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Biomedical subjects

H Hirata

Publications and source records attributed to H Hirata.

At least 199 records · Page 11Linked to original sources
PubMed1991

Detection of circulating intercellular adhesion molecule-1 antigen in malignant diseases.

A new monoclonal antibody (MoAb) HA58 (IgG1) was prepared, which recognizes the binding site on the intercellular adhesion molecule-1 (ICAM-1) antigen to the lymphocyte function-associated antigen-1 (LFA-1). The double-determinant immunoassay (DDIA) was established with use of MoAb HA58 and another anti-ICAM-1, MoAb CL207, to detect the soluble, shedding ICAM-1 antigen. Human recombinant interferon-gamma (IFN-gamma) induced not only the expression of cell surface ICAM-1, but also the shedding ICAM-1 antigen in an IFN-gamma concentration-dependent and incubation-time-dependent manner. DDIA was applied to detect the shedding ICAM-1 antigen in the sera of patients with malignant or benign diseases. The incidence of positivity for ICAM-1 antigen in malignant diseases was higher than that in benign diseases or in healthy controls. Furthermore, the sera of cancer patients with liver metastasis showed higher levels of the shedding ICAM-1 antigen. These findings suggest that serum ICAM-1 antigen may be a useful marker to monitor tumor burden in cancer patients.

Adult↗
PubMed1991

Effects of beta-adrenergic blocking agents on specific binding of [3H]D-Ala2-Met5-enkephalinamide and [3H]naloxone.

To gain further insight into the central nervous system (CNS)-action of beta-adrenergic blocking agents (beta-blockers), we examined the effects of various kinds of beta-blockers on opioid receptors (Op-Rs) using radiolabeled receptor assay (RRA). We demonstrated that beta-blockers are competitively bound to Op-Rs in the CNS. Sodium index of beta-blockers in [3H]naloxone binding study indicated that beta-blockers had the mixed agonist-antagonist activity of opiates. The relative potency of beta-blockers in opioid RRA was negatively correlated with their membrane stabilizing activity. Neither beta-blocking activity nor intrinsic sympathomimetic activity was correlated with IC50 values of beta-blockers in opioid RRA. While it is widely accepted that beta-blockers have a tranquilizing activity, a part of the tranquilizing action of beta-blockers may be mediated through Op-Rs in the CNS. Although beta-blockers may have effects on their own receptors (beta-receptors) in the CNS, the more precise mechanisms of central action of these drugs must be further investigated.

Adrenergic beta-Antagonists↗
PubMed1991

Dopamine deficiency in the weaver mutant mouse: an animal model of olivopontocerebellar atrophy.

The dopamine system in weaver mutant mice, a model of cerebellar atrophy, was studied. Dopamine levels of 6-week-old weaver mice were 37%, 44%, 34%, and 41% of levels in age-matched controls in the cerebral cortex, hippocampus, septal region and striatum, respectively. Noradrenaline levels did not differ from controls. This study shows that weaver mice have specific deficiencies in the dopamine system.

Analysis of Variance↗
PubMed1991

[Nine month chemotherapy with INH and rifampicin for non-cavitary pulmonary tuberculosis].

In order to know the adequate duration of the chemotherapy with two drugs (INH + RFP) for pulmonary tuberculosis with non-cavitary minimal radiological findings (minimal case), 278 cases with minimal lesion which had completed 9 months' chemotherapy, were observed for more than six months up to 5 years (mean duration = 54.4 months). Of them, 60 cases were bacteriologically confirmed by smear and/or culture examination. Many cases showed further improvement in radiological findings even after the end of the chemotherapy. Of 180 cases of initially infiltrative type (GAKKEN B type), 10 cases showed the enlargement of shadow radiologically, but were not regarded as relapsed cases, because they remained bacteriologically negative and the shadow improved in 1-2 months without additional chemotherapy. Only 3 cases (1.1%) were regarded as relapsed cases because of the positive bacteriological conversion and aggravation of the shadow. They were initially sputum negative. It can be concluded that for radiological minimal cases, nine months is enough for the duration of chemotherapy when the INH-RFP regimen is used.

Adolescent↗
PubMed1990

Hydrophobic residues 382-386 of antithrombin III, Ala-Ala-Ala-Ser-Thr, serve as the epitope for an antibody which facilitates hydrolysis of the inhibitor by thrombin.

