Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 54
Filtrar
1.
Trop Anim Health Prod ; 55(2): 80, 2023 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-36786899

RESUMO

Tanniferous browse leaves are reported to inhibit methanogens and protozoa activity in the rumen, thus contributing to a reduction of methane emission. This study evaluated the influence of feeding dried browse leaves to sheep on rumen ammonia concentration, the base pair at which protozoa and methanogens were amplified and double stranded DNA concentration (dsDNA) from rumen fluid and faeces. The eight treatments were urea treated rice straw, Albizzia lebbek (AL), Moringa oleifera (MO), Millettia thonningii (MT), AL + MO, AL + MT, AL + MO + MT and MO + MT. After feeding 32 ram lambs for 3 months, one ram lamb on each of the eight experimental diets was randomly selected and slaughtered to obtain rumen fluid. Genomic DNAs were extracted from methanogen and protozoa strains obtained from rumen liquor and from faecal matter of sheep. Rumen ammonia was determined using spectrophotometer. Methanogens and protozoa from rumen fluid and faeces were amplified at 1100 base pair, 200-1100 base pair, 320-1100 base pair and 200-750 base pair respectively. Rumen ammonia concentration, dsDNA from rumen fluid and faeces ranged from 14.51 to 23.01 mg/dl, 65 to 900 µg/ml and 100 to 950 µg/g respectively. The rumen ammonia concentration met the requirements for efficient growth of microbes. The presence of methanogens and protozoa in the rumen fluid and in the faeces indicated that dried browse diets were able to inhibit the growth of both protozoa and methanogens in the rumen by eliminating them, and thus, were excreted in the faeces. Hence, feeding of dried browse leaves can contribute to lower methane emission.


Assuntos
Amônia , Rúmen , Ovinos , Animais , Masculino , Rúmen/metabolismo , Amônia/metabolismo , Gana , Folhas de Planta , Metano/metabolismo , Fermentação
2.
J Acoust Soc Am ; 149(3): 1855, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33765802

RESUMO

This study focuses on the differences in speech sound pressure levels (here, called speech loudness) of Lombard speech (i.e., speech produced in the presence of an energetic masker) associated with different tasks and language nativeness. Vocalizations were produced by native speakers of Japanese with normal hearing and limited English proficiency while performing four tasks: dialog, a competitive game (both communicative), soliloquy, and text passage reading (noncommunicative). Relative to the native language (L1), larger loudness increments were observed in the game and text reading when performed in the second language (L2). Communicative tasks yielded louder vocalizations and larger increments of speech loudness than did noncommunicative tasks regardless of the spoken language. The period in which speakers increased their loudness after the onset of the masker was about fourfold longer than the time in which they decreased their loudness after the offset of the masker. Results suggest that when relying on acoustic signals, speakers use similar vocalization strategies in L1 and L2, and these depend on the complexity of the task, the need for accurate pronunciation, and the presence of a listener. Results also suggest that speakers use different strategies depending on the onset or offset of an energetic masker.


Assuntos
Multilinguismo , Percepção da Fala , Idioma , Fonética , Fala
3.
J Environ Manage ; 249: 109420, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31445369

RESUMO

As in other semi-arid savannah systems of the world characterised by highly mobile and/or migratory ungulates, Botswana's rangelands are experiencing increased fragmentation due to expanding human activities and increasing human wildlife conflict. Climate change scenarios show Botswana becoming hotter and drier with mega droughts, heat waves and more intense and spatially confined rainfall events. The Botswana Government has reacted by providing artificial water points (AWPs) in the Protected Areas and surrounding Wildlife Management Areas (WMAs), in part to compensate for the lack of access to historical sources due to fences and human expansion. Blanket provision of AWPs will disrupt the existing mobility and migratory strategies of the key ungulates that is basic to their survival and their ability to adapt to climate change. Botswana's burgeoning elephant population has already effectively re-connected the drier Kalahari System to the Northern System by breaching fences in the region. The key recommendations from the past are used to reinforce the need for ecosystem management for resilience at the landscape level via migratory corridors through shared landscapes, made possible by a renewed focus on Community Based Natural Resource Management and Payments for Ecosystem Services. The events that have occurred over the last 50 years are used to illustrate the dangers of managing at the wrong 'localised' spatial and temporal scale and failing to address the key factors of mobility and inequity that characterise the ecological and socio-economic systems, respectively.


Assuntos
Conservação dos Recursos Naturais , Ecossistema , Animais , Botsuana , Mudança Climática , Secas , Humanos
4.
Breast Cancer Res Treat ; 168(2): 501-511, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29247440

RESUMO

PURPOSE: Breast tumors from young women under the age of 40 account for approximately 7% of cases and have a poor prognosis independent of established prognostic factors. We evaluated the patient population served by the Military Health System, where a disproportionate number of breast cancer cases in young women are seen and treated in a single universal coverage healthcare system. METHODS: The Military Health System Repository and the DoD Central Registration databases were used to identify female breast cancer patients diagnosed or treated at military treatment facilities from 1998 to 2007. RESULTS: 10,066 women were diagnosed with invasive breast cancer at DoD facilities from 1998 to 2007, of which 11.3% (1139), 23.4% (2355) and 65.2% (6572) were < 40, 40-49 and > 50 years old (yo), respectively, at diagnosis. 53% in the < 40 yo cohort were white, 25% were African American (AA) and 8% were Hispanic, with 14% undisclosed. Breast cancer in women diagnosed < 40 yo was more high grade (p < 0.0001), Stage II (p < 0.0001) and ER negative (p < 0.0001). There was a higher rate of bilateral mastectomies among the women < 40 compared to those 40-49 and > 50 (18.4% vs. 9.1% and 5.0%, respectively). Independent of disease stage, chemotherapy was given more frequently to < 40 yo (90.43%) and 40-49 yo (81.44%) than ≥ 50 yo (53.71%). The 10-year overall survival of younger women was similar to the ≥ 50 yo cohort. Outcomes in the African American and Hispanic subpopulations were comparable to the overall cohort. CONCLUSION: Younger women had a similar overall survival rate to older women despite receiving more aggressive treatment.


