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1.
Am J Clin Pathol ; 159(1): 81-88, 2023 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-36315019

RESUMO

OBJECTIVES: Present-day pathologists may be unfamiliar with the histopathologic features of measles, which is a reemerging disease. Awareness of these features may enable early diagnosis of measles in unsuspected cases, including those with an atypical presentation. Using archived tissue samples from historic patients, a unique source of histopathologic information about measles and other reemerging infectious diseases, we performed a comprehensive analysis of the histopathologic features of measles seen in commonly infected tissues during prodrome, active, and late phases of the disease. METHODS: Subspecialty pathologists analyzed H&E-stained slides of specimens from 89 patients accessioned from 1919 to 1998 and correlated the histopathologic findings with clinical data. RESULTS: Measles caused acute and chronic histopathologic changes, especially in the respiratory, lymphoid (including appendix and tonsils), and central nervous systems. Bacterial infections in lung and other organs contributed significantly to adverse outcomes, especially in immunocompromised patients. CONCLUSIONS: Certain histopathologic features, especially Warthin-Finkeldey cells and multinucleated giant cells without inclusions, allow pathologists to diagnose or suggest the diagnosis of measles in unsuspected cases.


Assuntos
Sarampo , Humanos , Sarampo/diagnóstico , Sarampo/microbiologia , Sarampo/patologia , Pulmão/patologia , Células Gigantes/patologia , Corpos de Inclusão/patologia
2.
Mil Med ; 185(9-10): e1654-e1661, 2020 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-32648931

RESUMO

INTRODUCTION: Knowledge of the contemporary epidemiology of hepatitis B virus (HBV) infection among military personnel can inform potential Department of Defense (DoD) screening policy and infection and disease control strategies. MATERIALS AND METHODS: HBV infection status at accession and following deployment was determined by evaluating reposed serum from 10,000 service members recently deployed to combat operations in Iraq and Afghanistan in the period from 2007 to 2010. A cost model was developed from the perspective of the Department of Defense for a program to integrate HBV infection screening of applicants for military service into the existing screening program of screening new accessions for vaccine-preventable infections. RESULTS: The prevalence of chronic HBV infection at accession was 2.3/1,000 (95% CI: 1.4, 3.2); most cases (16/21, 76%) identified after deployment were present at accession. There were 110 military service-related HBV infections identified. Screening accessions who are identified as HBV susceptible with HBV surface antigen followed by HBV surface antigen neutralization for confirmation offered no cost advantage over not screening and resulted in a net annual increase in cost of $5.78 million. However, screening would exclude as many as 514 HBV cases each year from accession. CONCLUSIONS: Screening for HBV infection at service entry would potentially reduce chronic HBV infection in the force, decrease the threat of transfusion-transmitted HBV infection in the battlefield blood supply, and lead to earlier diagnosis and linkage to care; however, applicant screening is not cost saving. Service-related incident infections indicate a durable threat, the need for improved laboratory-based surveillance tools, and mandate review of immunization policy and practice.


Assuntos
Hepatite B , Militares , Adulto , Afeganistão , Feminino , Hepatite B/diagnóstico , Hepatite B/epidemiologia , Humanos , Iraque , Masculino , Programas de Rastreamento , Prevalência , Estudos Soroepidemiológicos
3.
Hepatology ; 63(2): 398-407, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26481723

RESUMO

UNLABELLED: Knowledge of the contemporary epidemiology of hepatitis C viral (HCV) infection among military personnel can inform potential Department of Defense screening policy. HCV infection status at the time of accession and following deployment was determined by evaluating reposed serum from 10,000 service members recently deployed to combat operations in Iraq and Afghanistan in the period 2007-2010. A cost model was developed from the perspective of the Department of Defense for a military applicant screening program. Return on investment was based on comparison between screening program costs and potential treatment costs avoided. The prevalence of HCV antibody-positive and chronic HCV infection at accession among younger recently deployed military personnel born after 1965 was 0.98/1000 (95% confidence interval 0.45-1.85) and 0.43/1000 (95% confidence interval 0.12-1.11), respectively. Among these, service-related incidence was low; 64% of infections were present at the time of accession. With no screening, the cost to the Department of Defense of treating the estimated 93 cases of chronic HCV cases from a single year's accession cohort was $9.3 million. Screening with the HCV antibody test followed by the nucleic acid test for confirmation yielded a net annual savings and a $3.1 million dollar advantage over not screening. CONCLUSIONS: Applicant screening will reduce chronic HCV infection in the force, result in a small system costs savings, and decrease the threat of transfusion-transmitted HCV infection in the battlefield blood supply and may lead to earlier diagnosis and linkage to care; initiation of an applicant screening program will require ongoing evaluation that considers changes in the treatment cost and practice landscape, screening options, and the epidemiology of HCV in the applicant/accession and overall force populations.