In the presence of a monoclonal antibody raised against the human thrombin-antithrombin III complex, the reaction between thrombin and antithrombin III proceeded to form preferentially a two-chain form of the inhibitor rather than to follow the major pathway of stable acyl complex formation. We thus propose the term "switching antibody" for an antibody that switches the enzyme-inhibitor reaction (Asakura, S., Matsuda, M., Yoshida, N., Terukina, S., and Kihara, H. (1989) J. Biol. Chem. 264, 13736-13739). By analyzing a CNBr fragment of the thrombin-antithrombin III complex that reacts with the antibody we localized the epitope for the antibody to a strongly hydrophobic residue 382-386 peptide segment, Ala-Ala-Ala-Ser-Thr, of the inhibitor, which is also contiguous with a hydrophobic amino acid Ala at its carboxyl terminus. This particular region should be cryptic in nascent antithrombin III, but could have been exposed to provide the reactive site for the antibody at an early stage of the reaction. Thereby a conformational change may have been induced at or near the reactive site of the complex, facilitating hydrolysis of the inhibitor by the enzyme. Interestingly, this hydrophobic region is highly conserved among members of the serpin family.

Amino Acid Sequence↗
PubMed1990

Clinicopathologic and immunohistochemical characteristics of bronchial gland cell type adenocarcinoma of the lung.

Twenty-three cases of bronchial gland cell (BGC) type lung adenocarcinoma were examined clinicopathologically and immunohistochemically. BGC type adenocarcinoma was defined as adenocarcinoma showing histologic and cytologic differentiation toward the bronchial gland. This type of adenocarcinoma occurred more frequently in younger patients (mean age, 50.5 years) than in patients with other types of adenocarcinoma (mean age, 60.1 years). It had a tendency to arise from relatively large bronchi and show endobronchial growth. However, there was no difference in disease stage based on tumor, nodal involvement, metastases (TNM) factors and outcome between BGC type adenocarcinoma and peripheral type adenocarcinoma. Immunohistochemically, 50%, 68%, and 64% of BGC type adenocarcinomas were positive for carcinoembryonic antigen, surfactant apoprotein, and secretory component, respectively. Peripheral type adenocarcinomas showed similar rates of immunohistochemical stainability of these antigens. The positive reaction of BGC type adenocarcinomas with anti-surfactant apoprotein antibody may indicate maintenance of traces of differentiation toward peripheral airway epithelium. Lactoferrin is characteristically detected in BGC type adenocarcinomas, although the positive rate was not very high.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed1990

Partial amino acid sequence of an amyloid fibril protein from nodular primary cutaneous amyloidosis showing homology to lambda immunoglobulin light chain of variable subgroup III (a lambda III).

An amyloid fibril protein (MA) was purified as a 17,000-dalton protein from a case of nodular primary cutaneous amyloidosis, and its partial amino acid sequence (22 residues from N-terminal) was determined. A sequence closely homologous to that of the lambda III subgroup of the immunoglobulin light chain was detected. This is the third case of nodular primary cutaneous amyloidosis which has been studied at the level of sequence analysis of purified amyloid fibril proteins, and the first case of nodular primary cutaneous amyloidosis in which a lambda III amyloid protein has been shown to be present by sequence analysis.

Amino Acid Sequence↗
PubMed1990

Orosomucoid (ORM) typing by isoelectric focusing: an analysis of ORM haplotypes.

A new separator isoelectric focusing method for typing of orosomucoid (ORM) was developed. This method provided a superior resolution of ORM patterns: two close bands of ORM1*5.2 products were clearly separated. A total of 364 subjects from Okinawa (Japan) were classified into 21 ORM phenotypes determined by 6 ORM1 and 7 ORM2 alleles including a polymorphic silent allele, ORM2*QO, and 2 new rare variants, ORM2*18 and ORM2*19. These phenotypes were also explained by 12 ORM haplotypes, half of which were polymorphic.

Gene Frequency↗
PubMed1990

Clinical significance of the number of positive tumor markers in assisting the diagnosis of lung cancer with multiple tumor marker assay.

