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Biomedical subjects

T Horiuchi

Publications and source records attributed to T Horiuchi.

At least 289 records · Page 16Linked to original sources
PubMed1994

Increased feline cerebral blood flow induced by dehydroevodiamine hydrochloride from Evodia rutaecarpa.

Dehydroevodiamine hydrochloride (0.1-0.3 mg/kg iv), which was isolated from the leaves of Evodia rutaecarpa, increased the cerebral blood flow recorded from the surface of the supra-sylvian gyrus in anesthetized cats. This action reached a maximum 1-4 min after injection and continued for 10 min. However, the compound had negligible effects on other cardiorespiratory functions at the doses examined. These results suggest that the compound selectively increases cerebral blood flow.

Alkaloids↗
PubMed1994

The DNA replication fork blocked at the Ter site may be an entrance for the RecBCD enzyme into duplex DNA.

In Escherichia coli, eight kinds of chromosome-derived DNA fragments (named Hot DNA) were found to exhibit homologous recombinational hotspot activity, with the following properties. (i) The Hot activities of all Hot DNAs were enhanced extensively under RNase H-defective (rnh) conditions. (ii) Seven Hot DNAs were clustered at the DNA replication terminus region on the E. coli chromosome and had Chi activities (H. Nishitani, M. Hidaka, and T. Horiuchi, Mol. Gen. Genet. 240:307-314, 1993). Hot activities of HotA, -B, and -C, the locations of which were close to three DNA replication terminus sites, the TerB, -A, and -C sites, respectively, disappeared when terminus-binding (Tau or Tus) protein was defective, thereby suggesting that their Hot activities are termination event dependent. Other Hot groups showed termination-independent Hot activities. In addition, at least HotA activity proved to be dependent on a Chi sequence, because mutational destruction of the Chi sequence on the HotA DNA fragment resulted in disappearance of the HotA activity. The HotA activity which had disappeared was reactivated by insertion of a new, properly oriented Chi sequence at the position between the HotA DNA and the TerB site. On the basis of these observations and positional and orientational relationships between the Chi and the Ter sequences, we propose a model in which the DNA replication fork blocked at the Ter site provides an entrance for the RecBCD enzyme into duplex DNA.

Bacterial Proteins↗
PubMed1994

Interleukin-4 in chronic myelomonocytic leukemia. Growth suppression of hematopoietic precursors in the chronic phase and stimulation in the acute phase.

We examined the effects of interleukin-4 (IL-4) on the growth of hematopoietic precursors from a patient with chronic myelomonocytic leukemia (CMMoL). In the chronic phase of the disease, IL-4 inhibited spontaneous colony formation by CMMoL cells in semi-solid culture. However, in the acute phase, IL-4 promoted colony formation. These effects of IL-4 were abolished completely by the addition of anti-IL-4 neutralizing antibodies. The spontaneous colony formation by CMMoL cells in both the chronic and acute phases was inhibited by the addition of anti-IL-6 antibodies. On the other hand, neither anti-IL-6, anti-granulocyte macrophage colony-stimulating factor (GM-CSF), anti-IL-1 beta nor anti-tumor necrosis factor alpha (TNF alpha) antibodies inhibited IL-4-induced colony formation by CMMoL cells in the acute phase. IL-4 suppressed the production of IL-6 by CMMoL cells in both the chronic and acute phases. These results suggest that in the present patient, IL-4 suppressed the IL-6-mediated autocrine growth of CMMoL cells in both the chronic and acute phases, but directly stimulated their growth in the acute phase.

Antibodies↗
PubMed1994

[Muscular sarcoidosis].

Sarcoidosis is a multisystem granulomatous disorder of unknown etiology presenting with bilateral hilar lymphadenopathy, pulmonary, skin, and eye lesion. Sarcoidosis involving skeletal muscle is not uncommon because non caseating granuloma have been demonstrated in as much as 50 to 80% of sarcoidosis cases. Symptomatic muscle involvement, however, is rare. Chronic and acute myopathy and palpable nodular lesions due to sarcoidosis involving skeletal muscle have been reported. Chronic myopathy is progressive muscle disease with muscle weakness and wasting. Because this syndrome is rare, its natural history and responsiveness to corticosteroid have not been defined well. We review the medical literature of previously reported cases of muscular sarcoidosis.

