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1.
BMC Public Health ; 24(1): 2492, 2024 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-39272039

RESUMO

BACKGROUND: Deep-rooted racial residential segregation and housing discrimination have given rise to housing disparities among low-income Black young adults in the US. Most studies have focused on single dimensions of housing instability, and thus provide a partial view of how Black young adults experience multiple, and perhaps overlapping, experiences of housing instability including homelessness, frequent moves, unaffordability, or evictions. We aimed to illuminate the multiple forms of housing instability that Black young adults contend with and examine relationships between housing instability and mental health outcomes. METHODS: Using baseline data from the Black Economic Equity Movement (BEEM) guaranteed income trial with 300 urban low-income Black young adults (aged 18-24), we conducted a three-stage latent class analysis using nine housing instability indicators. We identified distinct patterns by using fit indices and theory to determine the optimal number of latent classes. We then used multinomial logistic regression to identify subpopulations disproportionately represented within unstable housing patterns. Finally, we estimated associations between housing experience patterns and mental health outcomes: depression, anxiety, and hope. RESULTS: We found high prevalence of housing instability with 27.3% of participants reporting experiences of homelessness in the prior year and 39.0% of participants reporting multiple measures of housing instability. We found the 4-class solution to be the best fitting model for the data based on fit indices and theory. Latent classes were characterized as four housing experience patterns: 1) more stably housed, 2) unaffordable and overcrowded housing, 3) mainly unhoused, and 4) multiple dimensions of housing instability. Those experiencing unaffordable and overcrowded housing and being mainly unhoused were more than four times as likely to have symptoms of depression (Unaffordable: aOR = 4.57, 95% CI: 1.64, 12.72; Unhoused: aOR = 4.67, 95% CI:1.18, 18.48) and more than twice as likely to report anxiety (Unaffordable: aOR = 2.28, 95% CI: 1.03, 5.04; Unhoused: aOR = 3.36, 95% CI: 1.12, 10.05) compared to the more stably housed pattern. We found that hope scores were similarly high across patterns. CONCLUSIONS: High prevalence of housing instability and mental health challenges among low-income Black young adults demands tailored interventions to reduce instability, given widening racial disparities and implications for future well-being into adulthood.


Assuntos
Negro ou Afro-Americano , Pessoas Mal Alojadas , Saúde Mental , Pobreza , População Urbana , Adolescente , Feminino , Humanos , Masculino , Adulto Jovem , Negro ou Afro-Americano/estatística & dados numéricos , Negro ou Afro-Americano/psicologia , California/epidemiologia , Habitação/estatística & dados numéricos , Pessoas Mal Alojadas/estatística & dados numéricos , Pessoas Mal Alojadas/psicologia , Saúde Mental/estatística & dados numéricos , População Urbana/estatística & dados numéricos
2.
Chembiochem ; 23(20): e202200390, 2022 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-35950614

RESUMO

Accurate formation of antibody-antigen complexes has been relied on in both, multitudes of scientific projects and ample therapeutic and diagnostic applications. Mass spectrometrically determined dissociation behavior of immune complexes with the anti-HpTGEKP antibody revealed that the ten most frequently occurring phospho-hexapeptide linker sequences from C2H2 zinc finger proteins could be divided into two classes: orthodox binders, where strong noncovalent interactions developed as anticipated, and unorthodox binders with deviating structures and weaker binding. Phosphorylation of threonine was compulsory for antibody binding in an orthodox manner. Gas phase dissociation energy determinations of seven C2H2 zinc finger protein linker phospho-hexapeptides with orthodox binding properties revealed a bipolar binding motif of the antibody paratope. Epitope peptides, which in addition to the negatively charged phospho-threonine residue were C-terminally flanked by positively charged residues provided stronger binding, i. e. dissociation was endothermic, than peptides with acidic amino acid residues at these positions, for which dissociation was exothermic.


Assuntos
Anticorpos Monoclonais , Complexo Antígeno-Anticorpo , Dedos de Zinco , Espectrometria de Massas , Epitopos/química , Peptídeos/química , Treonina , Aminoácidos Acídicos
3.
J Biol Chem ; 295(44): 14987-14997, 2020 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-32848020

RESUMO

Rapid diagnostic tests are first-line assays for diagnosing infectious diseases, such as malaria. To minimize false positive and false negative test results in population-screening assays, high-quality reagents and well-characterized antigens and antibodies are needed. An important property of antigen-antibody binding is recognition specificity, which best can be estimated by mapping an antibody's epitope on the respective antigen. We have cloned a malarial antigen-containing fusion protein, MBP-pfMSP119, in Escherichia coli, which then was structurally and functionally characterized before and after high pressure-assisted enzymatic digestion. We then used our previously developed method, intact transition epitope mapping-targeted high-energy rupture of extracted epitopes (ITEM-THREE), to map the area on the MBP-pfMSP119 antigen surface that is recognized by the anti-pfMSP119 antibody G17.12. We identified three epitope-carrying peptides, 386GRNISQHQCVKKQCPQNSGCFRHLDE411, 386GRNISQHQCVKKQCPQNSGCFRHLDEREE414, and 415CKCLLNYKQE424, from the GluC-derived peptide mixture. These peptides belong to an assembled (conformational) epitope on the MBP-pfMSP119 antigen whose identification was substantiated by positive and negative control experiments. In conclusion, our data help to establish a workflow to obtain high-quality control data for diagnostic assays, including the use of ITEM-THREE as a powerful analytical tool. Data are available via ProteomeXchange: PXD019717.


Assuntos
Anticorpos Monoclonais/imunologia , Antígenos de Protozoários/imunologia , Epitopos/imunologia , Malária Falciparum/imunologia , Proteína 1 de Superfície de Merozoito/imunologia , Sequência de Aminoácidos , Animais , Complexo Antígeno-Anticorpo/imunologia , Western Blotting , Eletroforese em Gel de Poliacrilamida/métodos , Mapeamento de Epitopos/métodos , Espectrometria de Massas por Ionização por Electrospray/métodos
4.
Mol Cell Proteomics ; 18(8): 1543-1555, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31147491

RESUMO

Epitope mapping, which is the identification of antigenic determinants, is essential for the design of novel antibody-based therapeutics and diagnostic tools. ITEM-THREE is a mass spectrometry-based epitope mapping method that can identify epitopes on antigens upon generating an immune complex in electrospray-compatible solutions by adding an antibody of interest to a mixture of peptides from which at least one holds the antibody's epitope. This mixture is nano-electrosprayed without purification. Identification of the epitope peptide is performed within a mass spectrometer that provides an ion mobility cell sandwiched in-between two collision cells and where this ion manipulation setup is flanked by a quadrupole mass analyzer on one side and a time-of-flight mass analyzer on the other side. In a stepwise fashion, immune-complex ions are separated from unbound peptide ions and dissociated to release epitope peptide ions. Immune complex-released peptide ions are separated from antibody ions and fragmented by collision induced dissociation. Epitope-containing peptide fragment ions are recorded, and mass lists are submitted to unsupervised data base search thereby retrieving both, the amino acid sequence of the epitope peptide and the originating antigen. ITEM-THREE was developed with antiTRIM21 and antiRA33 antibodies for which the epitopes were known, subjecting them to mixtures of synthetic peptides of which one contained the respective epitope. ITEM-THREE was then successfully tested with an enzymatic digest of His-tagged recombinant human ß-actin and an antiHis-tag antibody, as well as with an enzymatic digest of recombinant human TNFα and an antiTNFα antibody whose epitope was previously unknown.


Assuntos
Mapeamento de Epitopos/métodos , Epitopos/imunologia , Actinas/imunologia , Anticorpos/imunologia , Complexo Antígeno-Anticorpo , Humanos , Peptídeos/imunologia , Ribonucleoproteínas/imunologia , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas em Tandem , Fator de Necrose Tumoral alfa/química , Fator de Necrose Tumoral alfa/imunologia
5.
Int J Mol Sci ; 22(19)2021 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-34638522

RESUMO

We investigated the influence of a solvent's composition on the stability of desorbed and multiply charged RNAse S ions by analyzing the non-covalent complex's gas-phase dissociation processes. RNAse S was dissolved in electrospray ionization-compatible buffers with either increasing organic co-solvent content or different pHs. The direct transition of all the ions and the evaporation of the solvent from all the in-solution components of RNAse S under the respective in-solution conditions by electrospray ionization was followed by a collision-induced dissociation of the surviving non-covalent RNAse S complex ions. Both types of changes of solvent conditions yielded in mass spectrometrically observable differences of the in-solution complexation equilibria. Through quantitative analysis of the dissociation products, i.e., from normalized ion abundances of RNAse S, S-protein, and S-peptide, the apparent kinetic and apparent thermodynamic gas-phase complex properties were deduced. From the experimental data, it is concluded that the stability of RNAse S in the gas phase is independent of its in-solution equilibrium but is sensitive to the complexes' gas-phase charge states. Bio-computational in-silico studies showed that after desolvation and ionization by electrospray, the remaining binding forces kept the S-peptide and S-protein together in the gas phase predominantly by polar interactions, which indirectly stabilized the in-bulk solution predominating non-polar intermolecular interactions. As polar interactions are sensitive to in-solution protonation, bio-computational results provide an explanation of quantitative experimental data with single amino acid residue resolution.


