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Biomedical subjects

A Yamada

Publications and source records attributed to A Yamada.

At least 217 records · Page 12Linked to original sources
PubMed1998

Hypererythropoietinemia and hyperreninemia in a continuous ambulatory peritoneal dialysis patient with chronic severe hypotension.

We experienced a patient on continuous ambulatory peritoneal dialysis (CAPD) who showed hypererythropoietinemia (Epo concentration: 86.7 mU/ml, normal range: 8-36 mU/ml), erythrocytosis, high renin concentration (26.5 pg/ml) and chronic hypotension. In this patient the erythrocytosis progressed along with exacerbation of the chronic severe hypotensive state. This patient had systemic circulatory insufficiency as suggested by the fact that he had a fibrous myocardium and an increased anion gap. We hypothesized that circulatory insufficiency due to chronic severe hypotension may lead to the stimulation of the Epo production, due to a decreased oxygen supply to peripheral tissues and/or to the stimulation of the renin angiotensin system even in patients with end-stage renal failure.

Aged↗
PubMed1998

[A case report of small-sized peripheral lung cancer diagnosed by thoracoscopic biopsy].

A case who had surgical treatment for small-sized peripheral lung cancer diagnosed by thoracoscopic biopsy was reported. A 66-year-old female was admitted to our hospital because of evaluation of an abnormal shadow on chest X-ray. Chest CT showed that the tumor about 7 mm in diameter was situated in right S1b and suspected to be malignant. Transbronchial lung biopsy and brushing showed no malignancy. The tumor was finally diagnosed to be well-differentiated adenocarcinoma by thoracoscopic lung biopsy. Following this procedure, right upper lobectomy and lymph node dissection (R2a) were performed through postero-lateral thoracotomy at one stage. Pathological diagnosis showed that the tumor was well-differentiated papillary adenocarcinoma and pathological TNM classification was T1N0M0. The postoperative course was uneventful and the patient is now doing well with no relapse at 1 year 2 months after the operation.

Adenocarcinoma, Papillary↗
PubMed1998

[Relationship of utilization rate of health examination under the Elderly Act to medical expenditure and days of medical care for the elderly].

The aim of this study was to investigate the relationship of utilization rate of health examination to medical expenditure and days of medical care per insured person under the Elderly Act. The factors related with the utilization rate of health examination were also analyzed by multiple regression analysis. The material used in this analysis was the 1993 national health insurance data for all of the 3,252 municipalities of Japan. The main results were as follows: 1. The average medical expenditure and days of medical care among the municipalities declined in the increasing order of the three categories of utilization rate of health examination; municipalities with utilization rate of less than 30% being the highest, and those with 50% or more being the lowest. 2. The average medical expenditure and days of medical care among the municipalities with community health centers were smaller than those without. 3. Multiple regression analysis showed that utilization rate had a positive relationship to percentage of elderly, presence of community health center, public financial power index, and number of public health nurses per resident. It had a negative relationship to the population and the number of clinical beds per resident. The number of public health nurses per resident was the most significant factor related with the utilization rate (standardized partial regression coefficient = 0.32). These results suggest that increasing the utilization rate of health examination and the number of community health centers could serve to lower medical expenditure and days of medical care through the promotion of the health services provided by municipalities.

Community Health Services↗
PubMed1997

Bi-directional movement of actin filaments along long bipolar tracks of oriented rabbit skeletal muscle myosin molecules.

In actomyosin in vitro motility assays, orientation of myosin molecules affects their interaction with actin. We obtained long tracks of myosin molecules with uniform orientation. Bipolar filaments about 50 microm long were made from myosin rod prepared from molluscan smooth muscles, to which rabbit skeletal-muscle myosin bound, creating long synthetic thick-filaments. Movement of F-actin toward their center was much faster (4.7 +/- 0.6 microm s(-1)) than in the opposite direction (1.9 +/- 0.2 microm s(-1)), indicating that myosin molecules were arranged in the same orientation along each half of the bipolar filament. These complex thick-filaments permit measurement of actin movement over 20 microm of oriented skeletal myosin tracks facilitating mechanistic studies of actomyosin motility.

Actins↗
PubMed1997

Beta 2-integrin-mediated signal up-regulates counterreceptor ICAM-1 expression on human monocytic cell line THP-1 through tyrosine phosphorylation.

Intracellular cross-talk between LFA-1 and its counter receptor, intercellular adhesion molecule-1 (ICAM-1), on human monocytic cell line THP-1 was analyzed. Stimulation with mAb YH384 specific for LFA-1 alpha (CD11a) up-regulated ICAM-1 expression on THP-1 cells. Cell surface expression of ICAM-1 on THP-1 cells was dose-dependently up-regulated and reached the maximal level 24 hr after stimulation with mAb YH384. Up-regulation of ICAM-1 by mAb YH384 was further confirmed by Northern blotting analysis at the mRNA level, and the maximal message of ICAM-1 was observed 4 hr after stimulation. mAb YH384-induced upregulation of cell surface expression was ICAM-1-specific, and the expression of the other nine molecules tested was not augmented. Up-regulation of ICAM-1 was also observed following stimulation with other mAb specific for CD11a (S6F1), CD11b (JML-H11), and CD18 (IB4); all of these mAb recognized members of the beta 2-integrin family, but not with isotype-matched control mAb. The mAb 4B4 (specific for beta 1-integrin) similarly, but more weakly, augmented ICAM-1 expression. The effect of mAb YH384 on expression of ICAM-1 was dose-dependently suppressed by treatment with herbimycin A or genistein, both inhibitors of tyrosine kinase. These results suggest that beta 2-integrin-mediated up-regulation of ICAM-1 is mediated via a tyrosine phosphorylation pathway.

Animals↗
PubMed1997

A new sigma factor homolog in a cyanobacterium: cloning, sequencing, and light-responsive transcripts of rpoD2 from Microcystis aeruginosa K-81.

We isolated an rpoD2 gene encoding the potential sigma factor of RNA polymerase from the cyanobacterium Microcystis aeruginosa K-81, which can perform photosynthesis. The deduced amino acid sequence of RpoD2 (sigmaA2) exhibits extensive homology to other eubacterial RpoD proteins. This gene possessed multiple 5'-end transcripts, expressed specifically under light (P(L)), dark (P(D)), or constitutively light/dark (P(C)) conditions during exponential cell growth.

Amino Acid Sequence↗
PubMed1997

Increased tissue factor pathway inhibitor in patients with acute myocardial infarction.

We examined hemostatic abnormalities in 23 patients with acute myocardial infarction (AMI), 10 with pulmonary embolism (PE), and 10 with deep vein thrombosis (DVT). At the onset of AMI, plasma levels of tissue-type plasminogen activator (t-PA), PA inhibitor-I (PAI-I), fibrin-D-dimer, thrombin-antithrombin complex (TAT), and plasmin-plasmin inhibitor complex (PPIC) were significantly increased. Both the plasma total TFPI and free-TFPI levels in the AMI patients were significantly higher than those in the healthy volunteers, PE patients, and DVT patients. There was no significant difference in total TFPI or free-TFPI among patients with PE, those with DVT, and healthy volunteers. One hour after percutaneous transluminal coronary angioplasty (PTCA) in the AMI group, the total TFPI level was further increased, and it was significantly reduced 24 hr after PTCA, to a level similar to that in healthy volunteers. Free-TFPI showed a pattern similar to that of total TFPI. The ratio of free-TFPI/total TFPI was highest 1 hr after PTCA. Increased TFPI in AMI patients might be released from ischemic tissues.

Adult↗
PubMed1997

Association of Sjögren's syndrome with hereditary angioneurotic edema: report of a case.

A case of hereditary angioneurotic edema (HANE) associated with Sjögren's syndrome is presented. One of the members of a pedigree of HANE due to deficiency of C1 inhibitor (C1INH) had a positive titer for anti-SS-A and anti-SS-B antibodies in the serum, complaining of symptom of dry eyes and dry mouth. A lip biopsy revealed lymphocytic infiltration of minor salivary glands. The patient had renal tubular acidosis (RTA). Thus the patient was diagnosed as suffering from Sjögren's syndrome with RTA.

Angioedema↗
PubMed1997

Extracellular reduction of selenite by a novel marine photosynthetic bacterium.

A novel purple nonsulfur bacterium strain NKPB030619, which has resistance to over 5 mM selenite, was isolated from a marine environment. An initial concentration of 1.1 mM selenite, added to the medium, was decreased to under 0.05 mM within 5 days. The color of the cell suspension turned red within 2 days. The red coloration gradually decreased and black precipitates appeared during 2 weeks of cultivation. Under these conditions, two main types of deposit were formed extracellularly. These deposits were thought to contain red amorphous selenium and black vitreous selenium. The selenite reduction to elemental selenium in this bacterium was induced by the introduction of light and L-malic acid under anaerobic conditions. These results suggest that selenite reduction is coupled with photosynthesis and L-malic acid can serve as the indirect electron donor for its reduction. Phylogenetic analysis based on the 16S rDNA sequence showed that NKPB0360619 belongs to the alpha subdivision of Proteobacteria and is classified into the Rhodobacter species. The highest similarity of 86.2% was observed with R. sphaeroides.

Bacteria↗
PubMed1997

Control of actin moving trajectory by patterned poly(methylmethacrylate) tracks.

Poly(methylmethacrylate) (PMMA), a photoresist polymer, was found to be useful for immobilizing heavy meromyosin (HMM) molecules while retaining their abilities to support the movement of actin filaments. PMMA substrate was spin-coated on a coverslip, and various shapes of PMMA tracks, such as straight lines, concentric circles, and alphabetical letters, were fabricated by UV photolithography. An observation by a Tapping mode atomic force microscope (AFM) shows that the typical circular tracks were 1-2 microns wide and about 200 nm high. In in vitro motility assay, a solution of HMM molecules was applied to immobilize the molecules on the tracks by adsorption, and movement of actin filaments labeled with tetramethylrhodamine-phalloidin were observed in the presence of ATP by using an epifluorescence microscope and an image-intensified CCD camera. Actin filaments were seen to move precisely only on the PMMA tracks, and their traces drew the exact shapes of the tracks. The mean velocity of actin movement on the PMMA was 4.5 mm/s at 25 degrees C, and it was comparable to that on a conventionally used nitrocellulose film.

Actins↗
PubMed1997

Effect of hot water extract of Chlorella vulgaris on cytokine expression patterns in mice with murine acquired immunodeficiency syndrome after infection with Listeria monocytogenes.

We have previously reported that oral administration of hot water extract of Chlorella vulgaris (CVE) enhances resistance to Listeria monocytogenes through augmentation of Listeria-specific cell-mediated immunity in normal mice and mice with murine acquired immunodeficiency syndrome (MAIDS) caused by murine leukemia virus (MuLV) LP-BM5. To elucidate the mechanisms whereby CVE augments the cell-mediated immunity, we examined the expression patterns of mRNA for cytokines in normal and MAIDS mice given CVE orally after L. monocytogenes infection. The expression levels of IL-1 alpha, IL-12, GM-CSF, MIP and TNF alpha genes were significantly augmented in the peritoneal adherent cells by oral administration of CVE for 2 weeks before Listeria infection. The expression levels of gamma IFN and IL-12 mRNA were significantly higher in the spleen after Listeria infection in CVE-treated mice than in normal mice, while the expression of IL-10 mRNA in the spleen was decreased by CVE administration. In MAIDS mice, oral administration of CVE also augmented the expression of gamma IFN and IL-12 mRNA in the spleen after Listeria infection, while it rather reduced the expression of IL-10 mRNA. These results suggest that CVE may preferentially augment THI responses against Listeria via activation of macrophages to produce IL-12 and enhance host defence against Listeria infection both in normal and MAIDS mice.

Animals↗
PubMed1997

Preventive and therapeutic effects in rats of hepatocyte growth factor infusion on liver fibrosis/cirrhosis.

Liver fibrosis/cirrhosis is characterized by hyper-accumulation of fibrous tissue components and is commonly observed in later or terminal states of chronic hepatic diseases. In ongoing work, we found that the administration of human recombinant hepatocyte growth factor (hrHGF) suppressed the onset of liver fibrosis/cirrhosis in several distinct models and accelerated the recovery from liver fibrosis/cirrhosis in rats. Repeated administration of porcine serum for 10 weeks to rats induced liver fibrosis without any accompanying hepatocellular injuries; in addition, the intravenous (i.v.) administration of hepatocyte growth factor (HGF) to these rats suppressed increases in fibrous components and hydroxyproline contents in the liver, thus preventing the onset of liver fibrosis. Repeated administration of dimethylnitrosamine (DMN) for four weeks induced liver cirrhosis, as characterized by the hyper-accumulation of fibrous components, infiltration of mononuclear leukocytes, and hepatic dysfunction. When HGF was injected daily for four weeks along with DMN-treatment, the onset of DMN-induced hepatic fibrosis/cirrhosis was suppressed; the numbers of infiltrating mononuclear cells, fibrous tissue components, and hydroxyproline content in the liver were decreased. When HGF was injected for two weeks following four weeks of DMN-treatment, HGF accelerated the recovery from liver cirrhosis and prevented death due to hepatic dysfunction. Likewise, HGF-injection suppressed the onset of liver fibrosis, when liver fibrosis had been induced by long-term treatment with carbon tetrachloride (CCl4). Thus, the administration of HGF holds great promise for treating subjects with liver fibrosis/cirrhosis as a result of chronic hepatic injury.

Alanine Transaminase↗
PubMed1997

Oral administration of a unicellular green algae, Chlorella vulgaris, prevents stress-induced ulcer.

Oral administration of dry powder of Chlorella vulgaris (CVP) showed clear prophylactic effects in water-immersion restraint stress-induced and in cysteamine-induced peptic ulcer models, but not in Shay's rat model. Drugs that enhance the protective factors of ulcer formation are effective in the first two models. CVP may prevent ulcer formation mainly through the "immune-brain-gut" axis and protection of gastric mucosa by its own characteristics.

Administration, Oral↗
PubMed1997

Sleeve recording of upper esophageal sphincter resting pressures during cricopharyngeal myotomy.

OBJECTIVE: The manometric effects of a 6-cm cricopharyngeal myotomy are recorded while the operation is being performed from cervical esophagus to the cricopharyngeus and then to the hypopharynx. SUMMARY BACKGROUND DATA: Cricopharyngeal myotomy is used in the treatment of oropharyngeal dysphagia of different causes. The operation decreases the resting pressure in the upper esophageal sphincter (UES). The components responsible for this decrease have not been clarified. METHODS: Fourteen patients with oropharyngeal dysphagia underwent a sleeve recording of the UES resting pressures under general anesthesia before and after sequential myotomy of the pharyngoesophageal junction. Patients were assessed in the awake state before and after the whole myotomy. RESULTS: Upper esophageal pressures remain unchanged after division of 2 cm of the cervical esophageal muscle. Section of 2 cm of the cricopharyngeal area results in a significant decrease of the sphincter resting pressure (p < 0.01). The division of 2 cm of hypopharyngeal muscle results in a further significant reduction of the resting pressure (p < 0.005). CONCLUSIONS: Extension of the cricopharyngeal myotomy over hypopharyngeal musculature produces a more significant decrease of UES resting pressure.

Aged↗
PubMed1997

Follicular dendritic cell tumor with histiocytic characteristics and fibroblastic antigen.

A report is presented of a follicular dendritic cell (FDC) tumor arising in the lymph nodes and inguen of a 55-year-old Japanese female, who had suffered from schizophrenia for 25 years. The left submandibular lymph nodes had completely lost their normal architecture, except for the capsule, due to tumor cell infiltration. Occasional nodular structures resembling epithelioid granulomas, attributable, at least in part, to follicular involvement of tumor cells, were observed. These nodules were composed of epithelioid- or fibroblast-like tumor cells forming interwoven fascicles, to which small lymphocytes were attached. Tumor cells were also scattered in the internodular areas. For more atypical tumor cells, arranged in a sheet-like structure, were present in the inguinal specimen, the tumor cells of which expressed Ki-M4p, CD21, CD35 and other antigens known to be expressed on FDC. Furthermore, they also expressed the monocyte/macrophage antigens, alpha 1-antitrypsin, alpha 1-antichymotrypsin, lysozyme, CD14, CD33, CD68 and Mac387 and fibroblastic antigen. Ultrastructural studies demonstrated lysosomal granules as well as a few desmosomes, indicating the tumor cells possessed fibrohistiocytic and FDC characteristics.

Biomarkers↗
PubMed1997

Contribution of cell proliferative activity to malignancy potential in testicular seminoma.

Testicular anaplastic seminoma, which has a high mitotic activity, is regarded as more malignant than typical seminoma, although its prognosis is still unclear. To determine whether seminoma with relatively greater malignancy potential can be identified based on the cell proliferative activity, the mitotic rate (MR; mitotic count per high-power field), mitotic index (MI; mitotic count per 1000 cells), Ki-67 labeling index (Ki-67 LI; the percentage of positive cells) and proliferating cell nuclear antigen LI (PCNA LI; the percentage of positive cells) were histologically examined in 44 patients. The MI, Ki-67 LI and PCNA LI in patients with metastatic disease were significantly higher than those in patients without metastatic disease, and the MI in patients with fatal disease was significantly higher than those in patients cured of the disease. However, these distributions of the MI, Ki-67 LI and PCNA LI values overlapped for both pairs of groups. There were no significant differences in the MR. These results suggest that the cell proliferative activity makes a small contribution to the malignancy potential in testicular seminoma, with the activity being not necessarily indicative of metastasis and prognosis.

Adolescent↗