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1.
Arterioscler Thromb Vasc Biol ; 44(9): 2024-2037, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39051116

RESUMO

BACKGROUND: In addition to their fundamental roles in preserving vascular integrity, platelets also contribute to tumor angiogenesis and metastasis. However, despite being a reservoir for angiogenic and metastatic cytokines, platelets also harbor negative regulators of tumor progression. Angpt1 (angiopoietin-1) is a cytokine essential for developmental angiogenesis that also protects against tumor cell metastasis through an undefined mechanism. Although activated platelets release Angpt1 from α-granules into circulation, the contributions of platelet Angpt1 to tumor growth, angiogenesis, and metastasis have not been investigated. METHODS: Using cytokine arrays and ELISAs, we first compared platelet Angpt1 levels in breast and melanoma mouse tumor models to tumor-free controls. We then assessed tumor growth and metastasis in mice lacking megakaryocyte and platelet Angpt1 (Angpt1Plt KO). The spontaneous metastasis of mammary-injected tumor cells to the lungs was quantified using RT-PCR (reverse transcription-polymerase chain reaction). The lung colonization of intravenously injected tumor cells and tumor cell extravasation were determined using fluorescent microscopy and flow cytometry. RESULTS: Platelet Angpt1 is selectively upregulated in the PyMT (polyoma middle tumor antigen) breast cancer mouse model, and platelets are the principal source of Angpt1 in blood circulation. While primary tumor growth and angiogenesis were unaffected, Angpt1Plt KO mice had both increased spontaneous lung metastasis and tumor cell lung colonization following mammary or intravenous injection, respectively. Although platelet Angpt1 did not affect initial tumor cell entrapment in the lungs, Angpt1Plt KO mice had increased tumor cell retention and extravasation. Serum from Angpt1Plt KO mice increased endothelial permeability and reduced VE (vascular endothelial)-cadherin expression at endothelial junctions compared with serum from control mice (Angpt1WT). CONCLUSIONS: Platelets provide an intravascular source of Angpt1 that restrains tumor metastasis by preserving the lung microvasculature to limit tumor cell extravasation.


Assuntos
Angiopoietina-1 , Plaquetas , Neoplasias Pulmonares , Camundongos Knockout , Neovascularização Patológica , Animais , Angiopoietina-1/genética , Angiopoietina-1/metabolismo , Angiopoietina-1/sangue , Plaquetas/metabolismo , Plaquetas/patologia , Feminino , Neoplasias Pulmonares/secundário , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/sangue , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/prevenção & controle , Camundongos Endogâmicos C57BL , Melanoma Experimental/patologia , Melanoma Experimental/metabolismo , Melanoma Experimental/irrigação sanguínea , Melanoma Experimental/sangue , Melanoma Experimental/secundário , Melanoma Experimental/genética , Linhagem Celular Tumoral , Camundongos , Neoplasias Mamárias Experimentais/patologia , Neoplasias Mamárias Experimentais/genética , Neoplasias Mamárias Experimentais/metabolismo , Neoplasias Mamárias Experimentais/sangue , Carga Tumoral , Modelos Animais de Doenças
2.
Semin Thromb Hemost ; 50(3): 455-461, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37832586

RESUMO

Alongside their conventional roles in thrombosis and hemostasis, platelets have long been associated with nonhemostatic pathologies, including tumor cell metastasis. Numerous mechanistic studies have since demonstrated that the direct binding of platelets to intravascular tumor cells promotes key hallmarks of metastasis, including survival in circulation and tumor cell arrest at secondary sites. However, platelets also interact with nonmalignant cells that make up the stromal and immune compartments within both primary and metastatic tumors. This review will first provide a brief historical perspective on platelet contributions to metastatic disease before discussing the emerging roles that platelets play in creating microenvironments that likely support successful tumor cell metastasis.


Assuntos
Neoplasias , Microambiente Tumoral , Humanos , Plaquetas/metabolismo , Neoplasias/metabolismo , Hemostasia , Metástase Neoplásica/patologia
3.
Clin Trials ; 21(1): 124-135, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-37615179

RESUMO

BACKGROUND: Comparative effectiveness research is meant to determine which commonly employed medical interventions are most beneficial, least harmful, and/or most costly in a real-world setting. While the objectives for comparative effectiveness research are clear, the field has failed to develop either a uniform definition of comparative effectiveness research or an appropriate set of recommendations to provide standards for the design of critical care comparative effectiveness research trials, spurring controversy in recent years. The insertion of non-representative control and/or comparator arm subjects into critical care comparative effectiveness research trials can threaten trial subjects' safety. Nonetheless, the broader scientific community does not always appreciate the importance of defining and maintaining critical care practices during a trial, especially when vulnerable, critically ill populations are studied. Consequently, critical care comparative effectiveness research trials sometimes lack properly constructed control or active comparator arms altogether and/or suffer from the inclusion of "unusual critical care" that may adversely affect groups enrolled in one or more arms. This oversight has led to critical care comparative effectiveness research trial designs that impair informed consent, confound interpretation of trial results, and increase the risk of harm for trial participants. METHODS/EXAMPLES: We propose a novel approach to performing critical care comparative effectiveness research trials that mandates the documentation of critical care practices prior to trial initiation. We also classify the most common types of critical care comparative effectiveness research trials, as well as the most frequent errors in trial design. We present examples of these design flaws drawn from past and recently published trials as well as examples of trials that avoided those errors. Finally, we summarize strategies employed successfully in well-designed trials, in hopes of suggesting a comprehensive standard for the field. CONCLUSION: Flawed critical care comparative effectiveness research trial designs can lead to unsound trial conclusions, compromise informed consent, and increase risks to research subjects, undermining the major goal of comparative effectiveness research: to inform current practice. Well-constructed control and comparator arms comprise indispensable elements of critical care comparative effectiveness research trials, key to improving the trials' safety and to generating trial results likely to improve patient outcomes in clinical practice.


Assuntos
Braço , Pesquisa Comparativa da Efetividade , Humanos , Consentimento Livre e Esclarecido , Sujeitos da Pesquisa , Cuidados Críticos
4.
Blood ; 137(23): 3174-3180, 2021 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-33940594

RESUMO

Platelets have long been known to play important roles beyond hemostasis and thrombosis. Now recognized as a bona fide mediator of malignant disease, platelets influence various aspects of cancer progression, most notably tumor cell metastasis. Interestingly, platelets isolated from cancer patients often display distinct RNA and protein profiles, with no clear alterations in hemostatic activity. This phenotypically distinct population, termed tumor-educated platelets, now receive significant attention for their potential use as a readily available liquid biopsy for early cancer detection. Although the mechanisms underpinning platelet education are still being defined, direct uptake and storage of tumor-derived factors, signal-dependent changes in platelet RNA processing, and differential platelet production by tumor-educated megakaryocytes are the most prominent scenarios. This article aims to cover the various modalities of platelet education by tumors, in addition to assessing their diagnostic potential.


Assuntos
Plaquetas/metabolismo , Megacariócitos/metabolismo , Proteínas de Neoplasias/metabolismo , Neoplasias/metabolismo , RNA Neoplásico/metabolismo , Animais , Plaquetas/patologia , Humanos , Biópsia Líquida , Megacariócitos/patologia , Metástase Neoplásica , Neoplasias/diagnóstico , Neoplasias/patologia
5.
Ann Surg ; 275(6): 1094-1102, 2022 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-35258509

RESUMO

OBJECTIVE: To design and establish a prospective biospecimen repository that integrates multi-omics assays with clinical data to study mechanisms of controlled injury and healing. BACKGROUND: Elective surgery is an opportunity to understand both the systemic and focal responses accompanying controlled and well-characterized injury to the human body. The overarching goal of this ongoing project is to define stereotypical responses to surgical injury, with the translational purpose of identifying targetable pathways involved in healing and resilience, and variations indicative of aberrant peri-operative outcomes. METHODS: Clinical data from the electronic medical record combined with large-scale biological data sets derived from blood, urine, fecal matter, and tissue samples are collected prospectively through the peri-operative period on patients undergoing 14 surgeries chosen to represent a range of injury locations and intensities. Specimens are subjected to genomic, transcriptomic, proteomic, and metabolomic assays to describe their genetic, metabolic, immunologic, and microbiome profiles, providing a multidimensional landscape of the human response to injury. RESULTS: The highly multiplexed data generated includes changes in over 28,000 mRNA transcripts, 100 plasma metabolites, 200 urine metabolites, and 400 proteins over the longitudinal course of surgery and recovery. In our initial pilot dataset, we demonstrate the feasibility of collecting high quality multi-omic data at pre- and postoperative time points and are already seeing evidence of physiologic perturbation between timepoints. CONCLUSIONS: This repository allows for longitudinal, state-of-the-art geno-mic, transcriptomic, proteomic, metabolomic, immunologic, and clinical data collection and provides a rich and stable infrastructure on which to fuel further biomedical discovery.


Assuntos
Biologia Computacional , Proteômica , Genômica , Humanos , Metabolômica , Estudos Prospectivos , Proteômica/métodos
6.
Am J Physiol Heart Circ Physiol ; 320(6): H2385-H2400, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-33989079

RESUMO

Cell-free hemoglobin (CFH) levels are elevated in septic shock and are higher in nonsurvivors. Whether CFH is only a marker of sepsis severity or is involved in pathogenesis is unknown. This study aimed to investigate whether CFH worsens sepsis-associated injuries and to determine potential mechanisms of harm. Fifty-one, 10-12 kg purpose-bred beagles were randomized to receive Staphylococcus aureus intrapulmonary challenges or saline followed by CFH infusions (oxyhemoglobin >80%) or placebo. Animals received antibiotics and intensive care support for 96 h. CFH significantly increased mean pulmonary arterial pressures and right ventricular afterload in both septic and nonseptic animals, effects that were significantly greater in nonsurvivors. These findings are consistent with CFH-associated nitric oxide (NO) scavenging and were associated with significantly depressed cardiac function, and worsened shock, lactate levels, metabolic acidosis, and multiorgan failure. In septic animals only, CFH administration significantly increased mean alveolar-arterial oxygenation gradients, also to a significantly greater degree in nonsurvivors. CFH-associated iron levels were significantly suppressed in infected animals, suggesting that bacterial iron uptake worsened pneumonia. Notably, cytokine levels were similar in survivors and nonsurvivors and were not predictive of outcome. In the absence and presence of infection, CFH infusions resulted in pulmonary hypertension, cardiogenic shock, and multiorgan failure, likely through NO scavenging. In the presence of infection alone, CFH infusions worsened oxygen exchange and lung injury, presumably by supplying iron that promoted bacterial growth. CFH elevation, a known consequence of clinical septic shock, adversely impacts sepsis outcomes through more than one mechanism, and is a biologically plausible, nonantibiotic, noncytokine target for therapeutic intervention.NEW & NOTEWORTHY Cell-free hemoglobin (CFH) elevations are a known consequence of clinical sepsis. Using a two-by-two factorial design and extensive physiological and biochemical evidence, we found a direct mechanism of injury related to nitric oxide scavenging leading to pulmonary hypertension increasing right heart afterload, depressed cardiac function, worsening circulatory failure, and death, as well as an indirect mechanism related to iron toxicity. These discoveries alter conventional thinking about septic shock pathogenesis and provide novel therapeutic approaches.


Assuntos
Hemoglobinas/metabolismo , Pneumonia/metabolismo , Artéria Pulmonar/fisiopatologia , Choque Séptico/metabolismo , Infecções Estafilocócicas/metabolismo , Acidose/metabolismo , Acidose/fisiopatologia , Lesão Pulmonar Aguda/metabolismo , Lesão Pulmonar Aguda/fisiopatologia , Animais , Pressão Sanguínea/efeitos dos fármacos , Pressão Sanguínea/fisiologia , Cães , Ventrículos do Coração/efeitos dos fármacos , Ventrículos do Coração/fisiopatologia , Hemoglobinas/farmacologia , Ferro/metabolismo , Ácido Láctico/metabolismo , Insuficiência de Múltiplos Órgãos/metabolismo , Insuficiência de Múltiplos Órgãos/fisiopatologia , Óxido Nítrico/metabolismo , Pneumonia/fisiopatologia , Troca Gasosa Pulmonar , Distribuição Aleatória , Choque Séptico/fisiopatologia , Staphylococcus aureus/crescimento & desenvolvimento
7.
Vox Sang ; 116(4): 451-463, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33567470

RESUMO

BACKGROUND AND OBJECTIVES: Next generation sequencing (NGS) has promising applications in transfusion medicine. Exome sequencing (ES) is increasingly used in the clinical setting, and blood group interpretation is an additional value that could be extracted from existing data sets. We provide the first release of an open-source software tailored for this purpose and describe its validation with three blood group systems. MATERIALS AND METHODS: The DTM-Tools algorithm was designed and used to analyse 1018 ES NGS files from the ClinSeq® cohort. Predictions were correlated with serology for 5 antigens in a subset of 108 blood samples. Discrepancies were investigated with alternative phenotyping and genotyping methods, including a long-read NGS platform. RESULTS: Of 116 genomic variants queried, those corresponding to 18 known KEL, FY and JK alleles were identified in this cohort. 596 additional exonic variants were identified KEL, ACKR1 and SLC14A1, including 58 predicted frameshifts. Software predictions were validated by serology in 108 participants; one case in the FY blood group and three cases in the JK blood group were discrepant. Investigation revealed that these discrepancies resulted from (1) clerical error, (2) serologic failure to detect weak antigenic expression and (3) a frameshift variant absent in blood group databases. CONCLUSION: DTM-Tools can be employed for rapid Kell, Duffy and Kidd blood group antigen prediction from existing ES data sets; for discrepancies detected in the validation data set, software predictions proved accurate. DTM-Tools is open-source and in continuous development.


Assuntos
Alelos , Antígenos de Grupos Sanguíneos/análise , Antígenos de Grupos Sanguíneos/genética , Sequenciamento do Exoma/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Software , Sistema do Grupo Sanguíneo Duffy/genética , Variação Genética , Técnicas de Genotipagem , Humanos , Glicoproteínas de Membrana/genética , Proteínas de Membrana Transportadoras/genética , Metaloendopeptidases/genética , Receptores de Superfície Celular/genética , Transportadores de Ureia
8.
World J Surg ; 45(12): 3543-3557, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34486080

RESUMO

BACKGROUND: Injury is the leading cause of morbidity and mortality in low- and lower middle-income countries (LMICs). Trauma training is a cost-effective way to improve injury outcomes. Several trauma programs have been implemented in LMICs; however, their scope and effectiveness remain unclear. In this review, we sought to describe and assess the current state of trauma training in LMICs. METHODS: We searched MEDLINE, Embase, Global Health, Cochrane Library, and ProQuest Dissertations & Theses Global for trauma training courses in LMICs. An additional gray literature search was conducted on university, governmental, and non- governmental organizations' websites to identify trauma-related postgraduate medical education (PGME) opportunities. RESULTS: Most studies occurred in sub-Saharan Africa and participants were primarily physicians/surgeons, medical students/residents, and nurses. General and surgical trauma management courses were most common, followed by orthopedic trauma or plastic surgery trauma/burn care courses. 32/45 studies reported on participant knowledge and skills, 27 of which had minimal follow-up. Of the four studies commenting on cost of courses, only one demonstrated cost-effectiveness. Three articles evaluated post-course effects on patient outcomes, two of which failed to demonstrate significant improvements. Overall, 43.0% of LMICs have PGME programs with defined trauma competency requirements. CONCLUSIONS: Current studies on trauma training in LMICs do not clearly demonstrate sustainability, cost-effectiveness, nor improved outcomes. Trauma training programs should be in response to a need, championed locally, and work within a cohesive system to demonstrate concrete benefits. We recommend standardized and contextualized trauma training with recertifications in LMICs for lasting and improved trauma care.


Assuntos
Países em Desenvolvimento , Educação Médica , Humanos , Pobreza
9.
Transfusion ; 60(4): 698-712, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32086946

RESUMO

BACKGROUND: In experimental canine septic shock, depressed circulating granulocyte counts were associated with a poor outcome and increasing counts with prophylactic granulocyte colony-stimulating factor (G-CSF) improved outcome. Therapeutic G-CSF, in contrast, did not improve circulating counts or outcome, and therefore investigation was undertaken to determine whether transfusing granulocytes therapeutically would improve outcome. STUDY DESIGN AND METHODS: Twenty-eight purpose-bred beagles underwent an intrabronchial Staphylococcus aureus challenge and 4 hours later were randomly assigned to granulocyte (40-100 × 109 cells) or plasma transfusion. RESULTS: Granulocyte transfusion significantly expanded the low circulating counts for hours compared to septic controls but was not associated with significant mortality benefit (1/14, 7% vs. 2/14, 14%, respectively; p = 0.29). Septic animals with higher granulocyte count at 4 hours (median [interquartile range] of 3.81 3.39-5.05] vs. 1.77 [1.25-2.50]) had significantly increased survival independent of whether they were transfused with granulocytes. In a subgroup analysis, animals with higher circulating granulocyte counts receiving donor granulocytes had worsened lung injury compared to septic controls. Conversely, donor granulocytes decreased lung injury in septic animals with lower counts. CONCLUSION: During bacterial pneumonia, circulating counts predict the outcome of transfusing granulocytes. With low but normal counts, transfusing granulocytes does not improve survival and injures the lung, whereas for animals with very low counts, but not absolute neutropenia, granulocyte transfusion improves lung function.


Assuntos
Granulócitos/transplante , Pneumonia Bacteriana/terapia , Animais , Modelos Animais de Doenças , Cães , Fator Estimulador de Colônias de Granulócitos/uso terapêutico , Granulócitos/citologia , Contagem de Leucócitos , Transfusão de Leucócitos , Lesão Pulmonar/prevenção & controle , Pneumonia Bacteriana/mortalidade , Staphylococcus aureus/patogenicidade , Doadores de Tecidos , Resultado do Tratamento
10.
Transfusion ; 59(1): 303-315, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30362577

RESUMO

BACKGROUND: Patients undergoing allogeneic hematopoietic stem cell transplant require variable, often extensive transfusion support. Identification of factors that predict urgent, intensive, or special needs should improve management of these patients. STUDY DESIGN AND METHODS: This is a retrospective study of red blood cell (RBC) and platelet transfusion support provided for sequential matched sibling donor allogeneic transplants conducted at the Clinical Center, National Institutes of Health, from 1993 through 2010. Factors potentially important for predicting quantity of RBC and platelet transfusions, and time to transfusion independence through Day 200 following hematopoietic stem cell transplantation were evaluated. RESULTS: Subjects (n = 800) received 10,591 RBC and 10,199 platelet transfusions. Multivariable analysis demonstrated that the need for RBC pretransplant, CD34+ dose, transplant year, diagnostic category, and ABO match were significantly independently associated with quantity of RBC transfusions during Days 0 through 30. Only pretransplant need for RBCs, CD34+ dose, and transplant year had significance during Days 0 through 100. Similar analyses for quantity of platelet transfusions demonstrated that for both Days 0 through 30 and 0 through 100 significant factors were need for platelet support before transplant, CD34+ dose, transplant year, and transplant regimen. Of note, long term, during Days 101 through 200, only CD34+ dose remained significant for quantity of RBC and platelet transfusions. Analysis of time to transfusion independence demonstrated that patients with ABO major mismatches required longer to achieve freedom from RBC transfusion support compared to identical matches or those with minor mismatches. CONCLUSION: Patient-specific factors including CD34+ dose and ABO match of the graft should be given particular consideration by transfusion services when planning support of patients receiving allogeneic hematopoietic stem cell transplant.


Assuntos
Transfusão de Sangue/métodos , Transplante de Células-Tronco Hematopoéticas/métodos , Sistema ABO de Grupos Sanguíneos , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Transfusão de Eritrócitos/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Transfusão de Plaquetas/métodos , Estudos Retrospectivos , Irmãos , Adulto Jovem
11.
Transfusion ; 59(12): 3628-3638, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31639229

RESUMO

BACKGROUND: During sepsis, higher plasma cell-free hemoglobin (CFH) levels portend worse outcomes. In sepsis models, plasma proteins that bind CFH improve survival. In our canine antibiotic-treated Staphylococcus aureus pneumonia model, with and without red blood cell (RBC) exchange transfusion, commercial human haptoglobin (Hp) concentrates bound and compartmentalized CFH intravascularly, increased CFH clearance, and lowered iron levels, improving shock, lung injury, and survival. We now investigate in our model how very high CFH levels and treatment time affect Hp's beneficial effects. MATERIALS AND METHODS: Two separate canine pneumonia sepsis Hp studies were undertaken: one with exchange transfusion of RBCs after prolonged storage to raise CFH to very high levels and another with rapidly lethal sepsis alone to shorten time to treat. All animals received continuous standard intensive care unit supportive care for 96 hours. RESULTS: Older RBCs markedly elevated plasma CFH levels and, when combined with Hp therapy, created supraphysiologic CFH-Hp complexes that did not increase CFH or iron clearance or improve lung injury and survival. In a rapidly lethal bacterial challenge model without RBC transfusion, Hp binding did not increase clearance of complexes or iron or show benefits seen previously in the less lethal model. DISCUSSION: High-level CFH-Hp complexes may impair clearance mechanisms and eliminate Hp's beneficial effect during sepsis. Rapidly lethal sepsis narrows the therapeutic window for CFH and iron clearance, also decreasing Hp's beneficial effects. In designing clinical trials, dosing and kinetics may be critical factors if Hp infusion is used to treat sepsis.


Assuntos
Haptoglobinas/uso terapêutico , Hemoglobinas/metabolismo , Pneumonia Estafilocócica/tratamento farmacológico , Pneumonia Estafilocócica/metabolismo , Choque Séptico/tratamento farmacológico , Choque Séptico/metabolismo , Animais , Modelos Animais de Doenças , Cães , Transfusão de Eritrócitos , Pneumonia Estafilocócica/terapia , Sepse/tratamento farmacológico , Sepse/metabolismo , Sepse/terapia , Choque Séptico/terapia
12.
Transfusion ; 59(1): 347-358, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30383305

