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Biomedical subjects

Y Sakamoto

Publications and source records attributed to Y Sakamoto.

At least 325 records · Page 18Linked to original sources
PubMed1994

[Percutaneous transluminal angioplasty of the ilio-femoro-popliteal arteries: initial and long-term results].

The initial and long-term results of percutaneous transluminal angioplasty (PTA) were assessed in 254 atherosclerotic lesions of the ilio-femoro-popliteal arteries in 130 patients. There were 122 men and 8 women, aged 36-85 years (average, 68 years). Follow-up periods ranged from 1 to 131 months, with a mean of 42 months. PTA was performed in 6 patients in Fontaine's stage I, 112 patients in stage II, and 12 patients in stage III-IV. We reported initial success rates of 92%, 58%, 83% and 74% for iliac stenosis, occlusion, femoro-popliteal stenosis and occlusion, respectively. Overall, the initial success rate was 82% (203/247). The 5-year patency rates according to Kaplan-Meier analysis were 70%, 69% and 63% for iliac stenosis, occlusion and femoro-popliteal stenosis, respectively. In femoro-popliteal occlusion, the 1-year patency rate was 42%, which was significantly worse than that for stenosis (P < 0.01). The longest patency periods obtained were 131 months in the iliac artery, and 106 months in the femoro-popliteal artery. The recurrence rate within 6 months was significantly higher in patients with diabetes. The recurrence rate between 6 and 12 months was significantly higher in patients with poor run-off, and those of advanced age.

Adult↗
PubMed1994

Lipopolysaccharide primes human basophils for enhanced mediator release: requirement for plasma co-factor and CD14.

Lipopolysaccharide (LPS) is known to enhance IgE-mediated basophil degranulation. Recently, the complex of LPS and plasma LPS-binding protein(LBP) has been shown to induce secretory response via CD14 in monocytes and neutrophils. In the current study, we observed that the sensitivity to LPS of basophils was increased to 100-fold by co-incubation with plasma. LPS promptly completed its effect and amplified degranulation by stimuli bypassing IgE-receptors. Treatment with anti-CD14 completely abolished the priming effect of LPS. These results indicate that the priming effect of LPS on basophil mediator release is mediated via CD14, and that plasma co-factor, possibly identical to LBP, potentiates this reaction.

Acute-Phase Proteins↗
PubMed1994

[Transluminal atherectomy for occlusive peripheral vascular disease: preliminary results].

We studied the preliminary results of atherectomy of atherosclerotic lesions involving the lower extremities in 10 patients. Fifteen arterial stenotic lesions, five iliac, eight superficial femoral, one popliteal, and one anterior tibial, were treated. Five lesions were re-stenoses after balloon angioplasty, while the remaining lesions were previously untreated primary stenoses. For atherectomy, over-the-wire atherectomy catheters ranging in size from 7 to 10-F were used. Balloon angioplasty was also performed in cases 3, 6 and 9. Atherectomy was considered a success in all patients based on angiographic and clinical criteria. Complications occurred in three patients: intimal dissection, distal embolism and arterial spasm. In the patients with distal embolism, a surgical approach was required to remove the embolus. The internal elastic lamina or media was resected in 10 lesions on the histopathologic specimens. Although further assessment of complications and long-term results is required, these results suggest that atherectomy is useful for treating occlusive peripheral vascular disease.

Aged↗
PubMed1994

In vitro effects of CINC/gro, a member of the interleukin-8 family, on hormone secretion by rat anterior pituitary cells.

We investigated the effects of CINC/gro on hormone secretion using normal rat anterior pituitary cells. In normal anterior pituitary cells, 10-100 ng/ml of CINC/gro significantly increased the secretion of PRL within 3 h of incubation, and two-fold enhancement of PRL secretion was induced by 100 ng/ml of CINC/gro within 24-h incubation, while the response of GH and ACTH secretions to CINC/gro was weak. On the other hand, CINC/gro suppressed basal LH and FSH secretions in a concentration-dependent manner. The percent inhibition of basal secretion by CINC/gro (50 ng/ml) within 24-h incubation was 70% for LH and 43% for FSH. Twenty-four-hour incubation with 100 ng/ml of IAP completely blocked the CINC/gro-stimulated PRL and GH secretions and CINC/gro's suppression of both basal LH and FSH secretions. These data demonstrate a new biological activity for CINC/gro and provide evidence for immune system regulation of anterior pituitary hormone secretion.

Analysis of Variance↗
PubMed1994

The production of CINC/gro, a member of the interleukin-8 family, in rat anterior pituitary gland.

We investigated the possibility of detection of CINC/gro, which is a IL-8-like neutrophil chemoattractant, immunoreactivity in rat normal anterior pituitary gland by immunohistochemistry, western blot analysis and an ELISA. We first ascertained the possibility of detection of CINC/gro immunoreactivity in the anterior pituitary gland by immunocytochemistry. In the anterior lobe of the pituitary gland, a few CINC/gro-like immunoreactive cells were observed (1-3% of all cells in the anterior pituitary). The positive cells were middle or large in size and looked angular in shape. Intense immunoreactivity was observed in the cytoplasm but not in the nucleus. Analysis by immunoblotting with anti-CINC/gro antiserum gave a characteristic single CINC/gro band with a molecular weight of 6.3 kDa. CINC/gro immunoreactivity was also detected in 3-h conditioned medium of normal anterior pituitary cells by an ELISA, and that immunoreactivity increased significantly in a time-dependent manner during 24-h incubation. This immunoreactivity could be induced by TNF-alpha in a dose-dependent manner. These findings indicate that CINC/gro is produced in pituitary gland and also suggests the possibility that CINC/gro may play some role asa modulator of anterior pituitary function, especially in the cross-talk mechanism between the immune and neuroendocrine systems.

Analysis of Variance↗
PubMed1994

In vitro effects of CINC/gro, a member of the interleukin-8 family, on interleukin-6 secretion by rat posterior pituitary cells.

We investigated the effects of CINC/gro on IL-6 secretion by rat posterior pituitary cells. CINC/gro immunoreactivity was already detected in 1-h conditioned medium of normal posterior pituitary cells, and it increased significantly in a time-dependent manner during the first 24 h of culture. This immunoreactivity could be induced by TNF-alpha in a dose-dependent manner. On the other hand, CINC/gro stimulated IL-6 secretion by posterior pituitary monolayer cultures in a concentration dependent manner. Thus, CINC/gro significantly (P < 0.01) increased the secretion of IL-6 within 13 h of incubation, and this effect continued throughout 24 h of incubation. The stimulatory effect of 100 ng/ml CINC/gro on IL-6 secretion was completely blocked by 24-h incubation with 100 ng/ml IAP. These data demonstrate a new biological activity for CINC/gro in the posterior pituitary system.

Animals↗
PubMed1994

Acetylated low density lipoprotein reduces its ligand activity for the scavenger receptor after interaction with reconstituted high density lipoprotein.

Complexes of apolipoprotein A-I (apoA-I) with phospholipids are known to induce cholesterol efflux from cells. In a cholesteryl ester accumulation system in which rat peritoneal macrophages were incubated with acetylated low density lipoprotein (acetyl-LDL) and either dimyristoylphosphatidylcholine complexes (DMPC/apoA-I) or native high density lipoprotein (HDL), DMPC/apoA-I exhibited a much stronger effect than native HDL in preventing cholesteryl ester accumulation. The mechanism for this phenomenon was investigated in the present study. After 18 h incubation with DMPC/apoA-I in a cell-free system, acetyl-LDL was re-isolated from DMPC/apoA-I by Sephacryl S-300 gel filtration chromatography. Re-isolated acetyl-LDL exhibited an increase in its phospholipid content by 86% as well as a reduction in the electrophoretic mobility. Its endocytic degradation by macrophages was reduced by 60% when compared with control acetyl-LDL, suggesting a significant reduction in the ligand activity for the macrophage scavenger receptor. Transfer of apolipoproteins between acetyl-LDL and DMPC/apoA-I did not occur. These results indicate that transfer of DMPC from DMPC/apoA-I to acetyl-LDL weakens the ligand activity for the scavenger receptor due probably to a decrease in net negative charge. This study demonstrated for the first time that lipid modification (change in the lipid moiety) of acetyl-LDL can induce alteration in its apolipoprotein moiety, leading to a significant loss of its biological activity. Because discoidal HDLs are known to occur in vivo, this phenomenon may explain one of the anti-atherogenic functions of HDL in vivo.

Animals↗
PubMed1994

[Percutaneous transluminal angioplasty of the subclavian arteries].

We studied the complications and long-term results of percutaneous transluminal angioplasty (PTA) of subclavian artery stenosis in 11 patients. In all patients but one, the systolic blood pressure before PTA in the arm on the involved side was at least 30 mmHg lower than that in the opposite arm. PTA of 11 left subclavian arteries and one right subclavian artery was attempted. Five of the patients suffered from symptoms of vertebrobasilar insufficiency as well as ischemia of the upper limb, two had only cerebral symptoms, two had only ischemia of the upper limb, and another had no symptoms related subclavian arterial lesion. Standard techniques for PTA were employed, using the femoral route eight times and the axillary route four times. Angioplasty was successful in 11 lesions (92%). In the successfully treated patients, the blood pressure in the ipsilateral arm was significantly increased after PTA. No complications occurred during or after the procedure. The patients were followed for 2-74 months (mean 25.7 months). During this time, no recurrence of the stenosis was observed, although the symptoms of vertebrobasilar insufficiency did not always improve. These results suggest that PTA is useful for treating subclavian artery stenosis.

Adult↗
PubMed1994

Expression of insulin-like growth factor II by a gastric carcinoma associated with hypoglycaemia.

A gastric cancer with liver metastases was associated with low morning levels of plasma glucose (24 mg/dl), insulin (< 2.5 microU/ml) and growth hormone (0.23 ng/ml). Primary and metastatic tumour tissue stained positively with anti-insulin-like growth factor II (IGF-II) monoclonal antibody. Western immunoblot analysis revealed a high molecular weight IGF-II in the serum: 15 kDa (normal: 7.5 kDa). Postmortem reverse transcription polymerase chain reaction on mRNA from both sites revealed 471 base pairs size cDNA encoding prepro-IGF-II. These results suggest that the gastric carcinoma encoded, expressed, and secreted IGF-II, probably causing the extrapancreatic tumour hypoglycaemia.

Aged↗
PubMed1994

Specific immunotherapy reduces the antigen-dependent production of eosinophil chemotactic activity from mononuclear cells in patients with atopic asthma.

BACKGROUND: The efficacy of specific immunotherapy has been verified. There is accumulating evidence focusing on the T lymphocyte-eosinophil interaction in the pathogenesis of asthma. The aim of this study was to clarify whether immunotherapy affects the production of eosinophil chemotactic activity (ECA) from peripheral blood mononuclear cells (PBMC). METHODS: PBMC obtained from persons with bronchial asthma who were sensitive to Dermatophagoides farinae (Df) or from healthy volunteers were cultured for 96 hours in the presence or absence of Df. ECA in culture supernatants was assayed by means of the modified Boyden's chamber method. RESULTS: There was no significant difference in the baseline levels of ECA between asthmatic persons treated with immunotherapy and those without immunotherapy. The addition of Df (10 to 10(4) ng/ml) enhanced the ECA production in a dose-dependent fashion in asthmatic persons without immunotherapy, and there was a statistically significant correlation between the concentrations of Df and the levels of ECA (rk = 0.34; p < 0.05). In contrast, Df-dependent ECA production was suppressed in asthmatic persons with immunotherapy, and the suppressive effect was observed from 4 weeks after rush immunotherapy. CONCLUSIONS: These results indicate that immunotherapy induces the suppression of antigen-dependent production of ECA from PBMC. This may contribute to the attenuation of eosinophil infiltration into the airways in asthma patients.

Adolescent↗
PubMed1994

Platelet aggregation inhibiting activity of human placental chorioepithelial brush border membrane vesicles--the role of alkaline phosphatase.

Human placental chorioepithelial brush border membrane, which is in direct contact with maternal blood flow, has platelet aggregation inhibiting activity. In the present study, the mechanism of this action has been examined in relation to ADP (adenosine diphosphate) degrading activity and alkaline phosphatase activity of brush border membrane vesicles (BBMV). BBMV prepared from human early and term placental villi, inhibited platelet aggregation induced by ADP. BBMV had potent ADP degrading (ADPase) activity. ADP was quickly degraded by BBMV. ADP degrading activity of BBMV was not so different between early and term placenta. Alkaline phosphatase activity of late placental BBMV was about three times greater than that of early placental BBMV. On the other hand, ADP degrading activity of late placental BBMV was almost the same as that of early placental BBMV. Inhibiting activity of platelet aggregation induced by ADP and ADP degrading activity of BBMV, were not inhibited by levamisole (alkaline phosphatase inhibitor).

Adenosine Diphosphate↗
PubMed1994

Elevated serum levels of IgE-binding factor/soluble CD23 in bullous pemphigoid.

IgE-related abnormalities and impaired B cell function have been reported in patients with bullous pemphigoid (BP). CD23 is a low affinity Fc epsilon RII on haematopoietic cells and its soluble form (sCD23) is involved in B cell growth and differentiation. In order to determine the role of CD23 in the pathomechanisms of BP, the present study assayed the level of sCD23 in sera of BP patients using an ELISA method. Levels of sCD23 were elevated in BP patients compared with mean levels in the sera of normal control. Furthermore, the increase in sCD23 levels correlated with the degree of disease activity. A significant correlation was found between sCD23 and serum IgE levels in BP sera, but not in normal control sera. These results suggest that sCD23 is an important index for monitoring BP with respect to IgE-related abnormalities and impaired B cell function.

Animals↗
PubMed1994

Insulin-induced hypoglycemia stimulates gluconeogenesis from 14C-lactate independently of glucagon and adrenaline releases in rats.

Correlation between blood glucose, glucagon and adrenaline levels and gluconeogenesis was studied during the recovery from insulin-induced hypoglycemia in rats. Rats, overnight fasted, were intravenously injected with 40 microCi/kg of [U-14C]-lactate and 1 U/kg of porcine insulin under an anesthesia with pentobarbital sodium. Blood samples were drawn via the peripheral vein at 0, 5, 10 and 20 min. Plasma insulin level was 617 +/- 115 microU/ml at 5 min. Plasma glucose level was significantly decreased at 5 min (2.7 +/- 0.3 mM at 5 min v.s. 4.3 +/- 0.2 mM at 0 min, P < 0.01). Plasma glucagon and adrenaline did not significantly respond at 5 min, and then rised. Specific radioactivity of plasma [1-14C]-glucose was significantly higher at 5 and 10 min in the insulin-injected rat than the saline-injected rat (204 +/- 34 v.s. 130 +/- 14 d.p.m./mumol at 5 min, P < 0.01; 275 +/- 32 v.s. 186 +/- 16 d.p.m./mumol at 10 minm P < 0.01). These results suggest that lowering of blood glucose level stimulates gluconeogenesis independently of the release of counter-regulatory hormones in insulin-induced hypoglycemia.

Animals↗
PubMed1994

Leukotriene A4 hydrolase in human skin.

The biochemical properties and immunohistochemical localization of leukotriene (LT) A4 hydrolase were investigated in human skin. The activity of LTA4 hydrolase, which catalyzes the hydrolysis of LTA4 to LTB4, the most chemotactic compound known, was detected in the 100,000 x g supernatant of homogenates of human epidermis and a transformed epidermal cell line (HSC-1). No significant LTA4 hydrolase activity was detected in human whole skin or dermis. The enzymatic properties of LTA4 hydrolase isolated from human keratinocytes and peripheral leukocytes were similar. Their activities were inhibited by bestatin and captopril, and they were completely absorbed by anti-human LTA4 hydrolase antibody. By immunoblotting analysis using this antibody, LTA4 hydrolase was detected as a 70-kDa protein in human epidermis and HSC-1 and was found to be similar to the enzyme detected in peripheral mononuclear leukocytes. In human dermis, LTA4 hydrolase was barely detected by Western blotting. On the other hand, LTA4 hydrolase was demonstrated in the cytoplasm of keratinocytes in the epidermis, and in fibroblasts, infiltrating and endothelial cells in the dermis of normal human skin by immunohistochemical analysis using the immunoperoxidase method. These results suggest that LTB4 can be generated from LTA4 by LTA4 hydrolase in keratinocytes as well as fibroblasts, infiltrating and endothelial cells in the dermis of human skin.

Blotting, Western↗
PubMed1994

Detection of bacteria in phagocyte-smears from septicemia-suspected blood by in situ hybridization using biotinylated probes.

We report herein the detection of intracellular bacteria in phagocyte-smears obtained from septicemia-suspected blood samples by in situ hybridization. This was obtained by using nick-translated biotin-11-dUTP-labeled DNA probes and streptavidin-alkaline phosphatase conjugates for visualization of the hybridized signals. The probes were made from random genomic DNA clones of bacteria which are frequently the causative agents of bacteremia, such as Staphylococcus spp., Pseudomonas aeruginosa, Enterococcus faecalis, Escherichia coli, Klebsiella spp. and Enterobacter spp. When our in situ hybridization method was compared with conventional culture protocols for the ability to detect bacteria from the blood of patients suspected of having septicemia, 30 positive results were obtained in 50 specimens by in situ hybridization methods. In contrast, only 7 positive results were obtained by blood cultures. Thus, even if bacteria cannot be detected by conventional blood cultures and histology, our in situ hybridization method allows for direct observation of bacterial foci in circulating phagocytes and identification of the bacteria. Our investigations suggest that in septicemia, circulating polymorphonuclear neutrophils carry some surviving bacteria as well as metabolized bacterial DNA and RNA for a considerable period of time. Thus, our in situ hybridization method using the phagocyte-smears have diagnostic value for detecting most bacteria which cause septicemia.

Bacteremia↗
PubMed1994

Adult T-cell leukaemia/lymphoma featuring a large granular lymphocyte leukaemia morphologically.

A 70-year-old man from an endemic area of human T-cell lymphotropic virus type I (HTLV-I) developed rapid generalized lymphadenopathy and abdominal tumours. The white blood cell count was 198.3 x 10(9)/l with 93% lymphocytes, 66.3% of which expressed large granular lymphocytes (LGLs). Bone marrow and lymph nodes were also infiltrated by LGLs. Surface markers were positive for CD4, CD25 and HLA-DR, and negative for CD3, CD8, CD16, CD56 and CD57. A monoclonal integration of HTLV-I proviral DNA was demonstrated on these LGLs by Southern blot hybridization analysis. This fact indicates that some adult T-cell leukaemia/lymphoma may morphologically present LGL leukaemia.

Aged↗