Female↗
PubMed1993

Complete nucleotide sequence of the 5-exo-hydroxycamphor dehydrogenase gene on the CAM plasmid of Pseudomonas putida (ATCC 17453).

We determined the complete nucleotide sequence of the first gene of Pseudomonas putida cytochrome P-450cam hydroxylase operon, camD, which encodes 5-exo-hydroxycamphor dehydrogenase. This dehydrogenase apparently consists of 361 amino acids and has a molecular mass of 38.4 kDa. Structural relationships to other zinc-containing alcohol dehydrogenases also became evident.

Alcohol Dehydrogenase↗
PubMed1993

En bloc resection for cancer of the gastric cardia without thoracotomy.

Thirty-five consecutive patients underwent en bloc resection of cardia cancer without thoracotomy. All tumors were adenocarcinoma. The operative procedure involved wide resection of the peri-hiatal diaphragm, dissection of the upper abdominal and lower mediastinal lymph nodes, and resection of the stomach including a portion of the lower thoracic esophagus without thoracotomy. The resection area of the diaphragm included not only the crural muscle as in other methods, but also the diaphragmatic tissue surrounding the esophageal hiatus. Through the enlarged hiatus, dissection of the mediastinum was possible up to the carina from the abdominal cavity. The mediastinal node stations were affected in 25% of patients whose tumor invaded to the serosa. Hypotension with or without atrial arrhythmias and pleural tears occurred during surgery in 20 patients (57%) and in 18 patients (51%), respectively. Postoperatively, hypoxia requiring reintubation developed in 7 patients (19%), pleural effusions needed tube drainage in 16 patients (46%), atelectasis in 5 patients (14%), and anastomotic leaks in 3 patients (9%). They were all successfully treated. The cumulative 5-year survival rate for 21 patients with stages I (2 patients), II (9), and III (10) diseases was 62%, whereas none of the patients with stage IV disease lived for more than 2 years after surgery. Because thoracotomy is avoided, the procedure is better tolerated by debilitated patients. We believe this technique is a reasonable and safe alternative to the left thoracotomy approach for resection of cancer of the gastric cardia.

Adenocarcinoma↗
PubMed1993

Establishment of gastric surface mucous cell lines from transgenic mice harboring temperature-sensitive simian virus 40 large T-antigen gene.

We succeeded in establishing two gastric surface mucous cell lines (designated as GSM06 and GSM10), which produce periodic acid-Schiff (PAS)- and concanavalin A (Con A)-positive glycoproteins, from a primary culture of gastric fundic mucosal cells of adult transgenic mice harboring a temperature-sensitive simian virus 40 large T-antigen gene. At the permissive temperature (33 degrees C), GSM06 and GSM10 cells grew until confluent monolayers were formed and have now been in culture for more than 9 months with regular passaging. Con A-horseradish peroxidase- and PAS-positive staining indicated that these cells retain the characteristics of gastric surface mucous cells. GSM06 cells showed temperature-sensitive growth in culture and expressed SV40 large T-antigen at the permissive temperature but not at a nonpermissive temperature (39 degrees C). In contrast, GSM10 cells showed temperature-insensitive growth and expressed T-antigen at both permissive and nonpermissive temperatures. To our knowledge, this is the first report of the establishment of gastric surface mucous cell lines from animals. These immortalized cell lines with normal characteristics may serve as good experimental models for the basic and applied biology of gastric surface mucous cells.

Animals↗
PubMed1993

Specific chromosomal sites enhancing homologous recombination in Escherichia coli mutants defective in RNase H.

To clone new replication origin(s) activated under RNase H-defective (rnh-) conditions in Escherichia coli cells, whole chromosomal DNA digested with EcoRI was to with a Kmr DNA fragment and transformed into an rnh- derivative host. From the Kmr transformants, we obtained eight kinds of plasmid-like DNA, each of which contained a specific DNA fragment, termed "Hot", derived from the E. coli genome. Seven of the Hot DNAs (HotA-G) mapped to various sites within a narrow DNA replication termination region (about 280 kb), without any particular selection. Because Hot DNA could not be transformed into a mutant strain in which the corresponding Hot region had been deleted from the chromosome, the Hot DNA, though obtained as covalently closed circular (ccc) DNA, must have arisen by excision from the host chromosome into which it had initially integrated, rather than by autonomous replication of the transformed species. While Hot DNA does not have a weak replication origin it does have a strong recombinational hotspot active in the absence of RNase H. This notion is supported by the finding that Chi activity was present on all Hot DNAs tested and no Hot-positive clone without Chi activity was obtained, with the exception of a DNA clone carrying the dif site.

Chromosomes, Bacterial↗
PubMed1993

Human complement factor B: cDNA cloning, nucleotide sequencing, phenotypic conversion by site-directed mutagenesis and expression.

A full-length cDNA clone, BHL4-1, encoding factor B was isolated from a human liver cDNA library and sequenced in its entirety. It consists of 2388 bp which include a 5'-untranslated region of 40 bp, a single open reading frame, 2292 bp in length, and a 3'-untranslated region of 56 bp followed by a poly-A tail. The deduced amino acid sequence comprises 25 residues of a putative leader peptide and 739 residues of the mature polypeptide chain of the F allele of factor B. We constructed an S allele-like Q7R mutant of BHL4-1 by site-directed mutagenesis. Both the wild-type and mutant factor B cDNA were expressed transiently in a eukaryotic system. The specific hemolytic activities of the two recombinant factor B alleles and of native B were not significantly different from each other.

Alleles↗
PubMed1993

Water transport model during CAPD: determination of parameters.

To minimize the total amount of glucose required for removing the same volume of water as a bolus, a continuous infusion of glucose during CAPD was proposed and studied. Both a computer simulation of water transport through the peritoneal membrane and in vivo assessment with rats were carried out to evaluate the feasibility of the newly proposed mathematical model in which lymphatic drainage of dialysate from the peritoneal cavity to lymphatic system was considered in addition to conventional water transport. Mass transport area coefficients (KA) of 0.041 to 0.063 ml/min/100 g body wt and 0.045 to 0.066 ml/min/100 g body wt were measured for glucose and urea during CAPD with male Wistar rats. Hydraulic conductivity of peritoneal membrane (Lc) was 7.9 x 10(-5) to 1.5 x 10(-4) ml/min/mm Hg/100 g body wt, which was calculated by a linear relationship between volume and osmotic pressure. Simulated water transport model using determined parameters indicated that the ratio of lymphatic transport to convective transport would be changeable in CAPD with glucose infusion at varying infusion rates, while up to 16% of the glucose uptake could be reduced compared with that of the common CAPD at the same dwell time.

Animals↗
PubMed1993

Compressing data volume of left ventricular cineangiograms.

In this paper a method of compressing data volume for left ventricular cineangiograms is proposed. This method enables digital-optical discs to store the cineangiograms with an equivalent recording density to that of HDTV VTR's while preserving the quality of the original image. The data volume of the cineangiograms is compressed by approximating function and storing its coefficients. With this method, each cineangiogram frame is first decomposed into three regions: the inner part, the inner wall, and the background (using a statistical method previously reported by the authors). Each region is then compressed by means of a difference operation and an adaptive approximation with smooth functions. Performance is tested on 20 cases using actual cineangiograms. The specifications were verified for a spatial resolution of 1000 TV lines, a dynamic range of 60 dB, an SNR of 40 dB [pp/rms], volume compression to 7% of the original volume, and 0.19 [second/frame] for decoding on a 1.7 MFLOPS computer.

Algorithms↗
PubMed1993

Transcription of the cam operon and camR genes in Pseudomonas putida PpG1.

In Pseudomonas putida carrying the CAM plasmid, the operon (camDCAB) encoding enzymes involved in the degradation pathway of D-camphor is negatively regulated by the CamR protein, and camR is autorepressed. S1 nuclease mapping revealed that camDCAB and camR were divergently transcribed from overlapping promoters, the transcription start sites were separated by 11 bp, and transcriptions of the cam operon (camDCAB) and camR increased about 10- and 4-fold, respectively, immediately after addition of camphor. The transcriptions of camDCAB and camR were negatively regulated through the interaction of the CamR protein with the one operator located in the overlapping promoter region. In vitro transcription experiments were performed to characterize the regulation of cam genes. The camR promoter was initiated by P. putida RNA polymerase containing sigma 70, but transcription from the camDCAB promoter by sigma 70 holoenzyme was not observed. The purified CamR protein repressed in vitro transcription from the camR promoter. This repression was suppressed by camphor. The RNA polymerase binding region of the camR promoter was identified by using DNase I footprinting. In addition, footprinting studies revealed that the CamR protein and RNA polymerase coexisted on the promoter region in a joint nonproductive complex.

Bacterial Proteins↗
PubMed1993

Evidence for autoregulation of camR, which encodes a repressor for the cytochrome P-450cam hydroxylase operon on the Pseudomonas putida CAM plasmid.

The regulatory gene camR on the CAM plasmid of Pseudomonas putida (ATCC 17453) negatively controls expression of the cytochrome P-450cam hydroxylase operon (camDCAB) for the camphor degradation pathway and is oriented in a direction opposite to that of the camDCAB operon. In this study, we examined expression of the camR gene by monitoring the beta-galactosidase activity of camR-lacZ translational fusions in P. putida camR and camR+ strains. We found that the camR gene was autogenously regulated by its own product, CamR. To search for an operator site of the camR gene, a cam repressor (CamR)-overproducing plasmid, pHAOV1, was constructed by placing the camR gene under the control of a pL promoter. The translational initiation codon of CamR was changed by site-directed mutagenesis from GTG to ATG to improve translation efficiency. Judging from sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis, the CamR protein was expressed up to about 10% of the soluble protein of CamR-overproducing Escherichia coli JM83/pHAOV1 cells. Results of DNase I footprinting assays using the cell lysate indicated that the CamR repressor covered a single region between the camR gene and the camDCAB operon. Our findings also suggest that the camR gene autogenously regulates its own expression by binding of the gene product, CamR, to the operator, which also serves as an operator of the camDCAB operon.

Base Sequence↗
PubMed1993

Immunological analysis of T cells bearing T cell receptor alpha/beta or gamma/delta in patients with granular lymphocyte proliferative disorder.

Immunological analysis of 2 cases of granular lymphocyte proliferative disorder with clonal expansion of CD3+4-8+ T cells bearing either T cell receptor alpha/beta (patient 1) or T cell receptor gamma/delta (patient 2) is reported. Significant cytotoxic activity against K562 was observed in peripheral blood mononuclear cells (PBMC) isolated from patient 2, but not in PBMC from patient 1, although the cytotoxic activity of patient 1 could be augmented following incubation with anti-CD3 monoclonal antibody (MoAb). Northern blot analysis revealed that perforin mRNA was expressed in both patients. Proliferative response to phytohemagglutinin, anti-CD3 MoAb and 12-O-tetradecanoylphorbol-13-acetate was low in PBMC from both patients compared to that from healthy controls. Cytoplasmic free calcium of PBMC from the 2 patients increased similarly to that of healthy controls after treatment with anti-CD3 MoAb.

Adult↗
PubMed1993

Mast cells are essential for the full development of silica-induced pulmonary inflammation: a study with mast cell-deficient mice.

