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Biomedical subjects

H Kohno

Publications and source records attributed to H Kohno.

At least 199 records · Page 11Linked to original sources
PubMed1995

[Comparison of granisetron alone and granisetron plus dexamethasone or hydroxyzine hydrochloride for the prevention of nausea and vomiting during chemotherapy including cisplatin].

The comparative study among granisetron alone and granisetron combined with hydroxyzine hydrochloride or dexamethasone was undertaken for the prevention of nausea and vomiting during chemotherapy including cisplatin in patients with advanced head and neck carcinomas. The results indicated that the combination antiemetic therapies were more effective than granisetron alone for acute nausea and vomiting, whereas a significant difference was not observed among these three groups in the acute adverse effects. Otherwhile, there were statistically significant improvements in the prevention of delayed nausea and vomiting for patients receiving granisetron combined with the other antiemetic drugs, especially the combination antiemetic therapy with dexamethasone. These results confirm the antiemetic activity of granisetron in acute nausea and vomiting induced by cisplatin and show that it has an additive effect in combination with dexamethasone.

Adult↗
PubMed1995

Combined drug therapy with diltiazem, dextran, and hydrocortisone (DDH therapy) for late cerebral vasospasm after aneurysmal subarachnoid hemorrhage: assessment of efficacy and safety in an open clinical study.

Late cerebral vasospasm after subarachnoid hemorrhage (SAH) is a disastrous phenomenon for the patients and a definite treatment has not been established. We studied 48 consecutive patients receiving high-dose diltiazem (5 micrograms/kg/min) injection combined with dextran and hydrocortisone to late cerebral vasospasm after aneurysmal subarachnoid hemorrhage (SAH). All but 2 patients underwent surgery within 72 hours after SAH. Diltiazem was continuously given via a central venous line for up to 2 weeks in conjunction with simple cisternal drainage. 5% of dextran solution (500 ml/day) was infused for 7-10 days. Hydrocortisone was given 1,600 mg on the first day, then the dose was gradually decreased over 14 days. Symptomatic vasospasm (SVS) occurred in 5 patients (10.4%), 4 patients recovered, but 1 had severe neurological deficit. A low density area on CT-scan was observed in 2 patients. Thirty patients (62.5%) had good recovery, 10 patients (20.8%) had moderate disability, 3 (6.3%) had severe disability and 3 (6.3%) had vegetative survival. Two patients died of the initial brain damage. There were no severely hypotensive side effects. However, 3 patients showed atrioventricular blockage on electrocardiogram. These side effects subsided after the dose of the drug was decreased or administration was stopped altogether. These findings show that high-dose calcium antagonist diltiazem therapy combined with dextran and hydrocortisone injection is safe and effective for prevention of late cerebral symptomatic vasospasm after SAH.

Adult↗
PubMed1995

Physical activity and immune senescence in men.

A cross-sectional survey examined whether habitual endurance exercisers retained a higher level of T cell function than sedentary individuals in old age. Subjects, all male, comprised 17 elderly runners, 16 young, and 19 elderly controls (mean ages +/- SD: 63.8 +/- 3.3, 23.6 +/- 1.6, and 65.8 +/- 3.5 yr, respectively), whose resting blood samples served for the immunological tests. Compared with the young subjects, both elderly groups had lower circulating CD3+ and CD8+ cell-counts (P = 0.029, P = 0.001, respectively), with a trend to a higher CD4/CD8 ratio, but higher percentages of activated CD3+, and "memory" CD4+ and CD8+ cells (all, P < 0.0001). Proliferative responses to phytohemagglutinin, pokeweed mitogen, and alloantigens were markedly reduced in the elderly (P < 0.001, and P = 0.024, respectively). IL-2 production tended to be decreased in the elderly sedentary subjects. However, natural killer cell activity and other cytokine production remained unchanged in the elderly sedentary subjects. Comparison between the active and sedentary elderly groups showed no differences in circulating counts of immunocompetent cells. However, the active elderly subjects demonstrated significantly greater proliferative responses to phytohemagglutinin ( P = 0.016) and to pokeweed mitogen (P = 0.011), and higher rates of IL-2 (P = 0.021), IFN-gamma (P = 0.015) and IL-4 production (P = 0.012). These results suggest that endurance training in later life is associated with a lesser age-related decline in certain aspects of circulating T cell function and related cytokine production.

