RESUMEN
Recent advances in the treatment of hepatocellular carcinoma (HCC) have prolonged patient survival. However, the number of patients with bone metastases identified during follow-up examinations has increased. Tc-99m Sn-N-pyridoxy-5-methyltryptophan (Tc-99m PMT) has been reported to accumulate at a high rate in HCC lesions and bone metastases. In the patient described here, whole-body scintigraphy showed accumulation of DTPA galactosyl human serum albumin (Tc-99m GSA) and Tc-99m PMT in bone metastases from HCC. The authors suggest that asialoglycoprotein receptors may be present in bone metastases from well-differentiated HCC. Tc-99m GSA whole-body imaging can be used to detect bone metastases from HCC and to evaluate hepatic reserve.
Asunto(s)
Albúminas , Neoplasias Óseas/diagnóstico por imagen , Neoplasias Óseas/secundario , Carcinoma Hepatocelular/diagnóstico por imagen , Carcinoma Hepatocelular/secundario , Neoplasias Hepáticas/patología , Compuestos de Organotecnecio , Radiofármacos , Medronato de Tecnecio Tc 99m/análogos & derivados , Triptófano/análogos & derivados , Humanos , Masculino , Persona de Mediana Edad , CintigrafíaRESUMEN
The effects of 4-(4-fluorophenyl)-2-methyl-6-(5-piperidinopentyloxy) pyrimidine hydrochloride (NS-7), a novel neuroprotective compound, on the voltage-sensitive sodium channels (VSSC) were examined in the rat brain and cardiac myocytes. NS-7 inhibited [3H]batrachotoxinin A 20 alpha-benzoate (BTX) binding (neurotoxin receptor site 2) in brain membranes with a Ki value of 1 microM, while the compound was less effective in the cardiac myocytes (Ki = 13 microM). Aconitine, on the other hand, inhibited [3H]BTX binding to brain membranes and cardiac myocytes with the same potency. In contrast. NS-7 had no affinity for [3H]saxitoxin binding in brain (neurotoxin receptor site 1). In superfused slices of the rat cerebral cortex, NS-7 inhibited the veratridine (5 microM)-evoked glutamate release in a concentration-dependent manner, the IC50 value of which was 7.7 microM, whereas the compound showed a weak and not significant suppression of KCl-evoked glutamate release. The tissue concentrations of NS-7 in the rat cerebral cortex and heart were 89 and 28 nmole/g tissue, respectively, 5 min after its intravenous injection (8 mg/kg). Furthermore, in the cerebral cortex, NS-7 distributed preferentially to the membrane-enriched synaptosomal fraction. Since neurotoxin receptor site 2 is located in the transmembrane region of the VSSC moiety, the channel function may be substantially inhibited by a peripheral administration of NS-7. These results suggest that the blockade of neurotoxin receptor site 2 of VSSC in the brain contributes to the neuroprotective action of NS-7.
Asunto(s)
Corteza Cerebral/efectos de los fármacos , Fármacos Neuroprotectores/farmacología , Pirimidinas/farmacología , Canales de Sodio/efectos de los fármacos , Aconitina/farmacología , Análisis de Varianza , Animales , Batracotoxinas/metabolismo , Unión Competitiva , Corteza Cerebral/metabolismo , Relación Dosis-Respuesta a Droga , Ácido Glutámico/metabolismo , Corazón/efectos de los fármacos , Inyecciones Intravenosas , Masculino , Miocardio/citología , Miocardio/metabolismo , Fármacos Neuroprotectores/administración & dosificación , Neurotoxinas/metabolismo , Cloruro de Potasio/farmacología , Pirimidinas/administración & dosificación , Pirimidinas/sangre , Pirimidinas/metabolismo , Ratas , Ratas Wistar , Saxitoxina/metabolismo , Canales de Sodio/metabolismo , Sinaptosomas/efectos de los fármacos , Sinaptosomas/metabolismo , Veratridina/farmacologíaRESUMEN
