Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 110
Filtrar
Mais filtros

Tipo de documento
Intervalo de ano de publicação
1.
J Biol Regul Homeost Agents ; 35(2 Suppl. 1): 357-364, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34281333

RESUMO

Surgical techniques of soft and hard oral tissues highly benefited from new technologies such as the Quantic Molecular Resonance (QMR) lancet, the Neodymium-doped Yttrium Aluminum Garnet (Nd:YAG) laser and the Erbium-doped Yttrium Aluminum Garnet (Er:YAG) laser. Increasingly, these technologies replace scalpel, conventional electrosurgery and traditional rotary surgery instruments due to their proven advantages. Features such as reduction of the surgical time, more efficient bleeding control resulting in higher intra-operative visibility and improvement of postoperative course with better Quality of Life score (QoL) are highlighted in numerous studies published in the literature. The thermal rise of tissues during surgical incision, performed with other instruments rather than traditional cold blade scalpels, is not to be ignored by the operator and it must take into consideration first when choosing the surgical instrument and then throughout all the surgical act. Auto-fluorescence (AF) is a property possessed by every cell that exposed to a specific wavelength can absorbance or reflect with peculiar characteristics and its direct examination has been proposed as a non-invasive visual tool for investigation of suspicious changes in oral mucosa. At the limit of our knowledge, few studies have been published in the literature regarding tissue's temperature variations and the interest in Infra-Red temperature detection has been shown in various medicine fields and none of published studies investigated the possible correlation between temperature raise and AF variations. This ex vivo study aims to analyse and compare through the use of a thermal imaging camera and simultaneous detection of AF, the possible correlation between temperature increase and auto-fluorescence.


Assuntos
Terapia a Laser , Lasers de Estado Sólido , Fluorescência , Qualidade de Vida , Instrumentos Cirúrgicos , Temperatura
2.
J Helminthol ; 87(2): 203-11, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22716964

RESUMO

This study aimed to evaluate the helminth parasites of Geophagus proximus from the São José dos Dourados River, a tributary of Paraná River, Ilha Solteira Reservoir, São Paulo State, Brazil. From May 2006 to May 2007, 116 G. proximus specimens were examined and seven different taxa of helminth were collected and identified: proteocephalidean plerocercoids (Cestoda); metacercariae of Austrodiplostomum compactum, Clinostomum heluans and Clinostomum sp. (Trematoda); and Raphidascaris (Sprentascaris) hypostomi, and larvae of Raphidascaris sp. and Contracaecum sp. (Nematoda). All parasites presented the typical aggregated pattern of distribution, as well as the presence of a high number of larval stages, an absence of influence of the host sex and seasonality upon community parameters, as well as a correlation between species richness and host body weight. Moreover, with the exception of A. compactum metacercariae, all helminths found in this study are reported for the first time in G. proximus.


Assuntos
Biodiversidade , Ciclídeos/parasitologia , Doenças dos Peixes/parasitologia , Helmintíase Animal/parasitologia , Helmintos/classificação , Helmintos/isolamento & purificação , Animais , Brasil , Feminino , Masculino , Parasitologia/métodos , Rios
3.
J Psychoactive Drugs ; 53(5): 460-473, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34895091

RESUMO

Indigenous Peoples experience disproportionately higher rates of problematic substance use. These problems are situated in a context of individual and intergenerational trauma from colonization, residential schools, and racist and discriminatory practices, policies, and services. Therefore, substance use interventions need to adopt a trauma-informed approach. We aimed to synthesize and report the current literature exploring the intersection of trauma and substance use interventions for Indigenous Peoples. Fourteen databases were searched using keywords for Indigenous Peoples, trauma, and substance use. Of the 1373 sources identified, 117 met inclusion criteria. Literature on trauma and substance use with Indigenous Peoples has increased in the last 5 years (2012-2016, n = 29; 2017-2021, n = 48), with most literature coming from the United States and Canada and focusing on historical or intergenerational trauma. Few articles focused on intersectional identities such as 2SLGBTQIA+ (n = 4), and none focused on veterans. There were limited sources (n = 25) that reported specific interventions at the intersection of trauma and substance use. These sources advocate for multi-faceted, trauma-informed, and culturally safe interventions for use with Indigenous Peoples. This scoping review illuminates gaps in the literature and highlights a need for research reporting on trauma-informed interventions for substance use with Indigenous Peoples.


