Labeling of phosphorothioate antisense oligonucleotides with yttrium-90

Novel yttrium-90 (90Y)-labeled phosphorothioate antisense oligonucleotides were designed as a potential targeted radionuclide therapeutic agent for malignant tumors. A 15-mer phosphorothioate antisense oligonucleotide, which was complementary to the translation start region of the N-myc oncogene mRNA, was conjugated with isothiocyanobenzyl ethylenediamine tetraacetic acid (SCN-Bn-EDTA), via a C-5-substituted deoxyuridine that had replaced a thymine in the oligonucleotide, and was then labeled with 90Y-acetate. Following purification, the radiochemical purity of the 90-Y-Bn-EDTA-phosphorothioate antisense oligonucleotides was estimated by 2.0% agarose gel electrophoresis, and the specific hybridization of 90Y-Bn-EDTA-phosphorothioate antisense oligonucleotide to a phosphorodiester sense oligonucleotide was investigated by 20% polyacrylamide gel electrophoresis in a cell-free system. Radiochemical purity was 98.7 +/- 0.4% at 72 h after labeling and 90.3 +/- 0.9% after 72-h incubation with human normal serum. The 90Y-Bn-EDTA-phosphorothioate antisense oligonucleotide hybridized specifically to a complementary phosphorodiester sense oligonucleotide. In conclusion, phosphorothioate antisense oligonucleotides can be labeled stably with 90Y using SCN-Bn-EDTA without loss of hybridization properties.

Receptive-field properties of adult cat's retinal ganglion cells with regenerated axons

Receptive-field properties of retinal ganglion cells (RGCs) that had regenerated their axons were studied by recording single-unit activity from strands teased from peripheral nerve (PN) grafts apposed to the cut optic nerve in adult cats. Of the 286 visually responsive units recorded from PN grafts in 20 cats, 49.7% were classified, according to their receptive-field properties, as Y-cells, 39.5% as X-cells, 6.6% as W-cells, and 4.2% were unclassified. The predominant representation of Y-cells is consistent with a corresponding morphological study (Watanabe et al. 1993a), which identified alpha-cells as the RGC type with the largest proportion of regenerating axons. Among the X-cells, we only found ON-center types, whereas both ON-center and OFF-center Y-cells were found. As in intact retinas, the receptive-field center sizes of Y-cells and W-cells were larger than those of X-cells at corresponding displacements from the area centralis. Within the 10 degrees surrounding the area centralis, the receptive fields of X-cells with regenerated axons were larger than those in intact retinas, suggesting that some rearrangement of retinal circuitry occurred as a consequence of degeneration and regeneration. Receptive-field center responses of Y-, X-, and W-type units with regenerated axons were similar to those found in intact retinas, but the level of spontaneous activity of Y- and X-type units was, in general, less than that of intact RGCs. Receptive-field surrounds were weak or not detected in more than half of the visually responsive RGCs with regenerated axons.

Angiomyolipoma of the liver: case report and collective review of cases diagnosed from fine needle aspiration biopsy specimens

We experienced a rare case of primary angiomyolipoma (AML) of the liver, preoperatively diagnosed by fine needle aspiration biopsy (FNAB). Radiographic imaging revealed characteristic features of an angiomyolipoma. The diagnosis was confirmed by the presence of epithelioid smooth muscle cells, mature fat cells and blood vessels in the biopsy tissue. Our review of the literature showed this to be the eleventh case to be diagnosed in this way. Despite this preoperative diagnosis, the lesion was resected because of its pleomorphic histological features. Histologically, the epithelioid smooth muscle component included cells with a bizarre appearance and occasional hyperchromatic nuclei, and furthermore, occasional mitotic figures were observed. In own MEDLINE search of the literature we found 11 cases of AML of the liver for which the diagnoses were established by FNAB, and the same features were present in 5 cases for which surgical excision was contemplated.

Prenatal diagnosis of thanatophoric dysplasia by mutational analysis of the fibroblast growth factor receptor 3 gene and a proposed correction of previously published PCR results

Thanatophoric dysplasia (TD) is the most frequent form of neonatal lethal skeletal dysplasia. Recently. mutations in the fibroblast growth factor receptor 3 (FGFR3) gene that cause two subtypes of this disorder, type I (TDI) and type II (TDII), have been identified. This discovery has now made it possible to make a definite diagnosis of TD by molecular methods. To date, prenatal diagnosis of TD has been accomplished by ultrasonography in the second trimester. However, it is not always possible to distinguish TD fetuses it utero from the other osteochondrodysplasias by ultrasonography or radiography. We report on the prenatal diagnosis of a TD fetus, showing severe shortness of limbs and polyhydramnios, by identification of a mutation in the FGFR3 gene. Genomic DNA was isolated from the amniotic fluid and then subjected to PCR amplification. The common TDI mutation, C-->T transition at nucleotide 742 in the FGFR3 gene, was identified using restriction enzyme analysis. This information was critical in obstetric management decisions later in pregnancy. However, although the mutation responsible for TDI was detected previously, we noticed some inconsistencies in the published PCR results and have proposed a correction.

Novel missense mutation resulting in the substitution of tyrosine by cysteine at codon 597 of the type X collagen gene associated with Schmid metaphyseal chondrodysplasia

Schmid metaphyseal chondrodysplasia (SMCD) is one of the most common forms of the osteochondrodysplasias. Mutations or deletions in the COL10A1 gene that encodes type X collagen have been shown to cause this disorder. Most of the gene mutations and deletions are located in the non-collagenous carboxy (C)-terminal (NC1) domain. We describe a novel missense mutation in a patient with SMCD that leads to the substitution of Tyr at codon 597 by Cys in the NC1 domain. Sequence analysis indicated that the proband was heterozygous for the mutation. Her parents were homozygous for the normal sequence, indicating the de-novo occurrence of this mutation.

A novel class of orally active non-peptide bradykinin B2 receptor antagonists. 4. Discovery of novel frameworks mimicking the active conformation

In recent articles we reported the identification of a series of 8-[[2, 6-dichloro-3-[N-methyl-N-[(E)-(substituted)acryloylglycyl]amino]++ +benzy l]oxy]-2-methylimidazo[1,2-a]pyridines as the first orally active non-peptide bradykinin (BK) B2 receptor antagonists. Optimization of the terminal glycine part and the imidazo[1,2-a]pyridine moiety led to the discovery of a clinical candidate (5, FR173657). With the aim of completion of the structure-activity relationship (SAR) study, we next investigated the roles of the substituents on the central phenyl ring. The results suggested that the 2,6-dichloro or 2, 6-dimethyl groups may play important roles in regulating the conformations of the 1- and 3-substituents and also may interact with hydrophobic pockets of the B2 receptors. Furthermore, according to the results of a molecular modeling study reported in part 1 of this series, we designed and synthesized a series of sterically constrained analogues by replacing the N-methylamide group with cis-amide-like rigid moieties. We discovered several bioisosteres and chemically proved that the N-methylamide moiety adopts the cis-amide form in the active conformation. Extensive chemical modification led to the identification of a novel class of highly potent and orally active non-peptide B2 antagonists represented by a pyrrole derivative (52a, FR193517). Compound 52a inhibited the specific binding of [3H]BK to recombinant human B2 receptors expressed in Chinese hamster ovary (CHO) cells and guinea pig ileum membrane preparations expressing B2 receptors with IC50s of 0.37 and 0.56 nM, respectively. This compound also displayed excellent in vivo functional antagonistic activity against BK-induced bronchoconstriction in guinea pigs at 1 mg/kg by oral administration.

A novel class of orally active non-peptide bradykinin B2 receptor antagonists. 2. Overcoming the species difference between guinea pig and man

Recently we reported the identification of a series of 8-[[3-(N-acylglycyl-N-methylamino)-2, 6-dichlorobenzyl]oxy]-3-halo-2-methylimidazo[1,2-a]pyridines as the first orally active non-peptide bradykinin (BK) B2 receptor antagonists (1-3). These compounds inhibited the specific binding of [3H]BK to guinea pig ileum membrane preparations expressing B2 receptors with nanomolar IC50's and also displayed in vivo functional antagonistic activities against BK-induced bronchoconstriction in guinea pigs at 1 mg/kg by oral administration. However, it was found that their affinities for the B2 receptors in human A-431 cells (human epidermoid carcinoma) were much lower. Intensive modifications of the terminal substituents at the glycine moiety elucidated the structure-activity relationships (SAR) for human B2 receptors, leading to an extended basic framework which incorporated a novel key pharmacophore. Thus, we overcame the species difference and identified the first clinical candidate 18c (FR167344) with IC50's of 0.66 and 1.4 nM for guinea pig ileum and human A-431 cells, respectively. This compound displayed in vivo functional antagonistic activity against BK-induced bronchoconstriction in guinea pigs with an ED50 value of 0.17 mg/kg by oral administration. This novel non-peptide B2 antagonist is extremely potent both in vitro and in vivo by oral administration and is expected to be the first member of a new class of drug for the treatment of various inflammatory diseases.

A novel class of orally active non-peptide bradykinin B2 receptor antagonists. 3. Discovering bioisosteres of the imidazo[1,2-a] pyridine moiety

Recently we reported on overcoming the species difference of our first orally active non-peptide bradykinin (BK) B2 receptor antagonists, incorporating an 8-[[3-(N-acylglycyl-N-methylamino)-2, 6-dichlorobenzyl]oxy]-3-halo-2-methylimidazo[1,2-a]pyridine skeleton, leading to identification of the first clinical candidate 4a (FR167344). With this potent new lead compound in hand, we then investigated further refinement of the basic framework by replacement of the imidazo[1,2-a]pyridine moiety and discovered several bioisosteric heterocycles. Extensive optimization of these new heteroaromatic derivatives revealed the detailed structure-activity relationships (SAR) around the imidazo[1, 2-a]pyridine ring and the 2,6-dichlorobenzyl moiety, leading to the discovery of our second clinical candidate 87b (FR173657) which inhibited the specific binding of [3H]BK to recombinant human B2 receptors expressed in Chinese hamster ovary (CHO) cells and guinea pig ileum membrane preparations expressing B2 receptors with IC50's of 1.4 and 0.46 nM, respectively. This compound also displayed excellent in vivo functional antagonistic activity against BK-induced bronchoconstriction in guinea pigs with an ED50 value of 0.075 mg/kg by oral administration. Further modifications of the terminal substituents on the pyridine moiety led to a novel pharmacophore and resulted in the identification of 99 (FR184280), whose IC50 value for human B2 receptors (0.51 nM) was comparable to that of the second-generation peptide B2 antagonist Icatibant.

Effect of the carbamoyl group attached to an axial ligand portion of a novel bleomycin model on a dioxygen activating reaction

A Fe complex of a novel bleomycin model compound bearing a diaminopropionamide (DAPA) moiety as the axial ligand and a long alkyl chain as the steric factor around the 6th coordination site promoted reversible redox reaction and exhibited high oxygen activating ability. Kinetic analysis of the redox reaction in the presence of dioxygen and a reducing agent revealed that the presence of the carbamoyl group on the DAPA moiety facilitates the oxygenation-activation process of the Fe(II) complex, and the reduction process of the resulting Fe(III) complex.

