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1.
Bioanalysis ; 8(4): 285-95, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26847798

RESUMO

AIMS: Heparan sulfate (HS) accumulates in the central nervous system in mucopolysaccharidosis III type A (MPS IIIA). A validated LC-MS/MS assay was developed to measure HS in human cerebrospinal fluid (CSF). METHODS & RESULTS: HS was extracted and digested and the resultant disaccharides were derivatized with a novel label, 4-butylaniline, enabling isoform separation and isotope-tagged analog introduction as an internal standard for LC-MS/MS. The assay has a LLOQ for disaccharides of 0.1 µM, ±20% accuracy and ≤20% precision. CSF samples from patients with MPS IIIA showed elevated HS levels (mean 4.9 µM) compared with negative controls (0.37 µM). CONCLUSION: This assay detected elevated HS levels in the CSF of patients with MPS IIIA and provides a method to assess experimental therapies.


Assuntos
Cromatografia Líquida/métodos , Heparitina Sulfato/líquido cefalorraquidiano , Mucopolissacaridose III/líquido cefalorraquidiano , Espectrometria de Massas em Tandem/métodos , Adolescente , Criança , Pré-Escolar , Cromatografia Líquida/normas , Heparitina Sulfato/isolamento & purificação , Humanos , Lactente , Limite de Detecção , Valores de Referência
3.
Vector Borne Zoonotic Dis ; 7(3): 426-36, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17767409

RESUMO

Ixodes persulcatus Schultze ticks are traditionally associated with transmission of Lyme disease, babesiosis, and tick-borne encephalitis. Here we compared the prevalence of infection with Borrelia burgdorferi, and rickettsial and ehrlichial agents in I. persulcatus ticks collected in different locations of the North Western administrative region of Russia. Altogether, 27.7% of ticks were infected with at least one organism, while the DNA of two or more bacteria was found in 11.8% of ticks tested. The highest average prevalence of Anaplasmataceae (20.8%) was detected in ticks from Arkhangel'sk province, while the prevalence in ticks from Novgorod province and St. Petersburg, respectively, was 7.3% and 12.2%. Only Ehrlichia muris DNA was identified by DNA sequencing. In comparison, the prevalence of B. burdorferi DNA was 16.6%, 5.8%, and 24.5% in the respective locations. The 382-bp amplicon of gltA from Candidatus Rickettsia tarasevichiae was detected in 2.75% and 1.6%, respectively, of ticks from Arkhangel'sk and Novgorod provinces, extending further west and north the area where this rickettsia is known to be present. DNA of the rickettsia-like endosymbiont Montezuma was primarily associated with female ticks, 8-28% of which were infected. Since I. persulcatus is so commonly infected with multiple agents that may cause human diseases, exposure to these ticks poses significant risk to human health in this region.


Assuntos
Vetores Artrópodes/microbiologia , Bactérias/isolamento & purificação , Ixodes/microbiologia , Anaplasmataceae/genética , Anaplasmataceae/isolamento & purificação , Animais , Bactérias/genética , Benzotiazóis , Borrelia/genética , Borrelia/isolamento & purificação , Diaminas , Ehrlichia/genética , Ehrlichia/isolamento & purificação , Feminino , Masculino , Dados de Sequência Molecular , Compostos Orgânicos/análise , Reação em Cadeia da Polimerase , Prevalência , Quinolinas , Rickettsia/genética , Rickettsia/isolamento & purificação , Federação Russa
4.
J Prosthodont ; 16(6): 421-30, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17683475

RESUMO

PURPOSE: The purpose of this project was to compare alveolar bone repair by allogeneic mesenchymal stem cells using bioglass or synthetic hydroxyapatite (HA)/tricalcium phosphate (TCP) granular scaffolds delivered in a thermoplastic polymeric carrier. MATERIALS AND METHODS: Canine mesenchymal stem cells were obtained from iliac crest bone marrow of beagle dogs and expanded without differentiation. Cells were resuspended at a final concentration of 5 x 10(6) cells/ml in a thermoplastic polymeric carrier (30% w/v Pluronic F-127) and mixed with an equal volume of synthetic HA/TCP or bioglass scaffold and placed into surgically created 5 mm cylindrical defects in the edentulous premolar region of beagle dogs. After 4 weeks or 7 weeks, tissue healing was evaluated by standard histomorphometric methods (Bioquant Nova, Bioquant Image Analysis Corporation, Nashville, TN) by measurement of bone formation within five random sites from each biopsy. RESULTS: After 4 weeks, sites treated with or without mesenchymal stem cells contained 58.25 +/-18.43% or 43.35 +/- 17.68% bone area (p= 0.049), respectively. After 7 weeks, sites treated with or without mesenchymal stem cells contained 62.73 +/- 19.10% or 60.39 +/- 21.32% bone area. Bone formation occurred without inflammation in defects treated using Pluronic F-127 carrier with and without mesenchymal stem cells. There was no difference in percent bone area when bioglass or HA/TCP scaffolds were compared at either time point. CONCLUSIONS: The thermoplastic polymeric carrier did not limit alveolar bone repair in the canine mandible. The combination of a thermoplastic, viscous carrier with a granular scaffold allowed for the delivery of allogeneic mesenchymal stem cells in a clinically manageable form that enhanced bone formation at early stages of alveolar repair.


Assuntos
Mandíbula/cirurgia , Transplante de Células-Tronco Mesenquimais/métodos , Poloxâmero/uso terapêutico , Tensoativos/uso terapêutico , Engenharia Tecidual/métodos , Alicerces Teciduais , Perda do Osso Alveolar/cirurgia , Processo Alveolar/fisiopatologia , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/uso terapêutico , Substitutos Ósseos/química , Substitutos Ósseos/uso terapêutico , Fosfatos de Cálcio/química , Fosfatos de Cálcio/uso terapêutico , Cerâmica/química , Cerâmica/uso terapêutico , Cães , Durapatita/química , Durapatita/uso terapêutico , Mandíbula/fisiopatologia , Minerais/química , Minerais/uso terapêutico , Osteogênese/fisiologia , Poloxâmero/química , Tensoativos/química , Fatores de Tempo , Alicerces Teciduais/química , Transplante Homólogo
5.
Ann N Y Acad Sci ; 1078: 364-7, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17114742

RESUMO

Between June 2002 and July 2003, 987 fleas, representing four species, and 1019 ticks, representing one argasid and eight ixodid species, were collected from Egyptian animals. These arthropods were tested for rickettsial agents using polymerase chain reaction. DNAs from Anaplasma and Ehrlichia spp. were detected in 13 ticks. Previously undescribed Bartonella spp. were detected in 21 fleas. Coxiella burnetii was detected in two fleas and 20 ticks. Rickettsia typhi was detected in 27 fleas from 10 cities. Spotted fever group rickettsiae were detected in both fleas and ticks and included Rickettsia aeschlimanii and an unnamed Rickettsia sp.


Assuntos
Artrópodes/microbiologia , Sifonápteros/microbiologia , Anaplasma/genética , Anaplasma/isolamento & purificação , Animais , Bartonella/genética , Bartonella/isolamento & purificação , DNA Bacteriano/genética , DNA Bacteriano/isolamento & purificação , Egito , Ehrlichia/genética , Ehrlichia/isolamento & purificação , Geografia , Reação em Cadeia da Polimerase , Densidade Demográfica , Rickettsia/genética , Rickettsia/isolamento & purificação
6.
Exp Appl Acarol ; 40(1): 67-81, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-17004028

