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1.
Eur Rev Med Pharmacol Sci ; 28(11): 3781-3786, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38884513

RESUMO

OBJECTIVE: Tinnitus Retraining Therapy (TRT) is a rehabilitation approach for tinnitus that is currently considered an effective treatment with an elevated response rate. TRT is usually delivered through sound generators; however, they are often difficult to find and expensive. Recently, mobile apps have been proposed for TRT. This study aims to verify the effectiveness of TRT performed using mobile apps in reducing the adverse effects of tinnitus on the quality of life. PATIENTS AND METHODS: A total of 80 patients affected by tinnitus in category 0 (mild tinnitus) and category 1 (moderate tinnitus), according to the Jastreboff classification, were included in the study. Patients of both classes were subsequently differentiated into two homogeneous groups; the first (Group A) was treated with a traditional sound generator, and the second (Group B) using a mobile app. The Tinnitus Handicap Inventory - the Italian version of the questionnaire - was used to investigate the impact of tinnitus on the quality of life in enrolled patients and evaluate their response to TRT. RESULTS: A significant improvement was found in THI scores in category 0 patients for both sound generator and mobile app groups; no difference was found between the two-treatment delivery technology (-1.186, p=0.783); conversely, tinnitus improvements in category 1 patients were only reported for subjects treated using a sound generator (-14.529, p<0.001), while no significant improvement was found in patients treated using the mobile app. CONCLUSIONS: This study confirms the value of TRT, which in patients with mild tinnitus (category 0), can also be delivered through mobile apps with results comparable to traditional sound generators. Further studies are necessary to confirm the effects of the different tinnitus treatments available and improve the knowledge on this topic.


Assuntos
Aplicativos Móveis , Qualidade de Vida , Zumbido , Zumbido/terapia , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Som , Adulto , Inquéritos e Questionários , Idoso , Resultado do Tratamento
2.
Eur Rev Med Pharmacol Sci ; 24(15): 7946-7952, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32767320

RESUMO

OBJECTIVE: The awareness of audio-vestibular side effects of drugs, such as hearing loss, tinnitus, dizziness and vertigo, has widely increased in the recent years. The present guide represents an update of the previous documents published by the authors in 2005 and 2011 on drug-induced ototoxicity and vestibulotoxicity. MATERIALS AND METHODS: The authors performed a comprehensive analysis of audio-vestibular side effects of commercially available drugs based on the British National Formulary, a pharmaceutical reference book that contains a wide range of useful information and advice on prescription and pharmacology. RESULTS: Commercially available drugs and their active principles have been classified based on their audio-vestibular side effects, as reported by the pharmaceutical companies and/or health agencies. Drugs have been categorized based on the field of application, the therapeutic indication and the pharmacological properties. CONCLUSIONS: General practitioners, otolaryngology, neurology and audiology specialists should be aware of possible audio-vestibular side effects of drugs, such as hearing loss, tinnitus, dizziness and vertigo. The present guide represents a practical tool to rapidly identify potential audio-vestibular side effects of drugs as reported by the pharmaceutical companies and/or health agencies.


Assuntos
Tontura , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Perda Auditiva , Preparações Farmacêuticas/administração & dosagem , Zumbido , Vertigem , Humanos
3.
Chromosome Res ; 21(2): 101-6, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23580138

RESUMO

The first centromeric protein identified in any species was CENP-A, a divergent member of the histone H3 family that was recognised by autoantibodies from patients with scleroderma-spectrum disease. It has recently been suggested to rename this protein CenH3. Here, we argue that the original name should be maintained both because it is the basis of a long established nomenclature for centromere proteins and because it avoids confusion due to the presence of canonical histone H3 at centromeres.


Assuntos
Autoantígenos/genética , Proteínas Cromossômicas não Histona/genética , Histonas/genética , Autoantígenos/metabolismo , Centrômero , Proteína Centromérica A , Proteínas Cromossômicas não Histona/metabolismo , Histonas/metabolismo , Humanos , Cinetocoros , Escleroderma Sistêmico/genética , Terminologia como Assunto
4.
Cell Death Differ ; 20(6): 834-44, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23519077

RESUMO

The chromosomal passenger complex (CPC) acts as a key regulator of mitosis, preventing asymmetric segregation of chromosomal material into daughter cells. The CPC is composed of three non-enzymatic components termed Survivin, the inner centromere protein (INCENP) and Borealin, and an enzymatic component, Aurora B kinase. Survivin is necessary for the appropriate separation of sister chromatids during mitosis and is involved in liver regeneration, but its role in regenerative processes is incompletely elucidated. Whether Survivin, which is classified as an inhibitor of apoptosis protein (IAP) based on domain composition, also has a role in apoptosis is controversial. The present study examined the in vivo effects of Survivin ablation in the liver and during liver regeneration after 70% hepatectomy in a hepatocyte-specific knockout mouse model. The absence of Survivin caused a reduction in the number of hepatocytes in the liver, together with an increase in cell volume, macronucleation and polyploidy, but no changes in apoptosis. During liver regeneration, mitosis of hepatocytes was associated with mislocalization of the members of the CPC, which were no longer detectable at the centromere despite an unchanged protein amount. Furthermore, the loss of survivin in regenerating hepatocytes was associated with reduced levels of phosphorylated Histone H3 at serine 28 and abolished phosphorylation of CENP-A and Hec1 at serine 55, which is a consequence of decreased Aurora B kinase activity. These data indicate that Survivin expression determines hepatocyte number during liver development and liver regeneration. Lack of Survivin causes mislocalization of the CPC members in combination with reduced Aurora B activity, leading to impaired phosphorylation of its centromeric target proteins and inappropriate cytokinesis.


Assuntos
Proteínas Inibidoras de Apoptose/deficiência , Regeneração Hepática/fisiologia , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Repressoras/deficiência , Animais , Apoptose/fisiologia , Aurora Quinase B , Aurora Quinases , Processos de Crescimento Celular/fisiologia , Proteínas Inibidoras de Apoptose/genética , Proteínas Inibidoras de Apoptose/metabolismo , Camundongos , Camundongos Transgênicos , Fosforilação , Proteínas Serina-Treonina Quinases/genética , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Survivina
6.
Plant Biol (Stuttg) ; 11(6): 821-8, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19796359

RESUMO

Many factors have contributed to the richness of narrow endemics in the Mediterranean, including long-lasting human impact on pristine landscapes. The abandonment of traditional land-use practices is causing forest recovery throughout the Mediterranean mountains, by increasing reduction and fragmentation of open habitats. We investigated the population genetic structure and habitat dynamics of Plantago brutia Ten., a narrow endemic in mountain pastures of S Italy. Some plants were cultivated in the botanical garden to explore the species' breeding system. Genetic diversity was evaluated based on inter-simple sequence repeat (ISSR) polymorphisms in 150 individuals from most of known stands. Recent dynamics in the species habitat were checked over a 14-year period. Flower phenology, stigma receptivity and experimental pollinations revealed protogyny and self-incompatibility. With the exception of very small and isolated populations, high genetic diversity was found at the species and population level. amova revealed weak differentiation among populations, and the Mantel test suggested absence of isolation-by-distance. Multivariate analysis of population and genetic data distinguished the populations based on genetic richness, size and isolation. Landscape analyses confirmed recent reduction and isolation of potentially suitable habitats. Low selfing, recent isolation and probable seed exchange may have preserved P. brutia populations from higher loss of genetic diversity. Nonetheless, data related to very small populations suggest that this species may suffer further fragmentation and isolation. To preserve most of the species' genetic richness, future management efforts should consider the large and isolated populations recognised in our analyses.


