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T Sugawara

Publications and source records attributed to T Sugawara.

At least 19 recordsLinked to original sources
PubMed1992

Contribution of the 6-120 disulfide bond of alpha-lactalbumin to the stabilities of its native and molten globule states.

The unfolding and refolding of a derivative of alpha-lactalbumin, in which the disulfide bond between Cys6 and Cys120 is selectively reduced and S-carboxymethylated, are investigated by equilibrium and kinetic circular dichroism measurements. The native conformation of this derivative is known to be essentially identical to that of intact alpha-lactalbumin. The equilibrium unfolding of the derivative involves a stable intermediate, which is also similar to the molten globule state of the disulfide intact protein. The results of stopped-flow circular dichroism experiments show that the same intermediate is formed rapidly as a transient intermediate in kinetic refolding. The conformational stabilities for the native and intermediate states have been estimated and compared with the stabilities for the corresponding states of intact alpha-lactalbumin. The stabilization of the native state by the disulfide has been interpreted in terms of a decrease in chain entropy in the unfolded state and elimination of the strain imposed on the disulfide bond in the native state. The molten globule state is also stabilized by the disulfide bond, although the degree of stabilization of the molten globule state is smaller than of the native state. The results suggest that, in the molten globule state, some ordered structures are present within the loop moiety formed by the 6-120 disulfide.

Animals↗
PubMed1992

Vitamin E: inhibition of retinol-induced hemolysis and membrane-stabilizing behavior.

For the elucidation of the mechanism of membrane stabilization by vitamin E, the effects of alpha-tocopherol and its model compounds on either retinol-induced hemolysis of rabbit erythrocytes or the permeability and fluidity of liposomal membranes have been studied. Retinol-induced rabbit erythrocyte hemolysis has been found not to be caused by the oxidative disruption of erythrocyte membrane lipids initiated by retinol oxidation, but rather to arise from physical damage of the membrane micelle induced by penetration of retinol molecules. In suppressing hemolysis, alpha-tocopherol was more effective than other naturally occurring tocopherols. alpha-Tocopheryl acetate, nicotinate, and 6-deoxy-alpha-tocopherol were more effective than alpha-tocopherol itself. The inhibitory effects of alpha-tocopherol model compounds having side chains with at least two isoprene units or a long straight chain instead of the isoprenoid side chain were similar to those of alpha-tocopherol. These data suggest that for protection of membranes against retinol-induced damage, the hydroxyl group of alpha-tocopherol is not critical, but rather the chroman ring, three methyl groups on the aromatic ring, and the long side chain are necessary. To verify the mechanism of the inhibitory effect on hemolysis, not only the effect of vitamin E and its model compounds on the membrane permeability and fluidity, but also the mobility of alpha-tocopherol molecule in membranes has been investigated using bilayer liposomes as the model membranes. Addition of alpha-tocopherol to membranes produced a greater decrease in the permeability and fluidity of rat liver phosphatidylcholine liposomes compared with egg yolk phosphatidylcholine liposomes. In dipalmitoylphosphatidylcholine liposomes, however, alpha-tocopherol was less effective, that is, the more unsaturated the lipids, the more they interact with alpha-tocopherol. 2,2,5,7,8-Pentamethyl-6-chromanol with no isoprenoid side chain and phytol without the chromanol moiety had no effect. The measurement of 13C NMR relaxation times revealed that the mobility of methyl groups on the aromatic ring of alpha-tocopherol in membranes is significantly restricted. In contrast, the methyl groups at positions 4'a and 8'a on the isoprenoid side chain have high degrees of motional freedom in the lipid core of membranes. Furthermore, it was found that alpha-tocopherol in membranes interacts with chromate ions added as potassium chromate outside the membranes, resulting in an increase in membrane fluidity. These results are compatible with those of the inhibitory effect on retinol-induced erythrocyte hemolysis. On the basis of the results obtained here, a possible mechanism for membrane stabilization by vitamin E is proposed.

Animals↗
PubMed1992

Time course of dorsal root axon regeneration into transplants of fetal spinal cord: I. A light microscopic study.

