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Biomedical subjects

Y Egawa

Publications and source records attributed to Y Egawa.

At least 19 recordsLinked to original sources
PubMed2005

Preparation of molecularly imprinted cyclodextrin microspheres.

Molecularly imprinted cyclodextrins (MI-CDs) are prepared by cross-linking CDs in the presence of a template molecule. The binding ability of MI-CDs to the template molecule is specific; therefore, MI-CDs will prove to be useful materials. In this study, we prepared microspheres of MI-CDs (MSs-MI-CD) in a dimethylsulfoxide/poly(dimethylsiloxane) (PDMS) emulsion, using cholesterol as the template molecule. MSs-MI-CD were prepared under various conditions and were evaluated with respect to their morphology, size, and binding ability. MSs-MI-CD prepared at 65 degrees C were in an aggregated form; however, we could prepare separated and uniform MSs-MI-CD at 95 degrees C. The viscosity of PDMS influenced the size of MSs-MI-CD. The mean particle diameters of MSs-MI-CD prepared with 50 and 1000 mm(2)/s PDMS were 146 and 43 microm, respectively. The binding ability of MSs-MI-CD to cholesterol was higher than that of non-imprinted microspheres. Cholesterol imprinting also promoted the binding ability to other steroids; however, the increase in binding ability was most remarkable in the case of cholesterol, suggesting that we successfully introduced the cholesterol-specific binding ability into MSs-MI-CD. The novel MSs-MI-CD preparation method is useful and simple, and it will provide opportunities for further studies on the specific binding ability of MI-CDs.

Cholesterol↗
PubMed2003

Localization of calcium in the pericarp cells of tomato fruits during the development of blossom-end rot.

Blossom-end rot (BER) of tomato ( Lycopersicon esculentum) fruits is considered to be a physiological disorder caused by calcium deficiency. We attempted to clarify the localization of calcium in the pericarp cells and the ultrastructural changes during the development of BER. Calcium precipitates were observed as electron-dense deposits by an antimonate precipitation method. Some calcium precipitates were localized in the cytosol, nucleus, plastids, and vacuoles at an early developmental stage of normal fruits. Calcium precipitates were increased markedly on the plasma membrane during the rapid-fruit-growth stage compared with their level at the early stage. Cell collapse occurred in the water-soaked region at the rapid-fruit-growth stage in BER fruits. There were no visible calcium precipitates on the traces of plasma membrane near the cell wall of the collapsed cells. The amount of calcium precipitates on plasma membranes near collapsed cells was smaller than that in the cells of normal fruits and normal parts of BER fruits, and the amount on cells near collapsed cells was small. The amount of calcium precipitates on the plasma membranes increased as the distance from collapsed cells increased. On the other hand, calcium precipitates were visible normally in the cytosol, organelles, and vacuoles and even traces of them in collapsed cells. The distribution pattern of the calcium precipitates on the plasma membrane was thus considerably different between normal and BER fruits. On the basis of these observations, we concluded that calcium deficiency in plasma membranes caused cell collapses in BER tomato fruits.

Calcium↗
PubMed2000

Effects of 1-methyl-3-propyl-7-butylxanthine (MPBX) on idarubicin-induced antitumor activity and bone marrow suppression.

The effects of 1-methyl-3-propyl-7-butylxanthine (MPBX), a xanthine derivative, on idarubicin (IDA)-induced antitumor activity against P388 leukemia cells (P388) and bone marrow suppression were examined. In P388 tumor-bearing mice, the combination of MPBX with IDA increased the antitumor activity of IDA. The IDA concentration in the tumors in the MPBX combination group increased by 2.0-fold compared to the level in the IDA-alone group. On the other hand, as regards IDA-induced bone marrow suppression, the combination of MPBX with IDA reduced the decrease in the bone marrow cell number by 30% compared to that in the IDA-alone group. In addition, the IDA concentration in the bone marrow cells was decreased by the combination of MPBX with IDA. An in vitro experiment showed that MPBX facilitated IDA influx and suppressed IDA efflux in P388 cells. In conclusion, the combination of MPBX with IDA increased the antitumor activity and decreased the bone marrow suppression. Therefore, we expect that the combination of MPBX with IDA will be useful for leukemia chemotherapy.

Animals↗
PubMed1998

[Clinical efficacy of MRCP for diagnosis of patients with pancreatic neoplasm].

We examined the usefulness of MRCP in pancreatic cancer compared with ERCP. Moreover, it examined in the same way in focal pancreatitis, too. We compare three findings of 1) main pancreatic duct, 2) branches of the stricture part, 3) side of tail main pancreatic duct about ERCP and MRCP. As for the branches of the stricture part, MRCP was poor compared with ERCP but as for the property of the side of the tail main pancreatic duct, MRCP excelled. The study of mass forming chronic pancreatitis was a similar result and was not the one, which excels ERCP in case of qualitative diagnosis. However, we thought that it was not invasively, suitable behind the digestive operation and digestive passage fault, in case of elapse observation and moreover that MRCP is suitable for pick up the pancreatic cancer in our clinic.

Adenocarcinoma↗
PubMed1997

The efficiency of antioxidants delivered by liposomal transfer.

Phenolic antioxidants of the hydroxychroman class, alpha-tocopherol (alpha-TOC) and 2,2,5,6,7-pentamethyl-6-hydroxychroman (PMHC), and the hindered phenols 2,3-dihydro-5-hydroxy-2,2,4-trimethylnaphtho[1,2-b]furan (NFUR), 2,6-di-tert-butyl-4-methoxyphenol (DBHA), and 2,6-di-tert-butyl-4-methyl phenol (BHT), were delivered into oxidizable (ACCEPTOR) liposomes of dilinoleoylphosphatidylcholine (DLPC) or 1-palmitoyl-2-linoleoyl-phosphatidylcholine (PLPC) from saturated DONOR liposomes of dimyristoylphosphatidylcholine (DMPC) by liposomal transfer. The antioxidant activities, k(inh), by the inhibited oxygen uptake method were compared with the k(inh)s determined when the antioxidants were introduced into the liposomes by coevaporation from organic solvents. The peroxidations were initiated using either thermal initiators, water-soluble azo-bis-amidinopropane hydrochloride (ABAP), lipid-soluble azo-bis-2,4-dimethylvaleronitrile (ADVN) and di-tert-butylhyponitrite (DBHN), or the photoinitiator benzophenone. The antioxidants PMHC, NFUR, DBHA, and BHT transferred rapidly between liposomes, but several hours of incubation were needed to transfer alpha-TOC. The average k(inh)s in liposomes, in the relative order NFUR approximately DBHA > PMHC > BHT approximately alpha-TOC, were markedly lower than known values in organic solvent. k(inh) values in liposomes appear to be controlled by effects of hydrogen bonding with water and by restricted diffusion of antioxidants, especially in the case of alpha-TOC. Product studies of the hydroperoxides formed during inhibited oxygen consumption were carried out. The cis,trans/trans,trans (c,t/t,t) product ratios of the 9- and 13-hydroperoxides formed from PLPC during inhibited peroxidation by PMHC were similar for both the coevaporated and liposomal transfer procedures. The c,t/t,t ratio for the same concentration of alpha-TOC, 1.52, compares to a value of 1.69 for PMHC at the start of the inhibition period. The higher c,t/t,t ratio observed for NFUR in DLPC, which varied between values of 7.0 at the start of the inhibition to about 1.8 after the break in the induction period, is a reflection of the increased hydrogen atom donating ability of the antioxidant plus the increased concentration of oxidizable lipid provided by DLPC.

Amidines↗
PubMed1996

Effect of beta-glucans on the nitric oxide synthesis by peritoneal macrophage in mice.

Nitric oxide (NO) is an important effector molecule on antimicrobial and antitumor effects of macrophages. (1 -> 3)-beta-D-Glucan (beta-glucan) is well known to show various immunopharmacological effects such as antimicrobial effect and antitumor effect by activating various points of host defense mechanisms. This paper deals with NO synthetic activity of peritoneal macrophage (PM) induced by beta-glucan administration in mice. The activity was determined by measuring NO concentration in PM culture by Griess reagent after 24 or 48 h in vitro culture. Administration (i.p. or i.v.) of a branched soluble (1 -> 3)-beta-D-glucan, grifolan (GRN), from Grifola frondosa enhanced NO synthesis of PM dose and time dependently. The activity was abrogated by the addition of N(G)-monomethyl-L-arginine (L-NMMA) in vitro. The most significant activity was observed at 3-7 d after the administration of GRN (250 mu g/mouse). PM from all strains of ICR, C3H/HeN, C3H/HeJ, BALB/c, BALB/c nu/nu, C57BL, and AKR mice showed significant activity by GRN administration. Among beta-glucans tested, SSG and OL-2, highly branched soluble glucans, and a particulate beta-glucan, zymosan, showed similar activity. Addition of GRN directly to in vitro RAW 264.7 or proteose peptone induced peritoneal macrophage (PP-PEC) culture could not enhance NO synthesis. However, NO synthesis of PP-PEC was enhanced in vitro by addition of GRN in the presence of interferon gamma (IFN gamma). Gene expression of IFN gamma mRNA in the liver and PEC were enhanced in GRN administered mice assessed by reverse transcriptase assisted PCR (RT-PCR) method. These facts strongly suggested that beta-glucan has capacity to enhance NO synthesis of PM in vivo through IFN gamma mediated mechanism.