The effect of a novel cognition enhancer [(+)-5-oxo-D-prolinepiperidinamide monohydrate] (NS-105) on cAMP formation was investigated in both slices and membranes of the rat cerebral cortex. NS-105 (10(-8)-10(-6) M) inhibited forskolin-stimulated cAMP formation in membranes, however, the compound significantly enhanced the cAMP formation in pertussis toxin-pre-treated membranes, an action that was abolished by cholera toxin. In contrast, in digitonin-permeabilized membranes, NS-105 had no influence on Mn2+-stimulated cAMP formation. Both of the inhibitory and facilitatory actions of NS-105 on cAMP formation were mimicked by a metabotropic glutamate receptor (mGluR) agonist (1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid (1S,3R-ACPD) and an adrenergic alpha2 agonist UK-14,304, and blocked by a mGluR antagonist 2-amino-3-phosphonopropanoate but not by an alpha2 antagonist yohimbine. In cortical slices, NS-105 (10(-8)-10(-7) M) inhibited forskolin-stimulated cAMP accumulation but enhanced isoproterenol-stimulated cAMP accumulation, as did by a GABA(B) agonist (-)baclofen. On the other hand, (-)baclofen, while it significantly inhibited cAMP accumulation in slices, did no longer inhibit cAMP accumulation, when treated with NS-105 (10(-8)-10(-5) M). Similarly, (-)baclofen-induced inhibition of the cAMP accumulation was reversed by 1S,3R-ACPD and UK-14,304. NS-105 (10(-6)) increased [35S]GTPgammaS binding in the intact but not digitonin-permeabilized cortical membranes, as produced by UK-14,304, although the compound (10(-9)-10(-3) M) had no influence on various neurotransmitter receptor bindings, including alpha2 receptors. These results suggest that NS-105 modulates adenylate cyclase activity by stimulating mGluRs which might coupled to both Gi/Go and Gs.
Asunto(s)
Adenilil Ciclasas/metabolismo , Corteza Cerebral/metabolismo , Cognición , Proteínas de Unión al GTP/metabolismo , Piperidinas/farmacología , Prolina/análogos & derivados , Receptores de Glutamato Metabotrópico/fisiología , Toxina de Adenilato Ciclasa , Agonistas alfa-Adrenérgicos/farmacología , Alanina/análogos & derivados , Alanina/farmacología , Animales , Baclofeno/farmacología , Tartrato de Brimonidina , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo , Corteza Cerebral/efectos de los fármacos , Toxina del Cólera/farmacología , Colforsina/farmacología , AMP Cíclico/metabolismo , Cicloleucina/análogos & derivados , Cicloleucina/farmacología , Antagonistas de Aminoácidos Excitadores/farmacología , Guanosina 5'-O-(3-Tiotrifosfato)/metabolismo , Técnicas In Vitro , Isoproterenol/farmacología , Cinética , Masculino , Manganeso/farmacología , Toxina del Pertussis , Prolina/farmacología , Quinoxalinas/farmacología , Ratas , Ratas Wistar , Receptores de Neurotransmisores/efectos de los fármacos , Receptores de Neurotransmisores/fisiología , Factores de Virulencia de Bordetella/farmacología , Yohimbina/farmacologíaRESUMEN
We have previously found that a cognition enhancer [(+)-5-oxo-D-prolinepiperidinamide monohydrate] (NS-105) reversed the inhibition of cyclic AMP formation induced by the GABA(B) receptor agonist baclofen. The GABA(B) receptor has been implicated in the pathophysiology of depressive illness. The present experiment was designed to evaluate the antidepressant activity of NS-105 in the forced swimming and learned helplessness tests in rats. NS-105 (1-100 mg/kg, p.o.) significantly decreased immobility time in the forced swimming test, an effect similar to that of desipramine. Repeated administration of NS-105 also reversed the failure to escape in the shuttle-box test of rats previously exposed to inescapable footshock. Biochemical data showed that repeated administration of NS-105 increased the number of GABA(B) receptors in rat cerebral cortex without affecting the binding properties of beta-adrenoceptors and 5-HT2 receptors. In contrast to other antidepressants, NS-105 did not inhibit monoamine uptake in vitro, nor did it change monoamine concentrations in brain tissues or extracellular fluids. These findings suggest that NS-105, which lacks an effect on monoaminergic systems, has potent antidepressant activity, which may involve up-regulation of GABA(B) receptors after repeated administration.
