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Biomedical subjects

S Fukuda

Publications and source records attributed to S Fukuda.

At least 469 records · Page 26Linked to original sources
PubMed1994

Hypoxia modifies the vasodilatory effects of nitroglycerin, prostaglandin E1, and hydralazine on isolated porcine coronary arteries.

To evaluate the potency of vasodilatory drugs in hypoxia, we studied the effects of nitroglycerin (NTG), prostaglandin E1 (PGE1), and hydralazine on porcine coronary artery constricted with endothelin-1 (ET-1) in both oxygenated and hypoxic conditions. Removal of endothelium potentiated NTG-induced relaxation in oxygenated conditions. Hypoxia potentiated relaxation of endothelium-intact arteries induced by NTG, but not relaxation of endothelium-denuded arteries. These findings suggest that hypoxia may modify endothelial function in NTG-induced relaxation. The relaxation of endothelium-intact and -denuded arteries induced by PGE1 in hypoxia was significantly greater than that in the oxygenated condition. PGE1 significantly increased the content of cyclic AMP in the hypoxic condition; it was much greater than that in the oxygenated condition, suggesting that hypoxia may enhance PGE1-induced relaxation by increasing cyclic AMP levels. Hypoxia attenuated hydralazine-induced relaxation in both endothelium-intact and denuded arteries. Indomethacin and aspirin attenuated hydralazine-induced relaxation in the oxygenated condition, suggesting that cyclooxygenase-related eicosanoid(s) may be involved in hydralazine-induced relaxation. However, indomethacin did not alter relaxation of hypoxic arteries induced by hydralazine. These findings suggest that hypoxia may inactivate cyclooxygenase in hydralazine-induced relaxation. Hypoxia may greatly modify the action of vasodilators on porcine coronary smooth muscle.

Alprostadil↗
PubMed1994

Role of endogenous vasopressin in development of gastric ulcer induced by restraint and water immersion.

To elucidate the role of arginine vasopressin (AVP) in the development of stress-induced gastric ulcer, the mucosal lesions after restraint and water immersion were examined in Brattleboro strain rats with hereditary hypothalamic diabetes insipidus (DI) and in Long-Evans rats (LE) used as controls. Restrained animals were immersed in water for 2 h, and the size of lesion was expressed as percentage of the lesion area to the total glandular mucosal area, which were defined as ulcer index (UI). In DI rats, UI was significantly higher than in control LE rats, despite the attenuated responses of plasma adrenocorticotropic hormone (ACTH) to stress. Although subcutaneous injection of selective antidiuretic analogue 1-desamino-8-D-AVP did not affect UI, intracerebroventricular (icv) administration of AVP reduced UI in DI rats, and icv administration of V1 antagonist [d(CH2)5Tyr(Me)]AVP elevated UI in LE rats. These results indicate that endogenous AVP plays a role in preventing the formation of gastric ulcers induced by stress via a central V1 receptor. Furthermore, we suggest that elevation of ACTH in plasma is not essential in the development of stress-induced gastric ulcer in rats.

Adrenocorticotropic Hormone↗
PubMed1994

Interferon-gamma induces interleukin-3 release from peripheral blood eosinophils.

Interferon-gamma (IFN-gamma) upregulates eosinophil effector functions and prolongs the in vitro survival of eosinophils. We examined the possible capacity of IFN-gamma to stimulate eosinophils to produce eosinophil-activating cytokines. Eosinophils purified from mild atopic volunteers were cultured with 100 U/ml IFN-gamma. Viability of eosinophils was counted and supernatants were tested for the presence of cytokines by neutralization of eosinophil viability-enhancing activity with specific antibodies to IFN-gamma, interleukin-5 (IL-5), IL-3, or granulocyte-macrophage colony-stimulating factor (GM-CSF). IFN-gamma-enhanced eosinophil viability was up to 95% on the 4th day of culture. Pretreatment with anti-IL-3 antibody partially blocked the IFN-gamma-enhanced eosinophil survival. IFN-gamma-stimulated eosinophil supernatants had eosinophil survival. IFN-gamma-stimulated eosinophil supernatants had eosinophil viability-enhancing activity that was blocked by pretreatment not only with anti-IFN-gamma but also with anti-IL-3. Antibodies to IL-5 or GM-CSF did not have the blocking effect. To further confirm the production of IL-3 by eosinophils, we performed reverse transcription polymerase chain reaction (RT-PCR) for IL-3 messenger RNA (mRNA) in IFN-gamma-stimulated eosinophils. Significant IL-3 mRNA expression in eosinophils was observed at 6 h of incubation with IFN-gamma. These results suggest that IFN-gamma stimulates the autocrine function of eosinophils and may play an important role in allergic inflammation.