Effects of a nonpeptide bradykinin B2 receptor antagonist, FR167344, on guinea-pig tracheal smooth muscle bradykinin receptors

It is speculated that bradykinin may play an important role in asthma. Thus, bradykinin receptor antagonists may have therapeutic potential against asthma. Orally active bradykinin antagonists would be more desirable for the treatment of the disease. In the present study, we examined the effects of a novel, potent, selective, and orally active nonpeptide bradykinin B2 receptor antagonist, FR167344 (N-[N-[3-[(3-bromo-2-methylimidazo[1,2-a]pyridin-8-yl)oxymethyl]-2 ,4-dichlorophenyl]-N-methylaminocarbonylmethyl]-4-(dimethylamin ocarbonyl)cinnamylamide hydrochloride), on guinea-pig tracheal smooth muscle bradykinin receptors. FR167344 inhibited [3H]bradykinin binding to bradykinin receptors in epithelium-denuded guinea-pig tracheal membrane with an IC50 of 2.1 nM and a Ki of 0.44 nM. This compound also inhibited bradykinin-induced contraction of epithelium-denuded guinea-pig trachea with a pK(B) of 10.8, but had no effect on carbachol-induced contraction of the trachea even at 10(-6) M. These results indicate that FR167344 has the specific antagonistic activity against guinea-pig tracheal smooth muscle bradykinin receptors.

Morphological comparison and functional reconstitution of rat hepatic parenchymal cells on various matrices

Four types of materials, type I collagen coat (Coat), acid-soluble type I collagen gel (Hardgel), pepsin-treated acid-soluble type I collagen gel (Softgel), and an extract of extracellular matrix of the murine Engelbreth-Holm-Swarm sarcoma (Matrigel), were used as matrices to culture rat hepatic parenchymal cells, and their morphological changes and adhesion were compared to the matrices by electron microscopic observations. Hepatic parenchymal cells cultured on Coat and Hardgel were extended and flattened, whereas cells cultured on Softgel and Matrigel assembled and formed aggregates. Such aggregates consisted of several hepatic parenchymal cells, with a recognizable bile duct-like alveolus on the inside. Morphologically, the aggregates were more spherical on Matrigel and oval shaped on Softgel. Microvilli of the cell surface were parallel to the matrix on Matrigel, but invaded into the gel on Softgel. Subsequently, investigation into how these morphological features affected the liver-specific functions, including secretion of albumin and induction of P450 by 3-methylcholanthrene, demonstrated that a high level of liver function was maintained in a long-term culture in hepatic parenchymal cells on Softgel. These results suggest that hepatic parenchymal cell interactions were stronger with Softgel than with Matrigel, and that Softgel appears to closely mimic the in vivo environment.

Non-enzymatic, template-directed ligation of 2'-5' oligoribonucleotides. Joining of a template and a ligator strand

Decauridylate containing exclusively a 2'-5' phospho-diester bond ([2'-5']U10) served as a template for the synthesis of oligoadenylates [oligo(A)s] from the 5'-phosphorimidazolide of 2'-5' diadenylate (ImpA-2'p5'A). Joining of [2'-5']U10and ImpA2'p5'A also took place in substantial amounts to yield long-chain oligoribonucleotides in the template-directed reaction. An unusual CD spectrum ascribed to helix formation between [2'-5']U10and [2'-5'](pA)2was observed under the same conditions as that of the template-directed reaction. The 3'-5' linked decauridylate ([3'-5']U10) also promoted the template-directed synthesis of oligo(A)s from ImpA2'p5'A, but more slowly compared with [2'-5']U10. The results indicate that short-chain RNA oligomers with a 2'-5' phosphodiester bond could lead to longer oligoribonucleotides by template-directed chain elongation.

Pharmacological characterization of a nonpeptide bradykinin B2 receptor antagonist, FR165649, and agonist, FR190997

1. The nonpeptide bradykinin (BK) B2 receptor antagonist, FR165649 (8-[2,6-dichloro-3-[N-[(E)-4-(N-methylcarbamoyl)cinnamidoacetyl ]-N-methylamino]benzyloxy]-2-methylquinoline), and agonist, FR190997 (8-[2,6-dichloro-3-[N-[(E)-4-(N-methylcarbamoyl) cinnamidoacetyl]-N-methylamino]benzyloxy]-2-methyl-4-(2-pyridyl methoxy)quinoline) have been identified. These compounds have a common chemical structure, and the 2-pyridylmethoxy group is the only structural difference between them. 2. Both FR165649 and FR190997 displaced [3H]-BK binding to B2 receptors in guinea-pig ileum membranes, with an IC50 of 4.7 x 10(-10) M and 1.5 x 10(-9) M, respectively. They also displaced [3H]-BK binding to B2 receptors in human lung fibroblast IMR-90 cells, with an IC50 of 1.6 x 10(-9) M and 9.8 x 10(-10) M, respectively. 3. In guinea-pig isolated ileum-preparations, FR165649 had no agonistic effect on contraction and caused parallel rightward shifts of the concentration-response curves to BK on contraction. Analysis of the data produced a nominal pA2 value of 9.2+/-0.1 (n=5) and a slope of 1.4+/-0.1 (n=5). On the other hand, FR190997 induced concentration-dependent contraction of guinea-pig ilea with a pD2 of 7.9+/-0.2 and the contraction was inhibited by a specific peptide bradykinin B2 receptor antagonist, Hoe 140 (D-Arg-[Hyp3, Thi5, D-Tic7, Oic8]BK) in a non-competitive manner. 4. In IMR-90 cells, FR165649 had no agonistic effect on phosphatidyl inositol (PI) hydrolysis and caused parallel rightward shifts (approximately 200 fold shift at 10(-7) M) of the concentration-response curves to BK on PI hydrolysis. FR190997 induced concentration-dependent PI hydrolysis in IMR-90 cells with a pD2 of 8.4+/-0.1, and this effect was inhibited by Hoe 140. 5. These results indicate that FR165649 and FR190997 are, respectively, a potent bradykinin B2 receptor antagonist and agonist, and that the agonistic activity depends on the small part of the nonpeptide ligand. FR165649 and FR190997 may be useful tools for studying the relationship between ligands and receptors.

Synthesis and anti-HIV activity of phosphorothioate antisense DNA containing C-5 polyamine substituted 2'-deoxyuridine and/or acridine residues

Novel phosphorotioate DNAs (S-ODNs) bearing polyamine moiety at the C-5 position of 2'-deoxyuridine in place of certain thymidine residues and/or an acridine moiety at the 5'-terminus were prepared. The sequence of the S-ODNs is complementary to the rev region of HIV-1 mRNA. The duplexes consisted of the modified S-ODNs and the complementary DNA exhibited the enhanced stability compared to that consisted of the corresponding unmodified S-ODN and the complement. The improved antisense activity against HIV-1 was also observed for all modified S-ODNs.

Malignant fibrous histiocytoma originating from the chest wall: report of a case and collective review of cases

Malignant fibrous histiocytomas occur principally as a mass of the extremities, abdominal cavity, or retroperitoneum in adults. However, they only rarely occur in the chest wall. A rare case of primary malignant fibrous histiocytoma originating from the chest wall is herein presented. The 36 previously reported cases are also reviewed. Of the 32 patients who underwent a resection as the initial treatment, 10 (31.3%) had a local recurrence. Of the 37 patients with this disease, 9 (25.0%) had subsequent metastases. The majority of the deaths (36.1%) from this disease occurred within the first 12 months. The patients who undergo surgical and adjuvant therapy must therefore be monitored carefully by frequent examinations.

Synthesis of oligodeoxyribonucleotide containing novel C-5 reactive 2'-deoxyuridine derivative and its functional modification via post-synthetic technique

2'-Deoxyuridine derivatives bearing an activated ester at C-5 position were synthesized and was examined their use for the preparation of modified oligodeoxyribonucleotides (ODNs) by a post-modification method. The ODNs containing cyanomethyl ester at C-5 position of the deoxyuridine residue reacted easily with a primary amine of several functional molecules under the mild condition to give the corresponding modified ODNs.

Functional recovery of vision in regenerated optic nerve fibers

Retinal ganglion cells (RGCs) of adult mammals normally suffer from retrograde cell death after optic nerve section. However, with transplantation of a segment of peripheral nerve (PN), their axons can regenerate and regrow through the graft. When properly guided, the regenerated axons make functional synapses with the target cells in the superior colliculus. Two months after PN graft we studied the number and morphology of RGCs with regenerated axons in adult cats. Number of regenerated RGCs was a few percent of the total population and, among various RGC types, alpha cells revealed the greatest ability for axonal regeneration and ON-center RGCs tended to regenerate better than OFF-center cells. While dendritic field dimension of RGCs with regenerated axons was mostly preserved, their regenerated axons were thinner than normal optic axons and mostly unmyelinated. The RGCs with regenerated axons revealed normal physiological properties in response to visual stimuli, and were classifiable into Y, X or W cells. In accordance with morphological results, Y cells (morphological alpha cells) were most frequently sampled. In hamsters and rats it has been shown that the animals with reconstructed retinocollicular pathway by the PN graft reveal behavioral recovery of visual function. However, in the cat, trials are still in progress to reconstruct the retinogeniculate pathway. The present status of researches on optic nerve regeneration of adult mammals using the PN graft is reviewed, and some future directions discussed.

Somatic frameshift mutations in DNA mismatch repair and proapoptosis genes in hereditary nonpolyposis colorectal cancer

An exacerbated genomic instability at simple repeated sequences characterizes cancer of the microsatellite mutator phenotype (MMP). The majority of hereditary nonpolyposis colon cancers (HNPCCs) and about 15% of nonselected ("sporadic") gastrointestinal tumors belong to the MMP pathway of tumorigenesis. Colorectal MMP+ and MMP- tumors exhibit fundamental differences in genotype and phenotype. We have shown previously that "sporadic" MMP+ colon cancers exhibit a paradoxical low incidence of somatic mutations in the p53 tumor suppressor gene and the c-K-ras proto-oncogene. On the other hand, gastrointestinal MMP+ cancers frequently harbor frameshift mutations in genes containing mononucleotide repeats. These include the cell growth regulator gene TGFbetaRII and the proapoptotic gene BAX. We have also recently shown the frequent presence of frameshift mutations in (A)8 and (C)8 tracts within the hMSH3 and hMSH6 DNA mismatch repair genes in sporadic colon cancer of the MMP. Here, we describe the nearly identical incidence of somatic frameshift mutations in these genes in a panel of 27 HNPCC MMP+ cancers: 52% in hMSH3 and BAX and 33% in hMSH6. In contrast, no mutations in any of these genes were found in 10 MMP- cancers of HNPCC patients. These results show that the multistep model for the unfolding of the MMP also applies to HNPCC and further illustrate the importance of the escape from apoptosis in the MMP pathway for gastrointestinal cancer. They also underscore the differences in genotype between tumors with and without enhanced microsatellite instability and the similarities in genotype between tumors of the MMP regardless of their hereditary or sporadic nature.

Caspases are activated in a branched protease cascade and control distinct downstream processes in Fas-induced apoptosis

Two novel synthetic tetrapeptides, VEID-CHO and DMQD-CHO, could selectively inhibit caspase-6 and caspase-3, respectively. We used these inhibitors to dissect the pathway of caspase activation in Fas-stimulated Jurkat cells and identify the roles of each active caspase in apoptotic processes. Affinity labeling techniques revealed a branched protease cascade in which caspase-8 activates caspase-3 and -7, and caspase-3, in turn, activates caspase-6. Both caspase-6 and -3 have major roles in nuclear apoptosis. Caspase-6 cleaves nuclear mitotic apparatus protein (NuMA) and mediates the shrinkage and fragmentation of nuclei. Caspase-3 cleaves NuMA at sites distinct from caspase-6, and mediates DNA fragmentation and chromatin condensation. It is also involved in extranuclear apoptotic events: cleavage of PAK2, formation of apoptotic bodies, and exposure of phosphatidylserine on the cell surface. In contrast, a caspase(s) distinct from caspase-3 or -6 mediates the disruption of mitochondrial membrane potential (permeability transition) and the shrinkage of cytoplasm. These findings demonstrate that caspases are organized in a protease cascade, and that each activated caspase plays a distinct role(s) in the execution of Fas-induced cell death.

Helical structure formation between complementary oligonucleotides. Minimum chain length required for the template-directed synthesis of oligonucleotides

Helix formation between various combinations of 3'-5' linked oligoribouridylates and oligoriboadenylates from dimer to dodecamer has been studied to gain information on the chain-length requirement for the template-directed condensation of oligoribonucleotides. We have measured the helix formation under high oligoribonucleotide concentration in the presence of magnesium ion at 0-50 degrees C by UV or CD, as many model processes of oligoribonucleotides replication have been carried out under such conditions. Adenylic acid, (pA), diadenylic acid, (pA)2, or triadenylic acid, (pA)3, forms a helix with poly(U) or oligo(U) with a chain length of more than eight. On the other hand, neither uridylic acid, (pU), nor diuridylic acid. (pU)2, can form a helix with oligo(A) or poly(A). Triuridylic acid, (pU)3, or the longer oligo(U) forms a helix with oligo(A) with a chain length of over six. The results suggest that a trimer is the minimum unit as an incorporating nucleotide for conducting any set of nonenzymatic template-directed synthesis, A --> U and U --> A, as the nonenzymatic template-directed condensation of oligoribonucleotides correlates well with the results of helix formation of complementary oligoribonucleotides. We have further found the partial helix formation between 2'-5' linked decauridylate, (pU)10, and pA or 2'-5' linked (pA)2 at 0 degrees C, which indicates the possibility of the template activity of long 2'-5' linked oligonucleotides for the nonenzymatic oligonucleotide synthesis.

Effects of a nonpeptide bradykinin B2 receptor antagonist, FR167344, on different in vivo animal models of inflammation

1. The effects of a novel, potent and orally active nonpeptide bradykinin B2 receptor antagonist, FR167344 (N-[N-[3-[(3-bromo-2-methylimidazo[1,2-a]pyridin-8-yl)oxymethyl]-2 ,4-dichlorophenyl]-N-methylaminocarbonylmethyl]-4-(dimethylamin ocarbonyl) cinnamylamide hydrochloride) were tested in three different in vivo models of inflammation. 2. Oral administration of FR167344 inhibited carrageenin-induced paw oedema in rats (carrageenin: 1%, 0.1 ml per animal, intraplantar), with an ID50 of 2.7 mg kg(-1) at 2 h after carrageenin injection (n=10 or 11). 3. Oral administration of the compound also inhibited kaolin-induced writhing (kaolin: 250 mg kg(-1), i.p.) in mice, with ID50 of 2.8 mg kg(-1) in 10 min writhing and 4.2 mg kg(-1) in 15 min writhing (n=19 or 20). 4. Additionally, oral administration of FR167344 inhibited caerulein-induced pancreatic oedema with an ID50 of 13.8 mg kg(-1) as well as increases in amylase and lipase of blood samples with ID50 of 10.3 and 7.4 mg kg(-1), respectively, in rats (n=10). 5. These results show that FR167344 is an orally active, anti-inflammatory and anti-nociceptive agent in carrageenin-induced paw oedema, kaolin-induced writhing and caerulein-induced pancreatitis. FR167344 may have therapeutic potential against inflammatory diseases by oral administration and it may be a useful tool for studying the involvement of B2 receptors in various in vivo models of inflammation.

Frameshift somatic mutations in gastrointestinal cancer of the microsatellite mutator phenotype

An exacerbated genomic instability characterizes hereditary and sporadic gastrointestinal cancer of the microsatellite mutator phenotype (MMP), generating somatic frameshift mutations in genes containing mononucleotide repeats. We have recently shown that approximately 50, 40, and 30% of MMP+ colon tumors harbor frameshift mutations in (G)8, (A)8, and (C)8 tracks within the proapoptotic gene BAX and the hMSH3 and hMSH6 DNA mismatch repair genes, respectively. Here we report a higher incidence of frameshift mutations in these 3 genes in a panel of 25 MMP+ gastric adenocarcinomas: 64% in BAX and hMSH3, and 52% in hMSH6. These results support a multiple mutator gene model for the stepwise unfolding of the MMP and further illustrate the importance of the escape from apoptosis in gastrointestinal cancer. The tumor suppressor role played by BAX is also supported by the finding of other somatic BAX mutations, including recurrent missense mutations, not only in gastrointestinal cancer of the MMP but also in gastrointestinal cancer without the MMP.

Survival of axotomized retinal ganglion cells in adult mammals

As a nature of central neurons, retinal ganglion cells (RGCs) of adult mammals cannot regenerate spontaneously, but rather, degenerate retrogradely after optic nerve (ON) transection. Recent studies have clarified that some RGCs survive axotomy and regrow their axons through the graft when the peripheral nerve is transplanted to the cut stump. However, the numbers of regenerated fibers are still quite small and a great majority of RGCs die after axotomy. Studies on the rodent and cat retinas have revealed that vulnerability to axotomy differs among RGC types. Especially in the cat retina, X/beta cells are more vulnerable to axotomy than other cells. Several neurotrophic factors such as brain-derived neurotrophic factor (BDNF) and neurotrophin-4 or 5 (NT-4/5) are effective to rescue RGCs from retrograde cell death, and promote growth of intraretinal axons. Localization of their receptors is also demonstrated in RGCs. On the other hand, evidence has been accumulated that regenerated ON fibers reform functional synapses with central visual neurons and thereby axotomized RGCs survive longer. These reformed retino-collicular synapses enabled the animals to recover the ability of light-dark discrimination.

An approach to prebiotic synthesis of alpha-oligoribonucleotides and description of their properties: selective advantage of beta-RNA over alpha-RNA

Oligomerization of alpha-adenosine 5'-phosphorimidazolide (alpha-ImpA) has been done in an aqueous solution using a uranyl-ion catalyst or a poly(U) template as a model process of prebiotic synthesis of RNA with alpha-glycosidic linkage. alpha-Oligoriboadenylates up to hexamer were formed from alpha-ImpA by the uranyl-ion catalyst. 3'-5' Linkage was mainly formed in the oligomerization. The poly(U) template mediated the oligomerization of alpha-ImpA, but to a very low extent. The yield and chain length of the resulting alpha-oligomers were far lower than those of the corresponding beta-oligomer formation under the same conditions. Physico-chemical properties of alpha-oligoriboadenylates are presented along with those of the corresponding beta-oligoriboadenylates. The results indicate that beta-RNA is more advantageous than alpha-RNA from the points of their synthesis and properties.

Pharmacological characterization of a novel, orally active, nonpeptide bradykinin B2 receptor antagonist, FR167344

To investigate the pathophysiological role of bradykinin and to develop a drug for inflammatory diseases, we discovered an orally active, nonpeptide bradykinin B2 receptor antagonist, FR167344, N-[N-[3-[(3-bromo-2-methylimidazo[1,2-a]pyridin-8-yl)oxymethyl]-2, 4dichlorophenyl]-N-methylaminocarbonylmethyl]-4-(dimethyl aminocarbonyl) cinnamylamide hydrochloride. This compound competitively displaced [3H]bradykinin binding to bradykinin B2 receptors present in guinea-pig ileum membrane with an IC50 value of 6.6 X 10(-10) M. In isolated guinea-pig ileum preparations, it also antagonized bradykinin-induced contraction with a pA2 value of 9.3. In human lung fibroblast IMR-90 cells, FR167344 displaced [3H]bradykinin binding to human bradykinin B2 receptors with an IC50 value of 1.3 X 10(-8) M, but not [3H]des-Arg10-kallidin binding to human bradykinin B1 receptors. In vivo, oral administration of FR167344 inhibited bradykinin-induced bronchoconstriction in guinea pigs and the bradykinin-induced hypotensive response for 6 h in rats. These results show that FR167344 is a potent, selective, orally active and long acting bradykinin B2 receptor antagonist.