Assuntos
Custos de Cuidados de Saúde , Hepatite C Crônica/economia , Hepatite C Crônica/epidemiologia , Militares , Adulto , Feminino , Anticorpos Anti-Hepatite C/sangue , Hepatite C Crônica/sangue , Humanos , Masculino , Estudos Soroepidemiológicos , Adulto Jovem
5.
Transfusion ; 53(10): 2176-82, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23362944

RESUMO

BACKGROUND: The United States introduced human T-lymphotropic virus Type I (HTLV-I) screening of blood donors in 1988. The US military uses freshly collected blood products for life-threatening injuries when available stored blood components in theater have been exhausted or when these components are unsuccessful for resuscitation. These donors are screened after donation by the Department of Defense (DoD) retrospective testing program. All recipients of blood collected in combat are tested according to policy soon after and at 3, 6, and 12 months after transfusion. CASE REPORT: A 31-year-old US Army soldier tested positive for HTLV-I 44 days after receipt of emergency blood transfusions for severe improvised explosive device blast injuries. One donor's unit tested HTLV-I positive on the DoD-mandated retrospective testing. Both the donor and the recipient tested reactive with enzyme immunoassay and supplemental confirmation by HTLV-I Western blot. The donor and recipient reported no major risk factors for HTLV-I. Phylogenetic analysis of HTLV-I sequences indicated Cosmopolitan subtype, Subgroup B infections. Comparison of long terminal repeat and env sequences revealed molecular genetic linkage of the viruses from the donor and recipient. CONCLUSION: This case is the first report of transfusion transmission of HTLV-I in the US military during combat operations. The emergency fresh whole blood policy enabled both the donor and the recipient to be notified of their HTLV-I infection. While difficult in combat, predonation screening of potential emergency blood donors with Food and Drug Administration-mandated infectious disease testing as stated by the DoD Health Affairs policy should be the goal of every facility engaged with emergency blood collection in theater.


Assuntos
Infecções por HTLV-I/transmissão , Reação Transfusional , Adulto , Emergências , Vírus Linfotrópico T Tipo 1 Humano/classificação , Vírus Linfotrópico T Tipo 1 Humano/genética , Humanos , Masculino , Militares , Filogenia
6.
Transfusion ; 53 Suppl 1: 9S-16S, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23301981

RESUMO

Damage control resuscitation (DCR) is emerging as a standard practice in civilian and military trauma care. Primary objectives include resolution of immediate life threats followed by optimization of physiological status in the perioperative period. To accomplish this, DCR employs a unique hypotensive-hemostatic resuscitation strategy that avoids traditional crystalloid intravenous fluids in favor of early blood component use in ratios mimicking whole blood. The presence of uncontrolled major hemorrhage (UMH) coupled with a delay in access to hemostatic surgical intervention remains a primary contributor to preventable death in both combat and in many domestic settings, including rural areas and disaster sites. As a result, civilian and military emergency care leaders throughout the world have sought a means to project DCR principles forward of the traditional trauma resuscitation bay, into such remote environments as disaster scenes, rural health facilities, and the contemporary battlefield. After reflecting on experiences from past conflicts, defining current capability gaps, and examining available and potential solutions, a strategy for "remote damage control resuscitation" (RDCR) has been proposed. In order for RDCR to progress from concept to clinical strategy, it will be necessary to define existing gaps in knowledge and clinical capability; develop a lexicon so that investigators and operators may understand each other; establish coherent research and development agendas; and execute comprehensive investigations designed to predict, diagnose, and mitigate the consequences of hemorrhagic shock and acute traumatic coagulopathy before they become irreversible. This article seeks to introduce the concept of RDCR; to reinforce the importance of identifying and optimally managing UMH and the resulting shock state as part of a comprehensive approach to out-of-hospital stabilization and en route care; and to propose investigational strategies to enable the development and broad implementation of RDCR principles.


Assuntos
Transfusão de Componentes Sanguíneos/métodos , Planejamento em Desastres/métodos , Avaliação das Necessidades , Ressuscitação/métodos , Ferimentos e Lesões/terapia , Transfusão de Componentes Sanguíneos/tendências , Congressos como Assunto , Planejamento em Desastres/tendências , Humanos , Medicina Militar/métodos , Medicina Militar/tendências , Ressuscitação/tendências , Choque Hemorrágico/terapia
7.
Transfusion ; 53(1): 69-75, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22554200

RESUMO

BACKGROUND: The purpose of this study was to assess functionality and resources of facilities providing blood collection and transfusion services in Afghanistan. STUDY DESIGN AND METHODS: This national cross-sectional assessment included facilities collecting or transfusing blood identified through official data sources and private key informants. At each facility, study representatives completed a standardized instrument assessing presence of records logbook, electricity, refrigeration, and required transfusion-transmitted infection (TTI; human immunodeficiency virus, syphilis, and hepatitis B and C) test kits. Descriptive statistics were generated, with differences analyzed using chi-square or Fisher's exact tests. RESULTS: Between August and November 2010, a total of 243 facilities were surveyed with public (52.3%, n = 127) and private (43.2%, n = 105) sector comprising the majority. Most (63%) facilities were urban, with 23.5% located in Kabul province. Of 92,682 units collected nationally in the 12 months before evaluation, 7.5% (n = 6952) had no disposition record. Many (62%, n = 151) facilities had an established recordkeeping system; the remainder provided estimates. Half of surveyed facilities had regular power supply (57.8%), refrigerators for storing blood (52.3%), or all necessary TTI test kits (62.1%). Military (83.3%) and public (74.8%) facilities were more likely to have all TTI test kits present compared to private (46.7%, p < 0.01) but not nongovernmental organization (40.0%, p = 0.37) facilities. CONCLUSION: In Afghanistan, blood donation and transfusion occur with substantial differences in data recording and TTI test availability, with private facilities less likely to have these resources. Efforts are needed to improve available resources and ensure that facilities are in compliance with national standards for donor screening.


Assuntos
Doadores de Sangue , Transfusão de Sangue , Serviços de Saúde/estatística & dados numéricos , Afeganistão , Estudos Transversais , Humanos
8.
Transfusion ; 53(3): 505-17, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22823283

RESUMO

BACKGROUND: Emergency whole blood transfusion is a lifesaving procedure employed on modern battlefields. Rapid device tests (RDTs) are frequently used to mitigate transfusion-transmitted infection risks. STUDY DESIGN AND METHODS: A limited evaluation of the RDT formerly used on battlefields was performed using 50 donor plasma samples and commercially available panels. Five hepatitis C virus (HCV) RDTs with sufficient stated sensitivity and thermostability were assessed using 335 HCV-positive and 339 HCV-negative donor plasma samples, 54 seroconversion panel plasma samples, and 84 HCV-positive and 84 HCV-negative spiked whole blood under normal, hot, and cold storage conditions and normal and hot test conditions, plus an ease-of-use survey. RESULTS: BioRapid HCV test sensitivity on donor plasma was 84% (95% confidence interval [CI], 70.9%-92.8%). Using all positive plasma samples, OraQuick HCV sensitivity exceeded all comparators (99.4%, 95% CI, 98.0%-99.9%, p<0.05). Specificity was consistently high, led by OraQuick HCV at 99.7% (95% CI, 98.6%-100%), statistically superior only to Axiom HCV (p<0.05). Using seroconversion panels, only OraQuick HCV showed equivalent or earlier HCV detection compared to the gold standard. Using spiked whole blood, specificity was consistently high, and sensitivity ranged significantly from 34.5% (95% CI, 25.0%-45.1%) for CORE HCV to 98.8% (95% CI, 94.3%-99.9%) for OraQuick HCV. All comparator RDTs were significantly less sensitive than OraQuick HCV at one or more stress condition. CONCLUSION: This HCV RDT comparison identified significant sensitivity differences, particularly using whole blood under extreme storage and testing conditions. These data support OraQuick HCV superiority and illustrate the value of RDT evaluation under simulated field conditions.


Assuntos
Doadores de Sangue , Seleção do Doador/métodos , Serviços Médicos de Emergência , Anticorpos Anti-Hepatite C/sangue , Kit de Reagentes para Diagnóstico , Algoritmos , Doadores de Sangue/estatística & dados numéricos , Preservação de Sangue/métodos , Segurança do Sangue , Técnicas de Laboratório Clínico/instrumentação , Técnicas de Laboratório Clínico/métodos , Eficiência , Serviços Médicos de Emergência/métodos , Serviços Médicos de Emergência/normas , Hepatite C/sangue , Hepatite C/diagnóstico , Anticorpos Anti-Hepatite C/análise , Humanos , Kit de Reagentes para Diagnóstico/normas , Sensibilidade e Especificidade , Fatores de Tempo
9.
Transfusion ; 53(9): 2061-8, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23216410

RESUMO

BACKGROUND: Little information is available regarding blood supply safety in Afghanistan. The purpose of this study was to assess blood safety through serologic and observational measures in Afghanistan. STUDY DESIGN AND METHODS: This cross-sectional assessment included the 40 highest-volume facilities collecting and transfusing blood nationally identified in a previous survey. At each facility, study representatives completed a standardized instrument assessing staff performance of transfusion-related activities and performed rapid testing for human immunodeficiency virus, syphilis, and hepatitis B and C with rapid diagnostic tests on clinically discarded specimens. Reactive samples received confirmatory testing. Descriptive statistics were generated, with differences analyzed using chi-square or Fisher's exact tests. RESULTS: Between November 2010 and May 2011, a total of 332 blood donor collection procedures were observed. Only 52.4% of observed encounters correctly screened and deferred donors by international criteria. Public and private facilities demonstrated glove use, proper sharps disposal, and patient counseling and relayed screening test results in less than 75% of observed events, significantly less likely than military facilities (p < 0.01). Of 1612 specimens assessed, confirmed cases of hepatitis B (n = 6), hepatitis C (n = 1), and syphilis (n = 3) were detected among units already prescreened and accepted for transfusion. CONCLUSION: Lapses in proper donor screening contributed to the presence of confirmed-positive units available for transfusion, as detected in this study. Steps must be taken to ensure standardization of testing kits requirements, documentation, and mandatory training and continuing education for blood bank staff with regard to counseling, drawing, processing, and transfusion of blood products.


Assuntos
Armazenamento de Sangue/métodos , Bancos de Sangue/normas , Seleção do Doador/métodos , Seleção do Doador/normas , Afeganistão , Doadores de Sangue , Segurança do Sangue , Estudos Transversais , Humanos
11.
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
12.
Transfusion ; 51(3): 473-85, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20946199

RESUMO

BACKGROUND: Current US military clinical practice guidelines permit emergency transfusions of non-Food and Drug Administration (FDA)-compliant freshly collected blood products in theaters of war. This investigation aimed to characterize the risks of transfusion-transmitted infections (TTIs) associated with battlefield transfusions of non-FDA-compliant blood products. STUDY DESIGN AND METHODS: US Service members who received emergency transfusion products in Iraq and Afghanistan (March 1, 2002-September 30, 2007) were tested for hepatitis C virus (HCV), human immunodeficiency virus (HIV), and hepatitis B virus (HBV) infections using reposed pre- and posttransfusion sera. Selected regions of viral genomes from epidemiologically linked infected recipients and their donors were sequenced and compared. RESULTS: Of 761 US Service members who received emergency transfusion products, 475 were tested for HCV, 472 for HIV, and 469 for HBV. One transfusion-transmitted HCV infection (incidence rate of 2.1/1000 persons) was identified. The pretransfusion numbers (prevalence per 1000 persons) were HCV-four (8/1000), HIV-zero (0/1000), chronic HBV-two (4 /1000), and naturally immune (antibody to HBV core antigen)-nine (19/1000). CONCLUSION: One HCV TTI was determined to be associated with emergency blood product use. The pretransfusion HCV and HBV prevalence in transfusion recipients, themselves members of the potential donor population, indicates better characterization of the deployed force's actual donor population, and further investigations of the TTI prevalence in these donors are needed. These data will inform countermeasure development and clinical decision making.


Assuntos
Guerra do Iraque 2003-2011 , Militares , Transfusão de Plaquetas/efeitos adversos , Reação Transfusional , Viroses/transmissão , Adulto , Idoso , Sequência de Bases , Feminino , Infecções por HIV/epidemiologia , Infecções por HIV/transmissão , Hepatite B/epidemiologia , Hepatite B/transmissão , Hepatite C/epidemiologia , Hepatite C/transmissão , Humanos , Iraque/epidemiologia , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Viroses/epidemiologia
14.
Mol Microbiol ; 69(5): 1180-90, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18627466

RESUMO

Most tailed bacteriophages and herpes viruses replicate genome as a concatemer which is cut by a 'headful' nuclease upon completion of genome packaging. Here, the catalytic centre of phage T4 headful nuclease, present in the C-terminal domain of 'large terminase' gp17, has been defined by mutational, biochemical and structural analyses. The crystal structure shows that this nuclease has an RNase-H fold, suggesting that it cuts DNA by a two-metal ion mechanism. The active centre has a Mg ion co-ordinated by three acidic residues, D401, E458 and D542. Mutations at any of these residues resulted in loss of nuclease activity, but the mutants can package linear DNA. The gp17's nuclease activity is modulated by the 'small terminase', gp16, by the N-terminal ATPase domain of gp17, and by the assembled packaging motor. These results lead to hypotheses concerning how phage headful nucleases cut the viral genomes before and after, but not during, DNA packaging.


Assuntos
Bacteriófago T4/enzimologia , Bacteriófago T4/fisiologia , Empacotamento do DNA , Desoxirribonucleases/metabolismo , Proteínas Virais/metabolismo , Adenosina Trifosfatases/genética , Adenosina Trifosfatases/metabolismo , Sequência de Aminoácidos , Bacteriófago T4/química , Bacteriófago T4/genética , Bacteriófagos/genética , DNA Viral/genética , Desoxirribonucleases/química , Desoxirribonucleases/genética , Modelos Moleculares , Dados de Sequência Molecular , Estrutura Terciária de Proteína , Alinhamento de Sequência , Proteínas Virais/química , Proteínas Virais/genética , Montagem de Vírus
15.
Transfusion ; 46(7): 1178-83, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16836565

RESUMO

BACKGROUND: An automated cell processing system (ACP 215, Haemonetics Corp.) can be used for the glycerolization and deglycerolization of RBC components, but the components must be 6 or fewer days old. Depending on the anticoagulant (CP2D)/additive solution (AS) used, deglycerolized RBCs can be stored at 1 to 6 degrees C for up to 14 days. This study evaluated in vitro variables of apheresis RBC stored for 6 and 14 days at 1 to 6 degrees C before glycerolization and 14 days after deglycerolization. STUDY DESIGN AND METHODS: Two units of CP2D/AS-3 leukoreduced RBCs were collected by apheresis from seven donors. One unit was glycerolized and frozen 6 days and the other 14 days after collection. All units were deglycerolized with the ACP 215 and stored at 1 to 6 degrees C for 14 days in AS-3. Several in vitro variables were evaluated during postdeglycerolization storage. RESULTS: All components had postdeglycerolization RBC recoveries greater than 81 percent and osmolalities of less than 400 mOsm per kg. No significant differences were noted in potassium and supernatant hemoglobin after 14 days of postdeglycerolization storage between RBCs frozen at 6 and 14 days after collection. After 14 days of postdeglycerolization storage, however, the pH, lactate, and ATP levels were slightly lower in RBCs frozen after 14 days. CONCLUSION: The ACP 215 can be used to glycerolize and deglycerolize apheresis RBC components that are up to 14 days of age. It is likely that apheresis components glycerolized at 14 days of age or less can be stored up to 14 days in AS-3 after deglycerolization, but this should be confirmed with in vivo survival studies.


Assuntos
Remoção de Componentes Sanguíneos/normas , Transfusão de Eritrócitos/normas , Trifosfato de Adenosina/análise , Remoção de Componentes Sanguíneos/métodos , Preservação de Sangue/normas , Criopreservação , Eritrócitos , Glicerol , Humanos , Concentração de Íons de Hidrogênio , Lactatos/análise , Concentração Osmolar , Fatores de Tempo
16.
Transfusion ; 44(2): 210-6, 2004 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-14962312

RESUMO

BACKGROUND: There is a universal need, in both civilian and military settings, for a lightweight container capable of maintaining RBCs at 1 to 10 degrees C in remote areas, during extended transit times, and under austere environments. The use of ice in insulated containers or small commercial coolers for these purposes often results in loss of RBCs due to failure to maintain temperatures within the requisite range. A lightweight and thermally efficient container capable of carrying 4 to 6 units of RBCs at 1 to 10 degrees C for over 72 hours under extreme conditions would help resolve current problems in RBC transportation. STUDY DESIGN AND METHODS: Six different prototype containers incorporating phase-change materials (PCMs) in their designs were evaluated for their ability to maintain RBCs between 1 and 10 degrees C while exposed to external temperatures of -24 degrees C and 40 degrees C. In separate experiments, a container was opened and a RBC unit removed. RESULTS: One container weighing 10 pounds with four units of RBCs was capable of maintaining the temperature of the units between 1 and 10 degrees C for over 78 hours, 96 hours, and 120 hours at 40 degrees C, -24 degrees C, and 23 degrees C, respectively. Opening the container decreased these times by 2 to 3 hours. CONCLUSIONS: An energy-efficient and lightweight container that maintains RBCs at 1 to 10 degrees C under austere environments for over 78 hours is now available. This container, known as the Golden Hour container (GHC), will facilitate transport of RBCs. The GHC will have additional applications (transport and/or storage of vaccines, other biologics, organs, reagents, etc).


Assuntos
Preservação de Sangue/instrumentação , Eritrócitos , Meios de Transporte , Humanos , Temperatura
17.
J Mol Biol ; 334(1): 37-52, 2003 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-14596798

RESUMO

Double-stranded DNA packaging in bacteriophage T4 and other viruses occurs by translocation of DNA into an empty prohead by a packaging machine assembled at the portal vertex. Coordinated with this complex process is the cutting of concatemeric DNA to initiate and terminate DNA packaging and encapsidate one genome-length viral DNA. The catalytic site responsible for cutting, and the mechanisms by which cutting is precisely coordinated with DNA translocation remained as interesting open questions. Phage T4, unlike the phages with defined ends (e.g. lambda, T3, T7), packages DNA in a strictly headful manner, and exhibits no strict sequence specificity to initiate or terminate DNA packaging. Previous evidence suggests that the large terminase protein gp17, a key component of the T4 packaging machine, possesses a non-specific DNA cutting activity. A histidine-rich metal-binding motif, H382-X(2)-H385-X(16)-C402-X(8)-H411-X(2)-H414-X(15)-H430-X(5)-H436, in the C-terminal half of gp17 is thought to be involved in the terminase cleavage. Here, exhaustive site-directed mutagenesis revealed that none of the cysteine and histidine residues other than the H436 residue is critical for function. On the other hand, a cluster of conserved residues within this region, D401, E404, G405, and D409, are found to be critical for function. Biochemical analyses showed that the D401 mutants exhibited a novel phenotype, showing a loss of in vivo DNA cutting activity but not the DNA packaging activity. The functional nature of the critical residues and their disposition in the conserved loop region between two predicted beta-strands suggest that these residues are part of a metal-coordinated catalytic site that cleaves the phosphodiester bond of DNA substrate. The data suggest that the T4 terminase consists of at least two functional domains, an N-terminal DNA-translocating ATPase domain and a C-terminal DNA-cutting domain. Although the DNA recognition mechanisms may be distinct, it appears that T4 and other phage terminases employ a common catalytic paradigm for phosphodiester bond cleavage that is used by numerous nucleases.


Assuntos
Bacteriófago T4/metabolismo , DNA/metabolismo , Proteínas Virais/metabolismo , Adenosina Trifosfatases/metabolismo , Sequência de Aminoácidos , Ácido Aspártico/metabolismo , Bacteriófago T4/genética , Sítios de Ligação , Cisteína/metabolismo , DNA/química , Endodesoxirribonucleases/metabolismo , Histidina/metabolismo , Dados de Sequência Molecular , Mutação , Alinhamento de Sequência
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