Biomedical subjects

I Kato

Publications and source records attributed to I Kato.

At least 397 records · Page 22Linked to original sources

PubMed1992

Exposure to hepatitis B virus in the general population of Hisayama, Japan: significance of isolated antibody to hepatitis B surface antigen in general population.

Cross-sectional survey on the prevalence of hepatitis B serological markers was performed in 2,411 residents who accounted for 74.4% of the population aged 40 and over and living in Hisayama Town, Japan, in 1983. Overall prevalences were 40.7% for both anti-HBs and anti-HBc, 6.1% for isolated anti-HBs and 5.4% for isolated anti-HBc. The condition with isolated anti-HBs was different from those with isolated anti-HBc and both anti-HBc and anti-HBs as follows. The titer of anti-HBs in isolated anti-HBs positive samples was significantly lower than that in both anti-HBs and anti-HBc positive ones (46.2 +/- 5.4 vs. 83.2 +/- 2.8, mean +/- SE, p less than 0.001). The presence of isolated anti-HBs was neither significantly more frequent in males nor related to the risk of liver damages in contrast with that of anti-HBc with or without anti-HBs. These findings suggest that isolated anti-HBs pattern with the absence of anti-HBc in general population was not due to prior HBV infection, but due to natural immunization with HBsAg.

Adult↗

PubMed1992

Prevalences of hepatitis B surface antigen carriers and liver damages in the general population of Hisayama, Japan.

The prevalences of hepatitis B surface antigen (HBsAg) carriers and liver damages were studied in 2,411 residents aged 40 and over and living in Hisayama, Japan in 1983. Hepatitis B virus (HBV) associated markers were all measured by radioimmunoassay. HBsAg carriers were found in 2.3 per cent of the residents. Hepatitis B e antigen and antibody to hepatitis B e antigen were positive in 8.9 per cent and 80.4 per cent, respectively, of HBsAg carriers. The prevalences of liver damages in HBsAg carriers were compared with 1095 who had none of HBV markers (neither anti-HBc nor anti-HBs). The prevalences of abnormal aminotransferase level in sera were not different between HBsAg carriers and those who had none of HBV markers. A history of jaundice and/or hepatitis was evident in 32.3 per cent of male carriers and 24.0 per cent of female ones, being significantly more than those without HBV markers (13.1 per cent and 5.8 per cent, p less than 0.05 and p less than 0.005, respectively). These results indicate that, among HBsAg carriers aged 40 and over, few have active clinical signs of hepatitis, although about 20 per cent of them have histories of symptomatic hepatitis due to hepatitis B.

Adult↗

PubMed1992

[A case of diastematomyelia with meningomyelocele].

A case of diastematomyelia with meningomyelocele is presented here. The patient was a newly born infant with a soft tumor in the lumbo-sacral region. The lower extremities were not paretic, but anal reflex was negative. A plain X-ray and a CT scan of the spine showed a bone spur at L3, 4. An MRI showed a longitudinal slit in the spinal conus. The removal of the septum and repair of the cele was carried out. The operative view showed a bony septum which divided the spinal conus into two parts and nerves had spread out on the cele wall. After removal of the septum, the tethered cord was released. The postoperative condition remained stable. The reason for the occurrence of a combined case of diastematomyelia with meningomyelocele is not clear. We presume that abnormality of the mesoderm at the embryonic stage may have an effect on this sort of disorder.

Humans↗

PubMed1992

Receptor agonists induce myosin phosphorylation-dependent and phosphorylation-independent contractions in vascular smooth muscle.

In isolated rat aorta, 72.7 mM KCI, 10 microM prostaglandin F2 alpha, 30 nM endothelin-1 and 1 microM norepinephrine increased muscle tension, cytosolic Ca++ concentration ([Ca++]i) and 20 kDa myosin light chain (MLC) phosphorylation. The levels of contractile tension and MLC phosphorylation at a given [Ca++]i were greatest in the presence of endothelin-1 followed by prostaglandin F2 alpha greater than norepinephrine greater than high K+. Verapamil inhibited the high K(+)-induced increments to their respective resting levels. Verapamil also almost completely inhibited the receptor agonist-induced increments in [Ca++]i and MLC phosphorylation, although a part of the contraction was not inhibited. Ethylene glycol bis(beta-aminoethyl ether)-N,N'-tetraacetic acid further decreased [Ca++]i and muscle tension, suggesting that a part of the contraction is regulated by [Ca++]i below a resting level. Receptor agonists induced sustained contraction in the absence of external Ca++ which was not followed by the increase in [Ca++]i or MLC phosphorylation. This contraction was followed by the increments in shortening velocity and stiffness. In the rabbit mesenteric artery permeabilized with Staphylococcus aureus, alpha-toxin, norepinephrine and endothelin-1 shifted the Ca(++)-tension curve to the left in the presence of GTP. From these results, it is suggested that high K(+)-induced sustained contraction of vascular smooth muscle is attributable to an increase in [Ca++]i followed by an increase in MLC phosphorylation. In addition to this fundamental mechanism, receptor agonists increase Ca+ sensitivity of MLC phosphorylation when [Ca++]i is higher than resting level resulting in a greater contraction than that induced by high K+ for a given increase in [Ca++]i.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1992