Assuntos
Ecossistema , Plantago/genética , Biodiversidade , Conservação dos Recursos Naturais , Flores/genética , Flores/crescimento & desenvolvimento , Região do Mediterrâneo , Repetições Minissatélites , Filogenia , Plantago/crescimento & desenvolvimento , Polinização/fisiologia , Polimorfismo Genético , Especificidade da Espécie
7.
Plant Biol (Stuttg) ; 11(3): 434-41, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19470114

RESUMO

Plant species diversification entails the action of reproductive barriers, which are severely challenged when related species grow in contact and form hybrid progeny. Orchis italica and O. anthropophora are two related orchid species that produce a known hybrid form, O. xbivonae. Here, we analysed a hybrid zone of these two orchids using molecular analysis and experimental crosses. As molecular tools, we employed both real-time PCR and PCR amplification of nuclear markers to evaluate the occurrence of backcross recombination. With these approaches, we demonstrated that all examined hybrids belong to the F(1) generation. Chloroplast DNA analysis showed that O. anthropophora was the maternal species of most of hybrid specimens and that cytoplasmic introgression was lacking in both parental species. Pollination experiments showed that the two orchid species were strictly out-crossing, although self-compatible, and have comparable levels of reproductive fitness in all crossing treatments. Conversely, hybrids demonstrated low reproductive success in all intra- and back-crossing treatments. The absence of any backcross generations and plastid introgression suggest that O. xbivonae does not represent a bridge to gene flow between O. italica and O. anthropophora. Indeed, the low hybrid fitness testifies to the effectiveness of late post-zygotic barriers occurring between the parental species.


Assuntos
DNA de Cloroplastos , Fluxo Gênico , Hibridização Genética , Orchidaceae/genética , Frutas , Polinização , Reação em Cadeia da Polimerase , Reprodução , Reação em Cadeia da Polimerase Via Transcriptase Reversa
8.
Cell Death Differ ; 16(2): 321-30, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18974773

RESUMO

Reversine is a synthetic molecule capable of inducing dedifferentiation of C2C12, a murine myoblast cell line, into multipotent progenitor cells, which can be redirected to differentiate in nonmuscle cell types under appropriate conditions. Reversine is also a potent inhibitor of Aurora B, a protein kinase required for mitotic chromosome segregation, spindle checkpoint function, cytokinesis and histone H3 phosphorylation, raising the possibility that the dedifferentiation capability of reversine is mediated through the inhibition of Aurora B. Indeed, here we show that several other well-characterized Aurora B inhibitors are capable of dedifferentiating C2C12 myoblasts. Significantly, expressing drug-resistant Aurora B mutants, which are insensitive to reversine block the dedifferentiation process, indicating that Aurora B kinase activity is required to maintain the differentiated state. We show that the inhibition of the spindle checkpoint or cytokinesis per se is not sufficient for dedifferentiation. Rather, our data support a model whereby changes in histone H3 phosphorylation result in chromatin remodeling, which in turn restores the multipotent state.


Assuntos
Mioblastos/citologia , Mioblastos/enzimologia , Proteínas Serina-Treonina Quinases/metabolismo , Animais , Aurora Quinase B , Aurora Quinases , Diferenciação Celular , Linhagem Celular , Cromatina/metabolismo , Citocinese/efeitos dos fármacos , Histonas/metabolismo , Humanos , Camundongos , Modelos Biológicos , Morfolinas/farmacologia , Proteínas Mutantes/metabolismo , Mioblastos/efeitos dos fármacos , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Purinas/farmacologia
9.
Mol Phylogenet Evol ; 47(3): 986-91, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18434211

RESUMO

A molecular phylogenetic analysis was performed on 14 species of the Mediterranean unrewarding orchid genus Serapias using sequences of four noncoding regions of chloroplast DNA. This study has led to a new interpretation of the evolutionary relationships in this genus. The well-defined phylogenetic tree supports a division of taxa into two main clades, each including two minor groups. The molecular relationships found in this study differ from those defined by traditional systematic morphological assessments. By comparing the variation in sequence to variations in floral traits, we propose that the split in the two main lineages reflects an early differentiation of flower size, perhaps due to the shift from allo- to self-pollination. Conversely, the relationships within each minor group do not reflect floral size variation; therefore, we presume that this diversification resulted from genetic drift, local selection forces, and multiple, independent transitions towards self-pollination and polyploidy.


Assuntos
DNA de Cloroplastos/genética , DNA Intergênico/genética , Genoma de Planta/genética , Orchidaceae/genética , Filogenia , Alinhamento de Sequência , Análise de Sequência de DNA
10.
Adv Otorhinolaryngol ; 65: 133-136, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17245034

RESUMO

The aim of the study was to investigate changes in middle ear dynamic characteristics caused by both otosclerosis and stapes surgery (platinotomy, prosthesis positioning, ossicular chain maneuver) and to evaluate distortion product otoacoustic emissions (DPOAEs) before and following surgery. The study included 15 patients (12 women, 3 men; mean age 51 years; range 32-69 years) with advanced otosclerosis. All the patients were evaluated with the use of pure-tone audiograms (preoperatively, 5 and 30 days after surgery), stapedial reflexes (preoperatively), and DPOAE recordings (preoperatively, at the end of surgery, and 5 and 30 days after surgery). Changes in the hearing thresholds and in the DPOAE amplitudes were compared. Preoperative tests showed conductive hearing loss, with a mean air-bone gap of 36.6 dB HL ranging from 0.25 to 1 kHz, and no stapedial reflexes were detected. DPOAEs were not measurable preoperatively, and they were detected only in 2 patients at the end of surgery, with low amplitudes in a narrow frequency range. No significant changes occurred in DPOAEs 5 days postoperatively. A month after surgery, improvement in conductive hearing loss was observed; the mean air-bone gap from 0.25 to 1 kHz was 12.9 dB HL, whereas the higher frequencies were still affected by the disease. DPOAEs increased in amplitude in 4 patients, but this was not significant. It remains unclear why DPOAEs are not detected despite a subjective hearing improvement and a sufficiently closed air-bone gap at least in middle and low frequencies. The results of our study show that DPOAEs cannot replace behavioral threshold tests; they may only be included in a battery of tests for a complete clinical follow-up for efficiency monitoring after stapes surgery.


Assuntos
Perda Auditiva Condutiva/cirurgia , Monitorização Intraoperatória , Emissões Otoacústicas Espontâneas/fisiologia , Otosclerose/cirurgia , Adulto , Idoso , Audiometria de Tons Puros , Limiar Auditivo/fisiologia , Condução Óssea/fisiologia , Feminino , Seguimentos , Perda Auditiva Condutiva/diagnóstico , Perda Auditiva Condutiva/fisiopatologia , Humanos , Complicações Intraoperatórias/diagnóstico , Complicações Intraoperatórias/fisiopatologia , Complicações Intraoperatórias/cirurgia , Masculino , Pessoa de Meia-Idade , Prótese Ossicular , Otosclerose/diagnóstico , Otosclerose/fisiopatologia , Reflexo Acústico/fisiologia , Sensibilidade e Especificidade , Cirurgia do Estribo , Resultado do Tratamento
11.
J Hered ; 96(1): 15-23, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15618311

RESUMO

Flowers of the Mediterranean orchid genus Serapias L. form small, dark tubes that vary among taxa in diameter and depth. Visiting insects use the floral tube as shelter and act as pollinators if they touch the sticky viscidium at the rear of the tube and remove the pollinarium. It has been assumed that floral tube size and shape limit access to the flowers and thus may act as a barrier to gene flow between different Serapias species. Here we investigated floral characters and nuclear microsatellite markers in populations belonging to three morphologically similar Serapias species to test whether these species show evidence for floral or reproductive isolation. We found strong overlap of floral traits between two species, suggesting that floral isolation is nonexistent between them. Microsatellite markers applied to the same populations were highly polymorphic and revealed clear genetic differentiation among all three species. These results suggest that reproductive isolation exists, despite the lack of floral isolation between two of the species. In contrast to morphological characters, diagnostic microsatellite alleles were found for all Serapias species. The microsatellite markers could thus provide a useful tool to identify Serapias species and further investigate evolutionary relationships in this fascinating orchid lineage.


Assuntos
Flores/genética , Orchidaceae/genética , Alelos , Flores/anatomia & histologia , Frequência do Gene , Geografia , Grécia , Itália , Repetições de Microssatélites , Orchidaceae/anatomia & histologia , Orchidaceae/fisiologia
12.
Mol Ecol ; 12(10): 2783-92, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12969480

RESUMO

The phylogeographical history of the rare marsh orchid Anacamptis palustris (Orchidaceae) was reconstructed using highly polymorphic chloroplast minisatellite and microsatellite loci. Allelic variation at chloroplast microsatellite loci was due to length variation in poly(A/T) repeats and was informative on a regional scale, but was not sufficient to unravel relationships among populations on a local geographical scale. The minisatellite locus, however, was found to be highly variable. Nine distinct repeat types were found and variation in repeat number occurred in five repeat types. The distribution of chloroplast haplotypes, combining microsatellite and minisatellite repeat type variation, provided a clear phylogeographical picture on a large geographical scale, whereas length variation in one highly polymorphic minisatellite repeat type provided fine-scale phylogeographical information. Mediterranean populations could be divided into four main lineages, a western European lineage, a northern and central Italian lineage, a well-isolated southern Italian (Apulian) lineage, and an eastern European lineage. Variation at the most variable minisatellite repeat type N revealed 19 alleles and allowed the study of seed-mediated gene flow and an estimation of the ratio of pollen to seed flow among neighbouring populations.


Assuntos
Variação Genética , Genética Populacional , Geografia , Orchidaceae/genética , Filogenia , Sequência de Bases , Primers do DNA , DNA de Cloroplastos/genética , Europa (Continente) , Frequência do Gene , Repetições de Microssatélites/genética , Repetições Minissatélites/genética , Dados de Sequência Molecular , Orchidaceae/fisiologia , Alinhamento de Sequência
13.
Clin Biochem ; 36(1): 41-9, 2003 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12554059

RESUMO

It has been shown that the Hepatitis C virus nonstructural NS3 protein possesses at least two enzymatic domains: a serine-protease domain and an adenosine triphosphatase (ATPase)/helicase domain. In this report, a truncated fragment of NS3 (26 kDa), representing main epitopes from the (ATPase)/helicase domain, has been expressed in Escherichia coli. The recombinant protein was purified by Ion Metal Affinity Chromatography (IMAC) with more than 90% purity. The recognition of B-cell linear epitopes in the NS3 protein was evaluated by immunoblot. The recombinant NS3 protein was reduced and carboxymethylated, and the recognition of either conformational and/or linear B-cell determinants was evaluated by ELISA. The inclusion of the recombinant NS3 protein in a third-generation diagnostic system UltraMicroELISA (UMELISA) allowed an increase in the sensitivity, due to the detection of a new variety of false-negative sera in blood donor test samples.


Assuntos
Adenosina Trifosfatases/química , DNA Helicases/química , Proteínas não Estruturais Virais/química , Proteínas não Estruturais Virais/genética , Cromatografia de Afinidade , Clonagem Molecular , Eletroforese em Gel de Poliacrilamida , Ensaio de Imunoadsorção Enzimática , Epitopos , Escherichia coli/metabolismo , Fermentação , Immunoblotting , Modelos Genéticos , Plasmídeos/metabolismo , Estrutura Terciária de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Temperatura
14.
EMBO J ; 20(23): 6648-59, 2001 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-11726501

RESUMO

The kinetochore checkpoint pathway, involving the Mad1, Mad2, Mad3, Bub1, Bub3 and Mps1 proteins, prevents anaphase entry and mitotic exit by inhibiting the anaphase promoting complex activator Cdc20 in response to monopolar attachment of sister kinetochores to spindle fibres. We show here that Cdc20, which had previously been shown to interact physically with Mad2 and Mad3, associates also with Bub3 and association is up-regulated upon checkpoint activation. Moreover, co-fractionation experiments suggest that Mad2, Mad3 and Bub3 may be concomitantly present in protein complexes with Cdc20. Formation of the Bub3-Cdc20 complex requires all kinetochore checkpoint proteins but, surprisingly, not intact kinetochores. Conversely, point mutations altering the conserved WD40 motifs of Bub3, which might be involved in the formation of a beta-propeller fold devoted to protein-protein interactions, disrupt its association with Mad2, Mad3 and Cdc20, as well as proper checkpoint response. We suggest that Bub3 could serve as a platform for interactions between kinetochore checkpoint proteins, and its association with Mad2, Mad3 and Cdc20 might be instrumental for checkpoint activation.


Assuntos
Proteínas de Ligação ao Cálcio/metabolismo , Proteínas de Transporte , Proteínas de Ciclo Celular/metabolismo , Proteínas Fúngicas/metabolismo , Cinetocoros/metabolismo , Proteínas/química , Proteínas/metabolismo , Proteínas de Saccharomyces cerevisiae , Motivos de Aminoácidos , Sequência de Aminoácidos , Western Blotting , Proteínas de Ligação ao Cálcio/química , Proteínas Cdc20 , Proteínas de Ciclo Celular/química , Cromatografia em Gel , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Proteínas Mad2 , Dados de Sequência Molecular , Proteínas Nucleares , Plasmídeos/metabolismo , Mutação Puntual , Testes de Precipitina , Ligação Proteica , Dobramento de Proteína , Sequências Repetitivas de Aminoácidos , Homologia de Sequência de Aminoácidos , Fatores de Tempo
15.
EMBO J ; 20(22): 6371-82, 2001 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-11707408

RESUMO

Mad2 is a key component of the spindle checkpoint, a device that controls the fidelity of chromosome segregation in mitosis. The ability of Mad2 to form oligomers in vitro has been correlated with its ability to block the cell cycle upon injection into Xenopus embryos. Here we show that Mad2 forms incompatible complexes with Mad1 and Cdc20, neither of which requires Mad2 oligomerization. A monomeric point mutant of Mad2 can sustain a cell cycle arrest of comparable strength to that of the wild-type protein. We show that the interaction of Mad2 with Mad1 is crucial for the localization of Mad2 to kinetochores, where Mad2 interacts with Cdc20. We propose a model that features the kinetochore as a 'folding factory' for the formation of a Mad2-Cdc20 complex endowed with inhibitory activity on the anaphase promoting complex.


Assuntos
Proteínas de Ligação ao Cálcio/metabolismo , Proteínas de Transporte , Proteínas de Ciclo Celular/metabolismo , Proteínas Fúngicas/metabolismo , Fosfoproteínas/metabolismo , Proteínas Repressoras/metabolismo , Proteínas de Saccharomyces cerevisiae , Anáfase , Animais , Anticorpos Monoclonais/metabolismo , Sítios de Ligação , Proteínas Cdc20 , Ciclo Celular , Cromatografia em Gel , DNA Complementar/metabolismo , Eletroforese em Gel de Poliacrilamida , Escherichia coli/metabolismo , Células HeLa , Humanos , Cinetocoros/metabolismo , Proteínas Mad2 , Camundongos , Microscopia de Fluorescência , Mitose , Modelos Biológicos , Mutagênese Sítio-Dirigida , Proteínas Nucleares , Peptídeos/química , Plasmídeos/metabolismo , Mutação Puntual , Reação em Cadeia da Polimerase , Testes de Precipitina , Ligação Proteica , Proteínas Recombinantes/metabolismo , Cloreto de Sódio/farmacologia , Transfecção , Ureia/farmacologia
16.
Mol Cell ; 8(3): 657-69, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11583627

RESUMO

CDK5 plays an indispensable role in the central nervous system, and its deregulation is involved in neurodegeneration. We report the crystal structure of a complex between CDK5 and p25, a fragment of the p35 activator. Despite its partial structural similarity with the cyclins, p25 displays an unprecedented mechanism for the regulation of a cyclin-dependent kinase. p25 tethers the unphosphorylated T loop of CDK5 in the active conformation. Residue Ser159, equivalent to Thr160 on CDK2, contributes to the specificity of the CDK5-p35 interaction. Its substitution with threonine prevents p35 binding, while the presence of alanine affects neither binding nor kinase activity. Finally, we provide evidence that the CDK5-p25 complex employs a distinct mechanism from the phospho-CDK2-cyclin A complex to establish substrate specificity.


Assuntos
Quinases Ciclina-Dependentes/química , Proteínas do Tecido Nervoso/química , Sequência de Aminoácidos , Animais , Sítios de Ligação , Células COS , Cristalografia por Raios X , Quinase 5 Dependente de Ciclina , Quinases Ciclina-Dependentes/metabolismo , Humanos , Immunoblotting , Modelos Moleculares , Dados de Sequência Molecular , Proteínas do Tecido Nervoso/metabolismo , Peptídeos/química , Peptídeos/metabolismo , Fosforilação , Ligação Proteica , Conformação Proteica , Estrutura Terciária de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência
17.
Biochem Biophys Res Commun ; 287(1): 122-5, 2001 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-11549263

RESUMO

Little is known about the mechanism of hepatitis C virion assembly. So the capacity of the entire Hepatitis C virus core protein (HCcAg) produced in Pichia pastoris to form particles either in its native soluble state or after detergent treatment of HCcAg associated to cell debris were studied. Size exclusion chromatography suggested that HCcAg assembled into high molecular weight structures. HCcAg was also specifically recognized by a serum from a chronic HCV carrier patient. This antigen migrated with buoyant density values similar to those obtained for native nucleocapsid particles from infected patients when analyzed using sucrose density gradient centrifugation. The analysis by electron microscopy of purified HCcAg showed aggregates resembling virus-like particles (VLPs) with an average diameter of 30 nm. These results indicated that the HCcAg obtained from P. pastoris assembled into VLPs resembling HCV nucleocapsid particles in a mature stage. Such HCcAg aggregates characterized here could be a valuable tool to elucidate the mechanisms of HCV nucleocapsid assembly.


Assuntos
Hepacivirus/química , Pichia/virologia , Proteínas do Core Viral/química , Vírion/química , Immunoblotting , Peso Molecular , Renaturação Proteica , Proteínas do Core Viral/metabolismo
18.
Curr Genet ; 39(5-6): 394-8, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11525416

RESUMO

We describe the occurrence of a tandem repeat in the chloroplast genome of the marsh orchid, Orchis palustris. The repeat unit is an AT-rich, 16-bp sequence located in the chloroplast tRNALEU intron. Southern blot analysis confirmed that the O. palustris tRNALEU intron including the minisatellite locus has not been transferred to the nucleus, but is indeed located on the chloroplast genome. The 16-bp repeat unit was found to be present in all O. palustris accessions studied, as well as in the closely related O. laxiflora. Variation in repeat numbers among individuals was found in O. palustris from central and northern Italy; and this was consistently associated with a 13-bp sequence motif preceding the repeat. This motif was absent from O. palustris from southern Italy, Greece, and from O. laxiflora. In these accessions, no variation in repeat numbers was found. Our results suggest that the O. palustris chloroplast minisatellite locus evolved relatively recently, presumably in central Italy, and may represent a valuable marker for population genetic studies.


Assuntos
Cloroplastos/genética , DNA de Plantas/genética , Genoma de Planta , Magnoliopsida/genética , Repetições Minissatélites/genética , Composição de Bases , Sequência de Bases , DNA de Plantas/química , Variação Genética , Íntrons , Dados de Sequência Molecular , RNA de Plantas/química , RNA de Plantas/genética , RNA de Transferência de Leucina/genética , Sequências Repetitivas de Ácido Nucleico , Alinhamento de Sequência , Homologia de Sequência do Ácido Nucleico
19.
Biotechnol Appl Biochem ; 34(1): 63-9, 2001 08.
Artigo em Inglês | MEDLINE | ID: mdl-11483156

RESUMO

The reconstitution of recombinant bacterial outer membrane proteins (OMPs) into their native conformations after purification has been the major problem in their use as effective vaccines. Liposomes have been shown to be an attractive approach, providing a native-like environment for these antigens. The meningococcal recombinant Opc (rOpc) protein, produced as inclusion bodies in Escherichia coli, was incorporated into phospholipid vesicles consisting of dipalmitoyl phosphatidylcholine and cholesterol. The incorporation of rOpc into the lipid bilayer was demonstrated, and the reconstitution of some native epitopes was tested using a set of monoclonal antibodies. Subcutaneous immunization of Balb/c mice with rOpc-containing vesicles resulted in the generation of a high level of specific antibodies. The elicited antibodies reacted with the native meningococcal protein and showed opsonic activity.


Assuntos
Proteínas da Membrana Bacteriana Externa/química , Neisseria meningitidis/química , Proteínas Recombinantes/química , 1,2-Dipalmitoilfosfatidilcolina/química , Animais , Anticorpos Monoclonais/metabolismo , Proteínas da Membrana Bacteriana Externa/metabolismo , Western Blotting , Colesterol/química , Relação Dose-Resposta a Droga , Ensaio de Imunoadsorção Enzimática , Escherichia coli/metabolismo , Immunoblotting , Bicamadas Lipídicas/química , Lipossomos/química , Camundongos , Camundongos Endogâmicos BALB C , Proteínas Recombinantes/metabolismo
20.
Vaccine ; 19(27): 3692-9, 2001 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-11395203

RESUMO

The nasal mucosa may provide a simple, non-invasive route to deliver DNA encoding genes that stimulate a specific immune response. Based on this, a new approach using pCMVbeta-gal plasmid DNA complexed to the Opc meningococcal outer membrane protein was assayed for. Optimal conditions of interaction were established between recombinant Opc protein and pCMVbeta-gal plasmid DNA. Complexes were fully characterized by electrophoresis analysis, DNAse resistance assay and transmission electron microscopy. DNA-protein complexes were also evaluated in in vitro transfection experiments. After the characterisation of complexes, Balb/c mice were intranasal (i.n.) and intramuscularly (i.m.) immunized. The humoral immune response against beta-galactosidase was measured by ELISA. The proliferative response in the spleen lymph nodes was also measured. Complexes administered by i.n. route induced both systemic and mucosal antibody responses. This behavior was not observed with the naked DNA. Finally, a lymphoproliferative response specific to beta-galactosidase induced by DNA-protein complexes was also detected.


Assuntos
Antígenos de Bactérias/imunologia , Proteínas da Membrana Bacteriana Externa/imunologia , Plasmídeos/imunologia , Vacinas de DNA/administração & dosagem , Vacinas de DNA/imunologia , Administração Intranasal , Animais , Antígenos de Bactérias/administração & dosagem , Antígenos de Bactérias/genética , Proteínas da Membrana Bacteriana Externa/administração & dosagem , Proteínas da Membrana Bacteriana Externa/genética , Células COS , Linhagem Celular , Esquemas de Imunização , Camundongos , Camundongos Endogâmicos BALB C , Plasmídeos/administração & dosagem , Plasmídeos/metabolismo , Plasmídeos/ultraestrutura , Transfecção
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