Assuntos
Transtornos Relacionados ao Uso de Substâncias , Veteranos , Canadá , Humanos , Povos Indígenas , Grupos Populacionais , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , Transtornos Relacionados ao Uso de Substâncias/terapia , Estados Unidos
4.
J Exp Med ; 174(6): 1347-54, 1991 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-1720807

RESUMO

A murine monoclonal antibody (M31-15) was identified using the penetration-inhibiting assay of a human lung adenocarcinoma cell line (MAC10) and remarkably inhibited the phagokinetic tract motility of various cancer cell lines. The antigen, motility-related protein (MRP-1), recognized by M31-15, was 25- and 28-kD proteins, and M31-15 was used to isolate a cDNA clone from a human breast carcinoma cDNA library. Sequence analysis revealed that MRP-1 had strong similarity with a B cell surface antigen (CD37), a melanoma-associated antigen (ME491), the target of an antiproliferative antibody (TAPA-1), a human tumor-associated antigen (CO-029), and the Sm23 antigen of the trematode parasite Schistosoma mansoni.


Assuntos
Anticorpos Monoclonais/imunologia , Antígenos CD , Antígenos de Superfície/análise , Movimento Celular , Glicoproteínas de Membrana , Proteínas/análise , Adenocarcinoma/imunologia , Sequência de Aminoácidos , Animais , Antígenos de Superfície/genética , Antígenos de Superfície/imunologia , Sequência de Bases , DNA/isolamento & purificação , Epitopos/análise , Humanos , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , Tetraspanina 29 , Células Tumorais Cultivadas
5.
Plant Dis ; 94(11): 1378, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30743641

RESUMO

From the spring of 2003 to the summer of 2006, sweet cherry (Prunus avium) trees in orchards near Lvshun City, in the northeast People's Republic of China, had symptoms suggestive of those caused by Cucumber mosaic virus (CMV; genus Cucumovirus, family Bromoviridae). Symptoms included chlorotic patches or mottling on leaves that were also deformed (4). In April 2006, 20 symptomatic leaves sampled from 10 trees in each of four orchards were assayed for CMV with a CMV-specific antiserum (Agdia Inc., Elkhart, IN) in a double-antibody sandwich-ELISA. Of the 80 symptomatic leaf samples, 27 tested positive for the presence of CMV. CMV was detected in all four orchards, within which incidence varied between 0.5 and 4%. Viral nucleoproteins were purified by differential centrifugation and sucrose density gradient fractionation from symptomatic leaves. Transmission electron microscopy of nucleoproteins revealed isometric particles approximately 30 nm in diameter, which is also typical of CMV. Total RNA was also extracted from 100 mg of symptomatic tissue following a Trizol-based protocol (1). A reverse transcriptase-PCR assay with nucleocapsid gene-specific primers was then used (forward primer 5'-ATGGCGACGTCCTCGTTCA-3'; reverse primer 5'-CATCGTTCCCTTCAAAATAG-3') (3). A PCR product of approximately 633 bp was obtained. The PCR product was cloned and sequenced. The sequence (GenBank Accession No. HM996559) had 95% identity with the RNA-1 sequence from CMV 'Fny' strain in GenBank (Accession No. D00356.1). The People's Republic of China is one of the major producers of sweet cherry in Asia and the spread of CMV in China may cause significant economic losses. Thus, virus-infected material should not be used for propagation and surveys should be undertaken to determine if the aphid vectors capable of transmitting CMV are present (2).To our knowledge, this is the first report of CMV occurring in sweet cherry orchards in the People's Republic of China. References: (1) P. Chomczynski and K. Mackey. Biotechniques 19:942, 1995. (2) F. E. Gildow et al. Phytopathology 98:1233, 2008. (3) T. M. Rizzo and P. Palukaitis. J. Gen. Virol. 70:1, 1989. (4) J. Shang et al. Z. Naturforsch. C 65:73, 2010.