Geographical aspects of bcl-2 gene involvement in Japanese patients with non-Hodgkin's B-cell lymphomas.

Using three separate bcl-2 probes, we examined involvement of the bcl-2 gene in Japanese patients with non-Hodgkin's B-cell lymphomas. Of 52 patients with follicular lymphoma (FL), 24 had rearrangements. In a group of 50 patients with diffuse lymphoma, three of 32 patients with diffuse large cell lymphoma had rearrangements. The frequency of rearrangements in each of these groups, as detected by both major and minor breakpoint cluster region probes, was compatible with that found in other Far Eastern studies. However, the difference in frequency between the groups studied in the Far East and the West was significant, and these two geographically distinct populations also displayed a difference in the breakpoint distribution. In the immunophenotype study of 33 patients with FL, the expression of CD10 antigen correlated with bcl-2 involvement, whereas none of the other B markers emerged as parameters to distinguish between the two lymphoma groups; those with, and without, the rearrangements.

Humans↗

PubMed1992

Assay of urinary free fucose by fluorescence labeling and high-performance liquid chromatography.

The concentrations of free fucose and other sugars in urine of cancer patients and healthy subjects were analyzed by high-performance liquid chromatography. After the urine samples were dried, we coupled the sugars in the residue with 2-aminopyridine to be detected as fluorescent derivatives. We then analyzed the pyridylamino derivatives of the sugars with an anion-exchange column and borate buffer. The difference between cancer patients and healthy subjects for the mean concentrations of fucose corrected for creatinine was significant (P less than 0.001). We checked the relationship between the concentrations of other sugars and the presence of cancer. This method is highly sensitive, and neither a cleanup procedure before labeling nor purification before injection into the column is needed. Not only fucose but also other sugars can be detected simultaneously, so this method should be useful for studying any changes in sugars in urine in various diseases.

Adult↗

PubMed1992

[The intraocular pressure lowering effects of UF-021, a novel prostaglandin related compound, in animals].

The ophthalmic solution of UF-021, a novel prostaglandin (PG) related compound, was investigated for its intraocular pressure (IOP) reducing activity and local ocular side effects in different species of animals. UF-021 ophthalmic solution (0.03 to 0.24%), when topically applied to the eyes of rabbits, caused dose-dependent IOP reduction (2.8 to 5.2 mmHg), without transient IOP rise. Both in cats and monkeys, UF-021 ophthalmic solution (0.12%) elicited rapid, significant IOP reduction (ca. 9 mmHg and 2 mmHg, respectively), without any controversial, local ocular side effects being revealed. On the other hand, PGE2, PGF2 alpha-isopropyl ester all brought about marked increases in IOP prior to development of their IOP reducing activities. In addition, these primary PGs showed intense local ocular irritation, which presented a striking contrast with UF-021. Enhancement of IOP reducing activity, coupled with freedom from any significant ocular side effects, as described above, suggests that UF-021 ophthalmic solution could be promising as a new anti-glaucoma agent.

Animals↗

PubMed1991

Nonradioactive labeling with chemically modified cytosine tails by the polymerase chain reaction.

We developed a modified nonradioactive method for the detection of DNA. This method makes use of the polymerase chain reaction for preparation of probes; that is, a DNA fragment inserted in the polylinker region of an M13 or pUC vector is amplified with primers that have a modified cytosine tail at the 5' terminus (C-tailed primers). By this method, large amounts of labeled probes can be obtained easily. After hybridization, modified cytosine tails can be detected immunologically. DNA labeled by this method could be used in plaque hybridization. We could detect 0.05 pg of dot-blotted labeled DNA in 30 min with an enzyme-catalyzed chemiluminescence reaction.

