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Biomedical subjects

T Aoki

Publications and source records attributed to T Aoki.

At least 181 records · Page 10Linked to original sources

Hepatic encephalopathy caused by congenital extrahepatic portosystemic venous shunt.

Congenital portosystemic venous shunt is a relatively rare disease. Recently, a 60-year-old woman was admitted to our hospital for hepatic encephalopathy caused by congenital extrahepatic portocaval shunt. She had been in good health until the onset of this event, with no liver damage and no experience of abdominal surgery or history of abdominal trauma. In May 1993, hepatic encephalopathy manifested suddenly, with the chief complaint of orthostatic disturbance. Although conservative treatment was administered during the subsequent 5 years, on admission, liver damage and slight splenomegaly were shown, for which complete resection of the shunt vessel and splenectomy were performed. Postoperatively, the patient's symptoms have been alleviated. Hepatic encephalopathy caused by congenital portosystemic venous shunt requires long-term conservative treatment, and the patient's quality of life is reduced. For this reason, surgical intervention or embolization with interventional radiology should be considered, and the maintenance of hepatic blood flow should also be considered.

Female↗

Effect of a histamine H1 receptor antagonist on gastric endocrine cell proliferation induced by chronic acid suppression in rats.

The effect of histamine on gastrin cells and enterochromaffin-like cells has not yet been clarified. We investigated the influence of pyrilamine (a histamine H1 receptor antagonist) on serum gastrin level, gastrin cells, and enterochromaffin-like cells in rats with or without 4 weeks of famotidine treatment. The rats were divided into six groups: a control group, two pyrilamine groups (2mg/kg, or 20mg/kg, p.o.), a famotidine group (20mg/kg twice/daily i.m.), and two pyrilamine + famotidine groups. The serum gastrin concentration was determined, and gastrin cells and enterochromaffin-like cells were identified by the labeled streptavidin biotin complex method and counted. Hypergastrinemia, gastrin cell hyperplasia, and enterochromaffin-like cell hyperplasia were found after 4 weeks of famotidine treatment. Four weeks of treatment with pyrilamine alone did not affect the gastrin level, gastrin cells, or enterochromaffin-like cells in the rat stomach. When combined with famotidine, pyrilamine enhanced famotidine-induced hypergastrinemia, but it did not affect gastrin cell hyperplasia, and it significantly inhibited enterochromaffin-like cell hyperplasia. These results suggest that gastrin secretion and enterochromaffin-like cell proliferation may be regulated by histamine via the H1 receptor during acid suppression.

Animals↗

Effects of ecabet sodium on experimentally induced reflux esophagitis.

We investigated the effects of ecabet sodium on experimentally induced reflux esophagitis in rats. Three groups of rats, i.e., a control group, esophagitis group, and an ecabet sodium group (25mg/kg given twice daily) were used. The number of animals which developed esophagitis, the extent of the lesions, and the esophagitis lesion index were assessed 3 weeks after the start of the experiment, and the lesions were evaluated histopathologically. All nine surviving rats in the esophagitis group developed esophagitis, and the esophagitis lesion index was 32.6 +/- 7.2 (mean +/- SE) per animal. Histopathologically, thickening of the epithelium, elongation of papillae of the lamina propria into the epithelium, and infiltration of the lamina propria by lymphocytes, eosinophils, plasmacytes, and neutrophils, were observed. Interruption of the lamina of the muscularis mucosae was also observed, and there was marked proliferation of collagen fibers in the submucosa and lamina propria. In the ecabet sodium group, esophagitis developed in five of the nine surviving animals (55.6%), but the esophagitis lesion index was 1.89 +/- 0.73 per animal, which was significantly lower than that in the esophagitis group. The histopathological changes in the rats which developed esophagitis were milder in the ecabet sodium group than in the esophagitis group. These results suggest that ecabet sodium could be useful for the prevention of reflux esophagitis.

Abietanes↗

Metachronous triple cancers of the sigmoid colon, stomach, and esophagus: report of a case.

