Biomedical subjects

T Ueda

Publications and source records attributed to T Ueda.

At least 127 records · Page 7Linked to original sources

PubMed1991

1H-NMR study of the intramolecular interaction of a substrate analogue covalently attached to aspartic acid-101 in lysozyme.

We prepared the lysozyme derivative in which the beta-carboxyl group of Asp101 was modified with alpha-O-methyl N-glycylglucosaminide as an amide by means of the carbodimide reaction (alpha-MGG lysozyme). Since Asp101 residue is located at the edge of the active site cleft, a 1H-NMR study was carried out for this derivative in order to investigate the interaction between the introduced substituent and the active site cleft. It was confirmed that the alpha-MGG moiety sat in the active site cleft in alpha-MGG lysozyme from the reduction of line broadening of the NH-proton of Trp63 located in the active site cleft, the remarkable chemical shift change of the methyl group of the alpha-MGG moiety upon adding a trimer of N-acetyl-D-glucosamine [(NAG)3], and the NOE between the C6-proton resonance of Trp63 and the methyl resonance of the alpha-MGG moiety. Furthermore, alpha-MGG lysozyme had increased thermal stability compared with native lysozyme. Therefore, it was concluded that the alpha-MGG moiety covalently attached to Asp101 interacted with the active site cleft to increase the thermal stability of lysozyme.

Animals↗

PubMed1991

Preparation and properties of a lysozyme derivative in which two domains are cross-linked intramolecularly between Trp62 and Asp101.

A lysozyme derivative in which two domains were cross-linked intramolecularly was newly prepared by means of a two-step reaction. First, the beta-carboxyl group of Asp101 in lysozyme was selectively modified with 2-(2-pyridyldithio)ethylamine in the presence of 1-ethyl-3-[3-(dimethylamino)propyl]carbodiimide hydrochloride. After reduction of the pyridyldithio moiety of Asp101 modified lysozyme at pH 4.5 with dithiothreitol, the derivative was allowed to cross-link intramolecularly by reaction with 1,3-dichloroacetone at pH 7. Intramolecularly cross-linked lysozyme thus formed was purified by gel chromatography followed by ion-exchange chromatography. Based on the results of 1H-NMR and peptide analyses, it was concluded that Asp101 was cross-linked to Trp62 with a -CH2COCH2SCH2CH2NH-bridge in this derivative. The derivative showed minor but distinct activity against Micrococcus lysodeikticus and glycol chitin. Its melting temperature for thermal denaturation was higher by 7.3 degrees than that of native lysozyme at pH 3.

Amino Acid Sequence↗

PubMed1991

Histological factors contributing to favorable prognoses of soft tissue sarcomas in premenopausal patients.

The correlations of sex with various histologic factors in soft tissue sarcomas (STS) were studied in 142 adult patients over the age of 20 years. They included 63 with malignant fibrous histiocytomas, 20 with liposarcomas, 20 with synovial sarcomas, 11 with malignant Schwannomas and 28 with other forms of STS. These were divided into four groups, according to age (20-49 years and greater than or equal to 50 years) and sex. Survival rates in female patients were better than those in male patients, and the difference was significant between the 20-49 year groups (p less than 0.01). The relative frequencies in distribution of each histologic type were similar among male and female patients in both age groups. Among histological factors, mitotic counts showed a significant correlation (P less than 0.04) with sex, followed by cellularity. STS in female patients aged 20-49 years had lower mitotic counts than in patients in other groups, where it occurred with a higher frequency of low and intermediate grade tumors. The findings suggested estrogen, either directly to indirectly, to have a favorable effect on STS prognosis in premenopausal female patients.

Adult↗

PubMed1991

Plasma endothelin levels in healthy children: high values in early infancy.

We measured plasma endothelin-1-like immunoreactivity (ET-1-LI) levels in the peripheral vein of 70 healthy children (37 males and 33 females) aged 5 days to 15 years to establish the normal range in children, and compared them with those in 11 normal adults (age, mean +/- SD; 29.5 +/- 5.7 years, 6 males and 5 females). Plasma ET-1-LI levels (pg/ml, mean +/- SD) in children of each age group and adults were as follows: children younger than 1 month = 23.4 +/- 3.9 (n = 10), 1-3 months = 25.0 +/- 6.1 (n = 8), 3-6 months = 17.0 +/- 1.4 (n = 8), 6 months to 1 year = 14.0 +/- 1.7 (n = 13), 1-5 years = 13.8 +/- 2.6 (n = 11), 5-10 years = 13.6 +/- 1.6 (n = 10), 10-15 years = 12.9 +/- 2.2 (n = 10), and adults = 13.2 +/- 2.4 (n = 11). There was no significant difference in plasma ET-1-LI levels between males and females in each age group. Plasma ET-1-LI levels in children younger than 3 months were significantly (p less than 0.01) higher than those in older children or adults. After 3 months of age, plasma ET-1-LI levels were nearly constant at all ages. This is the first report to establish the normal range of plasma ET-1-LI levels in children.