Cut dorsal root axons regenerate into intraspinal transplants of fetal spinal cord and establish synaptic connections there. The aims of the present study were to describe the progression of dorsal root growth within the transplants and the maturation of transplant morphology and to determine whether the regenerated dorsal root axons persist within the transplants or eventually withdraw. Embryonic (E) day 14 spinal cord was grafted into the lumbar enlargement of adult Sprague-Dawley rats, and the L4 or L5 dorsal root was cut and juxtaposed to the transplants. The morphology of the transplants was examined from 1 day to over 1 year after surgery, and the regenerated dorsal roots were labeled with immunohistochemical methods to study the subset that contains calcitonin gene-related peptide (CGRP). Embryonic spinal cord transplants survived and grew within the host spinal cord in over 90% of the animals. Transplant volume increased and the morphology of the transplants matured over the first 12 weeks and then did not change for 48-60 weeks. During the first week the transplants were composed of dissociated neurons, glia, and hematogenous cells with considerable extracellular space between them. Subsequently, the grafted neurons became densely aggregated, and non-neuronal elements such as inflammatory cells and myelin debris disappeared. CGRP-immunoreactive dorsal roots began to regenerate into the transplants within 24 hours, formed dense bundles by 4 days, and were still present at 60 weeks, the longest survival period examined. Myelination of axons within transplants began at 2 weeks. Quantitative analysis showed that the area of the transplants occupied by CGRP-labeled axons and the distribution area of the labeled axons within the transplants increased until 12 weeks and persisted unchanged for over 48 weeks. These results indicate that regenerated dorsal root axons are permanently maintained within transplants of embryonic spinal cord and suggest that the transplants can contribute to the permanent restoration of damaged intraspinal neural circuits.

Animals↗
PubMed1992

Pharmacological aspects of arthritis induced by a muramyl dipeptide analogue in rats.

Fourteen consecutive daily subcutaneous injections of 4 mg/kg of the muramyl dipeptide analogue MDP-Lys(L18) into rats caused arthritis characterized by swelling of the tarsal joint, increases in lymphocytes and monocytes in the peripheral blood, and elevated serum immunoglobulin G (IgG). The present study was performed to evaluate the effects of indomethacin, phenylbutazone, dexamethasone, D-penicillamine, aurothioglucose, cyclophosphamide and cyclosporin A on this arthritis. Administration of indomethacin, phenylbutazone or dexamethasone inhibited the development of the tarsal joint swelling, suggesting that prostaglandins may be involved in the pathogenesis of the arthritis. Cyclophosphamide reduced the arthritis, together with decreases in the lymphocyte count and the serum IgG level. Cyclosporin A worsened the arthritis in a dose-dependent manner and increased the neutrophil count without raising the serum IgG level, but inhibited the induction of adjuvant arthritis in rats with Mycobacterium bacilli. MDP-Lys(L18) may therefore induce arthritis differing in mechanism from adjuvant arthritis.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1992

Synthesis of omega-(methoxycarbonyl)alkyl and 9-(methoxycarbonyl)-3,6-dioxanonyl glycopyranosides for the preparation of carbohydrate-protein conjugates.

omega-(Methoxycarbonyl)alkyl glycopyranosides of D-mannose having C4, C7, C9, C12, and C15 carbon chains, L-fucose and 2-acetamido-2-deoxy-D-mannose having C7 and C9 carbon chains, D-xylose and 2-acetamido-2-deoxy-L-fucose having a C9 carbon chain, and 9-(methoxycarbonyl)-3,6-dioxanonyl glycopyranosides of D-mannose, 2-acetamido-2-deoxy-D-mannose, and L-fucose were synthesized as intermediates for coupling to human serum albumin in order to examine the effect of chain length and hydrophobicity of the spacer arm on the binding specificity of lectins. 8-(Methoxycarbonyl)octyl glycosides of beta-D-Man-(1----2)-alpha-D-Man, alpha-D-Man-(1----2)-alpha-D-Man, alpha-D-ManNAc-(1----2)-alpha-D-Man, beta-D-GlcNAc-(1----2)-alpha-D-Man, and their 6-O-positional isomers, beta-D-Man-(1----6)-alpha-D-Man, alpha-D-Man-(1----6)-alpha-D-Man, alpha-D-ManNAc-(1----6)-alpha-D-Man, and beta-D-GlcNAc-(1----6)-alpha-D-Man, were also synthesized.

Carbohydrate Sequence↗
PubMed1992

Arthritis and hematological changes induced by an analogue of muramyl dipeptide in rats.

We examined changes of blood cell counts and development of arthritis induced by daily subcutaneous injections of MDP-Lys(L18), an analogue of muramyl dipeptide (MDP), in rats. The numbers of neutrophils markedly increased in the peripheral blood 4 hr after the 1st, 7th, and 14th administrations of MDP-Lys(L18), but they recovered to the control levels within 24 hr. Monocyte and lymphocyte counts increased after the 7th and 14th administrations, respectively, although both decreased after the 1st dosing. Serum inflammatory markers, such as albumin, globulin, mucoprotein, sialic acid, and iron, showed marked changes after the 1st administration. Histopathologically, the synovial membrane of the tarsal joint showed a multilayer arrangement of synoviocytes with vesicular cytoplasms and infiltration of neutrophils from 6 hr after the 1st administration of the drug. The acute synovitis was gradually enhanced until 24 hr later. The synovitis was greatly decreased in degree after the 3rd administration, but increased again later. After the 7th and 14th administrations, mononuclear cells and lymphocytes, respectively, infiltrated the synovial membrane, in a manner corresponding to the hematological findings. However, exudative changes and neutrophilic infiltration were still observed after the 14th drug administration, and the synovitis was repaired after a 7-day recovery period.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1992

IgE levels in faecal extracts of patients with food allergy.

IgE levels in faecal extracts (Copro-IgE levels) were investigated in food allergy (FA) patients before and after the challenge test administration of food allergens. IgE levels were measured by time-resolved fluoroimmunometric assay. In addition, the effects of administration of oral sodium cromoglycate (SCG) on the Copro-IgE levels were studied. Copro-IgE levels in patients with FA, who were placed on an elimination diet, did not differ from those of healthy children. After a challenge test immediate symptoms of urticaria and wheezing were observed in all FA patients. Copro-IgE levels in each patient increased markedly within 24 h of the challenge test. Moreover, FA patients treated orally with SCG showed neither the increase in Copro-IgE levels nor any remarkable symptoms after the challenge. Our results suggest that the increased Copro-IgE levels may be a specific consequence of the local immune response to food allergen stimulation in the gut mucosa.

Allergens↗
PubMed1992

48, XXYY syndrome associated with ethylenediaminetetraacetic acid (EDTA)-dependent pseudothrombocytopenia.

A 56-yr-old man with hypogonadism, gynecomastia, and mental retardation was evaluated for chromosome constitution and thrombocytopenia. Chromosomal analysis demonstrated the mosaicism of 48, XXYY and 47, XXY in the peripheral lymphocytes. Twenty out of twenty-five cells were 48, XXYY karyotype and the remaining five were 47, XXY karyotype. Thrombocytopenia was the EDTA-dependent pseudothrombocytopenia type 1 (platelet agglutination). Serological examination suggests that the platelet agglutinin belongs to IgM-kappa type. The present case exhibited both EDTA-dependent pseudothrombocytopenia and the 48, XXYY syndrome. Although this combination may have occurred purely by change, the possibility of whether or not the mosaicism of lymphocytes produces platelet agglutinin remains to be clarified.

Edetic Acid↗
PubMed1992

Serum interleukin-2 receptor and interferon-alpha levels in a patient with allergic granulomatous angiitis (Churg-Strauss).

A patient with allergic granulomatous angiitis accompanied by increases in serum interleukin-2 receptor (IL-2R) and interferon-alpha (IFN-alpha) levels is reported. Laboratory findings revealed leukocytosis with eosinophilia and increased serum IgE and IgG. The serum IL-2R and IFN-alpha were increased. The serum immune complex, interferon-beta, -gamma and complements remained at normal levels. The serum IgE, IgG, IL-2R and IFN-alpha correlated with disease activity. Immunofluorescent studies using frozen sections obtained from the dermal lesion showed no immunoglobulin or complement deposits on vascular walls. Measurements of serum IL-2R and IFN-alpha might be considered reliable serologic indicators of disease activity.

Adult↗
PubMed1992

Experimental investigation of a new liquid embolization method: enhancing effect of 25% ethanol on conjugated estrogen.

A new liquid embolization material applicable to intracranial lesions was evaluated by selective renal artery embolization in mongrel dogs. Absolute and diluted ethanol, estrogen, and estrogen in 25% ethanol (ethanol-estrogen) were injected. The embolization and side effects were investigated angiographically and histologically. Ethanol-estrogen caused similar embolization to absolute ethanol, but no direct damage to perivascular tissue, and is considered a promising embolization agent in intravascular surgery.

Animals↗
PubMed1992

Surgical excision of giant cerebellar hemispheric arteriovenous malformations following preoperative embolization. Report of two cases.

The authors present two cases of giant cerebellar hemispheric arteriovenous malformation (AVM) managed with staged preoperative embolization and surgical resection. A new embolization technique is described, combining injection of estrogen alcohol and polyvinyl acetate into AVM's by superselective catheterization of feeding arteries. Polyvinyl acetate proved to be an ideal liquid embolic material; because it polymerizes quickly and remains in a gelatinous state after injection, there was no difficulty in cutting and retracting the obliterated AVM during surgery. Intraoperative digital subtraction angiography was useful for confirming complete excision of the large and complex AVM.

Adolescent↗
PubMed1992

[Protective effect of dextromethorphan on the ischemic retinal damage in rabbit].

To investigate the effect of dextromethorphan (DEX), N-methyl-D-aspartate (NMDA) receptor antagonist, on the retinal ischemia, 0.4%DEX hydrobromide was intravenously given to rabbits before, during and after retinal ischemia. Retinal function was monitored by electroretinogram (ERG). Retinal ischemia was induced by increasing intraocular pressure to 130 mmHg for 90 or 120 min. Amplitudes of ERG.b-waves recorded after the 90 min ischemia recovered to 72.5 +/- 9.0% in the DEX group and 38.5 +/- 8.5% in the control group which was given normal saline. The maximal recovery rates of b-wave amplitudes after the 120 min ischemia were 44.0 +/- 7.9% in the DEX group and 21.0 +/- 1.3% in the control group. The recovery rates of the b-wave amplitudes in DEX group were significantly higher than in the control group (p less than 0.01). It was found that the effective dose of DEX was 0.1-0.4%.

Animals↗
PubMed1992

[Two cases of mucinous adenocarcinoma of the prostate].

We report two cases of mucinous adenocarcinoma of the prostate. A 56-year-old man underwent subcapsular prostatectomy under the diagnosis of benign prostatic hyperplasia in 1968, and was found to have mucinous adenocarcinoma of the prostate, which proved to be prostatic acid phosphatase (PAP) and prostate specific antigen (PSA) positive, and carcinoembryonic antigen (CEA) negative by immunohistochemical staining. Subsequently he received 70 Gy of irradiation to the prostate, but died in 1976, when serum PAP was elevated. Autopsy revealed metastases to the liver, lungs, bone, peritoneum, spleen, pancreas, lymph nodes, and no primary gastrointestinal adenocarcinoma. The other case was a 57-year-old man, who underwent transurethral resection (TUR) for papillary tumor located just lateral to the verumontanum in 1982. The tumor was misdiagnosed as adenomatous polyp, and was PSA and PAP negative, and CEA positive. After 3 TURs of the recurrent tumor on the prostatic urethra, he underwent prostatourethrectomy, pelvic lymphadenectomy, and cystostomy for radical cure in 1985. The specimen proved to be mucinous adenocarcinoma of the prostate. He suffered recurrence of the tumor in the retrovesical space in 1987, and died in 1990. Autopsy revealed no evidence of metastasis except the local recurrence and no primary gastrointestinal adenocarcinoma.

Adenocarcinoma, Mucinous↗
PubMed1992

[Delayed treatment with dextromethorphan can reduce ischemic retinal damage in rabbit].

Previous studies have suggested that prophylactic treatment by dextromethorphan (DEX), N-methyl-D-aspartate (NMDA) receptor antagonist can protect the retina against ischemia. To investigate the effect of DEX on the proceeding ischemic retina, 0.1% DEX hydrobromide was intravenously administered in rabbits immediately (group A), 1 hour (group B) or 2 hours (group C) after the release from ischemia induced by increasing intraocular pressure to 130 mmHg for 90 min. Normal saline was infused immediately after the release from ischemia as control rabbits. Retinal function was monitored by recording electroretinogram (ERG). Twenty four hours after the release of ischemia, the recovery rates of ERG.b-wave amplitudes in groups A, B and C were 61.3 +/- 3.3, 52.2 +/- 9.0 and 43.6 +/- 8.4% of the preischemic amplitude, respectively. The recovery rate of the group A was higher than that of the control (41.9 +/- 10.6%), while no significant differences were seen between groups B or C and the control. The results suggest that DEX can protect the retina if it is administered immediately after the release of ischemia.

Animals↗
PubMed1992

[Biochemical study on steroid sulfatase and its clinical application to the obstetrics and gynecology].

Steroid sulfatase desulfates a number of 3 beta-hydroxysteroid sulfates, converting inactive steroid hormone to the active form. I have developed an enzyme-linked immunosorbent assay (ELISA) using polyclonal antibody against the sulfatase which was purified from human placenta to measure an amount of the enzyme protein in sera of gynecologic cancer patients. By this method, it was found that the serum steroid sulfatase level is significantly elevated in patients with endometrial carcinoma (p less than 0.05) and ovarian carcinoma (p less than 0.01) as compared to that of normal women. Steroid sulfatase deficiency, X-linked ichthyosis (XLI) is an inherited skin disorder. The sulfatase gene and the enzyme protein were examined in patients with XLI. When the first and last (exon 10) exons of the sulfatase gene were amplified by PCR using patients' genomic DNA as templates, no product was detected in all six cases examined. In addition, neither mRNA of the sulfatase nor the enzyme protein was detected in a patient with XLI. These observations suggest that most Japanese XLI patients are caused by an extensive deletion of the steroid sulfatase gene.

Arylsulfatases↗