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Biomedical subjects

Y Aikawa

Publications and source records attributed to Y Aikawa.

At least 55 records · Page 3Linked to original sources
PubMed1991

Solubilization of steviolbioside and steviolmonoside with gamma-cyclodextrin and its application to selective syntheses of better sweet glycosides from stevioside and rubusoside.

1,4-alpha-Glucosylation at the 13-O-glycosyl moiety of stevioside (S) and rubusoside (RU) results in a significant increase of sweetness. Saponification of the 19-COO-beta-glucosyl linkage of S and RU yielded steviolbioside (SB) (= 13-O-beta-sophorosyl-steviol) and steviolmonoside (SM) (= 13-O-beta-glucosyl-steviol), respectively, both of which are poorly soluble in an acetate buffer. It was found that the solubilities of SM and SB in the buffer solution were remarkably increased in the presence of gamma-cyclodextrin (gamma-CD). SB was solubilized in the buffer solution with the aid of gamma-CD, and the solution was subjected to 1,4-alpha-transglucosylation by using a cyclodextrin glucanotransferase-starch system to give a mixture of products which were glucosylated at the 13-O-glycosyl moiety. This mixture was acetylated, and the acetate was subjected to chemical beta-glucosylation of 19-COOH followed by deacetylation to afford compounds which have superior sweetness to S. In the same way, derivatives with superior sweetness were selectively prepared from RU through SM.

Cyclodextrins↗
PubMed1991

Further study on the 1,4-alpha-transglucosylation of rubusoside, a sweet steviol-bisglucoside from Rubus suavissimus.

Rubusoside (the beta-D-glucosyl ester of 13-O-beta-D-glucosyl-steviol), which is the major sweet principle of leaves of Rubus suavissimus S. Lee, was subjected to 1,4-alpha-transglucosylation by the cyclodextringlucanotransferase-starch system (the CGTase system). The tri- and tetra-glucosylated products were isolated together with the mono- and di-glucosylated products, which had already been isolated. A prominent increase in intensity of the sweetness was observed for the compounds which were di- and tri-glucosylated at the 13-O-glucosyl moiety. This result further substantiated the structure-sweetness relationship for 1,4-alpha-glucosylated compounds of steviol-glycosides reported previously. For protection of the 19-COO-glucosyl moiety against glucosylation by the CGTase system, the 4-hydroxyl group of the 19-COO-glucosyl moiety was beta-galactosylated by the beta-galactosidase-lactose system. This galactosylated compound was subjected to a regio-selective glucosylation of the 13-O-glucosyl moiety by the CGTase system, which was followed by enzymic elimination of the galactosyl group to furnish an exclusive preparation of the improved sweeteners just mentioned.

Carbohydrate Sequence↗
PubMed1990

Effect of glycyrrhizin on pain and HLA-DR antigen expression on CD8-positive cells in peripheral blood of herpes zoster patients in comparison with other antiviral agents.

Glycyrrhizin (GL) is a saponin widely used as an anti-inflammatory agent. Pain intensity and HLA-DR antigen expression on CD8+ cells were assessed during and after treatment with GL. Other agents such as acyclovir, gamma-globulin and interferon beta were also administered for comparison. Pain resolved most rapidly among those treated with acyclovir followed by those treated with GL. Pain resolution correlated with the regression of HLA-DR+ in CD8+ subpopulations in peripheral blood. GL is suggested to be an alternative or additive antiviral agent to herpes zoster.

Acyclovir↗
PubMed1990

[Topical psoralen photochemotherapy (PUVA therapy) for severe atopic dermatitis (I): An analysis of correlation between effectiveness of PUVA therapy and clinical parameters].

Twenty-five patients with severe atopic dermatitis (AD) were subjected to PUVA therapy (topical 8-MOP application plus UVA irradiation). Excellent resolution was achieved in 18 cases (72%). Complete remission lasting 6.3 months in average was gained. In addition, the correlation between effectiveness of PUVA therapy and clinical parameters was statistically analyzed. As a result, an effectiveness of PUVA on AD was well correlated with sex (female), lower minimal phototoxic dose, higher severity and higher blood eosinophil counts. On the other hand, such correlation with the effectiveness was little in serum IgE levels, IgE.RAST scores to the house dust antigens and total irradiation doses.

Adolescent↗
PubMed1989

A case of acute tubulointerstitial nephritis and uveitis syndrome with a dramatic response to corticosteroid therapy.