Asunto(s)
Antidepresivos/farmacología , Corteza Cerebral/efectos de los fármacos , Trastorno Depresivo/tratamiento farmacológico , Piperidinas/farmacología , Prolina/análogos & derivados , Receptores de GABA-B/metabolismo , Animales , Corteza Cerebral/metabolismo , Masculino , Microdiálisis , Norepinefrina/metabolismo , Prolina/farmacología , Ratas , Ratas Wistar , Receptores Adrenérgicos beta/metabolismo , Receptores de Serotonina/metabolismo , Serotonina/metabolismo , Sinaptosomas/metabolismoRESUMEN
Specific interaction of N-octadecanoyl-N-phenylhydroxylamine (ODPHA) and Ga3+ was evaluated by means of the L-B technique. The monolayer of ODPHA on a subphase containing Ga3+ and/or Al3+ was stable. Limiting areas of monolayer of ODPHA on the subphases are increased with pH of the subphase and reach constant values at certain pHs, 2.5 (on the Ga3+ solution) and 4.5 (on the Al3+ solution), respectively. The surface pressure-area isotherm for ODPHA on the Ga3+/Al3+ solution containing a 388-fold amount of Al3+ at pH 2.4 was similar to that for ODPHA on the Ga3+ solution at the same pH. A microporous polymeric membrane impregnating ODPHA showed a selective separation of Ga3+ from a solution containing a 388-fold amount of Al3+ at pH 2.4. The separation factor toward Ga3+ reached over 300.
RESUMEN
The synthesis of an oligodeoxynucleotide (ODN) modified with 2-methoxy-6-chloro-9-aminoacridine (Acr) at an abasic site is described. A stereochemically defined aminodiol, L-threoninol, was used to serve as artificial abasic nucleoside. The molecule was modified so as to be suitable for the standard phosphoramidite method and was incorporated into the interior of an ODN. In addition, N-hydroxysuccinimidyl N-[9-(6-chloro-2-methoxy)acridinyl]-6-aminocaproate has been synthesized for postsynthetic modification of the amino substrate of the L-threoninol moiety in the ODN. By using absorption spectroscopy, it is shown that oligo(dA) conjugated with acridine binds with complementary strand in a 1:1 ratio. The melting temperature showed that the nonmodified (abasic) duplex is destabilized as a result of lacking in base at the abasic site, but the covalently linked acridine ring compensates for the destabilization effect. The fluorescence quantum yield of the acridine ring was enhanced by connection to oligo(dA) and, further, by formation of a double-strand with the complementary ODN. The quantum yield is larger than that of intermolecular intercalation. The excitation spectra of Acr-ODN in the duplex is quite similar to the absorption spectra. The results indicate that the covalently linked acridine ring is selectively intercalated into the adjacent abasic site.
Asunto(s)
Aminoacridinas/química , Colorantes Fluorescentes/química , Oligonucleótidos/química , Acridinas/química , Cromatografía Líquida de Alta Presión/métodos , Calor , Espectroscopía de Resonancia Magnética/métodos , Quinacrina/química , Espectrometría de Fluorescencia , Espectrofotometría Ultravioleta , Temperatura , Treonina/químicaRESUMEN
Oligonucleotides shackled with tetraphenylporphyrin at internucleotide phosphodiester linkage were synthesized and their properties were investigated. The derivatives can hybridize with the complementary oligonucleotide completely. Introduction of porphyrin into the oligonucleotide has little effect on the helix structure and hybridization entirely changes the electronic environment of the porphyrin moiety. Therefore, it is expected that the derivatives locate the photoactive phosphorus(V)porphyrin moiety in close proximity to the target site of DNA.
Asunto(s)
Oligodesoxirribonucleótidos/síntesis química , Secuencia de Bases , Sitios de Unión , Dicroismo Circular , Electroquímica , Estructura Molecular , Desnaturalización de Ácido Nucleico , Hibridación de Ácido Nucleico , Oligodesoxirribonucleótidos/química , Fotoquímica , Porfirinas/químicaRESUMEN
Photocleavages of double-stranded circular DNA and oligonucleotide were investigated by the use of phosphorus(V)tetraphenylporphyrin (P(V)TPP) derivatives. The P(V)TPP derivatives cleaved the DNA and the oligonucleotide under the visible light irradiation, in air and in argon, respectively. It is suggested that the photocleavage reactions include an electron transfer mechanism as well as a singlet oxygen (1O2) one.
Asunto(s)
ADN Viral/química , Glicoles de Etileno/química , Oligorribonucleótidos/química , Porfirinas/química , Bacteriófago phi X 174/genética , Secuencia de Bases , Datos de Secuencia Molecular , Estructura Molecular , Hibridación de Ácido Nucleico , Fotoquímica , Especies Reactivas de OxígenoRESUMEN
Two types of oligonucleotide derivatives which are substituted by P(V) porphyrin at the phosphorus atom of an internucleotidic linkage and at the 5'-terminal internucleotidic linkage via a spacer were synthesized (Fig. 1), and hybridization capabilities of them with complementary oligonucleotides were evaluated. A novel method for a sensing of oligonucleotide by the fluorescence quenching via photo-induced electron transfer between the P(V) porphyrin labeled oligonucleotide and pyrene-labeled one on the oligonucleotide template is reported.