Adjuvants, Immunologic↗
PubMed1995

Kinetic study of quenching reaction of singlet oxygen and scavenging reaction of free radical by squalene in n-butanol.

The rate constant of quenching of singlet oxygen (kQ) by squalene (SQ) is found to be much larger than those of the lipids in human skin surface. SQ is the first target lipid in human skin surface by oxidative stresses such as sun light exposure. kQ of SQ is similar to that of 3,5-di-t-butyl-4-hydroxytoluene (BHT). The large kQ of SQ is due to the small ionization potential. SQ consists of six 2-methyl-2-pentene units and kQ of SQ is about 6-times as large as that of 2-methyl-2-pentene. The electron donating property of methyl groups bonded to quaternary carbons of SQ is essential to the large kQ. SQ is not very susceptible to peroxidation and is stable for attacks by peroxide radicals. The chain reaction of lipid peroxidation is unlikely to be propagated with SQ in human skin surface. It is concluded that SQ functions as an efficient quencher of singlet oxygen and prevents the corresponding part of lipid peroxidation in human skin surface.

1-Butanol↗
PubMed1995

Sequence of the Rhodococcus equi gene encoding the virulence-associated 15-17-kDa antigens.

The nucleotide sequence of the Rhodococcus equi gene encoding the virulence-associated 15-17-kDa antigens, located on plasmid pREAT701, has been determined. The gene encodes a 19-kDa protein of 189 amino acids, with an Ala-rich leader signal sequence (SS). At least five SS peptidase cleavage sites were found in this region. The molecular diversity of 15-17-kDa antigens might be attributed to the multiple SS peptidase cleavage sites.

Amino Acid Sequence↗
PubMed1995

[A rare complication of catheter balloon valvuloplasty of pulmonary stenosis--a case report].

We describe a rare complication which occurred during catheter balloon valvuloplasty to the stenosis of the pulmonary artery. A 4-year-old girl with cyanosis who was diagnosed as having tetralogy of Fallot, patent foramen ovale and Down's syndrome underwent the cardiac catheralisation and angiography. Angiography showed the stenosis from outlet of right ventricle to bifurcation of the pulmonary artery. We attempted catheter balloon valvuloplasty to the stenosis of the pulmonary artery subsequently. We used the PTA catheter (NuMED INC, canada), 10 mm in diameter. The balloon was inflated twice (6 atm, 5 sec, 8 atm, 7 sec) at the bifurcation of the pulmonary artery safely. However, during third trial to inflate to 8 atm, it proved impossible to increase pressure to the desired level of 8 atm. Blood backed up in the catheter and it became impossible to deflate the balloon. We failed to remove the catheter through the left femoral vein, so we led the catheter to the right internal jugular vein with a guidewire. The catheter was successfully extracted in this way. The proximal connection between the balloon and the outer tube was broken and the balloon was compressed. To our knowledge, such as complication as this has not reported previously.

Catheterization↗
PubMed1994

New operative method for tracheal compression in congenital heart disease.

A new technique is described for repairing tracheal compression caused by ascending aorta associated with corrected transposition of the great arteries and pulmonary atresia in a 113-day-old infant. Surgical repair for the tracheal compression was accomplished by suspending the pericardium around the aortic arch to the underside of the sternum. This method seems to be useful for some patients with tracheal compression caused by the ascending aorta.

Airway Obstruction↗
PubMed1994

[Use of patch-scratch tests to determine penicillin and cephem allergies].

The drug eruptions caused by penicillins and cephems and the patch-scratch test reactions to these drugs are discussed herein. Five hundred eighty two patients were diagnosed with drug eruption as a result of patch-scratch tests, history, gurgle tests or challenge tests in the 22 years from 1971 to 1992 in our department. Of these cases 53.8% were caused by penicillins, and 29.9% by cephems. The number of cases of allergic reactions to both, especially cephems has been increasing steadily over the last 10 years. Patch-scratch tests were performed on 382 patients among 385 patients with drug eruption caused by penicillin or cephem out of the 582 patients above mentioned. Among these patients, the patch-scratch test positive rate for penicillins and cephems was 84%, suggesting that the patch-scratch test is useful for identifying penicillin and cephem allergies. Patch-scratch tests for our antibiotics series were performed on 1256 patients with drug eruption or contact dermatitis caused by some allergens, whether the allergens were penicillins or cephems, or neither, 29.5% of these showed positive reactions to penicillins and 12.7% to cephems. Among these patients, patch-scratch tests for our penicillin and cephem series were also performed on 81 patients, 88.9% of whom showed positive reactions to penicillins and 59.3% to cephems. The highest incidence of positive reactions, 77.8%, occurred with wide spectrum semisynthetic penicillins. Of this group, ampicillin had the highest incidence at 58%. In 32 cases, the allergen could be detected. As to the clinical types of these cases, maculopapular eruptions and erythroderma showed the highest incidence. Cross reactions also occurred within the same group, most being for wide spectrum semisynthetic penicillin. The optimum concentration of each allergen used in the patch-scratch tests was evaluated on the basis of the relationship between the concentration of the allergens and the results of the patch-scratch tests. The results were 20w/w% in ABPC, AMPC, SBPC, CER, CMZ, CZX and LMOX, 10 w/w% in PCG and CBPC, 5w/w% in CMD. Drug lymphocytic stimulation tests were performed in 12 cases, with 15 drugs producing positive patch-scratch test reactions. Only 3 drugs showed positive reactions, suggesting that this test is unreliable.

Cephalosporins↗
PubMed1994

[A case of thoracic aortic aneurysm associated with atypical coarctation and kinking of the aortic arch].

The aneurysm associated with atypical coarctation and kinking of the aortic arch is rare. Authors experienced such a case and performed operation using bypass technique as below. A 17-year-old male admitted to the authors' hospital to undergo operation of the enlarging thoracic aneurysm. He was observed from his childhood diagnosed as the coarctation and kinking of the aortic arch. The chest X-ray films showed a mass shadow in the left superior mediastinum. It had been also diagnosed as having a small post-stenotic dilation of aortic arch. Recently the mass on the X-ray enlarged. He was diagnosed as an aneurysm located on aortic arch using MR-imaging and aortogram. The aneurysmectomy was performed because of the possibility of the aneurysmal rupture. Under the general anesthesia, extra-anatomical bypass was made between ascending aorta and descending aorta, and another one between the bypass and left common carotid like as T-shape, because the proximal aneurysm was very near located on the origin of left common carotid. The aneurysm was excised and woven Dacron graft was implanted. The post-operative course was uneventful. This case suggests the necessity of deliberate clinical observation using roentgenography for a case of kinking of the aortic arch.

Adolescent↗
PubMed1993

Changes in plasma dopamine-beta-hydroxylase activity during the perioperative period of cardiac surgery: an index of sympathetic nerve activity.

To evaluate the usefulness of plasma dopamine-beta-hydroxylase (DBH) activity as an index of sympathetic nerve activity during cardiac operations, we examined the serial changes in plasma DBH activity, in relation to the plasma noradrenaline (NA) level and hemodynamic parameters, in patients who underwent cardiac surgery. The plasma DBH activity decreased significantly after cardiopulmonary bypass, and remained low during dopamine (DA) infusion until 72 h after the operation. However, recovery of the hemodynamic parameters, being the mean arterial pressure, heart rate and cardiac index, was seen as early as 1-3 h postoperatively. It was therefore assumed that the plasma DBH activity takes a long time to recover after an operation. The time-course changes in the plasma NA level were quite different from the changes in DBH activity, with an apparent negative correlation being observed between them. Thus, there is a possibility that exogenously administered DA, as well as increased plasma NA, might inhibit DBH activity during cardiac surgery. Moreover, since catecholamines are often administered upon completion of cardiac surgery, measurement of the plasma catecholamine level would be inappropriate for evaluating real sympathetic nerve activity. From the results of this study, it is surmised that measurement of the plasma DBH activity could be useful for estimating the intrinsic sympathetic nerve activity of patients who have undergone cardiac surgery.

Adult↗
PubMed1993

Reduction in arm swelling and changes in protein components of lymphedema fluid after intraarterial injection of autologous lymphocytes.

The intraarterial arm injection of freshly isolated autologous lymphocytes to a patient with upper extremity secondary lymphedema brought about a rapid and remarkable reduction in arm swelling. The protein components in the edema fluid were analyzed by two-dimensional electrophoresis before and after lymphocyte injection. We observed the appearance of a novel protein spot, with an isoelectric point of 6.5, in an electropherogram as early as 30 minutes after the lymphocyte injection. Immunoblotting using antibody against human total serum proteins suggested that the novel protein was not derived from the serum. Because incubation in vitro of the lymphedema fluid with the isolated lymphocytes produced a new protein spot, corresponding to the novel protein observed in vivo, we suspect that the novel protein originated from limited hydrolysis of a unique protein present in the arm edema fluid. Significance of the novel protein and the role of limited proteolysis after lymphocyte injection in the management of lymphedema are examined.

Electrophoresis, Gel, Two-Dimensional↗
PubMed1993

[A case report of cor triatriatum benefit of MRI for preoperative diagnosis and surgical method].

Cor triatriatum is uncommon in all congenital heart diseases. It is a malformation resulting in a separation of the left atrium or right atrium into two chambers due to a congenitally abnormal diaphragm. We wish to present a case of cor triatriatum in which MRI was found most useful for preoperative diagnosis and surgical procedure. A 2-year-old girl was transferred to us for severe pulmonary congestion as shown on chest X-ray. Echocardiography showed abnormal diaphragm in the left atrium. MRI demonstrated clearly the relationship between left pulmonary vein and the abnormal diaphragm. Therefore we should preoperatively determine type I A according to the Lucas and Schmidt's classification. Cardiac catheterization showed moderate pulmonary hypertension and confirmed cor triatriatum. The resection of the abnormal diaphragm was performed under extracorporeal circulation with moderate hypothermia. The postoperative course was uneventful. MRI is a very useful non-invasive technique in making a diagnosis and in choosing the appropriate surgical procedure for cor triatriatum.

Child, Preschool↗
PubMed1993

[A case of tetralogy of Fallot associated with isolation of a subclavian artery and partial DiGeorge syndrome].

A month old girl was referred to our hospital for heart murmur and congestive heart failure. After the UCG and angiography, clinical diagnosis was tetralogy of Fallot, right aortic arch, isolation of left subclavian artery (Victorica type I), and a patent ductus arteriosus that originated from left subclavian artery. The direction of blood flow in the patent ductus arteriosus was from a subclavian artery to pulmonary artery, so she was in the condition of pulmonary over flow and appeared congestive heart failure, although she associated with tetralogy of Fallot. With intraoperative and postoperative examinations, we diagnosed the association of partial DiGeorge syndrome. Isolation of subclavian artery is uncommon, but this anomaly was classified by Victorica. Embryology of this anomaly was explained with hypothesis of double arch system. We had seen no reports of DiGeorge syndrome associated with isolation of a subclavian artery. But DiGeorge Syndrome is hypoplasia of branchiogenic organs, and subclavian arteries is differentiated from brachial arteries. So we supposed that this two lesions have the possibility of combination.

Aorta, Thoracic↗
PubMed1993

[A case of pseudoaneurysm of the thoracic aorta with Behçet's disease].

A 54-year-old female with incomplete type of Behçet's disease was operated on because of impending rupture of the thoracic aneurysm. There was a saccular pseudoaneurysm below the left subclavian artery, and a punched out lesion of the aorta was recognized. The defect of the aortic wall was closed with a PTFE patch. Before and after the operation, we have given prednisolone. The postoperative course was uneventful. Two years later, there was no recurrence of pseudoaneurysm near the PTFE patch. In many reports, aneurysms of Behçet's disease are saccular pseudoaneurysms, and have high incidence of complications about anastomosis postoperatively. We need a further follow-up about this patient.

Aortic Aneurysm, Thoracic↗