RESUMO

To assess the presence of rickettsial pathogens in ticks from Egypt, we collected ticks from domestic and peridomestic animals between June 2002 and July 2003. DNA extracts from 1019 ticks were tested, using PCR and sequencing, for Anaplasma spp., Bartonella spp., Coxiella burnetii, Ehrlichia spp., and Rickettsia spp. Ticks included: 29 Argas persicus, 10 Hyalomma anatolicum anatolicum, 55 Hyalomma anatolicum excavatum, 174 Hyalomma dromedarii, 2 Hyalomma impeltatum, 3 Hyalomma marginatum rufipes, 55 unidentified nymphal Hyalomma, 625 Rhipicephalus (Boophilus) annulatus, 49 Rhipicephalus sanguineus, and 17 Rhipicephalus turanicus. Ticks were collected predominantly (>80%) from buffalo, cattle, and camels, with smaller numbers from chicken and rabbit sheds, sheep, foxes, a domestic dog, a hedgehog, and a black rat. We detected Anaplasma marginale, Coxiella burnetii, Rickettsia aeschlimannii, and four novel genotypes similar to: "Anaplasma platys," Ehrlichia canis, Ehrlichia spp. reported from Asian ticks, and a Rickettsiales endosymbiont of Ixodes ricinus.


Assuntos
Animais Domésticos/parasitologia , Rickettsia/isolamento & purificação , Doenças Transmitidas por Carrapatos/microbiologia , Carrapatos/microbiologia , Animais , Sequência de Bases , DNA Bacteriano/química , DNA Bacteriano/genética , Egito , Feminino , Masculino , Reação em Cadeia da Polimerase/veterinária , Polimorfismo de Fragmento de Restrição , RNA Ribossômico 16S/química , RNA Ribossômico 16S/genética , RNA Ribossômico 18S/química , RNA Ribossômico 18S/genética , Rickettsia/genética , População Rural
7.
Am J Trop Med Hyg ; 75(1): 41-8, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16837707

RESUMO

Serologic surveys in Egypt have documented human and animal exposure to vector-borne bacterial pathogens, but the presence and distribution of these agents in arthropods has not been determined. Between July 2002 and July 2003, fleas were collected from 221 mammals trapped in 17 cities throughout Egypt. A total of 987 fleas were collected, representing four species (Ctenocephalides felis, Echidnophaga gallinacea, Leptopsylla segnis, and Xenopsylla cheopis); 899 of these fleas were X. cheopis from rats (Rattus spp.). Fleas were tested for DNA from Anaplasma spp., Bartonella spp., Coxiella burnetii, Ehrlichia spp., Rickettsia spp., and Yersinia pestis. Rickettsia typhi, the agent of murine typhus, was detected in X. cheopis and L. segnis from rats from nine cities. A spotted-fever group Rickettsia sp. similar to "RF2125" was detected in E. gallinacea, and two unidentified spotted fever group Rickettsia were detected in two X. cheopis. Novel Bartonella genotypes were detected in X. cheopis and L. segnis from three cities. Coxiella burnetii was detected in two fleas. Anaplasma, Ehrlichia, and Y. pestis were not detected.


Assuntos
Bactérias Gram-Negativas/isolamento & purificação , Infecções por Bactérias Gram-Negativas/epidemiologia , Insetos Vetores/microbiologia , Mamíferos/parasitologia , Sifonápteros/microbiologia , Animais , Primers do DNA/química , Sondas de DNA/química , Egito/epidemiologia , Feminino , Bactérias Gram-Negativas/classificação , Infecções por Bactérias Gram-Negativas/transmissão , Insetos Vetores/classificação , Masculino , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase , Vigilância da População , Ratos , Sifonápteros/classificação
8.
J Parasitol ; 92(2): 313-8, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16729688

RESUMO

We collected 1,023 lice, representing 5 species, from rats and domestic cattle throughout 13 governorates in Egypt and tested these lice for Anaplasma marginale, Bartonella spp., Brucella spp., Borrelia recurrentis, Coxiella burnetii, Francisella tularensis, and Rickettsia spp. by PCR amplification and sequencing. Five different louse-borne bacterial agents were detected in lice from rodents or cattle, including "Bartonella rattimassiliensis", "B. phoceensis", and Bartonella sp. near Bartonella tribocorum, Coxiella burnetii, and Rickettsia typhi. More lice from governorates bordering the Mediterranean and Red Seas contained pathogens. Our data indicate that lice of urban and domestic animals harbor pathogenic or potentially pathogenic bacterial agents throughout Egypt.


Assuntos
Bactérias/isolamento & purificação , Infecções Bacterianas/transmissão , Insetos Vetores/microbiologia , Infestações por Piolhos/veterinária , Ftirápteros/microbiologia , Animais , Bactérias/genética , Bactérias/patogenicidade , Bartonella/genética , Bartonella/isolamento & purificação , Bartonella/patogenicidade , Bovinos , Doenças dos Bovinos/parasitologia , Doenças dos Bovinos/transmissão , Coxiella burnetii/genética , Coxiella burnetii/isolamento & purificação , Coxiella burnetii/patogenicidade , DNA Bacteriano/análise , Egito , Humanos , Infestações por Piolhos/parasitologia , Reação em Cadeia da Polimerase , Ratos , Rickettsia typhi/genética , Rickettsia typhi/isolamento & purificação , Rickettsia typhi/patogenicidade , Doenças dos Roedores/parasitologia , Doenças dos Roedores/transmissão , Análise de Sequência de DNA
9.
J Med Entomol ; 42(6): 1063-7, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16465749

RESUMO

To meet the need for high-throughput sample testing, DNA extraction kits based on the 96-well plate format have been developed for use with blood and tissue samples. These methods have not been applied to DNA extractions from ticks. To meet this need, we developed a high-throughput method for DNA extraction and polymerase chain reaction (PCR) testing of tick samples. A liquid-handling robot was used to extract DNA in a 96-well binding column plate with vacuum manifold. The quantity, purity, and quality of DNA recovered from Ixodes scapularis Say, 1821 nymphs with this method were reproducible and comparable with existing manual DNA extraction techniques. The DNA yield from pools of five nymphal ticks averaged 0.432 +/- 0.04 microg (95% CI). The robot also prepared real-time PCR reactions in 96-well plates, directly from the extracted DNA. A modification of the existing P20 tool resulted in accurate pipetting of 1- to 2-microl volumes with a reproducibility of +/- 0.038 microl when dispensing 1.0 microl. By using this process, 96 samples can be extracted and tested while reducing human labor to approximately 30 min.


Assuntos
Vetores Aracnídeos/genética , DNA/isolamento & purificação , Ixodes/genética , Reação em Cadeia da Polimerase/instrumentação , Robótica/instrumentação , Robótica/métodos , Animais , DNA/química , Humanos , Biologia Molecular/instrumentação , Biologia Molecular/métodos , Reação em Cadeia da Polimerase/métodos , Reprodutibilidade dos Testes , Rickettsia rickettsii/genética , Rickettsia rickettsii/isolamento & purificação
10.
J Neurosurg ; 101(3): 365-76, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15352592

RESUMO

OBJECT: Brachial plexus injuries (BPIs) are often devastating events that lead to upper-extremity paralysis, rendering the limb a painful extraneous appendage. Fortunately, there are several nerve repair techniques that provide restoration of some function. Although there is general agreement in the medical community concerning which patients may benefit from surgical intervention, the actual repair technique for a given lesion is less clear. The authors sought to identify and better define areas of agreement and disagreement among experienced peripheral nerve surgeons as to the management of BPIs. METHODS: The authors developed a detailed survey in two parts: one part addressing general issues related to BPI and the other presenting four clinical cases. The survey was mailed to 126 experienced peripheral nerve physicians and 49 (39%) participated in the study. The respondents represent 22 different countries and multiple surgical subspecialties. They performed a mean of 33 brachial plexus reconstructions annually. Areas of significant disagreement included the timing and indications for surgical intervention in birth-related palsy, treatment of neuroma-in-continuity, the best transfers to achieve elbow flexion and shoulder abduction, the use of intra- or extraplexal donors for motor neurotization, and the use of distal or proximal coaptation during nerve transfer. CONCLUSIONS: Experienced peripheral nerve surgeons disagree in important ways as to the management of BPI. The decisions made by the various treating physicians underscore the many areas of disagreement regarding the treatment of BPI, including the diagnostic approach to defining the injury, timing of and indications for surgical intervention in birth-related palsy, the treatment of neuroma-in-continuity, the choice of nerve transfers to achieve elbow flexion and shoulder abduction, the use of intra- or extraplexal donors for neurotization, and the use of distal or proximal coaptation during nerve transfer.


Assuntos
Braço/inervação , Plexo Braquial/lesões , Contusões/cirurgia , Microcirurgia/métodos , Músculo Esquelético/inervação , Paresia/cirurgia , Complicações Pós-Operatórias/reabilitação , Ombro/inervação , Entorses e Distensões/cirurgia , Atividades Cotidianas/classificação , Adolescente , Adulto , Traumatismos do Nascimento/fisiopatologia , Traumatismos do Nascimento/cirurgia , Plexo Braquial/fisiopatologia , Plexo Braquial/cirurgia , Contusões/fisiopatologia , Coleta de Dados , Eletromiografia , Seguimentos , Humanos , Lactente , Recém-Nascido , Pessoa de Meia-Idade , Neurônios Motores/fisiologia , Transferência de Nervo/métodos , Neuroma/fisiopatologia , Neuroma/cirurgia , Avaliação de Resultados em Cuidados de Saúde , Avaliação de Processos e Resultados em Cuidados de Saúde , Paresia/fisiopatologia , Neoplasias do Sistema Nervoso Periférico/cirurgia , Reabilitação Vocacional , Raízes Nervosas Espinhais/lesões , Raízes Nervosas Espinhais/cirurgia , Entorses e Distensões/fisiopatologia
11.
Cancer Chemother Pharmacol ; 54(4): 361-7, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15197484

RESUMO

PURPOSE: To investigate the ability of systemically delivered BCNU to enhance the activity of either systemically delivered irinotecan (CPT-11) or locally delivered camptothecin from a biodegradable polymer for treatment of an intracranial 9L gliosarcoma. METHODS: We used a single systemic dose of BCNU on treatment day 1 in combination with systemic doses of CPT-11 on treatment days 1-5 and 8-12 against an intracranial rat 9L gliosarcoma model implanted into female Fischer 344 rats. We also used the same systemic dose of BCNU given on treatment day 1, followed by a local dose of a 20% loaded camptothecin biodegradable polymer implanted on the same day. RESULTS: Two doses of CPT-11 (10 and 60 mg/kg) were delivered systemically against intracranial 9L. Neither dose showed an increase in survival compared to controls ( P>0.2 for 10 mg/kg and P=0.17 for 60 mg/kg). Systemic delivery of CPT-11 (10 mg/kg per day) in combination with systemic BCNU (15 mg/kg) did not show a significant effect on survival compared to systemic BCNU alone ( P>0.2), even at the maximally tolerated systemic dose of CPT-11 (60 mg/kg per day; P=0.06). The combination of systemic BCNU (15 mg/kg) and intracranial delivery of camptothecin (20% loaded polymer), however, significantly extended survival compared to systemic BCNU alone ( P<0.001) and compared to intracranial delivery of camptothecin alone ( P=0.01). CONCLUSIONS: In a 9L gliosarcoma model, systemic delivery of CPT-11 showed no benefit in survival when delivered alone or in combination with systemic BCNU, because CPT-11 is unable to cross the blood-brain barrier in cytotoxic levels. When cytotoxic levels of a topoisomerase I inhibitor are delivered directly to the brain tumor via a biodegradable polymer, however, the systemic delivery of the alkylating agent BCNU significantly enhances the antitumor effects of camptothecin in a 9L gliosarcoma model.


Assuntos
Neoplasias Encefálicas/metabolismo , Camptotecina/análogos & derivados , Camptotecina/farmacocinética , Carmustina/farmacologia , Gliossarcoma/metabolismo , Animais , Camptotecina/administração & dosagem , Linhagem Celular Tumoral , Inibidores Enzimáticos/administração & dosagem , Inibidores Enzimáticos/metabolismo , Feminino , Irinotecano , Transplante de Neoplasias , Ratos , Ratos Endogâmicos F344 , Inibidores da Topoisomerase I
12.
J Neurooncol ; 56(3): 209-17, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12061726

RESUMO

Camptothecin is a potent antineoplastic agent that has shown efficacy against multiple tumor lines in vitro; unfortunately, systemic toxicity has limited its in vivo efficacy. This is the first study to investigate the release, biodistribution, and efficacy of camptothecin from a biodegradable polyanhydride polymer. Tritiated camptothecin was incorporated into biodegradable polymers that were implanted intracranially in 16 male Fischer 344 rats and the animals were followed up to 21 days post-implant. A concentration of 11-45 microg of camptothecin-sodium/mg brain tissue was within a 3 mm radius of the polymer disc, with levels of 0.1 microg at the outermost margin of the rat brain, 7 mm from the site of implantation. These tissue concentrations are within the therapeutic ranges for human and rat glioma lines tested against camptothecin-sodium in vitro. The in vivo efficacy of camptothecin-sodium was evaluated with male Fischer 344 rats implanted intracranially with 9L gliosarcoma and compared with the efficacy of 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU). The animals were divided into four groups. Group 1 (control) had a median survival of 17 days. Group 2 (3.8% BCNU polymer) had a median survival of 23 days (P = 0.006). Group 3 (20% camptothecin polymer) had a median survival of 25 days (P = 0.023). Group 4 (50% camptothecin polymer) had a median survival of 69 days (P < 0.001). Drug loadings of 20% and 50% camptothecin released intact camptothecin for up to 1000 h in vitro. We conclude that the biodegradable polymer p(CPP: SA) releases camptothecin-sodium, produces tumoricidal tissue levels, results in little or no systemic toxicity, and prolongs survival in a rat glioma model.


Assuntos
Antineoplásicos Fitogênicos/farmacocinética , Neoplasias Encefálicas/tratamento farmacológico , Camptotecina/farmacocinética , Gliossarcoma/tratamento farmacológico , Animais , Antineoplásicos Fitogênicos/administração & dosagem , Antineoplásicos Fitogênicos/uso terapêutico , Neoplasias Encefálicas/metabolismo , Camptotecina/administração & dosagem , Camptotecina/uso terapêutico , Implantes de Medicamento , Gliossarcoma/metabolismo , Cinética , Masculino , Ratos , Ratos Endogâmicos F344 , Análise de Sobrevida , Fatores de Tempo , Distribuição Tecidual
13.
J Biol Chem ; 277(19): 16968-75, 2002 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-11877387

RESUMO

UDP-glucuronate decarboxylase (UGD) catalyzes the formation of UDP-xylose from UDP-glucuronate. UDP-xylose is then used to initiate glycosaminoglycan biosynthesis on the core protein of proteoglycans. In a yeast two-hybrid screen with the protein kinase Akt (protein kinase B), we detected interactions with a novel sequence, which we cloned and expressed. The expressed protein displayed UGD activity but did not display the activities of homologous nucleotide sugar epimerases or dehydratases. We did not detect phosphorylation of UGD by Akt nor did we detect any influence of Akt on UGD activity. Effects of UGD on Akt kinase activity were also absent. Northern blot and Western blot analyses revealed the presence of UGD in multiple tissues and brain regions. Subcellular studies and histochemistry localized UGD protein to the perinuclear Golgi where xylosylation of proteoglycan core proteins is known to occur.


Assuntos
Carboxiliases/biossíntese , Carboxiliases/genética , Proteínas Serina-Treonina Quinases , Sequência de Aminoácidos , Animais , Sequência de Bases , Northern Blotting , Western Blotting , Encéfalo/metabolismo , Carboxiliases/química , Linhagem Celular , Cromatografia Líquida de Alta Pressão , Clonagem Molecular , DNA Complementar/metabolismo , Biblioteca Gênica , Glutationa Transferase/metabolismo , Complexo de Golgi/metabolismo , Humanos , Espectrometria de Massas , Modelos Químicos , Dados de Sequência Molecular , Fosforilação , Ligação Proteica , Proteoglicanas/química , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-akt , Ratos , Homologia de Sequência de Aminoácidos , Espectrometria de Massas por Ionização por Electrospray , Frações Subcelulares/metabolismo , Fatores de Tempo , Distribuição Tecidual , Transfecção , Técnicas do Sistema de Duplo-Híbrido , UDPglucose 4-Epimerase/metabolismo
14.
Proc Natl Acad Sci U S A ; 99(6): 4061-6, 2002 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-11904450

RESUMO

In the penis, nitric oxide (NO) can be formed by both neuronal NO synthase and endothelial NOS (eNOS). eNOS is activated by viscous drag/shear stress in blood vessels to produce NO continuously, a process mediated by the phosphatidylinositol 3-kinase (PI3kinase)/Akt pathway. Here we show that PI3-kinase/Akt physiologically mediates erection. Both electrical stimulation of the cavernous nerve and direct intracavernosal injection of the vasorelaxant drug papaverine cause rapid increases in phosphorylated (activated) Akt and eNOS. Phosphorylation is diminished by wortmannin and LY294002, inhibitors of PI3-kinase, the upstream activator of Akt. The two drugs also reduce erection. Penile erection elicited by papaverine is reduced profoundly in mice with targeted deletion of eNOS. Our findings support a model in which rapid, brief activation of neuronal NOS initiates the erectile process, whereas PI3-kinase/Akt-dependent phosphorylation and activation of eNOS leads to sustained NO production and maximal erection.


Assuntos
Óxido Nítrico Sintase/metabolismo , Ereção Peniana , Pênis/enzimologia , Proteínas Serina-Treonina Quinases , Proteínas Proto-Oncogênicas/metabolismo , Androstadienos/farmacologia , Animais , Cromonas/farmacologia , Estimulação Elétrica , Endotélio/efeitos dos fármacos , Endotélio/enzimologia , Endotélio/inervação , Endotélio/metabolismo , Ativação Enzimática/efeitos dos fármacos , Masculino , Modelos Biológicos , Morfolinas/farmacologia , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo I , Óxido Nítrico Sintase Tipo III , Papaverina/farmacologia , Ereção Peniana/efeitos dos fármacos , Pênis/efeitos dos fármacos , Pênis/inervação , Pênis/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase , Fosforilação/efeitos dos fármacos , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-akt , Ratos , Ratos Sprague-Dawley , Wortmanina
15.
Nature ; 415(6871): 541-4, 2002 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-11823862

RESUMO

Phospholipase C gamma 1 (PLC-gamma 1) hydrolyses phosphatidylinositol-4,5-bisphosphate to the second messengers inositol-1,4,5-trisphosphate and diacylglycerol. PLC-gamma 1 also has mitogenic activity upon growth-factor-dependent tyrosine phosphorylation; however, this activity is not dependent on the phospholipase activity of PLC-gamma 1, but requires an SH3 domain. Here, we demonstrate that PLC-gamma 1 acts as a guanine nucleotide exchange factor (GEF) for PIKE (phosphatidylinositol-3-OH kinase (PI(3)K) enhancer). PIKE is a nuclear GTPase that activates nuclear PI(3)K activity, and mediates the physiological activation by nerve growth factor (NGF) of nuclear PI(3)K activity. This enzymatic activity accounts for the mitogenic properties of PLC-gamma 1.


Assuntos
Proteínas de Ligação ao GTP/metabolismo , Fatores de Troca do Nucleotídeo Guanina/fisiologia , Isoenzimas/fisiologia , Fosfolipases Tipo C/fisiologia , Proteínas ras/metabolismo , Animais , Ativação Enzimática , Mitógenos/fisiologia , Proteínas Monoméricas de Ligação ao GTP , Células PC12 , Fosfatidilinositol 3-Quinases/metabolismo , Fosfolipase C gama , Ligação Proteica , Ratos , Proteínas Recombinantes de Fusão/metabolismo , Domínios de Homologia de src
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