Asunto(s)
Oligonucleótidos/síntesis química , Porfirinas/química , Secuencia de Bases , Electrones , Fluorescencia , Datos de Secuencia MolecularRESUMEN
Oligonucleotide derivatives with a P(V)tetraphenylporphyrin at the internucleotidic phosphodiester linkage were synthesized. Their interactions with the complementary oligonucleotide and pyrene-labeled oligonucleotide were investigated. Fluorescence from the porphyrin moiety was strongly quenched by the addition of the pyrene-labeled oligonucleotide and the template oligonucleotide.
Asunto(s)
Oligodesoxirribonucleótidos/síntesis química , Porfirinas/química , Secuencia de Bases , Datos de Secuencia Molecular , Estructura Molecular , Oligodesoxirribonucleótidos/química , Pirenos/química , Espectrofotometría UltravioletaRESUMEN
2-(N-bis(2-pyrenylethyl)methyl-amino)ethanol (BPAE) was synthesized and its interaction with DNA was examined to explore the efficiency of intramolecular excimer forming probe. As a result the fluorescence of intramolecular excimer of BPAE disappeared with the addition of poly(dA)-poly(dT). This result suggests an unique type of probe with its introduction to oligonucleotide.
Asunto(s)
ADN/análisis , Etanolaminas/síntesis química , Colorantes Fluorescentes/síntesis química , Sondas de Oligonucleótidos/síntesis química , Pirenos/síntesis química , ADN/química , Etanolaminas/química , Colorantes Fluorescentes/química , Estructura Molecular , Sondas de Oligonucleótidos/química , Pirenos/químicaRESUMEN
The synthesis of a self-complementary oligonucleotide possessing an anthraquinonylmethyl substituent at the designated sugar fragment, 5'-CCU(2'AQ)AGCTAGG (1), is described. The anthraquinonylmethyl group was introduced to 2'-hydroxyl moiety of uridine, which was then converted to the protected phosphorobisdiethylamidite derivative. This reagent was used for the solid-phase synthesis of the modified oligonucleotide 1. The UV and CD melting behaviors indicate that the modified oligonucleotide 1 can form a duplex in aqueous buffer solution similar to the unmodified strand 5'-CCTAGCTAGG (7). The observed melting temperatures for the duplexes 1 and 7 were 57.4 and 40.0 degrees C, respectively. The temperature-dependent change in the intensity of the induced CD at around 335 nm reflected directly to the melting behaviors of duplex 1, indicating that the anthraquinone groups intercalate into the base pairs in the duplex. The intercalation-induced stability of the duplex translates into a free energy cost of 5.2 kcal/mol. The present work provides a novel method for enhancing the affinity of oligonucleotides for their complementary sequences.
Asunto(s)
Antraquinonas/síntesis química , Oligonucleótidos/síntesis química , Antraquinonas/química , Secuencia de Bases , Fenómenos Químicos , Química , Dicroismo Circular , Indicadores y Reactivos , Datos de Secuencia Molecular , Estructura Molecular , Oligonucleótidos/química , Compuestos Organofosforados , Espectrofotometría Ultravioleta , TermodinámicaRESUMEN
Oligonucleotides with 1-pyrenylmethyl substituent at the designated sugar residue were synthesized by using 5'-dimethoxytrityl 2'-(1-pyrenylmethyl)uridine 3'-phosphorobisdiethylamidite 1. It was shown that the pyrene-oligonucleotides have enhanced affinity in binding to the complementary polynucleotide sequence. The fluorescence yield and life time of the pyrene-oligonucleotide was drastically enhanced when bound by the complementary polynucleotide.
Asunto(s)
Oligonucleótidos/síntesis química , Pirenos/química , Secuencia de Bases , Carbohidratos/química , Fluorescencia , Datos de Secuencia Molecular , Estructura Molecular , Oligonucleótidos/química , Oligonucleótidos/metabolismoRESUMEN
The oligothymidylate analogs, having several stereo regular phosphoramidate linkages, were synthesized. Melting temperatures(Tm) of complexes of the analogs and poly(dA) were measured by spectroscopic method. The abilities of the analogs to form the complexes with poly(dA) depended on their P-chirality of their modified linkages: one of the chiral isomers formed stable complexes, but another isomer formed less stable complexes.
Asunto(s)
Amidas/química , Oligonucleótidos/química , Ácidos Fosfóricos/química , Estructura Molecular , Poli A/química , TermodinámicaRESUMEN
Silkworm antitrypsin (sw-AT) isolated from larval hemolymph was limitedly digested by Achromobacter lysylendopeptidase, alpha-chymotrypsin, subtilisin BPN', subtilisin Carlsberg, papain, or Pseudomonas elastase. Each proteinase could cleave specific site(s) around the reactive site identified for the reaction of sw-AT and bovine trypsin. Among these proteinases, only subtilisin BPN' was inhibited by sw-AT, although weakly. By the cleavable amino acid sequence in sw-AT, it was suggested that whether or not these proteinases were inhibited by sw-AT did not solely depend on their substrate specificities. The susceptibility to the attack of proteinase should indicate that this region is exposed on the molecular surface. The amino acid sequence in the COOH-terminal region slightly away from the reactive site in sw-AT had homology with that in the corresponding region of the serine proteinase inhibitor (serpin) group.
Asunto(s)
Péptido Hidrolasas/metabolismo , alfa 1-Antitripsina/metabolismo , Secuencia de Aminoácidos , Animales , Bombyx , Electroforesis en Gel de Poliacrilamida , Hemolinfa , Larva , Datos de Secuencia Molecular , Peso Molecular , Fragmentos de Péptidos/aislamiento & purificación , Inhibidores de Proteasas , Homología de Secuencia de Ácido NucleicoRESUMEN
Silkworm antitrypsin (sw-AT), which was thought to belong to serpin family, changed its behavior against denaturation after chymotryptic cleavage of a single peptide bond (Tyr-Val) two amino acids away from the reactive site for trypsin (Lys-Val). This chymotrypsin-modified sw-AT became resistant to denaturation by heat, sodium dodecyl sulfate, or guanidine hydrochloride, and this characteristic was evident in its circular dichroism spectrum. The modified sw-AT was also indigestible by S. aureus V8 protease. These facts should indicate a structural change from a stressed, unstable state to a stable one accompanying the cleavage of the single peptide bond in sw-AT. The stabilizing factor was in part attributed to the interaction of a COOH-terminal fragment (5 kDa) and an NH2-terminal one (36 kDa) in modified sw-AT.
Asunto(s)
Quimotripsina/metabolismo , Desnaturalización Proteica , Serina Endopeptidasas/metabolismo , alfa 1-Antitripsina/metabolismo , Animales , Bombyx , Dicroismo Circular , Guanidina , Guanidinas/farmacología , Hemolinfa , Cinética , Larva , Conformación ProteicaRESUMEN
Utilities of deoxyribonucleoside 3'-O-phosphorbisdiethylamidites in the synthesis of oligodeoxyribonucleotides and their analogues are described.
Asunto(s)
Oligodesoxirribonucleótidos/síntesis química , Desoxirribonucleósidos , Indicadores y Reactivos , Compuestos OrganofosforadosRESUMEN
The oligothymidilate analogues, having stereoregular and alternative phosphormorpholidate/phosphodiester backbone, were synthesized from the diastereochemically pure dimer blocks by phosphorbisamidite method. The phosphormorpholidate linkage of the oligothymidilate analogues were resistant to snake venom phosphodiesterase, and no cleavage of the phosphodiester linkage of the analogues were slowly cleaved by the nuclease was slow. The abilities of isomers to form the complexes with poly(dA) greatly depended on their structures.
Asunto(s)
Oligodesoxirribonucleótidos/síntesis química , Amidas , Oligodesoxirribonucleótidos/metabolismo , Fosfodiesterasa I , Ácidos Fosfóricos , Hidrolasas Diéster Fosfóricas , EstereoisomerismoRESUMEN
mediates to synthesize the oligodeoxynucleotides have been synthesize otected nucleoside using morpholinophosphorditetrazolide. From these sequence-defined oligodeoxynucleotides were also synthesized. The gen is composed of following steps; a) reaction of 5'-O-protected nucleo orpholinophosphorditetrazolide (phosphitilation), b) reaction of the nucleoside phosphoramidite with the second nucleoside (condensation), ueous oxidation with t-BuOOH (oxidation). RE 1/hlp F2/cmt F3/ext F4/can F5/nxt F6/ins F7/up F8/dwn F9/fin