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Biomedical subjects

S Ito

Publications and source records attributed to S Ito.

At least 253 records · Page 14Linked to original sources
PubMed2001

Renin containing cells are present predominantly in scarred areas but not in dysplastic regions in multicystic dysplastic kidney.

PURPOSE: Hypertension is an important complication of multicystic dysplastic kidney and it has been suggested that it is induced by renin. Little information is available on renin production in this disease. To assess renin production we examined the distribution of renin containing cells in multicystic dysplastic kidneys using immunohistochemical methods. MATERIALS AND METHODS: Immunohistochemical examination of renin was performed in 29 multicystic dysplastic kidneys from 14 boys and 15 girls 1 month to 10 years old using rabbit anti-human renin antibodies. In all cases normal renal function was confirmed by the serum creatinine level and no proteinuria on urinalysis. Two patients had the complication of hypertension before removal of the multicystic dysplastic kidney but plasma renin activity was normal. RESULTS: Immunostaining of renin was observed in 26 of 29 multicystic dysplastic kidneys (90%). Histologically multicystic dysplastic kidney involved scarred and dysplastic areas. Renin positive cells were observed predominantly in the scarred areas, mainly in the juxtaglomerular apparatus of mature glomeruli, interlobular arteries and some mature tubules. Immunopositive renin was sparsely noted in the juxtaglomerular apparatus or Bowman's capsules of occasional immature glomeruli in dysplastic areas. CONCLUSIONS: Our observations suggest that multicystic dysplastic kidney may have the ability to produce renin. Renin producing cells in the juxtaglomerular apparatus of mature glomeruli and interlobular arteries in the scarred areas may be the predominant source of renin production in this organ.

Female↗
PubMed2001

Recurrent giant longitudinal duodenal ulcer with massive hemorrhage in a Helicobacter pylori-negative patient.

A 67-year-old man, in whom a linear ulcer running from the duodenal bulb to the descending part had been noted 3 years previously, was admitted to our hospital because of abdominal pain and melena. Duodenoscopy revealed a bleeding giant longitudinal ulcer, which was more extensive than before. Tests for Helicobacter pylori (Hp) were negative. The ulcer was cured by endoscopic hemostasis and repeated blood transfusions. Attention must be paid to Hp-negative post-bulbar duodenal ulcers because of the frequent complications including hemorrhage.

Aged↗
PubMed2001

[Strategy for post coronary artery bypass grafting in patients with bypass graft stenosis: comparison of percutaneous transluminal coronary angioplasty for the native coronary artery, internal mammary artery and saphenous vein graft].

OBJECTIVES: The strategy for post coronary artery bypass grafting (CABG) was investigated in patients with graft stenosis. METHODS: The study included 123 post-CABG patients with graft stenosis. The patients were divided into three groups according to target vessels; saphenous vein graft (SVG; n = 72), internal mammary artery (IMA; n = 21) and native coronary artery (n = 30). Furthermore, SVG lesions were divided into proximal anastomosis (n = 23), body (n = 40) and distal anastomosis (n = 9). The procedural success rate and late patency rate were compared between the three groups. Furthermore, the relationships between pre percutaneous transluminal coronary angioplasty (PTCA) percentage diameter stenosis, procedural success rate and late patency rate were evaluated. RESULTS: Procedural success rate was similar in the three groups, but late patency rate was higher in the IMA group. Procedural success rate and late patency rate were significantly lower in proximal anastomoses compared to other sites of SVG stenoses, IMA group and native coronary artery group (p < 0.05). Totally occluded native coronary artery lesions had a high procedural success rate compared with occluded IMA and SVG lesions, but the late patency rate was not higher. Procedural success rate showed no significant difference for 75-99% stenotic lesions, but the late patency rate was significantly higher in the IMA group (p < 0.05). Patients in the stenting group had a greater late patency rate compared with the balloon angioplasty group. There was no significant difference in late patency rate between the IMA group and SVG group. CONCLUSIONS: Late patency rate of the IMA is higher than that of the native coronary artery. SVG with proximal anastomosis and severe stenosis shows a significantly lower late patency rate than the native coronary artery. Therefore, PTCA should be considered for the native coronary artery in the absence of chronic total occlusion.

Aged↗
PubMed2001

[Chylothorax as the initial manifestation of malignant pleural mesothelioma--a case report].