Cell Survival↗
PubMed1994

Lung retention of Pu following inhalation of PuO2 in rats measured using a whole body counter.

A lung retention function on the amount of PuO2 in rats was determined. Five rats were exposed to polydisperse aerosols of PuO2 having a size of 0.47 micron activity median aerodynamic diameter. The initial lung burden was between 1990 Bq and 2960 Bq. Instead of serial-sacrifice study, in vivo counting of low energy L X-rays with thin NaI(Tl) scintillation detectors was used to follow the lung retention of Pu at various intervals up to 468 days after inhalation. The calibration of this counting system was made by measuring lung activity of rats sacrificed for other experimental purposes. It was confirmed that the potential skin contamination and the Pu translocated to the other organs was not counted at the present counting geometry. Our results showed that 77% of PuO2 deposited deep in the lung was cleared with a half-time of 53 days, whereas the residual 23% stayed there for a longer period (a half-time of 795 days).

Administration, Inhalation↗
PubMed1994

High incidence of malignant lung carcinomas in rats after inhalation of 239PuO2 aerosol.

Female Wistar strain rats were exposed to a single inhalation of a submicron-size aerosol of high-fired 239PuO2 to investigate pulmonary carcinogenesis during lifespan periods. The absorbed lung doses of the exposed animals ranged from 0.6 to 12 Gy and were well correlated with the initial lung deposition (ILD) of 0.1 to 2.3 kBq. Survival and induction of primary lung tumors in 116 exposed rats were compared with those in 56 untreated control rats in respect to lung doses received. Mean survival time was greatly reduced, and the cumulative incidence of total lung tumors was markedly increased to 90-100% in rats that received more than 4 Gy, whereas of the controls only one animal (1.8%) died of primary lung tumors. Primary but benign adenomas were present in exposed animals given 1.0 Gy or less, and the incidence of adenomas was 22-25% at 4-5 Gy, but decreased sharply to 3-5% at 6-8 Gy. In contrast, no malignant carcinomas, including adenocarcinomas, adenosquamous carcinomas and squamous cell carcinomas, developed at a dose of less than 1.0 Gy, whereas they were present in 75% or more of the rats given 4-10 Gy, but only in 55% at 12 Gy. Although there were no clear differences in the dose and time required for induction among the carcinoma types, all tended to develop in earlier periods after inhalation than adenomas. Despite the limited number of exposed animals that received lower doses, results suggest that malignant lung carcinomas are highly and early induced and have a different dose-effect relationship than benign adenomas at doses of more than 1 Gy after inhalation exposure to 239PuO2.

Adenocarcinoma↗
PubMed1994

Preparation and characterization of anti-fumonisin monoclonal antibodies.

Murine monoclonal antibodies were prepared against fumonisin B1-carrier protein conjugates, such as fumonisin B1-ovalbumin and fumonisin B1-keyhole limpet hemocyanin. Five stable hybridoma clones were obtained. The response ranges of these monoclonal antibodies for fumonisin B1 were from 10 to 1000-5000 ng/ml in the competitive indirect enzyme-linked immunosorbent assay (CI-ELISA).

Animals↗
PubMed1994

Changes in histomorphometric values of iliac trabecular bone and serum biochemical constituents related to bone metabolism in beagle dogs during growth.

Changes in histomorphometric values of iliac trabecular bone and serum biochemical constituents related to bone metabolism in normal beagle dogs during growth were examined. A total of 90 dogs (male; 46, female; 44) aged 3, 6, 9, 12 and 24 months, were used. Each dog was injected with tetracycline hydrochloride and calcein for double bone labeling in order to quantitatively measure dynamic as well as static parameters in bone histomorphometry and a part of the ilium was later removed. The measurements on cancellous bone areas of undecalcified iliac sections were performed with a semiautomatic image analyzer. There were no sex significant differences in histomorphometric values except for mineralization lag time at the age of 3 months. In the static parameters, bone volume and mean trabecular thickness increased from 3 to 9 months of age. Bone surface area and mean osteoid thickness increased up to 6 months. Osteoid volume and osteoid surface area decreased up to 6 months of age. As to the dynamic parameters, the mineral apposition and bone formation rates decreased from 3 to 12 months of age. Mineralization lag time increased from 3 to 9 months of age. However, high bone surface area values in both sexes and low osteoid thickness values in females were seen at the ages of 9 and 12 months. Low values of trabecular thickness in both sexes, osteoid thickness and mineralization lag time in males and mineral apposition rate in females were also noted at the age of 12 months. Serum total calcium did not show any specific tendency.(ABSTRACT TRUNCATED AT 250 WORDS)

Alkaline Phosphatase↗
PubMed1994

Nature of the fine fibrils of the basilar membrane in the cochlea.