A 23-year-old female with acute renal failure associated with acute tubulointerstitial nephritis and uveitis is reported. Renal tubular acidosis and inflammatory reactions consisting of markedly increased erythrocyte sedimentation rate and high serum immunoglobulin levels were seen on admission. Light microscopy revealed infiltration of mononuclear cells in the interstitium. Immunofluorescence of renal tissues was negative in staining for immunoglobulins, fibrinogen, and complement components. Bone marrow specimens did not show any granulomatous lesions. The etiology of this tubulointerstitial nephritis and uveitis syndrome was not clear. Immunological evaluation showed a slight decrease of the OKT4/OKT8 ratio in the peripheral blood. OKT8- and OKM1-positive cells had infiltrated diffusely into the renal interstitium. Acute tubulointerstitial nephritis and uveitis responded dramatically to steroid therapy. It was suggested that immunological factors might correlate with the onset and/or development of this syndrome. It is indicated that high-dose steroid therapy might be useful for patients with acute interstitial nephritis and uveitis.

Adult↗
PubMed1989

Partial purification of gelatinases and effect of anti-inflammatory drugs on the tumor necrosis factor-stimulated production of active gelatinase by granulation tissue in culture.

Gelatinases produced by granulation tissue in culture were separated into two fractions when the conditioned medium was chromatographed on diethylaminoethyl-Sephacel; one contained latent and active gelatinases with molecular weight of about 74 kDa (low-Mr gelatinase), and the other contained an active gelatinase with molecular weight of about 112 kDa (high-Mr gelatinase) as estimated by gel filtration on Sephadex G-150. The former was unbound and the latter was bound to Zn-chelating Sepharose. Both low- and high-Mr gelatinases, however, occurred in mainly two bands corresponding to molecular weights of 64 and 57 kDa on sodium dodecyl sulfate-substrate polyacrylamide gel electrophoresis. Recombinant human tumor necrosis factor-alpha (TNF) markedly enhanced the production of gelatinases, especially high-Mr active gelatinase. Dexamethasone and hydrocortisone strongly suppressed TNF-mediated production of high-Mr active gelatinase, whereas indomethacin, piroxicam and mepacrine had no effect. The results suggest that steroidal anti-inflammatory drugs suppress a rapid collagen breakdown in granulation tissue through their inhibitory actions--one of which is the suppression of active gelatinase production enhanced by cytokines including TNF.

Animals↗
PubMed1989

[HLA-DR antigen expression on peripheral T cell subsets in pityriasis rosea Gibert, herpes zoster, and psoriasis].

Using 2 color fluorescein activated cytometric analysis, HLA-DR antigen expression in T cell subsets was studied in pityriasis rosea (PR) and compared to the results from herpes zoster (HZ) of viral origin and psoriasis (Ps). In HZ and PR, HLA-DR was significantly expressed on the T cell surface (Leu-4+ cells). Among the T cell subsets, HLA-DR antigen was predominantly expressed on suppressor/cytotoxic cells (Leu-2a+) in HZ. In contrast, it was predominantly expressed on helper cells (Leu-3a+) in PR. However, activated T cell antigen (Tac) was not significantly expressed on T cells (Leu-4+) in either HZ or in PR. This HLA-DR antigen expression of T cell subsets was depressed to the normal level in the recovery phases of HZ and PR.

HLA-DR Antigens↗
PubMed1987

Tumor necrosis factor stimulates gelatinase and collagenase production by granulation tissue in culture.

Tumor necrosis factor (TNF, 2.6 X 10(-11)-10(-9) M) caused an increase in the production of active gelatinase and latent collagenase by granulation tissue in culture. As determined by SDS-substrate polyacrylamide gel electrophoresis, granulation tissue produced mainly two species of gelatinase with molecular weights of 64 kDa and 57 kDa, and an additional 80-kDa gelatinase was produced by TNF treatment. The results suggest that TNF may play a role in a rapid collagen turnover in the carrageenin-induced granulation tissue in rats.

Animals↗
PubMed1987

Kinetic characteristics and binding process of substrate analogs to the adenosine deaminase in the marine mussel, Mytilus edulis.

1. The purified mussel enzyme deaminated several adenosine analogs with different Km and relative Vmax values. Affinity for adenine was similar to that for adenosine but the deamination rate was extremely slow. 2. Purine riboside was competitive, coformycin was a tight, slow binding inhibitor, and inhibition by both these compounds was pH-dependent. 3. Inosine, hypoxanthine, guanosine and 6-mercapto-purine riboside were slightly inhibitory. 4. The results suggested that initial binding of the substrate was guided by the adenine moiety followed by a stereospecific steering due to a ribose-dependent distortion in the complex to facilitate nucleophilic attack at C-6.

Adenosine↗
PubMed1987

Affinity difference of adenosine deaminases for the purine riboside-epoxyactivated Sepharose 6B column.

The small-size adenosine deaminase (Mr = 35,000 and 43,000) in calf intestinal mucosa, frog liver and scallop adductor muscle and the large-size deaminase (Mr = 100,000) in frog liver probably formed by adding a conversion protein to the small enzyme, were tightly bound to the purine riboside affinity column. Binding of the other large-size enzymes (Mr = 140,000) in the midgut gland of scallop and mussel to the column was not successful. It seems that the binding difference does not depend on a change in affinity between active site and ligand but rather on the stereospecific positioning of active site in the enzyme molecules.

Adenosine Deaminase↗
PubMed1987

[A case of superior sagittal thrombosis secondary to hyperlipidemia].

A 42-year-old man was admitted to the Saiseikai Fukuoka General Hospital on March 22, 1985 with complaints of nausea, vomiting and headache which had continued for twelve days. On physical examinations, multiple subcutaneous nodules were noted in the chest, abdomen and extremities with dilated veins in the chest wall. Furthermore, the discoloration of the skin attributable to the venous occlusion was noted in the left foot. Neurological examinations failed to reveal any abnormalities except for moderate choked disc in bilateral ocular fundi. Spinal puncture revealed CSF pressure as high as 350 mmH2O with slight increase in cell numbers. CT demonstrated small intracerebral hematomas bilaterally in occipital lobes with evidence of "empty delta" sign in the superior sagittal sinus. On angiographical findings, the superior sagittal sinus was not demonstrated in venous phase and the blood was drained mainly through the paravertebral plexus and the pterygoid plexus without any abnormalities in arterial and capillary phases. Serological examination revealed a hypercoagulability and hyperlipidemia especially in LDL (Low Density Lipoprotein) and VLDL (Very Low Density Lipoprotein). On etiological considerations, all of these abnormalities seemed to be derived from the hyperlipidemia. Furthermore, multiple symmetrical lipomatosis was defined as a "lipoprotein storage disease" in which laboratory examinations revealed hyperlipidemia especially in LDL and in some subfraction of HDL. Although not a typical case, there must be some possibilities that the lipomatosis of this case is secondary to disorder of lipid metabolisms. In conclusion, all of various pathological conditions observed in this case were considered to be due to the disorder of lipid metabolism.

Adult↗
PubMed1987

[A case of bilateral absence of internal carotid with cerebral aneurysm].

A 52-year-old woman was referred to the Department of Neurosurgery, Saiseikai Fukuoka General Hospital because of the abnormal findings on CT from a private hospital. She had previously had two attacks of severe headache. In May 1985, she noted severe headache with vomiting and was transported to a nearby hospital. She was hospitalized there until CT was performed. On admission, she was clear in consciousness and complained of headache of moderate degree. Neurological examination was normal except for mild nuchal rigidity. A standard series of roentgenograms of the skull revealed a round calcified area in the supraclinoidal region. CT revealed a calcified lesion which must be a vessel in the chiasma cistern just adjacent to the basilar artery which was relatively larger than normal. Furthermore, no carotid canal was visible in the bilateral petrous bone by means of bony algorythum. Selective internal carotid angiographies were attempted. There was no evidence of an internal carotid artery on either sides. Furthermore,the ophthalmic arteries were fed via external carotid systems. A vertebral angiography demonstrated bilateral hypertrophy of the vertebral artery with an aneurysmal shadow in the left P1 of the posterior cerebral artery. The supratentorial circulation was maintained via the right posterior communicating artery in the right middle cerebral artery and the bilateral anterior cerebral arteries. On the other hand, the circulation of the left middle cerebral artery was maintained by the retrograde filling from the right anterior and posterior cerebral arteries. Operation was performed by left sylvian approach followed by subtemporal approach.(ABSTRACT TRUNCATED AT 250 WORDS)

Carotid Artery, Internal↗