Base Sequence↗

PubMed1991

Nucleotide sequence of leukocidin S-component gene (lukS) from methicillin resistant Staphylococcus aureus.

The nucleotide sequence of lukS gene encoding S-component of Staphylococcal leukocidin from methicillin resistant Staphylococcus aureus (MRSA) was determined. The structural gene of lukS consisted of 857 base pairs. An open reading frame that could encode a 35,556 dalton polypeptide consisting of 315 amino acids was assigned. The molecular size of the polypeptide predicted from the amino acid composition was close to the value of pre-matured S-component determined in DNA-directed transcription/translation system. Inspection of the amino acid sequence deduced from nucleotide sequence of lukS and that from S-component of leukocidin clarified that pre-matured S-component contains a typical signal sequence at the NH2 terminus. The amino acid sequence of predicted matured S-component correlated exactly with the known N-terminal 50 amino acid sequence of S-component from MRSA and S. aureus V8. The molecular size of the predicted matured protein was also close to the value of S-component determined in both MRSA and S. aureus V8. The nucleotide sequence of the 5'-flanking region showed the presence of the consensus sequence of ribosome binding site, Pribnow box and the RNA polymerase recognition site in Escherichia coli.

Amino Acid Sequence↗

PubMed1991

Two-dimensional mapping by high-performance liquid chromatography of pyridylamino oligosaccharides from various glycosphingolipids.

A method to map sugars two-dimensionally for the analysis of the structures of oligosaccharides from glycosphingolipids is described. Nine neutral and ten acidic oligosaccharides were obtained from glycosphingolipids by endoglycoceramidase digestion and labelled with 2-aminopyridine. The pyridylamino oligosaccharides were clearly separated by high-performance liquid chromatography on commercially available C18-silica and amide-silica column. All compounds tested were mapped without any overlapping. The separation of the pyridylamino oligosaccharides on the C18-silica column depended on the numbers and positions of sialic acid and N-acetylhexosamine residues; on the amide-silica column, the separation depended on the total number of sugar residues.

Carbohydrate Conformation↗

PubMed1991

Sandwich enzyme immunoassay for serum integrins using monoclonal antibodies.

We produced monoclonal antibodies (mABs) against human integrins. Competitive enzyme-linked immunosorbent assay (ELISA) revealed that each mAB bound to different antigenic determinants. We then developed sandwich-type enzyme immunoassays (EIAs) to measure the concentration of fibronectin receptor (FNR) and vitronectin receptor (VNR). Serum immunoreactive integrin levels were measured using these EIAs in various liver and malignant diseases. In almost all cases of liver cirrhosis (LC) and hepatocellular carcinoma (HCC), serum integrin levels were significantly elevated, but were in the normal range in gastric, colon, lung cancer, and acute hepatitis (AH). The correlation between serum FNR and VNR levels was statistically significant in all cases of liver disease, and no correlation was observed between these integrin levels and conventional biochemical markers such as AST, ALT, and GGT. The serum integrin levels were demonstrated to be a potential diagnostic marker for hepatic fibrogenesis and carcinogenesis, and these sandwich EIAs could be useful for determination of these integrins in clinical laboratory tests.

Animals↗

PubMed1991

Helicobacter pylori infection and gastric carcinoma among Japanese Americans in Hawaii.

BACKGROUND: Helicobacter pylori are gram-negative spiral bacteria that are associated with chronic gastritis, a known precursor of gastric carcinoma. Persons at high risk for gastric carcinoma have been shown to have a high prevalence of H. pylori infection. METHODS: We studied the relation of H. pylori infection and gastric carcinoma in a cohort of Japanese American men living in Hawaii. The 5908 men were enrolled and examined from 1967 to 1970. By 1989, 109 cases of pathologically confirmed gastric carcinoma had been identified. The store serum of each patient with gastric carcinoma and of each matched control subject were tested for the presence of serum IgG antibody to H. pylori. RESULTS: Ninety-four percent of the men with gastric carcinoma and 76 percent of the matched control subjects had a positive test for H. pylori antibodies, for an odds ratio of 6.0 (95 percent confidence interval, 2.1 to 17.3). As the level of antibody to H. pylori increased, there was a progressive increase in the risk of gastric carcinoma (P for trend = 0.0009). The association was strong even for men in whom the diagnosis was made 10 or more years after the serum sample was obtained (odds ratio, 10.5; 95 percent confidence interval, 2.5 to 44.8). CONCLUSIONS: Infection with H. pylori is strongly associated with an increased risk of gastric carcinoma. However, most persons infected with H. pylori will never have gastric carcinoma. Therefore, other factors that increase the risk of gastric carcinoma among persons infected with H. pylori need to be identified.