Age Factors↗
PubMed1994

Identification as beta-adducin of a protein interacting with rabphilin-3A in the presence of Ca2+ and phosphatidylserine.

Rabphilin-3A is a putative target protein for Rab3A small GTP-binding protein implicated in neurotransmitter release. We have previously identified a Rabphilin-3A-interacting protein with a Mr of about 115 kDa in bovine brain. We have attempted here to purify this protein and to determine its primary structure. Amino acid sequence analysis has revealed that this protein is a bovine counterpart of human beta-adducin which is known to be a good substrate for protein kinase C. The Rabphilin-3A-interacting protein also binds to protein kinase C in the presence of Ca2+ and phosphatidylserine. These results indicate that Rabphilin-3A binds to beta-adducin in the presence of Ca2+ and phosphatidylserine.

Adaptor Proteins, Signal Transducing↗
PubMed1994

Site-directed mutagenesis of human ferrochelatase: identification of histidine-263 as a binding site for metal ions.

In nature, ferrochelatase catalyzes the insertion of ferrous ion into the porphyrin macrocycle of protoporphyrin IX to exclude two protons to form protoheme IX: other porphyrin substrates, including mesoporphyrin IX may be used in vitro. Based on the deduced amino-acid sequences, one histidine residue (H263 of human enzyme) is conserved among all ferrochelatases cloned from human to bacterial cells, and three histidine residues (H157, H341 and H388 of human enzyme) are conserved among eukaryotic ferrochelatases; no cysteine residue is conserved. To attempt to clarify the binding site of ferrous ion, we converted four highly conserved histidine residues in human ferrochelatase to alanine, using site-directed mutagenesis. The mutant enzymes were expressed in Escherichia coli, and iron- and zinc-chelating activities were examined. Mutants H157A and H388A lost most of their activities and concomitantly the enzyme became susceptible to proteolytic degradation. Kinetic studies with the residual activities showed no significant change of Km values for metal ions or for mesoporphyrin IX. Mutation at H341 did not alter the enzyme activities. Iron- and zinc-chelating activities of mutant H263A were reduced to 30% and 21% of the activities of the wild type, respectively. Moreover, this mutation resulted in 18- and 3.4-fold increases in Km values toward ferrous and zinc ions, respectively, while the Km value for mesoporphyrin remained unchanged. These results indicate that the binding site for metal ions in ferrochelatase is distinct from that for the porphyrin, and suggest that histidine-263 contributes significantly to the binding of metal ions. Maintenance of the structure of the protein molecule may involve functions related to histidine-157 and -388.

Alanine↗
PubMed1994

Natural autoantibody against apolipoprotein A-I. Detection and characterization of the monoclonal antibody established from normal unimmunized BALB/c mice.

During the course of studying the immunogenicity of soybean lipids, we observed frequent production of the mAbs that bind to apolipoprotein A-I (apoA-I) when spleen cells from unimmunized normal BALB/c mice were employed for fusion. Of the 986 colonies from six fusions, 38 (3.9% of the total) were directed against apoA-I and 13 mAbs (IgM) were established for further analysis. The following lines of evidence indicate that this family of mAb may form a novel family of natural autoantibodies against apoA-I: 1) The mAbs were shown to bind effectively to high density lipoprotein from various species, including BALB/c mouse, and immunoblotting analyses revealed that the mAbs bound specifically to the 28-kDa protein of high density lipoprotein. 2) The 28-kDa protein was purified to homogeneity and identified as apoA-I by amino acid sequence analyses and by its cross-reactivity with a xenogenic anti-apoA-I mAb (clone A/11). 3) Differing from the xenogenic anti-apoA-I mAb, the present mAb did not bind to native apoA-I, whereas an effective binding was observed only when the apoA-I had formed a complex with neutral lipids containing polyunsaturated fatty acids such as trilinoleoylglycerol and 5-cholesten-3 beta-ol 3-linoleate. 4) Sera from unimmunized BALB/c mice had readily detectable Abs against apoA-I and the majority of the serum autoantibodies were of the IgA and IgM isotype. 5) The anti-apoA-I mAbs displayed a functional heterogeneity in their reactivity with polyanionic substances and some of the mAbs established showed an extensive cross-reaction with polyanionic substances such as ssDNA and cardiolipin.

