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Biomedical subjects

S Fukuda

Publications and source records attributed to S Fukuda.

At least 613 records · Page 34Linked to original sources
PubMed1989

Prostaglandin E1 modifies porcine cerebral arterial tone through cyclooxygenase related eicosanoid(s) release.

The effects of prostaglandin E1 (PGE1) on porcine cerebral arteries were studied in the absence and presence of cyclooxygenase inhibitors, 5 x 10(-6) M indomethacin or 10(-4) M aspirin. In preparations placed at a resting tension, 3 x 10(-9) to 10(-6) M PGE1 caused dose-dependent contractions. In prostaglandin F2 alpha (PGF2 alpha)- contracted preparations, low concentrations of 10(-9) and 3 x 10(-9) M PGE1 did not modify arterial tone and higher concentrations of 10(-8) to 10(-6) M PGE1 further increased the arterial tone in all preparations tested. In contrast, in the presence of the cyclooxygenase inhibitors, low concentration of 10(-9) and 3 x 10(-9) M PGE1 markedly decreased the arterial tone induced by PGF2 alpha and higher dose of 10(-8) to 10(-6) M PGE1 increased the arterial tone in 15 of 18 preparations (83%). These findings suggest that PGE1 modifies porcine cerebral vascular tone at least partly through cyclooxygenase-related eicosanoid(s) production.

Animals↗
PubMed1989

A cytokine, lymphocyte blastogenesis inhibitory factor (LBIF), arrests mitogen-stimulated T lymphocytes at early G1 phase with no influence on interleukin 2 production and interleukin 2 receptor light chain expression.

The function of a human cytokine, lymphocyte blastogenesis inhibitory factor (LBIF), was characterized. To this end, LBIF was purified from crude supernatant of U-937 cells, a human macrophage-like cell line, by using fast protein liquid chromatography (FPLC). We demonstrated here that (a) the LBIF preparation completely inhibited phytohemagglutinin (PHA)-stimulated T cell proliferation; (b) however, in PHA-stimulated T lymphocytes LBIF inhibited neither interleukin (IL)2 production nor the expression of IL2 receptor (IL2R) light chain (CD25) which play a critical role for T cell proliferation; (c) LBIF arrested PHA-stimulated T lymphocytes at the G1 phase of cell cycle and inhibited entry into S phase, thus inhibiting lymphocyte proliferation. Wright-Giemsa's staining of the cells showed that PHA/LBIF-stimulated cells were arrested in early G1. In agreement with this result, LBIF strongly inhibited PHA-induced RNA synthesis. Further, LBIF inhibited the induction of the transferrin receptor which is normally expressed at the late G1 phase of the cell cycle. The inhibitory activity of LBIF was reversible. Thus, this study elucidated that LBIF arrests PHA-stimulated T lymphocytes at a point between the stages of IL2 production or IL2R light chain expression (in early G1) and transferrin receptor expression (in late G1). Taken together, these results suggest that there might be a control system of T cell proliferation distinct from the previously reported mechanisms, such as the inhibition of IL2 production or the inhibition of IL2R light chain (CD25) expression, and that LBIF might be an important molecule in the regulation of normal lymphocyte proliferation.

Biological Factors↗
PubMed1989

Studies of Panax japonicus fibrinolysis.

The effects of a 70% methanol extract (PMe) obtained from the rhizomes of Panax japonicus C. A. Meyer on experimental thrombosis and fibrinolysis were investigated in vivo and in vitro. PMe showed a promotive effect on the activation of the fibrinolytic system as determined by the euglobulin lysis time (ELT) assay but was inactive to the inhibitory effect against endotoxin-induced disseminated intravascular coagulation (DIC) in rats. PMe and its major components, chikusetsusaponin III, IV, and V, strongly promoted the action of urokinase in fibrin plate. These results suggested that PMe promotes the fibrinolysis and its effective components are chikusetsusaponin III, IV, and V.

Animals↗
PubMed1989

Structures of the sugar chains of interferon-gamma produced by human myelomonocyte cell line HBL-38.

Interferon-gamma produced by the human myelomonocyte cell line HBL-38 contained galactose, mannose, fucose, N-acetylglucosamine, and N-acetylneuraminic acid as sugar components. Sugar chains were liberated from interferon-gamma by hydrazinolysis. Free amino groups of the sugar chains were acetylated and the reducing-end sugar residues were tagged with 2-aminopyridine under new reaction conditions in which no sialic acid residue was hydrolyzed. The pyridylamino (PA-) derivatives of the sugar chains thus obtained were purified by gel filtration and reversed-phase HPLC. Seven major PA-sugar chains were isolated and the structure of each purified PA-sugar chain was identified by stepwise exoglycosidase digestion and 500-mHz 1H-NMR spectroscopy. The results indicated that the structures of the major PA-sugar chains were of the biantennary type, to which 0 to 2 mol of fucose and 1 to 2 mol of N-acetylneuraminic acid were linked as shown below. (formula; see text)

Asialoglycoproteins↗
PubMed1989

Tolerance to N2O-induced alterations in somatosensory evoked potentials.

The effect of nitrous oxide (N2O) on somatosensory evoked potentials from the cortical (CEP) and spinal cord (SCP) regions in response to forepaw stimulation was studied in ketamine-anesthetized and mechanically ventilated rats. The CEP was recorded from the skull over the contralateral somatosensory area; the SCP was recorded from the supraspinous ligament at C57-6 and L1-2 levels of the spine. Rats were exposed to 70% N2O for 5 h, whereupon N2O was withdrawn for 2 h. Thereafter, the rats were re-exposed to N2O for 10 min. The N13-P21 component of the CEP, the slow positive wave (P2) of the segmental SCP, and the heterosegmental positive cord dorsum potential (HSP) were significantly suppressed by N2O, while the large negative (N1) component of the segmental SCP remained unchanged. A partial recovery of the CEP and HSP was observed during the 5 h of N2O anesthesia, while significant recovery of the P2 component of the SCP was not observed. The withdrawal from N2O following 5 h exposure caused an augmentation of the CEP (When compared to the control values). Re-exposure of rats to N2O again caused the suppression of these potentials as in the initial exposure. The results suggest that the phenomenon of tolerance to N2O in terms of evoked potentials develops within 5 h in the brain but not in the spinal cord.

Journal Article↗
PubMed1989

Involvement of sialic acid in high-affinity binding of quaternary ammonium compounds by brush border membrane from rat intestine.

As one approach to clarify the absorption mechanisms of quaternary ammonium compounds (QACs), their binding characteristics have been studied using brush border membrane vesicles isolated from rat small intestine and liposomes composed of phospholipid and GM3 ganglioside. The binding of propantheline was significantly decreased when the vesicles were pretreated with neuraminidase. Propantheline and methochlorpromazine bound to the liposomes, the binding for the latter drug being significantly greater than that for propantheline. When GM3, isolated from rat small intestine, was incorporated into the liposomes their binding capacity for both drugs increased significantly. It is suggested that the binding of QACs to the lipid layer and sialic acid play a role in the high binding of drugs to the intestinal brush border membrane. Furthermore, a sensitive and reproducible high-performance liquid chromatographic method for sialic acid has been developed.

Animals↗
PubMed1989

Thirty-one autopsy cases of trisomy 18: clinical features and pathological findings.

The clinical features and morphological findings in 31 Japanese infants with trisomy 18 are presented. The majority were small-for-date infants. There was no sex predominance in our series, as opposed to male:female ratios of 1:3 reported in the literature. The average age at death was greater in females than in males. Cardiovascular anomalies were consistently present; ventricular septar defect and patent ductus arteriosus being the most common malformations. Various other internal malformations including the Arnold-Chiari malformation were observed.

Autopsy↗
PubMed1989

[Activity of serum arylsulfatase B in nasal allergy patients].

Although the arylsulfatase B has been reported to inactivate slow reacting substance of anaphylaxis (SRS-A) in vitro there has not been studied about the relation between this enzyme and nasal allergy in vivo. The present study was done to examine the serum level of arylsulfatase B in 73 nasal allergy patients and 13 normal controls. Serum arylsulfatase activity was quantified by measurement of the hydrolysis product (p-nitrocatechol) generated by the interaction of this enzyme and a substrate (p-nitrocatechol sulfate, Sigma). The results are summarised as follows; 1. Arylsulfatase B activity is significantly elevated in sera of nasal allergy patients than in that of normal subjects. 2. There are no correlation between the enzyme activity and the number of peripheral blood eosinophiles. 3. There is tendency the severe the nasal obstruction, the lower the level of the enzyme activity.

Chondro-4-Sulfatase↗
PubMed1989

Endocytic pathway of high density lipoprotein via trans-Golgi system in rat resident peritoneal macrophages.

Interaction of high density lipoprotein (HDL) with rat resident peritoneal macrophages was investigated by morphological and biochemical approaches. Binding studies at 0 degree C demonstrated saturable binding sites for 125I-HDL on the surface membrane. When cells were incubated with 125I-HDL at 37 degrees C, the cell-associated radioactivity increased with time, but intracellular degradation of HDL did not occur. Rather, the cell-associated 125I-HDL was released intact into the medium. Two morphological probes were employed to visualize the post-binding fate of HDL. Horseradish peroxidase and ferritin conjugates of HDL showed specific bindings to the coated pits of the plasma membranes and were internalized and delivered through receptosomes to a trans-Golgi system. They were then resecreted as secretory vesicles from the cells. Parallel experiments with transferrin-horseradish peroxidase conjugates revealed an endocytic pathway identical or very similar to that observed with HDL. These results provide evidence that internalization and subsequent nonlysosomal pathway via the trans-Golgi system are involved in receptor-mediated endocytosis of HDL by macrophages.

Animals↗
PubMed1989

[Prophylactic use of cefpiramide (CPM) in open heart surgery].

The concentration of cefpiramide (CPM) in serum and myocardial tissues was measured in 24 patients with open heart surgery. The regimen was given in bolus of 2 g intravenously before the commencement of cardiopulmonary bypass. Blood and tissues of the right atrial appendage and pericardium were surveyed for samples at an estimated interval after the administration of CPM. The concentration of CPM in the blood and the myocardial tissues were consistently efficacious for both gram positive and negative bacterium. The duration and dosage of CPM, selected in the study, were both satisfactory for prevention of infection in open heart surgery.

Adolescent↗
PubMed1989

[Relapse of gingival tumor during hematological remission in acute promyelocytic leukemia].

A 56-year-old man was admitted to the hospital in April, 1986, with the chief complaint of fatigue. The diagnosis of acute promyelocytic leukemia (APL) was made based on the proliferation of atypical promyelocytes in the bone marrow. No gingival swelling was found on admission. A complete remission was achieved by the BHAC-DMP therapy and maintained by the consolidation therapy and the intensification therapy. In July, 1987, he noticed a solitary gingival tumor around the left lower second molar. The biopsy showed the massive infiltration of leukemic cells, despite the hematological remission. Combination chemotherapy was not effective but the tumor disappeared by irradiation. A hematological relapse occurred in November, 1987, but the second complete remission was achieved by the AB-triple V therapy. He died because of the second hematological relapse in July, 1988. Along with the wide use of intensive chemotherapy for acute leukemia, tumor forming leukemia during the hematological remission, as seen in this case, would be increasing. Thus, we should not overlook any newly formed tumor in the treatment of leukemia.

Aclarubicin↗
PubMed1989

[Early duodenal cancer of the bulb--report of a case].

A 70-year-old woman was referred for an evaluation of evidence indicating occult bleeding found in the feces and epigastralgia. Radiologic and endoscopic examinations disclosed a duodenal polyp at the bulb. A pathological examination of a biopsied specimen revealed a well-differentiated adenocarcinoma. The patient underwent a gastrectomy and an extensive duodenectomy, and the surgical specimen examined indicated a pedunculated polyp (1.0*2.0) at the duodenal bulb which, histologically, consisted of two distinct parts: one, a tubular adenocarcinoma, and the other, non-tumorous tissue. Most of the lesion was the former, whereas the latter was found at the bottom and at the stalk of the polyp, and consisted of hyperplastic foveolar structures with gastric type cells and pyloric type glands. The histological findings of the mucosa, which was clearly duodenal around the root of the polyp, indicated that the carcinomatous portion was confined to the mucosal layer. These findings indicate that the adenocarcinoma in this case originated from a duodenal polyp composed of aberrant gastric mucosa. Also included in this study is a review of 57 cases of early duodenal cancer of the bulb, that have been reported in Japan.

Adenocarcinoma↗
PubMed1989

[Experimental studies of prolonged circulatory maintenance with a left ventricular assistance in cardiac arrested goats].

Recently, various types of left ventricular assist systems (LVAS) have become available to treat the patients in profound heart failures beyond the limit of the effects of IABP. However, the occurrence of an intractable severe bi-ventricular failure, ventricular fibrillation (VF) or cardiac arrest during the time with left ventricular assistance became a more serious problem. Since during the usage of these assist devices, pulmonary venous return will decrease, consequently, LVAS will not be able to maintain sufficient systemic circulation over a extended duration. This study was intended to develop a method of prolonged circulatory maintenance only with a LVAS in cardiac arrested goats until the time when heart transplantation will be performed. In this study, our LVAS was implanted between the left atrium and the aorta in twelve goats in which the hearts were fibrillated. We have followed the principle of circulatory maintenance only with our LVAS in cardiac arrest based on the pressure gradient between the right and left atria and at the same time the pump suction effect through the lungs. The results showed that when pulmonary vascular resistances (PVRs) were kept within normal ranges (less than 15,000 dynes.sec.cm-5), systemic circulations were well maintained only with LVAS as long as RAPs were kept in 14-18 mmHg. Under these conditions, the systemic circulatory flows have fluctuated between 80-140 ml/kg/min depending on the animals demands. The mean arterial pressures were kept above 80 mmHg and the goats have shown quite normal behaviors. However, in goats which showed the presence of pleural effusions and ascites were found to be more difficult to maintain prolonged normal circulation. In our study, the maintenance of total serum protein level above 6.0 g/dl was found to be essential to prevent the development of both pleural effusions and ascites . The authors have achieved the longest survival goat for a duration of 38 days after implantation with our LVAS. We have concluded that when PVRs may be kept in normal ranges, our LVAS can maintain normal systemic circulation even in arrested hearts for a prolonged duration during which time heart transplantation or total artificial heart replacement can be performed.

Animals↗
PubMed1989

Prerequisites to salvage profound biventricular failure patients with ventricular assist devices.

We conducted chronic experiments to determine how to treat profound biventricular failure systematically with ventricular assist devices (VADs) and to analyze the factors that affect prognoses for this condition. Anoxic arrest was induced in ten goats by aortic cross-clamping under normothermic conditions (38.5 degrees C) for 30 (n = 3), 45 (n = 1), and 60 (n = 6) minutes. A left ventricular assist device (LVAD) was implanted in eight animals, and a biventricular assist device (BVAD) was used in two. Three goats--two of which had undergone anoxic arrest for 30 minutes and one for 60 minutes--whose right atrial pressure (RAP) was approximately 18 mm Hg during the acute stage, recovered in two to three weeks, and the pumps were successfully removed. Pathological findings in these animals showed scattered areas of surviving myocardium, with connective tissue replacing the degenerated myocardium. The remaining five LVAD goats required higher RAPs to maintain circulation and died from various causes. Maintaining circulation without volume loading, even in the presence of arrhythmias, was easier with the BVAD. One BVAD animal that underwent 45 minutes of anoxic arrest recovered from right ventricular failure, and the right pump was removed. The second goat (anoxic arrest, 60 min) on the BVAD failed to recover. Autopsy of the myocardium revealed a thin ventricular wall. Our studies show that the use of VADs allows time for a failing heart to recover, but the potential for healing is affected by the severity of myocardial damage prior to VAD application.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

[Calcified ventricular septal defects--a surgical case in elderly].

A 60-year-old female with ventricular septal defect was operated upon successfully. Twice episodes of congestive heart failure were preceded to the operation. The defect with massive calcification around it was repaired with direct closure. The postoperative course was uneventful except for transient attacks of atrial fibrillation and asthma. A chronic course with a jet stream and/or probable inflammation in long term period might be considered as a causative factor of calcification around the ventricular septal defect. Surgical procedure, if necessary, is not contraindicated in such cases.

Calcinosis↗