Biomedical subjects

T Murata

Publications and source records attributed to T Murata.

At least 271 records · Page 15Linked to original sources

PubMed1998

Chemo-enzymatic synthesis of galactosylmaltooligosaccharidonolactone as a substrate analogue inhibitor for mammalian alpha-amylase.

We performed chemo-enzymatic transformation of maltooligosaccharides into both end-modified oligosaccharidonolactones of potential use as substrate analogue inhibitors for mammalian alpha-amylases. Enzymatic modification of the non-reducing end glucosyl residue of the maltooligosaccharide was first performed by transglycosylation with beta-D-galactosidase from Bacillus circulans. When maltotriose and maltotetraose were the acceptors, the enzyme regioselectively synthesized 4(3)-O-beta-D-galactosyl maltotriose (LG3) and 4(4)-O-beta-D-galactosyl maltotetraose (LG4) from lactose as a donor. LG4 was further selectively hydrolyzed with a specific alpha-amylase to afford 4(2)-O-beta-D-galactosyl maltose (LG2). The anomer hydroxyl groups of LG2 and LG3 were chemically oxidized to give the corresponding lactones, 4(2)-O-beta-D-galactosyl maltobionolactone (LG2O) and 4(3)-O-beta-D-galactosyl maltotrionolactone (LG3O), respectively. LG2O and LG3O, which are competitive inhibitors for mammalian alpha-amylases, exhibited Ki values of the order of 2.8-18.0 microM, with p-nitrophenyl alpha-maltopentaoside (G5P) as the substrate. On 1H-NMR analysis, these oligosaccharidonolactones were shown to be transformed into the corresponding aldonic acid forms with time in an aqueous solution. In this case, the lactone form was essential for the occurrence of the alpha-amylase inhibitor.

Animals↗

PubMed1998

Hepatic histopathology of a vitamin A overdose in mouse liver.

The effect of vitamin A on peroxisomal catalase in liver of male ICR mice was studied electron microscopically after a single subcutaneous injection of retinyl acetate. A significant proliferation of peroxisomes in hepatocytes was observed up to 3 days after a single injection of 80,000 IU of retinyl acetate. This was followed by a significant decrease up to 21 days and increase above control levels at 60 days after the injection. Histopathological alterations, such as focal necrosis of hepatocytes in the peripheral zone of hepatic lobules, release of their membrane-bound bodies from Disse's space and the appearance of large vacuoles around the nucleus, were observed from early stages onwards. These findings indicated that alterations on lipid metabolism in the liver were induced when a subacute dose of retinyl acetate was administered. Histopathological alterations were probably attributable either to accumulation of retinyl esters or effect of mediators released from activated leucocytes at an early stage.

Animals↗

PubMed1998

Adolescent depression in Japan: as studied from Shimoda's theory and Harter's theory.

Through the daily treatment of depressive adolescents we have come to feel that such cases present with a common specific state at onset that includes hypersensitivity and a tendency to neuroticism. This state is reminiscent of the introverted character of children reported by Shimoda in 1929 and of immodithymic character that he later proposed as the pre-pathological character of bipolar disorders. In contrast, we supposed that it might be important to evaluate these adolescents from the low self-worth theory and to compare adolescent psychopathology between the USA and Japan. In order to ascertain these issues, we performed a clinical survey of the junior and high school students who came to outpatient clinics, and thereby demonstrated the necessity of understanding the depressive adolescents from the standpoint of character theory and self-worth theory. We then attempted some field work with ordinary junior high school children as object using Harter's self-perception profile and Kovac's CDI. The results showed that depressive tendencies and self-worth differed greatly among Japanese junior high school children and American counterparts. We have used these findings to discuss the psychopathology of depressive tendencies in Japanese adolescents.

Adolescent↗

PubMed1998

Matrix-producing carcinoma of the breast: case report with radiographical and cytopathological features.

A case of matrix-producing carcinoma (MPC), which is a unique variant of breast cancer, is described with cytopathological and radiographical findings. A 75-year-old female presented with a palpable mass in her right breast. After confirmation of the cytopathological diagnosis, the patient received a right mastectomy with ipsilateral axillary lymph node dissection. The histopathological examination revealed MPC. The Union Internationalis Contra Cancrum postoperative clinical stage was IIB. The patient is well and without disease 18 months after the surgery.

Aged↗

PubMed1998

Setback phenomenon in autism and long-term prognosis.

From among the subjects of a follow-up study on cases of autism conducted by the authors in 1990, 179 cases for which precise records were available on the infancy period were selected for evaluation of the relationship between the occurrence of setback phenomenon in infancy and long-term prognosis. The following results were obtained: (i) a significantly higher rate of epilepsy among the setback group compared to the non-setback group; and (ii) a significantly lower level of language development among the setback group upon entering elementary school compared to the non-setback group, although the difference between the present levels of adaptation of the two groups was not significant. Factors determining the long-term prognosis of the setback group are discussed.

Autistic Disorder↗

PubMed1998

Dexamethasone prevents the decrease of bone mineral density in type II collagen-induced rat arthritis model.

This study demonstrated the decrease of bone mineral density (BMD) in the type II collagen (CII)-induced arthritis (CIA) model in rats and the relationship between BMD and paw edema and the effect of dexamethasone-21-phosphate (DEX). The paw swelling occurred on Day 10 and reached its peak on Day 18 after CII injection. BMD in the CII-injected group is lower than that in the control group. BMD in the proximal and distal regions of the femur largely decreased in comparison with that of the middle region. The oral administration of DEX (0.1 mg/kg) inhibited the swelling and decrease of BMD in all three regions of the femur.

Animals↗

PubMed1998

Synthesis of artificial N-glycopolypeptides carrying N-acetyllactosamine and related compounds and their specific interactions with lectins.

Artificial N-glycopolypeptides carrying N-acetyllactosamine (LacNAc) or related compounds were synthesized. First, sugars were converted into their corresponding beta-glycosylamines with ammonium hydrogen carbonate. Then, the beta-glycosylamines were condensated with the carboxyl groups of poly(L-glutamic acid). N-Glycopolypeptides with different degrees of substitution of sugars were isolated by passage through a column of Sephadex G-25. These synthetic polymers were used as model compounds in the analysis of oligosaccharide-lectin interactions. Interactions with some lectins were investigated by agar-gel double-diffusion tests and in terms of inhibition of hemagglutination. A glycopolypeptide substituted with LacNAc reacted with Erythrina cristagalli agglutinin (ECA), peanut (Arachis hypogaea) agglutinin (PNA), Ricinus communis agglutinin-120 (RCA120), wheat germ (Triticum vulgaris) agglutinin (WGA) lectins, which recognize either galactosyl or N-acetylglucosamine (GlcNAc) residues. Other synthetic glycopolymers carrying N-acetylisolactosamine, GlcNAc, N,N'-diacetylchitobiose, or N,N', N"-triacetylchitotriose also reacted with WGA, and these last two polymers inhibited hemagglutination most. Of these five glycopolypeptides, only the one substituted with LacNAc reacted with ECA. These sugar-substituted glycopolypeptides interacted specifically with the corresponding lectins, no matter how much shorter the sugar side chains of the glycopolymers were than those of natural glycoproteins.

Agar↗

PubMed1998

Detection of retinyl palmitate and retinol in the liver of mice injected with excessive amounts of retinyl acetate.

The transport of subcutaneously injected retinyl acetate (RA, 100,000 IU/mouse, 105,470 nM) was investigated in male ICR mice (10-week-old) at 0, 3, 6, 12, 18, 24 and 72 hr after a single injection. The retinol and retinyl palmitate levels of liver homogenates, bile in the gallbladder and serum from peripheral blood were measured by high performance liquid chromatography (HPLC) method. Retinyl palmitate in the lipid droplets of hepatocytes and Ito cells was localized by a modified gold chloride staining method. Accumulation of retinyl palmitate peaked at 12 hr post-injection and decreased thereafter until 24 hr post-injection. Fluorescence microscopy revealed many fluorescent vitamin A-containing lipid droplets in hepatocytes around central veins at 12 hr post-injection, but such droplets were not observed in the vehicle control mice or at in the RA-injected mice after 18 hr of injection. Electron microscopic observation also indicated that many retinyl esters-containing lipid droplets were observed in hepatocytes around the central veins at 12 hr post-injection, but no droplets were seen in the controls or 18 hr post-injection. The retinyl palmitate levels in liver homogenates assessed by HPLC decreased from 12 to 24 hr post-injection and increased significantly in bile, while retinol in liver homogenates and serum markedly increased. One of the morphological alterations was intense vacuolization in hepatocyte cell cords from the portal toward the central vein observed at 24 hr post-injection. Transitional lipid droplets between vacuoles and lipid droplets were identified in those hepatocytes. These results of HPLC analysis of retinol and retinyl palmitate in liver homogenates, serum, and bile, together with the results of gold chloride staining suggested that subcutaneously injected RA was first incorporated in hepatocytes at 12 hr and then partially metabolized through vacuoles, transferred into the blood and secreted into the bile over a 24 hr period. Many retinyl esters-containing lipid droplets were visualized in Ito cells at 72 hr post-injection. Most of vitamin A in the liver homogenates measured by HPLC was retinyl palmitate. Therefore, the contents in those lipid droplets might be retinyl palmitate.

Animals↗

PubMed1998

Establishment and characterization of a new cell line derived from feline mammary tumor.

A new cell line designated FRM was established from pleural effusion of a 13-year-old female cat with mammary adenocarcinoma. The cell line exhibited irregular round and polygonal shaped epithelial cells and demonstrated cell growth in a monolayer fashion with a doubling time of 22.4 hr. It possessed a modal chromosome number of 79. The immortality of this cell line was demonstrated using the TRAP assay which revealed a high telomeric activity of these cells. Scatchard analysis revealed quite low levels of estrogen receptors in both tumor mass produced in nude mice and FRM cells. Subcutaneous transplantation of the cells produced localized palpable masses in athymic nude mice within two weeks. This cell line may provide a good model for in vivo and in vitro studies on feline mammary tumors.

Adenocarcinoma↗

PubMed1998

Echocardiographic evaluation of cardiac valvular abnormalities in adults with Down's syndrome.

It is well known that congenital heart abnormalities are common in children with Down's syndrome. However there are few studies on cardiac abnormalities in adults with Down's syndrome. Therefore, we estimated cardiac abnormalities by means of echocardiography in 30 institutionalized Japanese adults with Down's syndrome, but without cardiac symptoms. Two-dimensional echocardiography showed an incidence of 26.7% in mitral valve prolapse and 20% increase of echo brightness in the mitral valve. Doppler echocardiography revealed an incidence of 16.7% in mitral valve regurgitation, and 13.3% in aortic valve regurgitation. Thus, even adults with Down's syndrome who are apparently free of cardiac symptoms may be at risk for valvular disease.

Adult↗

PubMed1998

Residual leukemic cell counts in the bone marrow at the end point of intensive induction therapy may be a prognostic factor for acute myeloblastic leukemia in adults.

Between January 1990 and May 1994, 59 previously untreated adult patients with acute myeloblastic leukemia (AML) were treated with a combination of behenoyl-cytosine-arabinoside (BHAC), daunorubicin (DNR), 6-mercaptopurine (6-MP) and prednisolone (PSL). Forty one patients (69.5%) achieved complete remission (CR). The Kaplan-Meier analysis revealed an actuarial probability for remaining in remission of 36% in patients who achieved remission and a survival of 29% in all patients at 5 years. A favorable factor relative to achieving CR was performance status (P=0.04). In addition the presence of 300 cells/microl or less of residual leukemic cell counts in the bone marrow at the end point of induction therapy tended to favor remission (P=0.06) using the multivariate analysis with a multiple logistic regression model. In addition the residual leukemic cells counts of less than 300/microl in the bone marrow at the end point of induction therapy was the most significant factor for durable remission (P=0.05) by the Cox's proportional hazard model. We concluded that residual leukemic cells counts in the bone marrow at the end point of intensive induction therapy is a valuable prognostic factor for adults receiving response-oriented individualized induction therapy for AML.

Adolescent↗

PubMed1998

Antioxidant vitamin levels in plasma and low density lipoprotein of obese girls.

To investigate the antioxidant status of obese children, we analyzed beta-carotene and alpha-tocopherol levels in plasma and low density lipoprotein (LDL). We also analyzed the fatty acid composition of LDL as a substrate for oxidative stress. The plasma beta-carotene and alpha-tocopherol levels were relatively lower in obese girls than in normal controls. However, the plasma alpha-tocopherol/lipids ratio was significantly lower in obese girls than in normal controls. Both LDL beta-carotene and LDL alpha-tocopherol levels were significantly lower in obese girls than in normal controls, although no obvious differences were observed in plasma levels. In obese girls LDL contained more polyunsaturated fatty acid (PUFA) compared with normal controls. When the peroxidizability index (PI) was calculated to estimate the susceptibility of lipids to oxidative stress, obese girls had significantly higher PI values than normal controls. Both the LDL beta-carotene/PI ratio and the LDL alpha-tocopherol/PI ratio were significantly lower in obese girls than in normal controls. These results indicate the increased susceptibility of LDL to oxidative stress in obese girls which may promote atherosclerosis later in life.

Adolescent↗

PubMed1998

[Extreme decrease of serum total cholesterol and other lipid levels in elderly inpatients].

In this study 112 elderly inpatients (55 men, 57 women) were recruited. 1. Twelve elderly inpatients (5 men, 7 women) aged 82.5 +/- 7.4 years (M +/- SD) were investigated during 3 periods of dietary intake: good intake (period I), tube nutrition (period II) and fasting with intravenous fluid infusion (period III). Calorie, protein, carbohydrate, fat and cholesterol intakes were greater in period I than in periods II and III. Serum total and LDL cholesterols were lowest in period III, when serum HDL cholesterol, triglyceride and total protein were lower in period III than in period I. 2. One hundred elderly inpatients (50 men, 50 women) were divided into 4 groups according to type of decreased serum lipid and a control group. Serum total cholesterol only was decreased in group I, both serum total and HDL cholesterols were decreased in group II, both serum total cholesterol and triglyceride were decreased in group III, all 3 lipids were decreased in group IV and lipid levels did not change in the control group. There were 5 patients in group I, 28 patients in group II, 20 patients in group III, 27 patients in group IV and 20 patients in the control group. The patient's age ranged from 80.3 to 88.4 years and body mass index ranged from 14.7 to 18.4 kg/m2. Serum total protein decreased significantly in groups II-IV, to 5.6 to 5.7 g/dl. Serum total protein, and total cholesterol correlated positively (r = 0.525, p < 0.01), as did Calorie ingestion and serum total cholesterol levels (r = 0.554, p < 0.001). Therefore, severe hypocholesterolemia was accompanied by malnutrition and a decrease in Calorie or cholesterol intake. Serum total cholesterol levels during observation decreased most in group IV, followed by group II similar to serum HDL cholesterol levels. The amount of nutrient intake was smallest in group IV resulting in an extreme lowering of all 3 serum lipid levels.

Aged↗

PubMed1998

Plasma beta-carotene, retinol, and alpha-tocopherol levels in relation to glycemic control of children with insulin-dependent diabetes mellitus.

Plasma beta-carotene, alpha-tocopherol and retinol were measured in 15 female and 5 male children with insulin-dependent diabetes mellitus (IDDM), and the correlations with plasma hemoglobin A1c (HbA1c) and fructosamine were analyzed. Twelve female and 8 male children served as age-matched controls. The plasma beta-carotene and alpha-tocopherol levels of the IDDM children were significantly higher than those of the control children, but there were no differences in plasma retinol or total lipid levels. The plasma beta-carotene level, beta-carotene/retinol ratio and beta-carotene/total lipids ratio each showed significant correlations with serum HbA1c and fructosamine in all subjects studied. Similarly, the plasma alpha-tocopherol level and alpha-tocopherol/total lipids ratio were correlated with these indexes of glycemic control. These findings suggest certain mechanisms may exist to prevent lipid peroxidation and vascular complications in IDDM patients.

Adolescent↗

PubMed1998

Activin antiserum infused into the lateral hypothalamic area affects operant behavior of rats fed lysine-deficient diet.

Rats were trained to maintain a high rate of bar pressing to receive 50-mg pellets of a complete diet when given a lysine-deficient (Lys-def) diet ad libitum. This bar-pressing behavior was significantly inhibited when rats were also allowed ad libitum access to 0.4 M Lys to drink. A brain activin system may modulate motivation to engage in bar-pressing behavior, since previous work has established that antagonism of activin by infusion of inhibin or follistatin, but not activin, into the lateral hypothalamic area (LHA) also inhibits bar-pressing behavior. The present study sought to clarify whether the effect of inhibin or follistatin might be mediated by antagonism of endogenous activin or by a separate direct effect of inhibin or follistatin. Thus, we infused an antiserum, which specifically inhibits activin A activity, into the LHA. Infusion of antiserum greatly inhibited bar-pressing behavior of rats fed a Lys-def diet and was additive with Lys consumption further to decrease bar pressing. Ad libitum Lys consumption was unchanged from control levels, indicating that it is likely that an endogenous activin system in the LHA mediates behavioral responsiveness when rats are fed a Lys-def diet but does not appear specifically to affect appetite for Lys.

Activins↗

PubMed1998

Structure of and signal transduction through interleukin-4 and interleukin-13 receptors (review).

We have recently demonstrated that two different forms of IL-4R exist; classical or alternative. The classical IL-4R is predominantly expressed in hematopoietic cells and consist of IL-4R and IL-2Rgammac (gammac) chains. On the other hand, alternative form of IL-4R is predominantly expressed in non-hematopoietic cells and consists of IL-4R and IL-13Ralpha' chains. Moreover, the alternative form of IL-4R is also utilized as a functional component IL-13R complex. It has been shown that the phosphorylation and activation of JAK3 tyrosine kinase is crucial for IL-4 activation of STAT6 in hematopoietic cells. However, we have recently demonstrated that non-hematopoietic cells lack JAK3 expression. We also demonstrated that in these cells, STAT6 activation is mediated through JAK1 and JAK2 tyrosine kinases instead. Furthermore, our results show that IL-4 and IL-13 signals are transmitted through the alternative form of IL-4R in these cells. Thus, major differences exist between hematopoietic and non-hematopoietic cells with regard to structure and signal transduction through IL-4R and IL-13R systems.

Animals↗

PubMed1998

Analysis of cell kinetics after gamma-ray irradiation using an anti-BrdU monoclonal antibody.

The cell cycle was analyzed using double staining with an anti-bromodeoxyuridine (BrdU) monoclonal antibody and propidium iodide (PI). Changes in cell kinetics after irradiation were compared with those seen by the conventional PI-based DNA histogram method. The effect of irradiation on cell kinetics has been studied primarily by counting G2-arrested cells. By the present BrdU method, a rapid transition from G1 to S-phase was observed within 2 h of irradiation, followed by G1 block. Cells in the S-phase progressed to G2+M where they arrested, resulting in a decreased percentage of S cells (<5%). Release of G1 block occurred after 8 h, and G2+M cells returned to G1 after >18 h. The initial G1 arrest induced by irradiation was confirmed for the first time by the present BrdU-PI double staining.

Antibodies, Monoclonal↗

PubMed1998

Cell kinetic changes in cultured tumor cells after treatment with radiation and chemotherapy.

Flow cytometry instantaneously determines the percentages of cells in various cell cycle phases to rapidly evaluate effects of irradiation and anti-cancer drugs. We studied these using growth curve analysis and 5-bromodeoxyuridine propidium iodine (BrdU)-(PI) double staining. With conventional DNA histogram methods, determination of S phase fraction was difficult because of overlapping DNA content between G1 and early S phases and between late S and G2 phases. Double staining directly differentiated G1, S, and G2 + M phases. By double staining, rapid transition from G1 to S occurred within 4 h after irradiation or after the drug treatments, and initial G1 arrest induced by irradiation was confirmed for the first time.

Antineoplastic Agents↗