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1.
Midwifery ; 132: 103953, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38430791

RESUMO

PROBLEM: In the U.S., sudden unexpected infant deaths due to accidental suffocation and strangulation in bed are increasing. Though breastfeeding is a protective factor against sudden unexpected infant death, motivations to breastfeed often couple with unsafe infant sleep practices. Racial/ethnic disparities are present in sudden unexpected infant death, accidental suffocation and strangulation in bed, and breastfeeding. BACKGROUND: Promoting infant safe sleep and breastfeeding through community-level initiatives could address disparities in related outcomes. AIM: Investigate the relationship between community-level strategies and associated state-level outcomes for infant safe sleep and breastfeeding. METHODS: We employed an intervention mixed methods framework and exploratory sequential design. The qualitative component entailed a hermeneutical phenomenological framework to analyze key informant interview data from seven U.S. community-level providers participating in a practice improvement initiative. The quantitative component entailed descriptively analyzing infant safe sleep and breastfeeding indicators from the 2019 Pregnancy Risk Assessment Monitoring System and Ohio Pregnancy Assessment Survey. Qualitative and quantitative data were linked through embedded integration. FINDINGS: We identified two mixed insights: gaps in promotion and outcomes, and persistent disparities between infant safe sleep and breastfeeding promotion and outcomes. DISCUSSION: Our findings indicate conversational approaches could improve infant safe sleep and breastfeeding promotion, outcomes, and relative disparities. We find that community collaboration is needed to address organizational capacity limitations in promoting infant safe sleep and breastfeeding. CONCLUSION: Community-level organizations and providers should consider tailoring program offerings and care delivery to include conversational approaches and community collaboration to promote infant safe sleep and breastfeeding and decrease relative disparities in outcomes.


Assuntos
Aleitamento Materno , Promoção da Saúde , Morte Súbita do Lactente , Humanos , Aleitamento Materno/estatística & dados numéricos , Aleitamento Materno/métodos , Aleitamento Materno/psicologia , Feminino , Morte Súbita do Lactente/prevenção & controle , Promoção da Saúde/métodos , Promoção da Saúde/normas , Recém-Nascido , Adulto , Pesquisa Qualitativa , Lactente , Sono , Estados Unidos , Gravidez , Inquéritos e Questionários
2.
BMC Public Health ; 23(1): 437, 2023 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-36882767

RESUMO

BACKGROUND: In the U.S., sudden unexpected infant deaths (SUID) due to accidental suffocation and strangulation in bed (ASSB) are increasing, with disparities by race/ethnicity. While breastfeeding is a protective factor against infant mortality, racial/ethnic disparities are present in its uptake, and motivations to breastfeed are also often coupled with non-recommended infant sleep practices that are associated with infant sleep deaths. Combining infant safe sleep (ISS) and breastfeeding promotion on the community level presents opportunities to address racial/ethnic disparities and associated socioeconomic, cultural, and psychosocial influences. METHODS: We completed a descriptive qualitative hermeneutical phenomenology using thematic analysis of focus group data. We examined the phenomenon of community-level providers promoting ISS and breastfeeding in communities vulnerable to ISS and breastfeeding disparities. We asked eighteen informants participating in a national quality improvement collaborative about i.) areas requiring additional support to meet community needs around ISS and breastfeeding, and ii.) recommendations on tools to improve their work promoting ISS and breastfeeding. RESULTS: We identified four themes: i.) education and dissemination, ii.) relationship building and social support, iii.) working with clients' personal circumstances and considerations, and iv.) tools and systems. CONCLUSIONS: Our findings support embedding risk-mitigation approaches in ISS education; relationship building between providers, clients, and peers; and the provision of ISS and breastfeeding supportive material resources with educational opportunities. These findings may be used to inform community-level provider approaches to ISS and breastfeeding promotion.


