Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 112
Filtrar
1.
Nature ; 584(7822): 614-618, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32612233

RESUMO

Oral antiretroviral agents provide life-saving treatments for millions of people living with HIV, and can prevent new infections via pre-exposure prophylaxis1-5. However, some people living with HIV who are heavily treatment-experienced have limited or no treatment options, owing to multidrug resistance6. In addition, suboptimal adherence to oral daily regimens can negatively affect the outcome of treatment-which contributes to virologic failure, resistance generation and viral transmission-as well as of pre-exposure prophylaxis, leading to new infections1,2,4,7-9. Long-acting agents from new antiretroviral classes can provide much-needed treatment options for people living with HIV who are heavily treatment-experienced, and additionally can improve adherence10. Here we describe GS-6207, a small molecule that disrupts the functions of HIV capsid protein and is amenable to long-acting therapy owing to its high potency, low in vivo systemic clearance and slow release kinetics from the subcutaneous injection site. Drawing on X-ray crystallographic information, we designed GS-6207 to bind tightly at a conserved interface between capsid protein monomers, where it interferes with capsid-protein-mediated interactions between proteins that are essential for multiple phases of the viral replication cycle. GS-6207 exhibits antiviral activity at picomolar concentrations against all subtypes of HIV-1 that we tested, and shows high synergy and no cross-resistance with approved antiretroviral drugs. In phase-1 clinical studies, monotherapy with a single subcutaneous dose of GS-6207 (450 mg) resulted in a mean log10-transformed reduction of plasma viral load of 2.2 after 9 days, and showed sustained plasma exposure at antivirally active concentrations for more than 6 months. These results provide clinical validation for therapies that target the functions of HIV capsid protein, and demonstrate the potential of GS-6207 as a long-acting agent to treat or prevent infection with HIV.


Assuntos
Fármacos Anti-HIV/farmacologia , Fármacos Anti-HIV/uso terapêutico , Proteínas do Capsídeo/antagonistas & inibidores , HIV-1/efeitos dos fármacos , Adolescente , Adulto , Fármacos Anti-HIV/química , Proteínas do Capsídeo/genética , Proteínas do Capsídeo/metabolismo , Linhagem Celular , Células Cultivadas , Farmacorresistência Viral/genética , Feminino , HIV-1/crescimento & desenvolvimento , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Moleculares , Replicação Viral/efeitos dos fármacos , Adulto Jovem
2.
J Pharmacol Exp Ther ; 391(1): 91-103, 2024 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-39117460

RESUMO

Lenacapavir (LEN), a long-acting injectable, is the first approved human immunodeficiency virus type 1 capsid inhibitor and one of a few Food and Drug Administration-approved drugs that exhibit atropisomerism. LEN exists as a mixture of two class 2 atropisomers that interconvert at a fast rate (half-life < 2 hours) with a ratio that is stable over time and unaffected by enzymes or binding to proteins in plasma. LEN exhibits low systemic clearance (CL) in nonclinical species and humans; however, in all species, the observed CL was higher than the in vitro predicted CL. The volume of distribution was moderate in nonclinical species and consistent with the tissue distribution observed by whole-body autoradiography in rats. LEN does not distribute to brain, consistent with being a P-glycoprotein (P-gp) substrate. Mechanistic drug disposition studies with [14C]LEN in intravenously dosed bile duct-cannulated rats and dogs showed a substantial amount of unchanged LEN (31%-60% of dose) excreted in feces, indicating that intestinal excretion (IE) was a major clearance pathway for LEN in both species. Coadministration of oral elacridar, a P-gp inhibitor, in rats decreased CL and IE of LEN. Renal excretion was < 1% of dose in both species. In plasma, almost all radioactivity was unchanged LEN. Low levels of metabolites in excreta included LEN conjugates with glutathione, pentose, and glucuronic acid, which were consistent with metabolites formed in vitro in Hµrel hepatocyte cocultures and those observed in human. Our studies highlight the importance of IE for efflux substrates that are highly metabolically stable compounds with slow elimination rates. SIGNIFICANCE STATEMENT: LEN is a long-acting injectable that exists as conformationally stable atropisomers. Due to an atropisomeric interconversion rate that significantly exceeds the in vivo elimination rate, the atropisomer ratio of LEN remains constant in circulation. The disposition of LEN highlights that intestinal excretion has a substantial part in the elimination of compounds that are metabolically highly stable and efflux transporter substrates.


Assuntos
Ratos Sprague-Dawley , Animais , Ratos , Humanos , Masculino , Cães , Distribuição Tecidual , Eliminação Intestinal , Quinolinas/farmacocinética , Taxa de Depuração Metabólica , Isomerismo
3.
Chem Rev ; 122(14): 12046-12109, 2022 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-35763791

RESUMO

One of the hallmark advances in our understanding of metalloprotein function is showcased in our ability to design new, non-native, catalytically active protein scaffolds. This review highlights progress and milestone achievements in the field of de novo metalloprotein design focused on reports from the past decade with special emphasis on de novo designs couched within common subfields of bioinorganic study: heme binding proteins, monometal- and dimetal-containing catalytic sites, and metal-containing electron transfer sites. Within each subfield, we highlight several of what we have identified as significant and important contributions to either our understanding of that subfield or de novo metalloprotein design as a discipline. These reports are placed in context both historically and scientifically. General suggestions for future directions that we feel will be important to advance our understanding or accelerate discovery are discussed.


Assuntos
Metaloproteínas , Sítios de Ligação , Catálise , Domínio Catalítico , Elétrons , Metaloproteínas/metabolismo , Modelos Moleculares
4.
Mol Pharm ; 20(12): 6213-6225, 2023 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-37917742

RESUMO

Lenacapavir (LEN) is a picomolar first-in-class capsid inhibitor of human immunodeficiency virus type 1 (HIV-1) with a multistage mechanism of action and no known cross resistance to other existing antiretroviral (ARV) drug classes. LEN exhibits a low aqueous solubility and exceptionally low systemic clearance following intravenous (IV) administration in nonclinical species and humans. LEN formulated in an aqueous suspension or a PEG/water solution formulation showed sustained plasma exposure levels with no unintended rapid drug release following subcutaneous (SC) administration to rats and dogs. A high total fraction dose release was observed with both formulations. The long-acting pharmacokinetics (PK) were recapitulated in humans following SC administration of both formulations. The SC PK profiles displayed two-phase absorption kinetics in both animals and humans with an initial fast-release absorption phase, followed by a slow-release absorption phase. Noncompartmental and compartmental analyses informed the LEN systemic input rate from the SC depot and exit rate from the body. Modeling-enabled deconvolution of the input rates from two processes: absorption of the soluble fraction (minor) from a direct fast-release process leading to the early PK phase and absorption of the precipitated fraction (major) from an indirect slow-release process leading to the later PK phase. LEN SC PK showed flip-flop kinetics due to the input rate being substantially slower than the systemic exit rate. LEN input rates via the slow-release process in humans were slower than those in both rats and dogs. Overall, the combination of high potency, exceptional stability, and optimal release rate from the injection depot make LEN well suited for a parenteral long-acting formulation that can be administered once up to every 6 months in humans for the prevention and treatment of HIV-1.


Assuntos
Fármacos Anti-HIV , HIV-1 , Humanos , Ratos , Animais , Cães , Antirretrovirais , Capsídeo , Fármacos Anti-HIV/farmacologia , Proteínas do Capsídeo
5.
Heredity (Edinb) ; 122(4): 417-427, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30120366

RESUMO

Determining the processes responsible for phenotypic variation is one of the central tasks of evolutionary biology. While the importance of acoustic traits for foraging and communication in echolocating mammals suggests adaptation, the seldom-tested null hypothesis to explain trait divergence is genetic drift. Here we derive FST values from multi-locus coalescent isolation-with-migration models, and couple them with estimates of quantitative trait divergence, or PST, to test drift as the evolutionary process responsible for phenotypic divergence in island populations of the Pteronotus parnellii species complex. Compared to traditional comparisons of PST to FST, the migration-based estimates of FST are unidirectional instead of bidirectional, simultaneously integrate variation among loci and individuals, and posterior densities of PST and FST can be compared directly. We found the evolution of higher call frequencies is inconsistent with genetic drift for the Hispaniolan population, despite many generations of isolation from its Puerto Rican counterpart. While the Hispaniolan population displays dimorphism in call frequencies, the higher frequency of the females is incompatible with sexual selection. Instead, cultural drift toward higher frequencies among Hispaniolan females might explain the divergence. By integrating Bayesian coalescent and trait analyses, this study demonstrates a powerful approach to testing genetic drift as the default evolutionary mechanism of trait differentiation between populations.


