The G1/S boundary-specific enhancer of the rat cdc2 promoter.

Multiple species of G1 cyclins and cyclin-dependent kinases are induced sequentially during G1 phase, and the expression of cyclin A and cdc2 genes is subsequently induced at the G1/S boundary. To analyze the mechanism of cdc2 promoter activation, the 5'-flanking region of the rat cdc2 gene was isolated and its structural features were characterized. The highly conserved sequence between human and rat cdc2 genes is present in the basal promoter region from positions -183 to -122, which contains the E box, SpI, and E2F motifs. The expression of 5' sequential deletion derivatives of the promoter fused to luciferase cDNA in rat 3Y1 cells revealed the presence of the enhancer element. The presumed enhancer region was further analyzed by the introduction of base substitutions and by the formation of DNA-protein complexes with cell extracts prepared at various times during the G1-to-S-phase progression. These analyses revealed that the enhancer sequence, AAGTTACAAATA, located from -276 to -265, confers strong inducibility on the basal promoter at the G1/S boundary. The base substitutions introduced into the motifs of transcription factors indicated that the E2F motif is essential for the enhancer-dependent activation of the cdc2 promoter at the G1/S boundary. Electrophoretic mobility shift assays and DNase I footprinting showed that a factor which interacts with the enhancer element is induced late in G1 phase.

Nucleotide sequence of an alternative glucoamylase-encoding gene (glaB) expressed in solid-state culture of Aspergillus oryzae.

The DNA (glaB) and a cDNA-encoding glucoamylase produced in solid-state culture of Aspergillus oryzae were cloned using oligodeoxyribonucleotide probes derived from internal amino acid sequences of the enzyme. Comparison of the nucleotide sequences of a genomic DNA fragment with its cDNA showed the glaB gene carried three exons interrupted by two introns and had an open reading frame encoding 493 aa residues. The 5'-flanking region had a TATA box at nt -87 from the start codon and two putative CAAT sequences at nt -276 and -288. The glaB gene shared 57% homology at the aa level with the glaA gene which was cloned previously from A. oryzae. Interestingly, the glucoamylase encoded by the glaB gene had no C-terminal domain such as that proposed to have starch binding activity in Aspergillus glucoamylases. Introduction of cDNA of the glaB gene to Saccharomyces cerevisiae caused the secretion of active glucoamylase to culture medium and introduction of the glaB gene to A. oryzae increased glucoamylase productivity in solid-state culture. Northern blot analysis showed the glaB gene was expressed in solid-state culture, but not in submerged culture.

Sugar-modified nucleosides in past 10 years, a review.

In the search for effective, selective, and nontoxic antiviral and antitumour agents, a variety of strategies have been devised to design nucleoside analogs. These strategies have involved several formal modifications of the naturally occurring nucleosides, especially, alteration of the carbohydrate moiety. Since the naturally occurring purine nucleoside analog oxetanocin A and its derivatives have been found to be effective as anti-HIV-1 and anti-herpes virus agents in 1986, the syntheses of different types of sugar-modified nucleoside analogs have been reported. In this review we will give an overview of the sugar-modified nucleosides synthesized since the late 1990 according to their structural types along with the synthetic routes of some selected nucleosides.

Infantile neuroaxonal dystrophy: perinatal onset with symptoms of diencephalic syndrome.

In a neonatal case of infantile neuroaxonal dystrophy, there was emaciation, nystagmus, and endocrinologic disorder suggesting the diencephalic syndrome. At autopsy, spheroid bodies were widely disseminated, particularly in the hypothalamus, infundibulum, and neurohypophysis. The pathologic process may have started in utero.

A tetrazolium method for staining peroxidase labels in blotting assays.

A sensitive staining method of horseradish peroxidase-labeled immunoglobulins on nitrocellulose membrane was established by employing a reaction chain leading to formazan formation with phenol as a substrate of peroxidase and NADH as a hydrogen donor to reduce nitro blue tetrazolium. Higher concentrations of NADH relative to phenol were necessary to increase the intensity of staining and to ensure a wide dose-response range of color production with respect to the applied enzyme activities. By an optimized tetrazolium method in combination with antibody-affinity blotting, as low as 4 ng/ml alpha-fetoprotein was detected and 3-4-fold greater color intensities in a working assay range as compared with those of existing methods were obtained. The present technique of peroxidase staining may prove to have a wide application for the enzyme immunoassay using blotting modalities.