6.
Iran J Vet Res ; 19(4): 262-269, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30774666

RESUMO

Mycobacterium avium subspecies paratuberculosis (MAP), as an obligate intracellular bacterium, causes paratuberculosis (Johne's disease) in ruminants. Plus, MAP has consistently been isolated from Crohn's disease (CD) lesions in humans; a notion implying possible direct causative effect for MAP in CD development. Infections caused by MAP are refractory to treatment and in many cases the treatment does not easily resolve the infection. Studying the molecular mechanisms of host-pathogen interaction is helpful in identifying possible drug targets. In this line, it has already been shown that in macrophages infected with various bacteria, including mycobacteria, micro RNA 21 (miR-21) is upregulated, a change that results in diminished macrophages clearance ability and favours pathogens survival within the cells. However, the molecular mechanism(s) by which the intracellular bacteria induce miR-21 expression is not known. In order to verify possible effects from epigenetic changes induced by intracellular bacteria, we studied the cytosine methylation changes at the transcription start regions of miR-21 in THP-1 macrophages infected with MAP. For this purpose, genomic DNA was extracted from infected cells and the methylation status at the region of interest was evaluated by bisulfite conversion method. Our work showed that MAP directs de-methylation of the cystosines at CpG di-nucleotides in this region, while non-CpG cytosines of this region did not show significant changes. Interestingly, the CpG cytosines that were differentially methylated in the infected macrophages occur at the binding sites of the transcription factors already known to regulate miR-21 expression.

7.
J Clin Invest ; 97(7): 1647-54, 1996 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-8601630

RESUMO

Rat pancreatic AR42J cells possess exocrine and neuroendocrine properties. Activin A induces morphological changes and converts them into neuron-like cells. In activin-treated cells, mRNA for pancreatic polypeptide (PP) but not that for either insulin or glucagon was detected by reverse transcription-PCR. About 25% of the cells were stained by anti-PP antibody. When AR42J cells were incubated with betacellulin, a small portion of the cells were stained positively with antiinsulin and anti-PP antibodies. The effect of betacellulin was dose dependent, being maximal at 2 nM. Approximately 4% of the cells became insulin positive at this concentration, and mRNAs for insulin and PP were detected. When AR42J cells were incubated with a combination of betacellulin and activin A, approximately 10% of the cells became insulin positive. Morphologically, the insulin-positive cells were composed of two types of cells: neuron-like and round-shaped cells. Immunoreactive PP was found in the latter type of cells. The mRNAs for insulin, PP, glucose transporter 2, and glucokinase, but not glucagon, were detected. Depolarizing concentration of potassium, tolbutamide, carbachol, and glucagon-like peptide-1 stimulated the release of immunoreactive insulin. These results indicate that betacellulin and activin A convert amylase-secreting AR42J cells into cells secreting insulin. AR42J cells provide a model system to study the formation of pancreatic endocrine cells.


Assuntos
Amilases/metabolismo , Substâncias de Crescimento/administração & dosagem , Inibinas/administração & dosagem , Insulina/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular , Pâncreas/efeitos dos fármacos , Pâncreas/metabolismo , Ativinas , Animais , Sequência de Bases , Betacelulina , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Primers do DNA/genética , Interações Medicamentosas , Expressão Gênica/efeitos dos fármacos , Insulina/genética , Secreção de Insulina , Ilhotas Pancreáticas/citologia , Ilhotas Pancreáticas/efeitos dos fármacos , Ilhotas Pancreáticas/metabolismo , Dados de Sequência Molecular , Pâncreas/citologia , Polipeptídeo Pancreático/genética , Polipeptídeo Pancreático/metabolismo , Reação em Cadeia da Polimerase , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Proteínas Recombinantes/administração & dosagem
8.
J Clin Invest ; 79(4): 1191-6, 1987 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-2881948