A case of chylothorax associated with diffuse malignant pleural mesothelioma in a 53-year-old woman was reported. Chest radiography in a mass examination revealed right pleural effusion. A thoracentesis yielded fluid with characteristics consistent with chyle. In spite of our suggestion that thoracoscopy for further examination was necessary, the patient and her husband had refused the operation for months. Chest CT scanning revealed a nodule behind the xiphoid process. Lymphoscintigraphy suggested an obstruction of the right parasternal lymphatic vessel. Repeated thoracentesis did not yield a diagnosis. As bilateral pleural effusion and chylous ascites appeared, dyspnea worsened. About 2 years after the mass examination thoracoscopy was performed. On thoracoscopic exploration, a nodule was found in the anterior mediastinum and a biopsy was performed. Histological analysis revealed that the patient had the epithelial subtype of malignant pleural mesothelioma. Thoracoscopic pleural biopsy is a useful means of establishing the nature of a chylous effusion. In adult patients with chylothorax, thoracoscopic exploration should be performed as soon as possible to rule out malignancy.

Chylothorax↗
PubMed2001

Autonomic nervous function in patients with peptic ulcer studied by spectral analysis of heart rate variability.

This study is intended to clarify the relationship between occurrence of peptic ulcer disease and dysfunction of the autonomic nervous system. We studied heart rate variability and assessed the circadian rhythm of autonomic nervous function in 20 patients with peptic ulcer (PU group) and 20 age-matched healthy controls (N group) using 24-hour Holter monitoring. Moreover, the relationship between gastric juice secretion and autonomic activity was examined under intravenous injection of insulin or butylscopolamine in adult mongrel dogs. High frequency spectral (HF) power, an indicator of parasympathetic tone, was increased markedly at night in the PU group. Low frequency spectral (LF) power, an indicator of sympathetic tone modified by vagal tone, was higher during the day than at night in the N group, whereas this normal circadian rhythm of LF power disappeared in 11 cases (55%) in the PU group. In addition, the LF power was increased significantly at night (p<0.01) in the PU group. HF power and gastric juice secretion was increased by the administration of insulin. High sympatho-vagal tone at night may result in spasm of gastric arteries and excess secretion of gastric acid in the PU group. These results suggest that the nocturnal acceleration of LF, HF, and LF/HF is related to peptic ulcer diseases.

Adult↗
PubMed2001

Evaluation of the total health promotion plan in Japan, as related to health promotion effects and the prevention of lifestyle-related diseases.

The present study was undertaken to investigate whether health-promoting activities in Japan are useful for preventing the development of lifestyle-related diseases and for promoting health. One thousand, one hundred and sixty-seven Japanese workers were given a medical health check and had their maximum oxygen uptake measured according to the total health promotion plan (THP) protocol, which the Japanese Ministry of Health, Labor and Welfare is actively planning. Correlations between the maximum oxygen uptake and performance on health check items were statistically evaluated. The maximum oxygen uptake was positively correlated with the duration of a worker's ability to stand on one leg, and on the frequency with which they performed upper body weight lifting. In addition, the maximum oxygen uptake was negatively correlated with age, body weight, thickness of subcutaneous fat in the upper arms and shoulders, body fat ratios, body mass index (BMI), maximum and minimum blood pressures, resting heart rates, and total cholesterol levels. Moreover, the maximum oxygen uptake tended to be significantly higher in both male and female subjects who exercised regularly. It is suggested that maximum oxygen uptake and regular exercising play important roles in the inhibition of risk factors for ischemic heart diseases. Therefore, we believe the THP can play an important role in the primary prevention of lifestyle-related diseases. The purpose of the THP in Japan is to promote the achievement of healthy lifestyles in individual subjects, both from mental and physical perspectives. These results suggest that such efforts may help prevent the development of lifestyle-related diseases.

Adult↗
PubMed2000

Promoter analysis and characteristics of the 5'-untranslated region of the mouse glial cell line-derived neurotrophic factor gene.