Assuntos
Aleitamento Materno , Morte do Lactente , Humanos , Lactente , Feminino , Pesquisa Qualitativa , Escolaridade , Grupos Focais , Sono
3.
Nurs Womens Health ; 27(2): 90-102, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36803607

RESUMO

OBJECTIVE: To explore the phenomenon of clinicians' perceptions and experiences of promoting infant safe sleep (ISS) and breastfeeding during the COVID-19 pandemic. DESIGN: Descriptive qualitative hermeneutical phenomenology of key informant interviews conducted as part of a quality improvement initiative. SETTING: Maternity care services of 10 U.S. hospitals from April through September 2020. PARTICIPANTS: Ten hospital teams, including 29 clinicians. INTERVENTION: Participants were part of a national quality improvement intervention focused on promoting ISS and breastfeeding. Participants were asked about challenges and opportunities promoting ISS and breastfeeding during the pandemic. RESULTS: We identified four themes summarizing the experiences and perceptions of clinicians promoting ISS and breastfeeding in the COVID-19 pandemic: Strain on Clinicians Related to Hospital Policies, Coordination, and Capacity; Effects of Isolation for Parentsin Labor and Delivery; ReevaluatingOutpatient Follow-Up Care andSupport; and AdoptingShared Decision-Makingaround ISS andBreastfeeding. CONCLUSIONS: Our results support the need for physical and psychosocial care to reduce crisis-related burnout for clinicians to encourage the continued provision of ISS and breastfeeding education, particularly while navigating capacity constraints. Our findings also suggest that clinicians perceived that parents may require additional support to enhance potentially limited ISS and breastfeeding education. These findings may be used to inform approaches to parental and clinician maternity care support in future public health crises.


Assuntos
COVID-19 , Serviços de Saúde Materna , Lactente , Humanos , Feminino , Gravidez , Aleitamento Materno , Pandemias/prevenção & controle , Sono
5.
Pediatr Exerc Sci ; 31(2): 223-228, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30606067

RESUMO

Previous progressive aerobic cardiovascular endurance run (PACER) equations were developed to estimate peak oxygen consumption (VO2peak) from data collected during treadmill running. No equation has been developed using VO2peak assessed during the PACER. Purpose: To develop and validate a prediction equation to estimate VO2peak from the PACER in 10- to 15-year-olds. Methods: A sample of 163 youth were recruited to develop (n = 101) and validate (n = 62) a prediction equation. VO2peak was measured using a portable metabolic unit. Regression analysis yielded a prediction equation that included laps, body mass index, and interaction between sex and age. Correlations and repeated-measures analysis of variances were used to compare the measured and estimated VO2peak from the new Scott et al equation and 2 commonly used FitnessGram™ (Mahar et al 2011 and Mahar et al 2018) equations, and the impact of sex on predicted VO2peak. Results: Predicted VO2peak from the Mahar et al 2011 and 2018 equations was significantly lower compared with measured values, and the Scott et al prediction was not different. The Mahar et al 2018 equation tended to overestimate VO2peak in males but worked well for females. The Mahar et al 2011 and Scott et al equations revealed no sex differences. Conclusions: The Scott et al equation resulted in a more accurate estimate of VO2peak, performing equally well for both sexes.


Assuntos
Aptidão Cardiorrespiratória/fisiologia , Teste de Esforço/métodos , Consumo de Oxigênio/fisiologia , Corrida/fisiologia , Adolescente , Fatores Etários , Criança , Feminino , Voluntários Saudáveis , Humanos , Masculino , Fatores Sexuais
6.
Transfusion ; 58(3): 685-691, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29214630

RESUMO

BACKGROUND: The RhD blood group antigen is extremely polymorphic and the DEL phenotype represents one such class of polymorphisms. The DEL phenotype prevalent in East Asian populations arises from a synonymous substitution defined as RHD*1227A. However, initially, based on genomic and cDNA studies, the genetic basis for a DEL phenotype in Taiwan was attributed to a deletion of RHD Exon 9 that was never verified at the genomic level by any other independent group. Here we investigate the genetic basis for a Caucasian donor with a DEL partial D phenotype and compare the genomic findings to those initial molecular studies. STUDY DESIGN AND METHODS: The 3'-region of the RHD gene was amplified by long-range polymerase chain reaction (PCR) for massively parallel sequencing. Primers were designed to encompass a deletion, flanking Exon 9, by standard PCR for Sanger sequencing. Targeted sequencing of exons and flanking introns was also performed. RESULTS: Genomic DNA exhibited a 1012-bp deletion spanning from Intron 8, across Exon 9 into Intron 9. The deletion breakpoints occurred between two 25-bp repeat motifs flanking Exon 9 such that one repeat sequence remained. CONCLUSION: Deletion mutations bordered by repeat sequences are a hallmark of slipped-strand mispairing (SSM) event. We propose this genetic mechanism generated the germline deletion in the Caucasian donor. Extensive studies show that the RHD*1227A is the most prevalent DEL allele in East Asian populations and may have confounded the initial molecular studies. Review of the literature revealed that the SSM model explains some of the extreme polymorphisms observed in the clinically significant RhD blood group antigen.