Assuntos
Neoplasias da Mama/epidemiologia , Mastectomia/estatística & dados numéricos , Sistema de Registros/estatística & dados numéricos , United States Department of Defense/estatística & dados numéricos , Adulto , Negro ou Afro-Americano/estatística & dados numéricos , Fatores Etários , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/terapia , Quimioterapia Adjuvante/estatística & dados numéricos , Bases de Dados Factuais/estatística & dados numéricos , Feminino , Hispânico ou Latino/estatística & dados numéricos , Humanos , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Estudos Retrospectivos , Análise de Sobrevida , Taxa de Sobrevida , Estados Unidos/epidemiologia , População Branca/estatística & dados numéricos
5.
Cochrane Database Syst Rev ; (8): CD011486, 2016 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-27541335

RESUMO

BACKGROUND: There have been enormous advances in the screening, diagnosis, intervention and overall prognosis of abdominal aortic aneurysms (AAAs) in the last decade, but despite these, ruptured AAAs (rAAAs) still cause around 3500 to 6000 deaths in England and Wales each year. Open repair remains standard treatment for rAAA in most centres but increasingly endovascular aneurysm repair (EVAR) is being adopted. This has a 30-day postoperative mortality of 40%. This has remained static despite surgical, anaesthetic and critical care advances.One significant change to current practice for elective repairs of AAAs, as opposed to emergency repairs of rAAAs, has been the introduction of intravenous heparin. This provides a protective effect against cardiac and thrombotic disease in the postoperative period. This practice has not gained widespread acceptance for emergency repairs of rAAA even though a reduction in mortality and morbidity has been demonstrated in elective repairs. OBJECTIVES: The primary objective was to assess the effect of intravenous heparin on all-cause mortality in ruptured abdominal aortic aneurysm (rAAA) management in people undergoing an emergency repair.The secondary objectives were to assess the effect of intravenous heparin in rAAA management on the incidence of general arterial disease, for example, cardiovascular, cerebral, pulmonary and renal pathologies, in people undergoing emergency repair. SEARCH METHODS: The Cochrane Vascular Information Specialist (CIS) searched the Specialised Register (December 2015). In addition the CIS searched CENTRAL;2015, Issue 11). The CIS searched clinical trials registries for details of ongoing or unpublished studies. SELECTION CRITERIA: We sought all published and unpublished randomised controlled trials (RCTs) and controlled clinical trials (CCTs) of intravenous heparin in rAAA repairs (including parallel designs). DATA COLLECTION AND ANALYSIS: Two review authors independently assessed studies identified for potential inclusion in the review. We used standard methodological procedures in accordance with the Cochrane Handbook for Systematic Review of Interventions. MAIN RESULTS: We identified no RCTs or CCTs that satisfied the inclusion criteria. AUTHORS' CONCLUSIONS: We identified no RCTs or CCTs of intravenous heparin in rAAA repairs (including parallel designs). Therefore, we were unable to assess the effect of intravenous heparin on all-cause mortality and incidence of general arterial disease, for example, cardiovascular, cerebral, pulmonary and renal pathologies in rAAA management in people undergoing an emergency repair. It is clear that an RCT is needed to address this question in rAAA management as there is no high quality evidence.


Assuntos
Anticoagulantes/administração & dosagem , Aneurisma da Aorta Abdominal/cirurgia , Ruptura Aórtica/cirurgia , Tratamento de Emergência , Heparina/administração & dosagem , Emergências , Humanos , Injeções Intravenosas , Período Intraoperatório
6.
Circulation ; 127(20): 2031-7, 2013 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-23599348

RESUMO

BACKGROUND: Acute aortic dissection is a preventable life-threatening condition. However, there have been no prospective population-based studies of incidence or outcome to inform an understanding of risk factors, strategies for prevention, or projections for future clinical service provision. METHODS AND RESULTS: We prospectively determined incidence and outcomes of all acute aortic dissections in a population of 92 728 in Oxfordshire, United Kingdom, from 2002 to 2012. Among 155 patients with 174 acute aortic events, 54 patients had 59 thoracoabdominal aortic dissections (52 incident events: 6/100 000, 95% confidence interval, 4-7; 37 Stanford type A, 15 Stanford type B; 31 men, mean age=72.0 years). Among patients with type A incident events, 18 (48.6%) died before hospital assessment (61.1% women). The 30-day fatality rate was 47.4% for patients with type A dissections who survived to hospital admission and 13.3% for patients with type B dissections, although subsequent 5-year survival rates were high (85.7% for type A; 83.3% for type B). Even though 67.3% of patients were on antihypertensive drugs, 46.0% of all patients had at least 1 systolic BP ≥180 mm Hg in their primary care records over the preceding 5 years, and the proportion of blood pressures in the hypertensive range (>140/90 mm Hg) averaged 56.0%. Premorbid blood pressure was higher in patients with type A dissections that were immediately fatal than in those who survived to admission (mean/standard deviation pre-event systolic blood pressure=151.2/19.3 versus 137.9/17.9; P<0.001). CONCLUSIONS: Uncontrolled hypertension remains the most significant treatable risk factor for acute aortic dissection. Prospective population-based ascertainment showed that hospital-based registries will underestimate not only incidence and case fatality, but also the association with premorbid hypertension.


Assuntos
Aneurisma Aórtico/epidemiologia , Aneurisma Aórtico/terapia , Dissecção Aórtica/epidemiologia , Dissecção Aórtica/terapia , Vigilância da População/métodos , Idoso , Idoso de 80 Anos ou mais , Inglaterra/epidemiologia , Feminino , Seguimentos , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento
7.
Am J Respir Crit Care Med ; 183(5): 668-74, 2011 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-20622036

RESUMO

RATIONALE: Abdominal aortic aneurysms (AAA) are associated with life-threatening complications. The likelihood that an AAA will rupture is influenced by the aneurysm diameter and its expansion rate; reasons for rapid expansion are largely unknown. OBJECTIVES: To determine the prevalence of obstructive sleep apnea (OSA) in patients with AAA, and investigate a possible association between OSA and rate of AAA expansion. METHODS: A total of 127 patients (11 females), included in an AAA surveillance program, agreed to participate and underwent a sleep study. Annual AAA expansion was determined retrospectively from available ultrasound measurements. OSA was characterized using both oxygen desaturation index (ODI) and apnea-hypopnea index (AHI). Univariate and multivariate analysis was performed to assess the effect of OSA severity on AAA expansion. MEASUREMENTS AND MAIN RESULTS: Mean age was 67.9 (SD, 6) years. Median interval between the first and last AAA measurements was 18 (range, 2-113) months. An ODI or AHI of greater than 10 was found in 40.5% and 41.5% of the patients, respectively. Patients with an ODI greater than 30 (n = 12) had a significantly faster median yearly AAA expansion rate (2.9; quartiles 2/5.7 mm/y) than patients with an ODI 0-5 (n = 47; 1.2; quartiles 0/3.1 mm/y) or 6-15 (n = 43; 1.3; quartiles 0/2.7 mm/y) (P < 0.05). In multivariate regression analysis, controlling for cardiovascular risk factors and medications, ODI greater than 30 remained an independent risk factor for AAA expansion. CONCLUSIONS: In patients with AAA, OSA is highly prevalent. Severe OSA may be a causal factor for faster AAA expansion, but this needs to be proved in a randomized controlled intervention trial.


Assuntos
Aneurisma da Aorta Abdominal/epidemiologia , Apneia Obstrutiva do Sono/epidemiologia , Adulto , Idoso , Aorta Abdominal/diagnóstico por imagem , Aneurisma da Aorta Abdominal/diagnóstico por imagem , Pesos e Medidas Corporais/métodos , Estudos de Coortes , Comorbidade , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Retrospectivos , Fatores de Risco , Índice de Gravidade de Doença , Suíça/epidemiologia , Ultrassonografia , Reino Unido/epidemiologia
8.
Transfusion ; 51(2): 242-52, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20796254

RESUMO

BACKGROUND: At major combat hospitals, the military is able to provide blood products to include apheresis platelets (aPLT), but also has extensive experience using fresh whole blood (FWB). In massively transfused trauma patients, we compared outcomes of patients receiving FWB to those receiving aPLT. STUDY DESIGN AND METHODS: This study was a retrospective review of casualties at the military hospital in Baghdad, Iraq, between January 2004 and December 2006. Patients requiring massive transfusion (≥10 units in 24 hr) were divided into two groups: those receiving FWB (n = 85) or aPLT (n = 284) during their resuscitation. Admission characteristics, resuscitation, and survival were compared between groups. Multivariate regression analyses were performed comparing survival of patients at 24 hours and at 30 days. Secondary outcomes including adverse events and causes of death were analyzed. RESULTS: Unadjusted survival between groups receiving aPLT and FWB was similar at 24 hours (84% vs. 81%, respectively; p = 0.52) and at 30 days (60% versus 57%, respectively; p = 0.72). Multivariate regression failed to identify differences in survival between patients receiving PLT transfusions either as FWB or as aPLT at 24 hours or at 30 days. CONCLUSIONS: Survival for massively transfused trauma patients receiving FWB appears to be similar to patients resuscitated with aPLT. Prospective trials will be necessary before consideration of FWB in the routine management of civilian trauma. However, in austere environments where standard blood products are unavailable, FWB is a feasible alternative.


Assuntos
Transfusão de Sangue/métodos , Medicina Militar/tendências , Guerra , Ferimentos Penetrantes/terapia , Adulto , Transfusão de Sangue/estatística & dados numéricos , Transfusão de Sangue/tendências , Embolia/etiologia , Embolia/mortalidade , Transfusão de Eritrócitos/efeitos adversos , Transfusão de Eritrócitos/estatística & dados numéricos , Exsanguinação/mortalidade , Exsanguinação/prevenção & controle , Exsanguinação/terapia , Fator VIII , Feminino , Fibrinogênio , Hospitais Militares/estatística & dados numéricos , Humanos , Infecções/etiologia , Infecções/mortalidade , Guerra do Iraque 2003-2011 , Estimativa de Kaplan-Meier , Masculino , Insuficiência de Múltiplos Órgãos/etiologia , Insuficiência de Múltiplos Órgãos/mortalidade , Transfusão de Plaquetas/efeitos adversos , Transfusão de Plaquetas/estatística & dados numéricos , Plaquetoferese , Modelos de Riscos Proporcionais , Síndrome do Desconforto Respiratório/etiologia , Síndrome do Desconforto Respiratório/mortalidade , Ressuscitação/métodos , Estudos Retrospectivos , Reação Transfusional , Índices de Gravidade do Trauma , Resultado do Tratamento , Ferimentos não Penetrantes/mortalidade , Ferimentos não Penetrantes/terapia , Ferimentos Penetrantes/mortalidade , Adulto Jovem
9.
J Trauma ; 71(1 Suppl): S82-6, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21795883

RESUMO

BACKGROUND: Studies have shown decreased mortality after improvements in combat casualty care, including increased fresh frozen plasma (FFP):red blood cell (RBC) ratios. The objective was to evaluate the evolution and impact of improved combat casualty care at different time periods of combat operations. METHODS: A retrospective review was performed at one combat support hospital in Iraq of patients requiring both massive transfusion (≥ 10 units RBC in 24 hours) and exploratory laparotomy. Patients were divided into two cohorts based on year wounded: C1 between December 2003 and June 2004, and C2 between September 2007 and May 2008. Admission data, amount of blood products and fluid transfused, and 48 hour mortality were compared. Statistical significance was set at p < 0.05. RESULTS: There was decreased mortality in C2 (47% vs. 20%). Patients arrived warmer with higher hemoglobin. They were transfused more RBC and FFP in the emergency department (5 units ± 3 units vs. 2 units ± 2 units; 3 units ± 2 units vs. 0 units ± 1 units, respectively) and received less crystalloid in operating room (3.3 L ± 2.2 L vs. 8.5 L ± 4.9 L). The FFP:RBC ratio was also closer to 1:1 in C2 (0.775 ± 0.32 vs. 0.511 ± 0.21). CONCLUSIONS: The combination of improved prehospital care, trauma systems approach, performance improvement projects, and improved transfusion or resuscitation practices have led to a 50% decrease in mortality for this critically injured population. We are now transfusing blood products in a ratio more consistent with 1 FFP to 1 RBC. Simultaneously, crystalloid use has decreased by 61%, all of which is consistent with hemostatic resuscitation principles.