Allomyrina dichotoma lectin-nonreactive alpha-fetoprotein in hepatocellular carcinoma and other tumors: comparison with Ricinus communis agglutinin-I.

Allomyrina dichotoma lectin (allo A) with a specificity to beta-D-galactose was used to fractionate human alpha-fetoprotein (AFP) by affinity electrophoresis. AFP from cord sera and serum of a patient with fulminant hepatitis showed single bands with a high affinity for allo A. Some patients with hepatocellular carcinoma and patients with gastric cancer and yolk sac tumor had two additional AFP bands, one weakly reactive and the other nonreactive with allo A. Patterns of AFP bands obtained with Ricinus communis agglutinin-I (RCA-I) and erythroagglutinating phytohemagglutinin from Phaseolus vulgaris were entirely different from those obtained with allo A. Of the two common bands reactive with RCA-I, the weakly reactive one was relatively intense in some malignant patients and the strongly reactive one was detected in patients with extrahepatic tumors. Thus, affinity electrophoresis with those lectins provides a potentially useful adjunct for the discrimination between benign and malignant conditions with increased serum levels of AFP.

Distinct molecular species of human alpha-fetoprotein due to differential affinities to lectins.

Resolution of human alpha-fetoprotein (AFP) into four distinct molecular species was demonstrated by a combination of two affinity chromatographies with crossed-immuno-affino-electrophoresis (CIAE) using concanavalin A (Con A) and Lens culinaris hemagglutinin (LcH)-A and LcH-B as affinity media. Of the four AFPs, AFP1 had no affinity for Con A, LcH-A, or LcH-B; AFP2 showed a high affinity for Con A, a low affinity for LcH-A, and an intermediate affinity for LcH-B (or a low affinity, depending on the lot of LcH-B preparations used); AFP3 revealed strong affinities for all of the three lectins; and AFP4, a trace component of hepatoma AFP in the present study, showed no interaction with Con A, but a definite interaction with LcH-A or LcH-B. These results were based on the determination of dissociation constants (Kd) of AFP-lectin complex by CIAE on isolated preparations of the three major hepatoma AFPs. These AFPs had identical electrophoretic mobilities of 0.86-0.87 (relative to human albumin) in the absence of lectins. The calculated mobilities of AFP2 and AFP3 were both reduced to 0.50-0.58 by saturation with lectins, but these two AFPs were clearly separated by 1 mg/ml LcH-A or LcH-B because of their large differences in Kd.

Dopamine D2 receptor-mediated antioxidant and neuroprotective effects of ropinirole, a dopamine agonist.

Recent information suggests that free radicals are closely involved in the pathogenesis and/or progression of Parkinson's disease (PD). High-dose levodopa therapy has been suggested to increase oxidative stress, thereby accelerating the progression of PD. Based on this viewpoint, free radical scavenging, antioxidant and neuroprotective agents which may prevent the progression of PD have recently attracted considerable attention. For example, ergot derivative dopamine (DA) agonists have been reported to scavenge free radicals in vitro and show a neuroprotective effect in vivo. Non-ergot DA agonists have also recently been used in the treatment of PD despite the lack of substantial evidence for any free radical scavenging activity or antioxidant activity. The present study was conducted to assess the in vitro free radical scavenging and antioxidant activities of ropinirole, a non-ergot DA agonist, as well as its glutathione (GSH), catalase and superoxide dismutase (SOD) activating effects and neuroprotective effect in vivo. Ropinirole scavenges free radicals and suppresses lipid peroxidation in vitro, but these activities are very weak, suggesting that the antioxidant effect of ropinirole observed in vitro may be a minor component of its neuroprotective effect in vivo. Administration of ropinirole for 7 days increased GSH, catalase and SOD activities in the striatum and protected striatal dopaminergic neurons against 6-hydroxydopamine (6-OHDA) in mice. Pre-treatment with sulpiride prevented ropinirole from enhancing striatal GSH, catalase and SOD activities and abolished the protection of dopaminergic neurons against 6-OHDA. Our findings indicate that activation of GSH, catalase and SOD mediated via DA D2 receptors may be the principal mechanism of neuroprotection by ropinirole.

Keratin and involucrin expression in discoid lupus erythematosus and lichen planus.

In the present study, keratin and involucrin expression were studied in cutaneous lesions of discoid lupus erythematosus and lichen planus in order to gain a better understanding of the abnormal differentiation or maturation of the epidermal cells in these dermatoses. Ten specimens each from discoid lupus erythematosus and lichen planus were analyzed by immunohistochemical techniques, using a panel of monoclonal antikeratin antibodies and polyclonal anti-involucrin antibody, and five specimens each were analyzed by one- and two-dimensional gel electrophoresis and immunoblot analysis using three antikeratin antibodies. No significant difference was found between the dermatoses. The expression of differentiation-specific keratins showed a similar pattern to that in normal epidermis, and involucrin was expressed even in the lower part of the stratum spinosum. Keratins 6 and 16, which are characteristic markers of hyperproliferative states, and keratin 17 were detected in nonhyperproliferative and atrophic epidermis with hydropic degeneration and inflammatory infiltrates in the dermis. These results suggest that expression of keratins 6, 16 and 17 in discoid lupus erythematosus and lichen planus may reflect a wound healing response to the damage to the basal cell layer, or may be under the control of cytokines produced by infiltrating inflammatory cells in the dermis.

Electrophoresis and electro-affinity transfer with specific antibodies to alpha-fetoprotein for detection of circulating immune complexes of alpha-fetoprotein.

A combination of agarose gel electrophoresis and a newly developed technique of electro-affinity transfer was applied to the detection of circulating immune complexes of human alpha-fetoprotein (AFP) and anti-AFP. After electrophoretic transfer to nitrocellulose membrane, to which affinity-purified polyclonal horse antibodies to human AFP were bound, the membranes were treated with or without rabbit immunoglobulins to human AFP, followed by overlaying with horseradish peroxidase-labeled goat anti-rabbit IgG for color development. Artificial complexes formed in vitro from human AFP and rabbit anti-AFP were clearly separated from free AFP by the agarose electrophoresis. The complexes were stained 20-40% as dark as the equivalent amount of free AFP by treatment with rabbit anti-AFP, and 10-20% as dark without the antibody treatment over a wide range of antigen-antibody ratios.

Abnormal distribution of epidermal protein antigens in psoriatic epidermis.

The immunohistochemical distribution of the epidermal proteins filaggrin, involucrin, and cytokeratins is characteristic in normal epidermis. This distribution may change as a result of malignant transformation or abnormal differentiation. The present study was conducted to determine the patterns of reactivity of psoriatic epidermis to antibodies against various epidermal proteins and to clarify abnormal differentiation or maturation of the keratinocytes in psoriatic epidermis. Anti-human filaggrin, anti-human involucrin, and twelve kinds of anti-cytokeratin antibodies were used in this study. Cryostat or paraffin-embedded sections were stained with these antibodies by the avidin-biotin peroxidase technique. The epidermis of the noninvolved skin of patients with psoriasis vulgaris showed the distribution seen in normal skin. However, involved psoriatic skin revealed little or no reaction in the stratum corneum or in the granular layer with the anti-filaggrin antibody. Cells positively staining with anti-involucrin antibody paradoxically appeared in the lower cell layers of involved psoriatic epidermis. An anti-keratin antibody, AE1, stained suprabasal cells in involved psoriatic epidermis, although this antibody selectively stained epidermal basal cells in normal skin. The other anti-keratin antibodies, especially KL1, PKK1, and a polyclonal anti-keratin antibody, were less reactive with involved psoriatic skin than with normal skin. These observations suggest that the maturation pathway of keratinocytes in active psoriatic lesions differs qualitatively from that in normal epidermis.

Monoclonal antibody OKB19, reactive with a B-lymphoid differentiation antigen (CD19), binding to basal layer keratinocytes of normal human skin.

Monoclonal antibody (moAB) OKB19 reacts with CD19 antigen, which is the broadest lineage-specific surface marker on B-lymphocytes. In frozen tissue sections, using an immunohistochemical technique, the OKB19-positive cells in the basal layer were sharply demarcated from the negative suprabasal layers. In normal hair follicles, the OKB19 reactivity was also confined to one layer of the dermal side of the outer root sheath. However, this reactivity gradually disappeared in the lower areas. The inner surface of the lumina in the eccrine duct was weakly stained with OKB19. The basal keratinocytes were also stained with OKB19 in the lesional epidermis of the various dermatoses examined in this study, when the basal keratinocytes remained unaffected. Even in the hyperproliferative state of psoriasis, the OKB19 reactivity was confined to the basal layer. Several kinds of tumor cells derived from the skin were not stained with OKB19. No labeling was seen even in the basaloid cells of basal cell carcinoma, which are morphologically similar to basal keratinocytes. B4 and Leu-12, other monoclonal antibodies reacting with CD19, did not recognize any keratinocytes in the normal human skin. MoAB OKB19, therefore, reacts with an antigen present on basal keratinocytes and provides a probe for the isolation of the basal keratinocyte subpopulation. Thus, this antibody should be useful in studies of not only B-lymphocyte differentiation, but also normal and aberrant differentiation of the epidermal keratinocytes.

A case of cutaneous malignant fibrous histiocytoma.

A 54-year-old Japanese man with cutaneous malignant fibrous histiocytoma on the back is reported. He not only had a past history of thyroid cancer 1 year prior to the onset of the skin tumor, but also had simultaneous bladder cancer. Despite the early, wide resection, the prognosis was rapid and progressive. Histologically, the primary lesion of the skin tumor was difficult to differentiate from dermatofibrosarcoma protuberans; however, the recurrent and the metastatic lesions changed in appearance.

[Drug eruption due to iohexol (Omnipaque)].

Disseminated maculopapular eruption developed 5 to 6 days after the administration of Iohexol (Omnipaque) for the drip infusion pyelography in three cases. The skin tests clearly demonstrated that Iohexol was the causative factor, and other Iodinated contrast mediums and Trometamol which contained in Omnipaque as stabilizing agent were negative skin tests.

Immunohistochemical localization of keratins and involucrin in solar keratosis and Bowen's disease.

The present study was conducted to determine the patterns of immunohistochemical characterization of keratin (K) and involucrin in solar keratosis and Bowen's disease in order to clarify the abnormal differentiation or maturation of the tumor cells in these precancerous epithelial dermatoses. Seventeen human anti-cytokeratin antibodies and an anti-involucrin antibody were used to examine 15 cases of solar keratosis and 18 cases of Bowen's disease. Formalin-fixed and paraffin-embedded sections were stained with these antibodies by the avidin-biotin-peroxidase technique. In solar keratosis, keratin and involucrin distribution was similar to that in normal epidermis, whereas in Bowen's disease the keratin distribution varied among individual cases. The dyskeratotic cells in Bowen's disease showed a reduction or loss of staining with these antibodies, and they were occasionally positive for keratin 19. These observations suggest that there is a difference in keratin and involucrin expression between solar keratosis and Bowen's disease and that the atypical cells of Bowen's disease exhibit a diversity of differentiation.

Synthesis of 2',3'-dideoxy-3'-C-(hydroxymethyl)-4'-thiopentofuranosyl nucleosides as potential antiviral agent.

1-O-Acetyl-2,3-dideoxy-3-C-(hydroxymethyl)-4-thiofuranose derivative was synthesized from (S,S)-1,4-bis(benzyloxy)-2,3-epoxybutane derived from (+)-diethyl L-tartrate and the enantiomerically pure (E)-5-(2-bromovinyl)-1-[2',3'-dideoxy-3'-C-(hydroxymethyl)-beta-D-4'- thiopentofuranosyl]uracil 4 was obtained via coupling of silylated uracil followed by palladium-mediated coupling of methyl acrylate.

Synthesis and biological activity of unusual nucleosides having 3,4-bis(hydroxymethyl) thietane ring as a sugar moiety.

The enantiomerically pure synthesis of 9-[(2'S, 3'S)-bis(hydroxymethyl)thietan-1'-yl]adenine 2,3'-thio analog of oxetanocin A, was achieved via coupling of silylated 6-chloropurine and sulfoxide 16 under Pummerer reaction conditions.