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1.
Cell ; 185(10): 1661-1675.e16, 2022 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-35483373

RESUMO

ß-arrestins bind G protein-coupled receptors to terminate G protein signaling and to facilitate other downstream signaling pathways. Using single-molecule fluorescence resonance energy transfer imaging, we show that ß-arrestin is strongly autoinhibited in its basal state. Its engagement with a phosphopeptide mimicking phosphorylated receptor tail efficiently releases the ß-arrestin tail from its N domain to assume distinct conformations. Unexpectedly, we find that ß-arrestin binding to phosphorylated receptor, with a phosphorylation barcode identical to the isolated phosphopeptide, is highly inefficient and that agonist-promoted receptor activation is required for ß-arrestin activation, consistent with the release of a sequestered receptor C tail. These findings, together with focused cellular investigations, reveal that agonism and receptor C-tail release are specific determinants of the rate and efficiency of ß-arrestin activation by phosphorylated receptor. We infer that receptor phosphorylation patterns, in combination with receptor agonism, synergistically establish the strength and specificity with which diverse, downstream ß-arrestin-mediated events are directed.


Assuntos
Fosfopeptídeos , Receptores Acoplados a Proteínas G , Fosfopeptídeos/metabolismo , Fosforilação , Receptores Acoplados a Proteínas G/metabolismo , beta-Arrestina 1/metabolismo , beta-Arrestinas/metabolismo
2.
Nature ; 547(7661): 68-73, 2017 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-28607487

RESUMO

G-protein-coupled receptor (GPCR)-mediated signal transduction is central to human physiology and disease intervention, yet the molecular mechanisms responsible for ligand-dependent signalling responses remain poorly understood. In class A GPCRs, receptor activation and G-protein coupling entail outward movements of transmembrane helix 6 (TM6). Here, using single-molecule fluorescence resonance energy transfer imaging, we examine TM6 movements in the ß2 adrenergic receptor (ß2AR) upon exposure to orthosteric ligands with different efficacies, in the absence and presence of the Gs heterotrimer. We show that partial and full agonists differentially affect TM6 motions to regulate the rate at which GDP-bound ß2AR-Gs complexes are formed and the efficiency of nucleotide exchange leading to Gs activation. These data also reveal transient nucleotide-bound ß2AR-Gs species that are distinct from known structures, and provide single-molecule perspectives on the allosteric link between ligand- and nucleotide-binding pockets that shed new light on the G-protein activation mechanism.


Assuntos
Subunidades alfa Gs de Proteínas de Ligação ao GTP/metabolismo , Receptores Adrenérgicos beta 2/metabolismo , Imagem Individual de Molécula , Agonistas de Receptores Adrenérgicos beta 2/química , Agonistas de Receptores Adrenérgicos beta 2/metabolismo , Agonistas de Receptores Adrenérgicos beta 2/farmacologia , Sítio Alostérico , Membrana Celular/metabolismo , Clembuterol/química , Clembuterol/metabolismo , Clembuterol/farmacologia , Ativação Enzimática/efeitos dos fármacos , Epinefrina/química , Epinefrina/metabolismo , Epinefrina/farmacologia , Transferência Ressonante de Energia de Fluorescência , Subunidades alfa Gs de Proteínas de Ligação ao GTP/química , Guanosina Difosfato/metabolismo , Humanos , Cinética , Ligantes , Modelos Moleculares , Movimento/efeitos dos fármacos , Estabilidade Proteica , Receptores Adrenérgicos beta 2/química
3.
Aging Clin Exp Res ; 32(4): 747-753, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31267377

RESUMO

PURPOSE OR OBJECTIVE: To evaluate toxicity and outcomes of moderately hypofractionated helical tomotherapy for the curative treatment of a cohort of patients aged ≥ 75 years with localized prostate cancer (PC). MATERIALS AND METHODS: From January 2013 to February 2017, 95 patients with median age 77 years (range 75-88) were treated for PC. 39% were low risk, 33% intermediate risk (IR), 28% high risk (HR). Median iPSA was 9.42 ng/ml (1.6-107). Androgen deprivation was prescribed according to NCCN recommendations. All patients received 70 Gy in 28 fractions to the prostate; 61.6 Gy were delivered to the seminal vesicles for IR; whole pelvis irradiation with a total dose of 50.4 Gy was added in the HR group. Toxicity evaluation was based on CTCAE V4.0 criteria, biochemical failure was defined following Phoenix criteria. Quality of Life was assessed with the EPIC-26 index. Overall survival and biochemical failure-free survival were analysed with Kaplan-Meier method. RESULTS: With a median follow-up of 36 months (range 24-73), acute and late toxicity were acceptable. No correlation between toxicity patterns and clinical or dosimetric parameter was registered. EPIC-26 showed a negligible difference in urinary and bowel function post-treatment that did not reach statistical significance. The 2- and 3-years OS were 93% and 87% with cancer specific survival of 97.9% and 96.2%. CONCLUSION: Moderate hypofractionated RT reported excellent outcomes in our cohort of older patients. Shorter schedules may be proposed regardless of chronological age facilitating the treatment compliance in the older population.


