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Biomedical subjects

Y Adachi

Publications and source records attributed to Y Adachi.

At least 595 records · Page 33Linked to original sources
PubMed1993

The role of Kupffer cells in the surveillance of tumor growth in the liver.

The present study was designed to investigate the role of Kupffer cells (Kc) in the surveillance of liver tumors. We examined the antitumor activity of Kc by 51Cr releasing assay and inhibition of [3H]thymidine ([3H]TdR) incorporation into tumor cells. We also studied the change in the growth of liver tumors following the activation and the blockade of Kc. The cytotoxicity of Kc against K562 increased as the effector:target (E:T) ratio rose and reached its maximum level of about 18% at an E:T ratio of 20:1. [3H]TdR incorporation into target cells (P815 and AH130) was also inhibited by Kc. Such antitumor activity of Kc was augmented by OK432 (K562, from 13.8 +/- 5.6 to 21.9 +/- 2.5%; AH130, from 19.2 +/- 14.5 to 37.1 +/- 12.6%). In the experiment of the inoculation of AH130 via the portal vein, OK432 decreased the number of hepatic foci, whereas macrophage inhibitors carrageenan and gadolinium increased the number of tumor nodules. In addition, gadolinium injection reduced the number of Kupffer cells reactive with monoclonal antibodies directed against macrophages ED2 and Ki-M2R. Tumor growth in the liver was maximum in rats with both gadolinium treatment and splenectomy. In conclusion, Kc have antitumor activity, and augmentation of Kc may be a possible strategy to prevent hematogenous hepatic metastasis.

Animals↗
PubMed1993

HTLV-1 gene expression by defective proviruses in an infected T-cell line.

We have examined human T-lymphotropic virus type I (HTLV-I) gene expression in the human T-cell line, C8166-45 (C81), as a model to define the gene products expressed from defective proviruses. C81 cells contain one complete and two different deleted proviral genomes. The internal deletions of the latter encompass most of the gag to env region. All three proviruses are transcriptionally active as evidenced by the presence of three unspliced nuclear mRNAs. Unspliced genomic mRNAs and singly spliced env mRNAs were present in the nucleus, but were not detected in the cytoplasm, suggesting a defect in Rex function. Three small cytoplasmic mRNAs were observed and are likely to correspond to the normal 1.8-kb Tax1/Rex1 mRNA, a 1.6-kb mRNA formed by splicing the 5'LTR to the pX region, and a 2.1-kb mRNA of unknown origin. Consistent with the subcellular mRNA distribution pattern, the viral structural proteins encoded by gag and env genes were not detected. The transcriptional transactivator protein, Tax1 (p40), was abundantly expressed in C81 cells; in addition, a 42-kDa Tax1 protein, unique to this cell line, was also detected. Although Tax1 and Rex1 (p27) are translated from overlapping open reading frames in the same mRNA, Rex1 was not detected in C81 cells. The presence of a premature termination codon in the Tax1/Rex1 mRNA encoded by the full-length provirus was inferred from the presence of small Rex1-related polypeptides lacking C-terminal sequences and confirmed by sequence analysis. Furthermore, a p21X protein lacking the N-terminus of Rex1 was expressed at high levels; our data indicate that p21X is translated from the 1.6-kb mRNA which is derived primarily from deleted proviruses.

Blotting, Northern↗
PubMed1993

Functional integrity of hepatocyte canalicular membrane transport of taurocholate and bilirubin diglucuronide in Eisai hyperbilirubinuria rats.

Eisai hyperbilirubinuria rats (EHBR) are characterized by conjugated hyperbilirubinemia, and impaired or defective excretion of bilirubin, reduced glutathione and other organic anions from hepatocytes. Hepatocyte canalicular membrane vesicles (CMV) from EHBR and normal SD rats were studied with regard to taurocholate (TC) transport driven by ATP or a membrane potential and bicarbonate-stimulated bilirubin diglucuronide (BDG) transport. ATP-dependent uptake or association of BDG with CMV was also studied in both strains of rats. No significant differences in the uptake of TC and BDG by CMV were observed. This indicates the functional integrity of the canalicular transporters for both organic anions in EHBR. Biliary excretion of taurolithocholic acid sulfate (TLCS) is defective in EHBR. However, TLCS inhibited ATP-dependent TC uptake by SD rat CMV competitively, which may be against the hypothesis that a common organic anion carrier is defective in canalicular membranes of jaundiced rats.

Animals↗
PubMed1993

Prostaglandin E2 production by hepatic macrophages and peripheral monocytes in liver cirrhosis patients.

We analyzed PGE2 production in primary-cultured human hepatic macrophages (HHM phi) and peripheral monocytes (MO) from patients with and without liver cirrhosis, and correlated PGE2 production with the patients' liver function. Serum choline esterase (ChE) levels were used as an indicator of liver function. PGE2 production in both HHM phi and MO from cirrhotic patients was significantly lower than in HHM phi and MO from non-cirrhotic patients. PGE2 production in cirrhotic HHM phi was inversely correlated with ChE levels, whereas PGE2 production in cirrhotic MO showed no obvious correlation. In conclusion, both HHM phi and MO might contribute to the pathophysiology of liver cirrhosis via attenuated PGE2 production. Furthermore, HHM phi activity appears to be more strongly affected by the chronic pathological changes observed in the cirrhotic liver.

Cells, Cultured↗
PubMed1993

Analyses of thymic abnormalities in autoimmune-prone (NZW x BXSB) F1 mice.

Thymic abnormalities of autoimmune-prone (NZW x BXSB)F1 mice are investigated. After the onset of autoimmune diseases, severe thymic atrophy is observed. The atrophied thymus shows lower CD4+ CD8+ T cell and higher CD4+CD8- or CD4-CD8+ T cell counts than aged-matched normal strains or other autoimmune-prone (NZB x NZW)F1(B/WF1) mice; even at the age of 40 weeks, B/WF1 mice have a large number of double-positive cells and a small number of single-positive cells. Thymocytes in the atrophic thymus of (NZW x BXSB)F1 mice respond better than normal mice to T cell-mitogens (PHA and ConA). In addition, the single-positive T cells are J-11d-negative. These findings indicate that the atrophic thymus includes mature T cells and a large number of plasma cells and B cells; it therefore responds well to lipopolysaccharides. Experiments in reciprocal transplantation of the thymus and bone marrow between (NZW x BXSB)F1 and normal mice show that the thymic abnormalities are due to defects of the hemopoietic stem cells (HSCs) rather than either intrinsic abnormalities in the thymus or extrinsic abnormalities such as anti-thymus antibodies. It should be noted that the atrophic thymus recovers after transplantation of normal bone marrow cells; the atrophic thymus still has the capacity to induce the differentiation of normal T cells (including double-positive T cells) if normal HSCs are introduced.

Aging↗
PubMed1993

Clinical effect of WEB 1881 (nebracetam fumarate) on patients with dementia of the Alzheimer type and study of its clinical pharmacology.

We administrated WEB 1881, 800 mg/day (400 mg twice a day), nine patients with dementia of the Alzheimer type for 8 weeks, and undertook an open study to investigate the clinical effects of the distribution into the cerebrospinal fluid (CSF) as well as the influence on the neurotransmitter-related substances in the CSF. These were outpatients living at home with caregivers. Significant clinical improvement was shown by means of the Gottfries, Bråne, and Steen Scale and by Hasegawa's dementia scale. Unchanged WEB 1881 was identified in the CSF. The mean concentration of which was 198.7 ng/ml, this corresponded to 19.0% of the plasma concentration. Of several neurotransmitter-related substances measured in the CSF, a marked rise of AChE activity was observed. Adverse effects consisted of a slight skin eruption in one case and alterations in a clinical laboratory test in another case. These were, however, not significant from a clinical viewpoint. It is suggested that the mechanisms of action of WEB 1881 are based on its transit into the CSF as well as the activation of intracerebral acetylcholinergic systems.

Aged↗
PubMed1993

Benign gastric ulcer grossly resembling malignancy. A clinicopathologic study of 20 resected cases.