RESUMO

BACKGROUND: Storage temperature is a critical factor for maintaining red-blood cell (RBC) viability, especially during prolonged cold storage. The target range of 1 to 6°C was established decades ago and may no longer be optimal for current blood-banking practices. STUDY DESIGN AND METHODS: Human and canine RBCs were collected under standard conditions and stored in precision-controlled refrigerators at 2°C, 4°C, or 6°C. RESULTS: During 42-day storage, human and canine RBCs showed progressive increases in supernatant non-transferrin-bound iron, cell-free hemoglobin, base deficit, and lactate levels that were overall greater at 6°C and 4°C than at 2°C. Animals transfused with 7-day-old RBCs had similar plasma cell-free hemoglobin and non-transferrin-bound iron levels at 1 to 72 hours for all three temperature conditions by chromium-51 recovery analysis. However, animals transfused with 35-day-old RBCs stored at higher temperatures developed plasma elevations in non-transferrin-bound iron and cell-free hemoglobin at 24 and 72 hours. Despite apparent impaired 35-day storage at 4°C and 6°C compared to 2°C, posttransfusion chromium-51 recovery at 24 hours was superior at higher temperatures. This finding was confounded by a preparation artifact related to an interaction between temperature and storage duration that leads to removal of fragile cells with repeated washing of the radiolabeled RBC test sample and renders the test sample unrepresentative of the stored unit. CONCLUSIONS: RBCs stored at the lower bounds of the temperature range are less metabolically active and produce less anaerobic acidosis and hemolysis, leading to a more suitable transfusion product. The higher refrigeration temperatures are not optimal during extended RBC storage and may confound chromium viability studies.


Assuntos
Preservação de Sangue/métodos , Cromo/metabolismo , Eritrócitos/citologia , Animais , Células Cultivadas , Cães , Hemólise/fisiologia , Humanos , Temperatura
13.
Lupus ; 28(9): 1101-1110, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31291843

RESUMO

AIM: The aim of this study was to identify factors predictive of serious infections over time in patients with systemic lupus erythematosus (SLE). METHODS: A multi-ethnic, multi-national Latin American SLE cohort was studied. Serious infection was defined as one that required hospitalization, occurred during a hospitalization or led to death. Potential predictors included were sociodemographic factors, clinical manifestations (per organ involved, lymphopenia and leukopenia, independently) and previous infections at baseline. Disease activity (SLEDAI), damage (SLICC/ACR Damage Index), non-serious infections, glucocorticoids, antimalarials (users and non-users), and immunosuppressive drugs use; the last six variables were examined as time-dependent covariates. Cox regression models were used to evaluate the predictors of serious infections using a backward elimination procedure. Univariable and multivariable analyses were performed. RESULTS: Of the 1243 patients included, 1116 (89.8%) were female. The median (interquartile range) age at diagnosis and follow-up time were 27 (20-37) years and 47.8 (17.9-68.6) months, respectively. The incidence rate of serious infections was 3.8 cases per 100 person-years. Antimalarial use (hazard ratio: 0.69; 95% confidence interval (CI): 0.48-0.99; p = 0.0440) was protective, while doses of prednisone >15 and ≤60 mg/day (hazard ratio: 4.18; 95 %CI: 1.69-10.31; p = 0.0019) and >60 mg/day (hazard ratio: 4.71; 95% CI: 1.35-16.49; p = 0.0153), use of methylprednisolone pulses (hazard ratio: 1.53; 95% CI: 1.10-2.13; p = 0.0124), increase in disease activity (hazard ratio: 1.03; 95% CI: 1.01-1.04; p = 0.0016) and damage accrual (hazard ratio: 1.22; 95% CI: 1.11-1.34; p < 0.0001) were predictive factors of serious infections. CONCLUSIONS: Over time, prednisone doses higher than 15 mg/day, use of methylprednisolone pulses, increase in disease activity and damage accrual were predictive of infections, whereas antimalarial use was protective against them in SLE patients.


Assuntos
Hospitalização/estatística & dados numéricos , Infecções/epidemiologia , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Adulto , Antimaláricos/administração & dosagem , Estudos de Coortes , Relação Dose-Resposta a Droga , Feminino , Seguimentos , Glucocorticoides/administração & dosagem , Humanos , Imunossupressores/administração & dosagem , Infecções/etiologia , América Latina , Lúpus Eritematoso Sistêmico/fisiopatologia , Masculino , Metilprednisolona/administração & dosagem , Prednisona/administração & dosagem , Fatores de Proteção , Fatores de Risco , Índice de Gravidade de Doença , Adulto Jovem
14.
Clin Exp Dermatol ; 44(4): e140-e144, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30628104

RESUMO

BACKGROUND: Vulval intraepithelial neoplasia (VIN) is a precancerous condition that may progress to invasive malignancy. VIN is associated with human papillomavirus (HPV) infection in most cases, and with inflammatory skin disorders in a smaller proportion of patients. Treatment of VIN has traditionally been surgical excision; however, topical treatments, including imiquimod cream, are becoming increasingly used. Patient factors influencing response to imiquimod therapy, in particular smoking, have not yet been published. AIM: To assess the impact of smoking and other patient characteristics that may influence the treatment response to topical imiquimod for VIN. METHODS: This was a retrospective cohort study of 46 women treated with topical imiquimod for VIN in a single centre dermatology unit from January 2011 to July 2017. RESULTS: Complete clinical resolution of VIN was observed in 28 of 46 patients (61%), but was significantly reduced in the smoking cohort. CONCLUSIONS: Smoking may impair response to imiquimod for VIN, and should be considered when discussing VIN treatment options with patients.


Assuntos
Imiquimode/uso terapêutico , Fumar/efeitos adversos , Neoplasias Vulvares/tratamento farmacológico , Adjuvantes Imunológicos/uso terapêutico , Administração Tópica , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma in Situ/patologia , Feminino , Humanos , Imiquimode/administração & dosagem , Pessoa de Meia-Idade , Infecções por Papillomavirus/complicações , Estudos Retrospectivos , Resultado do Tratamento , Neoplasias Vulvares/epidemiologia , Neoplasias Vulvares/patologia
15.
Curr Opin Hematol ; 25(5): 410-415, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29985173

RESUMO

PURPOSE OF REVIEW: Platelets are small, anucleate cells that circulate within the blood and play essential roles in preserving vascular integrity. However, abnormalities in either platelet production or destruction can result in thrombocytopenia, clinically defined by a platelet count lower than 150 000/µL of whole blood. Thrombocytopenia is frequently associated with impaired hemostatic responses to vascular injury and can be life-threatening because of bleeding complications. Megakaryocytes are the precursor cells responsible for platelet production, a process commonly referred to as thrombopoiesis. This review specifically discusses how perturbation of molecular mechanisms governing megakaryocyte differentiation and development manifest in various forms of thrombocytopenia. RECENT FINDINGS: This review highlights the identification of novel transcriptional regulators of megakaryocyte maturation and platelet production. We also provide an update into the essential role of cytoskeletal regulation in thrombopoiesis, and how both megakaryopoiesis and platelet production are altered by anticancer therapeutics. Lastly, we focus on recent investigative approaches to treat thrombocytopenia and discuss future prospects in the field of megakaryocyte research. SUMMARY: In patients where thrombocytopenia is not due to heightened platelet destruction or clearance, defects in megakaryocyte development should be considered.


Assuntos
Plaquetas/metabolismo , Hemostasia , Megacariócitos/metabolismo , Trombocitopenia/metabolismo , Trombopoese , Animais , Plaquetas/patologia , Citoesqueleto/metabolismo , Citoesqueleto/patologia , Hemorragia/metabolismo , Hemorragia/patologia , Humanos , Megacariócitos/patologia , Contagem de Plaquetas , Trombocitopenia/patologia
16.
Transfusion ; 58(11): 2693-2704, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30312480

RESUMO

BACKGROUND: The 1000 Genomes Project provides a database of genomic variants from whole genome sequencing of 2504 individuals across five continental superpopulations. This database can enrich our background knowledge of worldwide blood group variant geographic distribution and identify novel variants of potential clinical significance. STUDY DESIGN AND METHODS: The 1000 Genomes database was analyzed to 1) expand knowledge about continental distributions of known blood group variants, 2) identify novel variants with antigenic potential and their geographic association, and 3) establish a baseline scaffold of chromosomal coordinates to translate next-generation sequencing output files into a predicted red blood cell (RBC) phenotype. RESULTS: Forty-two genes were investigated. A total of 604 known variants were mapped to the GRCh37 assembly; 120 of these were reported by 1000 Genomes in at least one superpopulation. All queried variants, including the ACKR1 promoter silencing mutation, are located within exon pull-down boundaries. The analysis yielded 41 novel population distributions for 34 known variants, as well as 12 novel blood group variants that warrant further validation and study. Four prediction algorithms collectively flagged 79 of 109 (72%) known antigenic or enzymatically detrimental blood group variants, while 4 of 12 variants that do not result in an altered RBC phenotype were flagged as deleterious. CONCLUSION: Next-generation sequencing has known potential for high-throughput and extended RBC phenotype prediction; a database of GRCh37 and GRCh38 chromosomal coordinates for 120 worldwide blood group variants is provided as a basis for this clinical application.


Assuntos
Genoma Humano/genética , Genômica/métodos , Algoritmos , Antígenos de Grupos Sanguíneos/genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos
17.
BMC Palliat Care ; 17(1): 129, 2018 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-30572859

RESUMO

BACKGROUND: An understanding of how to implement person-centred interventions in palliative and end of life care is lacking, particularly for supporting family carers. To address this gap, we investigated components related to successful implementation of the Carer Support Needs Assessment Tool (CSNAT) intervention, a person-centred process of carer assessment and support, using Promoting Action on Research Implementation in Health Services (PARIHS) as a theoretical framework. This study identifies how the PARIHS component of 'facilitation' and its interplay with the components of 'context' and 'evidence' affect implementation success. METHODS: MRC Framework Phase IV study to evaluate implementation of the CSNAT intervention at scale, over six months, in 36 UK palliative care services. 38 practitioners acting as internal facilitators in 35/36 services were interviewed. Field notes were collected during teleconference support sessions between the external and internal facilitators. RESULTS: Successful implementation was associated with internal facilitators' 'leverage' including their positioning within services, authority to change practice, and having a team of supportive co-facilitators. Effective facilitation processes included a collaborative approach, ongoing communication, and proactive problem solving to address implementation barriers. Facilitators needed to communicate the evidence and provide legitimacy for changing practice. Contextual constraints on facilitation included having to adjust recording systems to support implementation, organisational changes, a patient-focused culture and lack of managerial support. CONCLUSIONS: The CSNAT intervention requires attention to both facilitation processes and conducive organisational structures for successful implementation. These findings are likely to be applicable to any person-centred process of assessment and support within palliative care.


Assuntos
Atitude do Pessoal de Saúde , Cuidadores/psicologia , Facilitação Social , Humanos , Entrevistas como Assunto , Avaliação das Necessidades , Avaliação de Processos e Resultados em Cuidados de Saúde , Cuidados Paliativos , Psicometria , Medicina Estatal , Inquéritos e Questionários , Reino Unido
18.
Cancer ; 123(8): 1434-1441, 2017 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-27984651

RESUMO

BACKGROUND: Short-course radiotherapy (SC-RT) and long-course chemoradiotherapy (LC-CRT) are accepted neoadjuvant treatments of rectal cancer. In the current study, the authors surveyed US radiation oncologists to assess practice patterns and attitudes regarding SC-RT and LC-CRT for patients with rectal cancer. METHODS: The authors distributed a survey to 1701 radiation oncologists regarding treatment of neoadjuvant rectal cancer. Respondents were asked questions regarding the number of patients with rectal cancer treated, preference for SC-RT versus LC-CRT, and factors influencing regimen choice. RESULTS: Of 1659 contactable physicians, 182 responses (11%) were received. Approximately 83% treated at least 5 patients with rectal cancer annually. The majority of responding radiation oncologists (96%) preferred neoadjuvant LC-CRT for the treatment of patients with locally advanced rectal cancer and 44% never used SC-RT. Among radiation oncologists using SC-RT, respondents indicated they would not recommend this regimen for patients with low (74%) or bulky tumors (70%) and/or concern for a positive circumferential surgical resection margin (69%). The most frequent reasons for not offering SC-RT were insufficient downstaging for sphincter preservation (53%) and a desire for longer follow-up (45%). Many radiation oncologists indicated they would prescribe SC-RT for patients not receiving chemotherapy (62%) or patients with a geographic barrier to receiving LC-CRT (82%). Patient comorbidities appeared to influence regimen preferences for 79% of respondents. Approximately 20% of respondents indicated that altered oncology care reimbursement using capitated payment by diagnosis would impact their consideration of SC-RT. CONCLUSIONS: US radiation oncologists rarely use neoadjuvant SC-RT despite 3 randomized controlled trials demonstrating no significant differences in outcome compared with LC-CRT. Further research is necessary to determine whether longer follow-up coupled with the benefits of lower cost, increased patient convenience, and lower acute toxicity will increase the adoption of SC-RT by radiation oncologists in the United States. Cancer 2017;123:1434-1441. © 2016 American Cancer Society.


Assuntos
Padrões de Prática Médica , Radio-Oncologistas , Neoplasias Retais/epidemiologia , Neoplasias Retais/terapia , Atitude , Quimiorradioterapia , Feminino , Pesquisas sobre Atenção à Saúde , Humanos , Masculino , Terapia Neoadjuvante , Estadiamento de Neoplasias , Neoplasias Retais/patologia , Estados Unidos/epidemiologia
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