Adolescent↗

PubMed1991

Efficacy of bypass between extracerebral artery and cerebral vein with retrograde verapamil infusion into focal cerebral ischemic tissue in rats.

We examined the efficacy of a bypass from an extracerebral artery to a cerebral vein (EA-CV) with retrograde verapamil infusion on acute focal cerebral ischemia in 35 rats. In 12 rats, within 1 hour after occlusion of the middle cerebral artery (MCAO), changes in blood-brain barrier permeability were examined by [14C]alpha-aminoisobutyric acid autoradiography after EA-CV bypass surgery; there were no significant changes during a period of 2 hours after EA-CV bypass. The other 18 rats having MCAO were divided into three groups of six each. Group A rats (control) underwent only cannulation of the cerebral vein. Group B rats had an EA-CV bypass. Group C rats received verapamil (0.1 mg/kg every 2 h) by transvenous perfusion of the brain (TVPOB) through the EA-CV bypass. In all rats in Groups A and C, local cerebral blood flow (LCBF) and quantitative measurement of early cerebral infarct volume were performed by autoradiography using [14C]iodoantipyrine and histochemical staining methods. Group B rats were examined only with the LCBF measurement. Group B (EA-CV bypass only) showed a nonsignificant improvement (18-40%) of LCBF in the ischemic cerebral cortical areas as compared with control Group A. Group C (EA-CV bypass with TVPOB with verapamil) showed an extensive and significant improvement in LCBF in the ischemic cortical areas (115-140%; P less than 0.05) and a slight increase in LCBF in the subcortical areas (17-29%), with a significant reduction (greater than 35%; P less than 0.05) in a total cerebral infarct volume in the ischemic cerebral hemisphere as compared with the control Group A.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1991

Measurement of hepatic blood flow by use of per-rectal portal scintigraphy with 133Xe.

A relatively noninvasive method is needed to evaluate the hepatic blood flow of patients with liver disease. We used per-rectal portal scintigraphy with 133Xe, and analysed the time-activity curves of the liver and portal vein. To do this, wash-out curves of the liver were plotted, and the hepatic blood flow and the ratio of the blood flow to the right lobe of the liver to that to the left lobe (R/L ratio) were calculated. The mean hepatic blood flow was 137 +/- 23 ml/100 g/min for four patients with fatty liver, 139 +/- 16 ml/100 g/min for seven patients with chronic persistent hepatitis, 120 +/- 15 ml/100 g/min for ten patients with chronic aggressive hepatitis, and 75 +/- 21 ml/100 g/min for 14 patients with cirrhosis. All seven patients with hepatic blood flow that was less than 100 ml/100 g/min and an R/L ratio less than 1.0 had cirrhosis. Only two of the 22 patients with hepatic blood flow that was greater than 100 ml/100 g/min and an R/L ratio greater than 1.0 had cirrhosis. Per-rectal portal scintigraphy can be used to measure the hepatic blood flow, but it was not useful for the diagnosis of fatty liver.

Administration, Rectal↗

PubMed1991

Beta-adrenergic stimulation induces intracellular Ca++ increase in human epidermal keratinocytes.

Intracellular Ca++ ([Ca++]i) is one of the most important second messengers of extracellular signals that induce cellular responses. In epidermal keratinocytes, both extracellular and intracellular Ca++ are reported to be important to cell differentiation and proliferation. Several mechanisms that increase [Ca++]i have been elicited in various tissues; however, in epidermal keratinocytes they remain unknown. Thus, we investigated the [Ca++]i modulation in cultured human epidermal keratinocytes and the stimulation that increases the concentration. The [Ca++]i concentration of keratinocytes was increased immediately and transiently by epinephrine. Methoxamine hydrochloride and clonidine (alpha-1- and 2-adrenergic agonists) did not induce an increase in [Ca++]i. The beta-antagonist, propranolol, inhibited the [Ca++]i increase induced by epinephrine and salbutamol (a beta-2-agonist). These results reveal that the beta-adrenergic stimulation induces an immediate and transient [Ca++]i increase in human keratinocytes. Beta-adrenergic stimulation is known to induce adenylate cyclase activation, which results in cyclic AMP accumulation through stimulatory guanosine 5-triphosphate (GTP) binding proteins in the keratinocytes. Also, epinephrine is reported to inhibit cultured epidermal cell proliferation. The effect of epinephrine has been demonstrated by cyclic AMP accumulation; however, beta-adrenergic stimulation revealed a [Ca++]i increase in keratinocytes in our study. One of epinephrine's regulatory effects on epidermal cell proliferation is assumed to occur through the [Ca++]i increase as well.

