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1.
Proc Natl Acad Sci U S A ; 119(48): e2213117119, 2022 11 29.
Artigo em Inglês | MEDLINE | ID: mdl-36413497

RESUMO

There is growing interest in therapeutic intervention that targets disease-relevant RNAs using small molecules. While there have been some successes in RNA-targeted small-molecule discovery, a deeper understanding of structure-activity relationships in pursuing these targets has remained elusive. One of the best-studied tertiary-structured RNAs is the theophylline aptamer, which binds theophylline with high affinity and selectivity. Although not a drug target, this aptamer has had many applications, especially pertaining to genetic control circuits. Heretofore, no compound has been shown to bind the theophylline aptamer with greater affinity than theophylline itself. However, by carrying out a high-throughput screen of low-molecular-weight compounds, several unique hits were identified that are chemically distinct from theophylline and bind with up to 340-fold greater affinity. Multiple atomic-resolution X-ray crystal structures were determined to investigate the binding mode of theophylline and four of the best hits. These structures reveal both the rigidity of the theophylline aptamer binding pocket and the opportunity for other ligands to bind more tightly in this pocket by forming additional hydrogen-bonding interactions. These results give encouragement that the same approaches to drug discovery that have been applied so successfully to proteins can also be applied to RNAs.


Assuntos
Aptâmeros de Nucleotídeos , RNA , RNA/genética , RNA/química , Teofilina/química , Teofilina/metabolismo , Aptâmeros de Nucleotídeos/química , Ligantes , Relação Estrutura-Atividade
2.
Exp Cell Res ; 340(1): 1-11, 2016 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-26254261

RESUMO

Cancer cells often arise progressively from "normal" to "pre-cancer" to "transformed" to "local metastasis" to "metastatic disease" to "aggressive metastatic disease". Recent whole genome sequencing (WGS) and spectral karyotyping (SKY) of cancer cells and tumorigenic models have shown this progression involves three major types of genome rearrangements: ordered small step-wise changes, more dramatic "punctuated evolution" (chromoplexy), and large catastrophic steps (chromothripsis) which all occur in random combinations to generate near infinite numbers of stochastically rearranged metastatic cancer cell genomes. This paper describes a series of mouse cell lines developed sequentially to mimic this type of progression. This starts with the new GhrasT-NIH/Swiss cell line that was produced from the NIH/3T3 cell line that had been transformed by transfection with HRAS oncogene DNA from the T24 human bladder carcinoma. These GhrasT-NIH/Swiss cells were injected s.c. into NIH/Swiss mice to produce primary tumors from which one was used to establish the T1-A cell line. T1-A cells injected i.v. into the tail vein of a NIH/Swiss mouse produced a local metastatic tumor near the base of the tail from which the T2-A cell line was established. T2-A cells injected i.v. into the tail vein of a nude NIH/Swiss mouse produced metastases in the liver and one lung from which the T3-HA (H=hepatic) and T3-PA (P=pulmonary) cell lines were developed, respectively. T3-HA cells injected i.v. into a nude mouse produced a metastasis in the lung from which the T4-PA cell line was established. PCR analysis indicated the human T24 HRAS oncogene was carried along with each in vitro/in vivo transfer step and found in the T2-A and T4-PA cell lines. Light photomicrographs indicate that all transformed cells are morphologically similar. GhrasT-NIH/Swiss cells injected s.c. produced tumors in 4% of NIH/Swiss mice in 6-10 weeks; T1-A cells injected s.c. produced tumors in 100% of NIH/Swiss mice in 7-10 days. T1-A, T-2A, T3-HA and T4-PA cells when injected i.v. into the tail produced local metastasis in non-nude or nude NIH/Swiss mice. T4-PA cells were more widely metastatic than T3-HA cells when injected i.v. into nude mice. Evaluation of the injected mice indicated a general increase in metastatic potential of each cell line in the progression as compared to the GhrasT-NIH/3T3 transformed cells. A new photomicrographic technique to follow growth rates within six preselected 2×2mm(2) grids per plate is described. Average doubling times of the transformed cells GhrasT-NIH/3T3 (17h), T1A (17.5h), T2A (15.5h), T3-HA (17.5h) and T4-PA (18.5h) (average 17.2h) were significantly faster (P=0.006) than NIH Swiss primary embryonic cells and NIH/3T3 cells (22 h each). This cell series is currently used in this lab for studies of cancer cell inhibitors, mitochondrial biogenesis and gene expression and is available for further study by other investigators for intra- and inter-laboratory comparisons of WGS, transcriptome sequencing, SKY and other analyses. The genome rearrangements in these cells together with their phenotypic properties may help provide more insights into how one tumorigenic progression occurred to produce the various cell lines that led to the highly metastatic T4-PA cell line.