Antibodies, Bacterial↗

PubMed1991

Frequency of the hypercalcemia-leukocytosis syndrome in oral malignancies.

There have been a number of reports over the last 15 years of patients with cancer who develop both leukocytosis and hypercalcemia, particularly in patients with cancers of the oral cavity. In this study, the authors report the frequency of hypercalcemia and leukocytosis in 225 patients with oral malignancies. Ten patients (4.4%) had hypercalcemia, 11 patients (4.9%) had leukocytosis, and five (2.2%) had both hypercalcemia and leukocytosis. The occurrence of these two distinct paraneoplastic syndromes in the same patients was greater than could have been expected from chance alone (chi-square = 45.8, P less than 0.0001). This study demonstrates that although hypercalcemia and leukocytosis are relatively uncommon in oral cancers, when they do occur they are frequently associated. To the knowledge of the authors, this is the first report in which the frequency of the association hypercalcemia and leukocytosis is studied in detail in large numbers of patients with oral cancer.

Adenocarcinoma↗

PubMed1991

Complete primary structure of human collagen alpha 1 (V) chain.

Several cDNA clones, encoding prepropeptide of human collagen alpha 1(V) chain, have been isolated. The prepropeptide (1838 amino acids length) of the alpha 1(V) chain was composed of a putative signal peptide, a large NH2-terminal noncollagenous region, a main collagenous region, and a COOH-terminal noncollagenous region. The signal peptide contained many leucine residues. The NH2-terminal noncollagenous region was much larger than those of the other collagens and had a region homologous to the COOH-terminal domain of laminin A chain, but it did not contain a cysteine-rich region that was maintained in the region of the other collagens. This region also contained probable tyrosine sulfation sites, and short collagenous sequences that were interrupted by three noncollagenous segments. The main collagenous region of the alpha 1(V) chain consisted of 338 repeats of Gly-X-Y-triplet. This region had a high degree (82%) of homology with the amino acids of the collagen alpha 1(XI) chain. The COOH-terminal noncollagenous region resembled that of the alpha 1(XI) chain, too, and 8 residues of cysteine that were important for the formation of the triple helix structure of collagens were observed. These results suggest that the alpha 1(V) chain belongs to the fibrillar collagen relative to the alpha 1(XI) chain, but codon usage of the alpha 1(V) cDNA was clearly different from those of the other fibrillar collagens including the alpha 1(XI), while it was similar to type IV collagen. This result supposes a different evolution of the alpha 1(V) gene from those of the other fibrillar collagens.

Amino Acid Sequence↗

PubMed1991

A one step sandwich enzyme immunoassay for gamma-carboxylated osteocalcin using monoclonal antibodies.

A highly sensitive, simple and reliable one-step sandwich enzyme immunoassay (EIA) for the gamma-carboxylated form of osteocalcin (Gla-OC) has been developed using a monoclonal antibody. The minimum amount of Gla-OC detected by this EIA was approximately 0.2 ng/ml when a 10 microliter aliquot of the sample was used. The serum Gla-OC level in 30 healthy subjects was 3.6 +/- 2.19 ng/ml (mean +/- SD). A significant increase was seen in patients with chronic renal failure (20.3 +/- 4.60 ng/ml), atherosclerosis (8.3 +/- 4.94 ng/ml) and osteoporosis (10.1 +/- 4.60 ng/ml). The correlation between the values obtained by the sandwich EIA and competitive RIA methods was given by the linear regression equation, y = 2.896 + 0.759 chi, for which the correlation coefficient (r) was 0.815 (n = 58). This newly developed Gla-OC specific EIA may be useful for the diagnosis of metabolic bone disease and ectopic calcification.

Animals↗

PubMed1991

Genomic organization of IgH gene compared with the expression of Bcl-2 gene in t(14;18)-positive lymphoma.