Assuntos
Neoplasias da Próstata/terapia , Radioterapia de Intensidade Modulada/efeitos adversos , Idoso , Idoso de 80 Anos ou mais , Antagonistas de Androgênios/uso terapêutico , Estudos de Coortes , Humanos , Masculino , Pessoa de Meia-Idade , Qualidade de Vida , Resultado do Tratamento
4.
Tijdschr Psychiatr ; 61(12): 862-878, 2019.
Artigo em Holandês | MEDLINE | ID: mdl-31907901

RESUMO

BACKGROUND: Aggression after acquired brain injury has a major impact on daily functioning for the patient, their family, and caregivers.
AIM: To present the prevalence and manifestations of aggression in patients with different types of brain injury.
METHOD: Systematic search of the literature in PubMed, Psycinfo and Embase.
RESULTS: Fourty-one studies were included in which 15 different outcome measures for aggression were used. The prevalence of agitation ranged between 4.0%-93.9% (median 35.8%), of aggression between 3.7%-88.0% (median 35.3%) and of hostility between 4.0%-45.7% (median 9.1%). Prevalence rates were highest in patients with traumatic brain injury. Verbal aggression occurred more frequently (median 33.0%, 14.0%-70.0%) than physical aggression (median 11.5%, 1.5%-33.8%), but manifestations of aggression were only examined in ten studies.
CONCLUSION: Aggression is a common behavioral problem after brain injury. The prevalence varies and depends on the type of brain injury, the specific target behavior and the outcome measure. It is recommended to reach consensus on definitions and outcome measures.


Assuntos
Agressão , Lesões Encefálicas/complicações , Lesões Encefálicas/psicologia , Agressão/psicologia , Humanos , Prevalência , Comportamento Problema , Resultado do Tratamento
5.
Cell Mol Neurobiol ; 38(4): 777-782, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-28894964

RESUMO

Pericytes are defined by their anatomical location encircling blood vessels' walls with their long projections. The exact embryonic sources of cerebral pericytes remain poorly understood, especially because of their recently revealed diversity. Yamamoto et al. (Sci Rep 7(1):3855, 2017) using state-of-the-art techniques, including several transgenic mice models, reveal that a subpopulation of brain pericytes are derived from phagocytic macrophages during vascular development. This work highlights a new possible ancestor of brain pericytes. The emerging knowledge from this research may provide new approaches for the treatment of several neurodevelopmental disorders in the future.


Assuntos
Encéfalo/patologia , Macrófagos/patologia , Transtornos do Neurodesenvolvimento/patologia , Pericitos/patologia , Animais , Encéfalo/irrigação sanguínea , Humanos , Camundongos Transgênicos , Transtornos do Neurodesenvolvimento/diagnóstico
6.
Fish Shellfish Immunol ; 82: 504-513, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30170109

RESUMO

Nanoparticle-based delivery technologies have played a central role in a wide variety of applications, including cell therapy, gene transformation, and cellular delivery of molecular dyes. This work synthesized via ionic exchange a nanoparticle consisting of zinc-layered hydroxychloride coupled with yeast ß-glucan (ZG), whose cellular immune response was evaluated using fish spleen leukocytes. Leukocytes from the marine Pacific red snapper (Lutjanus peru) were stimulated with zinc-layered hydroxychloride (ZHC) coupled with yeast ß-glucan (GLU) and challenged with live Vibrio parahaemolyticus after 24 h. Structural characterization of this yeast glucan by proton nuclear magnetic resonance (NMR) indicated structures containing (1-6)-branched (1-3)-ß-D-glucan. The ZHC and ZG were characterized with X-ray diffraction, infrared spectroscopy, scanning electron microscopy and thermogravimetric analysis. The results of the immunological study showed that ZHC, GLU or ZG were safe for leukocytes because cell viability was higher than 80% compared with DMSO or V. parahaemolyticus exposure. The ZG or GLU treatments enhanced nitric oxide production, superoxide dismutase, catalase and peroxidase activities. Induction of anti- and pro-inflammatory cytokine (IL-1ß, IL-6, IL-8, IL-10, IL-12 and IL-17) genes was more pronounced in ZG or GLU treatments compared to the other groups. Based on the results, ZHC nanoparticles can be used as a delivery carrier of yeast ß-glucan for enhancing immunity in fish and have great potential application in the aquaculture industry.


Assuntos
Doenças dos Peixes/imunologia , Imunidade Inata/efeitos dos fármacos , Perciformes/imunologia , Fermento Seco/química , beta-Glucanas/química , Animais , Leucócitos/imunologia , Nanopartículas Metálicas/química , Vibrioses/imunologia , Vibrio parahaemolyticus/fisiologia , Fermento Seco/farmacologia , Zinco/química , beta-Glucanas/farmacologia
7.
Nature ; 491(7425): 622-6, 2012 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-23086149

RESUMO

In human cells, cytosolic citrate is a chief precursor for the synthesis of fatty acids, triacylglycerols, cholesterol and low-density lipoprotein. Cytosolic citrate further regulates the energy balance of the cell by activating the fatty-acid-synthesis pathway while downregulating both the glycolysis and fatty-acid ß-oxidation pathways. The rate of fatty-acid synthesis in liver and adipose cells, the two main tissue types for such synthesis, correlates directly with the concentration of citrate in the cytosol, with the cytosolic citrate concentration partially depending on direct import across the plasma membrane through the Na(+)-dependent citrate transporter (NaCT). Mutations of the homologous fly gene (Indy; I'm not dead yet) result in reduced fat storage through calorie restriction. More recently, Nact (also known as Slc13a5)-knockout mice have been found to have increased hepatic mitochondrial biogenesis, higher lipid oxidation and energy expenditure, and reduced lipogenesis, which taken together protect the mice from obesity and insulin resistance. To understand the transport mechanism of NaCT and INDY proteins, here we report the 3.2 Å crystal structure of a bacterial INDY homologue. One citrate molecule and one sodium ion are bound per protein, and their binding sites are defined by conserved amino acid motifs, forming the structural basis for understanding the specificity of the transporter. Comparison of the structures of the two symmetrical halves of the transporter suggests conformational changes that propel substrate translocation.


Assuntos
Transportadores de Ácidos Dicarboxílicos/química , Transportadores de Ácidos Dicarboxílicos/metabolismo , Vibrio cholerae/química , Motivos de Aminoácidos , Sequência de Aminoácidos , Sítios de Ligação , Ácido Cítrico/química , Ácido Cítrico/metabolismo , Cristalografia por Raios X , Transporte de Íons , Modelos Moleculares , Dados de Sequência Molecular , Conformação Proteica , Sódio/química , Sódio/metabolismo , Homologia Estrutural de Proteína , Relação Estrutura-Atividade
8.
Environ Monit Assess ; 187(1): 4123, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25399121

RESUMO

The aim of this work was to evaluate the concentrations of polycyclic aromatic hydrocarbons (PAHs) in soils to which solid shale materials (SSMs) were added as soil conditioners. The SSMs were derived from the Petrosix pyrolysis process developed by Petrobras (Brazil). An improved ultrasonic agitation method was used to extract the PAHs from the solid samples (soils amended with SSMs), and the concentrations of the compounds were determined by gas chromatography coupled to mass spectrometry (GC-MS). The procedure provided satisfactory recoveries, detection limits, and quantification limits. The two-, three-, and four-ring PAHs were most prevalent, and the highest concentration was obtained for phenanthrene (978 ± 19 µg kg(-1) in a pyrolyzed shale sample). The use of phenanthrene/anthracene and fluoranthene/pyrene ratios revealed that the PAHs were derived from petrogenic rather than pyrogenic sources. The measured PAH concentrations did not exceed national or international limit values, suggesting that the use of SSMs as soil conditioners should not cause environmental damage.


Assuntos
Monitoramento Ambiental , Hidrocarbonetos Policíclicos Aromáticos/análise , Eliminação de Resíduos/métodos , Poluentes do Solo/análise , Solo/química , Brasil , Cromatografia Gasosa-Espectrometria de Massas , Incineração , Minerais/análise
9.
Antimicrob Agents Chemother ; 57(9): 4229-4236, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23796930

RESUMO

The need for daily parenteral administration is an important limitation in the clinical use of pentavalent antimonial drugs against leishmaniasis. In this study, amphiphilic antimony(V) complexes were prepared from alkylmethylglucamides (L8 and L10, with carbon chain lengths of 8 and 10, respectively), and their potential for the oral treatment of visceral leishmaniasis (VL) was evaluated. Complexes of Sb and ligand at 1:3 (SbL8 and SbL10) were obtained from the reaction of antimony(V) with L8 and L10, as evidenced by elemental and electrospray ionization-tandem mass spectrometry (ESI-MS) analyses. Fluorescence probing of hydrophobic environment and negative-staining transmission electron microscopy showed that SbL8 forms kinetically stabilized nanoassemblies in water. Pharmacokinetic studies with mice in which the compound was administered by the oral route at 200 mg of Sb/kg of body weight indicated that the SbL8 complex promoted greater and more sustained Sb levels in serum and liver than the levels obtained for the conventional antimonial drug meglumine antimoniate (Glucantime [Glu]). The efficacy of SbL8 and SbL10 administered by the oral route was evaluated in BALB/c mice infected with Leishmania infantum after a daily dose of 200 mg of Sb/kg for 20 days. Both complexes promoted significant reduction in the liver and spleen parasite burdens in relation to those in the saline-treated control group. The extent of parasite suppression (>99.96%) was similar to that achieved after Glu given intraperitoneally at 80 mg of Sb/kg/day. As expected, there was no significant reduction in the parasitic load in the group treated orally with Glu at 200 mg of Sb/(kg day). In conclusion, amphiphilic antimony(V) complexes emerge as an innovative and promising strategy for the oral treatment of VL.

10.
Neuropsychol Rehabil ; 23(2): 202-15, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23106137

RESUMO

The objective of this prospective cohort study was to examine the effectiveness of an outpatient neuropsychological rehabilitation programme for patients with acquired brain injury (ABI) and their relatives. The participants were 26 ABI patients with a mean age of 44.7 (SD 11.7) years and 24 caregivers. Mean time since injury was 3.0 (SD 3.6) years. The intervention consisted of a patient-tailored process-oriented neuropsychological rehabilitation programme focusing on facilitation of the adaptation process. Repeated measurements were taken prior to treatment (T0), directly after treatment (T1) and 6 months later (T2). Primary outcome measures were cognitive failures (CFQ), quality of life (SA-SIP30), and individualised goals (GAS). Patients improved significantly on individualised goals between T0 and T1 (p < .01). This effect retained at T2. There were no significant differences on CFQ and SA-SIP30. The programme had a positive effect on attainment of the patient's individual goals. This was not associated with a higher level of participation or a better quality of life.


Assuntos
Lesões Encefálicas/reabilitação , Terapia Cognitivo-Comportamental/métodos , Medicina de Precisão/métodos , Adulto , Idoso , Análise de Variância , Lesões Encefálicas/psicologia , Doença Crônica , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Terapia Ocupacional , Pacientes Ambulatoriais , Inquéritos e Questionários , Resultado do Tratamento , Adulto Jovem
11.
Tijdschr Psychiatr ; 55(9): 665-75, 2013.
Artigo em Holandês | MEDLINE | ID: mdl-24046245

RESUMO

BACKGROUND: In some Dutch mental health care organisations specific neuropsychiatric departments have been developed for patients with brain injury. AIM: To identify the characteristics of patients with brain injury who form a specific population in mental health care and to determine whether such patients require either specialised care or a special type of care. METHOD: A cross-sectional analysis of typical brain injury inpatients was performed. We noted the age and gender of these patients and recorded any previous periods of inpatient care. We listed patients' impairments, the diagnoses they had been given and the treatment they had received. This inventory formed the basis of our conclusions. RESULTS: The typical clinical patient with brain injury in this setting was a male of 51 years or older, most probably affected by a stroke or traumatic brain injury, admitted for a period of 6 months, many years after the incident. He was mostly referred from home or hospital by a physician and was expected to return home again. A combination of cognitive and psychiatric impairments was often found. Physically the patient had no or only mild disabilities, but societal participation was low and many cognitive-affective disorders were seen. Treatment was relatively infrequent and mostly directed at daily activities. The most frequent diagnosis was & lquo;cognitive deficits not otherwise specified'. Irritability, agitation, apathy and depression were frequent symptoms. CONCLUSION: This inventory suggests that brain injury patients in a mental health care setting need special care which is not available in other health care settings.