Assuntos
Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/patologia , Progressão da Doença , Metástase Neoplásica/genética , Metástase Neoplásica/patologia , Neoplasias da Bexiga Urinária/genética , Neoplasias da Bexiga Urinária/patologia , Animais , Linhagem Celular Tumoral , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/secundário , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/secundário , Camundongos , Camundongos Nus , Células NIH 3T3 , Proteínas Proto-Oncogênicas p21(ras)/genética
3.
Proteins ; 84(3): 316-31, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26650892

RESUMO

Conversion of the primary bile acids cholic acid (CA) and chenodeoxycholic acid (CDCA) to the secondary bile acids deoxycholic acid (DCA) and lithocholic acid (LCA) is performed by a few species of intestinal bacteria in the genus Clostridium through a multistep biochemical pathway that removes a 7α-hydroxyl group. The rate-determining enzyme in this pathway is bile acid 7α-dehydratase (baiE). In this study, crystal structures of apo-BaiE and its putative product-bound [3-oxo-Δ(4,6) -lithocholyl-Coenzyme A (CoA)] complex are reported. BaiE is a trimer with a twisted α + ß barrel fold with similarity to the Nuclear Transport Factor 2 (NTF2) superfamily. Tyr30, Asp35, and His83 form a catalytic triad that is conserved across this family. Site-directed mutagenesis of BaiE from Clostridium scindens VPI 12708 confirm that these residues are essential for catalysis and also the importance of other conserved residues, Tyr54 and Arg146, which are involved in substrate binding and affect catalytic turnover. Steady-state kinetic studies reveal that the BaiE homologs are able to turn over 3-oxo-Δ(4) -bile acid and CoA-conjugated 3-oxo-Δ(4) -bile acid substrates with comparable efficiency questioning the role of CoA-conjugation in the bile acid metabolism pathway.


Assuntos
Proteínas de Bactérias/química , Ácidos Cólicos/química , Clostridium/enzimologia , Hidroliases/química , Substituição de Aminoácidos , Proteínas de Bactérias/genética , Domínio Catalítico , Ácidos Cólicos/biossíntese , Cristalografia por Raios X , Humanos , Hidroliases/genética , Ligação de Hidrogênio , Hidroxilação , Cinética , Simulação de Acoplamento Molecular , Mutagênese Sítio-Dirigida , Ligação Proteica , Estrutura Secundária de Proteína , Homologia Estrutural de Proteína
4.
Bioconjug Chem ; 26(12): 2554-62, 2015 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-26588668

RESUMO

Post-translational modification catalyzed by phosphopantetheinyl transferases (PPTases) has previously been used to site-specifically label proteins with structurally diverse molecules. PPTase catalysis results in covalent modification of a serine residue in acyl/peptidyl carrier proteins and their surrogate substrates which are typically fused to the N- or C-terminus. To test the utility of PPTases for preparing antibody-drug conjugates (ADCs), we inserted 11 and 12-mer PPTase substrate sequences at 110 constant region loop positions of trastuzumab. Using Sfp-PPTase, 63 sites could be efficiently labeled with an auristatin toxin, resulting in 95 homogeneous ADCs. ADCs labeled in the CH1 domain displayed in general excellent pharmacokinetic profiles and negligible drug loss. A subset of CH2 domain conjugates underwent rapid clearance in mouse pharmacokinetic studies. Rapid clearance correlated with lower thermal stability of the particular antibodies. Independent of conjugation site, almost all ADCs exhibited subnanomolar in vitro cytotoxicity against HER2-positive cell lines. One selected ADC was shown to induce tumor regression in a xenograft model at a single dose of 3 mg/kg, demonstrating that PPTase-mediated conjugation is suitable for the production of highly efficacious and homogeneous ADCs.