Assuntos
Sequência de Bases , Éxons , Polimorfismo Genético , Sistema do Grupo Sanguíneo Rh-Hr/genética , Deleção de Sequência , Humanos , Taiwan
7.
Biochimie ; 116: 8-16, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26116885

RESUMO

Intracellular and extracellular functions of human galectin-1 are influenced by its redox surroundings due to the presence of six cysteines within its amino acid sequence. Galectin-1 recognises intracellular-membrane-anchored Ras proteins that act as molecular switches regulating multiple signal transduction pathways. Human tumours frequently express Ras proteins that have become continuously activated due to point mutations, and this typically leads to deregulation of tumour cell growth, angiogenesis and invasion of metastatic cancer cells. Of significance is that galectin-1 preferably recognises H-Ras, one of the human Ras isoforms, and in particular galectin-1 recognition of the H-Ras farnesyl moiety is paramount to H-Ras membrane anchorage, a prerequisite step for H-Ras-mediated signal transduction regulating normal cell growth and malignant transformation. Herein the impact of the redox state on galectin-1's ability to interact with farnesyl analogues is explored. We demonstrate for the first time that reduced galectin-1 directly binds farnesyl and does so in a carbohydrate-independent manner. A K28T mutation abolishes farnesyl recognition by reduced dimeric galectin-1 whilst its carbohydrate-binding activity is retained, thus demonstrating the presence of an independent region on galectin-1 pertaining to growth inhibitory activity. Intriguingly, oxidised galectin-1 also recognises farnesyl, the biological implication of this novel finding is yet to be elucidated. Further, the redox effect on galectin-1 extracellular function was investigated and we discover that oxidised galectin-1 demonstrates a protective effect upon acute lymphoblastic leukaemia cells challenged by oxidative stress.


Assuntos
Galectina 1/metabolismo , Linhagem Celular , Galectina 1/química , Galectina 1/genética , Humanos , Peróxido de Hidrogênio/metabolismo , Oxirredução , Mutação Puntual/genética , Estrutura Secundária de Proteína , Espécies Reativas de Oxigênio , Proteínas ras/genética , Proteínas ras/metabolismo
8.
J Phys Act Health ; 12(11): 1520-6, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25635408

RESUMO

BACKGROUND: It is unknown if activity monitors can detect the increased energy expenditure (EE) of wheelchair propulsion at different speeds or on different surfaces. METHODS: Individuals who used manual wheelchairs (n = 14) performed 5 wheeling activities: on a level surface at 3 speeds, on a rubberized track at 1 fixed speed and on a sidewalk course at a self-selected speed. EE was measured using a portable indirect calorimetry system and estimated by an Actical (AC) worn on the wrist and a SenseWear (SW) activity monitor worn on the upper arm. Repeated- measures ANOVA was used to compare measured EE to the estimates from the standard AC prediction equation and SW using 2 different equations. RESULTS: Repeated-measures ANOVA demonstrated a significant main effect between measured EE and estimated EE. There were no differences between the criterion method and the AC across the 5 activities. The SW overestimated EE when wheeling at 3 speeds on a level surface, and during sidewalk wheeling. The wheelchair-specific SW equation improved the EE prediction during low intensity activities, but error progressively increased during higher intensity activities. CONCLUSIONS: During manual wheelchair propulsion, the wrist-mounted AC provided valid estimates of EE, whereas the SW tended to overestimate EE.