We report herein an unusual case of metachronous triple cancers of the sigmoid colon, stomach, and esophagus. A 60-year-old man was initially admitted to our hospital for investigation of occult fecal blood. This was found to be caused by sigmoid colon cancer which was resected in July 1985 (T3, N0, M0; Stage II). A follow-up endoscopy performed in 1990 showed early gastric cancer, and a gastrectomy was performed in August 1990 (Tis, N0, M0; Stage 0). Another endoscopic examination performed as follow-up in 1993 revealed early cancer of the remnant stomach, and all the remnant stomach was surgically resected in March 1993 (Tis, N0, M0; Stage 0). He presented again in December 1996, complaining of discomfort in the chest which was found to be caused by cancer of the middle thoracic esophagus. Although surgery was considered necessary, the patient refused to undergo any further operations. Instead, radiation was administered from January 1997. An endoscopy after the completion of radiotherapy confirmed that the cancer had almost disappeared; however, it started to grow again from the beginning of 1998. He was hospitalized due to esophageal stenosis in April 1998, and died of carcinomatous cachexia in September of the same year.

Adenocarcinoma↗

Ciliogenesis and ciliary abnormalities.

Cilia are motile processes extending from the basal bodies, playing important roles in the mucociliary clearance in the respiratory tract and the transport of the ovum from the ovary to the uterus in mammals. Ciliogenesis is divided into four stages: (1) duplication of centrioles; (2) migration of centrioles to the apical cell surface to become basal bodies; (3) elongation of cilia containing the axoneme; and (4) formation of accessory structures of basal bodies. The orderly course of ciliogenesis appears to be disturbed by various internal and external factors and, as a result, various unusual forms of the ciliary apparatus develop in the cell. Inhibition of basal body migration results in development of intracytoplasmic axonemes, cilia within periciliary sheaths, and intracellular ciliated cysts. Swollen cilia and the bulging type of compound cilia are formed during ciliary budding and elongation. This review also discusses the origin, composition, and function of the centriolar precursor structures.

Animals↗

Genomic bacterial artificial chromosome library of the Japanese flounder Paralichthys olivaceus.

We have constructed a genomic bacterial artificial chromosome (BAC) library from homozygous cloned Japanese flounder Paralichthys olivaceus using the pBAC- lac vector. This BAC library consists of about 49,100 clones and is deposited in 128 microtiter plates with 384 wells. The average size of inserted DNA was calculated to be 165 kb. The BAC library was determined to cover 9 times the Japanese flounder haploid genome. The Japanese flounder genomic BAC library will be useful for gene isolation as well as quantitative trait loci (QTL) analysis.

Journal Article↗

Molecular Cloning and Novel Repeated Sequences of a C-type Lysozyme Gene in Japanese Flounder (Paralichthys olivaceus).

A clone of a DNA fragment of approximately 10 kb that included a c-type lysozyme gene of Japanese flounder (Paralichthys olivaceus) was isolated from a Japanese flounder genomic DNA library. This clone was subcloned, and the nucleotide sequence of the c-type lysozyme gene was determined. The flounder c-type lysozyme gene, which consisted of 3,617 bp, was found to be composed of four exons and three introns. The transcription start site was determined to be 44 bp upstream of the ATG codon by primer extension analysis. The number of exons and introns and the positions of the catalytic residues of the flounder gene were the same as those of the human and chicken c-type lysozyme genes. However, introns 1 and 3 of the flounder gene were shorter, and intron 2 was longer, than those in the other reported vertebrates genes. There were no Alu repeated sequences in the flounder lysozyme gene, as determined for the human lysozyme gene, but 45 repeated sequences were found in the second intron of the flounder lysozyme gene. We suggest that the length of intron 2 in the Japanese flounder c-type lysozyme gene depends on the presence of this repeated sequence. Furthermore, Southern blot analysis revealed that the c-type lysozyme gene was probably a single copy in the genomic DNA of homo-cloned Japanese flounder.

Journal Article↗

Stable Expression of a Foreign Gene, Delivered by Gene Gun, in the Muscle of Rainbow Trout Oncorhynchus mykiss.

We report the efficient delivery of a foreign gene into muscle of rainbow trout Oncorhynchus mykiss with a gene gun. The foreign gene was a reporter gene, chloramphenicol acetyltransferase (CAT). Two CAT-containing plasmids were used: pCMV-CAT, which contains cytomegalovirus immediate early promoter, and pSV2-CAT, which contains the simian virus 40 early promoter. All plasmids were introduced by particle bombardment using a gene gun. During the 90-day sampling period following bombardment, CAT was strongly and stably expressed in the muscle of all the fish bombarded with pCMV-CAT and pSV2-CAT. No CAT expression was detected in the blood samples until 90 days after introduction, when it was found in only one fish from the pCMV-CAT group and one from the pSV2-CAT group. The stable and long-term expression of plasmid DNA in muscle makes muscle an attractive target tissue for the introduction of viral DNA for the purpose of DNA vaccination.

Journal Article↗

Better pulmonary function and prognosis with video-assisted thoracic surgery than with thoracotomy.

BACKGROUND: Data regarding pulmonary function and prognosis after video-assisted thoracic surgery lobectomy are limited. METHODS: From September 1992 to April 2000, 204 video-assisted thoracic surgery lobectomies were performed, and their preoperative and postoperative pulmonary function test results and prognoses were evaluated. RESULTS: The postoperative to preoperative ratio of pulmonary function tests (vital capacity and forced expiratory volume in 1 s) were better in video-assisted thoracic surgery lobectomy than in open thoracotomy (p < 0.0001). Furthermore, the 5-year survival rate of pathologic stage I lung cancers after video-assisted thoracic surgery was 97.0%, whereas that after open thoracotomy was 78.5% (p = 0.0173; Mantel-Cox). CONCLUSIONS: Pulmonary function and prognosis were far better after video-assisted thoracic surgery lobectomy than after open thoracotomy.

Adult↗

Effect of the lipoprotein lipase activator NO-1886 on adriamycin-induced nephrotic syndrome in rats.

Hyperlipidemia associated with nephrotic syndrome may play a role in the deterioration of renal function. Tsutsumi et al have previously reported that the novel compound NO-1886 increases lipoprotein lipase (LPL) activity, resulting in a reduction of plasma triglycerides and an elevation of high-density lipoprotein (HDL) cholesterol in normal rats. The aim of this study was to ascertain whether NO-1886 suppresses the renal injury by treatment of the hyperlipidemia in an Adriamycin (Kyowa Hakko Kogyo, Tokyo, Japan) induced nephrosis rat model fed a high-protein diet that induced renal dysfunction and tubulointerstitial injury. Administration of Adriamycin caused hyperlipidemia, proteinuria, and edema with ascites in rats in 4 weeks. Furthermore, a combination of Adriamycin and a high-protein diet increased plasma creatinine and blood urea nitrogen (BUN) and decreased plasma albumin. Histologically, in Adriamycin-treated rats, marked interstitial cellular infiltration, tubular lumen dilation, and tubular cast formation in the kidney were observed. NO-1886 decreased plasma triglyceride and increased HDL cholesterol in Adriamycin-induced nephrotic rats. NO-1886 treatment reduced plasma creatinine and BUN levels and increased plasma albumin in Adriamycin-treated rats; it also ameliorated the ascites and proteinuria. Histologically, NO-1886-treated rats showed a quantitatively significant preservation of tubulointerstitial lesions. These data suggest that NO-1886 may have a protective effect against Adriamycin-induced nephrosis with tubulointerstitial nephritis in rats by a modification of the plasma lipid disorder.

Animals↗

A survey of expressed genes in the leukocytes of Japanese flounder, Paralichthys olivaceus, infected with Hirame rhabdovirus.