Fine fibrils in the basilar membranes of mouse and guinea-pig cochleae were examined by transmission electron microscopy. The fibrils were 10 nm in diameter and ran straight without branching. The fibrils appeared as two parallel lines in longitudinal sections, and round or polygonal in cross-sections, displaying tubular structures with a lumen. They were similar in ultrastructural details to the elastin-associated and elastin-independent microfibrils of Low (1962) in the subcutaneous tissue. It is concluded that the fibrils in the basilar membrane are the microfibrils.

Animals↗
PubMed1994

Interleukin-5 gene expression in nasal mucosa and changes in amount of interleukin-5 in nasal lavage fluid after antigen challenge.

Eosinophils and their products are known to cause hyperreactivity and swelling of the nasal mucosa in subjects with nasal allergy. Interleukin-5 (IL-5) not only induces differentiation and proliferation of immature eosinophils but also causes mature cells to accumulate and activate. This study shows that IL-5 is actually produced in the human nasal mucosa by antigen challenge, and it further investigates the changes in the amount of IL-5 in nasal lavage fluids after antigen challenge. Expression of mRNA for IL-5 in nasal mucosa was investigated using the reverse transcription-polymerase chain reaction (RT-PCR) and Southern blot analysis. Among the 4 subjects with nasal allergy examined in this study, expression of mRNA for IL-5 was observed in 2 prior to antigen challenge; within 6 h after antigen challenge it was seen in 3 subjects. We also found that the amount of IL-5 in the nasal lavage fluids obtained consecutively after antigen challenge increased predominantly in the late phase, and that the number of eosinophils in the IL-5 positive group was significantly higher than that in the IL-5 negative group. These results strongly suggest that IL-5 contributes to the recruitment of eosinophils in the nasal mucosa of the subjects with nasal allergy.

Adolescent↗
PubMed1994

The significance of herpes viral latency in the spiral ganglia.

To better understand the pathogenesis of idiopathic sudden hearing loss (ISHL), the possibility of latent virus infection in the spiral ganglion cell was considered. Only few spiral ganglion cells showed positive viral antigen after systemic guinea pig-specific cytomegalovirus (GPCMV) inoculation indicating the absence of hearing loss but the possibility of a subsequent latent infection. By using a modern molecular biological technique we have detected the herpes simplex virus type-1 (HSV-1) DNA in human spiral ganglia. The concept of establishing viral latency in the spiral ganglion cells with periods of reactivation fits with the clinical picture seen in ISHL, even though the mechanism of reactivation still remains unclear.

Adult↗
PubMed1994

Acute measles infection in the hamster cochlea.

Measles virus has been implicated in sudden sensorineural hearing loss (SNHL) in adults as well as in children. Furthermore, sensorineural hearing loss following live measles virus vaccination has been reported. As of yet, however, there has been only few reports on human temporal bone pathology due to measles, and on experimental animal models of measles infection. This study was undertaken to examine acute measles infection in adult hamster cochlea morphologically and immunohistochemically for precise understanding of this viral infection. Atrophy of the stria vascularis, loss of the organ of Corti, "rolled-up" tectorial membrane, and cell infiltration with a positive immunofluorescent reaction primarily within the scale media indicating endolymphatic labyrinthitis were the principal findings. These results were generally consistent with previous ones on human temporal bone pathology not only due to measles but also to SNHL. We consider measles virus to be one of the possible pathogens, even if low in frequency, causing profound and irreversible hearing loss, including SNHL. Completion of measles vaccination without complication and selective or mass revaccination may be necessary to prevent such hearing loss.

Acute Disease↗
PubMed1994

[An ELISA for the detection of anti-neutrophil cytoplasmic antibodies using the cytoplasmic alpha-fraction--clinical use for the diagnosis of Wegener granulomatosis and for monitoring its activity].