Assuntos
Transfusão de Sangue , Laparotomia/métodos , Medicina Militar/métodos , Ferimentos e Lesões/cirurgia , Adulto , Transfusão de Sangue/mortalidade , Serviços Médicos de Emergência/métodos , Serviços Médicos de Emergência/normas , Humanos , Guerra do Iraque 2003-2011 , Laparotomia/normas , Medicina Militar/normas , Ressuscitação/métodos , Ressuscitação/normas , Estudos Retrospectivos , Ferimentos e Lesões/mortalidade , Ferimentos e Lesões/terapia
10.
J Trauma ; 71(2 Suppl 3): S343-52, 2011 08.
Artigo em Inglês | MEDLINE | ID: mdl-21814102

RESUMO

BACKGROUND: The effect of blood component ratios on the survival of patients with traumatic brain injury (TBI) has not been studied. METHODS: A database of patients transfused in the first 24 hours after admission for injury from 22 Level I trauma centers over an 18-month period was queried to find patients who (1) met different definitions of massive transfusion (5 units red blood cell [RBC] in 6 hours vs. 10 units RBC in 24 hours), (2) received high or low ratios of platelets or plasma to RBC units (<1:2 vs. ≥ 1:2), and (3) had severe TBI (head abbreviated injury score ≥ 3) (TBI+). RESULTS: Of 2,312 total patients, 850 patients were transfused with ≥ 5 RBC units in 6 hours and 807 could be classified into TBI+ (n = 281) or TBI- (n = 526). Six hundred forty-three patients were transfused with ≥ 10 RBC units in 24 hours with 622 classified into TBI+ (n = 220) and TBI- (n = 402). For both high-risk populations, a high ratio of platelets:RBCs (not plasma) was independently associated with improved 30-day survival for patients with TBI+ and a high ratio of plasma:RBCs (not platelets) was independently associated with improved 30-day survival in TBI- patients. CONCLUSIONS: High platelet ratio was associated with improved survival in TBI+ patients while a high plasma ratio was associated with improved survival in TBI- patients. Prospective studies of blood product ratios should include TBI in the analysis for determination of optimal use of ratios on outcome in injured patients.


Assuntos
Transfusão de Componentes Sanguíneos , Lesões Encefálicas/mortalidade , Lesões Encefálicas/terapia , Adulto , Lesões Encefálicas/sangue , Contagem de Eritrócitos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Contagem de Plaquetas , Estudos Retrospectivos , Taxa de Sobrevida , Centros de Traumatologia , Resultado do Tratamento , Adulto Jovem
11.
J Trauma ; 71(2 Suppl 3): S318-28, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21814099

RESUMO

BACKGROUND: Several recent military and civilian trauma studies demonstrate that improved outcomes are associated with early and increased use of plasma-based resuscitation strategies. However, outcomes associated with platelet transfusions are poorly characterized. We hypothesized that increased platelet:red blood cells (RBC) ratios would decrease hemorrhagic death and improve survival after massive transfusion (MT). METHODS: A transfusion database of patients transported from the scene to 22 Level I Trauma Centers over 12 months in 2005 to 2006 was reviewed. MT was defined as receiving ≥ 10 RBC units within 24 hours of admission. To mitigate survival bias, 25 patients who died within 60 minutes of arrival were excluded from analysis. Six random donor platelet units were considered equal to a single apheresis platelet unit. Admission and outcome data associated with the low (>1:20), medium (1:2), and high (1:1) platelet:RBC ratios were examined. These groups were based on the median value of the tertiles for the ratio of platelets:RBC units. RESULTS: Two thousand three hundred twelve patients received at least one unit of blood and 643 received an MT. Admission vital signs, INR, temperature, pH, Glasgow Coma Scale, Injury Severity Score, and age were similar between platelet ratio groups. The average admission platelet counts were lower in the patients who received the high platelet:RBC ratio versus the low ratio (192 vs. 216, p = 0.03). Patients who received MT were severely injured, with a mean (± standard deviation) Injury Severity Score of 33 ± 16 and received 22 ± 15 RBCs and 11 ± 14 platelets within 24 hours of injury. Increased platelet ratios were associated with improved survival at 24 hours and 30 days (p < 0.001 for both). Truncal hemorrhage as a cause of death was decreased (low: 67%, medium: 60%, high: 47%, p = 0.04). Multiple organ failure mortality was increased (low: 7%, medium: 16%, high: 27%, p = 0.003), but overall 30-day survival was improved (low: 52%, medium: 57%, high: 70%) in the high ratio group (medium vs. high: p = 0.008; low vs. high: p = 0.007). CONCLUSION: Similar to recently published military data, transfusion of platelet:RBC ratios of 1:1 was associated with improved early and late survival, decreased hemorrhagic death and a concomitant increase in multiple organ failure-related mortality. Based on this large retrospective study, increased and early use of platelets may be justified, pending the results of prospective randomized transfusion data.


