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1.
Diabet Med ; 37(12): 2116-2123, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32510602

RESUMO

AIMS: To estimate the rate at which people with diabetes and a low risk of foot ulceration change diabetic foot ulceration risk status over time, and to estimate the rate of ulceration, amputation and death among this population. METHODS: We conducted an observational study of 10 421 people with diabetes attending foot screening in an outpatient setting in NHS Fife, UK, using routinely collected data from a national diabetes register, NHS SCI Diabetes. We estimated the proportion of people who changed risk status and the cumulative incidence of ulceration, amputation and death, respectively, among people with diabetes at low risk of diabetic foot ulceration at 2-year follow-up. RESULTS: At 2-year follow-up, 5.1% (95% CI 4.7, 5.6) of people with diabetes classified as low risk at their first visit had progressed to moderate risk. The cumulative incidence of ulceration, amputation and death was 0.4% (95% CI 0.3, 0.6), 0.1% (95% CI 0.1, 0.2) and 3.4% (95% CI 3.1, 3.8), respectively. CONCLUSIONS: At 2-year follow-up, 5% of people at low risk of diabetic foot ulceration changed clinical risk status and <1% of people experienced foot ulceration or amputation. These findings provide information which will help to inform the current debate regarding optimal foot screening intervals.


Assuntos
Amputação Cirúrgica/estatística & dados numéricos , Diabetes Mellitus/epidemiologia , Pé Diabético/epidemiologia , Mortalidade , Idoso , Feminino , Humanos , Masculino , Programas de Rastreamento/métodos , Pessoa de Meia-Idade , Guias de Prática Clínica como Assunto , Medição de Risco , Reino Unido/epidemiologia
2.
Transgenic Res ; 29(4): 443-459, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32613547

RESUMO

At LFB USA, Inc., the ultimate use for transgenic cloned goats is for the production of recombinant human protein therapeutics in their milk. This retrospective analysis of the Somatic Cell Nuclear Transfer (SCNT) program, spanning from 1998 to 2010, examined parameters potentially affecting the outcomes and efficiencies in this commercial operation. Over 37,000 + ova were utilized in the SCNT protocol producing a total of 203 cloned goats. Fifty one (51) clones were produced from non-transfected (transgenic and non-transgenic animal donor) cell lines and 152 clones were produced from transfected cell lines. Comparisons and summaries of (a) transfected versus non-transfected cell lines, (b) relationship of SCNT parameters to offspring produced, (c) skin versus fetal cells, (d) fresh versus cryopreserved cells, (e) parameters from all cell lines used versus those producing SCNT offspring, (f) variation among cell sources, (g) methods of SCNT parturition management and effects on live offspring, and lastly (h) SCNT variation by program are reported. Findings indicate that (a) non-transfected cell lines were more efficient versus transfected cell lines in generating viable cloned offspring on a per reconstructed embryo transferred basis, (b) transfected fetal fibroblasts had improved efficiency versus transfected skin fibroblasts, (c) the percentage of non-transfected cell lines that produced offspring was statistically higher than transfected cell lines, (d) and induction of parturition improved the percentage of viable offspring. In summary, this retrospective analysis on the SCNT process has identified certain parameters for improved efficiency in producing viable cloned goats in a commercial setting.


Assuntos
Criação de Animais Domésticos/métodos , Animais Geneticamente Modificados/genética , Blastocisto/citologia , Transferência Embrionária/veterinária , Embrião de Mamíferos/citologia , Feto/citologia , Técnicas de Transferência Nuclear/estatística & dados numéricos , Animais , Clonagem de Organismos , Comércio , Cabras , Estudos Retrospectivos
3.
Transfus Med ; 29 Suppl 1: 42-51, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29767450