We constructed a cDNA library of Japanese flounder, Paralichthys olivaceus, leukocytes that were infected with Hirame rhabdovirus (HRV) in order to analyze some of the genes that are induced and expressed by virus infection in the immune system. Four hundred and fifty-two partial sequences representing 300 cDNA clones were obtained from the 5' and/or 3' ends of inserts derived from the Japanese flounder leukocyte cDNA library. About three-quarters of the 300 cDNA clones (217 clones, 72.3%) represented known genes in the public databases, whereas the remaining 83 (27.7%) of the clones did not show any significant homology with the sequences in the public databases. Clones matching known genes were classified into 12 categories according to their function or distribution. Only 40 (18.4%) of the 217 known genes showed homology with fish genes deposited in the database. Thirty (10%) of the clones, encoding 21 different sequences, and representing several categories, were identified as putative biodefense genes or genes associated with the immune response. Nineteen of the 21 putative biodefense or immune response-related cDNAs have not been previously reported in fish genes or cDNAs.

Amino Acid Sequence↗

Cloning and analysis of expression of Mx cDNA in Japanese flounder, Paralichthys olivaceus.

Myxovirus resistance (Mx) is an interferon (IFN)-induced protein that specifically prevents growth, in vivo and in vitro, of certain classes of virus. We isolated the Mx cDNA from a leukocyte cDNA library obtained from a Japanese flounder infected with Hirame rhabdovirus (HRV). The Mx cDNA was found to contain 2385 bp coding for 620 amino acids. The amino acid sequence had approximately 51 and 78% identities to the sequences of human and rainbow trout Mx cDNAs, respectively. We propose that the amino acid sequence encoded by this cDNA clone contains a tripartite guanosine-5'-triphosphate (GTP)-binding motif, GXXXSGKS/T, DXXG and T/NKXD, and a signature of the dynamin family, LPRG(S/K)GIVTR, which are conserved in all IFN-induced Mx proteins of vertebrates. In addition, the C-terminal region of the Japanese flounder Mx protein, like those of other Mx proteins, contains a highly conserved leucine zipper motif. Japanese flounder infected with the HRV showed increased expression of Mx mRNA in the leukocytes starting at 48 h and peaking at 72 h. An RT-PCR (reverse transcription-polymerase chain-reaction) analysis of Mx mRNA from a healthy fish showed that the Mx mRNA was predominantly expressed in the kidney, spleen, intestine, brain, peritoneal cavity fluid and gill, and only minimally expressed in leukocytes, liver, muscle and mucus.

Amino Acid Sequence↗

Cloning and functional expression of Rpn1, a regulatory-particle non-ATPase subunit 1, of proteasome from Trypanosoma cruzi.

Non-lysosomal protein degradation in eukaryotic cells involves a proteolytic complex referred to as 26S proteasome that consists of a 20S core particle and one or two 19S regulatory particles. We have cloned the gene RPN1 encoding Rpnl (regulatory-particle non-ATPase subunit 1), one of the largest subunits of proteasome, from Trypanosoma cruzi. It contains 2712 bp and encodes 904 amino acid residues with a calculated molecular mass of 98.2 kDa and an isoelectric point of 5.2. The predicted amino acid sequence of the trypanosomatid Rpn1 shares 39.0 and 32.0% overall identities with human Rpn1 and Saccharomyces cerevisiae Nas1 (non-ATPase subunit 1), an Rpn1 homolog, respectively, while the sequence identities among T. cruzi, Plasmodium falciparum, and Entamoeba histolytica Rpnl are approximately 30%. T. cruzi Rpn1 contains nine repeats of about 36 amino acid residues conserved in Rpn1s from various organisms. T. cruzi RPN1 is located on the 2300- and 1900-kb chromosomal DNA, displays a putative allelic variation as RPN1-1 and RPN1-2 with 98.8% identity between these two putative gene products, and is transcribed from both alleles at a comparable level throughout the three developmental stages of the parasite, epimastigotes, trypomastigotes, and amastigotes. The expression of the trypanosomatid Rpnl in the temperature-sensitive nas1 yeast mutant rescued the growth defect at the restrictive temperature, indicating that Rpn1 functions as a Nas1 and probably assembles into the 19S regulatory particle of the yeast 26S proteasome.

Alleles↗

Effects of pertussis toxin on behavioral responses during different withdrawal periods from chronic cocaine treatment.

1. The role of Gi-proteins on cataleptic responses induced by SCH23390 and haloperidol in chronic cocaine-treated mice was examined by intracerebroventricullor (i.c. v.) and intravenous (i. v.) injections of pertussis toxin (PTX), which catalyzes adenosine diphosphate (ADP)-ribosylation of Gi-proteins. 2. In animals pretreated chronically with cocaine (10 mg/kg, s.c. on alternating days for 21 days), haloperidol (0.1 mg/kg i.p.) exerted an enhanced cataleptic response, but SCH23390 (0.1 mg/kg i.p.) produced an attenuated response at day 1, which converted to a supernormal response, when it was administered 20 days after the last cocaine injection. 3. The attenuated SCH23390 cataleptic response (D1 receptor supersensitivity induced one day after chronic cocaine treatment), was reversed one day after a single dose of PTX, which by itself had no effect, whereas the enhanced haloperidol catalepsy was further enhanced with same dose of toxin. 4. On the other hand, the enhanced SCH23390- and haloperidol-induced cataleptic responses seen during longer withdrawal period (20 days) were potentiated 20 days after a single coadministration of PTX. The stimulatory effects of PTX on the enhanced SCH23390-induced cataleptic response (D1 receptor subsensitivity induced during long-term withdrawal periods from chronic cocaine treatment), may be due to an indirect inhibition of D1 receptors (a synergistic effect) via blockade of postsynaptic dopamine D2 receptors. 5. The postsynaptic D1 receptor supersensitivity and D2 receptor subsensitivity induced one day after chronic cocaine treatment may involve greater Gi-protein ADP-ribosylation in the presynaptic cell body (VTA) than that in the postsynaptic cell body. On the other hand, the subsensitivity of postsynaptic dopamine D1 and D2 receptors (the enhanced SCH23390- and haloperidol-induced cataleptic responses) seen during longer withdrawal periods may mainly involve Gi-protein ADP ribosylation in the postsynaptic cell body, and which may be mediated by a PTX-sensitive muscarinic M2 and/orGABAB receptor activation.

Adenosine Diphosphate Ribose↗

Role of the phosphatidylinositol-specific phospholipase C pathway in delta-opioid receptor-mediated antinociception in the mouse spinal cord.

Stimulation of delta-opioid receptors has been shown to activate phospholipase C via the activation of G-proteins in vitro. The present study was designed to determine, with the tail-flick method, whether the stimulatory effect of delta-opioid receptor agonists on phospholipase C and inositol lipid turnover participates in the mechanisms of the delta-opioid receptor-mediated antinociception in the mouse spinal cord. Intrathecal pretreatment with the phospholipase C inhibitors neomycin and U73122, which produced no changes in the basal tail-flick latencies when they were injected alone, significantly attenuated the antinociception induced by intrathecal administration of the selective delta-opioid receptor agonist [D-Ala(2)]deltorphin II in mice. The selective phosphatidylinositol-specific phospholipase C inhibitor ET-18-OCH(3) inhibited the antinociception induced by intrathecal administration of [D-Ala(2)]deltorphin II in a dose-dependent manner. In mice undergoing treatment with LiCl, which impairs phosphatidylinositol synthesis, the antinociception induced by intrathecal administration of [D-Ala(2)]deltorphin II was significantly reduced. Co-administration of D-myo-inositol-1,4,5-trisphosphate restored the [D-Ala(2)]deltorphin II-induced antinociception in LiCl-pretreated mice. On the other hand, intrathecal pretreatment with the selective protein kinase C inhibitor calphostin C, but not the protein kinase A inhibitor KT5720, resulted in a dose-dependent enhancement of the [D-Ala(2)]deltorphin II-induced antinociception. These results indicate a potential role for the phospholipase C-inositol-1,4, 5-trisphosphate pathway in the expression of delta-opioid receptor-mediated antinociception in the mouse spinal cord. Furthermore, activation of protein kinase C by the stimulation of delta-opioid receptors may constitute a significant pathway involved in negative modulation of spinal delta-opioid receptor-mediated antinociception.

Analgesics↗