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1.
Cell ; 134(1): 48-61, 2008 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-18614010

RESUMO

A major part of virulence for Plasmodium falciparum malaria infection, the most lethal parasitic disease of humans, results from increased rigidity and adhesiveness of infected host red cells. These changes are caused by parasite proteins exported to the erythrocyte using novel trafficking machinery assembled in the host cell. To understand these unique modifications, we used a large-scale gene knockout strategy combined with functional screens to identify proteins exported into parasite-infected erythrocytes and involved in remodeling these cells. Eight genes were identified encoding proteins required for export of the parasite adhesin PfEMP1 and assembly of knobs that function as physical platforms to anchor the adhesin. Additionally, we show that multiple proteins play a role in generating increased rigidity of infected erythrocytes. Collectively these proteins function as a pathogen secretion system, similar to bacteria and may provide targets for antivirulence based therapies to a disease responsible for millions of deaths annually.


Assuntos
Eritrócitos/citologia , Eritrócitos/parasitologia , Malária Falciparum/parasitologia , Plasmodium falciparum/patogenicidade , Proteínas de Protozoários/metabolismo , Animais , Adesão Celular , Forma Celular , Membrana Eritrocítica/química , Humanos , Plasmodium falciparum/metabolismo , Transporte Proteico , Proteínas de Protozoários/análise , Proteínas de Protozoários/genética , Virulência
2.
Nature ; 530(7590): 358-61, 2016 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-26887496

RESUMO

Retroviral integrase catalyses the integration of viral DNA into host target DNA, which is an essential step in the life cycle of all retroviruses. Previous structural characterization of integrase-viral DNA complexes, or intasomes, from the spumavirus prototype foamy virus revealed a functional integrase tetramer, and it is generally believed that intasomes derived from other retroviral genera use tetrameric integrase. However, the intasomes of orthoretroviruses, which include all known pathogenic species, have not been characterized structurally. Here, using single-particle cryo-electron microscopy and X-ray crystallography, we determine an unexpected octameric integrase architecture for the intasome of the betaretrovirus mouse mammary tumour virus. The structure is composed of two core integrase dimers, which interact with the viral DNA ends and structurally mimic the integrase tetramer of prototype foamy virus, and two flanking integrase dimers that engage the core structure via their integrase carboxy-terminal domains. Contrary to the belief that tetrameric integrase components are sufficient to catalyse integration, the flanking integrase dimers were necessary for mouse mammary tumour virus integrase activity. The integrase octamer solves a conundrum for betaretroviruses as well as alpharetroviruses by providing critical carboxy-terminal domains to the intasome core that cannot be provided in cis because of evolutionarily restrictive catalytic core domain-carboxy-terminal domain linker regions. The octameric architecture of the intasome of mouse mammary tumour virus provides new insight into the structural basis of retroviral DNA integration.


Assuntos
Microscopia Crioeletrônica , DNA Viral/metabolismo , DNA Viral/ultraestrutura , Integrases/química , Integrases/ultraestrutura , Vírus do Tumor Mamário do Camundongo/enzimologia , Multimerização Proteica , Domínio Catalítico , Cristalografia por Raios X , DNA Viral/química , Integrases/metabolismo , Vírus do Tumor Mamário do Camundongo/química , Vírus do Tumor Mamário do Camundongo/genética , Vírus do Tumor Mamário do Camundongo/ultraestrutura , Modelos Moleculares , Estrutura Quaternária de Proteína , Spumavirus/química , Spumavirus/enzimologia , Integração Viral
3.
Am J Perinatol ; 32(3): 299-306, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25093913

RESUMO

OBJECTIVE: Over 70% of women with gestational diabetes mellitus (GDM) will develop diabetes mellitus (DM), but only 30% follow through with the recommended postpartum oral glucose tolerance testing (OGTT). HbA1c is approved to diagnose DM, and combined with a fasting plasma glucose it can identify 93% of patients with dysglycemia. We tested the hypothesis that a single blood draw to assess for dysglycemia at the postpartum visit could improve testing rates compared with those required to obtain an OGTT at an outside laboratory. STUDY DESIGN: Prospective cohort study of all women with GDM who delivered between July 2010 and December 2011. When insurance status required testing at an outside laboratory an OGTT was ordered, when insurance allowed testing at our center a random sugar and HbA1c were drawn at the postpartum visit (SUGAR Protocol). RESULTS: Of the 40 women, 36 attended a postpartum visit. In the SUGAR arm, 19 of 19 (100%) were tested versus 9 of 17 (53%) in the OGTT arm; relative risk of testing was 1.9 (95% confidence interval, 1.2-3.0). 36% were glucose intolerant. CONCLUSION: This pilot study found that an in-office testing model doubled the rate of postpartum testing in this clinic population, and was reasonably sensitive at detecting dysglycemia.


Assuntos
Glicemia/química , Diabetes Gestacional/diagnóstico , Hemoglobinas Glicadas/química , Complicações na Gravidez/diagnóstico , Adulto , Jejum , Feminino , Teste de Tolerância a Glucose , Humanos , Projetos Piloto , Período Pós-Parto , Gravidez , Estudos Prospectivos , Adulto Jovem
4.
Res Sq ; 2024 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-38496675

RESUMO

Endocrine islet b cells comprise heterogenous cell subsets. Yet when/how these subsets are produced and how stable they are remain unknown. Addressing these questions is important for preventing/curing diabetes, because lower numbers of b cells with better secretory function is a high risk of this disease. Using combinatorial cell lineage tracing, scRNA-seq, and DNA methylation analysis, we show here that embryonic islet progenitors with distinct gene expression and DNA methylation produce b-cell subtypes of different function and viability in adult mice. The subtype with better function is enriched for genes involved in vesicular production/trafficking, stress response, and Ca2+-secretion coupling, which further correspond to differential DNA methylation in putative enhancers of these genes. Maternal overnutrition, a major diabetes risk factor, reduces the proportion of endocrine progenitors of the b-cell subtype with better-function via deregulating DNA methyl transferase 3a. Intriguingly, the gene signature that defines mouse b-cell subtypes can reliably divide human cells into two sub-populations while the proportion of b cells with better-function is reduced in diabetic donors. The implication of these results is that modulating DNA methylation in islet progenitors using maternal food supplements can be explored to improve b-cell function in the prevention and therapy of diabetes.

5.
PLoS One ; 19(4): e0298808, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38598488

RESUMO

Pancreatic ductal adenocarcinoma (PDAC) presents at advanced stages and is refractory to most treatment modalities. Wnt signaling activation plays a critical role in proliferation and chemotherapeutic resistance. Minimal media conditions, growth factor dependency, and Wnt dependency were determined via Wnt inhibition for seven patient derived organoids (PDOs) derived from pancreatic tumor organoid libraries (PTOL). Organoids demonstrating response in vitro were assessed in vivo using patient-derived xenografts. Wnt (in)dependent gene signatures were identified for each organoid. Panc269 demonstrated a trend of reduced organoid growth when treated with ETC-159 in combination with paclitaxel or gemcitabine as compared with chemotherapy or ETC-159 alone. Panc320 demonstrated a more pronounced anti-proliferative effect in the combination of ETC-159 and paclitaxel but not with gemcitabine. Panc269 and Panc320 were implanted into nude mice and treated with ETC-159, paclitaxel, and gemcitabine as single agents and in combination. The combination of ETC-159 and paclitaxel demonstrated an anti-tumor effect greater than ETC-159 alone. Extent of combinatory treatment effect were observed to a lesser extent in the Panc320 xenograft. Wnt (in)dependent gene signatures of Panc269 and 320 were consistent with the phenotypes displayed. Gene expression of several key Wnt genes assessed via RT-PCR demonstrated notable fold change following treatment in vivo. Each pancreatic organoid demonstrated varied niche factor dependencies, providing an avenue for targeted therapy, supported through growth analysis following combinatory treatment of Wnt inhibitor and standard chemotherapy in vitro. The clinical utilization of this combinatory treatment modality in pancreatic cancer PDOs has thus far been supported in our patient-derived xenograft models treated with Wnt inhibitor plus paclitaxel or gemcitabine. Gene expression analysis suggests there are key Wnt genes that contribute to the Wnt (in)dependent phenotypes of pancreatic tumors, providing plausible mechanistic explanation for Wnt (in)dependency and susceptibility or resistance to treatment on the genotypic level.


Assuntos
Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Animais , Camundongos , Humanos , Gencitabina , Via de Sinalização Wnt , Desoxicitidina/farmacologia , Desoxicitidina/uso terapêutico , Camundongos Nus , Proliferação de Células , Linhagem Celular Tumoral , Carcinoma Ductal Pancreático/tratamento farmacológico , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/metabolismo , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Paclitaxel/farmacologia , Paclitaxel/uso terapêutico , Organoides/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
6.
J Am Chem Soc ; 135(16): 6289-99, 2013 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-23581831

RESUMO

The design and characterization of α-ketoheterocycle fatty acid amide hydrolase (FAAH) inhibitors are disclosed that additionally and irreversibly target a cysteine (Cys269) found in the enzyme cytosolic port while maintaining the reversible covalent Ser241 attachment responsible for their rapid and initially reversible enzyme inhibition. Two α-ketooxazoles (3 and 4) containing strategically placed electrophiles at the C5 position of the pyridyl substituent of 2 (OL-135) were prepared and examined as inhibitors of FAAH. Consistent with the observed time-dependent noncompetitive inhibition, the cocrystal X-ray structure of 3 bound to a humanized variant of rat FAAH revealed that 3 was not only covalently bound to the active site catalytic nucleophile Ser241 as a deprotonated hemiketal, but also to Cys269 through the pyridyl C5-substituent, thus providing an inhibitor with dual covalent attachment in the enzyme active site. In vivo characterization of the prototypical inhibitors in mice demonstrates that they raise endogenous brain levels of FAAH substrates to a greater extent and for a much longer duration (>6 h) than the reversible inhibitor 2, indicating that the inhibitors accumulate and persist in the brain to completely inhibit FAAH for a prolonged period. Consistent with this behavior and the targeted irreversible enzyme inhibition, 3 reversed cold allodynia in the chronic constriction injury model of neuropathic pain in mice for a sustained period (>6 h) beyond that observed with the reversible inhibitor 2, providing effects that were unchanged over the 1-6 h time course monitored.


Assuntos
Amidoidrolases/antagonistas & inibidores , Inibidores Enzimáticos/química , Inibidores Enzimáticos/síntese química , Animais , Ligação Competitiva/efeitos dos fármacos , Química Encefálica/efeitos dos fármacos , Domínio Catalítico , Cristalografia por Raios X , Relação Dose-Resposta a Droga , Desenho de Fármacos , Inibidores Enzimáticos/farmacologia , Escherichia coli/metabolismo , Hiperalgesia/tratamento farmacológico , Indicadores e Reagentes , Cinética , Metabolismo dos Lipídeos/efeitos dos fármacos , Camundongos , Modelos Moleculares , Conformação Molecular , Neuralgia/tratamento farmacológico , Carbonilação Proteica , Ratos , Proteínas Recombinantes , Rodaminas , Especificidade por Substrato
7.
PLoS Pathog ; 7(11): e1002367, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22102814

RESUMO

Primary infection with varicella zoster virus (VZV) results in varicella (more commonly known as chickenpox) after which VZV establishes latency in sensory ganglia. VZV can reactivate to cause herpes zoster (shingles), a debilitating disease that affects one million individuals in the US alone annually. Current vaccines against varicella (Varivax) and herpes zoster (Zostavax) are not 100% efficacious. Specifically, studies have shown that 1 dose of varivax can lead to breakthrough varicella, albeit rarely, in children and a 2-dose regimen is now recommended. Similarly, although Zostavax results in a 50% reduction in HZ cases, a significant number of recipients remain at risk. To design more efficacious vaccines, we need a better understanding of the immune response to VZV. Clinical observations suggest that T cell immunity plays a more critical role in the protection against VZV primary infection and reactivation. However, no studies to date have directly tested this hypothesis due to the scarcity of animal models that recapitulate the immune response to VZV. We have recently shown that SVV infection of rhesus macaques models the hallmarks of primary VZV infection in children. In this study, we used this model to experimentally determine the role of CD4, CD8 and B cell responses in the resolution of primary SVV infection in unvaccinated animals. Data presented in this manuscript show that while CD20 depletion leads to a significant delay and decrease in the antibody response to SVV, loss of B cells does not alter the severity of varicella or the kinetics/magnitude of the T cell response. Loss of CD8 T cells resulted in slightly higher viral loads and prolonged viremia. In contrast, CD4 depletion led to higher viral loads, prolonged viremia and disseminated varicella. CD4 depleted animals also had delayed and reduced antibody and CD8 T cell responses. These results are similar to clinical observations that children with agammaglobulinemia have uncomplicated varicella whereas children with T cell deficiencies are at increased risk of progressive varicella with significant complications. Moreover, our studies indicate that CD4 T cell responses to SVV play a more critical role than antibody or CD8 T cell responses in the control of primary SVV infection and suggest that one potential mechanism for enhancing the efficacy of VZV vaccines is by eliciting robust CD4 T cell responses.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Varicela/imunologia , Modelos Animais de Doenças , Infecções por Herpesviridae/imunologia , Herpesvirus Humano 3/imunologia , Macaca mulatta , Varicellovirus/imunologia , Animais , Antígenos CD20/imunologia , Linfócitos B/imunologia , Antígenos CD4/imunologia , Linfócitos T CD8-Positivos/imunologia , Varicela/prevenção & controle , Varicela/virologia , Vacina contra Varicela/imunologia , Infecções por Herpesviridae/virologia , Varicellovirus/fisiologia , Carga Viral , Replicação Viral
8.
Allergy Asthma Proc ; 34(1): 103-7, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23406943

RESUMO

A 9-year-old African American boy presented with chronic urticaria and progressive spondyloarthritis. Laboratory tests were abnormal for persistently positive antinuclear antibodies and undetectable total hemolytic complement (CH50) despite normal levels of complement C2, C3, and C4. Ultimately, further testing revealed an underlying deficiency in the immune system that may be associated with autoimmune disease and thus have a bearing on the patient's urticaria and spondyloarthritis. This is a unique presentation of a rare disease and underscores the importance of evaluating for systemic disease in the workup of chronic urticaria.


Assuntos
Articulações/imunologia , Espondilite Anquilosante/diagnóstico , Urticária/diagnóstico , Anticorpos Antinucleares/sangue , Criança , Doença Crônica , Ensaio de Atividade Hemolítica de Complemento , Proteínas do Sistema Complemento/deficiência , Diagnóstico Diferencial , Progressão da Doença , Humanos , Masculino , Receptores de IgE/imunologia , Testes Sorológicos , Espondilite Anquilosante/etiologia , Urticária/complicações
9.
J Racial Ethn Health Disparities ; 10(3): 1358-1370, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-35534682

RESUMO

BACKGROUND: Underserved ethnic minorities with psychiatric disorders are at an increased risk of COVID-19. This study aims to examine the effectiveness of one-to-one counseling on COVID-19 vaccination and vaccination readiness among underserved African American and Latinx individuals with mental illnesses and adult caregivers of children with mental illness. METHODS: Through an academic-community partnered collaboration, a multidisciplinary and culturally sensitive training on COVID-19 was co-developed and delivered to 68 therapists from January to March 2021. Mental health clients and their caregivers were recruited to participate in pre- and post-intervention surveys to evaluate the impact of the intervention on their perceptions of COVID-19 public health guidelines, testing, and vaccination. Mental health therapists delivered four lessons of the COVID-19 educational intervention with 254 clients from March to June 2021, when vaccine availability was widely available. Of those clients, we collected 180 baseline and 115 follow-up surveys. The main outcome was the uptake in COVID-19 vaccine. RESULTS: There was a positive shift in participant vaccine acceptance and receptivity. Pre-intervention survey shows that only 56% of adult clients and 48% of caregivers had indicated a likelihood of getting the vaccine for themselves at baseline. Post-intervention documented that more than 57% of each group had been vaccinated, with another 11-15% of the unvaccinated individuals reporting that they were somewhat or very likely to get the vaccine. CONCLUSION: This study demonstrated that multidisciplinary academic-community and theoretical-based educational intervention delivered by mental health therapists is an effective strategy in increasing COVID-19 vaccine acceptance and reducing the negative impact and disruption that COVID-19 caused in the daily life of mental health patients and caregivers.


Assuntos
COVID-19 , Transtornos Mentais , Adulto , Criança , Humanos , Saúde Mental , Vacinas contra COVID-19/uso terapêutico , Hesitação Vacinal , Negro ou Afro-Americano , COVID-19/prevenção & controle , Transtornos Mentais/terapia , Hispânico ou Latino
10.
Inform Prim Care ; 20(2): 141-6, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23710778

RESUMO

BACKGROUND: The advent of more mobile, more reliable, and more affordable videoconferencing technology finally makes it realistic to offer remote foreign language interpretation in the office setting. Still, such technologies deserve proof of acceptability to clinicians and patients before there is widespread acceptance and routine use. OBJECTIVE: We sought to examine: (1) the audio and video technical fidelity of iPad/Facetime(TM) software, (2) the acceptability of videoconferencing to patients and clinicians. METHODS: The convenience sample included Spanish-speaking adult patients at a community health care medicine clinic in 2011. Videoconferencing was conducted using two iPads(TM) connecting patient/physician located in the clinic examination room, and the interpreter in a remote/separate office in the same building. A five-item survey was used to solicit opinions on overall quality of the videoconferencing device, audio/video integrity/fidelity, perception of encounter duration, and attitude toward future use. RESULTS: Twenty-five patients, 18 clinicians and 5 interpreters participated in the project. Most patients (24/25) rated overall quality of videoconferencing as good/excellent with only 1 'fair' rating. Eleven patients rated the amount of time as no longer than in-person, and nine reported it as shorter than inperson. Most patients, 94.0% (24/25), favoured using videoconferencing during future visits. For the 18 clinicians, the results were similar. CONCLUSIONS: Based on our experience at a singlesite community health centre, the videoconferencing technology appeared to be flawless, and both patients and clinicians were satisfied. Expansion of videoconferencing to other off-site healthcare professionals should be considered in the search for more cost-effective healthcare.


Assuntos
Atitude do Pessoal de Saúde , Satisfação do Paciente , Comunicação por Videoconferência/organização & administração , Adulto , Barreiras de Comunicação , Computadores de Mão , Feminino , Hispânico ou Latino , Humanos , Masculino , Relações Médico-Paciente , Projetos Piloto , Consulta Remota/economia , Consulta Remota/métodos , Tradução , Comunicação por Videoconferência/economia , Comunicação por Videoconferência/instrumentação
11.
J Emerg Nurs ; 38(3): 211-7, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-21435705

RESUMO

INTRODUCTION: The purposes of this study were to investigate the adequacy of pain management for patients with long-bone fractures seen in the emergency department and to determine whether racial disparities exist. METHODS: The design was an exploratory, correlational design using patient data abstract ed from electronic medical records of 2 major urban medical centers located in the Southeastern United States. Data collected included demographics, time of initial pain assessment by the registered nurse, time of pain medication administration, severity of pain, fracture location by radiograph, type of pain medication, and route-dosage of pain medication administered. The primary outcome variable, which was the pain management index, was calculated and used as a measure of adequate pain management. RESULTS: The majority of the sample (N = 218) was female (61%) and white (63%), with 28% black and about 10% of the sample consisting of other minorities. Seventy-nine (36%) of the 218 patients received no medication while in the emergency department despite a mean pain score of 6.9 (SD = 2.5) on a 0 to 10 scale representing moderate to severe pain. Patients who received pain medication (n = 126) waited for the medication 1.76 hours (±1.47). Among the patients who received an analgesic (n = 126), younger patients, black patients, and those with higher pain severity were more likely to receive inadequate pain management than were white patients. DISCUSSION: According to the pain management index, the majority of the patients in this study received inadequate pain management while in the emergency department. Future interventions may need to focus on giving ED nurses information about inadequate pain management and disparities in pain management in the ED setting and exploring possible reasons for disparities in order to ultimately improve patient care.


Assuntos
Analgésicos/administração & dosagem , Serviço Hospitalar de Emergência/organização & administração , Fraturas Ósseas/enfermagem , Manejo da Dor/enfermagem , Distribuição de Qui-Quadrado , Demografia , Feminino , Fraturas Ósseas/etnologia , Disparidades em Assistência à Saúde , Humanos , Masculino , Sistemas Computadorizados de Registros Médicos , Pessoa de Meia-Idade , Medição da Dor
12.
Cell Mol Gastroenterol Hepatol ; 13(3): 843-856, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34915204

RESUMO

The epithelial lining of the intestine, particularly the stem cell compartment, is affected by harsh conditions in the luminal environment and also is susceptible to genotoxic agents such as radiation and chemotherapy. Therefore, the ability for intestinal epithelial cells to revert to a stem cell state is an important physiological damage response to regenerate the intestinal epithelium at sites of mucosal injury. Many signaling networks involved in maintaining the stem cell niche are activated as part of the damage response to promote cellular plasticity and regeneration. The relative contribution of each cell type and signaling pathway is a critical area of ongoing research, likely dependent on the nature of injury as well as the regional specification within the intestine. Here, we review the current understanding of the multicellular cooperation to restore the intestinal epithelium after damage.


Assuntos
Plasticidade Celular , Nicho de Células-Tronco , Homeostase , Intestinos , Regeneração
13.
J Am Chem Soc ; 132(33): 11443-5, 2010 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-20669948

RESUMO

G protein-coupled receptors (GPCRs) represent a large fraction of current pharmaceutical targets, and of the GPCRs, the beta(2) adrenergic receptor (beta(2)AR) is one of the most extensively studied. Previously, the X-ray crystal structure of beta(2)AR has been determined in complex with two partial inverse agonists, but the global impact of additional ligands on the structure or local impacts on the binding site are not well-understood. To assess the extent of such ligand-induced conformational differences, we determined the crystal structures of a previously described engineered beta(2)AR construct in complex with two inverse agonists: ICI 118,551 (2.8 A), a recently described compound (2.8 A) (Kolb et al, 2009), and the antagonist alprenolol (3.1 A). The structures show the same overall fold observed for the previous beta(2)AR structures and demonstrate that the ligand binding site can accommodate compounds of different chemical and pharmacological properties with only minor local structural rearrangements. All three compounds contain a hydroxy-amine motif that establishes a conserved hydrogen bond network with the receptor and chemically diverse aromatic moieties that form distinct interactions with beta(2)AR. Furthermore, receptor ligand cross-docking experiments revealed that a single beta(2)AR complex can be suitable for docking of a range of antagonists and inverse agonists but also indicate that additional ligand-receptor structures may be useful to further improve performance for in-silico docking or lead-optimization in drug design.


Assuntos
Agonistas de Receptores Adrenérgicos beta 2/química , Antagonistas de Receptores Adrenérgicos beta 2/química , Receptores Adrenérgicos beta 2/química , Sítios de Ligação , Cristalografia por Raios X , Humanos , Ligantes , Modelos Moleculares , Estrutura Molecular
14.
Mol Microbiol ; 71(1): 48-65, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19007413

RESUMO

Virulence of Plasmodium falciparum, the most lethal parasitic disease in humans, results in part from adhesiveness and increased rigidity of infected erythrocytes. Pf332 is trafficked to the parasite-infected erythrocyte via Maurer's clefts, structures for protein sorting and export in the host erythrocyte. This protein has a domain similar to the Duffy-binding-like (DBL) domain, which functions by binding to receptors for adherence and invasion. To address structure of the Pf332 DBL domain, we expressed this region, and validated its fold on the basis of the disulphide bond pattern, which conformed to the generic pattern for DBL domains. The modelled structure for Pf332 DBL had differences compared with the erythrocyte-binding region of the alphaDBL domain of Plasmodium knowlesi Duffy-binding protein (Pk alpha-DBL). We addressed the function of Pf332 by constructing parasites that either lack expression of the protein or express an altered form. We found no evidence that Pf332 is involved in cytoadhesion or merozoite invasion. Truncation of Pf332 had a significant effect on deformability of the P. falciparum-infected erythrocyte, while loss of the full protein deletion did not. Our data suggest that Pf332 may contribute to the overall deformability of the P. falciparum-infected erythrocyte by anchoring and scaffolding.


Assuntos
Antígenos de Protozoários/metabolismo , Plasmodium falciparum/metabolismo , Proteínas de Protozoários/metabolismo , Animais , Anticorpos Antiprotozoários/imunologia , Anticorpos Antiprotozoários/metabolismo , Antígenos de Protozoários/fisiologia , Sítios de Ligação , Eritrócitos/parasitologia , Deleção de Genes , Humanos , Merozoítos/fisiologia , Modelos Moleculares , Mapeamento de Peptídeos , Plasmodium falciparum/fisiologia , Dobramento de Proteína , Domínios e Motivos de Interação entre Proteínas , Estrutura Terciária de Proteína , Proteínas de Protozoários/fisiologia , Relação Estrutura-Atividade
15.
Breast Cancer Res Treat ; 120(1): 217-27, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19629680

RESUMO

Breast cancer is the most common cancer among women. It is estimated that 7% of women who have breast cancer will develop a subsequent second independent breast tumor within 10 years of the first. The status of estrogen (ER), progesterone (PR) and human growth hormone (HER2) receptors, individually and as phenotypic combinations, impacts the clinical course of breast cancer and may impact the course of subsequent primary tumors and patient survival. Our aims were to determine tumor marker phenotype concordance between first and second primary breast cancers (FPBC and SPBC), describe demographic and clinical characteristics, and examine first tumor treatments associated with phenotype concordance. A total of 76,209 cases of female invasive breast cancer were identified in the California Cancer Registry from 1999 to 2004. Of those, 1,407 women who had not undergone a prophylactic mastectomy, had information on the status of three tumor markers, and were diagnosed with an SPBC during the study period were selected. SPBCs were significantly smaller, diagnosed at a higher stage and were node positive. Patients whose FPBC was ER(+)/-/PR(+)/-/HER2- and triple negative (TN) (ER-/PR-/HER2-), often had concordant phenotypes for their SPBC. ER(+)/-/PR(+)/-/HER2+ and HER2-positive (ER-/PR-/HER2+) FPBCs, often had discordant phenotypes for their SPBC. ER(+)/-/PR(+)/-/HER2- SPBCs often lacked HER2 expression and were ER and/or PR positive. Tumor laterality and synchronicity significantly predicted concordance as did having a FPBC whose phenotypes were ER(+)/-/PR(+)/-/HER2+, HER2-positive and TN, while first primary tumor treatment with chemotherapy predicted discordance. The relationship between multiple primary breast cancer phenotype concordance and patient prognosis has yet to be determined. Our results indicate that SPBC surveillance strategies include consideration of FPBC phenotype. Although our results are provocative, they may have been influenced by current criteria used to determine tumor independence.


Assuntos
Biomarcadores Tumorais/análise , Neoplasias da Mama/metabolismo , Segunda Neoplasia Primária/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/patologia , California , Feminino , Humanos , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Segunda Neoplasia Primária/patologia , Fenótipo , Receptor ErbB-2/metabolismo , Receptores de Estrogênio/metabolismo , Receptores de Progesterona/metabolismo , Sistema de Registros , Estudos Retrospectivos
16.
Malar J ; 9: 90, 2010 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-20377878

RESUMO

BACKGROUND: Nucleosome assembly proteins (NAPs) are histone chaperones that are crucial for the shuttling and incorporation of histones into nucleosomes. NAPs participate in the assembly and disassembly of nucleosomes thus contributing to chromatin structure organization. The human malaria parasite Plasmodium falciparum contains two nucleosome assembly proteins termed PfNapL and PfNapS. METHODS: Three-dimensional crystal structure of PfNapS has been determined and analysed. Gene knockout and localization studies were also performed on PfNapS using transfection studies. Fluorescence spectroscopy was performed to identify histone-binding sites on PfNapS. Extensive sequence and structural comparisons were done with the crystal structures available for NAP/SET family of proteins. RESULTS: Crystal structure of PfNapS shares structural similarity with previous structures from NAP/SET family. Failed attempts to knock-out the gene for PfNapS from malaria parasite suggest essentiality in the parasite. GFP-fused PfNapS fusion protein targeting indicates cellular localization of PfNapS in the parasite nucleus. Fluorescence spectroscopy data suggest that PfNapS interacts with core histones (tetramer, octamer, H3, H4, H2A and H2B) at a different site from its interaction with linker histone H1. This analysis illustrates two regions on the PfNapS dimer as the possible sites for histone recognition. CONCLUSIONS: This work presents a thorough analysis of the structural, functional and regulatory attributes of PfNapS from P. falciparum with respect to previously studied histone chaperones.


Assuntos
Chaperonas de Histonas/química , Histonas/metabolismo , Plasmodium falciparum/genética , Proteínas de Protozoários/química , Sequência de Aminoácidos , Sítios de Ligação/fisiologia , Montagem e Desmontagem da Cromatina/genética , Cristalografia por Raios X/métodos , Técnicas de Inativação de Genes , Chaperonas de Histonas/fisiologia , Humanos , Modelos Moleculares , Dados de Sequência Molecular , Nucleossomos/metabolismo , Filogenia , Plasmodium falciparum/metabolismo , Estrutura Terciária de Proteína , Proteínas de Protozoários/fisiologia , Homologia de Sequência de Aminoácidos , Espectrometria de Fluorescência
17.
Adv Mater ; 32(30): e1905366, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32548863

RESUMO

Intestinal organoids are useful in vitro models for basic and translational studies aimed at understanding and treating disease. However, their routine culture relies on animal-derived matrices that limit translation to clinical applications. In fact, there are few fully defined, synthetic hydrogel systems that allow for the expansion of intestinal organoids. Here, an allyl sulfide photodegradable hydrogel is presented, achieving rapid degradation through radical addition-fragmentation chain transfer (AFCT) reactions, to support routine passaging of intestinal organoids. Shear rheology to first characterize the effect of thiol and allyl sulfide crosslink structures on degradation kinetics is used. Irradiation with 365 nm light (5 mW cm-2 ) in the presence of a soluble thiol (glutathione at 15 × 10-3 m), and a photoinitiator (lithium phenyl-2,4,6-trimethylbenzoylphosphinate at 1 × 10-3 m), leads to complete hydrogel degradation in less than 15 s. Allyl sulfide hydrogels are used to support the formation of epithelial colonies from single intestinal stem cells, and rapid photodegradation is used to achieve repetitive passaging of stem cell colonies without loss in morphology or organoid formation potential. This platform could support long-term culture of intestinal organoids, potentially replacing the need for animal-derived matrices, while also allowing systematic variations to the hydrogel properties tailored for the organoid of interest.


Assuntos
Compostos Alílicos/química , Hidrogéis/química , Hidrogéis/metabolismo , Organoides/metabolismo , Fotólise , Compostos de Sulfidrila/química , Sulfetos/química , Animais , Mucosa Intestinal/citologia , Luz , Camundongos , Reologia , Resistência ao Cisalhamento , Solubilidade
18.
J Neurooncol ; 94(2): 249-61, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19340398

RESUMO

We examined the incidence of first primary central nervous system tumors (PCNST) in California from 2001-2005. This study period represents the first five years of data collection of benign PCNST by the California Cancer Registry. California's age-adjusted incidence rates (AAIR) for malignant and benign PCNST (5.5 and 8.5 per 100,000, respectively). Malignant PCNST were highest among non-Hispanic white males (7.8 per 100,000). Benign PCNST were highest among African American females (10.5 per 100,000). Hispanics, those with the lowest socioeconomic status, and those who lived in rural California were found to be significantly younger at diagnosis. Glioblastoma was the most frequent malignant histology, while meningioma had the highest incidence among benign histologies (2.6 and 4.5 per 100,000, respectively). This study is the first in the US to compare malignant to benign PCNST using a population-based data source. It illustrates the importance of PCNST surveillance in California and in diverse communities.


Assuntos
Neoplasias do Sistema Nervoso Central/epidemiologia , Glioblastoma/epidemiologia , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , California/epidemiologia , Neoplasias do Sistema Nervoso Central/etnologia , Criança , Pré-Escolar , Feminino , Glioblastoma/etnologia , Humanos , Incidência , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Fatores de Tempo , Adulto Jovem
19.
J Neurooncol ; 94(2): 263-73, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19340399

RESUMO

This study used data from the California Cancer Registry to comprehensively examine first primary central nervous system tumors (PCNST) by the International Classification of Childhood Cancers (ICCC) diagnostic groups and to compare their incidence by age groups, sex, race/ethnicity, socioeconomic status and tumor behavior. The study period, 2001-2005, represents the first 5 years of benign PCNST data collection in the state. The age-adjusted incidence rates were 2.1 for malignant and 1.3 for benign per 100,000. Children younger than 5 years old had the highest incidence of malignant PCNST (2.6 per 100,000). Teens aged 15-19 had the highest incidence of benign PCNST (1.8 per 100,000). Age-specific incidence rates were nearly the same for Hispanics, non-Hispanic whites, and Asian/Pacific Islanders for malignant PCNST among children younger than 5 (2.6-2.7 per 100,000); non-Hispanic whites had the highest rates in the 5-14 year-old age group (2.5 per 100,000) and Asian/Pacific Islanders the highest among the 15-19 year old age group (2.3 per 100,000). We found no statistically significant differences in the incidence of malignant PCNST by race/ethnicity in any age group. Astrocytoma had the highest incidence for both malignant and benign histology in most age groups.


Assuntos
Neoplasias do Sistema Nervoso Central/epidemiologia , Glioblastoma/epidemiologia , Adolescente , Adulto , Fatores Etários , California/epidemiologia , Neoplasias do Sistema Nervoso Central/etnologia , Criança , Pré-Escolar , Feminino , Glioblastoma/etnologia , Humanos , Incidência , Lactente , Recém-Nascido , Masculino , Fatores de Tempo , Adulto Jovem
20.
Breast J ; 15(6): 593-602, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19764994

RESUMO

Breast cancer research examining either molecular profiles or biomarker subtypes has focused on the estrogen receptor negative/progesterone receptor negative/human epidermal growth factor receptor 2 negative (ER-/PR-/HER2-) and ER-/PR-/HER2+ subtypes. Less is known about the epidemiology or clinical outcome of the other subtypes. This study examines the eight combinations of ER/PR/HER2 in patients with invasive breast cancer. The 5-year relative survival and the distribution among demographic, socioeconomic, and tumor characteristics of each of the subtypes are examined. Using the California Cancer Registry, 61,309 women with primary invasive breast cancer were classified according to ER/PR/HER2 status. Five-year relative survival was computed for the eight subtypes. Bivariate analyses were used to assess the distribution of cases across all subtypes. Multivariate logistic regression was used to compute the adjusted odds of having one of the five subtypes with the best and worst survival. Survival varied from 96% (ER+/PR+/HER2-) to 76% (ER-/PR-/HER2+ and ER-/PR-/HER2-). The four subtypes with the poorest survival were all ER negative. Women who were younger than age 50, non-Hispanic black or Hispanic, of the lowest SES groups, and had stage IV tumors that were undifferentiated were overrepresented in ER-/PR-/HER2+ and triple negative (ER-/PR-/HER2-) subtypes. Asian Pacific Islanders had increased odds (OR = 1.41; 95% confidence interval [CI] = 1.26-1.57) of having the ER-/PR-/HER2+ subtype. Stage III tumors (OR = 1.25; 95% CI = 1.08-1.44) and stage IV tumors (OR = 1.58; 95% CI = 1.27-1.98) had higher odds than stage I tumors of being ER-/PR-/HER2+. Stage IV tumors (OR = 0.54; 95% CI = 0.44-0.67) strongly decreased the odds of the ER-/PR-/HER2- subtype. Poorly differentiated and undifferentiated tumors were over 20 times as likely as well-differentiated tumors of being ER-/PR-/HER2- or ER-/PR-/HER2+. There are considerable differences in survival, demographics, and tumor characteristics among the eight subtypes. We recommend reporting breast cancer as an ER/PR/HER2 subtype and precisely documenting demographic and tumor characteristics.


Assuntos
Neoplasias da Mama/classificação , Receptor ErbB-2/análise , Receptores de Estrogênio/análise , Receptores de Progesterona/análise , Adulto , Idoso , Neoplasias da Mama/química , Neoplasias da Mama/mortalidade , Neoplasias da Mama/patologia , Feminino , Humanos , Pessoa de Meia-Idade , Análise Multivariada , Fatores Socioeconômicos , Fatores de Tempo
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