The clinical significance of multiple tumor marker assay in assisting the diagnosis of lung cancer was assessed in 67 patients with primary lung cancer, and 115 with nonmalignant pulmonary disease. The tumor markers studied were carbohydrate antigen 19-9 (CA19-9), carcinoembryonic antigen (CEA), neuron-specific enolase (NSE), squamous cell carcinoma-related antigen (SCC), and tissue polypeptide antigen (TPA). The positive rates for all of the tumor markers were significantly higher in the lung cancer group than in the nonmalignant pulmonary disease group. The sensitivity was 31-66%, the specificity was more than 90% for all five markers, and the accuracy was 69-82%. Among the markers, the positive rate of CEA was best correlated with adenocarcinoma (Ad), NSE with small cell carcinoma (Sm), SCC with squamous cell carcinoma (Sq), CA19-9 with Ad, and TPA with Ad. In multiple tumor marker assay, as the number of combined markers was increased, the sensitivity of the assay became higher and the specificity became lower, resulting in a lower accuracy. However, when more than two markers were positive, the relative possibility of lung cancer was increased 90-100%. The number of positive tumor markers in multiple tumor marker assay indicated that it would be of auxiliary value for the diagnosis of lung cancer.

Antigens, Neoplasm↗
PubMed1990

[Mesenteric hematoma; a pediatric case].

A 3-Year-old girl was admitted to National Beppu Hospital due to abdominal mass. US examination revealed cystic mass with multiple scattered nonreverberatory echoes in right upper abdomen. CT examination revealed almost homogeneous mass (29-31 H.U.) with a few internal components (36-42 H.U.). US and CT were useful methods for diagnosis of mesenteric hematoma.

Child, Preschool↗
PubMed1990

High-level expression of complementary DNA encoding rat calmodulin in Escherichia coli.

We report the production and characterization of a rat calmodulin made in Escherichia coli. To express the rat calmodulin cDNA in E. coli, we have employed an expression vector containing the E. coli trp promoter and trpA terminator. The cDNA was modified so as to delete the 5' nontranslated sequence and to incorporate a consensus sequence for the E. coli ribosome-binding site. Several codons for the N-terminal amino acids were selected to fit the E. coli consensus nucleotide sequence around the translational initiation codon. After induction of expression in E. coli, rat calmodulin accounted for over 30% of total cellular proteins. About 100 mg of recombinant rat calmodulin, purified to over 90% homogeneity by extraction from bacterial lysate followed by phenyl-Sepharose column chromatography, was obtained from 1 liter of E. coli culture. This recombinant calmodulin activated rat brain cyclic AMP phosphodiesterase to the same extent as the native calmodulin purified from rat brain. These results indicate that the overproduction system of the recombinant calmodulin in E. coli facilitates the study of the structure-function relationship by site-specific mutagenesis.

Amino Acid Sequence↗
PubMed1989

Cyclic nucleotides and GTP analogues stimulate light-induced phosphorylation of octopus rhodopsin.

Light-induced phosphorylation of octopus rhodopsin in microvillar membrane was shown to be stimulated by cyclic nucleotides in contrast to vertebrate rhodopsin kinase. Non-hydrolyzable GTP analogues, GTP lambda S and GppNHp, greatly enhanced the light-induced phosphorylation of octopus rhodopsin, but the non-hydrolyzable GDP analogue, GDP beta S, was not effective. These results suggest that rhodopsin A-kinase is involved in regulating the interaction between rhodopsin and G-protein in octopus photoreceptors.

Animals↗
PubMed1989

New substrate specificity of modified porcine pancreatic alpha-amylase.

Conversion of the substrate specificity of porcine pancreatic alpha-amylase (PPA) was studied using chemical modification of His residues. Diethyl pyrocarbonate modified His residues in PPA and the activity of the modified PPA for the hydrolysis of the alpha-D-(1,4)glucoside bond in starch or oligosaccharides decreased to less than 1% of that of the native enzyme. However, the activity for the hydrolysis of the bond between p-nitrophenol and oligosaccharides in p-nitrophenyl oligosaccharides was increased by chemical modification. When the modified PPA was incubated with a proteinaceous alpha-amylase inhibitor (Mr 60,000) purified from white kidney bean (Phaseolus vulgaris), it bound to the inhibitor. As a result, the remaining less than 1% hydrolytic activity of the modified PPA for starch disappeared completely but that for p-nitrophenyl oligosaccharides remained unaltered. The hydrolytic activity of the native PPA for the alpha-D-(1,4)glucoside bond in oligosaccharides was stronger than that between p-nitrophenyl and oligosaccharides in p-nitrophenyl oligosaccharides. Therefore, when p-nitrophenyl oligosaccharides (three to five glucose residues) were used as substrates for the native PPA, the alpha-D-(1,4)glucoside bonds in the oligosaccharides were hydrolyzed. However, the modified PPA-inhibitor complex hydrolyzed only the bond between p-nitrophenol and oligosaccharides in p-nitrophenyl oligosaccharides. The above results reveal that, by chemical modification with diethyl pyrocarbonate and biochemical modification with an amylase inhibitor, amylase can be converted to a new exo-type enzyme which hydrolyzes only the bond between p-nitrophenol and oligosaccharides in p-nitrophenyl oligosaccharides.