We have cloned the mouse GDNF cDNA and genomic DNA to study the molecular mechanism of gene expression. Primer extension and RT-PCR analyses indicated that the mouse gene contains 1086 bp of 5'-untranslated region (5'-UTR) [Gene 203 (1997) 149]. In this report, we identified the core promoter region of mouse GDNF and examined the role of the 5'-UTR in gene expression. Promoter deletion analyses indicated that the proximal region (-81 to +28), which includes a TATA-box, is necessary for high-level expression of GDNF. Using reporter constructs encoding luciferase or fusion gene of GDNF to enhanced green fluorescent protein that were transiently transfected to mouse astroglial cell-line TGA-3 cells and rat glioma C6 cells, we investigated effects of the 5'-UTR on promoter activity. Luciferase reporter assay indicated that a region downstream of the transcription initiation site may include a positive regulatory element, while two more distal regions appear to contain negative regulatory elements, which was correlated to the mRNA level based on RNase protection assay. Both negative regulatory elements attenuated promoter activity in a position-dependent manner. Nuclear proteins from C6 glioma cells were shown to interact with several regions (+65/+105, +233/+265, and +554/+582) including each of the regulatory elements, suggesting that regulation of GDNF expression by the 5'-UTR occurred mainly at the transcriptional level.

3T3 Cells↗
PubMed2000

Novel oxidatively stable subtilisin-like serine proteases from alkaliphilic Bacillus spp.: enzymatic properties, sequences, and evolutionary relationships.

The genes for five subtilisin-like serine proteases from alkaliphilic strains of Bacillus exhibiting resistance to oxidative inactivation were cloned and sequenced. The deduced amino acid sequences of the enzymes were highly homologous (greater than 88% identity). They were composed of 638 or 639 amino acids, including a possible approximately 200-amino acid prepro-peptide, and unique stretches of approximately 160 amino acids were found in the C-terminal regions. The molecular masses of mature enzymes (433 or 434 amino acids) were approximately 45 kDa for all. Amino acid sequence comparison and phylogenetic analysis indicated that these enzymes are far removed from other known subtilisins in the line of molecular evolution. We propose that these novel proteases be categorized as a new class of subtilisins, named oxidatively stable, alkaline protease.

Amino Acid Sequence↗
PubMed2000

Ultrathin SiO(x) Film Coating Effect on the Wettability Change of TiO(2) Surfaces in the Presence and Absence of UV Light Illumination.

Wettability of sol-gel TiO(2) film surfaces has been studied by following the H(2)O contact angle (straight theta) as functions of illumination time and subsequent dark storage time. Upon illumination of the TiO(2) surface (lambda(ex)>300 nm), the value of straight theta rapidly decreased to reach approximately zero (photoprocess). When the resultant superhydrophilic sample was stored in the dark, the straight theta value increased slowly with increasing storage time (dark process). Ultrathin SiO(x) films were formed on the surface of TiO(2) by repeating chemisorption of 1,3,5,7-tetramethylcyclotetrasiloxane and its photooxidation. With increasing thickness of the SiO(x) monolayer coating, the rate for the dark process significantly decreased, while that for the photoprocess also decreased. Both X-ray photoelectron spectroscopic studies and product analyses during the photoprocess clarified that photocatalytic oxidation of organic adsorbates in air causes the superhydrophilicity of the TiO(2) surfaces. Copyright 2000 Academic Press.

Journal Article↗
PubMed2000

Synthesis and self-assembly of functionalized hexa-peri-hexabenzocoronenes.

Monolayers of hexa-alkyl substituted derivatives of hexa-peri-hexabenzocoronene (HBC) 1b have previously been investigated by scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS). It is expected that different functional groups (electron donating or withdrawing) connected to the aromatic core will influence the packing pattern and possibly the current-voltage characteristics as well. In order to provide suitable model systems, a new synthetic approach to synthesize functionalized HBC derivatives has been developed. This was accomplished by [4 + 2]-cycloaddition of suitably bromo-substituted diphenylacetylenes and 2,3,4,5-tetraarylcyclopenta-2,4-dien-1-ones followed by an oxidative cyclodehydrogenation with iron(III) chloride/nitromethane. Using this strategy three different substitution patterns were synthesized: 2-bromo-5,8,11.14,17-pentadodecylhexa-pecri-hexabenzocoronene (2a), 2,5-dibromo-8,11,14,17-pentadodecylhexa-peri-hexabenzocoronene (2b), and 2,11-dibromo5,8,14,17-pentadodecylhexa-peri-hexa-benzocoronene (2c). These bromo-substituted HBC derivatives were subjected to palladium catalyzed coupling reactions to give donor (alkoxy, amino) as well as acceptor (ester, cyano) substituted derivatives. The self-assembly of these new HBC derivatives was studied in the bulk as well as at an interface. DSC, optical microscopy, and X-ray diffraction revealed the existence of columnar mesophases. The bulk structure in the mesophase is largely insensitive to changes of the substitution pattern; however, in situ scanning tunneling microscopy at the solid-fluid interface between an organic solution of the HBC derivative and highly oriented pyrolytic graphite reveals different packing patterns of the first adsorbed monolayer.

Journal Article↗
PubMed2000

Prognosis of isolated systolic and isolated diastolic hypertension as assessed by self-measurement of blood pressure at home: the Ohasama study.

BACKGROUND: Although the clinical significance of systolic-diastolic hypertension and isolated systolic hypertension has been established, the significance of isolated diastolic hypertension has not been fully investigated. OBJECTIVE: To clarify the prognostic significance of isolated systolic and isolated diastolic hypertension as assessed by self-measurement of blood pressure (BP) at home (home BP measurements), which has a better reproducibility and prognostic value than casual BP measurements in the general population. SUBJECTS AND METHODS: We obtained home BP measurements for 1913 subjects aged 40 years or older, then followed up their survival status (mean, 8.6 years). We classified the subjects into the following 4 groups according to their home BP levels: systolic-diastolic hypertension, isolated systolic hypertension, isolated diastolic hypertension, and normotension. The prognostic significance of each type of hypertension for the risk of cardiovascular mortality risk was investigated using a Cox proportional hazards regression model adjusted for possible confounding factors. RESULTS: The risk for isolated systolic hypertension and systolic-diastolic hypertension were significantly higher than the relative hazard for normotension, while isolated diastolic hypertension was associated with no significant increase in risk. Home pulse pressure measurement was also independently associated with an increase in the risk of cardiovascular mortality. CONCLUSIONS: Isolated diastolic hypertension, as assessed by home BP measurements, carried a low risk of cardiovascular mortality, similar to that found in subjects with normotension, suggesting that the prognosis of hypertension would be improved by treatment focused on systolic rather than on diastolic home BP measurements. To our knowledge, this study is the first to demonstrate the clinical significance of pulse pressure as assessed by home BP measurement. Arch Intern Med. 2000;160:3301-3306.

Adult↗
PubMed2000

Evidence of renal metabolism of ifosfamide to nephrotoxic metabolites.

Nephrotoxicity is a limiting factor in the use of ifosfamide in children. Despite the co-administration of uroprotective agents such as sodium 2-mercaptoethanesulfonate (mesna), ifosfamide chemotherapy is associated with nephropathy characterized by glomerular toxicity and Fanconi syndrome in many children treated with this drug. This is in distinction to cyclophosphamide, an analogue which differs solely by the position of a chloroethyl group, and which is not associated with nephrotoxicity. We hypothesized that ifosfamide is metabolized by cytochrome P450 (CYP) enzymes located in the renal tubular cell to the toxic metabolite chloroacetaldehyde; and, that the higher production of chloroacetaldehyde from ifosfamide than from cyclophosphamide explains the clinical differences in nephrotoxicity. We found that in both pig renal cortical microsomes and whole human kidney microsomes incubated with 1 mM ifosfamide for 3 hr, 2 and 3 dechloroethylifosfamide (DCEI) were produced. Our study provides evidence that porcine and human kidney microsomes are capable of biotransforming ifosfamide to DCEI metabolites that are produced in equimolar amounts with chloroacetaldehyde, indicating that chloroacetaldehyde is locally produced by renal cells as a possible mechanism for nephrotoxicity.

Animals↗
PubMed2000

Novel alternative promoters of mouse glial cell line-derived neurotrophic factor gene.

We previously isolated cDNA and genomic DNA of the mouse glial cell line-derived neurotrophic factor (GDNF) gene and found that the gene consists of three exons. Recently, it was suggested that an alternative promoter exists within intron 1 of the human GDNF gene, but this has not been confirmed. Novel cDNA clones of the mouse GDNF gene were isolated by 5'-rapid amplification of cDNA ends from postnatal day-14 striatum. A novel exon, containing 351 nucleotides, exists between exon 1 and exon 3 (referred to as exon 2 in our previous report). Luciferase reporter assay showed that a core promoter for the novel exon 2 requires its 5'-untranslated region. Primer extension analysis and reverse transcription-PCR identified another novel transcript that starts 39 bp upstream of exon 3, and the core promoter activity exists within a region containing putative Sp1 sites. Although the core promoters for the novel exons are different from those previously identified, transcripts derived from each promoter coincidentally increased with interleukin-1beta or tumor necrosis factor-alpha stimulation. Gel retardation assays suggested that the NF-kappaB binding site in intron 1 would be involved in the cytokine response of the mouse GDNF gene.

Animals↗