RESUMO

OBJECTIVES: To evaluate the cost-effectiveness of changing opening times, introducing a donor health report and reducing the minimum inter-donation interval for donors attending static centres. BACKGROUND: Evidence is required about the effect of changes to the blood collection service on costs and the frequency of donation. METHODS/MATERIALS: This study estimated the effect of changes to the blood collection service in England on the annual number of whole-blood donations by current donors. We used donors' responses to a stated preference survey, donor registry data on donation frequency and deferral rates from the INTERVAL trial. Costs measured were those anticipated to differ between strategies. We reported the cost per additional unit of blood collected for each strategy versus current practice. Strategies with a cost per additional unit of whole blood less than £30 (an estimate of the current cost of collection) were judged likely to be cost-effective. RESULTS: In static donor centres, extending opening times to evenings and weekends provided an additional unit of whole blood at a cost of £23 and £29, respectively. Introducing a health report cost £130 per additional unit of blood collected. Although the strategy of reducing the minimum inter-donation interval had the lowest cost per additional unit of blood collected (£10), this increased the rate of deferrals due to low haemoglobin (Hb). CONCLUSION: The introduction of a donor health report is unlikely to provide a sufficient increase in donation frequency to justify the additional costs. A more cost-effective change is to extend opening hours for blood collection at static centres.


Assuntos
Doadores de Sangue , Seleção do Doador/economia , Adolescente , Adulto , Análise Custo-Benefício , Inglaterra , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
4.
Transgenic Res ; 27(1): 115-122, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29249046

RESUMO

Production of transgenic founder goats involves introducing and stably integrating an engineered piece of DNA into the genome of the animal. At LFB USA, the ultimate use of these transgenic goats is for the production of recombinant human protein therapeutics in the milk of these dairy animals. The transgene or construct typically links a milk protein specific promoter sequence, the coding sequence for the gene of interest, and the necessary downstream regulatory sequences thereby directing expression of the recombinant protein in the milk during the lactation period. Over the time period indicated (1995-2012), pronuclear microinjection was used in a number of programs to insert transgenes into 18,120, 1- or 2- cell stage fertilized embryos. These embryos were transferred into 4180 synchronized recipient females with 1934 (47%) recipients becoming pregnant, 2594 offspring generated, and a 109 (4.2%) of those offspring determined to be transgenic. Even with new and improving genome editing tools now available, pronuclear microinjection is still the predominant and proven technology used in this commercial setting supporting regulatory filings and market authorizations when producing founder transgenic animals with large transgenes (> 10 kb) such as those necessary for directing monoclonal antibody production in milk.


Assuntos
Animais Geneticamente Modificados , Engenharia Genética/estatística & dados numéricos , Cabras/genética , Animais , Técnicas de Cultura Embrionária , Feminino , Engenharia Genética/métodos , Cabras/embriologia , Masculino , Microinjeções , Gravidez , Taxa de Gravidez , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Estudos Retrospectivos
5.
Soft Matter ; 12(1): 255-62, 2016 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-26457973

RESUMO

The ability to design and implement silk feedstock formulations for tailored spinning has so far eluded the bioengineers. Recently, the high throughput screening technique of differential scanning fluorimetry (DSF) demonstrated the link between the instability transition temperature (Ti) and the processability of the silk feedstock. Using DSF we screened a large set of chemicals known to affect solvent quality. A multivariate analysis of the results shows that, regardless of the diversity of chemicals, three groupings are significantly distinguishable: G1 = similar to native silk; G2 = largely dominated by electrostatic interactions; and G3 = dominated by chelating interactions. We propose a thermodynamic analysis based on a pre- and post-transition fit to estimate the van't Hoff enthalpies (ΔHv) and the instability temperature (Ti). Our analysis shows that the ΔTi and ΔHv values were distinct: G1 (ΔTi = 0.23 ± 0.2; ΔHv = -159.1 ± 5.6 kcal mol(-1)), G2 (ΔTi = -7.3 ± 0.7; ΔHv = -191.4 ± 5.5 kcal mol(-1)), and G3 (ΔTi = -19.9 ± 3.3; ΔHv = -68.8 ± 6.0 kcal mol(-1)). Our analysis further combined the ΔTi value and the ΔHv value using stability ΔΔG to find that G1 only marginally stabilizes native silks (ΔΔG = -0.15 ± 0.04 kcal mol(-1)), whereas G2 and G3 destabilize native silk (ΔΔG = 3.8 ± 0.11 and ΔΔG = 3.8 ± 0.3 kcal mol(-1), respectively). Here our analysis shows that native silk has a complex multistep transition that is possibly non-cooperative. However, all three groupings also show a direct and cooperative transition with varied stabilization effects. This analysis suggests that native silks are able to sample multiple substates prior to undergoing (or to delay) the final transition. We conclude by hypothesizing that the observed energetic plasticity may be mediated by a fragile packaging of the silk tertiary structure that is readily lost when the solvent quality changes.