Animals↗
PubMed1994

Overexpression in Escherichia coli, and one-step purification of the human recombinant ferrochelatase.

Ferrochelatase (EC 4.99.1.1), a mitochondrial inner membrane-bound protein, is the terminal enzyme of heme biosynthesis. The cDNA encoding the human mature ferrochelatase was placed under transcriptional control of T7 RNA polymerase in an Escherichia coli expression system. The bacteria produced large amounts of 42 kDa protein which reacted with anti-ferrochelatase antibodies. Expressed ferrochelatase exhibited iron- and zinc-chelating activities, and was found as a soluble protein. The recombinant enzyme has been purified to apparent homogeneity with a high yield, by one-step purification involving Blue-Sepharose chromatography. The purified enzyme which showed a molecular weight of about 40,000 by gel-filtration, functioned in a monomeric form. Km value for both mesoporphyrin IX and protoporphyrin IX with zinc was 12.5 microM. Km values for iron and zinc with mesoporphyrin IX were 6.7 microM and 11.8 microM, respectively. Zinc-chelating activity was markedly stimulated by palmitic acid, but iron-chelating activity remained unchanged. The above results were similar to those reported previously for mammalian ferrochelatase. The overexpression and the simple purification of a functional ferrochelatase exhibiting the same properties as natural enzyme will allow us to elucidate the mechanism of the enzyme reaction and structural changes of the mutated enzyme.

Amino Acid Sequence↗
PubMed1994

Induction of peripheral-type benzodiazepine receptors during differentiation of mouse erythroleukemia cells. A possible involvement of these receptors in heme biosynthesis.

To search for a possible role for peripheral-type benzodiazepine receptors (PBR) during erythroid differentiation, we cloned the PBR isoquinoline carboxamide-binding protein (PBR/IBP), an 18-kDa protein on PBR, from a mouse erythroleukemia (MEL) cell cDNA library. Sequence analysis revealed that PBR/IBP comprises 169 amino acid residues (M(r) 18,828), and has a high homology with PBR/IBP from other sources. The cDNA allows for the expression of active PBR/IBP, exhibiting a high affinity for isoquinoline carboxamide, [3H]PK11195, with Kd of 0.80 and 1.56 nM. RNA blot analysis revealed that treatment of MEL cells with dimethyl sulfoxide led to an increase in PBR/IBP mRNA (delta 1.0 kilobases) for up to 72 h, with a concomitant induction of mRNAs for heme biosynthetic enzymes, coproporphyrinogen oxidase and ferrochelatase. The induction of PBR/IBP mRNA was also observed in MEL cells induced with diazepam. The binding activity of [3H]PK11195 in MEL cells showed a high affinity with Kd of 0.69-2.13 nM, and increased during erythroid differentiation. The order of potency of different ligands to compete against [3H]PK11195 binding in induced MEL cells was PK11195 > protoporphyrin IX > diazepam > coproporphyrinogen III > coproporphyrin III > estazolam. In contrast to the induction of PBR/IBP in induced MEL cells, the voltage-dependent anion channel (mitochondrial porin) associated with PBR remained unchanged. These results suggest that PBR/IBP on PBR may be involved in porphyrin transport and may even be a critical factor in erythroid-specific induction of heme biosynthesis.

Amino Acid Sequence↗
PubMed1994

Molecular cloning, sequencing and expression of cDNA encoding human coproporphyrinogen oxidase.