Assuntos
Lesões Encefálicas/terapia , Necessidades e Demandas de Serviços de Saúde , Serviços de Saúde Mental/estatística & dados numéricos , Adulto , Idoso , Estudos Transversais , Feminino , Hospitais Psiquiátricos/estatística & dados numéricos , Humanos , Pacientes Internados , Masculino , Transtornos Mentais/epidemiologia , Transtornos Mentais/etiologia , Transtornos Mentais/reabilitação , Pessoa de Meia-Idade , Países Baixos , Adulto Jovem
12.
Nat Commun ; 13(1): 4831, 2022 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-35977933

RESUMO

Both T cells and B cells have been shown to be generated after infection with SARS-CoV-2 yet protocols or experimental models to study one or the other are less common. Here, we generate a chimeric protein (SpiN) that comprises the receptor binding domain (RBD) from Spike (S) and the nucleocapsid (N) antigens from SARS-CoV-2. Memory CD4+ and CD8+ T cells specific for SpiN could be detected in the blood of both individuals vaccinated with Coronavac SARS-CoV-2 vaccine and COVID-19 convalescent donors. In mice, SpiN elicited a strong IFN-γ response by T cells and high levels of antibodies to the inactivated virus, but not detectable neutralizing antibodies (nAbs). Importantly, immunization of Syrian hamsters and the human Angiotensin Convertase Enzyme-2-transgenic (K18-ACE-2) mice with Poly ICLC-adjuvanted SpiN promotes robust resistance to the wild type SARS-CoV-2, as indicated by viral load, lung inflammation, clinical outcome and reduction of lethality. The protection induced by SpiN was ablated by depletion of CD4+ and CD8+ T cells and not transferred by antibodies from vaccinated mice. Finally, vaccination with SpiN also protects the K18-ACE-2 mice against infection with Delta and Omicron SARS-CoV-2 isolates. Hence, vaccine formulations that elicit effector T cells specific for the N and RBD proteins may be used to improve COVID-19 vaccines and potentially circumvent the immune escape by variants of concern.


Assuntos
COVID-19 , SARS-CoV-2 , Animais , Anticorpos Neutralizantes , Anticorpos Antivirais , Linfócitos T CD8-Positivos , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Humanos , Camundongos , Nucleocapsídeo , Proteínas do Nucleocapsídeo , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus
13.
Curr Pharm Des ; 26(6): 650-663, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31878850

RESUMO

Carboxylic acids are an important natural component as a final product or intermediates for syntheses. They are produced in plants, animals and also as products from biotechnological processes. This review presents the use of single hydroxide particles and layered double hydroxides as alternative adsorbents to remove carboxylic acids from liquid media. The proposal to use hydroxide particles is based on its affinity to adsorb or intercalate carboxylic acids. Besides, the change in properties of the adsorbate-sorbate product evinces that this intermediate can be used as a vehicle to transport and release carboxylic acids. Additional examples will also be presented to prove that layered hydroxides are capable of removing non-ionic compounds from wine, milk and tomato. The use of layered compounds to remove active ingredients could reduce the number of separations steps, costs and reduce or eliminate solvents, thus encouraging the design of industrial processes of separation using hydroxides particles.


Assuntos
Ácidos Carboxílicos/isolamento & purificação , Hidróxidos/química , Adsorção
14.
Otolaryngol Head Neck Surg ; 141(3): 395-400, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19716020

RESUMO

OBJECTIVE: To review the results of 78 revision stapedotomies, determining the causes of failure and the predictors of surgical success. STUDY DESIGN: Case series with chart review. SETTING: Tertiary referral center. SUBJECTS AND METHODS: Seventy-eight operations were performed in a tertiary referral center on 72 patients between 1995 and 2005. Indication for surgery was recurrent or persistent conductive hearing loss. RESULTS: The most common causes of failure were prosthesis displacement, incus necrosis, and oval window fibrosis. Postoperative air-bone gap was closed to within 10 dB in 54 percent of cases, and mean postoperative air-bone gap was 13.6 dB. Overclosure occurred in five percent of cases, sensorineural hearing loss in six percent of cases, and we had one postoperative dead ear. Success rates were higher in cases presenting prosthesis or ossicular malfunction than in cases with oval window problems. Hearing results did not differ if the prosthesis was crimped to either the malleus or the remnant of the long incudal process. Outcomes were similar for local or general anesthesia, and the nitinol piston did not significantly improve the hearing results. CONCLUSION: Revision stapedotomy is less successful than primary procedure. Lessening the surgical trauma provides the most favorable results.


Assuntos
Perda Auditiva Condutiva/cirurgia , Otosclerose/cirurgia , Cirurgia do Estribo , Adulto , Idoso , Audiometria de Tons Puros , Feminino , Seguimentos , Audição/fisiologia , Perda Auditiva Condutiva/etiologia , Perda Auditiva Condutiva/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Otosclerose/complicações , Otosclerose/diagnóstico , Otoscopia , Reoperação , Estudos Retrospectivos , Tomografia Computadorizada por Raios X , Falha de Tratamento , Adulto Jovem
15.
Int J Mol Epidemiol Genet ; 10(5): 77-84, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31988698

RESUMO

Studies have shown association of lipoprotein lipase (LPL) polymorphisms with coronary artery disease (CAD); however, limited studies on the genetics of CAD have been done in the Philippines. Because of their effects on high-density lipoprotein and triglyceride metabolism, the G-allele of the Ser447X variant of LPL gene has been shown to be atheroprotective, while HindIII polymorphism has been shown to be pro-atherogenic. We assessed 1301 patients undergoing coronary angiography to determine the prevalence of HindIII and Ser447X polymorphisms and their association with angiographically significant CAD. Genotyping for HindIII and Ser447X variants were analyzed by real-time PCR. Multivariate analyses were performed to determine the interaction between LPL polymorphisms and risk factors of CAD. CAD+ group (72%) was predominantly male (76%) with a mean age of 60.17 ± 11.01 with hypertension (89%), dyslipidemia (84%) and smoking (54%) as the most common risk factors. HindIII carriage frequency among the CAD+ group was 20.3% with a genotypic distribution of 78.71% (T/T), 19.83% (T/G) and 1.46% (G/G). Ser447X carriage frequency among the CAD+ group was 8.0% with a genotypic distribution of 91.39% (C/C), 8.38% (C/G) and 0.23% (G/G). HindIII and Ser447X polymorphisms were both not significantly associated with CAD. LPL polymorphic allele HindIII was common, while Ser447X was rare. Present study did not show association of LPL polymorphisms with the development of CAD. However, among patients with dyslipidemia, presence of Ser447X allele is associated with an increased risk (OR 2.6; 95% CI 2.1-3.7; p value < 0.001) of developing CAD than those without LPL polymorphisms.

16.
Oncogene ; 26(14): 2095-103, 2007 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-17016431

RESUMO

Cyclic adenosine 3'5' monophosphate (cAMP) and protein kinase A (PKA) cooperate with phosphatidylinositol 3' kinase (PI3K) signals in the control of growth and survival. To determine the molecular mechanism(s) involved, we identified and mutagenized a specific serine (residue 83) in p85alpha(PI3K), which is phosphorylated in vivo and in vitro by PKA. Expression of p85alpha(PI3K) mutants (alanine or aspartic substitutions) significantly altered the biological responses of the cells to cAMP. cAMP protection from anoikis was reduced in cells expressing the alanine version p85alpha(PI3K). These cells did not arrest in G1 in the presence of cAMP, whereas cells expressing the aspartic mutant p85D accumulated in G1 even in the absence of cAMP. S phase was still efficiently inhibited by cAMP in cells expressing both mutants. The binding of PI3K to Ras p21 was greatly reduced in cells expressing p85A in the presence or absence of cAMP. Conversely, expression of the aspartic mutant stimulated robustly the binding of PI3K to p21 Ras in the presence of cAMP. Mutation in the Ser 83 inhibited cAMP, but not PDGF stimulation of PI3K. Conversely, the p85D aspartic mutant amplified cAMP stimulation of PI3K activity. Phosphorylation of Ser 83 by cAMP-PKA in p85alpha(PI3K) was also necessary for estrogen signaling as expression of p85A or p85D mutants inhibited or amplified, respectively, the binding of estrogen receptor to p85alpha and AKT phosphorylation induced by estrogens. The data presented indicate that: (1) phosphorylation of Ser 83 in p85alpha(PI3K) is critical for cAMP-PKA induced G1 arrest and survival in mouse 3T3 fibroblasts; (2) this site is necessary for amplification of estrogen signals by cAMP-PKA and related receptors. Finally, these data suggest a general mechanism of PI3K regulation by cAMP, operating in various cell types and under different conditions.


Assuntos
Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , AMP Cíclico/farmacologia , Estrogênios/farmacologia , Fosfatidilinositol 3-Quinases/metabolismo , Transdução de Sinais , Animais , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/genética , Células Cultivadas , Citoproteção , Estrogênios/metabolismo , Fase G1/efeitos dos fármacos , Fase G1/genética , Humanos , Mutação , Fosfatidilinositol 3-Quinases/genética , Fosforilação , Fator de Crescimento Derivado de Plaquetas/farmacologia , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Serina/genética , Serina/metabolismo
17.
Oncogene ; 26(14): 2039-47, 2007 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-17043656

RESUMO

Phosphatidylinositol 3-kinase (PI3K) is necessary for thyroid stimulating hormone (TSH)-induced cell cycle progression. To determine the molecular mechanism linking PI3K to TSH, we have identified a serine residue in p85alpha(PI3K) phosphorylated by protein kinase A (PKA) in vitro and in vivo. Expression of an alanine mutant (p85A) abolished cyclic AMP/TSH-induced cell cycle progression and was lethal in thyroid cells (FRTL-5). The aspartic version of the p85alpha(PI3K) (p85D) inhibited apoptosis following TSH withdrawal. The p85alpha(PI3K) wild type not the p85A bound PKA regulatory subunit RIIbeta in cells stimulated with cAMP or TSH. The binding of the aspartic version of p85alpha(PI3K) to RIIbeta was independent of cAMP or TSH stimulation. Similarly, binding of PI3K to p21Ras and activation of AKT, a downstream PI3K target, were severely impaired in cells expressing the p85A mutant. Finally, we found that the catalytic activity of PI3K was stimulated by TSH in cells expressing the wild-type p85alpha(PI3K) but not in cells expressing p85A. This latter mutant did not affect the epidermal growth factor-stimulated PI3K activity. We suggest that (1) TSH-cAMP-induced PKA phosphorylates p85alpha(PI3K) at serine 83, (2) phosphorylated p85alpha(PI3K) binds RIIbeta-PKA and targets PKAII to the membrane, and (3) PI3K activity and p21Ras binding to PI3K increase and activate PI3K downstream targets. This pathway is essential for the transmission of TSH-cAMP growth signals.


Assuntos
Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , AMP Cíclico/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Tireotropina/metabolismo , Animais , Catálise , Ciclo Celular/genética , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular , Células Cultivadas , Subunidade RIIbeta da Proteína Quinase Dependente de AMP Cíclico , Camundongos , Mutação , Fosfatidilinositol 3-Quinases/genética , Fosforilação , Subunidades Proteicas/genética , Subunidades Proteicas/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Ratos , Serina/genética , Serina/metabolismo , Tireotropina/farmacologia
18.
J Clin Invest ; 107(7): 803-12, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11285299

RESUMO

In agreement with evidence that estrogens slow the rate of bone remodeling by suppressing the production of both osteoclasts and osteoblasts, loss of estrogens leads to an increase in the number of osteoclast as well as early osteoblast progenitors (CFU-osteoblasts; CFU-OBs) in the murine bone marrow. Here we show that CFU-OBs are early transit-amplifying progenitors, i.e., dividing cells capable of limited self-renewal, and that 17 beta-estradiol acts in vivo and in vitro to attenuate their self-renewal by approximately 50%. Consistent with a direct receptor-mediated action of estrogens on early mesenchymal cell progenitors, anti-estrogen receptor-alpha (anti-ER alpha) Ab's stain a small number of marrow cells that exhibit characteristics of primitive undifferentiated cells, including a high nucleus/cytoplasm ratio and lack of lineage-specific biochemical markers; the effect of 17 beta-estradiol on CFU-OB self-renewal is absent in mice lacking ER alpha. Because both osteoblasts and the stromal/osteoblastic cells that are required for osteoclast development are derived from CFU-OBs, suppression of the self-renewal of this common progenitor may represent a key mechanism of the anti-remodeling effects of estrogens.


Assuntos
Células da Medula Óssea/citologia , Estradiol/metabolismo , Osteoblastos/citologia , Células-Tronco/citologia , Animais , Células da Medula Óssea/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Estradiol/farmacologia , Receptor alfa de Estrogênio , Feminino , Cobaias , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Osteoblastos/efeitos dos fármacos , Ratos , Receptores de Estrogênio/biossíntese , Células-Tronco/efeitos dos fármacos
19.
World J Gastroenterol ; 13(45): 6016-21, 2007 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-18023092

RESUMO

AIM: To estimate the prevalence of small intestine bacterial overgrowth (SIBO) among patients with an earlier diagnosis of irritable bowel disease (IBS) in our geographical area, and to collect information on the use of locally acting non-absorbable antibiotics in the management of SIBO. METHODS: A non-interventional study was conducted in 73 consecutive patients with a symptom-based diagnosis. RESULTS: When the patients underwent a "breath test", 33 (45.2%) showed the presence of a SIBO. After treatment with rifaximin 1,200 mg/d for seven days in 32 patients, 19 (59.4%) showed a negative "breath test" one week later as well as a significant reduction of symptoms, thus confirming the relationship between SIBO and many of the symptoms claimed by patients. In the other 13 patients, "breath test" remained positive, and a further cycle of treatment with ciprofloxacin 500 mg/d was given for 7 additional days, resulting in a negative "breath test" in one patient only. CONCLUSION: (1) about half of the patients with a symptomatic diagnosis of IBS have actually SIBO, which is responsible for most of the symptoms attributed to IBS; (2) only a "breath test" with lactulose (or with glucose in subjects with an intolerance to lactose) can provide a differential diagnosis between IBS and SIBO, with almost identical symptoms; and (3) the use of non-absorbable antibiotics may be useful to reduce the degree of SIBO and related symptoms; it must be accompanied, however, by the correction of the wrong alimentary habits underlying SIBO.


Assuntos
Antibacterianos/administração & dosagem , Testes Respiratórios , Enteropatias/tratamento farmacológico , Intestino Delgado/microbiologia , Síndrome do Intestino Irritável/microbiologia , Lactulose/análise , Adolescente , Adulto , Idoso , Diagnóstico Diferencial , Feminino , Humanos , Enteropatias/diagnóstico , Enteropatias/epidemiologia , Enteropatias/microbiologia , Síndrome do Intestino Irritável/diagnóstico , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Prevalência
20.
Parasitol Int ; 66(1): 884-888, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27729245

RESUMO

American tegumentary leishmaniasis (ATL) is a neglected disease widely distributed in Latin America. In Brazil, it is caused by different Leishmania species belonging to the Subgenera Viannia and Leishmania. ATL diagnosis is routinely based on clinical, epidemiological, parasitological and immunological (delayed-type hypersensitivity skin test-DTH) evidences. The main objective of this work was to determine the efficacy of a previous immunohistochemical (IHC) method developed by our group. Seventy eight skin biopsies from patients with different ATL clinical forms and origins were evaluated. The method was previously standardized in ATL patients from the municipality of Caratinga, Minas Gerais, Brazil, all infected with Leishmania (V.) braziliensis. Here, it is evaluated in patients from the North, Southeast and Midwest regions of Brazil. Clinical, parasitological (biopsy PCR) and immunological (Montenegro skin test-MST) diagnosis were performed prior to IHC procedure. The IHC procedure detected 70.5% of the cases having a high agreement with MST diagnosis (kappa=0.84). A distinguished contribution of this work is that IHC succeed in diagnosing some negative DTH patients. Those were infected with Leishmania (L.) amazonensis, commonly causing the anergic form of the disease. In conclusion, IHC succeed in detecting ATL caused by different Leishmania species from various geographic regions and clinical status. Although it was not able to detect ATL in all patients, it was better than MST providing an additional tool for the diagnosis of ATL patients. There was no significant correlation between clinical forms and histological features including the presence of necrosis.


Assuntos
Imuno-Histoquímica , Leishmania/isolamento & purificação , Leishmaniose Cutânea/diagnóstico , Leishmaniose Cutânea/parasitologia , Pele/parasitologia , Adolescente , Adulto , Idoso , Biópsia , Brasil/epidemiologia , Feminino , Humanos , Leishmania/genética , Leishmania/imunologia , Leishmania braziliensis/imunologia , Leishmania braziliensis/isolamento & purificação , Leishmaniose Cutânea/epidemiologia , Fígado/parasitologia , Fígado/patologia , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Pele/patologia , Pele/ultraestrutura , Estados Unidos , Adulto Jovem
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