Assuntos
Biologia Computacional/métodos , Ribonucleases/química , Solventes/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Animais , Fenômenos Biofísicos/fisiologia , Bovinos , Simulação por Computador , Ribonucleases/análise , Termodinâmica
6.
Molecules ; 25(20)2020 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-33080923

RESUMO

Electrospray mass spectrometry is applied to determine apparent binding energies and quasi equilibrium dissociation constants of immune complex dissociation reactions in the gas phase. Myoglobin, a natural protein-ligand complex, has been used to develop the procedure which starts from determining mean charge states and normalized and averaged ion intensities. The apparent dissociation constant KD m0g#= 3.60 × 10-12 for the gas phase heme dissociation process was calculated from the mass spectrometry data and by subsequent extrapolation to room temperature to mimic collision conditions for neutral and resting myoglobin. Similarly, for RNAse S dissociation at room temperature a KD m0g#= 4.03 × 10-12 was determined. The protocol was tested with two immune complexes consisting of epitope peptides and monoclonal antibodies. For the epitope peptide dissociation reaction of the FLAG peptide from the antiFLAG antibody complex an apparent gas phase dissociation constant KD m0g#= 4.04 × 10-12 was calculated. Likewise, an apparent KD m0g#= 4.58 × 10-12 was calculated for the troponin I epitope peptide-antiTroponin I antibody immune complex dissociation. Electrospray mass spectrometry is a rapid method, which requires small sample amounts for either identification of protein-bound ligands or for determination of the apparent gas phase protein-ligand complex binding strengths.


Assuntos
Complexo Antígeno-Anticorpo/química , Epitopos/química , Complexos Multiproteicos/química , Mioglobina/química , Anticorpos/química , Anticorpos/imunologia , Complexo Antígeno-Anticorpo/genética , Complexo Antígeno-Anticorpo/imunologia , Epitopos/imunologia , Heme/química , Heme/imunologia , Humanos , Imunoconjugados/química , Imunoconjugados/imunologia , Ligantes , Complexos Multiproteicos/genética , Complexos Multiproteicos/imunologia , Mioglobina/genética , Mioglobina/imunologia , Oligopeptídeos/química , Oligopeptídeos/genética , Oligopeptídeos/imunologia , Peptídeos/química , Peptídeos/imunologia , Ribonucleases/química , Ribonucleases/imunologia , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
7.
Diabet Med ; 36(7): 862-867, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30972793

RESUMO

AIM: To evaluate the performance of the current, pre-production version of a novel home oral glucose tolerance test (Home OGTT) device when administered by trained research nurses, compared with a reference laboratory glucose analyser and a second laboratory analyser, incorporating a sample processing delay to simulate normal practice. METHODS: One hundred women (aged 19-48 years), with and without known glucose intolerance were recruited. Following an overnight fast, participants attended for a 75-g OGTT. A fasting capillary sample was applied to the Home OGTT device with a corresponding venous sample collected and measured immediately on the reference YSI 2300 stat plus analyser, and following a 1-h delay on the Randox Daytona Plus analyser. The sampling process was repeated 2 h after the oral glucose load. RESULTS: Some 97% of tested devices gave complete data for analysis. Good agreement was observed between the reference glucose analyser and the Home OGTT device, with the Home OGTT device displaying a small negative bias (-0.18 mmol/l, -1.75 to 1.39 mmol/mol; -1.0%, -26.4% to 24.5%; absolute and relative mean, 95% limits of agreement). When classified as normal glucose tolerant or glucose intolerant, the Home OGTT device showed 100% and 90% sensitivity, and 99% and 99% specificity using fasting plasma glucose and 2-h glucose respectively. Similar sensitivity (100% and 100%) and specificity (96% and 99%) for fasting plasma glucose and 2-h glucose were observed using the secondary analyser. CONCLUSIONS: The novel Home OGTT device was reliable and easy to use and showed excellent agreement with two separate laboratory analysers. The Home OGTT offers potential as an effective alternative for clinic-based OGTT testing.


Assuntos
Glicemia/metabolismo , Jejum/sangue , Intolerância à Glucose/sangue , Teste de Tolerância a Glucose/instrumentação , Adulto , Feminino , Humanos , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Autoadministração , Adulto Jovem
8.
Anal Bioanal Chem ; 409(28): 6549-6558, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28900708

RESUMO

We have developed a method to determine apparent activation energies of dissociation for ionized protein-protein complexes in the gas phase using electrospray ionization mass spectrometry following the Rice-Ramsperger-Kassel-Marcus quasi-equilibrium theory. Protein-protein complexes were formed in solution, transferred into the gas phase, and separated from excess free protein by ion mobility filtering. Afterwards, complex disassembly was initiated by collision-induced dissociation with step-wise increasing energies. Relative intensities of ion signals were used to calculate apparent activation energies of dissociation in the gas phase by applying linear free energy relations. The method was developed using streptavidin tetramers. Experimentally determined apparent gas-phase activation energies for dissociation ([Formula: see text]) of complexes consisting of Fc parts from immunoglobulins (IgG-Fc) and three closely related protein G' variants (IgG-Fc•protein G'e, IgG-Fc•protein G'f, and IgG-Fc•protein G'g) show the same order of stabilities as can be inferred from their in-solution binding constants. Differences in stabilities between the protein-protein complexes correspond to single amino acid residue exchanges in the IgG-binding regions of the protein G' variants. Graphical abstract Electrospray mass spectrometry and collision-induced dissociation delivers apparent activation energies and supramolecular bond force constants of protein-protein complexes in the gas phase.


Assuntos
Fragmentos Fc das Imunoglobulinas/metabolismo , Imunoglobulina G/metabolismo , Espectrometria de Massas por Ionização por Electrospray/métodos , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Humanos , Fragmentos Fc das Imunoglobulinas/química , Imunoglobulina G/química , Simulação de Acoplamento Molecular , Ligação Proteica , Domínios Proteicos , Isoformas de Proteínas/química , Isoformas de Proteínas/metabolismo , Multimerização Proteica , Termodinâmica
9.
Eur J Mass Spectrom (Chichester) ; 23(6): 445-459, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29183193

RESUMO

Proteins are essential for almost all physiological processes of life. They serve a myriad of functions which are as varied as their unique amino acid sequences and their corresponding three-dimensional structures. To fulfill their tasks, most proteins depend on stable physical associations, in the form of protein complexes that evolved between themselves and other proteins. In solution (condensed phase), proteins and/or protein complexes are in constant energy exchange with the surrounding solvent. Albeit methods to describe in-solution thermodynamic properties of proteins and of protein complexes are well established and broadly applied, they do not provide a broad enough access to life-science experimentalists to study all their proteins' properties at leisure. This leaves great desire to add novel methods to the analytical biochemist's toolbox. The development of electrospray ionization created the opportunity to characterize protein higher order structures and protein complexes rather elegantly by simultaneously lessening the need of sophisticated sample preparation steps. Electrospray mass spectrometry enabled us to translate proteins and protein complexes very efficiently into the gas phase under mild conditions, retaining both, intact protein complexes, and gross protein structures upon phase transition. Moreover, in the environment of the mass spectrometer (gas phase, in vacuo), analyte molecules are free of interactions with surrounding solvent molecules and, therefore, the energy of inter- and intramolecular forces can be studied independently from interference of the solvating environment. Provided that gas phase methods can give information which is relevant for understanding in-solution processes, gas phase protein structure studies and/or investigations on the characterization of protein complexes has rapidly gained more and more attention from the bioanalytical scientific community. Recent reports have shown that electrospray mass spectrometry provides direct access to six prime protein complex properties: stabilities, compositions, binding surfaces (epitopes), disassembly processes, stoichiometries, and thermodynamic parameters.


Assuntos
Proteínas/química , Animais , Humanos , Transição de Fase , Ligação Proteica , Conformação Proteica , Espectrometria de Massas por Ionização por Electrospray
10.
J Fish Biol ; 85(2): 292-306, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24890734

RESUMO

The genus Salmo was employed as a model to study introgression of genes between species due to secondary contacts. Seven microsatellite loci, the LDH-C1* locus and the 5S ribosomal DNA were studied. Results showed the mutually enhanced introgression of allochthonous genomes into southern European salmonids. This phenomenon appears to go beyond a simple consequence of the altered behaviour of domestic individuals. Invasions of autochthonous genomes by allochthonous genes would be enhanced by human activities such as stock transfers, which would simultaneously promote allochthonous and allospecific (from other species) introgressions in a synergistic process in Atlantic salmon Salmo salar and brown trout Salmo trutta. As a minor result, the data do not support the value of the microsatellite locus SsaD486 as a species-specific marker.


Assuntos
Genética Populacional , Hibridização Genética , Repetições de Microssatélites , RNA Ribossômico 5S/genética , Salmonidae/genética , Animais , Europa (Continente) , Variação Genética , Genoma , Especificidade da Espécie
11.
Heredity (Edinb) ; 111(1): 34-43, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23512011

RESUMO

Glacial and postglacial processes are known to be important determinants of contemporary population structuring for many species. In Europe, refugia in the Italian, Balkan and Iberian peninsulas are believed to be the main sources of species colonising northern Europe after the glacial retreat; however, there is increasing evidence of small, cryptic refugia existing north of these for many cold-tolerant species. This study examined the glacial history of Atlantic salmon in western Europe using two independent classes of molecular markers, microsatellites (nuclear) and mitochondrial DNA variation. Alongside the well-documented refuge in the Iberian Peninsula, evidence for a cryptic refuge in northwest France is also presented. Critically, methods utilised to estimate divergence times between the refugia indicated that salmon in these two regions had diverged a long time before the last glacial maximum; coalescence analysis (as implemented in the program IMa2) estimated divergence times at around 60 000 years before present. Through the examination of haplotype frequencies, previously glaciated areas of northwest Europe, that is, Britain and Ireland, appear to have been colonised from salmon expanding out of both refugia, with the southwest of England being the primary contact zone and exhibiting the highest genetic diversity.


Assuntos
Evolução Molecular , Salmo salar/genética , Animais , DNA Mitocondrial/genética , Europa (Continente) , Marcadores Genéticos , Genética Populacional , Haplótipos , Repetições de Microssatélites , Filogenia , Polimorfismo de Fragmento de Restrição , Salmo salar/classificação , Salmo salar/crescimento & desenvolvimento
12.
Eur J Mass Spectrom (Chichester) ; 29(5-6): 303-312, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37259551

RESUMO

Pepsin, because of its optimal activity at low acidic pH, has gained importance in mass spectrometric proteome research as a readily available and easy-to-handle protease. Pepsin has also been study object of protein higher-order structure analyses, but questions about how to best investigate pepsin in-solution conformers still remain. We first determined dependencies of pepsin ion charge structures on solvent pH which indicated the in-solution existence of (a) natively folded pepsin (N) which by nanoESI-MS analysis gave rise to a narrow charge state distribution with an 11-fold protonated most intense ion signal, (b) unfolded pepsin (U) with a rather broad ion charge state distribution whose highest ion signal carried 25 protons, and (c) a compactly folded pepsin conformer (C) with a narrow charge structure and a 12-fold protonated ion signal in the center of its charge state envelope. Because pepsin is a protease, unfolded pepsin became its own substrate in solution at pH 6.6 since at this pH some portion of pepsin maintained a compact/native fold which displayed enzymatic activity. Subsequent mass spectrometric ITEM-TWO analyses of pepstatin A - pepsin complex dissociation reactions in the gas phase confirmed a very strong binding of pepstatin A by natively folded pepsin (N). ITEM-TWO further revealed the existence of two compactly folded in-solution pepsin conformers (Ca and Cb) which also were able to bind pepstatin A. Binding strengths of the respective compactly folded pepsin conformer-containing complexes could be determined and apparent gas phase complex dissociation constants and reaction enthalpies differentiated these from each other and from the pepstatin A - pepsin complex which had been formed from natively folded pepsin. Thus, ITEM-TWO turned out to be well suited to pinpoint in-solution pepsin conformers by interrogating quantitative traits of pepstatin A - pepsin complexes in the gas phase.


Assuntos
Pepsina A , Espectrometria de Massas por Ionização por Electrospray , Pepsina A/química , Pepsina A/metabolismo , Pepstatinas/química , Espectrometria de Massas por Ionização por Electrospray/métodos
13.
Orphanet J Rare Dis ; 17(1): 179, 2022 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-35505348

RESUMO

BACKGROUND: Ceroid lipofuscinoses neuronal 6 (CLN6) disease belongs to the neuronal ceroid lipofuscinoses (NCLs), complex and genetically heterogeneous disorders with wide geographical and phenotypic variation. The first clinical signs usually appear between 18 months and 8 years, but examples of later-onset have also been reported. Common manifestations include ataxia, seizures, vision impairment, and developmental regression. Because these are shared by other neurological diseases, identification of CLN6 genetic variants is imperative for early diagnosis. RESULTS: We present one of the largest cohorts to date of genetically diagnosed CLN6 patients screened at a single center. In total 97 subjects, originating from 20 countries were screened between 2010 and 2020. They comprised 86 late-infantile, eight juvenile, and three adult-onset cases (two patients with Kufs disease type A, and one with teenage progressive myoclonic epilepsy). The male to female ratio was 1.06: 1.00. The age at referral was between six months and 33 years. The time from disease onset to referral ranged from less than 1 month to 8.3 years. The clinical phenotype consisted of a combination of symptoms, as reported before. We characterized a total of 45 distinct variants defining 45 distinct genotypes. Twenty-four were novel variants, some with distinct geographic associations. Remarkably, c.257A > G (p.H86R) was present in five out of 23 unrelated Egyptian individuals but in no patients from other countries. The most common genotype was homozygosity for the c.794_796del in-frame deletion. It was present in about one-third of CLN6 patients (28 unrelated cases, and 2 familial cases), all with late-infantile onset. Variants with a high likelihood of causing loss of CLN6 function were found in 21% of cases and made up 33% of all distinct variants. Forty-four percent of variants were classified as pathogenic or likely pathogenic. CONCLUSIONS: Our study significantly expands the number of published clinical cases and the mutational spectrum of disease-associated CLN6 variants, especially for the Middle Eastern and North African regions. We confirm previous observations regarding the most prevalent symptoms and recommend including CLN6 in the genetic diagnosis of patients presenting with early-onset abnormalities of the nervous system, musculoskeletal system, and eye.


Assuntos
Epilepsias Mioclônicas Progressivas , Lipofuscinoses Ceroides Neuronais , Adolescente , Feminino , Humanos , Masculino , Proteínas de Membrana/genética , Mutação/genética , Lipofuscinoses Ceroides Neuronais/genética
14.
AIDS Care ; 22(10): 1245-51, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20640953

RESUMO

Understanding the definition and meaning of the word "sex" has implications for sexual medicine, HIV/AIDS research, and clinical practices. Previous studies have reported variations in the definition of having "had sex" and the necessity of using behaviorally specific terminology when taking sexual histories and assessing sexual risk. The purpose of the current study is to assess gay men's definitions of what constitutes having "had sex." Two international convenience samples are compared: a UK sample of 180 self-identified gay men ranging from 18 to 56 years of age (M=36 years; SD=8.29) and a US sample of 190 self-identified gay men ranging 18-74 years of age (M=33.9 years; SD=12.49). Both groups were asked to indicate whether each of a list of sexual behaviors was considered having "had sex." Almost all participants (~95%) believed that penile-anal intercourse constituted having "had sex." US and UK gay men differed in defining the following as having "had sex": giving oral-genital stimulation (US 71.6%, UK 84.9%, P=0.002); giving (G) and receiving (R) manual-anal stimulation (G: US 53.4%, UK 70.9%, P=0.001; R: US 53.7%, UK 71.2%, P=0.001); giving and receiving oral-anal stimulation (G: US 61.2%, UK 78.4%, P<0.001; R: US 59.3%, UK 78.1, P<0.001); and giving and receiving sex-toy stimulation (G: US 55%, UK 77.1%, P<0.001; R: US 56.1%, UK 77.7%, P<0.001). It is important to note that regardless of country there was not overall consensus on which behaviors constituted having "had sex." These findings reinforce the need for behavioral specificity in documenting sexual histories and assessing sexual risk. Further, researchers and clinicians should exercise caution by not assuming that their own definitions of the term "sex" is shared by their gay male participants or patients.


Assuntos
Conhecimentos, Atitudes e Prática em Saúde , Homossexualidade Masculina/psicologia , Comportamento Sexual/classificação , Percepção Social , Adolescente , Adulto , Idoso , Humanos , Relações Interpessoais , Masculino , Pessoa de Meia-Idade , Comportamento Sexual/psicologia , Inquéritos e Questionários , Terminologia como Assunto , Reino Unido , Estados Unidos , Adulto Jovem
15.
J Proteomics ; 212: 103572, 2020 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-31683061

RESUMO

We have developed an electrospray mass spectrometry method which is capable to determine antibody affinity in a gas phase experiment. A solution with the immune complex is electrosprayed and multiply charged ions are translated into the gas phase. Then, the intact immune-complex ions are separated from unbound peptide ions. Increasing the voltage difference in a collision cell results in collision induced dissociation of the immune-complex by which bound peptide ions are released. When analyzing a peptide mixture, measuring the mass of the complex-released peptide ions identifies which of the peptides contains the epitope. A step-wise increase in the collision cell voltage difference changes the intensity ratios of the surviving immune complex ions, the released peptide ions, and the antibody ions. From all the ions´ normalized intensity ratios are deduced the thermodynamic quasi equilibrium dissociation constants (KDm0g#) from which are calculated the apparent gas phase Gibbs energies of activation over temperature (ΔGm0g#T). The order of the apparent gas phase dissociation constants of four antibody - epitope peptide pairs matched well with those obtained from in-solution measurements. The determined gas phase values for antibody affinities are independent from the source of the investigated peptides and from the applied instrument. Data are available via ProteomeXchange with identifier PXD016024. SIGNIFICANCE: ITEM - TWO enables rapid epitope mapping and determination of apparent dissociation energies of immune complexes with minimal in-solution handling. Mixing of antibody and antigen peptide solutions initiates immune complex formation in solution. Epitope binding strengths are determined in the gas phase after electrospraying the antibody / antigen peptide mixtures and mass spectrometric analysis of immune complexes under different collision induced dissociation conditions. Since the order of binding strengths in the gas phase is the same as that in solution, ITEM - TWO characterizes two most important antibody properties, specificity and affinity.


Assuntos
Anticorpos/imunologia , Complexo Antígeno-Anticorpo/imunologia , Mapeamento de Epitopos/métodos , Epitopos/imunologia , Fragmentos de Peptídeos/imunologia , Ribonucleoproteínas/imunologia , Termodinâmica , Anticorpos/química , Complexo Antígeno-Anticorpo/química , Complexo Antígeno-Anticorpo/metabolismo , Epitopos/química , Humanos , Fragmentos de Peptídeos/química , Ribonucleoproteínas/metabolismo , Espectrometria de Massas por Ionização por Electrospray/instrumentação , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos
16.
J Fish Biol ; 74(5): 1136-42, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20735624

RESUMO

Complete sequencing of the mtDNA control region (CR) from five specimens of brown trout Salmo trutta from the Amu Darya River identified two novel haplotypes belonging to the Danubian lineage. This finding supports the long-standing hypothesis that brown trout in the Aral Sea represent a distinct genetic stock and also illustrates the benefits that complete sequencing of the CR can provide for elucidating phylogeographic relationships.


Assuntos
DNA Mitocondrial/genética , Filogenia , Truta/genética , Animais , Genética Populacional , Haplótipos , Análise de Sequência de DNA , Truta/classificação
17.
J Nematol ; 39(2): 176-89, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19259487

RESUMO

Factorial treatments of entomopathogenic nematodes (EPN) and composted, manure mulches were evaluated for two years in a central Florida citrus orchard to study the post-application biology of EPN used to manage the root weevil, Diaprepes abbreviatus. Mulch treatments were applied once each year to study the effects of altering the community of EPN competitors (free-living bactivorous nematodes) and antagonists (nematophagous fungi (NF), predaceous nematodes and some microarthro-pods). EPN were augmented once with Steinernema riobrave in 2004 and twice in 2005. Adding EPN to soil affected the prevalence of organisms at several trophic levels, but the effects were often ephemeral and sometimes inconsistent. EPN augmentation always increased the mortality of sentinel weevil larvae, the prevalence of free-living nematodes in sentinel cadavers and the prevalence of trapping NF. Subsequent to the insecticidal effects of EPN augmentation in 2004, but not 2005, EPN became temporarily less prevalent, and fewer sentinel weevil larvae died in EPN-augmented compared to non-augmented plots. Manure mulch had variable effects on endoparasitic NF, but consistently decreased the prevalence of trapping NF and increased the prevalence of EPN and the sentinel mortality. Both temporal and spatial abundance of NF were inversely related to the prevalence of Steinernema diaprepesi, whereas Heterorhabditis zealandica prevalence was positively correlated with NF over time. The number of weevil larvae killed by EPN was likely greatest in 2005, due in part to non-target effects of augmentation on the endemic EPN community in 2004 that occurred during a period of peak weevil recruitment into the soil.

18.
J Am Soc Mass Spectrom ; 28(8): 1612-1622, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28616748

RESUMO

Intact transition epitope mapping (ITEM) enables rapid and accurate determination of protein antigen-derived epitopes by either epitope extraction or epitope excision. Upon formation of the antigen peptide-containing immune complex in solution, the entire mixture is electrosprayed to translate all constituents as protonated ions into the gas phase. There, ions from antibody-peptide complexes are separated from unbound peptide ions according to their masses, charges, and shapes either by ion mobility drift or by quadrupole ion filtering. Subsequently, immune complexes are dissociated by collision induced fragmentation and the ion signals of the "complex-released peptides," which in effect are the epitope peptides, are recorded in the time-of-flight analyzer of the mass spectrometer. Mixing of an antibody solution with a solution in which antigens or antigen-derived peptides are dissolved is, together with antigen proteolysis, the only required in-solution handling step. Simplicity of sample handling and speed of analysis together with very low sample consumption makes ITEM faster and easier to perform than other experimental epitope mapping methods. Graphical Abstract ᅟ.


Assuntos
Mapeamento de Epitopos/métodos , Espectrometria de Massas por Ionização por Electrospray/métodos , Sequência de Aminoácidos , Animais , Humanos , Imunoglobulina G/química , Espectrometria de Mobilidade Iônica/métodos , Camundongos , Peptídeos/química , Proteólise , Espectrometria de Massas em Tandem/métodos
19.
Per Med ; 12(4): 319-325, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29771653

RESUMO

AIM: The purpose of this study was to pilot a multisite, proof-of-concept model where community pharmacists could engage patients and physicians to provide pharmacogenetic (PGt) testing and clinical decision support. PATIENTS & METHODS: Patients with history of acute myocardial infarction and percutaneous coronary intervention with no prior history of CYP2C19 testing. RESULTS: Four community pharmacies provided pharmacogenetic testing and medication therapy management services to 30 patients, resulting in eight recommendations for antiplatelet therapy adjustment. CONCLUSION: Pharmacists involved in the study were able to facilitate antiplatelet therapy adjustments based on PGt data regardless of baseline antiplatelet drug selection. Whereas prior literature largely revolved around PGt management in the inpatient setting, this project supports the involvement of the community pharmacist in making PGt-based recommendations.

20.
Endocrinology ; 129(4): 2131-8, 1991 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-1915093

RESUMO

The spontaneous decline of insulin secretion (third phase) that occurs under a variety of secretory conditions is well documented and suggests a general impairment or desensitization of the secretory process. We have examined several aspects of Ca2+ flux as well as regulators of Ca-linked second messenger events in freshly isolated rat islets chronically stimulated with glucose over 24 h, a period that encompasses initial (hour 1), peak (hour 3), and subsequent impaired or desensitized (hour 20-22) secretion. In islets incubated for these periods in HB104 medium with 22 mM glucose, 45Ca2+ uptake did not vary (12.6 +/- 1.6 vs. 10.2 +/- 1.7 vs. 13.2 +/- 3.4 pmol Ca2+/islet.10 min at 1, 3, and 22 h, respectively). Chronic incubation in 2 mM glucose reduced total Ca2+ uptake at each of the time periods, but, again, uptake did not change with desensitization (9.8 +/- 1.4 vs. 6.6 +/- 2.1 vs. 7.8 +/- 2.3 pmol Ca2+/islet.10 min). In 11 mM glucose, the Ca channel antagonist verapamil (1-10 microM) reduced insulin secretion by 55-80% in a dose-dependent manner over 1-3 h; islets continuously exposed to verapamil escaped inhibition by 20 h even at the highest concentration. However, in islets first exposed to 10 microM verapamil only during 20-22 h, hourly insulin secretion was suppressed 25%, 45%, and 33% at 20, 21, and 22 h, respectively, indicating that glucose-desensitized islets were still sensitive to further inhibition of Ca channels. Staurosporine (1 microM), an inhibitor of protein kinase-C activity, progressively inhibited glucose-stimulated insulin secretion from 48% at 1 h to more than 80% by 3 h; again, this inhibitory effect was lost by 20 h of chronic staurosporine. When staurosporine was first administered at 20 h, insulin secretion was modestly suppressed and returned to control values in the next hour. With continuous glucose, the islet response to positive stimulation of endogenous C-kinase activity by carbachol was maintained. The Ca/calmodulin inhibitor trifluoroperazine also inhibited insulin secretion by 75-80% during 1-3 h and continued to exert inhibitory effects through 23 h of continuous administration. We conclude that even though insulin secretion has desensitized to glucose, 1) Ca2+ entry is unchanged and is still regulated by glucose, 2) voltage-dependent Ca channels are still sensitive to blockade by acute verapamil, but can desensitize to chronic verapamil; 3) stimulus-enhanced C-kinase activity may be especially labile during glucose-induced desensitization, while 4) possible Ca/calmodulin potentiation of secretion persists through the three secretory phases.(ABSTRACT TRUNCATED AT 400 WORDS)


Assuntos
Cálcio/fisiologia , Glucose/farmacologia , Insulina/metabolismo , Alcaloides/farmacologia , Animais , Carbacol/farmacologia , Secreção de Insulina , Masculino , Proteína Quinase C/antagonistas & inibidores , Ratos , Ratos Endogâmicos , Estaurosporina , Fatores de Tempo , Trifluoperazina/farmacologia
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