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Biomedical subjects

M Kojima

Publications and source records attributed to M Kojima.

At least 433 records · Page 24Linked to original sources
PubMed1995

Plasma endotoxin in typhoid fever.

Plasma endotoxin contents of the patients with sepsis or typhoid fever were measured by two sophisticated chromogenic limulus tests; Endospecy and Toxicolor tests. Endospecy test is the endotoxin-specific test and Toxicolor is responsible for both endotoxin and (1,3)-beta-D-glucan. Plasma was pretreated by our new PCA method which resolved the problem as to the detection of a lesser amount of plasma endotoxin when pretreated by the conventional PCA method. Although Toxicolor values have been reported to exceed more than the Endospecy value, under complicated pathophysiological situations, almost all specimens of these patients had a similar value, except in one expired septic shock case. In 18 typhoid fever cases, Salmonella typhi was isolated only from the bile in 5 cases, however endotoxemia occurred in 11 cases (61.1%). Within the first 4 days, the incidence of endotoxemia was higher (10/14, 71.4%). These results suggest that endotoxin assay seemed to be a useful tool for the diagnosis of typhoid fever.

Bacteremia↗
PubMed1994

Demonstration of derivation of rat urinary bradykinin from plasma low-molecular-weight kininogen: a study using kininogen-deficient rats.

The origin of urinary bradykinin was defined by use of plasma kininogen-deficient B/N-Katholiek rats, whose ureter urine contains very low amount of urinary kinin. The kinin level increased after the rats received an infusion of normal plasma. Furthermore, the bradykinin content in the ureter urine of these kininogen-deficient rats increased more by infusion of partially purified rat- low-molecular-weight kininogen than by that of high-molecular-weight kininogen. Urinary kallikrein activity of B/N-Katholiek rats was enzymatically identical with that of normal B/N-Kitasato rats. These results indicate that urinary bradykinin found in the ureter urine of normal rats is derived from plasma low-molecular-weight kininogen by cleavage by urinary kallikrein.

Animals↗
PubMed1994

Influence of antibodies to the hypervariable region of E2/NS1 glycoprotein on the selective replication of hepatitis C virus in chimpanzees.

A human plasma (inoculum one) containing hepatitis C virus (HCV) was passaged through eight chimpanzees in three generations. Of 10 HCV clones propagated from it, 7 were different in respect to the hypervariable region of E2/NS1 glycoprotein and they were named clones A, B, C, etc. A chimpanzee received inoculum one, and clone A accounted for 7 of the 10 clones from his acute-phase plasma (inoculum two). Five chimpanzees received inoculum two, and clone A accounted for 5 to 9 of the 10 clones each from their preacute plasma, which were pooled to make inoculum three. Of 10 HCV clones from inoculum three, 4 were A, 5 were B/B', and the remaining 1 was C. Two chimpanzees received inoculum three or its CsCl fraction, and all 40 clones from their acute-phase plasma were A. Thus, clone A in inoculum one was selected by chimpanzees during three passages. HCV virions in the three inocula were separated into free and immunoglobulin-bound forms by sucrose density fractionation. HCV virions in inocula one and two were heterogeneous in the sequence of hypervariable region and predominantly free of immunoglobulins. By contrast, inoculum three contained both free virions of predominantly A and immunoglobulin-bound virions which were heterogeneous. Antibodies to the hypervariable region were determined by enzyme immunoassays with overlapping synthetic decapeptides. Antibodies to clone A were detected in one chimpanzee who received inoculum two, and those to clones B and C in two chimpanzees including him and in inoculum three. Antibodies were not detectable in inoculum one or two or in the other chimpanzees. These results indicate that antibodies to the hypervariable region of E2/NS1 glycoprotein would be protective and contribute toward the selective replication of HCV in chimpanzees.

Adult↗
PubMed1994

Thermal stabilization of ribonuclease T1 by carboxymethylation at Glu-58 as revealed by 1H nuclear magnetic resonance spectroscopy.