Assuntos
Seda/química , Temperatura de Transição , Quelantes/química , Fluorometria , Conformação Proteica , Estabilidade Proteica , Eletricidade Estática , Indústria Têxtil/normas
6.
Br J Cancer ; 110(6): 1606-13, 2014 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-24548858

RESUMO

BACKGROUND: RAD21 is a component of the cohesion complex and is integral to chromosome segregation and error-free DNA repair. RAD21 is functionally important in tumour progression but its role in colorectal carcinoma (CRC) is unclear. We therefore assessed its clinicopathological and prognostic significance in CRC, as well as its effect on chemosensitivity. METHODS: A retrospective observation study examined RAD21 expression in 652 CRCs using a tissue microarray approach. Correlation with clinicopathological factors including gender, tumour grade, mucinous subtype, TNM stage, disease-specific survival (DSS), BRAF and KRAS mutation status, tumour p53 immunostaining, tumour microsatellite instability and tumour CpG island methylator phenotype was performed. Colorectal cancer cell clones with stable RAD21 knockdown were generated and tested for cellular sensitivity to conventional chemotherapeutic drugs. RESULTS: RAD21 expression was significantly correlated with male gender (56.7% vs 43.3%, P=0.02), well-differentiated histology (14.4% vs 4.0%, P=0.0001), higher T-stage (36.1% vs 27.0%, P=0.01), presence of metastasis (18.8% vs 12.6%, P=0.03), and shorter DSS (hazard ratio (HR) 1.4, 95% CI 1.1 to 1.9, P=0.01) in both univariate and multivariate analysis. RAD21 expression was associated with shorter DSS in patients with KRAS mutant tumours (HR:2.6, 95% CI:1.4-4.3, P=0.001) and in patients receiving adjuvant chemoradiotherapy (HR:1.9, 95% CI:1.2-3.0, P=0.008). Colorectal cancer cells with RAD21 knockdown exhibited enhanced sensitivity to 5-fluorouracil, either alone or in combination with oxaliplatin. CONCLUSIONS: RAD21 expression in CRC is associated with aggressive disease especially in KRAS mutant tumours and resistance to chemoradiotherapy. RAD21 may be an important novel therapeutic target.


Assuntos
Biomarcadores Tumorais/biossíntese , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Mutação , Proteínas Nucleares/biossíntese , Fosfoproteínas/biossíntese , Proteínas Proto-Oncogênicas/genética , Proteínas ras/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/genética , Proteínas de Ciclo Celular , Neoplasias Colorretais/patologia , Proteínas de Ligação a DNA , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Proteínas Nucleares/genética , Fosfoproteínas/genética , Prognóstico , Proteínas Proto-Oncogênicas p21(ras) , Estudos Retrospectivos , Fatores Sexuais , Análise Serial de Tecidos
7.
Diabetes Obes Metab ; 16(5): 433-42, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24237939

RESUMO

AIMS: Indirect evidence from randomized controlled trials (RCTs) was used to estimate the effect of dapagliflozin, a new agent with a novel mechanism of action (SGLT-2 inhibition), relative to other anti-diabetes therapies after 1 year of treatment. METHODS: A systematic literature review and Bayesian network meta-analysis (NMA) of RCTs involving anti-diabetes treatments added to metformin were conducted. RCTs enrolling subjects with type 2 diabetes inadequately controlled on metformin monotherapy were included. Comparators included dipeptidyl peptidase-4 (DPP-4) inhibitors, thiazolidinediones (TZDs), sulphonylureas, glucagon-like peptide-1 (GLP-1) analogues and dapagliflozin. Outcomes of interest were mean change from baseline HbA1c, weight and systolic blood pressure, and incidence of hypoglycaemia. RESULTS: From 4270 abstracts, six RCTs were included in the primary analysis; no RCTs involving GLP-1 analogues met primary inclusion criteria. All RCTs were actively controlled with sulphonylureas. The mean change in HbA1c from baseline was similar across comparators. The treatment effect (95% credible interval) of dapagliflozin on HbA1c was -0.08% (-0.25, 0.10) relative to DPP-4 inhibitors, -0.02% (-0.24, 0.21) relative to TZDs and 0.00% (-0.16, 0.16) relative to sulphonylureas. Non-sulphonylureas showed significantly lower risk of hypoglycaemia relative to sulphonylureas. Dapagliflozin had a significant effect on weight change: the relative difference was -2.74 kg (-5.35, -0.10) compared with DPP-4 inhibitors, and -4.67 kg (-7.03, -2.35) compared with sulphonylureas. Systolic blood pressure was not meta-analysed due to infrequent reporting. CONCLUSION: Compared with DPP-4 inhibitors, TZDs and sulphonylureas, dapagliflozin offers similar HbA1c control after 1 year, with similar or reduced risk of hypoglycaemia and the additional benefit of weight loss, when added to metformin.


Assuntos
Compostos Benzidrílicos/administração & dosagem , Diabetes Mellitus Tipo 2/tratamento farmacológico , Glucosídeos/administração & dosagem , Hipoglicemia/induzido quimicamente , Hipoglicemiantes/administração & dosagem , Metformina/administração & dosagem , Compostos de Sulfonilureia/administração & dosagem , Administração Oral , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Peso Corporal/efeitos dos fármacos , Diabetes Mellitus Tipo 2/sangue , Inibidores da Dipeptidil Peptidase IV/administração & dosagem , Quimioterapia Combinada , Feminino , Hemoglobinas Glicadas/efeitos dos fármacos , Hemoglobinas Glicadas/metabolismo , Humanos , Hipoglicemia/sangue , Masculino , Pessoa de Meia-Idade , Ensaios Clínicos Controlados Aleatórios como Assunto , Tiazolidinedionas/administração & dosagem , Resultado do Tratamento
8.
Int J Clin Pract ; 68(10): 1181-9, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25269948

RESUMO

The aim of this study was to develop a user-friendly checklist for critical appraisal of indirect comparisons of drugs, considering clinical, methodological/statistical and quality aspects, mainly to be applied in drug evaluation in the decision-making context. After conducting a review of the literature, we used group consensus to establish the key points of the checklist, focusing mainly on indirect comparisons, but including topics related to network meta-analysis or multiple treatment comparisons. The coordinating group elaborated the first draft, which was reviewed by external experts, re-evaluated by the coordinating group and finally assessed by 23 drug evaluation experts trained in indirect comparisons, who applied the checklist to one study. The Kappa index of agreement was calculated and the final checklist was developed by group consensus including the external experts. The checklist has two parts. The first consists of three eliminatory key questions while the second includes 17 items: 5 regarding quality, 5 regarding clinical issues and 7 dealing with methodology/statistics. The median kappa values of the 23 evaluations were 0.83 (range 0.67-0.93), 0.61 (0.54-0.91) and 0.36 (0.22-1) with regard to quality, clinical aspects and methodology/statistics, respectively. A structured checklist was developed to facilitate critical appraisal of key issues in indirect comparisons, including comments for assessing the consequences of its application to drug evaluation in the decision-making context. Agreement between reviewers in clinical and quality items was good, but weaker in methodology/statistics ones.


Assuntos
Benchmarking , Lista de Checagem , Técnicas de Apoio para a Decisão , Medicina Baseada em Evidências/métodos , Medicina Baseada em Evidências/normas , Humanos
9.
J Mol Biol ; 436(4): 168415, 2024 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-38135177

RESUMO

Staphylococcus aureus is an important human pathogen, and the prevalence of antibiotic resistance is a major public health concern. The evolution of pathogenicity and resistance in S. aureus often involves acquisition of mobile genetic elements (MGEs). Bacteriophages play an especially important role, since transduction represents the main mechanism for horizontal gene transfer. S. aureus pathogenicity islands (SaPIs), including SaPI1, are MGEs that carry genes encoding virulence factors, and are mobilized at high frequency through interactions with specific "helper" bacteriophages, such as 80α, leading to packaging of the SaPI genomes into virions made from structural proteins supplied by the helper. Among these structural proteins is the portal protein, which forms a ring-like portal at a fivefold vertex of the capsid, through which the DNA is packaged during virion assembly and ejected upon infection of the host. We have used high-resolution cryo-electron microscopy to determine structures of the S. aureus bacteriophage 80α portal itself, produced by overexpression, and in situ in the empty and full SaPI1 virions, and show how the portal interacts with the capsid. These structures provide a basis for understanding portal and capsid assembly and the conformational changes that occur upon DNA packaging and ejection.


Assuntos
Ilhas Genômicas , Fagos de Staphylococcus , Staphylococcus aureus , Humanos , Proteínas do Capsídeo/química , Microscopia Crioeletrônica , Staphylococcus aureus/genética , Staphylococcus aureus/patogenicidade , Staphylococcus aureus/virologia , Fagos de Staphylococcus/genética , Fatores de Virulência/genética , Transdução Genética , Empacotamento do DNA , Conformação de Ácido Nucleico
10.
Prev Med ; 57(5): 419-25, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23628517

RESUMO

OBJECTIVE: Cervical cancer screening using the human papillomavirus (HPV) test and Pap test together (co-testing) is an option for average-risk women ≥ 30 years of age. With normal co-test results, screening intervals can be extended. The study objective is to assess primary care provider practices, beliefs, facilitators and barriers to using the co-test and extending screening intervals among low-income women. METHOD: Data were collected from 98 providers in 15 Federally Qualified Health Center (FQHC) clinics in Illinois between August 2009 and March 2010 using a cross-sectional survey. RESULTS: 39% of providers reported using the co-test, and 25% would recommend a three-year screening interval for women with normal co-test results. Providers perceived greater encouragement for co-testing than for extending screening intervals with a normal co-test result. Barriers to extending screening intervals included concerns about patients not returning annually for other screening tests (77%), patient concerns about missing cancer (62%), and liability (52%). CONCLUSION: Among FQHC providers in Illinois, few administered the co-test for screening and recommended appropriate intervals, possibly due to concerns over loss to follow-up and liability. Education regarding harms of too-frequent screening and false positives may be necessary to balance barriers to extending screening intervals.


Assuntos
Atitude do Pessoal de Saúde , Cultura , Detecção Precoce de Câncer/estatística & dados numéricos , Infecções por Papillomavirus/prevenção & controle , Atenção Primária à Saúde/estatística & dados numéricos , Neoplasias do Colo do Útero/prevenção & controle , Esfregaço Vaginal/estatística & dados numéricos , Adulto , Estudos Transversais , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Mau Uso de Serviços de Saúde/estatística & dados numéricos , Pesquisa sobre Serviços de Saúde , Hospitais Federais/estatística & dados numéricos , Humanos , Illinois , Padrões de Prática Médica/estatística & dados numéricos , Estados Unidos , Revisão da Utilização de Recursos de Saúde
11.
bioRxiv ; 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37786723

RESUMO

Staphylococcus aureus is an important human pathogen, and the prevalence of antibiotic resistance is a major public health concern. The evolution of pathogenicity and resistance in S. aureus often involves acquisition of mobile genetic elements (MGEs). Bacteriophages play an especially important role, since transduction represents the main mechanism for horizontal gene transfer. S. aureus pathogenicity islands (SaPIs), including SaPI1, are MGEs that carry genes encoding virulence factors, and are mobilized at high frequency through interactions with specific "helper" bacteriophages, such as 80α, leading to packaging of the SaPI genomes into virions made from structural proteins supplied by the helper. Among these structural proteins is the portal protein, which forms a ring-like portal at a fivefold vertex of the capsid, through which the DNA is packaged during virion assembly and ejected upon infection of the host. We have used high-resolution cryo-electron microscopy to determine structures of the S. aureus bacteriophage 80α portal in solution and in situ in the empty and full SaPI1 virions, and show how the portal interacts with the capsid. These structures provide a basis for understanding portal and capsid assembly and the conformational changes that occur upon DNA packaging and ejection.

12.
Br J Dermatol ; 166(1): 179-88, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21910698

RESUMO

BACKGROUND: Ustekinumab, a novel monoclonal antibody for the treatment of moderate to severe plaque-type psoriasis, has recently received regulatory approval in Europe, bringing the total number of biologic agents licensed in this indication to five. To assist treatment selection in daily practice it is essential to understand the benefit/risk profile of these agents and in the absence of a clinical trial comparing all available biologics a number of reviews have used statistical techniques to generate estimates of the comparative effectiveness of these therapies through the available network of randomized clinical trials. These estimates have previously been published for a limited range of psoriasis biologic treatments, although, to date no review has compared all the currently available agents in Europe. OBJECTIVES: To estimate the comparative effectiveness of all biologic agents indicated in the treatment of moderate to severe psoriasis currently available in Europe based on the primary trial endpoints. METHODS: A number of databases were searched for details of randomized controlled trials of available biologics in the treatment of plaque-type psoriasis in adults. Comparative effectiveness was estimated based on the reported Psoriasis Area and Severity Index (PASI) 50, 75 and 90 response rates. A network meta-analysis conducted on the ordered probit scale and implemented as a Bayesian hierarchical model provided estimates for the probability of response and relative risk vs. placebo, based on all observed comparisons. RESULTS: Twenty trials were included in the meta-analysis including patients with a mean disease duration of 18-22years. Based on the indirect comparison and given a placebo PASI 50 response of 13%, infliximab had the highest predicted mean probability of response at PASI levels 50 (93%), 75 (80%) and 90 (54%), followed by ustekinumab 90 mg at 90%, 74% and 46%, respectively, and then ustekinumab 45mg, adalimumab, etanercept and efalizumab. CONCLUSIONS: The ordered probit model allowed a quantitative comparison of all currently licensed biologics, providing estimates on comparative effectiveness and a suggested ranking of treatments that is of potential use to decision-makers. However, the analysis is based on indirect comparisons of the primary endpoint reported from short-term randomized trials.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Produtos Biológicos/uso terapêutico , Fármacos Dermatológicos/uso terapêutico , Psoríase/tratamento farmacológico , Adalimumab , Adulto , Anticorpos Monoclonais Humanizados/uso terapêutico , Etanercepte , Feminino , Humanos , Imunoglobulina G/uso terapêutico , Infliximab , Masculino , Pessoa de Meia-Idade , Ensaios Clínicos Controlados Aleatórios como Assunto , Receptores do Fator de Necrose Tumoral/uso terapêutico , Resultado do Tratamento , Ustekinumab
13.
MethodsX ; 9: 101831, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36117678

RESUMO

Rubbers are ubiquitous in engineering applications where they are often subjected to loading leading to high strain rate deformation. The strong rate and temperature dependence of rubbers and their composites motivates research into understanding their mechanical response under a wide range of conditions. However, experimental characterisation of the rate-temperature dependence of soft rubbers is challenging. In this methods paper, an improved methodology is proposed for conducting Dynamic Mechanical Analysis (DMA) experiments on rubbers. The higher quality data produced can be used in time-temperature superposition (TTS) applications to derive a more accurate definition of the rubber's rate-temperature dependence. Overall, the improvements obtained can be summarised as follows:•Overall, the proposed methodology can be summarised with the following improvements:•Reducing clamping artefacts due to volume expansion•Ensuring high quality temperature stability•Improving the contact area between the specimen and the clamps.

14.
Sci Adv ; 8(48): eade0459, 2022 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-36449623

RESUMO

Staphylococcus epidermidis is an opportunistic pathogen of the human skin, often associated with infections of implanted medical devices. Staphylococcal picoviruses are a group of strictly lytic, short-tailed bacteriophages with compact genomes that are attractive candidates for therapeutic use. Here, we report the structure of the complete virion of S. epidermidis-infecting phage Andhra, determined using high-resolution cryo-electron microscopy, allowing atomic modeling of 11 capsid and tail proteins. The capsid is a T = 4 icosahedron containing a unique stabilizing capsid lining protein. The tail includes 12 trimers of a unique receptor binding protein (RBP), a lytic protein that also serves to anchor the RBPs to the tail stem, and a hexameric tail knob that acts as a gatekeeper for DNA ejection. Using structure prediction with AlphaFold, we identified the two proteins that comprise the tail tip heterooctamer. Our findings elucidate critical features for virion assembly, host recognition, and penetration.


Assuntos
Especificidade de Hospedeiro , Fagos de Staphylococcus , Humanos , Staphylococcus epidermidis , Microscopia Crioeletrônica , Capsídeo , Proteínas do Capsídeo
15.
Calcif Tissue Int ; 89(2): 140-50, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21633782

RESUMO

Elevated serum levels of the phosphate-regulating hormone fibroblast growth factor 23 (FGF23) are found in patients with phosphate wasting diseases and chronic kidney disease-mineral and bone disorder (CKD-MBD). These diseases are associated with rickets and renal osteodystrophy, respectively. FGF23 is secreted from osteoblastic cells and signals through FGFRs, membrane coreceptor alpha-Klotho (Klotho), and, possibly, a circulating form of Klotho. Despite the absence of detectable Klotho on osteoblastic cells, studies have suggested that forced FGF23 expression in osteoblasts inhibited mineralization. Thus, we examined the effects of exogenously applied FGF23 on osteoblastic MC3T3.E1 cell proliferation and differentiation, with and without soluble Klotho. MC3T3.E1 cells were cultured in osteoblast differentiation medium, supplemented with FGF23 (0.1-1,000 ng/mL), Klotho (50 ng/mL), the combination FGF23 + Klotho, and FGF2 (100 ng/mL) as a control. Neither FGF23 nor Klotho exposure affected proliferation of day 4 growth phase cells or mineralization of day 14 cultures. In contrast, FGF23 + Klotho resulted in inhibition of mineralization and osteoblast activity markers at day 14, and a slight, reproducible induction of proliferation. Inhibition of FGFR1, but not FGFR2 or FGFR3, completely restored FGF23 + Klotho-induced inhibition of alkaline phosphatase (ALP) activity at day 7. ALP activity was partially restored by the MAPK inhibitor U0126 but not inhibitors p38 and P13K. Thus, soluble Klotho enables FGF23 signaling in MC3T3.E1 cells, likely through FGFR 1(IIIc). Elevated FGF23 actions, in part, appear to parallel FGF2 with lower potency. In addition to affecting bone via indirect phosphate wasting pathways, supraphysiological FGF23 and soluble Klotho may directly impact bone in diseases with elevated FGF23 levels.


Assuntos
Calcificação Fisiológica/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Fatores de Crescimento de Fibroblastos/farmacologia , Glucuronidase/farmacologia , Osteoblastos/efeitos dos fármacos , Animais , Células CHO , Células Cultivadas , Cricetinae , Cricetulus , Avaliação Pré-Clínica de Medicamentos , Fator de Crescimento de Fibroblastos 23 , Fatores de Crescimento de Fibroblastos/metabolismo , Humanos , Proteínas Klotho , Camundongos , Osteoblastos/metabolismo , Osteoblastos/fisiologia , Receptores de Fatores de Crescimento de Fibroblastos/genética , Receptores de Fatores de Crescimento de Fibroblastos/metabolismo , Estudos de Validação como Assunto
16.
Nat Commun ; 12(1): 6408, 2021 11 04.
Artigo em Inglês | MEDLINE | ID: mdl-34737316

RESUMO

Staphylococcus aureus pathogenicity islands (SaPIs) are molecular parasites that hijack helper phages for their transfer. SaPIbov5, the prototypical member of a family of cos type SaPIs, redirects the assembly of ϕ12 helper capsids from prolate to isometric. This size and shape shift is dependent on the SaPIbov5-encoded protein Ccm, a homolog of the ϕ12 capsid protein (CP). Using cryo-electron microscopy, we have determined structures of prolate ϕ12 procapsids and isometric SaPIbov5 procapsids. ϕ12 procapsids have icosahedral end caps with Tend = 4 architecture and a Tmid = 14 cylindrical midsection, whereas SaPIbov5 procapsids have T = 4 icosahedral architecture. We built atomic models for CP and Ccm, and show that Ccm occupies the pentameric capsomers in the isometric SaPIbov5 procapsids, suggesting that preferential incorporation of Ccm pentamers prevents the cylindrical midsection from forming. Our results highlight that pirate elements have evolved diverse mechanisms to suppress phage multiplication, including the acquisition of phage capsid protein homologs.


Assuntos
Staphylococcus/virologia , Capsídeo/metabolismo , Proteínas do Capsídeo/metabolismo , Ilhas Genômicas/genética
17.
J Exp Med ; 192(1): 137-43, 2000 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-10880535

RESUMO

We and others recently reported tumor necrosis factor (TNF) and apoptosis ligand-related leukocyte-expressed ligand 1 (TALL-1) as a novel member of the TNF ligand family that is functionally involved in B cell proliferation. Transgenic mice overexpressing TALL-1 have severe B cell hyperplasia and lupus-like autoimmune disease. Here, we describe expression cloning of a cell surface receptor for TALL-1 from a human Burkitt's lymphoma RAJI cell library. The cloned receptor is identical to the previously reported TNF receptor (TNFR) homologue transmembrane activator and calcium modulator and cyclophilin ligand (CAML) interactor (TACI). Murine TACI was subsequently isolated from the mouse B lymphoma A20 cells. Human and murine TACI share 54% identity overall. Human TACI exhibits high binding affinities to both human and murine TALL-1. Soluble TACI extracellular domain protein specifically blocks TALL-1-mediated B cell proliferation without affecting CD40- or lipopolysaccharide-mediated B cell proliferation in vitro. In addition, when injected into mice, soluble TACI inhibits antibody production to both T cell-dependent and -independent antigens. By yeast two-hybrid screening of a B cell library with TACI intracellular domain, we identified that, like many other TNFR family members, TACI intracellular domain interacts with TNFR-associated factor (TRAF)2, 5, and 6. Correspondingly, TACI activation in a B cell line results in nuclear factor kappaB and c-Jun NH(2)-terminal kinase activation. The identification and characterization of the receptor for TALL-1 provides useful information for the development of a treatment for B cell-mediated autoimmune diseases such as systemic lupus erythematosus.


Assuntos
Linfócitos B/imunologia , Proteínas de Membrana/fisiologia , Receptores do Fator de Necrose Tumoral/genética , Receptores do Fator de Necrose Tumoral/imunologia , Fator de Necrose Tumoral alfa/fisiologia , Sequência de Aminoácidos , Animais , Fator Ativador de Células B , Linfoma de Burkitt , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Biblioteca Gênica , Humanos , Ligantes , Ativação Linfocitária , Linfoma de Células B , Camundongos , Dados de Sequência Molecular , Receptores do Fator de Necrose Tumoral/química , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Proteína Transmembrana Ativadora e Interagente do CAML , Células Tumorais Cultivadas
18.
Anaesthesia ; 65(7): 745-8, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20337622

RESUMO

SUMMARY: Intra-operative blood cell salvage has recently been adopted for use in women at risk of significant haemorrhage during caesarean section. It has also been advocated for use in those patients who refuse allogenic blood transfusion. A 37-year-old pregnant woman (gravida 3, para 2) underwent an elective lower segment caesarean section at 36 weeks for an anterior, major placenta accreta (grade 4). The volume of cell salvaged blood collected during the procedure was 1870 ml. On starting the cell-salvaged blood transfusion, the blood pressure was noted to fall and this was temporally related to the transfusion of the cell-salvaged blood. We review the recent literature and case reports on hypotension related to cell-salvaged blood transfusion.


Assuntos
Transfusão de Sangue Autóloga/efeitos adversos , Hipotensão/etiologia , Complicações Intraoperatórias , Leucaférese/métodos , Adulto , Perda Sanguínea Cirúrgica , Cesárea , Feminino , Humanos , Cuidados Intraoperatórios/métodos , Gravidez , Hemorragia Uterina/cirurgia
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