A complete cDNA clone encoding human coproporphyrinogen (coprogen) oxidase, the sixth enzyme in the heme biosynthetic pathway, has been isolated from a human placenta cDNA library. The cDNA had an open reading frame of 1062 base pairs encoding a protein of 354 amino acid residues (M(r) 40,291). Amino acid sequencing showed that the mature enzyme consists of 323 amino acid residues (M(r) 36,842) with a putative leader peptide of 31 amino acid residues. The human enzyme showed an 86% identity to the mouse enzyme. In addition, the recombinant enzyme which did not contain leader peptide was actively expressed in Escherichia coli. The isolation and expression of cDNA for human coprogen oxidase should facilitate studies of the structure of the gene as well as characterization of molecular lesions causing hereditary coproporphyria.

Amino Acid Sequence↗
PubMed1994

Blockade of liver macrophages by gadolinium chloride reduces lethality in endotoxemic rats--analysis of mechanisms of lethality in endotoxemia.

We investigated the effects of gadolinium chloride (GdCl3.6H2O), which blocks phagocytosis by liver macrophages, on the mortality, blood tumor necrosis factor (TNF) levels, and hepatotoxicity in a lethal endotoxic shock rat model system [10 mg/kg body weight lipopolysaccharide (LPS) intravenously]. With administration of GdCl3, twice at 0.5 or 5 mg/kg, the survival rate 24 h after LPS injection was 56% and 100%, respectively, whereas the level of TNF in blood was not affected. Microscopic investigation of the liver revealed that the focal necrosis of hepatocytes under endotoxemia was completely protected by the administration of GdCl3 at 5 mg/kg. We then investigated the effects of GdCl3 on superoxide (O2-) production by isolated liver macrophages in vitro. The O2- production by liver macrophages isolated from control rats was suppressed by GdCl3 in a dose-dependent manner. GdCl3 also had a cytotoxic effect on these macrophages. The enhanced O2- production by liver macrophages isolated from sublethal endotoxemic (1 mg/kg) rats was suppressed by pretreatment with GdCl3 (5 mg/kg). It was suggested that lethality in endotoxemia cannot be explained only by the degree of increase in blood TNF levels and that the mechanism by which GdCl3 reduces mortality and hepatotoxicity in endotoxemia possibly includes suppression of superoxide production by liver macrophages.

Animals↗
PubMed1994

Monoclonal antibodies specific for 18-hydroxycortisol and their use in an enzyme immunoassay for human urinary 18-hydroxycortisol for diagnosis of primary aldosteronism.

We report the development of a monoclonal antibody-based enzyme immunoassay (EIA) specific for human urinary 18-hydroxycortisol, a biological marker of primary aldosteronism. Hybrid cell lines (hybridomas) were isolated after fusion between myeloma cells and spleen cells prepared from mice immunized with 18-hydroxycortisol conjugate. A competitive EIA suitable for the measurement of urinary 18-hydroxycortisol was developed using the mouse monoclonal antibody, KTM-41, which showed no practical cross-reaction with related endogenous steroids and synthetic steroids. This EIA meets all the requirements of routine clinical assay in terms of sensitivity (detection limit: 20 nmol/L), reproducibility (total CV: 8-15%), accuracy (recovery: 88-115%), simplicity and rapidity (< 3 h). Urinary 18-hydroxycortisol measured by the present assay was 153 +/- 119 nmol/L (mean +/- SD, range, 28-485) and 1787 +/- 1180 (range, 810-4264) in normal subjects (n = 20) and in patients with primary aldosteronism (n = 7), respectively. Clinical validation of the assay was confirmed by an appropriate decrease in urinary 18-hydroxycortisol level in patients with primary aldosteronism subsequent to adrenalectomy: 171 +/- 141 nmol/L (range, 41-466).

Animals↗
PubMed1994

Anti-estrogen activity in the yeast transcription system: estrogen receptor mediated agonist response.