Ribonuclease T1 (RNase T1) carboxymethylated at the gamma-carboxyl group of Glu-58 with iodoacetic acid is known to be completely inactive while it retains an almost full substrate-binding ability. In order to further clarify the effects of the carboxymethylation, the thermal stabilities of intact and Glu-58-carboxymethylated (CM-) RNase T1 were compared by measuring 1H NMR spectra at various temperatures. The transition curves of unfolding were obtained by plotting, as a function of temperature, the peak areas for the alpha and delta protons of Asn-81 and Ile-90, respectively, which are well apart from each other in the three-dimensional structure of the enzyme. For each of intact and CM-RNase T1, the transition curve of the Asn-81 alpha proton was identical with that of the Ile-90 delta methyl protons, suggesting that the thermal unfolding occurred simultaneously in every part of the molecule of CM-RNase T1 as well as of intact RNase T1. The midpoint of unfolding was 52 degrees C for intact RNase T1, and was increased by 9 degrees C upon carboxymethylation at Glu-58. This marked stabilization by carboxymethylation is thought to be due to formation of a salt bridge between the introduced carboxymethyl group and the neighboring guanidium group of Arg-77.

Enzyme Stability↗
PubMed1994

Genomic structure of human adrenomedullin gene.

Adrenomedullin (AM) is a potent hypotensive peptide recently discovered from human pheochromocytoma tissue by its stimulating activity of platelet cAMP production. In this study, we have isolated the gene for human AM from a human genomic library and determined its structure. The genomic DNA of human AM consists of 4 exons and 3 introns, and the 5' flanking region contains TATA, CAAT and GC boxes. There are also multiple binding sites for activator protein-2 (AP-2) and a cAMP-regulated enhancer element. Southern blot analyses revealed that the AM gene is situated in a single locus of chromosome 11. These indicate that the human AM gene has components for its functional expression and that the expression may be subject to the activity of protein kinase C and the feedback from cAMP level.

Adrenal Gland Neoplasms↗
PubMed1994

Cloning and characterization of a novel natriuretic peptide in frog (Rana catesbeiana).

C-type natriuretic peptide (CNP) is one of three members of the natriuretic peptide family. In the course of cloning frog CNP precursor cDNA, we found cDNA clones encoding a novel natriuretic peptide precursor. This novel natriuretic peptide precursor is a 118-residue peptide, carrying a 22-residue signal peptide at the N terminus and a 17-residue ring structure characteristic of the natriuretic peptide family at the C terminus. The precursor is highly homologous to mammalian CNP precursors. Its C-terminal Cys codon is directly followed by a termination codon. This feature is characteristic of CNP precursor cDNAs. The cGMP-stimulating activity of the novel natriuretic peptide was at the same level with those of frog CNP and mammalian CNPs, when rat CNP receptor was used in the cGMP assay system. Thus, this novel natriuretic peptide is structurally and functionally a member of the C-type natriuretic peptide. We designated the peptide as frog CNP II, and the previously described CNP as frog CNP I. By Northern blot analysis, expression of this novel CNP mRNA was found in brain, heart, lung, and stomach. On the other hand, frog CNP mRNA was mainly expressed in brain, where mammalian CNP mRNA is exclusively expressed. The distribution of the two frog CNPs suggests a complex system for regulating electrolyte and water balance in frog.

Amino Acid Sequence↗
PubMed1994

Hepatitis C virus infection in spouses of patients with type C chronic liver disease.

OBJECTIVE: Survey for markers of hepatitis C virus (HCV) infection in spouses of patients with HCV-related chronic liver disease. DESIGN: Cross-sectional clinical, serologic, and molecular biological study of spouses of patients with HCV viremia and chronic liver disease. SETTING: University and city hospitals. PARTICIPANTS: Spouses (52 men and 102 women; mean age, 56 +/- 11 years) of 154 patients with HCV viremia (102 men and 52 women; mean age, 58 +/- 10 years), of whom 66 had chronic hepatitis, 49 had liver cirrhosis, and 39 had primary hepatocellular carcinoma. METHODS: Tests for HCV-associated antibodies were done using a second-generation enzyme immunoassay and immunoassays with synthetic oligopeptides deduced from the HCV core gene. Hepatitis C virus RNA was detected by polymerase chain reaction with primers deduced from the 5'-noncoding region and HCV genotypes by reaction with type-specific primers deduced from the HCV core gene. RESULTS: Hepatitis C virus-associated antibodies were detected in 42 (27%) spouses, of whom 25 were also positive for HCV RNA. Of 112 (73%) spouses without detectable antibodies, 2 had chronic liver disease. The development of markers of HCV infection in spouses increased with the duration of marriage, ranging from 1 to 60 years (30 +/- 11 years). CONCLUSIONS: Spouses of patients with HCV viremia and chronic liver disease have an increased risk for acquiring HCV, which is proportional to the duration of marriage. They should be followed routinely for markers of HCV infection and liver disease.