Adrenergic beta-Antagonists↗

PubMed1991

Comparison of clinical and pathological characteristics in incidentally detected and suspected renal carcinoma.

In a study of the clinical and pathological characteristics of incidentally detected and suspected renal carcinoma, we reviewed the manner of presentation, serum immunosuppressive acidic protein (IAP), tumour stage and size in 112 consecutive patients with renal carcinoma who were diagnosed clinically and surgically between 1980 and 1989. The results showed an increase in the proportion of incidentally diagnosed cases. The routine use of radiological imaging, especially ultrasound and computed tomography (CT), has led to tumours being diagnosed earlier than when IAP is used as a tumour marker in patients with incidentally detected renal carcinoma. Tumours were lower stage and smaller in patients with incidentally detected renal carcinoma than in patients in whom the diagnosis was suspected.

Adult↗

PubMed1991

Phosphoglycerates and protein phosphorylation: identification of a protein substrate as glucose-1,6-bisphosphate synthetase.

We have previously reported the occurrence of two endogenous protein phosphorylation systems in mammalian brain that are enhanced in the presence of 3-phosphoglycerate (3PG) and ATP. We present here a study of one of these systems, the phosphorylation of the 72-kDa protein (3PG-PP72). This system was separated into the substrate, 3PG-PP72, and a kinase by ammonium sulfate fractionation, hydroxyapatite chromatography, and hydrophobic interaction HPLC. The substrate protein was shown to be directly phosphorylated with [1-32P]1,3-bisphosphoglycerate [( 1-32P]1,3BPG) with an apparent Km of 1.1 nM. Nonradioactive 1,3BPG inhibited 32P incorporation in the presence of [gamma-32P]ATP and 3PG. Phosphopeptide mapping and phosphoamino acid analyses indicated that the site of phosphorylation of 3PG-PP72 observed in the presence of 3PG and ATP is a serine residue identical to that observed with [1-32P]1,3BPG. Moreover, [32P]phosphate incorporated into 3PG-PP72 in the presence of 3PG and ATP was removed by subsequent incubation with glucose-1-phosphate or glucose-6-phosphate. Finally, 3PG-PP72 showed chromatographic behaviors identical to those of glucose-1,6-bisphosphate (G1,6P2) synthetase. Based upon these observations, we conclude that 3PG-PP72 is G1,6P2 synthetase and that it is phosphorylated directly by 1,3BPG, which is formed from 3PG and ATP by 3PG kinase present in a crude 3PG-PP72 preparation.

Amino Acids↗

PubMed1991

[Hospital spread of scabies from an immunocompromised patient with Norwegian scabies].

Scabies was first found in a 71-year-old female who had been diagnosed as having leukemic transformation of primary myelofibrosis and had undergone treatment for the disease. She was admitted to the hospital in December 1986, because of abdominal fullness and a generalized subcutaneous tumor that proved to be myeloblastoma. For treatment of the underlying disease, the regimen of the combination of vindesine, cyclophosphamide, 6-mercaptopurine, and prednisolone was selected. She developed cardiac failure and fell into a coma one month after starting the anticancer therapy. She was put on artificial respiration and on additional steroid therapy as well. Dexamethasone was administrated at 16 mg/day. Since the myeloblastomas found on admission regressed, the steroid therapy was continued. She was in coma for a few days before her skin lesions turned red and formed a grayish crust in the lower abdominal region. Several days later, the doctor responsible for the treatment of this patient developed pruritus and exanthema on both arms, and soon many nurses in the same hospital-ward developed similar symptoms. At approximately the same time, the patient with myelofibrosis was diagnosed as having Norwegian scabies: the crusted skin lesions revealing many Sarcoptes scabiei mites. Two doctors (2/18), 17 nurses (17/19) and 3 other patients (3/51) were found to have contracted scabies, and we recognized the hospital spread of the infection. The first patient was isolated in a private room, and we avoided direct contact with her. The persons with scabies were treated with crotamiton liniment. The first scabies patient died of cardiac failure 1 month after falling into a coma.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1991

Antiviral activities of 5-ethynyl-1-beta-D-ribofuranosylimidazole-4- carboxamide and related compounds.

A series of novel compounds, 5-alkynyl-1-beta-D-ribofuranosylimidazole-4- carboxamides, have been identified as broad-spectrum antiviral agents. 5-Ethynyl-1-beta-D-ribofuranosylimidazole-4- carboxamide (EICAR), the most potent congener of the group, showed antiviral potency about 10- to 100-fold greater than that of ribavirin. Similar in spectrum to ribavirin, EICAR was particularly active (50% inhibitory concentration, 0.2 to 4 micrograms/ml) against poxviruses (vaccinia virus), togaviruses (Sindbis and Semliki forest viruses), arenaviruses (Junin and Tacaribe viruses), reoviruses (reovirus type 1), orthomyxoviruses (influenza A and B viruses), and paramyxoviruses (parainfluenza virus type 3, measles virus, subacute sclerosing panencephalitis virus, and respiratory syncytial virus). EICAR was also cytostatic for rapidly growing cells (50% inhibitory concentration, 0.2 to 0.9 microgram/ml). EICAR inhibited vaccinia virus tail lesion formation at doses that were not toxic to the host. EICAR is a candidate antiviral drug for the treatment of pox-, toga-, arena-, reo-, orthomyxo, and paramyxovirus infections.

Adenosylhomocysteinase↗

PubMed1991

Incomplete testicular feminization syndrome. A case occurring in a family with frequent hypospadias.

The case of a 16-year-old patient with incomplete testicular feminization syndrome is reported. The patient had phenotypically female genitalia except for clitoromegaly. Hormonal examinations revealed low plasma testosterone levels but a normal concentration of 5 alpha-dihydrotestosterone, and radiological and surgical examinations revealed no development of Müllerian structures including the uterus and the adnexa. This happened in a family with a frequent occurrence of both hypospadias and cryptorchism.

Adolescent↗

PubMed1991

Recurrence of bladder tumors following surgery for transitional cell carcinoma of the upper urinary tract.

A retrospective analysis of 53 patients with an upper urinary tract (UUT) transitional cell carcinoma, which was treated surgically, was performed in relation to the development of a subsequent bladder tumor. In 19 of the 53 patients (35.8%) bladder tumors developed following surgery of a UUT tumor. The simultaneous occurrence of a bladder tumor and more than two tumors in the UUT had a significant influence on the rate of bladder tumor recurrence. On the other hand, location, mode of growth, grade, stage and vascular invasion of the UUT tumor, and history of bladder tumors did not seem to be related to the frequency of subsequent bladder tumors. These findings suggest that the diversity of UUT tumors at the time of diagnosis is an important factor in bladder tumor recurrence. Therefore, clinical and pathological examinations should be carefully performed in patients with UUT tumors.

Aged↗

PubMed1991

Plasma endothelin concentrations in patients with pulmonary hypertension associated with congenital heart defects. Evidence for increased production of endothelin in pulmonary circulation.

BACKGROUND: To elucidate the pathophysiological significance of endothelin in pulmonary hypertension associated with congenital heart defects, we measured plasma endothelin-like immunoreactivity (ET-LI) concentrations by using radioimmunoassay in 18 patients with pulmonary hypertension (PH group; age, 6 months to 12 years) in comparison with 27 patients without pulmonary hypertension (non-PH group; age, 6 months to 12 years). METHODS AND RESULTS: Blood samples were obtained from the vena cava, right atrium, right ventricle, left or right pulmonary artery, and pulmonary vein or the pulmonary arterial wedge position (pulmonary venous blood) during cardiac catheterization. Plasma ET-LI concentrations in the PH group were significantly higher than those in the non-PH group at all sampling sites. In the PH group, plasma ET-LI concentration showed a significant increase between the right ventricle and pulmonary artery and between the pulmonary artery and pulmonary vein. The increment of plasma ET-LI concentrations from the right ventricle to the pulmonary vein was significantly larger in the PH group than in the non-PH group and was significantly correlated with pulmonary artery pressure. CONCLUSIONS: Plasma ET-LI concentrations were elevated in patients with pulmonary hypertension; the elevation was due to the increased production of ET-LI in pulmonary circulation, indicating the possible involvement of endothelin in the pathophysiology of pulmonary hypertension.

Blood Pressure↗

PubMed1991

Protein adsorption on biomedical polymers with a phosphorylcholine moiety adsorbed with phospholipid.

The effects of phospholipid adsorption onto the polymer surface during adsorption of plasma proteins were investigated. When a polymer with the phosphorylcholine moiety, 2-methacryloyloxyethyl phosphorylcholine (MPC) co-polymer, was treated with dipalmitoylphosphatidylcholine (DPPC) liposome solution, an organized adsorption layer of DPPC was formed on the MPC co-polymer surface, which was confirmed by differential scanning calorimetric analysis and X-ray photoelectron spectroscopy. On the other hand, an organized layer of DPPC on poly(n-butyl methacrylate) and poly(2-hydroxyethyl methacrylate) could not be found. The amount of albumin adsorbed on the polymer surfaces was decreased by pretreatment of the surface with DPPC liposome solution in every polymer case. The smallest amount of adsorbed proteins was found on the MPC co-polymer. Protein adsorption on the surface of MPC co-polymers from the plasma was also small. The difference in protein adsorption on the polymers probably reflects the difference in the orientation of the phospholipid molecules which cover the polymer surface.

Adsorption↗

PubMed1991

Inherited type of allelic methylation variations in a mouse chromosome region where an integrated transgene shows methylation imprinting.

It is still unclear whether or not parent-of-origin-dependent differential methylation observed in some transgenes reflects genomic imprinting of endogenous genes. We have characterized a transgene locus showing such methylation imprinting together with the corresponding native chromosome region. We show that only part of the transgene is affected by methylation imprinting and the methylation pattern is established before early prophase I during spermatogenesis. Interestingly, the native genomic region, which is mapped to the proximal chromosome 11, shows no evidence of methylation imprinting but displays heritable, strain-specific type of allelic methylation differences. The results demonstrate that transgenes do not necessarily reflect the methylation status of either the surrounding or corresponding chromosome region. In addition, inherited type of allelic methylation variations previously described in human may be widespread in mammals.

Animals↗

PubMed1991

Studies on the chemical modification of monensin. III. Synthesis and sodium ion transport activity of macrocyclic monensylamino acid-1,29-lactones.

Monensylglycine (2a) was lactonized to macrocyclic monensylglycine-1,29-lactone (3a) by Corey's method. Lactonization of monensylamino acids (2b--d) to monensylamino acid-1,29-lactones (3b--d) was carried out by utilizing the template effect of K+ ion. Monobenzyl esters of dicarboxylic monensylamino acids (5e--f) also were lactonized followed by debenzylation to yield carboxylic monensylamino acid-1,29-lactones (3e--f). Sodium ion transport activity of monensin (1) and the lactones (3) was measured in a liquid membrane and in guinea pig erythrocyte membrane. Monensylaspartic acid-1,29-lactone (3e) exhibited 2.5 times higher activity than 1 in the liquid membrane. Monensylalanine-1,29-lactone (3b), monensylphenylalanine-1,29-lactone (3c), and monensyltyrosine-1,29-lactone (3d), having smaller Na+ ion transport activity than 3e, showed weak antibacterial activity, while 3e was inactive in biological tests, probably due to the lower lipophilicity.

Animals↗

PubMed1991

Studies on cardiac ingredients of plants. VII: Chemical transformation of proscillaridin by means of the Diels-Alder reaction and biological activities of its derivatives.

The Diels-Alder reactions of a cardiac glycoside, proscillaridin (1), with some dienophiles were investigated. The reaction of 1 with alkenes such as methyl vinyl ketone and methyl acrylate afforded 3-oxo-2-oxabicyclo[2.2.2]oct-7-enes (2-5) and para-substituted benzene derivatives (6 and 7), while 1 reacted with alkynes (3-butyn-2-one, methyl propiolate) to yield para- or meta-substituted benzene derivatives (6-9). The biological activities of the resulting derivatives were evaluated by the use of isolated guinea-pig papillary muscle preparations and Na+,K(+)-adenosine triphosphatase (ATPase) preparation from dog kidney. Among the proscillaridin derivatives, compounds 4 and 7 moderately inhibited Na+,K(+)-ATPase activity. Furthermore, the concentration range of 7 over which its positive inotropic effect on guinea-pig papillary muscle preparations, increased from 5% to 95% of maximum was broader than that of 1, i.e., concentration dependency was maintained over a greater range of concentration.

Adenosine Triphosphatases↗