Assuntos
Transfusão de Sangue , Hemorragia/sangue , Hemorragia/terapia , Ferimentos e Lesões/sangue , Ferimentos e Lesões/mortalidade , Adulto , Serviço Hospitalar de Emergência , Contagem de Eritrócitos , Feminino , Hemorragia/mortalidade , Humanos , Masculino , Pessoa de Meia-Idade , Contagem de Plaquetas , Valor Preditivo dos Testes , Estudos Retrospectivos , Taxa de Sobrevida , Resultado do Tratamento , Ferimentos e Lesões/terapia , Adulto Jovem
12.
J Exp Med ; 200(2): 169-79, 2004 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-15249592

RESUMO

Ebola virus is a highly lethal human pathogen and is rapidly driving many wild primate populations toward extinction. Several lines of evidence suggest that innate, nonspecific host factors are potentially critical for survival after Ebola virus infection. Here, we show that nonreplicating Ebola virus-like particles (VLPs), containing the glycoprotein (GP) and matrix protein virus protein (VP)40, administered 1-3 d before Ebola virus infection rapidly induced protective immunity. VLP injection enhanced the numbers of natural killer (NK) cells in lymphoid tissues. In contrast to live Ebola virus, VLP treatment of NK cells enhanced cytokine secretion and cytolytic activity against NK-sensitive targets. Unlike wild-type mice, treatment of NK-deficient or -depleted mice with VLPs had no protective effect against Ebola virus infection and NK cells treated with VLPs protected against Ebola virus infection when adoptively transferred to naive mice. The mechanism of NK cell-mediated protection clearly depended on perforin, but not interferon-gamma secretion. Particles containing only VP40 were sufficient to induce NK cell responses and provide protection from infection in the absence of the viral GP. These findings revealed a decisive role for NK cells during lethal Ebola virus infection. This work should open new doors for better understanding of Ebola virus pathogenesis and direct the development of immunotherapeutics, which target the innate immune system, for treatment of Ebola virus infection.


Assuntos
Doença pelo Vírus Ebola/imunologia , Doença pelo Vírus Ebola/prevenção & controle , Células Matadoras Naturais/metabolismo , Animais , Citocinas/biossíntese , Citotoxicidade Imunológica , Humanos , Imunoterapia/métodos , Interferon gama/metabolismo , Interleucina-2/metabolismo , Glicoproteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Microscopia de Força Atômica , Perforina , Proteínas Citotóxicas Formadoras de Poros , Baço/metabolismo , Fatores de Tempo
13.
Transfusion ; 50(6): 1227-39, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20345562

RESUMO

BACKGROUND: There is little systematically derived evidence-based guidance to inform plasma transfusion decisions. To address this issue, the AABB commissioned the development of clinical practice guidelines to help direct appropriate transfusion of plasma. STUDY DESIGN AND METHODS: A systematic review (SR) and meta-analysis of randomized and observational studies was performed to quantify known benefits and harms of plasma transfusion in common clinical scenarios (see accompanying article). A multidisciplinary guidelines panel then used the SR and the GRADE methodology to develop evidence-based plasma transfusion guidelines as well as identify areas for future investigation. RESULTS: Based on evidence ranging primarily from moderate to very low in quality, the panel developed the following guidelines: 1) The panel suggested that plasma be transfused to patients requiring massive transfusion. However, 2) the panel could not recommend for or against transfusion of plasma at a plasma : red blood cell ratio of 1:3 or more during massive transfusion, 3) nor could the panel recommend for or against transfusion of plasma to patients undergoing surgery in the absence of massive transfusion. 4) The panel suggested that plasma be transfused in patients with warfarin therapy-related intracranial hemorrhage, 5) but could not recommend for or against transfusion of plasma to reverse warfarin anticoagulation in patients without intracranial hemorrhage. 6) The panel suggested against plasma transfusion for other selected groups of patients. CONCLUSION: We have systematically developed evidence-based guidance to inform plasma transfusion decisions in common clinical scenarios. Data from additional randomized studies will be required to establish more comprehensive and definitive guidelines for plasma transfusion.


Assuntos
Transfusão de Componentes Sanguíneos/normas , Medicina Baseada em Evidências , Plasma , Anticoagulantes/efeitos adversos , Anticoagulantes/farmacologia , Transfusão de Componentes Sanguíneos/efeitos adversos , Humanos , Hemorragias Intracranianas/induzido quimicamente , Hemorragias Intracranianas/terapia , Varfarina/efeitos adversos , Varfarina/farmacologia
14.
J Trauma ; 69 Suppl 1: S123-34, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20622606

RESUMO

BACKGROUND: Popliteal artery war wounds can bleed severely and historically have high rates of amputation associated with ligation (72%) and repair (32%). More than before, casualties are now surviving the initial medical evacuation and presenting with severely injured limbs that prompt immediate limb salvage decisions in the midst of life-saving maneuvers. A modern analysis of current results may show important changes because previous limb salvage strategies were limited by the resuscitation and surgical techniques of their eras. Because exact comparisons between wars are difficult, the objective of this study was to calculate a worst-case (a pulseless, fractured limb with massive hemorrhage from popliteal artery injury) amputation-free survival rate for the most severely wounded soldiers undergoing immediate reconstruction to save both life and limb. METHODS: We performed a retrospective study of trauma casualties admitted to the combat support hospital at Ibn Sina Hospital in Baghdad, Iraq, between 2003 and 2007. US military casualties requiring a massive transfusion (> or = 10 blood units transfused within 24 hours of injury) were identified. We extracted data on the subset of casualties with a penetrating supra or infrageniculate popliteal arterial vascular injury. Demographics, injury mechanism, Injury Severity Score, tourniquet use, physiologic parameters, damage control adjuncts, surgical repair techniques, operative time, and outcomes (all-cause 30-day mortality, amputation rates, limb salvage failure, and graft patency) were investigated. RESULTS: Forty-six massively transfused male casualties, median age 24 years (range, 19-54 years; mean Injury Severity Score, 19 +/- 8.0), underwent immediate orthopedic stabilization and vascular reconstruction. There was one early death. The median operative time for the vascular repairs was 217 minutes (range, 94-630 minutes) and included all damage control procedures. Combined arterial and venous injuries occurred in 17 (37%). Ligation was performed for no arterial and 9 venous injuries. Amputations (transtibial or transfemoral) were considered limb salvage failures (14 of 48, 29.2%) and were grouped as immediate (< or = 48 hours, 5), early (>48 hours and < or = 30 days, 6), or late (>30 days, 3). Limb losses were from graft thrombosis, infection, or chronic pain. Combined arterial and venous injuries occurred in 17 (37%). Ligation was performed for no arterial and nine venous injuries. For a median follow-up (excluding death) of 48 months (range, 23-75 months), the amputation-free survival rate was 67%. CONCLUSIONS: This study, a worst-case study, showed comparable results to historical controls regarding limb salvage rates (71% for Iraq vs. 56-69% for the Vietnam War). Thirty-day survival (98%), 4-year amputation-free survival (67%), and complication-free rates (35%) fill knowledge gaps. Guidelines for managing popliteal artery injuries show promising results because current resuscitation practices and surgical care yielded similar amputation rates to prior conflicts despite more severe injuries. Significant transfusion requirements and injury severity may not indicate a life-over-limb strategy for popliteal arterial repairs. Future studies of limb salvage failures may help improve casualty care by reducing the complications that directly impact amputation-free survival.