Assuntos
Aminobenzoatos/metabolismo , Antineoplásicos/metabolismo , Proteínas de Bactérias/metabolismo , Imunoconjugados/metabolismo , Neoplasias/tratamento farmacológico , Oligopeptídeos/metabolismo , Transferases (Outros Grupos de Fosfato Substituídos)/metabolismo , Trastuzumab/metabolismo , Aminobenzoatos/química , Aminobenzoatos/uso terapêutico , Animais , Antineoplásicos/química , Antineoplásicos/uso terapêutico , Humanos , Imunoconjugados/química , Imunoconjugados/uso terapêutico , Camundongos , Camundongos Nus , Neoplasias/metabolismo , Oligopeptídeos/química , Oligopeptídeos/uso terapêutico , Peptídeos/química , Peptídeos/metabolismo , Especificidade por Substrato , Trastuzumab/química , Trastuzumab/uso terapêutico
5.
Proteins ; 82(2): 216-29, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23836456

RESUMO

Despite significant influence of secondary bile acids on human health and disease, limited structural and biochemical information is available for the key gut microbial enzymes catalyzing its synthesis. Herein, we report apo- and cofactor bound crystal structures of BaiA2, a short chain dehydrogenase/reductase from Clostridium scindens VPI 12708 that represent the first protein structure of this pathway. The structures elucidated the basis of cofactor specificity and mechanism of proton relay. A conformational restriction involving Glu42 located in the cofactor binding site seems crucial in determining cofactor specificity. Limited flexibility of Glu42 results in imminent steric and electrostatic hindrance with 2'-phosphate group of NADP(H). Consistent with crystal structures, steady state kinetic characterization performed with both BaiA2 and BaiA1, a close homolog with 92% sequence identity, revealed specificity constant (kcat /KM ) of NADP(+) at least an order of magnitude lower than NAD(+) . Substitution of Glu42 with Ala improved specificity toward NADP(+) by 10-fold compared to wild type. The cofactor bound structure uncovered a novel nicotinamide-hydroxyl ion (NAD(+) -OH(-) ) adduct contraposing previously reported adducts. The OH(-) of the adduct in BaiA2 is distal to C4 atom of nicotinamide and proximal to 2'-hydroxyl group of the ribose moiety. Moreover, it is located at intermediary distances between terminal functional groups of active site residues Tyr157 (2.7 Å) and Lys161 (4.5 Å). Based on these observations, we propose an involvement of NAD(+) -OH(-) adduct in proton relay instead of hydride transfer as noted for previous adducts.


Assuntos
Proteínas de Bactérias/química , Ácidos e Sais Biliares/biossíntese , Clostridium/enzimologia , Hidroxiesteroide Desidrogenases/química , Apoenzimas/química , Domínio Catalítico , Cristalografia por Raios X , Humanos , Concentração de Íons de Hidrogênio , Cinética , Modelos Moleculares , NAD/química
6.
Chembiochem ; 15(12): 1787-91, 2014 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-25044133

RESUMO

To expand the utility of proteinaceous FRET biosensors, we have developed a dual-labeling approach based on two small bio-orthogonal tags: pyrroline-carboxy-lysine (Pcl) and the S6 peptide. The lack of cross-reactivity between those tags enables site-specific two-color protein conjugation in a one-pot reaction. Moreover, Pcl/S6 dual-tagged proteins can be produced in both bacterial and mammalian expression systems, as demonstrated for Z domain and IgE-Fc, respectively. Both proteins could be efficiently dual-labeled with FRET-compatible fluorescent dyes at neutral pH. In the case of IgE-Fc, the resulting conjugate enabled the monitoring of IgE binding to its high-affinity receptor FcεRI, which is a key event in allergic disease.


Assuntos
Corantes Fluorescentes/química , Lisina/análogos & derivados , Peptídeos/química , Proteínas/química , Coloração e Rotulagem/métodos , Técnicas Biossensoriais , Transferência Ressonante de Energia de Fluorescência , Concentração de Íons de Hidrogênio , Lisina/química , Estrutura Molecular
7.
Proc Natl Acad Sci U S A ; 108(26): 10437-42, 2011 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-21670250

RESUMO

Pyrroline-carboxy-lysine (Pcl) is a demethylated form of pyrrolysine that is generated by the pyrrolysine biosynthetic enzymes when the growth media is supplemented with D-ornithine. Pcl is readily incorporated by the unmodified pyrrolysyl-tRNA/tRNA synthetase pair into proteins expressed in Escherichia coli and in mammalian cells. Here, we describe a broadly applicable conjugation chemistry that is specific for Pcl and orthogonal to all other reactive groups on proteins. The reaction of Pcl with 2-amino-benzaldehyde or 2-amino-acetophenone reagents proceeds to near completion at neutral pH with high efficiency. We illustrate the versatility of the chemistry by conjugating Pcl proteins with poly(ethylene glycol)s, peptides, oligosaccharides, oligonucleotides, fluorescence, and biotin labels and other small molecules. Because Pcl is genetically encoded by TAG codons, this conjugation chemistry enables enhancements of the pharmacology and functionality of proteins through site-specific conjugation.


Assuntos
Lisina/química , Proteínas/química , Pirróis/química , Meios de Cultura , Escherichia coli/genética , Ressonância Magnética Nuclear Biomolecular
8.
Nat Chem Biol ; 7(8): 528-30, 2011 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-21525873

RESUMO

D-ornithine has previously been suggested to enhance the expression of pyrrolysine-containing proteins. We unexpectedly discovered that uptake of D-ornithine results in the insertion of a new amino acid, pyrroline-carboxy-lysine (Pcl) instead of the anticipated pyrrolysine (Pyl). Our feeding and biochemical studies point to specific roles of the poorly understood Pyl biosynthetic enzymes PylC and PylD in converting L-lysine and D-ornithine to Pcl and confirm intermediates in the biosynthesis of Pyl.


Assuntos
Lisina/análogos & derivados , Ornitina/farmacologia , Sequência de Aminoácidos , Escherichia coli , Regulação da Expressão Gênica/fisiologia , Células HEK293 , Humanos , Lisina/biossíntese , Lisina/química , Methanosarcina/genética , Methanosarcina/metabolismo , Estrutura Molecular , Ornitina/química , Ornitina/metabolismo , Plasmídeos , Regiões Promotoras Genéticas
9.
Structure ; 17(2): 303-13, 2009 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-19217401

RESUMO

The crystal structures of two homologous endopeptidases from cyanobacteria Anabaena variabilis and Nostoc punctiforme were determined at 1.05 and 1.60 A resolution, respectively, and contain a bacterial SH3-like domain (SH3b) and a ubiquitous cell-wall-associated NlpC/P60 (or CHAP) cysteine peptidase domain. The NlpC/P60 domain is a primitive, papain-like peptidase in the CA clan of cysteine peptidases with a Cys126/His176/His188 catalytic triad and a conserved catalytic core. We deduced from structure and sequence analysis, and then experimentally, that these two proteins act as gamma-D-glutamyl-L-diamino acid endopeptidases (EC 3.4.22.-). The active site is located near the interface between the SH3b and NlpC/P60 domains, where the SH3b domain may help define substrate specificity, instead of functioning as a targeting domain, so that only muropeptides with an N-terminal L-alanine can bind to the active site.


Assuntos
Endopeptidases/química , Endopeptidases/metabolismo , Peptidoglicano/química , Peptidoglicano/metabolismo , Sequência de Aminoácidos , Anabaena variabilis/química , Anabaena variabilis/enzimologia , Domínio Catalítico , Cisteína Endopeptidases/química , Cisteína Endopeptidases/metabolismo , Cisteína Endopeptidases/fisiologia , Endopeptidases/fisiologia , Modelos Biológicos , Modelos Moleculares , Dados de Sequência Molecular , Nostoc/química , Nostoc/enzimologia , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/metabolismo , Estrutura Terciária de Proteína , Homologia de Sequência de Aminoácidos , Especificidade por Substrato , Domínios de Homologia de src
10.
Oxf Med Case Reports ; 2021(6): omab032, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34158951

RESUMO

We report an unusual case of a missed intraocular foreign body, which was incidentally discovered in the anterior chamber drainage angle of the left eye of a retired masonry worker, some 30 years after the inciting injury. The ocular penetration and intraocular foreign body were missed during initial emergency management, despite the high-velocity mechanism of chiselling granite, which was reported. This case effectively highlights the need for a careful history and examination in high-velocity injuries to the eye (such as those caused by hammering and grinding), a high index of suspicion for intraocular foreign bodies, and considers best practice in managing such presentations.

11.
Pragmat Obs Res ; 12: 93-104, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34408531

RESUMO

INTRODUCTION: Symptoms may persist after the initial phases of COVID-19 infection, a phenomenon termed long COVID. Current knowledge on long COVID has been mostly derived from test-confirmed and hospitalized COVID-19 patients. Data are required on the burden and predictors of long COVID in a broader patient group, which includes both tested and untested COVID-19 patients in primary care. METHODS: This is an observational study using data from Platform C19, a quality improvement program-derived research database linking primary care electronic health record data (EHR) with patient-reported questionnaire information. Participating general practices invited consenting patients aged 18-85 to complete an online questionnaire since 7th August 2020. COVID-19 self-diagnosis, clinician-diagnosis, testing, and the presence and duration of symptoms were assessed via the questionnaire. Patients were considered present with long COVID if they reported symptoms lasting ≥4 weeks. EHR and questionnaire data up till 22nd January 2021 were extracted for analysis. Multivariable regression analyses were conducted comparing demographics, clinical characteristics, and presence of symptoms between patients with long COVID and patients with shorter symptom duration. RESULTS: Long COVID was present in 310/3151 (9.8%) patients with self-diagnosed, clinician-diagnosed, or test-confirmed COVID-19. Only 106/310 (34.2%) long COVID patients had test-confirmed COVID-19. Risk predictors of long COVID were age ≥40 years (adjusted Odds Ratio [AdjOR]=1.49 [1.05-2.17]), female sex (adjOR=1.37 [1.02-1.85]), frailty (adjOR=2.39 [1.29-4.27]), visit to A&E (adjOR=4.28 [2.31-7.78]), and hospital admission for COVID-19 symptoms (adjOR=3.22 [1.77-5.79]). Aches and pain (adjOR=1.70 [1.21-2.39]), appetite loss (adjOR=3.15 [1.78-5.92]), confusion and disorientation (adjOR=2.17 [1.57-2.99]), diarrhea (adjOR=1.4 [1.03-1.89]), and persistent dry cough (adjOR=2.77 [1.94-3.98]) were symptom features statistically more common in long COVID. CONCLUSION: This study reports the factors and symptom features predicting long COVID in a broad primary care population, including both test-confirmed and the previously missed group of COVID-19 patients.

12.
J Biomol NMR ; 46(1): 89-100, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19669620

RESUMO

A large number of amino acids other than the canonical amino acids can now be easily incorporated in vivo into proteins at genetically encoded positions. The technology requires an orthogonal tRNA/aminoacyl-tRNA synthetase pair specific for the unnatural amino acid that is added to the media while a TAG amber or frame shift codon specifies the incorporation site in the protein to be studied. These unnatural amino acids can be isotopically labeled and provide unique opportunities for site-specific labeling of proteins for NMR studies. In this perspective, we discuss these opportunities including new photocaged unnatural amino acids, outline usage of metal chelating and spin-labeled unnatural amino acids and expand the approach to in-cell NMR experiments.


Assuntos
Aminoácidos/química , Marcação por Isótopo/métodos , Ressonância Magnética Nuclear Biomolecular/métodos , Conformação Proteica , Proteínas/química , Isótopos de Carbono/química , Códon de Terminação , Flúor/química , Isótopos de Nitrogênio/química , Células Procarióticas/química , Marcadores de Spin
13.
J Am Chem Soc ; 130(29): 9268-81, 2008 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-18576636

RESUMO

In vivo incorporation of isotopically labeled unnatural amino acids into large proteins drastically reduces the complexity of nuclear magnetic resonance (NMR) spectra. Incorporation is accomplished by coexpressing an orthogonal tRNA/aminoacyl-tRNA synthetase pair specific for the unnatural amino acid added to the media and the protein of interest with a TAG amber codon at the desired incorporation site. To demonstrate the utility of this approach for NMR studies, 2-amino-3-(4-(trifluoromethoxy)phenyl)propanoic acid (OCF 3Phe), (13)C/(15)N-labeled p-methoxyphenylalanine (OMePhe), and (15)N-labeled o-nitrobenzyl-tyrosine (oNBTyr) were incorporated individually into 11 positions around the active site of the 33 kDa thioesterase domain of human fatty acid synthase (FAS-TE). In the process, a novel tRNA synthetase was evolved for OCF 3Phe. Incorporation efficiencies and FAS-TE yields were improved by including an inducible copy of the respective aminoacyl-tRNA synthetase gene on each incorporation plasmid. Using only between 8 and 25 mg of unnatural amino acid, typically 2 mg of FAS-TE, sufficient for one 0.1 mM NMR sample, were produced from 50 mL of Escherichia coli culture grown in rich media. Singly labeled protein samples were then used to study the binding of a tool compound. Chemical shift changes in (1)H-(15)N HSQC, (1)H-(13)C HSQC, and (19)F NMR spectra of the different single site mutants consistently identified the binding site and the effect of ligand binding on conformational exchange of some of the residues. OMePhe or OCF 3Phe mutants of an active site tyrosine inhibited binding; incorporating (15)N-Tyr at this site through UV-cleavage of the nitrobenzyl-photocage from oNBTyr re-established binding. These data suggest not only robust methods for using unnatural amino acids to study large proteins by NMR but also establish a new avenue for the site-specific labeling of proteins at individual residues without altering the protein sequence, a feat that can currently not be accomplished with any other method.


Assuntos
Ressonância Magnética Nuclear Biomolecular/métodos , Fenilalanina/análogos & derivados , Fenilpropionatos/química , Proteínas/análise , Tirosina/análogos & derivados , Aminoacil-tRNA Sintetases/química , Aminoacil-tRNA Sintetases/metabolismo , Isótopos de Carbono , Escherichia coli/genética , Escherichia coli/metabolismo , Ácido Graxo Sintases/química , Ácido Graxo Sintases/genética , Ácido Graxo Sintases/metabolismo , Marcação por Isótopo , Isótopos de Nitrogênio , Fenilpropionatos/metabolismo , Plasmídeos/genética , Engenharia de Proteínas , Estrutura Terciária de Proteína , Proteínas/genética , Proteínas/metabolismo
14.
J Fam Psychol ; 22(4): 586-94, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18729672

RESUMO

Much research has shown that spouses of combat veterans with posttraumatic stress disorder (PTSD) have higher rates of psychological and marital distress than do spouses of veterans without PTSD; however, very few studies have examined potential mechanisms of this increased vulnerability. The current study examined spouses of National Guard soldiers recently returned from deployments in Iraq. In addition to documenting elevated levels of psychological symptoms in these spouses, the authors found that spouses experienced greater symptom severity when they perceived high levels of symptoms in soldiers but the soldiers endorsed low levels of symptoms. Furthermore, spouses' marital satisfaction was negatively linked to soldiers' self-reported symptom severity only when spouses perceived that soldiers had experienced low levels of combat activity while deployed. When spouses perceived high levels of such activity, soldiers' self-reported symptoms had no relationship with spouses' marital satisfaction. These findings highlight the importance of interpersonal perceptions in intimate relationships and are consistent with the notion that uncontrollable attributions for a relative's mental health problems may provide a buffer against relationship distress. (PsycINFO Database Record (c) 2008 APA, all rights reserved).


Assuntos
Transtorno Depressivo Maior/epidemiologia , Transtorno Depressivo Maior/psicologia , Casamento/psicologia , Casamento/estatística & dados numéricos , Militares/psicologia , Militares/estatística & dados numéricos , Satisfação Pessoal , Cônjuges/psicologia , Cônjuges/estatística & dados numéricos , Transtornos de Estresse Pós-Traumáticos/epidemiologia , Transtornos de Estresse Pós-Traumáticos/psicologia , Veteranos/psicologia , Veteranos/estatística & dados numéricos , Adulto , Transtorno Depressivo Maior/diagnóstico , Manual Diagnóstico e Estatístico de Transtornos Mentais , Feminino , Humanos , Relações Interpessoais , Guerra do Iraque 2003-2011 , Masculino , Pessoa de Meia-Idade , Prevalência , Transtornos de Estresse Pós-Traumáticos/diagnóstico , Inquéritos e Questionários
15.
J Pain ; 8(8): 650-6, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17553750

RESUMO

UNLABELLED: The goal of this study was to determine the intra- and interday reliability of pressure pain thresholds (PPT) in the upper extremity and torso of asymptomatic women. Nineteen healthy women (20-39 years) with no underlying musculoskeletal problems had 3 PPT trials performed on 8 different locations in the upper extremity and torso over 4 consecutive days. The test-retest reliability of PPT values was robust and highly consistent over the 4 days. The PPT intraclass correlations (ICC) were highly consistent and repeatable over the 4 days of testing (day 1: ICC = 0.94; day 2: ICC = 0.96; day 3: ICC = 0.97 and day 4: ICC = 0.96). When compared with baseline measurements obtained on day 1, the PPT values were significantly lower (P < .05) on days 2, 3, and 4 at all 8 locations. Although the PPT test-retest reliability is robust and consistent throughout the 4 days, there appears to be a similar overall decline in the magnitude of the absolute PPT response at each of the 8 locations. A specific explanation for this greater overall sensitivity in PPTs at all 8 locations is lacking; however, a centrally mediated alteration in pressure/pain sensation could contribute to the overall trend observed in this study. PERSPECTIVE: PPT measurements of the upper limb and torso will be significantly lower with repeated measures over a short period time. A standardized evaluation grid should be included in baseline so as to accurately evaluate the progression in shoulder rehabilitation in women with shoulder dysfunction.


Assuntos
Medição da Dor , Limiar da Dor/fisiologia , Pressão , Extremidade Superior/fisiologia , Adulto , Estudos de Casos e Controles , Feminino , Humanos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
16.
Biochim Biophys Acta ; 1584(1): 20-30, 2002 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-12213489

RESUMO

The polyamine spermine (N,N'bis[3-aminopropyl]-1,4-butanediamine) activates phosphatidylinositol-4-phosphate 5-kinase (PtdIns(4)P5K) and phosphatidylinositol 4-kinase (PtdIns4K) in vitro. Spermine concentration increases that occur in proliferating cells were approximated in streptolysin O-permeabilized HL60 cells. When phospholipase C was activated by GTPgammaS in the presence of PITPalpha, 0.1-1.2 mM spermine evoked increases in PtdIns(4,5)P(2) contents in a dose-dependent manner to 110-170% of control and concomitantly decreased inositol phosphate formation by 10-50%. Spermine-induced increases in PtdIns(4,5)P(2) content in permeabilized cells also occurred during GTPgammaS stimulation in the absence of PITPalpha, were augmented in the presence of PITPalpha, occurred in unstimulated cells and were additive to PtdIns(4,5)P(2) formation evoked by ARF1, another activator of phosphoinositide kinases. Slowly developing spermine-evoked increases in PtdIns(4,5)P(2) contents occurred in nonpermeabilized cells that were abolished in the presence of a spermine transport inhibitor. Data are consistent with spermine at physiological concentrations evoking a PITPalpha-dependent shift in formation of PtdIns(4,5)P(2) from compartments that contained an active phospholipase C to compartments that were separated from an active PLC and from PtdIns(4,5)P(2) formed by ARF1.


Assuntos
Células HL-60/efeitos dos fármacos , Fosfatidilinositol 4,5-Difosfato/metabolismo , Espermina/farmacologia , Fator 1 de Ribosilação do ADP/farmacologia , Proteínas de Bactérias , Relação Dose-Resposta a Droga , Ativação Enzimática/efeitos dos fármacos , Guanosina 5'-O-(3-Tiotrifosfato) , Células HL-60/metabolismo , Humanos , Fosfatos de Inositol/análise , Fosfatos de Inositol/metabolismo , Fosfatidilinositol 4,5-Difosfato/análise , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Espermina/antagonistas & inibidores , Estreptolisinas , Fatores de Tempo
17.
Protein Sci ; 11(3): 546-57, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11847278

RESUMO

Vpu is an 81-residue accessory protein of HIV-1. Because it is a membrane protein, it presents substantial technical challenges for the characterization of its structure and function, which are of considerable interest because the protein enhances the release of new virus particles from cells infected with HIV-1 and induces the intracellular degradation of the CD4 receptor protein. The Vpu-mediated enhancement of the virus release rate from HIV-1-infected cells is correlated with the expression of an ion channel activity associated with the transmembrane hydrophobic helical domain. Vpu-induced CD4 degradation and, to a lesser extent, enhancement of particle release are both dependent on the phosphorylation of two highly conserved serine residues in the cytoplasmic domain of Vpu. To define the minimal folding units of Vpu and to identify their activities, we prepared three truncated forms of Vpu and compared their structural and functional properties to those of full-length Vpu (residues 2-81). Vpu(2-37) encompasses the N-terminal transmembrane alpha-helix; Vpu(2-51) spans the N-terminal transmembrane helix and the first cytoplasmic alpha-helix; Vpu(28-81) includes the entire cytoplasmic domain containing the two C-terminal amphipathic alpha-helices without the transmembrane helix. Uniformly isotopically labeled samples of the polypeptides derived from Vpu were prepared by expression of fusion proteins in E. coli and were studied in the model membrane environments of lipid micelles by solution NMR spectroscopy and oriented lipid bilayers by solid-state NMR spectroscopy. The assignment of backbone resonances enabled the secondary structure of the constructs corresponding to the transmembrane and the cytoplasmic domains of Vpu to be defined in micelle samples by solution NMR spectroscopy. Solid-state NMR spectra of the polypeptides in oriented lipid bilayers demonstrated that the topology of the domains is retained in the truncated polypeptides. The biological activities of the constructs of Vpu were evaluated. The ion channel activity is confined to the transmembrane alpha-helix. The C-terminal alpha-helices modulate or promote the oligomerization of Vpu in the membrane and stabilize the conductive state of the channel, in addition to their involvement in CD4 degradation.


Assuntos
HIV-1/fisiologia , Proteínas Virais Reguladoras e Acessórias/fisiologia , Substituição de Aminoácidos , Antígenos CD4 , Clonagem Molecular , HIV-1/genética , Proteínas do Vírus da Imunodeficiência Humana , Canais Iônicos/fisiologia , Espectroscopia de Ressonância Magnética , Metionina , Dobramento de Proteína , Estrutura Secundária de Proteína , Radioisótopos , Proteínas Virais Reguladoras e Acessórias/química , Proteínas Virais Reguladoras e Acessórias/genética , Proteínas Virais Reguladoras e Acessórias/isolamento & purificação
18.
J Magn Reson ; 171(2): 258-69, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15546752

RESUMO

Residual dipolar couplings are important as angular constraints for the structure determination of membrane proteins in micelles. Strained polyacrylamide gels are one of the few available mechanisms available for inducing the requisite weak alignment for these samples. However, their use is frequently limited by the ability to incorporate proteins and buffer solutions into the gel matrix. The implementation of several methods of incorporating membrane proteins into gels are described. Conditions for copolymerizing the protein in the absence of a change in pH are detailed. Electrophoresis is also shown to be a useful method to incorporate proteins. Weak alignment of the protein-micelle complex in the gel matrix is subsequently achieved using either vertical or radial compression. The magnitude of alignment can be controlled by altering the gel concentration, the acrylamide/bisacrylamide ratio, and the compression ratio. The alignment tensor can be altered relative to uncharged polyacrylamide gels by copolymerizing samples with acrylamide/acrylic acid to incorporate negative charges in the strained polyacrylamide gel to provide an alternate orientation.


Assuntos
Proteínas do Capsídeo/química , Proteínas de Membrana/química , Ressonância Magnética Nuclear Biomolecular/métodos , Resinas Acrílicas , Eletroforese em Gel de Poliacrilamida , Micelas , Isótopos de Nitrogênio
19.
Springerplus ; 3: 150, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24790808

RESUMO

PURPOSE: The main objective of this prospective study was to obtain a better understanding of the body composition and vital sign measures of cancers survivors (CS) when compared to regular (R) patients. METHODS: A total of 9,315 female patients were evaluated: 476 CS and 8,839 R patients. Kinesiologists worked side by side with the medical/oncology team to collect a number of base-line measurements on body composition, resting heart rate, and blood pressure as part of the standard intake evaluation during the female patients' annual checkup. RESULTS: CS were more likely to have a higher BMI (P = 0.001) and a larger waist circumference (P = 0.001) than R patients. CS were also shown to have higher blood pressure values: diastolic pressure of 76.9 mmHg ± 10.5 VS 75.5 mmHg ± 9.9, (P = 0.01) and systolic pressure of 129.8 mmHg ± 17.2 VS 126.7 mmHg ±17.4 (P = 0.001) compared to R patients, respectively. Regression analysis looking at the relationship between mean arterial pressure and waist circumference did not show any difference between the two groups (CS vs R). CONCLUSION: CS who had a higher BMI, a larger waist circumference and higher blood pressure levels, are probably at greater risk for developing cardiovascular disease, diabetes, various musculoskeletal problems as well as an increased risk for various forms of cancers including reoccurrence of previously treated cancer when compared to R patients. Changes in body composition should be considered by the medical team when looking at preventative healthcare strategies for their CS patients.

20.
ACS Macro Lett ; 1(1): 80-83, 2012 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-35578458

RESUMO

Stimuli-responsive materials are desired for a wide range of applications. Here, we report the design and fabrication of all-organic, stimuli-responsive polymer composites using electrospun nanofibers as the filler. The incorporation of 4 wt % of filler into the polymer matrix increased the tensile storage modulus by 2 orders of magnitude. Upon exposure to water, the filler fibers plasticize and no longer provide mechanical reinforcement. The tensile storage modulus subsequently diminishes 2 orders of magnitude to the value of the neat matrix polymer.

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