RESUMO

Using a new in vitro procedure of the isolated perfused rat pancreas with vagal innervation, electrical vagal stimulation produced an increase in both insulin and glucagon secretion in proportion to the pulse frequency, but an inhibition in somatostatin release. When atropine was infused, both insulin and glucagon responses to vagal stimulation were partially suppressed, whereas somatostatin release was enhanced. In the presence of hexamethonium, vagal stimulation failed to affect insulin, glucagon, or somatostatin secretion. Propranolol partially blocked both insulin and glucagon responses but did not influence somatostatin response. Phentolamine had no significant effect on release of hormones. Simultaneous administration of propranolol and phentolamine tended to inhibit both insulin and glucagon responses to vagal stimulation. These findings suggest that not only a cholinergic but also a noncholinergic neuron may be involved in vagal regulation of pancreatic hormone secretion and that these neurons may be under the control of preganglionic vagal fibers via nicotinic receptors.


Assuntos
Glucagon/metabolismo , Insulina/metabolismo , Somatostatina/metabolismo , Nervo Vago/fisiologia , Animais , Atropina/farmacologia , Estimulação Elétrica , Compostos de Hexametônio/farmacologia , Técnicas In Vitro , Secreção de Insulina , Masculino , Fentolamina/farmacologia , Propranolol/farmacologia , Ratos , Ratos Endogâmicos
9.
Cancer Gene Ther ; 14(1): 74-81, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16990844

RESUMO

The development of safe and efficient liver-specific gene delivery approaches offers new perspectives for the treatment of liver disease, in particular, liver cancer. We evaluated the therapeutic potential of hepatotropic nanoparticles for gene therapy of liver tumor. These nanoparticles do not contain a viral genome and display the hepatitis B virus L antigen, which is essential to confer hepatic specificity. It has not been shown whether a therapeutic effect could be obtained using L nanoparticles in a human liver tumor xenograft model. Rats bearing human hepatic (NuE) and non-hepatic tumors were injected with L nanoparticles containing a green fluorescent protein (GFP) expression plasmid. GFP expression was observed only in NuE-derived tumors but not in the non-hepatic tumor. The potential for treatment of liver tumors was analyzed using L nanoparticles containing the herpes simplex virus thymidine kinase gene, in conjunction with ganciclovir pro-drug administration. The growth of NuE-derived tumors in L particle-injected rats was significantly suppressed, but not of the non-hepatic tumor control. In summary, this is the first demonstration that nanoparticles could be used for delivery of therapeutic genes with anti-tumor activity into human liver tumors. This intravenous delivery system may be one of the major advantages as compared to many other viral vector systems.


Assuntos
Terapia Genética , Neoplasias Hepáticas/terapia , Animais , Antivirais/administração & dosagem , Linhagem Celular Tumoral , Ganciclovir/administração & dosagem , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Nanopartículas , Ratos , Ratos Endogâmicos F344 , Simplexvirus/enzimologia , Timidina Quinase/genética
10.
Vet Parasitol ; 148(3-4): 360-4, 2007 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-17656022

RESUMO

The present study was carried out in the northwestern region of São Paulo State, Brazil, to determine the anthelmintic resistance status in cattle naturally infected with gastrointestinal nematodes. The anthelmintics tested were levamisole phosphate (Ripercol, Fort Dodge), albendazole sulphoxide (Ricobendazole, Fort Dodge), ivermectin (Ivomec, Merial) and moxidectin (Cydectin, Fort Dodge), administered at the doses recommended by the manufacturers. From April 2002 to May 2004, 25 cattle farms were evaluated. On each farm, steers were divided into treatment and control (not treated) groups based on fecal egg counts (FEC). Between 7 and 10 days after the anthelmintics administration, fecal samples were collected from each animal for post-treatment FEC. Fecal cultures from each group were also prepared for larval identification. After treatment, mean FEC reduction (FECR) in treatment groups (compared with control groups) was assessed on each farm. FECR was lower than 90% on 23 farms after ivermectin treatment. On 19 farms, FECR of 100% was recorded following moxidectin treatment; on the remaining 6, FECR ranged from 90% to 97.2%. After albendazole treatment, FECR was higher than 90% on 20 farms and ranged from 47.4% to 84.6% on other 5. After levamisole treatment, FECR was higher than 90% on 23 farms and equal to 47.4% and 73.7% on other 2 farms. Results indicated the presence of resistant Cooperia spp. and Haemonchus spp., especially to ivermectin; on some farms, resistance to albendazole and levamisole was also observed.


Assuntos
Anti-Helmínticos/farmacologia , Doenças dos Bovinos/tratamento farmacológico , Doenças dos Bovinos/parasitologia , Resistência a Medicamentos , Nematoides/efeitos dos fármacos , Infecções por Nematoides/veterinária , Animais , Brasil , Bovinos , Fezes/parasitologia , Masculino , Infecções por Nematoides/tratamento farmacológico , Infecções por Nematoides/parasitologia , Contagem de Ovos de Parasitas/veterinária
11.
Cancer Res ; 59(18): 4502-5, 1999 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-10493495

RESUMO

Cripto-1 (CR-1), a member of the epidermal growth factor-CFC peptide family, activates the ras/raf/mitogen-activated protein/extracellular signal-regulated kinase/mitogen-activated protein kinase pathway. In the present study, the role of CR-1 in the phosphatidylinositol 3'-kinase (PI3K)/AKT (protein kinase B)/glycogen synthase kinase 3beta (GSK-3beta)-dependent signaling pathway was evaluated in human SiHa cervical carcinoma cells. Our data demonstrate that CR-1 can enhance the tyrosine phosphorylation of the p85 regulatory subunit of PI3K and transiently induce the phosphorylation of AKT in a time- and dose-dependent manner. In addition, CR-1 was found to induce the phosphorylation of GSK-3beta. Phosphorylation of AKT and GSK-3beta by CR-1 can be blocked by LY294002, a specific inhibitor of PI3K, thus leading to apoptosis. Finally, the apoptotic effect of LY294002 can be partially rescued by exogenous CR-1. In summary, our data suggest that human CR-1 may function as a survival factor through a PI3K-dependent signaling pathway involving AKT and GSK-3beta.


Assuntos
Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Fator de Crescimento Epidérmico , Glicoproteínas de Membrana , Proteínas de Neoplasias/fisiologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Serina-Treonina Quinases , Proteínas Proto-Oncogênicas/metabolismo , Cromonas/farmacologia , Meios de Cultura Livres de Soro , Inibidores Enzimáticos/farmacologia , Feminino , Proteínas Ligadas por GPI , Quinase 3 da Glicogênio Sintase , Quinases da Glicogênio Sintase , Substâncias de Crescimento/fisiologia , Humanos , Peptídeos e Proteínas de Sinalização Intercelular , Morfolinas/farmacologia , Fosforilação , Proteínas Proto-Oncogênicas c-akt , Proteínas Recombinantes/metabolismo , Transfecção , Células Tumorais Cultivadas , Neoplasias do Colo do Útero
12.
Biochim Biophys Acta ; 1073(2): 275-84, 1991 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-1826216

RESUMO

The affinities with steroid hormones (alpha-estradiol, ethynylestradiol, progesterone, androsterone, dehydroisoandrosterone and testosterone) were observed for Cohn's fraction IV-1 and V (albumin). It was estimated from the comparison with the binding coefficient K (protein-bound form/free form of hormone) in a 3.5% (w/v) bovine serum albumin (BSA) solution that 40-80% of bound hormone in bovine serum is the BSA-bound form. It becomes clear in a liquid membrane system consisting of a hexane source phase (I), a water phase and a hexane receiving phase (II) that the transport flux of hormone is governed primarily by the partition coefficients between the water/hexane phases. In the case of a hormone with a lower partition coefficient, the uptake process from the hexane phase (I) to the water phase is a rate-determining step in the transport system and the serum proteins accelerate the transport of hormones, while with an increase in the partition coefficient the rate-determining step changes from the uptake step to the release step from the water phase to the hexane phase (II) and the hormone transport is decelerated owing to the significant decrease of free hormone concentration in the aqueous phase by the associated with serum proteins for the system having the restricted amount of hormone in the hexane source phase.


Assuntos
Proteínas Sanguíneas/metabolismo , Hormônios Esteroides Gonadais/sangue , Androsterona/sangue , Animais , Transporte Biológico , Proteínas de Transporte/sangue , Bovinos , Desidroepiandrosterona/sangue , Estradiol/sangue , Etinilestradiol/sangue , Cinética , Progesterona/sangue , Ligação Proteica , Soroalbumina Bovina/metabolismo , Soroglobulinas/metabolismo , Testosterona/sangue
13.
Biochim Biophys Acta ; 1492(1): 285-8, 2000 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-11004502

RESUMO

The cDNA encoding an entire open reading frame of rat betacellulin has been cloned from rat kidney. Expression of this cDNA in COS7 cells showed a significant amount of mitogenic activity in the culture media. Western blotting of the cell lysates suggested that the membrane-anchored precursor was cleaved to release its ectodomain very efficiently.


Assuntos
Substâncias de Crescimento/genética , Peptídeos e Proteínas de Sinalização Intercelular , Células 3T3/efeitos dos fármacos , Sequência de Aminoácidos , Animais , Sequência de Bases , Betacelulina , Células COS , Clonagem Molecular , DNA Complementar/análise , Fator de Crescimento Epidérmico/química , Expressão Gênica , Substâncias de Crescimento/farmacologia , Humanos , Rim/fisiologia , Camundongos , Mitógenos/farmacologia , Dados de Sequência Molecular , Ratos , Homologia de Sequência de Aminoácidos , Células Tumorais Cultivadas
14.
Biochim Biophys Acta ; 1089(2): 244-6, 1991 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-1647213

RESUMO

Two types of cDNAs encoding novel human FGF receptors were isolated. These two cDNAs were found to be closely related to the oncogene bek. Products from these genes were membrane-bound when their cDNAs were transiently expressed in COS cells, whereas products from the regions coding extracellular domains were free of membrane attachment and found in the culture medium.


Assuntos
DNA/genética , Receptores Proteína Tirosina Quinases , Receptores de Superfície Celular/genética , Sequência de Aminoácidos , Sequência de Bases , Western Blotting , Linhagem Celular , Humanos , Dados de Sequência Molecular , Fases de Leitura Aberta , Proteínas Tirosina Quinases/genética , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos , Receptores de Fatores de Crescimento de Fibroblastos , Homologia de Sequência do Ácido Nucleico
15.
Biochim Biophys Acta ; 1218(3): 466-8, 1994 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-8049276

RESUMO

A cDNA coding for human pancreatic ribonuclease was isolated from a pancreas cDNA library and sequenced. This cDNA (1620 bp) includes an entire open reading frame encoding mature protein (128 aa) following a signal peptide (28 aa) as well as 5'- and 3'-untranslated regions.


Assuntos
Hominidae/genética , Ribonuclease Pancreático/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Bovinos/genética , Códon , DNA Complementar/química , Humanos , Camundongos/genética , Dados de Sequência Molecular , Oligodesoxirribonucleotídeos , Ratos/genética , Homologia de Sequência de Aminoácidos , Homologia de Sequência do Ácido Nucleico
16.
Biochim Biophys Acta ; 1261(3): 424-6, 1995 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-7742370

RESUMO

A cDNA coding for human ribonuclease 4 was isolated from a pancreas cDNA library and sequenced. This cDNA (996 bp) includes an entire open reading frame encoding mature protein (119 aa) following signal peptide (28 aa). Expression of mature protein in Escherichia coli showed an apparent molecular mass of about 16 kDa, which was slightly lower than the mature form of human RNase 1, in SDS-PAGE.


Assuntos
DNA Complementar/química , Ribonucleases/genética , Sequência de Aminoácidos , Sequência de Bases , Clonagem Molecular , Escherichia coli/enzimologia , Expressão Gênica , Humanos , Dados de Sequência Molecular , Pâncreas/enzimologia
17.
Cell Death Differ ; 7(2): 189-96, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10713733

RESUMO

Cripto-1 (CR-1) is an epidermal growth factor (EGF)-related protein. CR-1 can inhibit beta-casein and whey acidic protein expression in mouse mammary epithelial cells. The present study demonstrates that CR-1 can induce apoptosis in HC-11 mouse mammary epithelial cells, as measured by bis-benzimide stained nuclei, TUNEL assay and cell death ELISA. Apoptosis could be observed after 2 days of exposure of confluent HC-11 cells to CR-1 in the absence of the survival factors EGF and insulin, with maximum apoptosis occurring at 3 days. A reduction in poly(ADP-ribose) polymerase (PARP) expression and an increase in beta-catenin cleavage was found after 18 h of exposure to CR-1 suggesting that apoptosis was preceded by the induction of a caspase activity since the caspase inhibitor ZFAD.FMK could block the CR-1-induced reduction in PARP expression and CR-1-induced apoptosis. CR-1 was found to increase the expression of caspase-3-like protease. Although, the levels of p27kip1 and p21Bax did not change after exposure to CR-1 for 18 h, the levels of Bcl-xL became undetectable. These studies suggest that CR-1 promotes apoptosis by mediating the induction of caspase-3-like protease and downregulating the expression of Bcl-xL.


Assuntos
Apoptose/efeitos dos fármacos , Fator de Crescimento Epidérmico , Glândulas Mamárias Animais/patologia , Glicoproteínas de Membrana , Proteínas de Neoplasias/farmacologia , Animais , Caspases/metabolismo , Células Cultivadas , Ativação Enzimática/efeitos dos fármacos , Células Epiteliais/patologia , Feminino , Marcação In Situ das Extremidades Cortadas , Glândulas Mamárias Animais/metabolismo , Camundongos , Transdução de Sinais/efeitos dos fármacos
18.
Diabetes ; 48(2): 304-9, 1999 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10334306

RESUMO

Pancreatic AR42J cells have the feature of pluripotency of the common precursor cells of the pancreas. Dexamethasone (Dx) converts them to exocrine cells, whereas activin A (Act) converts them into endocrine cells expressing pancreatic polypeptide. A combination of Act and betacellulin (BTC) converts them further into insulin-secreting cells. The present study identifies some of the genes involved in the process of differentiation that is induced by these factors, using the mRNA differential display and screening of the cDNA expression array. The expression levels of 7 genes were increased by Act alone, and a combination of Act and BTC increased the expression of 25 more genes. Of these, 16 represented known genes or homologues of genes characterized previously. Nine of the identified genes were unrelated to any other sequences in the database. An inhibitor of the mitogen-activated protein kinase pathway, PD098059, which blocks the differentiation into insulin-secreting cells, inhibited the expression of 18 of the 25 genes, suggesting that the proteins encoded by these genes are associated with the differentiation into insulin-producing cells. These include known genes encoding extracellular signaling molecules, such as parathyroid hormone-related peptide, cytoskeletal proteins, and intracellular signaling molecules. Identification and characterization of these differentially expressed genes should help to clarify the molecular mechanism of differentiation of pancreatic cells and the gene products that enable the beta-cells to produce insulin.


Assuntos
Expressão Gênica/fisiologia , Insulina/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular , Pâncreas/metabolismo , Pâncreas/fisiologia , Ativinas , Animais , Betacelulina , Diferenciação Celular/fisiologia , DNA Complementar/genética , Apresentação de Dados , Bases de Dados como Assunto , Combinação de Medicamentos , Inibidores Enzimáticos/farmacologia , Flavonoides/farmacologia , Expressão Gênica/efeitos dos fármacos , Substâncias de Crescimento/farmacologia , Inibinas/farmacologia , Secreção de Insulina , Ilhotas Pancreáticas/citologia , Ilhotas Pancreáticas/metabolismo , Pâncreas/citologia , Pâncreas/efeitos dos fármacos , RNA Mensageiro/genética , Células Tumorais Cultivadas
19.
J Mol Biol ; 300(5): 1297-307, 2000 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-10903870

RESUMO

Eosinophil cationic protein (ECP; RNase 3) is a human ribonuclease found only in eosinophil leukocytes that belongs to the RNase A superfamily. This enzyme is bactericidal, helminthotoxic and cytotoxic to mammalian cells and tissues. The protein has been cloned, heterologously overexpressed, purified and crystallized. Its crystal structure has been determined and refined using data up to 1. 75 A resolution. The molecule displays the alpha+beta folding topology typical for members of the ribonuclease A superfamily. The catalytic active site residues are conserved with respect to other ribonucleases of the superfamily but some differences appear at substrate recognition subsites, which may account, in part, for the low catalytic activity. Most strikingly, 19 surface-located arginine residues confer a strong basic character to the protein. The high concentration of positive charges and the particular orientation of the side-chains of these residues may also be related to the low activity of ECP as a ribonuclease and provides an explanation for its unique cytotoxic role through cell membrane disruption.


Assuntos
Proteínas Sanguíneas/química , Proteína Catiônica de Eosinófilo , Eosinófilos/enzimologia , Ribonucleases/química , Sequência de Aminoácidos , Arginina/metabolismo , Sítios de Ligação , Proteínas Sanguíneas/genética , Proteínas Sanguíneas/metabolismo , Cristalografia por Raios X , Dissulfetos/metabolismo , Proteínas Granulares de Eosinófilos , Escherichia coli , Humanos , Modelos Moleculares , Dados de Sequência Molecular , Estrutura Secundária de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Ribonucleases/genética , Ribonucleases/metabolismo , Alinhamento de Sequência , Eletricidade Estática , Relação Estrutura-Atividade
20.
J Mol Biol ; 285(1): 205-14, 1999 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-9878400

RESUMO

The RNase 4 family is unique among RNase enzymes, displaying the highest level of sequence similarity and encompassing the shortest polypeptide chain. It is the only one showing high specificity. The human representative is an intracellular and plasma enzyme, first isolated from colon adenocarcinoma cell line HT-29. The crystal structures of human recombinant RNase 4, unliganded and in complex with d(Up), have been determined, revealing in the unique active site an explanation for the uridine specificity. Arg101, at a position not involved in catalysis in the other RNase enzymes, penetrates the enzyme moiety shaping the recognition pocket, a flip that is mediated by the interaction with the (shorter chain) C-terminal carboxylate group, providing an anchoring point for the O4 atom of the substrate uridine. The bulky Phe42 side-chain forces Asp80 to be in the chi1=-72.49 degrees rotamer, accepting a hydrogen bond from Thr44, further converting the latter into a hydrogen bond acceptor. This favours an interaction with the -NH-donor group of uridine at position 3 over that with the =N-acceptor of cytidine. The two chemical groups that distinguish uracyl from cytosine are used by the enzyme to discriminate between these two bases.


Assuntos
Endorribonucleases/química , Conformação Proteica , Ribonucleases , Uridina , Sequência de Aminoácidos , Sítios de Ligação , Neurotoxina Derivada de Eosinófilo , Humanos , Ligantes , Dados de Sequência Molecular , Proteínas/química , Ribonuclease Pancreático/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA