<ORIGINAL REPORT>THE ULTRASTRUCTURE OF THE CLARA CELL IN THE BRONCHIOLAR EPITHELIUM

この論文は国立情報学研究所の学術雑誌公開支援事業により電子化されました。The terminal bronchiolar epithelium of the mouse and the guinea pig were examined with the scanning electron microscope and the conventional electron microscope. The ciliated cells and the Clara cells were well preserved and it is possible to discern individual cell with the scanning electron microscope. The apical part of the cytoplasm containing the agranular endoplasmic reticulum was occasionally seen to be extruded into the bronchiolar lumen. This finding indicated that the Clara cell has an apocrine secretory function. Osmiophilic lamellar inclusions are rarely found in this cell. However, there is no proof that they are the important source of the pulmonary surfactant

A New Method for the Production of Tungstic Acid from Tungstates

This paper deals with a characteristic property of tungstic acid and its reaction with hydrochloric acid solution. The authors' experiments prove that tungstic acid freshly formed from tungstate by decomposition with hydrochloric acid, dissolves in its concentrated acid solution forming a chemical compound, provided that the produced tungstic acid is brought into contact with concentrated hydrochloric acid immediately after its formation. It was found also that if the degree of its concentration 1s reduced, this chemical compound gives the insoluble tungstic acid as a precipitate in the solution. Details are given for lixiviating the tungstic acid from tungstate · and for preparing it

Characteristics of human erythrocyte insulin binding sites.

Insulin and human erythrocyte cell membrane interactions were studied with respect to binding and dissociation. The per cent of specific binding of 125I-labeled insulin to erythrocytes was directly proportional to the cell concentration. The optimum pH for binding was 8.1. The initial binding rate was directly proportional to, and the steady state insulin binding was reversely proportional to, the incubation temperature. The per cent of specific binding of 125I-labeled insulin was 12.10 +/- 1.13 per cent (mean +/- SD)/4 X 10(9) cells (n = 10) at 0.8 ng/ml insulin. Native insulin competed with 125I-labeled insulin for binding and showed almost complete inhibition at 10(4) ng/ml. The Scatchard plots were upward concave. Maximum binding capacity was 230 binding sites per cell. The average affinity constant decreased as the per cent of fractional occupancy increased. Affinity constants for the empty and filled sites were 1.49 and 0.16 X 10(8) M-1 respectively. Bound insulin was displaced by native insulin. The dissociation rate by &#34;dilution + native insulin&#34; was higher than that by &#34;dilution only&#34;. The dissociation rate was accelerated even by the physiological concentration of insulin and maximum at 100 ng/ml. It is concluded that human erythrocytes have insulin binding sites which are indistinguishable from insulin receptors on the target tissues for insulin.</p

Increased insulin binding to erythrocytes in chronic liver disease.Increased insulin binding to erythrocytes in chronic liver disease.

125I-labeled insulin binding to peripheral human erythrocytes was studied in patients with chronic liver disease. The maximum specific 125I-labeled insulin binding was 12.10 +/- 1.13 %/4 x 10(9) cells (mean +/- SD, n = 10) in normal subjects, and significantly higher in cirrhotic patients (15.32 +/- 1.73 %, n = 11, P less than 0.01) but not in patients with acute and chronic hepatitis (11.44 +/- 2.10 %, n = 3 and 13.2 +/- 1.87 %, n = 7 respectively). The complication of diabetes mellitus significantly increased (P less than 0.05) the maximum insulin binding in chronic hepatitis. Scatchard analysis and average affinity analysis of the binding data suggest that increased insulin binding in cirrhotic patients is due to an increase in the number of insulin binding sites per erythrocytes. The complication of diabetes in chronic liver diseases results in an increase in affinity of insulin binding sites.</p

Synthesis and Biological Applications of Oligopeptide-Substituted Polynorbornenes

Chapter 1 Synthetic fibronectin mimics have been constructed usmg functionalised norbomenyl polymers synthesized via ring-opening metathesis polymerization (ROMP). The ROMP reactions were catalyzed by newly developed ruthenium initiators. Prior to the synthesis of the fibronectin mimics, the polymerization reactions of a number of norbornene derivatives with pendent glycine or penta(ethylene oxide) (EO5) units were studied in order to select the derivatives with optimal characteristics: high yields, fast polymerization times, and narrow PDI's. For these initial studies Ru = CHPh(Cl2)(PCy3)2 (1) was used as the initiator. Based on these studies poly(5-norbomene-2-carboxyl) and poly(4-(Exo-3,5-dioxo-10-oxa-4-azatricyclo[5.2.1.0]dec-8-en-4-yl)-butyric acid) were chosen as the ideal backbones for a series of polymers functionalised with pendent arginine-glycine-aspartic acid (RGD) and serine-arginineasparagine (SRN) oligopeptides. The polymers containing a propyl spacer between the pendant group and the backbone were synthesized in an attempt to demonstrate that the presentation of the peptide units could be altered to closely mimic the natural presentation of these peptides in fibronection. Homopolymers and random copolymers containing various combinations of norbomene monomers with pendant EO5 (21 &amp; 14), GRGD/RGD (24 &amp; 29), and SRN (25 &amp; 30) units were made. Copolymers with large RGD or SRN contents (&gt; 10 mol %) could only be synthesised in high yields and narrow PDI's by using the newly developed ruthenium 2,3-dihydroimidazolylidene initiators Ru = CHPh(Cl)2(PCy3)(DHIMes) (2) or Ru = CH-CH = CH2(CH3)2(Cl)2 PCp3)(DIHMes) (3). In addition, the ROMP reactions of the norbornene monomers containing the propyl spacers also required the new initiator 2. Attempts to synthesize these polymers using ruthenium initiator 1 resulted in either low yields, bimodal molecular weight distributions, or a combination of both. Chapter 2 Polynorbomenes substituted with two different peptide sequences from the RGD containing integrin cell binding domain of fibronectin are potent inhibitors of human foreskin fibroblast cell adhesion to fibronectin-coated surfaces. Ring-opening metathesis polymerization (ROMP) using Ru = CHPh(Cl)2(PCy3)(DHIMes) (1) as an initiator produced polymers substituted with GRGDS and PHSRN peptide sequences. The inhibitory activity was quantified for these polymers and compared to the free peptides and GRGES containing controls. A homopolymer substituted with GRGDS peptides was significantly more active than the free GRGDS peptide (IC50 of 0.18 ± 0.03 and 1.33 ± 0.20 mM respectively), and the copolymer containing both GRGDS and PHSRN was the most potent inhibitor (IC50 of 0.04 ± 0.01 mM). These results demonstrate that significant enhancements of observed biological activity can be obtained from polymeric materials containing more than one type of multivalent ligand and that ROMP is a useful method to synthesize such well-defined copolymers.</p

Different expression of Tn and sialyl-Tn antigens between normal and diseased human gastric epithelial cells.

Thomsen-Friedenreich antigen (T antigen) has been supposed to be a cancer-specific carbohydrate antigen. We have previously shown that one third of the Japanese population normally expressed T antigen in gastric surface epithelia and the other two thirds expressed fucosyl-T antigen. Their sialylation and blocked-synthesis were associated with diseased conditions. In the present study, we studied gastric surface epithelial expression of monosaccharide antigen Tn, i.e., a precursor of T antigen, and sialyl-Tn. Normal fundic and pyloric epithelia, respectively, expressed Tn supranucleally and cytoplasmically, but did not express sialyl-Tn. In the intestinal metaplasias and intestinal-type adenomas, goblet cells expressed sialyl-Tn in their vacuoles, and absorptive cells expressed Tn apically. In gastric-type adenomas, Tn, but not sialyl-Tn, was detected. Intestinal-type cancers expressed Tn and sialyl-Tn more often than the diffuse-type cancers. Five cancers did not express Tn, sialyl-Tn, or the T-related antigens. In these, four were diffuse-type cancers. We concluded that: a) normal gastric epithelial cells express Tn; b) metaplastic differentiation is associated with sialylation of Tn and c) expression of Tn and sialyl-Tn is depressed in the gastric cancers. </p

The 5'-3' exoribonuclease pacman is required for epithelial sheet sealing in Drosophila and genetically interacts with the phosphatase puckered

Background information. Ribonucleases have been well studied in yeast and bacteria, but their biological significance to developmental processes in multicellular organisms is not well understood. However, there is increasing evidence that specific timed transcript degradation is critical for regulation of many cellular processes, including translational repression, nonsense-mediated decay and RNA interference. The Drosophila gene pacman is highly homologous to the major yeast exoribonuclease XRN1 and is the only known cytoplasmic 5′–3′ exoribonuclease in eukaryotes. To determine the effects of this exoribonuclease in development we have constructed a number of mutations in pacman by P-element excision and characterized the resulting phenotypes. Results. Mutations in pacman resulted in flies with a number of specific phenotypes, such as low viability, dull wings, crooked legs, failure of correct dorsal/thorax closure and defects in wound healing. The epithelial sheet movement involved in dorsal/thorax closure is a conserved morphogenetic process which is similar to that of hind-brain closure in vertebrates and wound healing in humans. As the JNK (c-Jun N-terminal kinase) signalling pathway is known to be involved in dorsal/thorax closure and wound healing, we tested whether pacman affects JNK signalling. Our experiments demonstrate that pacman genetically interacts with puckered, a phosphatase that negatively regulates the JNK signalling pathway. Conclusions. These results reveal that the 5′–3′ exoribonuclease pacman is required for a critical aspect of epithelial sheet sealing in Drosophila. Since these mutations result in specific phenotypes, our data suggest that the exoribonuclease Pacman targets a specific subset of mRNAs involved in this process. One of these targets could be a member of the JNK signalling pathway, although it is possible that a parallel pathway may instead be affected. The exoribonuclease pacman is highly conserved in all eukaryotes, therefore it is likely that it is involved in similar morphological processes, such as wound healing in human cells

Supporting data in ENDNOTE for: focused ultrasound transiently increases membrane conductance in isolated crayfish axon

NSF (#1707865, PI – Okada

Increased serum levels of the carrier molecules of the carbohydrate antigen sialyl Lewis X in liver diseases

The serum levels of the carbohydrate antigen sialyl Lewis X (SLEX) increase in liver diseases (Sunayama T, Okada Y, Tsuji T., J Hepatol 1994; 19: 451-458). However, it is not known whether the increased serum SLEX levels are associated with the increased levels of its carrier molecules and/or the increased density of SLEX per carrier molecule. By using of rabbit antibody against an SLEX-positive fraction from HepG2 culture supernatant, we developed an enzyme-linked immunosorbent assay to determine the serum levels of the carrier molecules of SLEX (CMSLEX). The CMSLEX-levels in patients with hepatocellular carcinoma were significantly higher than those of normal controls (P &#60; 0.001) and benign chronic liver diseases, i.e., chronic active hepatitis, mild and severe form, and liver cirrhosis (P &#60; 0.05). Patients with chronic persistent hepatitis and chronic active hepatitis, mild form, had higher CMSLEX-levels than normal controls (P &#60; 0.05). The serum CMSLEX-levels did not differ significantly among benign liver diseases. We concluded that serum CMSLEX-levels increase nonspecifically in liver diseases. This is a possible molecular mechanism for the increased serum SLEX levels in liver diseases.</p