Amylases↗
PubMed1989

Steady state kinetics of proton translocation catalyzed by thermophilic F0F1-ATPase reconstituted in planar bilayer membranes.

The proton-translocating ATPase of the thermophilic bacterium PS3 was reconstituted into planar phospholipid bilayers by the previously reported method (Hirata, H., Ohno, K., Sone, N., Kagawa, Y., and Hamamoto, T. (1986) J. Biol. Chem. 261, 9839-9843), and the relationship between the electric current induced by ATP and the concentration of ATP was examined. The magnitude of the electric current generated upon addition of ATP followed simple Michaelis-Menten type kinetics, and the Michaelis constant was found to be 0.14 mM under our conditions. This value is close to the values reported for F1- or F0F1-ATPase in its steady state catalytic cycle, indicating that the proton translocation is coupled to the steady state ATPase reaction. The relationship between the Km value and the membrane potential was also examined under the voltage-clamped condition, and we found that there was no apparent dependence of the Km on membrane voltage. These results together with the previous data suggest that the voltage dependence residues in some step that defines the apparent Vmax rather than Km in the reaction cycle, and proton translocation is not directly coupled to this ATP binding step.

Adenosine Triphosphate↗
PubMed1989

Effects of volatile anesthetics on cardiac calcium channels.

In order to investigate how volatile anesthetics affect cardiac calcium channels, the effects of halothane, enflurane, and isoflurane on the specific binding of [3H]-nitrendipine to bovine heart sarcolemmal membranes were studied. All three anesthetics added in liquid form inhibited [3H]-nitrendipine binding in a dose-dependent manner, and more interestingly, the order of inhibition by these volatile anesthetics roughly followed that of their anesthetic potencies. The partial pressures, calculated using the gas/water partition coefficients of halothane, enflurane, and isoflurane which inhibited [3H]-nitrendipine binding by 30% at 37 degrees C were about 1.48 x 10(-2) atm. (1.48%), 4.89 x 10(-2) atm. (4.89%) and 2.76 x 10(-2) atm. (2.76%), respectively. One mmol/l halothane altered not only the maximal binding (Bmax) from 189 f mol/mg protein to 136 f mol/mg protein, but also the dissociation constant (Kd) from 0.074 nmol/l to 0.18 nmol/l. Halothane was also added to the reaction mixture in the gaseous form with air. The partial pressure of halothane needed to bring about 30% inhibition was 0.82 x 10(-2) (0.82%), a value almost similar to that for halothane added in the liquid form. These results indicate that all three volatile anesthetics have direct effects on cardiac calcium channels, and that the magnitude of the effects depends on their anesthetic potencies.

Animals↗
PubMed1989

Somatotopic organization of forelimb representation in cervical enlargement of raccoon dorsal horn.

1. Somatosensory representation of the forelimb in the dorsal horn of spinal segments C5-T2 was examined in 13 North American raccoons anesthetized with pentobarbital sodium. Single- or multiple-unit responses to light mechanical stimulation were recorded at a total of 504 loci, which were subsequently reconstructed from stained, transverse sections. From these, dorsal view maps of forelimb representation in Rexed's laminae III and IV were synthesized. 2. There was a shifting, serial overlap of representations of different forelimb regions in both the rostrocaudal and mediolateral axes of the dorsal horn. The rostrocaudal progression of receptive fields was from preaxial forelimb to forepaw to postaxial forelimb, whereas the mediolateral progression was from the volar glabrous forepaw toward the trunk. 3. Representations of the glabrous surfaces of the digits and palm pads showed considerable overlap, with the digital representations extending more laterally, but the palmar representations extending more rostrally and caudally. One-third of all recording loci were devoted exclusively to glabrous skin representation. 4. Comparison with results of earlier studies in raccoons indicates that representation of a given digit or palm pad is more restricted in rostrocaudal extent in the dorsal horn than in the dorsal roots, and that, compared with various nuclear regions of the dorsal column-medial lemniscal system, the glabrous surfaces of the forepaw are underrepresented in the dorsal horn. 5. The results suggest that there is a dorsoventral modular organization of forelimb representation in the dorsal horn. These wedge-shaped modules from larger aggregates which represent major body subdivisions and which course sinuously in the rostrocaudal dimension.

Afferent Pathways↗