Aged↗
PubMed1994

DNA adduct formation of hepatocarcinogenic aromatic amines in rat liver: effect of cytochrome P450 inducers.

F344 rats were treated with an i.p. injection of 2-amino-6- methyldipyrido[1,2-a:3',2'-d]imidazole (Glu P-1) or 3-methoxy-4-aminoazobenzene (3-MeO-AAB) and examined for the formation of the DNA adduct in the liver. To examine the effect of pretreatment with a cytochrome P450 (CYP) inducer on the formation of DNA adduct, these rats were pretreated with 3-methylcholanthrene (MC; CYP1A1/1A2 inducer) or phenobarbital (PB; CYP2B inducer). Administration of Glu P-1 and 3-MeO-AAB gave 2 and 5 adducts, respectively, as determined by 32P-postlabeling assay. By Glu P-1 administration, pretreatment of rats with MC, but not with PB, increased the total amount of DNA adducts including 3 new adducts as minor products. In contrast, pretreatment of rats with PB increased the total amount of DNA adducts derived by 3-MeO-AAB. The increase of aromatic amine DNA adducts by pretreatment with a CYP inducer was proportional to the activity of induced CYP isozyme(s) responsible for the mutagenic activation of each aromatic amine.

Animals↗
PubMed1994

Nerve growth factor induces trkA mRNA expression in cultured basal forebrain cholinergic neurons from 17-day fetal rats.

We first examined the basal forebrain tissues for developmental changes in expression of the high-affinity NGF receptor (trkA) gene. Our reverse transcriptase polymerase chain reaction (RT-PCR) analysis showed that trkA mRNA is present in those tissues of postnatal rats, but not in those of fetal rats. Then we determined the effect of NGF on trkA gene expression in serum-free cultures of basal forebrain neurons from 17-day fetal rats. NGF was found to induce trkA mRNA 36 h after the addition of NGF, while no trkA mRNA was detected in the absence of NGF.

Animals↗
PubMed1994

Ryanodine-induced contraction in femoral artery from spontaneously hypertensive rats.

The mechanisms of ryanodine-induced contractions were studied in strips of femoral arteries from spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY). Ryanodine (30 nM to 30 microM) alone contracted arterial strips in a dose-dependent manner. The maximum contraction in SHR was about 5 times greater than that in WKY. SHR strips had about a 30 times lower threshold than WKY strips. Pretreatment with ryanodine caused a more potent dose-dependent inhibition of 10 mM caffeine-induced contractions in SHR than in WKY. Ryanodine (10 microM) failed to contract SHR strips in a CaCl2-free solution, whereas caffeine induced a transient contraction in the solution. Under the conditions that the sarcoplasmic reticulum was depleted of Ca2+ by exposure of the strips to the CaCl2-free solution, ryanodine caused a contraction in the presence of extracellular Ca2+. Verapamil (1 nM) to 1 microM) relaxed the strips precontracted with ryanodine in a dose-dependent manner. In WKY strips exposed to a 15 mM K+ solution, ryanodine-induced contractions were potentiated and were not different from those of SHR strips in a normal K+ (5.9 mM) solution. These results suggest that ryanodine contracts rat femoral arteries by promoting Ca2+ influx through voltage-dependent Ca2+ channels, and that the ability of ryanodine to contract the arteries may depend on the state of the Ca2+ channels.

Animals↗
PubMed1994

Complete amino acid sequence of porcine adrenomedullin and cloning of cDNA encoding its precursor.

Porcine adrenomedullin was isolated from adrenal medulla extract and its amino acid sequence was determined. The peptide is identical to human adrenomedullin with a single replacement of Gly for Asn at position 40. The cDNA clone encoding the porcine adrenomedullin precursor was isolated and sequenced. The precursor for adrenomedullin (preproadrenomedullin) is 188 amino acids in length, including the adrenomedullin sequence, followed by a glycine (the amide donor). In addition to adrenomedullin, proadrenomedullin (proAM) contains a candidate for a unique 20-residue peptide, proAM-N20, whose carboxy-terminus may be amidated. By RNA blot analysis, porcine adrenomedullin mRNA was found to be highly expressed in several porcine tissues including lung and kidney as well as adrenal medulla.

Adrenal Medulla↗
PubMed1994

Percutaneous transgastric intestinal decompression: the management of malignant bowel obstruction without nasal intubation.

We inserted a long intestinal tube via the percutaneous transgastric route in three patients with an inoperable malignant bowel obstruction. The percutaneous endoscopic gastrostomy technique facilitated this method. The main purpose of our procedure is to achieve direct intestinal decompression without nasal intubation, which is not always possible by venting gastrostomy alone. Palliative intestinal decompression proved to be effective in all patients. This alternative therapeutic strategy for managing bowel obstruction in terminal cancer patients is herein presented.

Cecal Neoplasms↗
PubMed1994

Sensitisation of human ovarian carcinoma cells to cis-diamminedichloroplatinum (II) by amphotericin B in vitro and in vivo.

Human ovarian carcinoma cells (HRA) were sensitised to cis-diamminedichloroplatinum (II) (CDDP) 2.7-, 5.5- and 12.1-fold by treatment with amphotericin B (AMB) at concentrations of 2.1, 5.4 and 10.8 microM, respectively. Moreover, intracellular accumulation of platinum after a 2-h exposure to CDDP was increased significantly with AMB treatment. We prepared HRA cell-inoculated nude mice as an experimental therapeutic model for human advanced ovarian carcinoma. Ascites was evident after 7 to 9 days of intra-peritoneal (i.p.) inoculation of HRA cells, and mice died due to intra-abdominal carcinomatosis after 11 to 14 days [mean survival time (MST): 12.4 +/- 1.1 days]. Treatment with AMB (2.0 mg/kg) alone 4 days after inoculation increased MST by only 1.4 days. Simultaneous treatment with CDDP (1.0 to 2.0 mg/kg) and AMB (0.5 to 2.0 mg/kg) produced a significant increase in MST compared to treatment with CDDP alone. Maximal MST (30.1 days) was observed by treatment with 2.0 mg/kg CDDP plus 2.0 mg/kg AMB, whereas MST with 2.0 mg/kg CDDP alone was 16.4 days. A further drug accumulation study demonstrated that platinum accumulation in tumour tissues in nude mice treated with CDDP and AMB increased significantly compared to treatment with CDDP alone. These results indicate that intraperitoneal combination chemotherapy with CDDP and AMB is effective in an experimental animal model of advanced ovarian carcinoma.

Amphotericin B↗
PubMed1994

In vitro effect of KCA-098, a derivative of coumestrol, on bone resorption of fetal rat femurs.

The effects of 3,9-bis(N,N-dimethylcarbamoyloxy)-5H-benzofuro[3,2-c]quinoli ne-6-one (KCA-098), a derivative of coumestrol, on bone resorption was studied in organ cultures of 20-day fetal rat femora. KCA-098 increased the length, dry weight, and calcium and phosphorus contents of parathyroid hormone (PTH)-treated fetal rat femur. As PTH significantly reduced the calcium and phosphorus contents of the femora, probably by stimulating bone resorption, KCA-098 seems to inhibit bone resorption. In fact, KCA-098 inhibited the PTH-induced release of 45Ca from pre-labeled fetal rat femora into the medium in organ culture. Coumestrol also inhibited the release of 45Ca from bone into the medium. However, KCA-098 did not increase the uterine weight of ovariectomized rats, whereas coumestrol did so. Thus KCA-098 is a unique, new inhibitor of bone resorption that has no estrogenic activity.

Animals↗
PubMed1994

The entire nucleotide sequence and classification of a hepatitis C virus isolate of a novel genotype from an Indonesian patient with chronic liver disease.

Three hepatitis C virus (HCV) isolates were obtained from patients with chronic liver diseases in Indonesia which were not classifiable into any of the genotypes I/1a, II/1b, III/2a, IV/2b or V/3a reported previously. The entire nucleotide sequence was determined for one HCV isolate (HC-G9); the remaining two isolates were of the same genotype based on a > 95% similarity within their partial sequences spanning 2927 nucleotides (nt). The HC-G9 genome consisted of 9440 nt including the 5' untranslated region of 341 nt, an open reading frame of 9033 nt coding for a polyprotein of 3011 amino acids and the 3' untranslated region of 66 nt (U stretch of 17 to 47 nt at the extreme 3' terminus excluded). It differed by 20 to 33% in nucleotide sequence from any of 14 HCV genomes of genotypes I/1a to IV/2b whose full-length sequences are known. By the unweighted pair-group method with arithmetic mean, HC-G9 was on a major branch (group 1) of the phylogenetic tree of HCV to which genotypes I/1a and II/1b belong. It is proposed, therefore, that the novel genotype for HC-G9 should be called 1c. A method was developed to identify genotype 1c by PCR with a primer deduced from the core gene that was specific to it. Since genotype 1c was detected in seven (15%) of 48 HCV RNA samples from Indonesian patients with chronic liver disease, but not in any of 1097 from other districts of the world, it appears to have evolved and remained in Indonesia. In addition to its epidemiological importance, the association of genotype 1c HCV with the severity of liver disease and its response to interferons deserve to be evaluated.

Amino Acid Sequence↗
PubMed1994

Acute urticaria: history and natural course of 50 cases.

Fifty patients with acute urticaria who visited within a week after the onset were interviewed and the history around the onset of urticaria was carefully taken. It was known that the majority of the patients had experienced some symptoms suggestive of infection. The patients were followed up for a year to determine the last efflorescence. It was disclosed that 43 cases were cured within two weeks and 5 other cases were cured between 2 weeks and 3 months. The remaining 2 cases persisted over a year. These results seem to suggest that urticaria is an immunologically erroneous reaction to foreign body innoculation, a large majority of which is acute infection.

Acute Disease↗
PubMed1994

Potentiation of cis-diammine(1,1-cyclobutanedicarboxylato)platinum(II) by amphotericin B in BALB/c nude mice bearing human ovarian carcinoma cells.

Human ovarian carcinoma cells (HRA) were sensitized to cis-diammine(1,1-cyclobutanedicarboxylato)platinum(II) (CBDCA) 1.2-, 2.1- and 3.4-fold by treatment with amphotericin B (AMB) at concentrations of 2.1, 5.4, and 10.8 microM, respectively. Moreover, the intracellular accumulation of platinum after 2-h exposure to CBDCA was increased significantly by AMB treatment. For estimating the enhancing effect of AMB on CBDCA cytotoxicity in vivo, we prepared HRA cell-inoculated nude mice. Ascites was evident 7 to 9 days after intraperitoneal (i.p.) inoculation of HRA cells, and the mice died of intraabdominal carcinomatosis 11 to 14 days (mean survival time (MST): 12.0 +/- 1.0 days) after inoculation. Treatment with AMB (2.0 mg/kg) alone increased the MST by only 1.2 days. Simultaneous treatment with CBDCA (12 or 15 mg/kg) and AMB (0.5 to 2.0 mg/kg) produced a significant increase in MST compared to treatment with CBDCA alone. Maximal MST (38.5 days) was obtained by treatment with 15 mg/kg CBDCA plus 2.0 mg/kg AMB, whereas the MST with 15 mg/kg CBDCA alone was 15.8 days. A drug accumulation study demonstrated that platinum accumulation in tumor tissues after i.p. treatment with CBDCA and AMB in tumor-bearing nude mice was increased significantly compared to treatment with CBDCA alone. These findings indicate that intraperitoneal combination chemotherapy with CBDCA and AMB is useful in nude mice with advanced ovarian carcinoma.

Amphotericin B↗