Assuntos
Pessoas com Deficiência/estatística & dados numéricos , Metabolismo Energético , Atividade Motora , Cadeiras de Rodas , Acelerometria , Adolescente , Adulto , Idoso , Calorimetria Indireta , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
9.
Transfusion ; 54(11): 2931-40, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24894016

RESUMO

BACKGROUND: Red blood cells (RBCs) with D antigen levels only detected by anti-D adsorption-elution and an antiglobulin test express a DEL phenotype. For two DEL types, including RHD(1227G>A), immunization of D- recipients has been reported. This study's aim was to measure the prevalence of DEL-associated RHD alleles in a cohort of Australian D- donors to develop a model to estimate alloimmunization risk. STUDY DESIGN AND METHODS: D-, C+ and/or E+ blood donors were screened for RHD exons using quantitative polymerase chain reaction. Donors with RHD signals were DEL phenotyped with MCAD6 anti-D. RHD alleles were characterized via single-nucleotide polymorphism array or sequencing. Extended DEL phenotyping was performed with an anti-D panel. RESULTS: Among 2027 donors, 39 carried RHD alleles that have been previously reported to associate with either the DEL or the weak D phenotype. An additional five donors carried previously unreported RHD alleles and exhibited the DEL phenotype: RHD(IVS2-2delA), RHD(IVS1+5G>C), RHD(ex9:del/CE), and RHD(ex8:del/CE) represented twice. In total, DEL/weak D-associated RHD alleles were detected in 44 of 2027 donors or 2.17% (95% confidence interval, 1.54%-2.81%). The RHD(1227G>A) DEL allele was the most frequent (n = 16). The risk of transfusing D- females not more than 40 years of age with an RHD(1227G>A) DEL RBC unit (when managed as D-) is estimated to be one in 149,109 transfusions (range, 100,680-294,490). CONCLUSION: DEL/weak D-associated RHD alleles were found in 2.17% of Australian D-, C+ and/or E+ blood donors. This differs from previous European reports in that the clinically significant RHD(1227G>A) DEL allele is the most prevalent.


Assuntos
Alelos , Sequência de Bases , Doadores de Sangue , Modelos Genéticos , Mutação Puntual , Sistema do Grupo Sanguíneo Rh-Hr/genética , Deleção de Sequência , Adulto , Austrália , Incompatibilidade de Grupos Sanguíneos/genética , Incompatibilidade de Grupos Sanguíneos/prevenção & controle , Transfusão de Eritrócitos , Feminino , Frequência do Gene , Humanos , Masculino , Prevalência
10.
Br J Sports Med ; 48(13): 1048-53, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24825852

RESUMO

AIM: To examine the relationship between hand rim propulsion power and energy expenditure (EE) during wheelchair wheeling and to investigate whether adding other variables to the model could improve on the prediction of EE. METHODS: Individuals who use manual wheelchairs (n=14) performed five different wheeling activities in a wheelchair with a PowerTap power meter hub built into the right rear wheel. Activities included wheeling on a smooth, level surface at three different speeds (4.5, 5.5 and 6.5 km/h), wheeling on a rubberised track at one speed (5.5 km/h) and wheeling on a sidewalk course that included uphill and downhill segments at a self-selected speed. EE was measured using a portable indirect calorimetry system. Stepwise linear regression was performed to predict EE from power output variables. A repeated-measures analysis of variance was used to compare the measured EE to the estimates from the power models. Bland-Altman plots were used to assess the agreement between the criterion values and the predicted values. RESULTS: EE and power were significantly correlated (r=0.694, p<0.001). Regression analysis yielded three significant prediction models utilising measured power; measured power and speed; and measured power, speed and heart rate. No significant differences were found between measured EE and any of the prediction models. CONCLUSION: EE can be accurately and precisely estimated based on hand rim propulsion power. These results indicate that power could be used as a method to assess EE in individuals who use wheelchairs.


Assuntos
Metabolismo Energético/fisiologia , Exercício Físico/fisiologia , Mãos/fisiologia , Cadeiras de Rodas , Adulto , Fenômenos Biomecânicos/fisiologia , Calorimetria Indireta/instrumentação , Calorimetria Indireta/métodos , Desenho de Equipamento , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Monitorização Ambulatorial/instrumentação , Adulto Jovem
11.
Med Sci Sports Exerc ; 45(6): 1139-43, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23274606

RESUMO

PURPOSE: A graded exercise test (GXT) is the standard laboratory method of determining peak aerobic fitness (V˙O2peak). The FITNESSGRAM's Progressive Aerobic Cardiovascular Endurance Run (PACER) test is commonly used to estimate the peak oxygen consumption in the youth in the field.The objective of this study is to compare the peak physiological variables and RPEpeak during a treadmill GXT and the PACER test in 10- to 15-yr-old youths. METHODS: Participants (20 boys and 25 girls, 12.7 ± 1.7 yr) completed the PACER and treadmill GXT in a randomized order, separated by at least 24 h. HRpeak was measured via telemetry, V˙O2peak and RERpeak were measured using a portable metabolic system, and participants reported RPEpeak at the end of each test. RESULTS: No significant differences were found between the GXT and PACER HRpeak (197 vs 197 beats·min), RERpeak (1.13 vs 1.12), V˙O2peak (45.0 vs 45.9 mL·kg·min), and RPEpeak (8.4 vs 8.3). The SE of the measurement between the GXT V˙O2peak and PACER V˙O2peak was 1.4 mL·kg·min. CONCLUSIONS: It appears that the PACER elicits similar peak exercise responses compared with a treadmill GXT. The PACER can also be administered for fitness and functional capacity assessments in healthy and clinical populations.


Assuntos
Teste de Esforço/métodos , Adolescente , Criança , Feminino , Voluntários Saudáveis , Humanos , Masculino , Consumo de Oxigênio , Aptidão Física , Análise de Regressão , Corrida/fisiologia
12.
Angiogenesis ; 14(3): 293-307, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21523436

RESUMO

Cancer cells produce galectin-1 as a tumor promoting protein. Thiodigalactoside (TDG) as a non-metabolised small drug, is shown to suppress tumor growth by inhibiting multiple cancer enhancing activities of galectin-1, including immune cell dysregulation, angiogenesis and protection against oxidative stress. Thus, using B16F10 melanoma and 4T1 orthotopic breast cancer models, intratumoral injection of TDG significantly raised the levels of tumor-infiltrating CD8(+) lymphocytes and reduced CD31(+) endothelial cell content, reducing tumor growth. TDG treatment of tumors in Balb/c nude mice (defective in T cell immunity) reduced angiogenesis and slowed tumor growth by a third less than in immunocompetent mice. Knocking down galectin-1 expression (G1KD) in both cancer cell types significantly impeded tumor growth and the sensitivity of the G1KD tumors to TDG was severely reduced, highlighting a specific role for galectin-1. Endothelial cells were protected by galectin-1 from oxidative stress-induced apoptosis induced by H(2)O(2), but TDG inhibited this antioxidant protective effect of galectin-1 and reduced tube forming activity in angiogenic assays. We show for the first time that the single agent, TDG, concurrently prevents many tumor promoting effects of galectin-1 on angiogenesis, immune dysregulation and protection against oxidative stress, providing a potent and novel small molecule as an anti-cancer drug.


Assuntos
Antineoplásicos/farmacocinética , Galectina 1/antagonistas & inibidores , Imunidade Celular/efeitos dos fármacos , Neoplasias Experimentais/tratamento farmacológico , Neovascularização Patológica/tratamento farmacológico , Estresse Oxidativo/efeitos dos fármacos , Tiogalactosídeos/farmacologia , Animais , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Linfócitos T CD8-Positivos/patologia , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Resistencia a Medicamentos Antineoplásicos/imunologia , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Feminino , Galectina 1/genética , Galectina 1/imunologia , Galectina 1/metabolismo , Técnicas de Silenciamento de Genes , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Neoplasias Experimentais/genética , Neoplasias Experimentais/imunologia , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Neovascularização Patológica/genética , Neovascularização Patológica/imunologia , Neovascularização Patológica/metabolismo
13.
Acta Crystallogr Sect F Struct Biol Cryst Commun ; 66(Pt 12): 1647-51, 2010 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-21139216

RESUMO

Zebrafish (Danio rerio) are an important developmental and embryological model given the optical clarity of the embryos and larvae, which permits real-time viewing of developing pathologies. More recently, a broader scope for these vertebrates to model a range of human diseases, including some cancers, has been indicated. Zebrafish Drgal1-L2 has been identified as an orthologue of mammalian galectin-1, which is is a carbohydrate-binding protein that exhibits ß-galactoside-binding specificity and which is overexpressed by many aggressive human cancers. This study describes the cloning, expression in Escherichia coli, purification and crystallization of recombinant Drgal1-L2 protein in the presence of lactose (ligand). X-ray diffraction data from these novel crystals of zebrafish Drgal1-L2 were collected to a resolution of 1.5 Šusing a synchrotron-radiation source, enabling their characterization.


Assuntos
Galectinas/química , Proteínas de Peixe-Zebra/química , Peixe-Zebra/metabolismo , Animais , Cromatografia de Afinidade , Cromatografia em Gel , Cristalização , Cristalografia por Raios X , Eletroforese em Gel de Poliacrilamida , Humanos , Lactose/química
14.
Cancer Lett ; 299(2): 95-110, 2010 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-20826047

RESUMO

High level galectin-1 expression results in cancer cell evasion of the immune response, increased tumour survival and aggressive metastases. Using a galectin-1 polyclonal antibody, high levels of galectin-1 protein were shown to be expressed by breast cancer cells established from FVB/N MMTV-c-neu mice as well as by the B16F10 melanoma cell line. In mixed lymphocyte cultures using tumour cells as antigenic stimulators, addition of recombinant galectin-1 dose-dependently inhibited lymphocyte production. Disaccharides were identified that inhibited galectin-1 function and increased growth and activation of CD8(+) CTL's killing cancer cells. X-ray crystallographic structures of human galectin-1 in complex with inhibitory disaccharides revealed their mode of binding. Combining galectin-blocking carbohydrates as adjuvants with vaccine immunotherapy in vivo to promote immune responses significantly decreased tumour progression and improved the outcomes for tumour challenged mice. This is the first report showing that suitably selected galectin-1 blocking disaccharides will act as adjuvants promoting vaccine stimulated immune responses against tumours in vivo.


Assuntos
Dissacarídeos/farmacologia , Galectinas/metabolismo , Imunidade/efeitos dos fármacos , Neoplasias Mamárias Experimentais/imunologia , Animais , Western Blotting , Linfócitos T CD8-Positivos/imunologia , Vacinas Anticâncer/administração & dosagem , Vacinas Anticâncer/imunologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cristalografia por Raios X , Citotoxicidade Imunológica/efeitos dos fármacos , Dissacarídeos/química , Dissacarídeos/metabolismo , Feminino , Galectina 1/química , Galectina 1/genética , Galectina 1/metabolismo , Galectina 3/química , Galectina 3/genética , Galectina 3/metabolismo , Galectinas/química , Galectinas/genética , Humanos , Imunoterapia/métodos , Neoplasias Mamárias Experimentais/patologia , Neoplasias Mamárias Experimentais/terapia , Camundongos , Camundongos Endogâmicos , Modelos Moleculares , Ligação Proteica , Tiogalactosídeos/química , Tiogalactosídeos/metabolismo , Tiogalactosídeos/farmacologia , Carga Tumoral/efeitos dos fármacos
15.
Protein Pept Lett ; 16(10): 1249-55, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19860718

RESUMO

Oxidized human galectin-1 plays a role in the immune response to injured axons. Over-expression of galectin-1 by cancer, in combination with cancer associated oxidative stress suggests oxidized human galectin-1 may also play a role(s) in tumourigenesis. Here we generate milligram quantities of oxidized human galectin-1 and undertake biophysical characterization. The protein adopts a number of different states. Two separable oxidized forms are identified that exist as largely mono-disperse solutions at higher milligram/ml concentrations. The presence of disulphide bonds is confirmed for these two protein forms, as is their change in overall shape and loss of lectin activity. Our studies lead to production of a particular mono-disperse oxidized human galectin-1 species that is anticipated most optimal for investigations requiring milligram/ml concentrations such as X-ray crystallography.


Assuntos
Galectina 1/biossíntese , Proteínas Recombinantes/biossíntese , Cromatografia em Gel , Dissulfetos/química , Eletroforese em Gel de Poliacrilamida , Galectina 1/química , Galectina 1/genética , Humanos , Oxirredução , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , Solubilidade
16.
Acta Crystallogr Sect F Struct Biol Cryst Commun ; 63(Pt 11): 967-71, 2007 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-18007053

RESUMO

Galectin-1 is considered to be a regulator protein as it is ubiquitously expressed throughout the adult body and is responsible for a broad range of cellular regulatory functions. Interest in galectin-1 from a drug-design perspective is founded on evidence of its overexpression by many cancers and its immunomodulatory properties. The development of galectin-1-specific inhibitors is a rational approach to the fight against cancer because although galectin-1 induces a plethora of effects, null mice appear normal. X-ray crystallographic structure determination will aid the structure-based design of galectin-1 inhibitors. Here, the crystallization and preliminary diffraction analysis of human galectin-1 crystals generated under six different conditions is reported. X-ray diffraction data enabled the assignment of unit-cell parameters for crystals grown under two conditions, one belongs to a tetragonal crystal system and the other was determined as monoclinic P2(1), representing two new crystal forms of human galectin-1.


Assuntos
Galectina 1/química , Cristalização , Cristalografia por Raios X , Eletroforese em Gel de Poliacrilamida , Humanos , Luz , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , Espalhamento de Radiação
17.
Artigo em Inglês | MEDLINE | ID: mdl-16511112

RESUMO

Rotavirus recognition and attachment to host cells involves interaction with the spike protein VP4 that projects outwards from the surface of the virus particle. An integral component of these spikes is the VP8* domain, which is implicated in the direct recognition and binding of sialic acid-containing cell-surface carbohydrates and facilitates subsequent invasion by the virus. The expression, purification, crystallization and preliminary X-ray diffraction analysis of VP8* from porcine CRW-8 rotavirus is reported. Diffraction data have been collected to 2.3 A resolution, enabling the determination of the VP8* structure by molecular replacement.


Assuntos
Proteínas de Ligação a RNA/química , Rotavirus/química , Proteínas não Estruturais Virais/química , Animais , Sítios de Ligação , Cristalização/métodos , Ácido N-Acetilneuramínico , Reação em Cadeia da Polimerase , Suínos , Proteínas Virais/química , Proteínas Virais/genética , Proteínas Virais/isolamento & purificação , Difração de Raios X
18.
Acta Crystallogr Sect F Struct Biol Cryst Commun ; 61(Pt 11): 989-93, 2005 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-16511215

RESUMO

Rotaviruses exhibit host-specificity and the first crystallographic information on a rotavirus strain that infects humans is reported here. Recognition and attachment to host cells, leading to invasion and infection, is critically linked to the function of the outer capsid spike protein of the rotavirus particle. In some strains the VP8* component of the spike protein is implicated in recognition and binding of sialic-acid-containing cell-surface carbohydrates, thereby enabling infection by the virus. The cloning, expression, purification, crystallization and initial X-ray diffraction analysis of the VP8* core from human Wa rotavirus is reported. Two crystal forms (trigonal P3(2)21 and monoclinic P2(1)) have been obtained and X-ray diffraction data have been collected, enabling determination of the VP8*(64-223) structure by molecular replacement.


Assuntos
Carboidratos/química , Proteínas de Ligação a RNA/química , Proteínas de Ligação a RNA/genética , Rotavirus/genética , Proteínas não Estruturais Virais/química , Proteínas não Estruturais Virais/genética , Membrana Celular/metabolismo , Clonagem Molecular , Cristalização , Primers do DNA/química , Eletroforese em Gel de Poliacrilamida , Escherichia coli/metabolismo , Ácido N-Acetilneuramínico/química , Ligação Proteica , RNA Viral/química , Difração de Raios X
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