Assuntos
Amputação Cirúrgica/estatística & dados numéricos , Transfusão de Sangue/métodos , Implante de Prótese Vascular/métodos , Traumatismos da Perna/cirurgia , Militares , Artéria Poplítea/cirurgia , Ferimentos Penetrantes/cirurgia , Adulto , Causas de Morte/tendências , Humanos , Guerra do Iraque 2003-2011 , Traumatismos da Perna/mortalidade , Masculino , Pessoa de Meia-Idade , Artéria Poplítea/lesões , Estudos Retrospectivos , Taxa de Sobrevida/tendências , Estados Unidos/epidemiologia , Ferimentos Penetrantes/mortalidade , Adulto Jovem
15.
J Trauma ; 69(2): 353-9, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20699744

RESUMO

BACKGROUND: Two prospective randomized trauma trials have shown recombinant factor VIIa (rFVIIa) to be safe and to decrease transfusion requirements. rFVIIa is presently used in 22% of massively transfused civilian trauma patients. The US Military has used rFVIIa in combat trauma patients for five years, and two small studies of massively transfused patients described an association with improved outcomes. This study was undertaken to assess how deployed physicians are using rFVIIa and its impact on casualty outcomes. METHODS: US combat casualties (n = 2,050) receiving any blood transfusion from 2003 to 2009 were reviewed to compare patients receiving rFVIIa (n = 506) with those who did not (n = 1,544). Propensity-score matching (primary analysis) and multivariable logistic regression were used to compare outcomes. Differences were determined at p < 0.05. RESULTS: Twenty-five percent of patients received rFVIIa. Significant differences were noted between groups in indices of injury severity (Injury Severity Score, Abbreviated Injury Scale score, and Glasgow Coma Scale score), admission physiology (systolic blood pressure, diastolic blood pressure, heart rate, temperature, base deficit, hemoglobin, and international normalization ratio), and use of blood products, indicating that patients treated with rFVIIa were more severely injured, in shock, and coagulopathic. For propensity-score matching, factors associated with death were used: Injury Severity Score, Glasgow Coma Scale score, heart rate, systolic blood pressure, diastolic blood pressure, Hgb, and total packed red blood cell. A total of 266 patients per group were matched; 52% of the rFVIIa group. After pairing, there were no significant differences in any of the demographics, including incidence of massive transfusion (53% vs. 51%). There was no difference in the rate of complications (21% vs. 21%) or mortality (14% vs. 20%) for patients not treated or receiving rFVIIa, respectively. CONCLUSION: In military casualties, rFVIIa is used in the most severely injured patients based on physician selection rather than on guideline criteria. Use of rFVIIa is not associated with an improvement in survival or an increase in complications. The undetected bias of physician selection of patients for treatment with rFVIIa, likely, has an impact on case matching to achieve equivalence similar to that of randomized control studies. This inability to match populations, thus, prevents definitive interpretation of this study and others studies of similar design. This problem emphasizes the need to develop entry criteria to identify patients who could potentially benefit from use of rFVIIa and the need to subsequently perform efficacy studies.


Assuntos
Transfusão de Sangue/estatística & dados numéricos , Fator VIIa/uso terapêutico , Medicina Militar/métodos , Guerra , Ferimentos e Lesões/terapia , Transfusão de Sangue/métodos , Causas de Morte , Estudos de Coortes , Feminino , Escala de Coma de Glasgow , Humanos , Escala de Gravidade do Ferimento , Modelos Logísticos , Masculino , Militares , Análise Multivariada , Prognóstico , Curva ROC , Proteínas Recombinantes/uso terapêutico , Estudos Retrospectivos , Medição de Risco , Análise de Sobrevida , Resultado do Tratamento , Estados Unidos , Ferimentos e Lesões/etiologia , Ferimentos e Lesões/mortalidade
16.
J Trauma ; 66(4 Suppl): S69-76, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19359973

RESUMO

BACKGROUND: Increased understanding of the pathophysiology of the acute coagulopathy of trauma has lead many to question the current transfusion approach to hemorrhagic shock. We hypothesized that warm fresh whole blood (WFWB) transfusion would be associated with improved survival in patients with trauma compared with those transfused only stored component therapy (CT). METHODS: We retrospectively studied US Military combat casualty patients transfused >or=1 unit of red blood cells (RBCs). The following two groups of patients were compared: (1) WFWB, who were transfused WFWB, RBCs, and plasma but not apheresis platelets and (2) CT, who were transfused RBC, plasma, and apheresis platelets but not WFWB. The primary outcomes were 24-hour and 30-day survival. RESULTS: Of 354 patients analyzed there were 100 in the WFWB and 254 in the CT group. Patients in both groups had similar severity of injury determined by admission eye, verbal, and motor Glasgow Coma Score, base deficit, international normalized ratio, hemoglobin, systolic blood pressure, and injury severity score. Both 24-hour and 30-day survival were higher in the WFWB cohort compared with CT patients, 96 of 100 (96%) versus 223 of 254 (88%), (p = 0.018) and 95% to 82%, (p = 0.002), respectively. An increased amount (825 mL) of additives and anticoagulants were administered to the CT compared with the WFWB group, (p < 0.001). Upon multivariate logistic regression the use of WFWB and the volume of WFWB transfused was independently associated with improved 30-day survival. CONCLUSIONS: In patients with trauma with hemorrhagic shock, resuscitation strategies that include WFWB may improve 30-day survival, and may be a result of less anticoagulants and additives with WFWB use in this population.


Assuntos
Transfusão de Sangue , Militares , Choque Hemorrágico/terapia , Centros de Traumatologia , Adulto , Campanha Afegã de 2001- , Transfusão de Componentes Sanguíneos , Humanos , Guerra do Iraque 2003-2011 , Estimativa de Kaplan-Meier , Estudos Retrospectivos , Choque Hemorrágico/etiologia , Ferimentos Penetrantes/complicações , Adulto Jovem
17.
J Trauma ; 66(4 Suppl): S77-84; discussion S84-5, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19359974

RESUMO

INTRODUCTION: Trauma is a major cause of morbidity and mortality worldwide. Of patients arriving to trauma centers, patients requiring massive transfusion (MT, >or=10 units in 24 hours) are a small patient subset but are at the highest risk of mortality. Transfusion of appropriate ratios of blood products to such patients has recently been an area of interest to both the civilian and military medical community. Plasma is increasingly recognized as a critical component, though less is known about appropriate ratios of platelets. Combat casualties managed at the busiest combat hospital in Iraq provided an opportunity to examine this question. METHODS: In-patient records for 8,618 trauma casualties treated at the military hospital in Baghdad more than a 3-year interval between January 2004 and December 2006 were retrospectively reviewed and patients requiring MT (n = 694) were identified. Patients who required MT in the first 24 hours and did not receive fresh whole blood were divided into study groups defined by source of platelets: (1) patient receiving a low ratio of platelets (<1:16 apheresis platelets per stored red cell unit, aPLT:RBC) (n = 214), (2) patients receiving a medium ratio of platelets (1:16 to <1:8 aPLT:RBC) (n = 154), and (3) patients receiving a high ratio of platelets (>or=1:8 aPLT:RBC) (n = 96). The primary endpoint was survival at 24 hours and at 30 days. RESULTS: At 24 hours, patients receiving a high ratio of platelets had higher survival (95%) as compared with patients receiving a medium ratio (87%) and patients receiving the lowest ratio of platelets (64%) (log-rank p = 0.04 and p < 0.001, respectively). The survival benefit for the high and medium ratio groups remained at 30 days as compared with those receiving the lowest ratio of platelets (75% and 60% vs. 43%, p < 0.001 for both comparisons). On multivariate regression, plasma:RBC ratios and aPLT:RBC were both independently associated with improved survival at 24 hours and at 30 days. CONCLUSION: Transfusion of a ratio of >or=1:8 aPLT:RBC is associated with improved survival at 24 hours and at 30 days in combat casualties requiring a MT within 24 hours of injury. Although prospective study is needed to confirm this finding, MT protocols outside of investigational research should consider incorporation of appropriate ratios of both plasma and platelets.


Assuntos
Militares , Transfusão de Plaquetas , Choque Hemorrágico/terapia , Adulto , Transfusão de Eritrócitos , Feminino , Hospitais Militares , Humanos , Guerra do Iraque 2003-2011 , Estimativa de Kaplan-Meier , Masculino , Estudos Retrospectivos , Choque Hemorrágico/etiologia , Centros de Traumatologia , Ferimentos Penetrantes/complicações , Adulto Jovem
18.
Ann Surg ; 248(3): 447-58, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18791365

RESUMO

OBJECTIVE: To determine the effect of blood component ratios in massive transfusion (MT), we hypothesized that increased use of plasma and platelet to red blood cell (RBC) ratios would result in decreased early hemorrhagic death and this benefit would be sustained over the ensuing hospitalization. SUMMARY BACKGROUND DATA: Civilian guidelines for massive transfusion (MT > or =10 units of RBC in 24 hours) have typically recommend a 1:3 ratio of plasma:RBC, whereas optimal platelet:RBC ratios are unknown. Conversely, military data shows that a plasma:RBC ratio approaching 1:1 improves long term outcomes in MT combat casualties. There is little consensus on optimal platelet transfusions in either civilian or military practice. At present, the optimal combinations of plasma, platelet, and RBCs for MT in civilian patients is unclear. METHODS: Records of 467 MT trauma patients transported from the scene to 16 level 1 trauma centers between July 2005 and June 2006 were reviewed. One patient who died within 30 minutes of admission was excluded. Based on high and low plasma and platelet to RBC ratios, 4 groups were analyzed. RESULTS: Among 466 MT patients, survival varied by center from 41% to 74%. Mean injury severity score varied by center from 22 to 40; the average of the center means was 33. The plasma:RBC ratio ranged from 0 to 2.89 (mean +/- SD: 0.56 +/- 0.35) and the platelets:RBC ratio ranged from 0 to 2.5 (0.55 +/- 0.50). Plasma and platelet to RBC ratios and injury severity score were predictors of death at 6 hours, 24 hours, and 30 days in multivariate logistic models. Thirty-day survival was increased in patients with high plasma:RBC ratio (> or =1:2) relative to those with low plasma:RBC ratio (<1:2) (low: 40.4% vs. high: 59.6%, P < 0.01). Similarly, 30-day survival was increased in patients with high platelet:RBC ratio (> or =1:2) relative to those with low platelet:RBC ratio (<1:2) (low: 40.1% vs. high: 59.9%, P < 0.01). The combination of high plasma and high platelet to RBC ratios were associated with decreased truncal hemorrhage, increased 6-hour, 24-hour, and 30-day survival, and increased intensive care unit, ventilator, and hospital-free days (P < 0.05), with no change in multiple organ failure deaths. Statistical modeling indicated that a clinical guideline with mean plasma:RBC ratio equal to 1:1 would encompass 98% of patients within the optimal 1:2 ratio. CONCLUSIONS: Current transfusion practices and survival rates of MT patients vary widely among trauma centers. Conventional MT guidelines may underestimate the optimal plasma and platelet to RBC ratios. Survival in civilian MT patients is associated with increased plasma and platelet ratios. Massive transfusion practice guidelines should aim for a 1:1:1 ratio of plasma:platelets:RBCs.


Assuntos
Transfusão de Componentes Sanguíneos/métodos , Transfusão de Eritrócitos , Hemorragia/mortalidade , Hemorragia/terapia , Plasma , Transfusão de Plaquetas , Ferimentos e Lesões/mortalidade , Ferimentos e Lesões/terapia , Adulto , Feminino , Hemorragia/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Análise de Sobrevida , Centros de Traumatologia , Ferimentos e Lesões/complicações
19.
Crit Care Med ; 36(7 Suppl): S325-39, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18594260

RESUMO

BACKGROUND: Hemorrhage in trauma is a significant challenge, accounting for 30% to 40% of all fatalities, second only to central nervous system injury as a cause of death. However, hemorrhagic death is the leading preventable cause of mortality in combat casualties and typically occurs within 6 to 24 hrs of injury. In cases of severe hemorrhage, massive transfusion may be required to replace more than the entire blood volume. Early prediction of massive transfusion requirements, using clinical and laboratory parameters, combined with aggressive management of hemorrhage by surgical and nonsurgical means, has significant potential to reduce early mortality. DISCUSSION: Although the classification of massive transfusion varies, the most frequently used definition is ten or more units of blood in 24 hrs. Transfusion of red blood cells is intended to restore blood volume, tissue perfusion, and oxygen-carrying capacity; platelets, plasma, and cryoprecipitate are intended to facilitate hemostasis through prevention or treatment of coagulopathy. Massive transfusion is uncommon in civilian trauma, occurring in only 1% to 3% of trauma admissions. As a result of a higher proportion of penetrating injury in combat casualties, it has occurred in approximately 8% of Operation Iraqi Freedom admissions and in as many as 16% during the Vietnam conflict. Despite its potential to reduce early mortality, massive transfusion is not without risk. It requires extensive blood-banking resources and is associated with high mortality. SUMMARY: This review describes the clinical problems associated with massive transfusion and surveys the nonsurgical management of hemorrhage, including transfusion of blood products, use of hemostatic bandages/agents, and treatment with hemostatic medications.


Assuntos
Transfusão de Sangue/métodos , Cuidados Críticos/organização & administração , Hemorragia/terapia , Hemostáticos/uso terapêutico , Medicina Militar/organização & administração , Ferimentos e Lesões/complicações , Acidose/etiologia , Antifibrinolíticos/uso terapêutico , Bandagens , Transtornos da Coagulação Sanguínea/etiologia , Causas de Morte , Desamino Arginina Vasopressina/uso terapêutico , Fator VIII/uso terapêutico , Fator VIIa/uso terapêutico , Fibrinogênio/uso terapêutico , Hemorragia/etiologia , Hemorragia/mortalidade , Hemostáticos/efeitos adversos , Humanos , Hiperpotassemia/etiologia , Hipocalcemia/etiologia , Hipotermia/etiologia , Proteínas Recombinantes/uso terapêutico , Ressuscitação/efeitos adversos , Ressuscitação/métodos , Fatores de Risco , Reação Transfusional , Estados Unidos/epidemiologia , Zeolitas/uso terapêutico
20.
J Trauma ; 64(2): 286-93; discussion 293-4, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18301188

RESUMO

BACKGROUND: The majority of patients with potentially survivable combat-related injuries die from hemorrhage. Our objective was to determine whether the use of recombinant activated factor VII (rFVIIa) decreased mortality in combat casualties with severe trauma who received massive transfusions and if its use was associated with increased severe thrombotic events. METHODS: We retrospectively reviewed a database of combat casualty patients with severe trauma (Injury Severity Score [ISS] >15) and massive transfusion (red blood cell [RBCs] >/=10 units/24 hours) admitted to one combat support hospital in Baghdad, Iraq, between December 2003 and October 2005. Admission vital signs and laboratory data, blood products, ISS, 24-hour and 30-day mortality, and severe thrombotic events were compared between patients who received rFVIIa (rFVIIa) and did not receive rFVIIa (rFVIIa). RESULTS: Of 124 patients in this study, 49 patients received rFVIIa and 75 did not. ISS, laboratory values, and admission vitals did not differ between rFVIIa and rFVIIa groups, except for systolic blood pressure (mm Hg) 105 +/- 33 and 92 +/- 28, p = 0.02 and temperature ( degrees F) 96.3 +/- 2.1 and 95.2 +/- 2.4, p = 0.03, respectively. Interactions between all vital signs and laboratory values measured upon admission, to include systolic blood pressure and temperature, were not significant when measured between rFVIIa use and 30-day mortality. Twenty-four-hour mortality was 7 of 49 (14%) in rFVIIa and 26 of 75 (35%) in rFVIIa, (p = 0.01); 30-day mortality was 15 of 49 (31%) and 38 of 75 (51%), (p = 0.03). Death from hemorrhage was 8 of 14 (57%) for rFVIIa patients compared with 29 of 37 (78%) for rFVIIa patients, (p = 0.12). The incidence of severe thrombotic events was similar in both groups. CONCLUSIONS: The early use of rFVIIa was associated with decreased 30-day mortality in severely injured combat casualties requiring massive transfusion, but was not associated with increased risk of severe thrombotic events.


Assuntos
Transfusão de Sangue , Fator VIIa/uso terapêutico , Hemorragia/tratamento farmacológico , Militares , Ferimentos e Lesões/mortalidade , Causas de Morte , Bases de Dados Factuais , Fator VIIa/efeitos adversos , Hemorragia/etiologia , Humanos , Escala de Gravidade do Ferimento , Estimativa de Kaplan-Meier , Medicina Militar , Proteínas Recombinantes/efeitos adversos , Proteínas Recombinantes/uso terapêutico , Estudos Retrospectivos , Trombose/etiologia , Estados Unidos , Guerra , Ferimentos e Lesões/classificação , Ferimentos e Lesões/terapia
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa