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Biomedical subjects

S Maeda

Publications and source records attributed to S Maeda.

At least 667 records · Page 37Linked to original sources
PubMed1990

Structure and function of G protein coupled receptors.

The G protein coupled receptors (GPC-Rs) comprise a large superfamily of genes encoding numerous receptors which all show common structural features, e.g., seven putative membrane spanning domains. Their biological functions are extremely diverse, ranging from vision and olfaction to neuronal and endocrine signaling. The GPC-Rs couple via multiple G proteins to a growing number of recognized second messenger pathway, e.g., cAMP and phosphatidyl inositol turnover. This review summarizes our current knowledge of the molecular mechanisms by which the GPC-Rs activate second messenger systems, and it addresses their regulation and structure.

Amino Acid Sequence↗
PubMed1990

Photodynamic therapy for early gastric cancer using a pulsed gold vapor laser.

Endoscopic photodynamic therapy (PDT) using a pulsed gold vapor laser (wavelength 628 nm, LaserSonics Inc.) was performed on eight cases of early gastric cancer. Three patients refused to have surgery, and the others were in a high-risk group due to old age or complications with other diseases. Hematoporphyrin derivative (HpD I, 2.5-3 mg/kg, Photofrin Inc.) was injected intravenously, and 48-72 hours later, the entire cancer lesion and 5 mm width mucosa encircling it were irradiated with a gold vapor laser through a single quartz fiber. The irradiation was delivered at 300-330 mW for 5-20 minutes, which gave about 90 J/cm 2 dosage. In seven of eight cases, local cure was achieved. Recurrence was noted only in one patient. In one of eight patients, operation was carried out 1 month after PDT. Pathological examination of the resected stomach revealed that the effect of PDT extended into the tunica muscularis propria. Side effects of HpD, such as skin rash, were noted in two patients, but no serious complications of PDT were encountered. This suggests that PDT with a pulsed gold vapor laser is clinically useful in the treatment of early gastric cancer.

Adult↗
PubMed1990

Fibronectin-related substance located in the chief cells of human and rat gastric mucosa.

A novel substance located in the chief cells of human and rat gastric mucosa, which was detected immunologically by either polyclonal or monoclonal antihuman fibronectin (FN) antibodies, is reported. All three polyclonal antihuman FN antibodies used in this study reacted immunohistologically exclusively with the chief cells. Monoclonal antibody against C-terminal peptide or cell binding peptide reacted clearly with the human chief cells, but monoclonal antibodies against FN N-terminal and midmolecule failed to react with the cells. Western blot analysis of the rat gastric mucosal extract with polyclonal antihuman FN antibody showed that this substance has a molecular weight of about 70,000 Da. Therefore, this substance appears to be a fragment containing the C-terminal peptide of whole molecule FN and thus in the present study is named FN-related substance (FNRS). In a further study with ethanol-induced ulcer model of the rat, the physiological significance of FNRS was examined. The FNRS decreased remarkably, in a dose-dependent manner, in the fundic mucosa of the rats that ingested ethanol. The FNRS appeared to be associated with development of mucosal damage and repair, subsequently playing, in part, an important role in the gastric mucosal protection mechanism.

Animals↗
PubMed1990

Characteristically distinct isolates of the nuclear polyhedrosis virus from Spodoptera litura.

More than 100 isolates were plaque-purified to examine the genetic variations in four wild stocks of Spodoptera litura nuclear polyhedrosis virus (NPV) collected in Japan. These isolates were characterized by their in vitro host range in three established insect cell lines, growth characteristics, polyhedral protein, DNA restriction endonuclease pattern and DNA hybridization. The isolates were separated into four distinct groups: (I) isolates corresponding to Autographa californica NPV, (II and IV) two different groups of isolates of S. littoralis NPV which had been previously characterized and (III) isolates with no correspondence to any reported virus group. Of the S. litura NPV wild stocks, two were mixtures of more than two different groups of NPVs. We have discussed the advantage of having a mixture of different NPV groups in the same wild virus stocks.

Animals↗
PubMed1990

Molecular cloning and physical mapping of the genome of Bombyx mori nuclear polyhedrosis virus.

A restriction fragment library which covered the entire genome of Bombyx mori nuclear polyhedrosis virus (BmNPV) was constructed using plasmid vectors. By analysis of cloned and viral DNA by double digestion with endonucleases and by hybridization techniques, a complete physical map of BmNPV was constructed for BamHI, EcoRI, HindIII, KpnI, PstI and SmaI. Five regions of repeated sequences containing EcoRI sites were also found and mapped.

Animals↗
PubMed1990

Perioperative blood transfusion and gastric cancer: adverse effects or unfavourable conditions of pretreatment?

The use of perioperative blood transfusion (PBT), the immunological status pre-operatively and at discharge from hospital, and the clinical course were examined retrospectively in 124 patients who underwent 'curative' resection for gastric cancer at Shinkokura Hospital, Japan from 1979 to 1988. The general condition of patients with PBT was worse than that of those without PBT and the pre-operative immunological status of patients with PBT was less favourable than that of those without PBT. At the time of discharge from hospital the immunological condition remained worse for patients who had been given PBT. The clinical course of patients with PBT was significantly worse. A dose-response relationship was evident but the types of blood products did not influence the outcome. Cox regression analysis adjusting for potentially confounding prognostic factors revealed that the clinical course was not altered by perioperative blood transfusion itself. These observations do not support the idea of adverse effects of perioperative blood transfusion on outcome of patients undergoing 'curative' resection for gastric cancer.

Actuarial Analysis↗
PubMed1990

Evidence for multiple OmpR-binding sites in the upstream activation sequence of the ompC promoter in Escherichia coli: a single OmpR-binding site is capable of activating the promoter.

We present experimental evidence for the existence of multiple activator-binding sites in the upstream sequence of the ompC promoter, the expression of which is activated by the positive regulator OmpR in response to the osmolarity of the medium. We also found that a single OmpR-binding site can activate the ompC promoter, providing that the binding site is close and placed stereospecifically with respect to the canonical-35 and -10 regions.

Bacterial Outer Membrane Proteins↗
PubMed1990

Analysis of lymphocyte subsets of bone marrow in patients with rheumatoid arthritis by two colour immunofluorescence and flow cytometry.

Lymphocyte subsets defined by monoclonal antibodies were investigated in bone marrow and peripheral blood of 17 patients with rheumatoid arthritis (RA); 13 patients with osteoarthritis or aseptic necrosis served as controls. Patients with RA were found to have a raised OKT 4/8 ratio both in bone marrow and peripheral blood in comparison with the controls. Furthermore, bone marrow of RA showed a lower percentage of OKT 8+ T cells than that of controls. The percentage of HLA-DR+ T cells was higher in bone marrow than in peripheral blood of RA, though a slightly lower percentage was detected in bone marrow than in peripheral blood of controls. Thus T cell subsets in bone marrow of RA differ significantly from those of controls. Patients with RA had a higher OKT 4/8 ratio and a higher percentage of HLA-DR+ T cells in bone marrow than controls, suggesting that T cell subsets in bone marrow of RA are in an immunologically activated state and that T cell subsets are affected by rheumatoid inflammation in bone marrow of RA.

Adult↗
PubMed1990

Fundamental study on the mechanism of DNA degradation in tissues fixed in formaldehyde.

The mechanism of DNA degradation and its clinical applications were examined. When purified lambda phage and extracted liver DNA were fixed in phosphate buffered formaldehyde, the DNA did not degrade, but there was incomplete digestion with endonuclease. Rat liver tissues were fixed under various conditions and DNA extracted. Immediate fixation with buffered formaldehyde at low temperature, or the addition of EDTA to buffered formaldehyde blocked the DNA degradation. Analysis of pulsed field gel electrophoresis also showed that DNA was degraded before extraction. These results suggest that tissue nuclease has an important role in DNA degradation in tissue. Furthermore, formaldehyde fixation at low temperature, which may take time and which decreases slightly the staining capacity, is useful for the extraction of intact DNA. For clinical application, the detection of provirus was examined. Genomic DNA was extracted from a necropsy sample of adult T cell leukaemia fixed in formaldehyde; human T cell leukaemia virus type-I (HTLV-I) provirus was successfully detected by Southern blotting.

Animals↗
PubMed1990

Type A behavior pattern as a risk factor for coronary heart diseases.

This is a study of type A behavior pattern in patients with coronary heart diseases (CHD). Type A behavior pattern (coronary-prone behavior pattern) has been recognized as a risk factor for CHD in western countries. Three hundred patients with new onset of CHD (243 cases of acute myocardial infarction and 57 cases of unstable angina pectoris) between 1981 and 1987 were analysed from the standpoint of behavior pattern. Type A behavior pattern assessed by Jenkins Activity Survey (JAS) was found in 64.6% of subjects and in 43.0% of healthy controls (p less than 0.05). Concerning occupational position, the majority of patients in the administrative class showed type A behavior pattern. Type A behavior pattern was not related with other traditional risk factors (hypertension, hypercholesterolemia and smoking) and was related with angiographically documented severity of coronary atherosclerosis. Emotional stress load by mirror drawing test (MDT) evoked more elevation of blood pressure and plasma catecholamine level in type A patients than in type B patients. A follow-up of post CHD patients, whose occupational position belonged to the administrative class and/or whose work load did not decrease after CHD, modification of type A behavior pattern seemed to be difficult. In conclusion, we consider that type A behavior pattern exists also in Japanese CHD patients, and plays an important role in the development of CHD.

Coronary Angiography↗
PubMed1990

[A clinical study of hypertrophic obstructive cardiomyopathy in the elderly].

Seven elderly patients with hypertrophic obstructive cardiomyopathy (HOCM), who had the three following characteristics on echocardiograms 1) extremely thickened septum, 2) systolic anterior motion of the mitral valve, 3) mid systolic semi-closure of the aortic valve, were clinically evaluated. Ages ranged from 73 to 86 years old (average 78.9% yr.) and all were women. None had not a family history of hypertrophic cardiomyopathy but they had mild hypertension. Six patients showed a significant high voltage on the ST-segment and T-wave abnormalities ("strain" pattern). The left ventricular posterior wall as well as the septum was thickened in 5 and the remaining 2 showed asymmetrical septal hypertrophy (ASH) on echocardiograms. The left ventricular cavity was narrowed due to left ventricular hypertrophy and the shape of the left ventricular cavity was ovoid in all patients. The aorto-septal angles in these 7 patients were 80 degrees to 120 degrees. In addition, proximal septal bulge in all and anterior displacement of the mitral posterior leaflet due to the mitral ring calcification (MRC) in some patients contributed to the narrowing of the left ventricular outflow tract, and the mitral valve was pulled up toward the septum because of the good left ventricular systolic function (ejection fraction: 70 to 94% by echocardiography) and blood was ejected at a high velocity through a narrowed outflow tract (Venturi effect). Pressure gradients in the left ventricular outflow tract was 38 to 146 mmHg in 5 examined by cardiac catheterization. Biopsy specimens were obtained from 2 patients, showing hypertrophic myocytes (diameter: 20 to 30 micron) in 2 and mild disarray in 1.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

[Clinical and pathological study on 47 cases of renal pelvic and ureteral tumors].

47 cases including 24 renal pelvic tumors, 20 ureteral tumors and 3 renal pelvic and ureteral tumors treated in our hospital from January, 1980 to December, 1987, were studied clinico-histopathologically. The patients ranged in age from 38 to 81 years (average 65 years) the sex ratio was 3:1 with male predominance over female. Tumor occurred on the right side in 19 cases, on the left side in 27 cases and bilaterally in 1 case. The most frequent sign was hematuria which was observed in 40 cases (85%). The interval from the onset of initial symptoms to the first visit was within one month in 9 cases (19.1%). The major findings of excretory urograms were filling defect in 21 cases (47.1%) and non-visualizing kidney in 15 cases (33.8%). Positive urinary cytology was obtained in 21 cases (44.7%). Operative therapy as performed in 45 cases, namely, nephroureterectomy and partial cystectomy in 30 cases (66.7%) and nephroureterectomy in 9 cases (20%). Histopathologically, all cases but two cases of squamous cell carcinoma and to cases of mixed type carcinoma are transitional cell carcinoma. Subsequent bladder tumors were found in 8 cases (17.7%). The overall survival rate at 1, 3 and 5 years were 80.2%, 41.1% and 41.1%, respectively by Kaplan-Meier method. In this series, the interval from the onset of initial symptoms, the grade and stage of tumor and metastasis of lymph nodes were to be considered in developing prognosis.

Adult↗
PubMed1990

[A study on cisplatin adsorbed to activated carbon particles as a new drug delivery system and its anti-cancer effect against human bladder cancer cell lines].

Activated carbon characteristically shows an extremely high transmigration to the lymph node, as well as a sustained release of the adsorbed drugs. Therefore, several attempts to use activated carbon as a carrier in cancer chemotherapy have been done. In the present study, we first introduced a new drug-dosage form of cisplatin (CDDP) adsorbed to activated carbon particles (CDDP-CH), and examined its characteristics and anti-cancer effect against human bladder cancer cell lines. CDDP solution of varied concentrations (Randa) was mixed with activated carbon particles (Norit A) and examined for adsorption and discharge by atomic absorption spectrophotometry and high performance liquid chromatography. Total CDDP adsorption increased in proportion to the amount of activated carbon. CDDP-CH was successfully prepared at an efficient concentration for cancer chemotherapy and CDDP-CH slowly discharged CDDP, indicating it as a useful means for the anti-cancer drug. Using cultured human bladder cancer cell lines (KU-1, HTB9), the anti-cancer effect was compared between CDDP and CDDP-CH by MTT-assay and double layer soft agar colony assay. CDDP-CH revealed an inhibitory effect against human bladder cancer cell lines. In view of the fact that activated carbon readily migrates to the lymph node, clinical application of this drug dosage form may be useful in cases of malignant tumor metastasis to the lymph node.

Cell Line↗
PubMed1990

[Endoscopic and fluoroscopic pyeloureterotomy for ureteropelvic junction obstruction and ureteral stricture].

Endoscopic or fluoroscopic pyeloureterotomy was performed in a total of 32 patients (34 ureters) with ureteropelvic junction obstruction (UPJO) or ureteral stricture from March 1985. Cold incision was performed, using a flexible knife over a guidewire, endoscopically on 23 ureters and fluoroscopically on 11 ureters. The mean operation time was 98.9 +/- 48.3 minutes. Twenty-five (74%) of the 34 ureters showed relief of subjective symptoms, normalized urinalysis and radiographical improvement of hydronephrosis with a mean follow-up period of 11.7 +/- 10.0 months (range: 3-43). The clinical results by etiology were as follows: primary UPJO, 13/16 (81%); secondary UPJO, 4/4 (100%); ureteral stricture, 6/7 (85%); obliteration of ureteral implantation, 2/7 (29%). No major complication was noted with this endourological technique. This endourological technique might be clinically useful for the treatment of UPJO and ureteral strictures.

Adolescent↗
PubMed1990

Association of HLA-DR antigens with disease severity in Japanese patients with rheumatoid arthritis.

Twenty eight Japanese patients with rheumatoid arthritis (RA) were tested for HLA-DR antigens to investigate genetic influence on disease severity and prognosis. The severity of RA was assessed by clinical, laboratory and radiological indexes. HLA-A, B, C and DR typing was performed using sera described at the 3rd Asia and Oceania Histocompatibility Workshop. HLA-DR4.1 was significantly higher in RA patients (50%) compared with controls (27.6%). HLA-DRw53 was also higher in RA patients, although DRw52 was lower in those than controls. When the relationship between HLA-DR antigens and the clinical severity of RA was investigated, the patients with HLA-DR4 had a severer disease than DR4 negative patients. In contrast, HLA-DR2 positive patients had significantly better functional scores than DR 2 negative patients. We next investigated specific genes likely to be directly involved in the pathogenesis of RA. Although the new restriction fragment length polymorphisms (RFLPs) were found in DR2 positive patients, no association was found between the RFLPs and the clinical severity of RA. Furthermore there were no differences in the frequencies of the RFLPs in HLA-DR4 positive patients compared with DR4 negative patients. It may be concluded that the severity of RA appears to be influenced by several different genes or molecules rather than by a single gene or gene product linked to HLA-DR2 or DR4.

Adult↗
PubMed1990

Solitary brain metastasis from renal cell carcinoma 14 years after nephrectomy: a case report.

We report a case of solitary brain metastasis from renal cell carcinoma (RCC) 14 years after nephrectomy. A 46-year-old female had sudden onset of headaches, aphasia, gait disturbance and right hemiparesis. A brain CT revealed a cystic tumor in the left parietal area, which was surgically removed completely. Microscopic appearances of the brain tumor were similar to those of the primary RCC. Positive immunoreaction for epithelial membrane antigen (EMA) and keratin confirmed the diagnosis of metastatic RCC. This is the second case of solitary brain metastasis from RCC occurring more than 10 years after nephrectomy.

Brain Neoplasms↗