Twenty cases of benign gastric ulcers preoperatively interpreted to be malignant were reviewed clinicopathologically to clarify why these ulcers grossly appeared malignant. Macroscopically, the lesions often had an irregular margin (75%) and elevated surrounding mucosa (45%), and were often located on the greater curvature (40%) and near the pylorus (40%). Microscopically, most ulcers were large (21 mm) and shallow, reaching the submucosa (70%), and many were characterized by marked fibrosis (35%) and inflammatory cell infiltration (25%), sometimes accompanied by lymphoid hyperplasia. For such ulcers, which look malignant, careful examination by radiography, endoscopy, and biopsy should diminish the indications for surgery.

Adult↗
PubMed1993

Effect of transurethral resection of prostate on plasma hormone levels in benign prostatic hyperplasia.

Circulating levels of pituitary and adrenal hormones were measured in patients with benign prostatic hyperplasia before and after transurethral resection of the prostate (TURP). TURP caused a significant increase in plasma LH levels 2 weeks and 3 weeks after surgery. The plasma prolactin level decreased significantly 3 weeks after prostatectomy but plasma concentrations of FSH and ACTH were unchanged. TURP did not alter circulating levels of aldosterone, cortisol, DHEA-S and testosterone. These data suggest that the human prostate has a role in regulating the pituitary secretion of LH and prolactin.

Adrenal Cortex Hormones↗
PubMed1993

Nuclear Ribosomal DNA as a Probe for Genetic Variability in the Japanese Pear Pathotype of Alternaria alternata.

A restriction fragment length polymorphism analysis of nuclear ribosomal RNA genes (rDNA) was used to measure the amount and distribution of genetic variability in populations of the Japanese pear pathotype of Alternaria alternata on both micro- and macrogeographical scales. A total of 322 isolates were obtained from 13 areas in Aichi, Gifu, and Tottori Prefectures in central and western Japan. The restriction fragment length polymorphism analysis revealed that the pathogen populations contained at least eight rDNA variants. The eight variant types differed in the lengths and in the presence of the restriction sites in spacer DNA outside the coding regions for rRNAs. A total of 271 isolates were classified into the eight types. The remaining 51 isolates were determined to have mixed rDNA types. Single pear fields typically contained two to five types of rDNA variants. The frequencies of rDNA variants in 11 populations in Tottori Prefecture were compared; in this prefecture orchards containing the susceptible pear are common. Except for one collection site, there were no significant differences in the composition of the rDNA variants among the populations. This suggests that dispersal of inocula has occurred frequently in Tottori Prefecture. In contrast, significantly different distributions were observed in the three prefectures, indicating that gene flow between prefectures might be limited by geographical isolation. DNA fingerprints resulting from hybridization with a moderately repetitive DNA sequence of the fungus revealed greater genetic variability and geographical differences in genetic population structure even within the same rDNA type.

Journal Article↗
PubMed1993

Reproductive insufficiency in the male rat with adenine-induced chronic renal failure.

The effect of adenine-induced chronic renal failure on the male reproductive system was studied using male Wistar rats. On the 30th experimental day, serum creatinine and urea nitrogen were elevated in adenine-treated rats. Body weight ratio of the testes and serum levels of gonadotropins (luteinizing hormone and follicle-stimulating hormone) in adenine-treated rats were similar to those in the controls. Serum testosterone level was reduced in adenine-induced uremic rats, but serum concentrations of 17 alpha-hydroxyprogesterone and androstenedione were increased in the uremic group. These results suggest that adenine-induced chronic renal failure reduces testicular function by suppressing 17 beta-hydroxysteroid oxidoreductase which converts androstenedione to testosterone.

17-alpha-Hydroxyprogesterone↗
PubMed1993

Expression of interleukin 1 family mRNAs by a highly branched (1-->3)-beta-D-glucan, OL-2.

OL-2, a highly branched (1-->3)-beta-D-glucan, is an antitumor glucan showing strong hematopoietic activity with weaker adjuvant activity than schizophyllan (SPG), also an antitumor glucan and one which is clinically used. This paper deals with the gene expression of the interleukin 1 (IL-1) family in mice by OL-2 and SPG in order to characterize the immunopharmacological activity. Gene expression was examined by reverse transcriptase-polymerase chain reaction method. Intraperitoneal administration of OL-2 (250 micrograms/mouse) expressed all three genes of IL-1 alpha, beta, and IL-1 receptor antagonist (IL-1ra) in the peritoneal exudate cells, while SPG induced a strength of IL-1 alpha mRNA comparable to that by OL-2 but a weaker level of IL-1 beta mRNA. SPG did not induce IL-1ra. Similar patterns were seen in spleen and liver by OL-2 or SPG administration. These findings suggest that the immunopharmacological characteristics of (1-->3)-beta-D-glucan are regulated under the gene expression of the IL-1 family.

Animals↗
PubMed1993

Serum components induce beta-D-glucan-inhibitable uptake of zymosan particles by murine peritoneal macrophages.

Effects of murine serum (NMS) treatment on (1-->3)-beta-D-glucan inhibitable uptake of zymosan particles (ZYM) (GIZUP) by murine peritoneal macrophages (PM) and the structural specificity of the inhibition were examined. ZYM uptake by PM treated with NMS was enhanced in comparison with those treated with medium, and in a concentration- and incubation time-dependent manner. The enhanced ZYM uptake was significantly reduced by the pretreatment of PM with soluble (1-->3)-beta-D-glucans. These facts suggest that NMS enhances GIZUP. The effect disappeared by the treatment of NMS with gelatin-Sepharose which removed fibronectin (FN) from the serum, suggesting a significant contribution of FN on GIZUP. In addition, the administration of beta-glucan in vivo elevated the concentration of FN in serum by acute phase response and enhanced GIZUP, suggesting the positive contribution of acute phase responses on beta-glucan mediated immunopharmacological activities. Of particular interest, the inhibition was shown by both antitumor active and inactive glucans. These facts suggested that the recognition of beta-glucans by PM, which would proceed at a relatively early period of whole activation pathways, would not be enough to fully activate the host to show antitumor activity.

Animals↗
PubMed1993

Binding of lysozyme to synthetic monosaccharide lipid A analogue, GLA60.

Recent studies by our group suggested that lysozyme (LZM) has a high affinity for bacterial lipopolysaccharide (LPS) of both the smooth and rough forms, and inhibits various immunomodulatory activities of LPS. GLA60 is a synthetic monosaccharide analogue of bacterial lipid A, well-known as sharing large part of lipid A activities but with very low toxicity. In this study, we characterized the interaction of LZM with GLA60 in comparison to that with E. coli 0111 LPS (smooth form), taking a physicochemical approach. Using a dansylated lysozyme probe (DNS-LZM), LZM was found to bind to GLA60 in all 3 of its forms, free acid, triethylamine (TEA) salt and bovine serum albumin (BSA) complex of GLA60, as well as natural LPS. Compared with LPS, the complex formation of the TEA salt was weakly dependent on temperature and incubation time. LZM also bound to biologically inactive GLA analogues, GLA 64 and GLA69, at a high affinity, as well as to GLA 60. By using chemically modified LZM, it was found that the ionic as well as hydrophobic interactions are important for the complex formation.

Chemical Phenomena↗
PubMed1993

Immunopharmacological characterization of a highly branched fungal (1-->3)-beta-D-glucan, OL-2, isolated from Omphalia lapidescens.

The immunopharmacological activities of a fungal (1-->3)-beta-D-glucan, OL-2, isolated from "Leiwan" Omphalia lapidescens were examined. Intraperitoneal (i.p.) administration of OL-2 to ICR mice induced a significant number of peritoneal exudate cells (PEC) and white blood cells over the period of a few days. Spleen cell numbers were also increased by i.p. administration of OL-2 at about a week. These changes reverted to the normal level within a month. Responses of spleen cells and bone marrow cells (BM) to colony stimulating factors (CSF) were augmented by OL-2 administration assessed by cell proliferation assay. Sera from OL-2 administered mice contained an increased concentration of colony stimulating activity. Gene expressions of interleukin-1 beta, interleukin-6, and tumor necrosis factor alpha in the spleen were also increased. These results suggested the activation of hematopoietic responses, and would well relate to the incremental increase in PEC, white blood cell and spleen cell numbers. OL-2 also increased the serum concentration of fibronectin and complement component C-3. However, OL-2 did not show adjuvant activity to SRBC and antitumor activity against the solid form of Sarcoma 180 by i.p. administration. Yet, OL-2 did not interfere with the antitumor activity of SSG against the same tumor system. These facts suggested that OL-2 could enhance nonspecific host defense mechanisms by enhancing hematopoietic responses, but would not enhance or inhibit the specific immunity mediated by lymphocytes.(ABSTRACT TRUNCATED AT 250 WORDS)

Adjuvants, Immunologic↗
PubMed1993

Inhibitory effect of beta-glucans on zymosan-mediated hydrogen peroxide production by murine peritoneal macrophages in vitro.

Effects of the pretreatment of murine peritoneal macrophages with several polysaccharides on the production of H2O2 induced with unopsonized zymosan were examined. Pretreatment with most of (1-->3)-beta-D-glucans for 6 h at 37 degrees C inhibited the zymosan-mediated H2O2 production by macrophages. The phorbol myristate acetate (PMA)-mediated H2O2 production was not affected by the pretreatment. The pretreatment of macrophages with (1-->3)-beta-D-glucans decreased the ability to ingest unopsonized zymosan, but did not affect the ingestion of IgG-coated sheep red blood cells (IgG-SRBC). These results suggested that the pretreatment with (1-->3)-beta-D-glucans interfered with the interaction of macrophages to zymosan and that the occupation of the receptor for the (1-->3)-beta-D-glucans inhibited zymosan-mediated production of H2O2 by macrophages. Chemical modification by substitution with carboxymethyl groups or hydroxyethyl groups of a (1-->6)-branched (1-->3)-beta-D-glucan reduced the inhibitory effect of pretreatment on zymosan-mediated H2O2 production. The above results indicated the possibility that murine peritoneal macrophages possess certain receptors for beta-anomeric glucans, and one ligand specificity of the receptors is to restrict the intact (1-->3)-beta-D-glucosyl back bone.

Animals↗
PubMed1993

Application of limulus test (G pathway) for the detection of different conformers of (1-->3)-beta-D-glucans.

The reactivity of factor G mediated coagulation pathway in limulus amebocyte lysate which is triggered by (1-->3)-beta-D-glucans is thought to depend on the structure of the glucans, especially on the ultrastructure: triple helix, single helix and random coil. We used Sonifilan (SPG) and grifolan (GRN) as parent compounds to compare the reactivities of these three conformers. Under a neutral condition, alkaline treated SPG (SPG-OH, single helix) and polycarboxylated SPG (PC-SPG, random coil) showed significantly stronger reactivity than untreated SPG (triple helix). After the alkaline treatment, all three conformers showed comparable reactivities. It is suggested that the pretreatment of the glucan preparations by sodium hydroxide is quite important to compare quantitatively the reactivity of the glucans by limulus test, and comparing the data of untreated and alkaline treated glucans would provide information about their conformations. Using this approach, it was found that after heat treatment at around 150 degrees C, the conformation of GRN was changed to rich in the triple helix, and that following sodium hydroxide treatment and dialysis of GRN, the conformation of GRN was changed to single helix rich conformer. About half of the single helix conformer was gradually changed to triple helix conformer over one week at 4 degrees C.

Carbohydrate Conformation↗
PubMed1993

Blind loop syndrome: multiple ileal ulcers following side-to-side anastomosis.

A 59 yr old woman who had multiple ileal ulcers following side-to-side anastomosis without bowel resection is reported. She had a surgical history of adhesive ileus 15 yrs earlier, and was admitted with a complaint of lower abdominal pain. A barium meal study showed a stagnant and dilated distal ileum. At laparotomy, a previously performed side-to-side ileal anastomosis was encountered, and a markedly dilated bypassed loop was recognized. The affected intestine was resected revealing multiple longitudinal ulcers and small shallow ulcers mostly located on the mesenteric side. This feature is similar to that of ischemic enteritis. This case further supports the fact that when side-to-side anastomosis is performed as a bypass operation, multiple ulcers may develop in a bypassed loop after a long period of time.

Anastomosis, Surgical↗