The mouse estrogen receptor was expressed in yeast cells to study the mechanism of action of anti-estrogens. Tamoxifen and hydroxytamoxifen, estrogen antagonists in mammalian tissues, failed to antagonize estradiol-induced expression of a VitA2-ERE-CTC1-lacZ reporter gene construct and exhibited full agonist activity, while nafoxidine exhibited partial antagonism as well as partial agonism. ICI 164,384 is a potent anti-estrogen in both mouse and human estrogen receptor systems. Our previous studies in the mouse uterus indicated that rapid degradation of the estrogen receptor accounted for the loss of estrogen responsiveness. In yeast however, ICI 164,384 or an isomer ICI 182,780 were unable to antagonize estradiol at concentration of 200 microM. On the contrary, both ICI compounds exhibited partial agonist activity by stimulating beta-galactosidase activity to 50% that of estradiol. We examined the level of estrogen receptor in the yeast after treatment with estradiol, ICI 164,384 or vehicle by Western blot and found no ICI-induced reduction of estrogen receptor levels, but observed an increase in estrogen receptor following estradiol treatment. This indicates that the proteolytic activity responsible for degrading estrogen receptor in ICI 164,384-treated uteri or eukaryotic cells is not present in yeast. The agonist activity seen with ICI indicated that ICI-bound estrogen receptor is able to induce expression of an estrogen-responsive reporter gene. In support of this, estrogen receptor from ICI 164,384-treated yeast was able to bind an estrogen-responsive element in a gel-shift assay.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Effect of verapamil on hepatic reperfusion injury after prolonged ischemia in pigs.

This study investigated the effect of verapamil on prolonged and severe ischemic injury and elucidated the association of the calcium blocking action with cellular injury, assessing changes in hepatic calcium concentrations during ischemia and reperfusion in pigs. Hepatic ischemia was produced for 180 min by clamping both the hepatic artery and portal vein during temporary portacaval shunt performed before the induction of ischemia. Pigs were divided into two groups: the animals in the verapamil group (Group V, n = 6) received continuous administration of 0.025 mg/kg per min of verapamil intraportally for 20 min before ischemia. The control group (Group C) received nothing. A better survival rate was observed in Group V than in Group C (p < 0.01), but serum aspartate aminotransferase was higher in Group V after reperfusion (p < 0.05). There were no significant changes in hepatic calcium concentrations during ischemia in either group, but it increased immediately after reperfusion in both groups. However, no significant difference was found between the two groups. Recovery of the pyruvate/lactate ratio in Group V tended to be better after reperfusion compared to Group C (p = 0.08). These data suggest that the pre-ischemic administration of verapamil produced better survival in animals after prolonged normothermic ischemia. However, the reperfused liver suffered more severe damage in the first 6 h after reperfusion in the verapamil-treated animals. Moreover, there seemed to be very little blocking action of calcium influx. A reduced oxygen requirement may be involved in the protective action of verapamil on animal survival.

Animals↗
PubMed1994

Purification and characterization of a substrate protein for mitochondrial ATP-dependent protease in bovine adrenal cortex.

We have purified SP-22, a substrate protein for mitochondrial ATP-dependent protease in bovine adrenal cortex. Native SP-22 showed an M(r) of 350,000 +/- 20,000, and was composed of more than 10 molecules of an M(r) 21,600 subunit. Subcellular and submitochondrial fractionation of adrenocortical tissues revealed that SP-22 was localized in the mitochondrial matrix, suggesting that SP-22 is a natural substrate for ATP-dependent protease, a matrix enzyme. The concentration of SP-22 in adrenocortical mitochondrial fractions was 16 +/- 3 micrograms/mg proteins (mean +/- SD, n = 6) as determined by radioimmunoassay using specific anti-SP-22 antibody. Adrenal cortex showed the highest concentration among the 15 bovine tissues tested, followed by liver, renal cortex, adrenal medulla, heart, and renal medulla. We determined the amino acid sequence of SP-22, which is composed of 195 amino acids. Amino acid 47 was not identified by the sequencer. FAB-mass spectrometry of AA47-AA55 fragment revealed that AA47 was cysteine-sulfinic acid (Cys-SO2H). By a homology search in the NBRF-PIR data base, SP-22 was found to be 91% homologous to murine erythroleukemia cell MER-5 protein, which may have an important role in the induction of differentiation. SP-22 was also homologous to the C22 component of alkyl hydroperoxide reductase in Salmonella typhimurium, thiol-specific antioxidant in Saccharomyces cerevisiae, and some other proteins. Since a segment around AA47 was highly conserved, this residue may be important for the biochemical functions of SP-22.

ATP-Dependent Proteases↗
PubMed1994

The degrees of UVB-induced erythema and pigmentation correlate linearly and are reduced in a parallel manner by topical anti-inflammatory agents.

To examine whether it is possible to evaluate the degree of ultraviolet B (UVB)-induced inflammation by measuring the degree of hyperpigmentation, we investigated the relationship between UVB-induced erythema and the subsequent pigmentation quantitatively. At 24 h and 7 d after irradiation with erythemogenic doses of UVB to the backs of 16 Japanese subjects, the degree of induced erythema (delta erythema index) and that of pigmentation (delta melanin index) were examined by an image analytic method using a videomicroscope interfaced with a computer. The relationship between two indices was linear in each subject, and the correlation coefficient was 0.83 when evaluated using whole data. The slope of the regression line for the delta melanin index against delta erythema index tended to become steeper as non-irradiated skin color became darker (r = 0.63), suggesting that more efficient melanogenesis takes place after the same level of inflammation in the subject with darker skin. Both erythema and hyperpigmentation were suppressed significantly and in a parallel manner by corticosteroids and indomethacin applied topically immediately after UVB irradiation. These results imply that the post-inflammatory hyperpigmentation correlates closely with the severity of the prior inflammation and that chemical mediators released in the inflammatory process have considerable influence on the melanogenesis. We conclude that the measurement of UVB-induced hyperpigmentation can be utilized for the assessment of topical anti-inflammatory agents, unless these have direct actions on the tyrosinase activity of melanocytes.

Administration, Topical↗
PubMed1994

[Intraarterial chemoembolization therapy for unresectable liver cancer using plachitin particles].

Plachitin formed of both poly-N-acetyl-D-glucosamine (chitin) and cis-diamminedichloroplatinum (CDDP), was used as an arterial chemoembolization therapy against unresectable liver cancer. One gram of Plachitin contained 300 mg of CDDP. The Plachitin particle was 50-100 microns in diameter. Plachitin particles (50-100 mg) were injected via hepatic artery once or twice every week, and the total amount of 300 mg was considered one course of this therapy. The size and number of tumors were measured by computer tomography (CT). Pharmacokinetics of this drug was also assessed by serum and urine platinum (Pt) concentration. Three patients underwent the chemoembolization therapy using plachitin particles. Case 1 had multiple hepatocellular carcinomas. The tumor regression rate was 39% after two courses of this therapy. Serum alpha-fetoprotein (AFP) level decreased from 1,182 ng/ml to 300 ng/ml. Case 2 suffered from bile duct cystadenocarcinoma. After three courses of the therapy, the tumor regression rate was 84.4%. Serum carbohydrate antigen 19-9 (CA19-9) decreased from 731 U/ml to 75 U/ml. Case 3 had synchronous multiple liver metastases from sigmoid colon cancer. The tumor regression rate was 77% after one course of the therapy. Carcinoembryonic antigen (CEA) and CA19-9 decreased from 406 ng/ml to 65 ng/ml and from 4,800 U/ml to 790 ng/ml, respectively. The response rate of the 3 cases was 66.7%. The peak levels of the serum Pt concentration of three patients were 0-0.4 microgram/g throughout the therapy, but peak urine Pt concentrations were observed during one course of the therapy of three patients ranging from 0.5 microgram/g to 3.2 micrograms/g, and decreased gradually for three weeks after the first course. Adverse effects of Plachitin particles for arterial chemoembolization were epigastralgia, nausea, fever, and elevation of serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels. These adverse effects were observed in all patients, but were transient. Catheter obstruction occurred in one patient (case 2). Cholecystitis, pancreatic pseudocyst, and duodenal ulcer were noticed in case 3. No renal hypofunction was observed. Plachitin might be a useful agent for arterial chemoembolization therapy for primary and secondary liver cancer.

Aged↗