Anti-neutrophil cytoplasmic antibodies (ANCA) have been reported to be a disease-specific marker for Wegener's granulomatosis (WG). In the present study we developed an enzyme-linked immunosorbent assay (ELISA) for detecting and quantifying ANCA. The cytoplasmic alpha-fraction of neutrophils obtained from healthy human donors was used as an antigen. The alpha-fraction was purified from supernatants of homogenized neutrophils by sucrose gradient centrifugation. Peroxidase conjugated rabbit anti-human IgG was used as a secondary antibody. Diluted sera from 13 patients with WG, 15 with Sjögren syndrome, 1 with polymorphic reticulosis, 3 with relapsing polychondritis, 4 with other collagen diseases, 4 with sinusitis and 18 healthy donors were examined. It was concluded that this ELISA was sufficiently specific and sensitive for WG, and the ELISA units correlated individually with the ANCA titers as determined by an indirect immunofluorescence technique. This ELISA provides precise ANCA quantitation and will be useful for the diagnosis of WG and for monitoring its activity.

Antibodies, Antineutrophil Cytoplasmic↗
PubMed1994

[Four cases of olfactory neuroblastoma treated with craniofacial surgery].

We report 4 cases of olfactory neuroblastoma with anterior cranial fossa extension treated by craniofacial surgery. Three patients have been alive and well for 4 years, 1 year and 11 months after the initial treatment without major surgical complications but one patient died of local recurrence 11 months after treatment. Multidisciplinary surgery for olfactory neuroblastoma with intracranial extension permits radical tumor excision and reconstruction of the anterior skull base. This one-stage procedure combining neurosurgery and plastic surgery with pre or post-operative radiotherapy is considered to be essential for eradicating this tumor.

Adult↗
PubMed1994

[A case of coronary artery bypass grafting with coronary-coronary bypass for familial hypercholesterolemia].

Coronary artery bypass grafting in a 68-year-old woman with familial hypercholesterolemia and severe calcification of the ascending aorta was successfully performed. The left internal thoracic artery bypassed the left anterior descending artery, the right gastroepiploic artery bypassed the left circumflex artery and the saphenous vein graft bypassed the right coronary artery, the proximal anastomosis was based on segment 1 and the distal anastomosis was on segment 3 of the right coronary artery (coronary-coronary bypass). The operation was performed with aortic no touch technique which consisted of fibrillatory arrest without aortic cross-clamping, and femoral artery perfusion. The post operative angiogram revealed patency of all graft, and she discharged at 20th post operative day. Coronary-coronary bypass was took into consideration in a patient with severe calcification of the ascending aorta and without suitable in situ arterial graft.

Abdominal Muscles↗
PubMed1994

[Coronary artery bypass grafting for active aortitis syndrome with bilateral coronary ostial stenosis].

Coronary artery bypass grafting was performed on a 31-year-old female for treatment of active aortitis syndrome with unstable angina. Preoperative coronary angiography revealed ostial stenosis of coronary arteries. The ascending aorta was intensely inflamed. In the proximal anastomosis, the ascending aorta was sutured with an autogenous pericardial patch and anastomosed with the saphenous vein (SV) to be jointed to left anterior descending (LAD). At the same time, gastroepiploic artery (GEA) was connected to LAD by taking into account a degenerative change in remote stage. Right coronary artery was anastomosed with right internal thoracic artery (RITA). The postoperative course was satisfactory. On graft angiography SV and RITA were adequately patent, but GEA was unsatisfactorily patent because of its competition with SV for patency. This surgical procedure seemed to be an option to be indicated for a patient with unstable angina at an active inflammatory stage.

Adult↗
PubMed1994

Electron microscopic observation of pseudopodia from choriocapillary endothelium.

The choriocapillary endothelial cells project pseudopodia-like processes (pseudopodia) through defects in the basement membrane in eyes without any insult or new vessel formation. The ultrastructure of these pseudopodia was observed by transmission and scanning electron microscopy. The pseudopodia contained microfilaments, ribosome-like organella, and/or endoplasmic reticulum-like organella; about half of the pseudopodia contained bundles of microfilaments, and 10% of these contained cytoplasmic organella. The frequency of pseudopodia was not correlated with age, sex, racial difference, location in ocular fundus, or age-related changes in Bruch's membrane. The results of this study did not reveal a relationship between pseudopodia and subretinal new vessel formation. Pseudopodia oriented toward the retinal pigment epithelium (RPE) were significantly more frequent than those oriented toward the choroid or projecting from the lateral side of the choriocapillaris, which suggests a close relationship between the pseudopodia and the function of the RPE.

Adolescent↗