In three lymphoma cell lines carrying t(14;18), named FL-18, FL-218, and FL-318, the genomic organization of IgH gene was compared with the expression of bcl-2 gene; the t(14;18) of the FL-18 cells occurred downstream from the major breakpoint cluster region (mbr) of a bcl-2 gene, and that of the FL-218 and FL-318 cells within the mbr. The FL-318 expressed the normal-sized bcl-2 transcript of 8.5-kb mRNA having the noncoding region 3 to the mbr, which was found in the FL-18, and the FL-218 lacking the intact bcl-2 gene did not. This finding suggests that in t(14;18)-positive lymphoma having the breakpoint within the mbr, transcription of the nontranslocated bcl-2 allele is not necessarily silent. In addition, the FL-218 and FL-318 expressed aberrant bcl-2 transcripts and heterogenous IgH transcripts lacking the VH region, and the bcl-2 transcripts each comigrated with parts of the sterile IgH mRNAs. The FL-318, which did not exhibit switch recombination on either IgH allele, contained abundant amounts of l gamma mRNAs, a prerequisite for the recombination into the C gamma locus. One of the I-mRNA species comigrated with the aberrant bcl-2 transcript. The FL-18 and FL-218 lacking the I gamma mRNAs had completed switch recombination of both IgH alleles. This result raises a possibility that deregulated bcl-2 transcription caused by t(14;18) is capable of playing a role in class switch recombination of IgH gene.

DNA Probes↗

PubMed1991

Role of type III homology repeats in cell adhesive function within the cell-binding domain of fibronectin.

Recombinant fibronectin (FN) fragments and their mutant proteins were produced to elucidate the role of type III homology repeats in cell adhesive activity within the cell-binding domain of FN. Cell adhesive activity of the 11.5-kDa fragment, the cell attachment site of the cell-binding domain, was less than 0.1% that of native FN despite the presence of the Arg-Gly-Asp-Ser sequence. The activity increased as type III homology repeats were added to the N terminus of the 11.5-kDa fragment, and a 52-kDa fragment with four additional type III repeats had almost the same activity of native FN. Deletion of Arg-Gly-Asp from the fully active fragments completely abolished the cell adhesive activity. Deletion of one or two repeats from the 52-kDa fragment affected the extent of the cell adhesive activity, the degree of the effect being inversely correlated with the distance of the deletion from the type III repeat containing Arg-Gly-Asp-Ser. Rearrangement of type III repeats caused much loss of activity. These results suggest that the number and kinds of type III repeats and their correct alignment rather than the putative synergistic site decide the extent of the specific cell adhesive activity.

Amino Acid Sequence↗

PubMed1991

Structural and functional relationships between h- and l-caldesmons.

Two different Mr forms of caldesmon as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (Mr values in the range of 120,000-150,000, h-caldesmon and 70,000-80,000, l-caldesmon) have been already identified. h-Caldesmon is predominantly expressed in smooth muscle cells, whereas l-caldesmon widely distributes in non-muscle cells. Most recently, the molecular cloning of h-caldesmon has been reported (Hayashi, K., Kanda, K., Kimizuka, F., Kato, I., and Sobue, K. (1989) Biochem. Biophys. Res. Commun. 164, 503-511; Bryan, J., Imai, M., Lee, R., Moore, P., Cook, R. G., and Lin, W-G. (1989) J. Biol. Chem. 264, 13873-13879). The calculated Mr of this protein from its primary structure is 88,743. Here, the nucleotide and deduced amino acid sequences of l-caldesmon have been determined by cloning and sequencing the cDNA from chick brain and compared with those of h-caldesmon. The l-caldesmon cDNA encodes a sequence of 517 amino acids with the calculated Mr of 58,844. Two isoforms of caldesmon conserve the completely identical sequences in the NH2- and COOH-terminal domains except for the insertion of Ala-508 in l-caldesmon. Interestingly, the central repeating sequence of h-caldesmon (residues 201-447) is deleted in the l-caldesmon molecule. The short NH2-terminals of two caldesmons individually show the unique sequences. The results of Northern and Southern blot analyses suggest that two mRNAs (4.8 and 4.1 kilo-bases) coding for caldesmon isoforms may be generated from a single gene by alternative splicing. Using a series of truncated caldesmons expressed in Escherichia coli, the common calmodulin-, tropomyosin-, and actin-binding sites and the minimum regulatory domains, which are involved in the Ca2(+)-dependent regulation of actin-myosin interaction, have been identified within the limited consensus sequences (residues 381-433 for l-caldesmon and residues 636-688 for h-caldesmon).

Amino Acid Sequence↗