPB to permit their use as an hematopoietic graft for clinical transplantation. Hematopoietic stem cells isolated from MPB are capable of self-renewal and differentiation into multiple hematopoietic lineages as shown by their behavior in both in vitro and in vivo assays. Mobilized PB mononuclear cells isolated from cancer patients are frequently contaminated with tumor cells. Using this cell isolation procedure, HSC preparations from patients with multiple myeloma have been created with greatly reduced tumor cell burdens. These CD34+Thy-1+Lin- cells are capable of being stably transduced at high efficiency (32-75%) by co-culture on a cell line producing recombinant retroviruses containing the neomycin-resistant gene. These HSC cell populations are likely ideal targets for hematopoietic cell-based gene therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1995

[Separate perfusion of upper and lower body under mild hypothermia during operation on the thoracoabdominal aorta].

During last 7 years, we performed 24 operations on the thoracoabdominal aorta. There were 9 true and 15 dissecting aneurysms. There were two cases of ruptured aneurysm and thoracoabdominal replacement was performed as a last stage operation for total aortic replacement in 4 cases. Three cases with aortic dissection died within 30 days after surgery. Femoro-femoral bypass was used in 4 cases (1 case died of brain damage, paraplegia and MOF), left heart bypass in 5 cases and separate perfusion of upper and lower body (SPULB) under deep hypothermia in 7 cases (2 cases died of LOS and cerebrovascular accident occurred at 2 weeks after operation) and SPULB with mild hypothermia in 8 cases for circulatory support. There was one case of renal dysfunction and transient mild liver dysfunction occurred in 7 cases. There was no evidence on relationship between surgical outcome and methods of circulatory supports, but we recently prefer SPULB under mild hypothermia for thoracoabdominal surgery since intraoperative massive bleeding and cardiac arrest can be easily treated and major organs can be protected by introducing hypothermia in this perfusion technique.

Adult↗

PubMed1995

[Y-grafting using the inferior epigastric artery for coronary revascularization].

On view of the remarkable good results obtained with arterial grafts for coronary revascularization, the authors continue to conduct the total arterial bypass grafting. However, the following disadvantages are encountered; 1) arterial graft crossing over the aorta and 2) left internal thoracic artery (LITA) is on some occasions impossible to anastomose with the left anterior descending (LAD) coronary artery. To eliminate these problems, "IEA Y-grafting" which the IEA is anastomosed with the LITA in an end-to-side fashion was conducted. From January to December 1994, 24 patients underwent coronary revascularization by this method. All 24 IEA grafts were anastomosed to the circumflex coronary artery (22), right coronary artery (3) or diagonal branch. (1). LITA graft were used on 24 patients (29 anastomosis) with the right gastro-epiploic artery (RGEA) at 16 (17) and RITA at 2. Immediate postoperative angiographic evaluation of the IEA grafts indicated 17 anastomoses to be patent (17/19, 89.5%). Two patients died due to coronary spasm. Although hypoperfusion poses a serious problem in this method, IEA may be considered to serve as a 3rd alternative for an arterial conduit.

Aged↗

PubMed1995

[Dislodgement of the ringed-graft--a case report].

A 70-year-old man underwent replacement of the distal aortic arch which contained a huge aneurysm using a ringed graft. He died suddenly of hemoptysis 54 months following the operation. An autopsy revealed dislodgement of the spool on the posterior aspect of the aorta. Histologic examination of the dislodged portion of the ring showed complete disruption of the intima and elastic fibers of the media. There were minimal histologic changes in the anterior portion of the anastomotic site. It is postulated that the long, kinked graft might have caused the late ring dislodgement.

Aged↗