Assuntos
Quirópteros/genética , Ecolocação , Deriva Genética , Modelos Genéticos , Acústica , Animais , Teorema de Bayes , Quirópteros/fisiologia , DNA Mitocondrial/genética , Feminino , Variação Genética , Genótipo , Ilhas , Fenótipo , Característica Quantitativa Herdável
6.
Inorg Chem ; 57(15): 9564-9575, 2018 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-30040401

RESUMO

Anthracene-bridged dinuclear rhenium complexes are reported for electrocatalytic carbon dioxide (CO2) reduction to carbon monoxide (CO). Related by hindered rotation of each rhenium active site to either side of the anthracene bridge, cis and trans conformers have been isolated and characterized. Electrochemical studies reveal distinct mechanisms, whereby the cis conformer operates via cooperative bimetallic CO2 activation and conversion and the trans conformer reduces CO2 through well-established single-site and bimolecular pathways analogous to Re(bpy)(CO)3Cl. Higher turnover frequencies are observed for the cis conformer (35.3 s-1) relative to the trans conformer (22.9 s-1), with both outperforming Re(bpy)(CO)3Cl (11.1 s-1). Notably, at low applied potentials, the cis conformer does not catalyze the reductive disproportionation of CO2 to CO and CO32- in contrast to the trans conformer and mononuclear catalyst, demonstrating that the orientation of active sites and structure of the dinuclear cis complex dictate an alternative catalytic pathway. Further, UV-vis spectroelectrochemical experiments demonstrate that the anthracene bridge prevents intramolecular formation of a deactivated Re-Re-bonded dimer. Indeed, the cis conformer also avoids intermolecular Re-Re bond formation.

7.
Biochim Biophys Acta ; 1853(5): 1174-81, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25728284

RESUMO

Downregulation of multiple cell cycle-regulatory molecules is a dominant event in TGF-ß1-mediated growth inhibition of human carcinoma cells. It is known that KLF10 mimics the anti-proliferative and apoptotic effects that TGF-ß1 has on epithelial cell growth and the growth of various tumor cells; based on these findings it is considered as a tumor suppressor. KLF10 protein expression is tightly associated with cell cycle-dependent events. However, the regulatory mechanism and its biological meaning have not been identified. In this study, we have demonstrated that KLF10 is a substrate of CDK2/cyclin E and can be phosphorylated. We also have shown that KLF10 efficiently binds to CDK2, while binding much less to CDK4, and displaying no binding to Cdk6. Using mass spectrometry, site direct mutagenesis, in vitro kinase assays and depletion assays, we have established that CDK2 phosphorylates Ser206, which subsequently affects the steady state level of KLF10 in cells. Our studies have also proved that CDK2 up-regulates the protein level of KLF10 through reducing its association with SIAH1, a KLF10 E3-ubiqutin ligase involved in proteasomal degradation. Taken all together, these findings indicate that CDK2-dependent phosphorylation regulates KLF10 stability and that this affects the role of KLF10 in cell.


Assuntos
Quinase 2 Dependente de Ciclina/metabolismo , Fatores de Transcrição de Resposta de Crescimento Precoce/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismo , Proteínas Nucleares/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Sequência de Aminoácidos , Linhagem Celular Tumoral , Fatores de Transcrição de Resposta de Crescimento Precoce/química , Humanos , Fatores de Transcrição Kruppel-Like/química , Dados de Sequência Molecular , Fosforilação , Fosfosserina/metabolismo , Ligação Proteica , Estabilidade Proteica
8.
Biochim Biophys Acta ; 1833(12): 3035-3045, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23994618

RESUMO

KLF10 is now classified as a member of the Krüppel-like transcription factor family and acts as a tumor suppressor. Although KLF10 is originally named as TGF-ß-inducible early gene-1 and mimicking the anti-proliferative effect of TGF-ß in various carcinoma cells, the transcriptional upregulatory function of KLF10 has been described for a variety of cytokines and in many diseases. Through in vivo and in vitro phosphorylation assays, we identified that KLF10 is a phosphorylated protein in cells. Using yeast-two hybrid screening and site direct mutagenesis, we also identified PIN1 as a novel KLF10 associated protein. PIN1 is a peptidyl-prolyl isomerase enzyme belonging to the parvulin family, which specifically recognizes phosphorylated Ser/Thr-Pro containing substrates. Through protein-protein interaction assays, we showed that the Pro-directed Ser/Thr-Pro motif at Thr-93 in the KLF10 N-terminal region is essential for the interaction between KLF10 and PIN1. More importantly, PIN1 interacts with KLF10 in a phosphorylation-dependent manner and this interaction promotes KLF10 protein degradation in cells. Therefore, KLF10 shows shorter protein stability compared with mutant KLF10 that lacks PIN1 binding ability after cycloheximide treatments. The reversely correlated expression profile between KLF10 and PIN1 as observed in cell lines was also shown in clinic pancreatic cancer specimen. Using in vitro kinase assays and depletion assays, we were able to show that RAF-1 phosphorylates the Thr-93 of KLF10 and affects the KLF10 expression level in cells. Thus these findings as a whole indicate that RAF-1 phosphorylation and PIN1 isomerization together regulate KLF10 stability and further affect the role of KLF10 in tumor progression.


Assuntos
Fatores de Transcrição de Resposta de Crescimento Precoce/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismo , Peptidilprolil Isomerase/metabolismo , Fosfotreonina/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Motivos de Aminoácidos , Animais , Linhagem Celular Tumoral , Fatores de Transcrição de Resposta de Crescimento Precoce/química , Humanos , Fatores de Transcrição Kruppel-Like/química , Camundongos , Peptidilprolil Isomerase de Interação com NIMA , Fosforilação , Fosfosserina/metabolismo , Ligação Proteica , Mapeamento de Interação de Proteínas , Estabilidade Proteica , Proteólise , Proteínas Proto-Oncogênicas c-raf/metabolismo , Proteínas Supressoras de Tumor/química
9.
ACS Catal ; 14(6): 4362-4368, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-39157175

RESUMO

Herein, we report a three stranded coiled-coil (3SCC) de novo protein containing a type II copper center (CuT2) composed of 6-membered ring N-heterocycles. This design yields the most active homogenous copper nitrite reductase (CuNiR) mimic in water. We achieved this result by controlling three factors. First, previous studies with Nδ and Nε -Methyl Histidine had indicated that a ligand providing pyridine-like electronic character to the copper site was superior to the more donating Nδ for nitrite reduction. By substitution of the parent histidine with the non-coded amino acids pyridyl alanine (3'-Pyridine [3'Py] vs 4'-Pyridine [4'Py]), an authentic pyridine donor was employed without the complications of the coupling of both electronic and tautomeric effects of histidine or methylated histidine. Second, by changing the position of the nitrogen atom within the active site (4'-Pyridine vs. 3'Pyridine) a doubling of the enzyme's catalytic efficiency resulted. This effect was driven exclusivity by substrate binding to the copper site. Third, we replaced the leucine layer adjacent to the active site with an alanine, and the disparity between the 3'Py and 4'Py became more apparent. The decreased steric bulk minimally impacted the 3'Py derivative; however, the 4'Py K m decreased by an order of magnitude (600 mM to 50 mM), resulting in a 40-fold enhancement in the k cat/K m compared to the analogues histidine site and a 1500-fold improvement compared with the initially reported CuNiR catalyst of this family, TRIW-H. When combined with XANES/EXAFS data, the relaxing of the Cu(I) site to a more 2-coordinate Cu(I) like structure in the resting state increases the overall catalytic efficiency of nitrite reduction via the lowering of K m. This study illustrates how by combining advanced spectroscopic methods, detailed kinetic analysis, and a broad toolbox of amino acid side chain functionality, one can rationally design systems that optimize biomimetic catalysis.

10.
Complement Ther Clin Pract ; 57: 101908, 2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-39293126

RESUMO

BACKGROUND: Opioid abuse and mortality are ravaging American society, highlighting the need to find alternative effective analgesics with fewer side effects. FDA-approved topical analgesics, including non-steroidal anti-inflammatory drugs (NSAIDs), are commonly used to treat musculoskeletal pain but can cause adverse effects. Natural compounds, including essential oils, are potential therapeutic alternatives for managing musculoskeletal pain. If these compounds can provide comparable analgesia to FDA-approved products, it will increase the available options for people with pain, improving quality of life with minimal morbidity and mortality. OBJECTIVE: This study assesses the effectiveness and onset of action of Bonipar, a topical analgesic formulated with camphor, methyl salicylate, and oils of coconut, eucalyptus, nutmeg, and rosemary, in managing musculoskeletal pain compared to 1.5 % diclofenac solution, an FDA-approved topical non-steroidal anti-inflammatory drug. METHODS: One hundred sixty-four adult patients with localized musculoskeletal pain were randomly assigned to twice-daily applications of either Bonipar or Diclofenac for one week. The primary outcome measure was a 50 % reduction in pain after one week. Secondary outcomes included the change in pain from baseline and onset of action, defined as the first reduction in pain by 20 %. RESULTS: All patients completed the initial pain assessment to determine the onset of action. One-week data was available for 74 patients treated with diclofenac and 72 patients treated with Bonipar. Data for 18 patients were incomplete. The proportion of patients achieving a 50 % reduction in pain was statistically similar between the two groups. The success rates of achieving a 50 % pain reduction with Bonipar were found to be non-inferior to those treated with diclofenac. All follow-up time points showed roughly similar results between the groups. Regression models adjusted for age and sex revealed no significant effects on pain changes. Secondary analyses demonstrated no significant differences between the groups. DISCUSSION: The topical analgesic Bonipar demonstrates a comparable onset of action, with efficacy non-inferior to diclofenac in the management of musculoskeletal pain, while showing fewer adverse effects compared to diclofenac. These findings highlight the potential of Bonipar as a valuable alternative for the treatment of localized pain.

11.
Am J Pathol ; 181(2): 423-30, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22688058

RESUMO

Deregulation of transforming growth factor (TGF)-ß function is a common feature of pancreatic cancer, rendering these cancers unresponsive to TGF-ß-stimulated growth inhibition. Recent findings have supported a primary role for Krüppel-like factor 10 (KLF10) as an important transcription factor involved in mediating TGF-ß1 signaling. The aim of this study was to evaluate the correlation between KLF10 expression and the clinical and pathologic features of pancreatic cancer. Tissue specimens from patients with pancreatic adenocarcinoma were retrospectively collected for immunohistochemical analysis. To demonstrate that Klf10 expression was primarily regulated by methylation status, the Klf10 promoter was examined by methylation-specific PCR using a pancreatic cancer cell line (Panc-1). DNA methyltransferase (DNMT) inhibitor and small-interfering RNA depletion of DNMT genes were used to reverse KLF10 expression in the Panc-1 cells. In parallel, DNMT1 expression was evaluated in the pancreatic cancer tissue specimens. In 95 pancreatic cancer tissue specimens, KLF10 expression was inversely correlated with pancreatic cancer stage (P = 0.01). Multivariable analysis revealed that, in addition to the presence of distant metastasis at diagnosis (P = 0.001 and 0.001, respectively), KLF10 was another independent prognostic factor related to progression-free and overall survival (P = 0.018 and 0.037, respectively). The loss of KLF10 expression in advanced pancreatic cancer is correlated with altered methylation status, which seems to be regulated by DNMT1. Our results suggest that KLF10 is a potential clinical predictor for progression of pancreatic cancer.


Assuntos
Adenocarcinoma/diagnóstico , Adenocarcinoma/genética , Fatores de Transcrição de Resposta de Crescimento Precoce/genética , Fatores de Transcrição de Resposta de Crescimento Precoce/metabolismo , Fatores de Transcrição Kruppel-Like/genética , Fatores de Transcrição Kruppel-Like/metabolismo , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/genética , Adenocarcinoma/enzimologia , Adenocarcinoma/patologia , Idoso , Linhagem Celular Tumoral , DNA (Citosina-5-)-Metiltransferase 1 , DNA (Citosina-5-)-Metiltransferases/metabolismo , Metilação de DNA/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Análise de Sequência com Séries de Oligonucleotídeos , Neoplasias Pancreáticas/enzimologia , Neoplasias Pancreáticas/patologia , Prognóstico , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Análise de Sobrevida
12.
PLoS Pathog ; 6(8): e1001064, 2010 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-20865163

RESUMO

In contrast to HIV infection in humans and SIV in macaques, SIV infection of natural hosts including sooty mangabeys (SM) is non-pathogenic despite robust virus replication. We identified a novel SM CCR5 allele containing a two base pair deletion (Δ2) encoding a truncated molecule that is not expressed on the cell surface and does not support SIV entry in vitro. The allele was present at a 26% frequency in a large SM colony, along with 3% for a CCR5Δ24 deletion allele that also abrogates surface expression. Overall, 8% of animals were homozygous for defective CCR5 alleles and 41% were heterozygous. The mutant allele was also present in wild SM in West Africa. CD8+ and CD4+ T cells displayed a gradient of CCR5 expression across genotype groups, which was highly significant for CD8+ cells. Remarkably, the prevalence of natural SIVsmm infection was not significantly different in animals lacking functional CCR5 compared to heterozygous and homozygous wild-type animals. Furthermore, animals lacking functional CCR5 had robust plasma viral loads, which were only modestly lower than wild-type animals. SIVsmm primary isolates infected both homozygous mutant and wild-type PBMC in a CCR5-independent manner in vitro, and Envs from both CCR5-null and wild-type infected animals used CXCR6, GPR15 and GPR1 in addition to CCR5 in transfected cells. These data clearly indicate that SIVsmm relies on CCR5-independent entry pathways in SM that are homozygous for defective CCR5 alleles and, while the extent of alternative coreceptor use in SM with CCR5 wild type alleles is uncertain, strongly suggest that SIVsmm tropism and host cell targeting in vivo is defined by the distribution and use of alternative entry pathways in addition to CCR5. SIVsmm entry through alternative pathways in vivo raises the possibility of novel CCR5-negative target cells that may be more expendable than CCR5+ cells and enable the virus to replicate efficiently without causing disease in the face of extremely restricted CCR5 expression seen in SM and several other natural host species.


Assuntos
Cercocebus atys/genética , Receptores CCR5/genética , Síndrome de Imunodeficiência Adquirida dos Símios/genética , Vírus da Imunodeficiência Símia/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Linhagem Celular , Separação Celular , Citometria de Fluxo , Genótipo , Humanos , Dados de Sequência Molecular , Mutação , Reação em Cadeia da Polimerase , Receptores CCR5/biossíntese , Transfecção , Carga Viral/genética
13.
Cult Health Sex ; 14(5): 549-62, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22509909

RESUMO

In Canada, there is a paucity of research aimed at understanding Black gay men and the antecedents to risk factors for HIV. This study is an attempt to move beyond risk factor analysis and explore the role of sexual and ethnic communities in the lives of these men. The study utilized a community-based research and critical race theory approach. Semi-structured interviews were conducted with eight key informants to augment our understanding of Black gay men and to facilitate recruitment of participants. In-depth interviews were done with 24 Black gay men. Our data showed that the construction of community for Black gay men is challenged by their social and cultural environment. However, these men use their resilience to navigate gay social networks. Black gay men expressed a sense of abjuration from both gay and Black communities because of homophobia and racism. It is essential for health and social programmers to understand how Black gay men interact with Black and gay communities and the complexities of their interactions in creating outreach educational, preventive and support services.


Assuntos
População Negra/psicologia , Infecções por HIV/psicologia , Conhecimentos, Atitudes e Prática em Saúde , Homossexualidade Masculina/psicologia , Preconceito , Adulto , África/etnologia , Região do Caribe/etnologia , Pesquisa Participativa Baseada na Comunidade , Cultura , Infecções por HIV/epidemiologia , Infecções por HIV/etnologia , Inquéritos Epidemiológicos , Humanos , Entrevista Psicológica , Masculino , Ontário/epidemiologia , Ontário/etnologia , Psicometria , Características de Residência , Assunção de Riscos , Meio Social , Percepção Social , Apoio Social , Adulto Jovem
14.
Int J Neonatal Screen ; 8(1)2022 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-35225931

RESUMO

Newborn bloodspot screening (NBS) began as a research project in the Philippines in 1996 and was mandated by law in 2004. The program initially included screening for five conditions, with a sixth added in 2012. As screening technology and medical knowledge have advanced, NBS programs in countries with developed economies have also expanded, not only in the number of newborns screened but also in the number of conditions included in the screening. Various approaches have been taken regarding selection of conditions to be screened. With limited resources, low- and middle-income countries face significant challenges in selecting conditions for screening and in implementing sustainable screening programs. Building on expansion experiences in the U.S. and data from California on Filipinos born and screened there, the Philippine NBS program has recently completed its expansion to include 29 screening conditions. This report focuses on those conditions detectable through tandem mass spectrometry. Expanded screening was implemented in a stepwise fashion across the seven newborn screening laboratories in the Philippines. A university-based biochemical genetics laboratory provides confirmatory testing. Follow-up care for confirmed cases is monitored and provided through the NBS continuity clinics across the archipelago. Pre-COVID-19 pandemic, the coverage was 91.6% but dropped to 80.4% by the end of 2020 due to closure of borders between cities, provinces, and islands.

15.
J Hand Surg Am ; 36(4): 604-9, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21315521

RESUMO

PURPOSE: To retrospectively review the outcomes of intra-articularly placed interfragmentary screws for fixation of difficult condylar fractures of the metacarpal and proximal phalangeal heads. METHODS: We placed interfragmentary screws intra-articularly in 10 patients with 11 fractures to achieve a rigid fixation construct in which the non-articular portion of the bone fragment is too small to allow a stable fixation, or where the bone fragment is entirely osteochondral. RESULTS: The mean duration of follow-up was 15.9 months (range, 6-45 mo). All fractures united within 16 weeks (average, 8.1 wk). We observed subsidence in 1 case; another patient had screw protrusion that required removal. The range of motion of the involved metacarpophalangeal joints for the metacarpal head fractures was 79° (range, 60° to 90°). The range of motion of the involved proximal interphalangeal joints for the proximal phalangeal head fractures was 86° (range, 80° to 90°). CONCLUSIONS: Intra-articularly placed interfragmentary screw fixation is a good technique for treating difficult condylar fractures of the hand.


Assuntos
Parafusos Ósseos , Traumatismos dos Dedos/cirurgia , Fixação Interna de Fraturas/instrumentação , Fraturas Intra-Articulares/cirurgia , Adolescente , Adulto , Estudos de Coortes , Feminino , Traumatismos dos Dedos/diagnóstico por imagem , Articulações dos Dedos/cirurgia , Fixação Interna de Fraturas/métodos , Consolidação da Fratura/fisiologia , Humanos , Escala de Gravidade do Ferimento , Fraturas Intra-Articulares/diagnóstico por imagem , Masculino , Articulação Metacarpofalângica/lesões , Articulação Metacarpofalângica/cirurgia , Pessoa de Meia-Idade , Radiografia , Amplitude de Movimento Articular/fisiologia , Recuperação de Função Fisiológica , Estudos Retrospectivos , Medição de Risco , Adulto Jovem
16.
Front Mol Biosci ; 8: 751938, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34869587

RESUMO

Krüppel-like factor 10 (KLF10) is a phospho-regulated transcriptional factor involved in many biological processes including lipogenesis; however, the transcriptional regulation on lipogenesis by KLF10 remains largely unclear. Lipogenesis is important in the development of nonalcoholic fatty liver disease (NAFLD) which was known regulated mainly by AMP-activated protein kinase (AMPK) and sterol regulatory element-binding protein (SREBP-1C). Interesting, our previous study using phosphorylated site prediction suggested a regulation of AMPK on KLF10. Therefore, we aimed to study the protein-protein interactions of AMPK on the regulation of KLF10, and to delineate the mechanisms of phosphorylated KLF10 in the regulation of NAFLD through SREBP-1C. We performed in vitro and in vivo assays that identified AMPK phosphorylates KLF10 at Thr189 and subsequently modulates the steady state level of KLF10. Meanwhile, a chromatin immunoprecipitation-chip assay revealed the novel target genes and signaling cascades of corresponding to phosphorylated KLF10. SREBP-1C was identified as a target gene suppressed by phosphorylated KLF10 through promoter binding. We further performed high-fat-diet-induced NAFLD models using hepatic-specific KLF10 knockout mice and wild-type mice and revealed that KLF10 knockout markedly led to more severe NAFLD than that in wild-type mice. Taken together, our findings revealed for the first time that AMPK activates and stabilizes the KLF10 protein via phosphorylation at Thr189, thereby repressing the expression of SREBP-1C and subsequent lipogenesis pathways along with metabolic disorders. We suggested that the targeted manipulation of liver metabolism, particularly through increased KLF10 expression, is a potential alternative solution for treating NAFLD.

17.
Int J Neonatal Screen ; 7(2)2021 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-34204320

RESUMO

The Philippine newborn bloodspot screening (NBS) program began in 1996 with 24 hospitals and was formalized by legislation in 2004. The NBS panel was recently expanded to include a number of additional hereditary congenital conditions. Expertise and experiences from other NBS programs already screening for hemoglobinopathies were essential to its successful integration into the ongoing dried bloodspot NBS program in the Philippines. Building on clinical experiences and population data from Filipinos born in California, USA, hemoglobinopathies (including thalassemias) were selected for inclusion in the expanded screening panel. Hemoglobinopathy NBS, using high performance liquid chromatography, was implemented in a stepwise manner into the seven regional NBS screening laboratories. A central university laboratory provides confirmatory testing using both capillary electrophoresis and molecular methodologies. NBS results indicating carriers are followed up with educational fact sheets, while results of presumptive disease are referred for confirmatory testing and follow-up with a hematologist. Long-term care is provided through newborn screening continuity clinics across the country. Hemoglobinopathy NBS is now included in the national insurance package and screening uptake continues to increase nationally, exceeding 90% of all newborns in 7400+ hospitals and birthing centers nationwide prior to the COVID-19 pandemic.

18.
Curr Allergy Asthma Rep ; 10(3): 181-7, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20425008

RESUMO

The first US Food and Drug Administration-approved dilating balloon catheter system for obstructed paranasal sinus drainage pathways was introduced in September 2005. It was discussed as an alternative treatment option for traditional endoscopic sinus surgery for those suffering from chronic rhinosinusitis. Widespread patient interest has ensued, although controversy regarding application of this device continues. Many otolaryngologists have been trained to use the device, and more than 88,000 patients have had surgery using this device. Like similar dilating catheters used in other specialties to relieve obstruction, it is a minimally invasive tool for mucosal-sparing dilation of sinus ostia or sinus outflow tracts. Although studies have been completed that demonstrate feasibility, safety, and long-term patency of dilated sinuses, the evolving indications for its use remain controversial. Referring physicians and patients can expect a range of opinions on the role of these devices in the treatment of rhinosinusitis for the foreseeable future.


Assuntos
Rinite/terapia , Sinusite/terapia , Cateterismo , Endoscopia , Humanos , Mucosa Nasal , Otolaringologia , Seios Paranasais/cirurgia , Resultado do Tratamento , Estados Unidos , United States Food and Drug Administration
19.
Science ; 245(4919): 707-11, 1989 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-17791709

RESUMO

An assessment of the effects of airline deregulation on travelers and carriers indicates that deregulation has provided travelers and carriers with $14.9 billion of annual benefits (1988 dollars). Airport congestion, airline safety, airline bankruptcy, and mergers are also analyzed and found in most cases to have reduced benefits. But, these costs should not be attributed to deregulation per se, but to failures by the government to pursue appropriate policies in these areas. Pursuit of policies that promote airline competition and efficient use of airport capacity would significantly increase the benefits from deregulation and would provide valuable guidance for other industries undergoing the transition to deregulation.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA