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Biomedical subjects

S Maeda

Publications and source records attributed to S Maeda.

At least 451 records · Page 25Linked to original sources
PubMed1995

Polymorphism and Distribution of Apo(a).

Several apo(a) isoforms, controlled by a series of alleles Lp(a)F, Lp(a)B, Lp(a)S1, Lp(a)S2, Lp(a)S3, Lp(a)S4 and null, were found in 470 healthy Japanese by 4% SDS-PAGE and immunoblotting techniques. There was a strong inverse relationship between the apparent molecular weight of apo(a) isoforms and plasma concentrations of Lp(a). Lp(a) in d < 1.006 fraction increased 2-4h after oral fat load. Lp(a) exhibited a marked avidity for triglyceride-rich lipoprotein (TRL), and we suggest that the TRL-bound Lp(a) is the intact Lp(a) derived from serum. We demonstrated that the lipid-free apo(a) does not contain apo B-100 in serum, and has a molecular mass of ca 200 kDa. The free apo(a) level in normal subjects was 1.75 mg/dl (as Lp(a)) and was no different from the level in CAD patients.

Coronary Disease↗
PubMed1995

[Effects of prostaglandin E1 (PGE1) on pulmonary hypertension and lung vascular remodeling in a rat monocrotaline model of human pulmonary hypertension].

Prostaglandin E1 (PGE1) has been shown to be a potent pulmonary vasodilator in humans and in many animals. The effects of PGE1 on the development of pulmonary hypertension and on pulmonary vascular remodeling were studied in a rat monocrotaline (MCT) model of human pulmonary hypertension. By 3 weeks after injection, MCT (80 mg/kg S.C.) had resulted in high values of mean pulmonary arterial pressure and of the ratio of right ventricular weight to left ventricle+septum weight (RV/LV+S). PGE1 inhibited the development of pulmonary hypertension (300 micrograms/kg) and right ventricular hypertrophy (300 and 100 micrograms/kg) induced by MCT. Three weeks after the injection, the media walls of pulmonary arteries in lungs from rats given MCT were significantly thicker than those from lungs of control rats. PGE1 (300, 100, and 30 micrograms/kg) resulted in significantly less of this morphologic change, in a dose-dependent manner. These results indicate that PGE1 inhibits the development of pulmonary hypertension associated with lung vascular thickening induced by MCT. PGE1 may be useful for the treatment of pulmonary hypertension in humans.

Alprostadil↗
PubMed1995

Long-term maintenance of liver-specific functions in three-dimensional culture of adult rat hepatocytes with a porous gelatin sponge support.

The three-dimensional culture of adult rat hepatocytes with a porous gelatin sponge (gelfoam) support was investigated. Hepatocytes were immobilized on the surface as well as within the pores of the support. The morphology of the hepatocytes immobilized on the support was close to that observed in vivo. In some parts of the support the spheroids of hepatocytes could be observed. To examine the liver-specific functions of the hepatocytes in the culture, the levels of serum albumin and bile acids secreted into the medium were assessed. The secretion of albumin and bile acids was stable over the course of 12 days, longer than that in collagen-gel culture. To elucidate further the function of hepatocytes immobilized on gelfoam, the metabolic activities of the hepatocytes, as measured by the competency of removal of NH4+ and the synthesis of urea nitrogen, were determined. The rates of ammonium removal and urea nitrogen synthesis were comparable with those in conventional monolayer culture. Albumin secretion was enhanced by the treatment of gelfoam with either heparin or acidic fibroblast growth factor (aFGF), the gelfoam having a high affinity for these substances. DNA synthesis was also enhanced by aFGF. These results demonstrate that gelfoam is a suitable support for the in vitro culture of hepatocytes. Combined with its easy manipulation, it is suggested that the culture system described could be used for both basic and applied studies.

Ammonium Chloride↗
PubMed1995

Effect of procaterol, a beta 2-adrenoceptor agonist, on skin whealing response caused by inflammatory mediators in asthmatic children.

BACKGROUND: Beta 2-adrenoceptor agonists have been shown to reduce allergen-induced skin whealing responses via inhibition of mediator release. OBJECTIVE: To study whether beta 2-adrenoceptor agonists have a direct action against inflammatory mediator-induced skin whealing responses. METHODS: We examined the effect of procaterol, a beta 2-adrenoceptor agonist, on skin whealing responses to histamine, platelet-activating factor (PAF), substance P, or bradykinin in eight asthmatic children in a double-blind, randomized, cross-over study. Two hours after taking procaterol (50 micrograms) or placebo orally, the subjects were given these mediators intradermally at a concentration of 10(-5) M. RESULTS: Procaterol has a small but significant inhibitory effect on wheal formation following the intradermal injection of histamine and PAF by an average of 15% (P < .05) and 18% (P < .05) respectively but not against substance P or bradykinin. CONCLUSIONS: Our results suggest that although beta 2-adrenoceptor agonists may have an inhibitory effect against plasma exudation from microvasculature in the human skin, bronchodilatory effects are more prominent.

Adolescent↗
PubMed1995

NAD synthesis from nicotinic acid by the hepatocytes prepared from diabetic rats.

Hepatocytes were prepared from rats 3 and 7 days after a single injection of streptozotocin (50 mg/kg) or alloxan (40 mg/kg). Using the hepatocytes, NAD-and total pyridine nucleotide-syntheses from [carboxyl-14C]-nicotinic acid were investigated. The NAD content of streptozotocin- or alloxan-treated hepatocytes was not significantly different from that of the control hepatocytes. Syntheses of NAD and total pyridine nucleotides from nicotinic acid were significantly elevated 3 days after streptozotocin-injection but only total pyridine nucleotide synthesis was significantly higher 7 days after streptozotocin. Only total pyridine nucleotide synthesis was elevated 3 days after alloxan. Differences in the effects of the two diabetogenic agents and the physiological meaning of an increased NAD synthesis from nicotinic acid in the liver of diabetic animals were discussed.

3-Hydroxybutyric Acid↗
PubMed1995

Cardiac musculature of the cranial vena cava in the common tree shrew (Tupaia glis).

Cardiac musculature of the cranial vena cava in the common tree shrew (Tupaia glis) was examined by light and transmission electron microscopy. The common tree shrew has well developed cardiac myocyte layers in the tunica media of the cranial vena cava, extending from the right atrium to the root of the subclavian vein. Because the common tree shrew belongs to a primitive group of mammals, the occurrence of cardiac musculature in the cranial vena cava may be a common feature in lower mammals. The development of this musculature indicates that active contraction of the cranial vena cava wall occurs in this species. Electron micrographs showed the typical ultrastructure of myocytes and nerve endings. These observations suggest that this musculature may serve as a regulatory pump for the return of venous blood to the right atrium and as a blood reservoir system under conditions of rapid heart rate. Additionally, the presence of atrial natriuretic polypeptide (ANP) was also demonstrated in the myocytes of the vena cava immunohistochemically. These findings show that the cardiac endocrine organ for ANP develops even in the principal veins including the cranial vena cava.

Animals↗
PubMed1995

Development of skeletal metastases.

Skeletal metastases result from a series of complex steps including activation of osteoclasts and interaction between adhesion molecules on cancer cells and bone matrices. Researchers of this study used pathologic specimens of breast cancer cells from primary and metastatic sites obtained at surgery or autopsy to demonstrate the expression of parathyroid hormone-related protein by immunohistochemistry and beta 3 integrin by in situ hybridization to clarify the role of tumor-derived osteoclast activating factors and adhesion molecules in the development of skeletal metastases. The results of this retrospective study showed a significant difference of parathyroid hormone-related protein and beta 3 integrin expression in cases with and without skeletal metastases. These expressions were enhanced or clonally selected or both in skeletal metastatic sites. Because activation of osteoclastic bone resorption by parathyroid hormone-related protein could facilitate tumor cells to attach to the eroded bone surface through cell adhesion molecules, these 2 factors could make it easier for tumor cells to grow in bone.

Adult↗
PubMed1995

[Changes of tympanic temperature by stellate ganglion block].

The effects of stellate ganglion block (SGB) on the temperature of tympanic membrane were determined clinically. Thirty patients received SGB with 8 ml of 1 % mepivacaine. The tympanic temperature was measured using radiation non-contact tympanic membrane thermometer before and after administration of SGB for 30 min on the side where SGB was given. Before SGB the tympanic temperature was 37.29 +/- 0.08 degrees C, and there was no difference in the readings between the two sides. The tympanic temperature dropped significantly 5 min after SGB and reached its lowest value of 36.90 +/- 0.08 degrees C 15 min later. This drop persisted for more than 30 min after SGB. The fact that therapeutic effect of SGB is partly due to vasodilation and improvement in blood flow to the affected region was demonstrated, but these effects in internal carotid arterial system have not yet been studied in detail. Tympanic temperature has been proposed as a valid index of brain temperature in man. The mechanism of brain cooling has been suggested that countercurrent heat exchange takes place between carotid and jugular blood flow. Therefore the result of the study suggests that SGB could enhance an increase in the brain blood flow.

Adolescent↗
PubMed1995

Marked bilateral atrial dilation of unknown cause.

Four elderly women with marked bilateral atrial dilation but no evidence of significant structural or functional cardiac abnormalities other than atrial fibrillation are described. All patients demonstrated severe cardiomegaly on chest radiographs. Three patients have remained in good condition during the follow-up of 6 to 16 years except for occasional edema or pleural effusion, which was easily treated with diuretics and/or digitalis. The other patient had had only one episode of pleural effusion and leg edema at age 90 years before she died of colon cancer at age 100 years.

Aged↗
PubMed1995

[A case of lung metastasis from renal cell carcinoma showing complete response by a combination chemotherapy with methotrexate, vinblastine and pepleomycin (MVP)].

A 69-year-old woman visited our hospital with complaints of low grade fever and general fatigue in October 1990. Computed tomography (CT), ultrasonogram, and renal arteriography showed left renal tumor and she was diagnosed with renal cell carcinoma (T2M0N0). Left radical nephrectomy was performed in December 12, 1990. After operation, 3 x 10(6) unit per day of IFN-alpha were administered three times per week. She complained of low grade fever and general fatigue in June, 1991. CT showed left lung metastasis (phi 3 cm). She was given combined chemotherapy (MVP: methotrexate, vinblastine, pepleomycin). After 2 courses, lung metastasis decreased and after 4 courses, lung metastasis was not shown by CT in December, 1992. No evidence of relapse was shown by CT in June, 1994.

Aged↗
PubMed1995

[Clinical evaluation of chemohormonal therapy as an initial treatment for stage D2 prostatic cancer--effect of UFT administration combined with hormonal therapy].

We evaluated the usefulness of hormonal therapy combined with UFT as initial treatment in comparison with hormonal therapy alone in 92 patients with Stage D2 prostatic cancer treated at the Department of Urology, Dokkyo University School of Medicine between 1974 and 1993. Twenty-six of these patients were treated with diethylstilbestrol diphosphate (DESP) and castration (hormonal therapy alone group), and 23 patients were treated with UFT, DESP and castration (UFT combined therapy group). The 5-year survival rates calculated with Kaplan-Meier's method in the hormonal therapy alone group and the UFT combined therapy group were 34.6 % and 38.3%, respectively. However, the 3-year survival rates of pathologically poorly differentiated adenocarcinoma in these groups were 30.0% and 50.0%, respectively. Based on these results, it was suggested that UFT administration combined with hormonal therapy is useful for pathologically poorly differentiated adenocarcinoma in Stage D2 prostatic cancer.

Adenocarcinoma↗
PubMed1995

Plasma endothelin-1 levels after exercise in patients with congenital heart disease.

We have previously reported that plasma endothelin-1 (ET-1) levels were significantly increased after exercise in healthy athletes. In the present study, venous plasma ET-1 levels were measured to investigate whether the role of ET-1 during exercise differs between healthy athletes and patients with congenital heart disease. Seven patients (mean age 13 years) performed symptom-limited treadmill exercise (Bruce protocol). All patients were in class I of the NYHA functional classification. The mean end-exercise O2 utilization was 32 ml/min/kg (166% of ventilatory threshold). Blood sampling was carried out in the seated position. The plasma ET-1 level was 1.21 pg/ml before exercise and did not alter immediately after or 30 min after exercise. The plasma level of norepinephrine was markedly elevated immediately after exercise and returned to the basal level 30 min after exercise. The present study demonstrated that exercise failed to alter plasma ET-1 levels in patients with congenital heart disease.

Adolescent↗
PubMed1995

[Matrix metalloproteinase (MMP-9) in patients with rheumatoid arthritis].

MMP-9 degrades type IV collagen, gelatin, type V collagen, and type XI collagen. We measured proMMP-9 and proMMP-9/TIMP-1 complex in sera and joint fluids by sandwich ELISA, and examined immunohistochemically the expression of these proteins in joint tissue from patients with rheumatoid arthritis (RA). ProMMP-9 was purified by the three chromatographic steps from the culture medium of HT1080 cells. Purified proMMP-9 and activated MMP-9 by APMA showed a single band of Mr92000, Mr67000, resectively on gelatin-zymography. We raised two monoclonal antibody colones 2G9, 8G7 against proMMP-9 with BALB/c mice. 2G9 and 8G7 reacted with proMMP-9 on Western blotting, and these clones reacted proMMP-9 and proMMP-9/TIMP-1 complex on sandwich ELISA, specifically. ProMMP-9 concentration in 86 sera (749.4+/-940.2 ng/ml) and 54 joint fluids (4539.9+/-7681.5 ng/ml) from patients with RA was significantly higher than those of patients with osteoarthritis and control. Immunohistochemistry with 2G9 showed that in rheumatoid synovium proMMP-9 localized in neutrophils and monocytes diffusely infiltrated the sublining layer. In addition, osteoclasts in rheumatoid subchondral bone were intensively stained. ProMMP-9 concentration in joint fluids from 39 RA patients was not correlated to stage and class of Steinbrocker and to clinical laboratorial data. But, it was positively correlated to the number of proMMP-9 positive cells in RA synovium (r=0.607) and the score of Roony's diffuse infiltrates of lymphocytes (r=0.720). Our results suggest a role of MMP-9 in joint destraction of RA throughout neutrophils and monocytes, and a regulation of this enzyme by lymphocytes.

Adult↗
PubMed1995

Epstein-Barr virus DNA in nasopharyngeal carcinoma in Thai patients at Ramathibodi Hospital, Bangkok.

Nasopharyngeal carcinoma (NPC) is one of the most common malignancies in Thailand. The association of Epstein-Barr virus (EBV) and NPC, especially undifferentiated type, has been documented. There is, however, conflicting evidence with regard to the squamous cell type. We have therefore investigated EBV-DNA in all the three types of NPC to assess the association of EBV and NPC in Thai patients. EBV-DNA was detected in formalin-fixed paraffin-embedded tissues from the patients of Ramathibodi Hospital, Bangkok using polymerase chain reaction. A primer pair that amplified EBV nuclear antigen gene was used in the reactions and the amplification products were hybridized with a specific EBV probe. EBV-DNA was identified in 24 of 28 of tissue samples from patients with undifferentiated NPC, 25 of 40 samples from patients with squamous cell NPC and 3 of 4 samples with nonkeratinizing NPC. None of 12 nasopharyngeal tissue samples without NPC contained detectable EBV-DNA. Our results indicated a strong association of EBV with undifferentiated as well as non-keratinizing NPC. EBV-DNA was demonstrated in most cases of squamous cell NPC but the association of EBV in this type of carcinoma was not as frequent as in the other two types of NPC.

Base Sequence↗
PubMed1995

DNA resynthesis and binucleated metamorphosis in cardiac muscle cells after isoproterenol-induced injury: bromodeoxyuridine immunohistochemistry.

In this study, we assessed reactive DNA synthesis in mouse cardiac myocytes after injury in vivo using the Bromodeoxyuridine (BrdU) immunohistochemical method and clarified binucleated metamorphosis of S-phase cardiac myocytes in the myocardial healing process. The animals were injured by isoproterenol i.p., and studied 0, 1, 2, 3, 5 and 10 days after injury. Each animal was killed 3 hr after labeling with BrdU i.p. The BrdU labeling index was calculated 0, 1, 2, 3, 5 and 10 days after injury. Moreover, we observed the morphological difference of S-phase cardiac myocytes between Group A and Group B (A and B group were killed 3 hr and 3 days, respectively, after BrdU i.p.). Most of BrdU positive cells were mesenchymal fibroblastic, and BrdU positive cardiac myocytes were a minor phenomenon during healing process. In cardiac myocytes, the BrdU labeling index is 0.49 +/- 0.02 and 0.05 +/- 0.01 at day 3 and 0 after injury, respectively (P < 0.05). All BrdU positive cardiac myocytes were located around myocardial necrosis. All BrdU positive myocytes in Group A were mononucleated, whereas some were binucleated in Group B. These results indicated that some of the cardiac myocytes could synthesize DNA reactively even after birth, and that in a healing process, myocytic DNA synthesis is probably followed by binucleated metamorphosis.

Animals↗