Silicosis provides a good model for chronic interstitial pulmonary inflammation. In order to clarify the role of mast cells in the development of interstitial lung diseases, silica suspension was transnasally administered to mast cell-deficient mice (WBB6F1-W/Wv) and their mast cell-intact littermates (WBB6F1(-)+/+) as well as to normal mice (C57BL/6). Histologic examinations and analyses of bronchoalveolar lavage fluid (BALF) components indicated that silica instillation induces less severe lung lesions in mast cell-deficient mice than in mast cell-intact mice. BALF neutrophilia was prominent in mast cell-intact mice, but mast cell-deficient mice developed significantly milder BALF neutrophilia. An increase in the number of lung mast cells was observed in mast cell-intact mice. To further prove the involvement of mast cells, bone marrow-derived cultured mast cells from +/+ mice were adoptively transferred to mast cell-deficient mice. These mast cell-reconstituted mice developed more severe pulmonary lesions than did the mast cell-deficient mice; the severity of the lesions was similar to that in mast cell-intact mice. In addition, BALF neutrophilia was elicited by mast cell reconstitution. A significant number of mast cells was found in the lungs of mast cell-reconstituted mice when silica was administered. These results suggest the involvement of mast cells in the development of silicosis and implicate interactions between mast cells and neutrophils in the pathogenesis of this disorder.

Animals↗
PubMed1993

Gene structure of bovine adrenodoxin reductase.

The gene structure of bovine adrenodoxin reductase, a component of the mitochondrial steroid hydroxylating system in the adrenal cortex, was determined. When we screened a bovine genomic DNA library, using bovine adrenodoxin reductase cDNA as a probe, we isolated 10 genomic clones covering a continuous 30 kilobase (kb) region of bovine chromosomal DNA in which the adrenodoxin reductase gene spanned approximately 12 kb. The adrenodoxin reductase gene consisted of 12 exons and all the donor and acceptor sites of the exon/intron junction followed the GT/AG rule. The transcription initiation site was found to be 79 bases upstream of the translation initiation site by primer extension analysis and putative CAAT and GC boxes, but no typical TATA box, were present in the 5'-flanking region. The 5'-flanking region of this gene showed several features characteristic of promoters of house-keeping genes. The CCAGGG sequence present in the 5'-flanking region of genes for adrenodoxin and the steroid hydroxylating cytochromes P-450 in the adrenal cortex was present 13 bases upstream from the transcription initiation site. We analyzed the promoter activity of the 5'-upstream region of this gene, using as a reporter the chloramphenicol acetyltransferase gene. The region between position -757 to -376 was proved necessary for expression of this gene in mouse Y-1 tumor cells. Adrenocorticotropin did not enhance the expression of this bovine gene in the cells.

Amino Acid Sequence↗
PubMed1993

Direct expression of adrenodoxin reductase in Escherichia coli and the functional characterization.

A plasmid for direct expression in Escherichia coli of the mature form bovine adrenodoxin reductase was constructed from the full-size cDNA for the enzyme [Y. Sagara, Y. Takata, T. Miyata, T. Hara, and T. Horiuchi, J. Biochem. (Tokyo), 102, 1333 (1987)] and an expression vector pCWori+. The recombinant adrenodoxin reductase was purified from the transformed E. coli cell lysates using adrenodoxin-Sepharose affinity chromatography [T. Sugiyama and T. Yamano, FEBS Lett., 52, 145 (1975)] with a yield of 2.5 mg/l of culture. The purified recombinant enzyme showed a single band on polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate and migration was identical with that of the authentic enzyme purified from bovine adrenal cortex mitochondria. The recombinant enzyme had Ser at its amino-terminus and the sequence of the amino terminal 9 residues was identical with that of the authentic bovine enzyme. The absorption spectrum of the recombinant enzyme showed peaks at 270, 376, and 450 nm and shoulders at 425 and 475 nm. Flavin content of the recombinant enzyme was 0.8 mol FAD/mol. The apparent Km value for bovine adrenodoxin in NADPH-cytochrome c reductase activity using a reconstitution system was 16 nM, a value comparable with that of the authentic bovine enzyme (17 nM). The cholesterol side chain cleavage activity with a reconstitution system was about 75% of that obtained when the authentic enzyme was used.

Adrenal Cortex↗