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1.
J Pharm Pract ; : 8971900231213697, 2023 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-37941339

RESUMO

Purpose: Prior literature evaluating the importance of timely second-dose antibiotics in patients with sepsis has led to better outcomes and a possible reduction in mortality, length of mechanical ventilation, and length of time requiring vasopressors. Objective: To evaluate the impact of a newly developed pharmacist-led two-dose cefepime protocol implemented within an emergency department (ED) service. Methods: This was a retrospective, single-center, pre-post observational cohort study. Institutional review board approval was obtained. The primary endpoint was a reduction in time between the first and the second doses of antibiotics for patients with sepsis who present to the emergency department. Secondary endpoints included length of vasopressor therapy, intensive care unit (ICU) length of stay, hospital length of stay, duration of mechanical ventilation, and mortality. Results: A total of 84 patients were included in the pharmacist-led two-dose hospital protocol and 79 patients were included in the historical control. In the control cohort, the median time between the first and second dose of antibiotics was 12 hours vs 8.5 hours in the tested cohort. The average time requiring vasopressors was 1.20 days for the control cohort vs .46 days for the post-implementation group. Lastly, the median hospital length of stay in days was 8 for the control group vs 7 for the tested cohort. Conclusion: Implementation of a pharmacist-led two-dose cefepime protocol was associated with a numerically lower duration between second-dose antibiotics, days requiring vasopressors, and a slight reduction in hospital length of stay.

4.
Pediatr Emerg Care ; 37(5): 250-254, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-30045355

RESUMO

PURPOSE: This study aimed to compare analgesic efficacy of intranasal (IN) ketamine to IN fentanyl for moderate to severe pain in children in a pediatric emergency department. METHODS: A prospective, randomized, double-blinded, noninferiority study evaluating children aged 3 to 17 years in a pediatric emergency department with acute moderate to severe pain was conducted. Patients received either 1 mg/kg of IN ketamine or 1.5 µg/kg of IN fentanyl and were evaluated after 10, 20, 30, and 60 minutes. The primary outcome was the degree of pain reduction after 20 minutes. RESULTS: Twenty-two patients were enrolled (11 in each group). Underlying pain conditions represented were musculoskeletal injury (73%) and abdominal pain (27%). At 20 minutes after analgesia, there was no significant difference in pain scores between the fentanyl (median, 2; range, 0-8) and ketamine groups (median, 4; range, 0-7; P = 0.20). The ketamine group showed a significantly greater rate of adverse effects, 73% versus 9% (P = 0.002), and throughout the course of the study period, 7 patients in the ketamine group (64%) group showed some degree of sedation versus no one in the fentanyl group (P = 0.004). CONCLUSIONS: There was insufficient power to support the analgesic noninferiority of IN ketamine at a dose of 1 mg/kg compared with IN fentanyl at a dose of 1.5 µg/kg in children experiencing painful conditions at 20 minutes after administration. Intranasal ketamine was found to be inferior to IN fentanyl in relieving pain at 10 minutes and was found to have significantly greater rates of sedation and dizziness.


Assuntos
Ketamina , Administração Intranasal , Adolescente , Analgésicos/uso terapêutico , Criança , Pré-Escolar , Método Duplo-Cego , Fentanila/uso terapêutico , Humanos , Ketamina/uso terapêutico , Dor/tratamento farmacológico , Dor/etiologia , Medição da Dor , Estudos Prospectivos
5.
J Emerg Med ; 58(5): 725-732, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32247660

RESUMO

BACKGROUND: Ibuprofen (Motrin; Johnson & Johnson) and acetaminophen (APAP, paracetamol) are the most commonly used analgesics in the pediatric emergency department (ED) for managing a variety of acute traumatic and nontraumatic painful conditions. The multimodal pain management of using a combination of ibuprofen plus acetaminophen has the potential to result in greater analgesia. OBJECTIVE: We compared the analgesic efficacy of a combination of oral ibuprofen plus acetaminophen with either analgesic alone for pediatric ED patients with acute pain. METHODS: We performed a randomized, double-blind superiority trial assessing and comparing the analgesic efficacy of a combination of oral ibuprofen (10 mg/kg dose) plus acetaminophen (15 mg/kg per dose) to either analgesic alone for the treatment of acute traumatic and nontraumatic pain in the pediatric ED. Primary outcomes included a difference in pain scores among the three groups at 60 min. RESULTS: We enrolled 90 patients (30 per group). The difference in mean pain scores at 60 min between acetaminophen and combination groups was 0.30 (95% confidence interval [CI] -0.84 to 1.83); between ibuprofen and combination groups was -0.33 (95% CI -1.47 to 0.80); and between acetaminophen and ibuprofen groups was 0.63 (95% CI -0.54 to 1.81). Reductions in pain scores from baseline to 60 min were similar for all patients in each of the three groups. No adverse events occurred in any group. CONCLUSIONS: We found similar analgesic efficacy of oral ibuprofen and acetaminophen in comparison with each analgesic alone for short-term treatment of acute pain in the pediatric ED, but the trial was underpowered to demonstrate the analgesic superiority of the combination of oral ibuprofen plus acetaminophen in comparison with each analgesic alone.


Assuntos
Acetaminofen , Dor Aguda , Analgésicos não Narcóticos , Ibuprofeno , Acetaminofen/uso terapêutico , Dor Aguda/tratamento farmacológico , Analgésicos/uso terapêutico , Analgésicos não Narcóticos/uso terapêutico , Criança , Método Duplo-Cego , Serviço Hospitalar de Emergência , Humanos , Ibuprofeno/uso terapêutico , Medição da Dor
6.
Anesth Prog ; 67(1): 48-59, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32191501

RESUMO

For decades, the dental profession has provided the full spectrum of anesthesia services ranging from local anesthesia to general anesthesia in the office-based ambulatory environment to alleviate pain and anxiety. However, despite a reported record of safety, complications occasionally occur. Two common contributing factors to general anesthesia and sedation complications are medication errors and adverse drug events. The prevention and early detection of these complications should be of paramount importance to all dental providers who administer or otherwise use anesthesia services. Unfortunately, there is a lack of literature currently available regarding medication errors and adverse drug events involving anesthesia for dentistry. As a result, the profession is forced to look to the medical literature regarding these issues not only to assess the likely severity of the problem but also to develop preventive methods specific for general anesthesia and sedation as practiced within dentistry. Part 1 of this 2-part article illuminated the problems of medication errors and adverse drug events, primarily as documented within medicine. Part 2 will focus on how these complications affect dentistry, discuss several of the methods that medical anesthesia has implemented to manage such problems that may have utility in dentistry, and introduce a novel method for addressing these issues within dentistry known as the Dental Anesthesia Medication Safety Paradigm (DAMSP).


Assuntos
Anestesia Dentária , Anestesiologia , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Anestesia Dentária/efeitos adversos , Sedação Consciente , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/prevenção & controle , Humanos , Erros de Medicação/prevenção & controle
7.
Am J Emerg Med ; 38(2): 165-172, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-30770244

RESUMO

STUDY OBJECTIVE: To compare analgesic efficacy and safety of intravenous lidocaine and ketorolac combination to each analgesic alone for ED patients with suspected renal colic. METHODS: We conducted a randomized, double-blind trial comparing analgesic efficacy of a combination of intravenous lidocaine (1.5 mg/kg) and ketorolac (30 mg), to ketorolac (30 mg), and to lidocaine (1.5 mg/kg) in patients aged 18-64 presenting to the ED with suspected renal colic. Primary outcome included difference in pain scores between the groups at 30 min. Secondary outcomes included a comparative reduction in pain scores in each group from baseline to 30 and 60 min as well as rates of adverse events and need for rescue analgesia at 30 and 60 min. RESULTS: We enrolled 150 subjects (50 per group). The difference in mean pain scores at 30 min between Lidocaine and Lidocaine/Ketorolac groups was -2.89 (95% CI: -4.39 to -1.39); between Ketorolac and Lidocaine/Ketorolac group was -0.92 (95% CI: -2.44 to 0.61); and between Ketorolac and Lidocaine was -1.98 (95% CI: -3.69 to -0.27). A comparative percentage of subjects in each group required rescue analgesia at 30 and 60 min. No clinically concerning changes in vital signs were observed. No serious adverse events occurred in either group. Commonly reported adverse effects were dizziness, nausea, and headache. CONCLUSION: The administration of intravenous lidocaine/ketorolac combination to ED patients with suspected renal colic results in better analgesia in comparison to lidocaine alone but provides no analgesic advantages over ketorolac alone. Clinicaltrials.gov Registration: NCT02902770.


Assuntos
Combinação de Medicamentos , Cetorolaco/normas , Lidocaína/normas , Cólica Renal/tratamento farmacológico , Administração Intravenosa , Adulto , Analgésicos/normas , Analgésicos/uso terapêutico , Método Duplo-Cego , Serviço Hospitalar de Emergência/organização & administração , Serviço Hospitalar de Emergência/estatística & dados numéricos , Feminino , Humanos , Cetorolaco/uso terapêutico , Lidocaína/uso terapêutico , Masculino , Pessoa de Meia-Idade , Manejo da Dor/métodos , Manejo da Dor/normas , Cólica Renal/fisiopatologia
8.
Anesth Prog ; 66(3): 162-172, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31545675

RESUMO

For decades, the dental profession has provided anesthesia services in office-based, ambulatory settings to alleviate pain and anxiety, ranging from local anesthesia to general anesthesia. However, despite a reported record of safety, complications occasionally occur. Two common contributing factors to general anesthesia and sedation complications are medication errors and adverse drug events. The prevention and early detection of these complications should be of paramount importance to all dental providers who administer or otherwise use anesthesia services. Unfortunately, there is a substantial lack of literature currently available regarding medication errors and adverse drug events involving anesthesia for dentistry. As a result, the profession is forced to look to the medical literature regarding these issues not only to assess the likely severity of the problem but also to develop preventive methods specific for general anesthesia and sedation as practiced within dentistry. Part 1 of this 2-part article will illuminate the problems of medication errors and adverse drug events, primarily as documented within medicine. Part 2 will focus on how these complications affect dentistry, discuss several of the methods that medicine has implemented to manage such problems, and introduce a method for addressing these issues with the dental anesthesia medication safety paradigm.


Assuntos
Anestesia Dentária , Anestesiologia , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Erros de Medicação , Anestesia Dentária/efeitos adversos , Anestesia Geral , Odontologia , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/prevenção & controle , Humanos , Erros de Medicação/prevenção & controle
9.
Ann Emerg Med ; 74(4): 530-537, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31383385

RESUMO

STUDY OBJECTIVE: Nonsteroidal anti-inflammatory drugs (NSAIDs) are used extensively for the management of acute pain, with ibuprofen being one of the most frequently used oral analgesics in the emergency department (ED). We compare the analgesic efficacy of oral ibuprofen at 3 different doses for adult ED patients with acute pain. METHODS: This was a randomized, double-blind trial comparing analgesic efficacy of 3 doses of oral ibuprofen (400, 600, and 800 mg) in adult ED patients with acute painful conditions. Primary outcome included difference in pain scores between the 3 groups at 60 minutes. RESULTS: We enrolled 225 subjects (75 per group). The difference in mean pain scores at 60 minutes between the 400- and 600-mg groups was -0.14 (95% confidence interval [CI] -0.67 to 0.39); between the 400- and 800-mg groups, 0.14 (95% CI -0.65 to 0.37); and between the 600- and 800-mg groups, 0.00 (95% CI -0.47 to 0.47). Reductions in pain scores from baseline to 60 minutes were similar for all subjects in each of the 3 groups. No adverse events occurred in any group. CONCLUSION: Oral ibuprofen administered at doses of 400, 600, and 800 mg has similar analgesic efficacy for short-term pain relief in adult patients presenting to the ED with acute pain.


Assuntos
Dor Aguda/prevenção & controle , Analgésicos não Narcóticos/administração & dosagem , Ibuprofeno/administração & dosagem , Adulto , Relação Dose-Resposta a Droga , Método Duplo-Cego , Serviço Hospitalar de Emergência , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Medição da Dor , Resultado do Tratamento
10.
Am J Emerg Med ; 37(2): 220-227, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-29807629

RESUMO

STUDY OBJECTIVE: We compare the analgesic efficacy and safety of subdissociative intravenous-dose ketamine (SDK) versus morphine in geriatric Emergency Department (ED) patients. METHODS: This was a prospective, randomized, double-blind trial evaluating ED patients aged 65 and older experiencing moderate to severe acute abdominal, flank, musculoskeletal, or malignant pain. Patients were randomized to receive SDK at 0.3 mg/kg or morphine at 0.1 mg/kg by short intravenous infusion over 15 min. Evaluations occurred at 15, 30, 60, 90, and 120 min. Primary outcome was reduction in pain at 30 min. Secondary outcomes included overall rates of adverse effects and incidence of rescue analgesia. RESULTS: Thirty patients per group were enrolled in the study. The primary change in mean pain scores was not significantly different in the ketamine and morphine groups: 9.0 versus 8.4 at baseline (mean difference 0.6; 95% CI -0.30 to 1.43) and 4.2 versus 4.4 at 30 min (mean difference -0.2; 95% CI -1.93 to1.46). Patients in the SDK group reported higher rates of psychoperceptual adverse effects at 15, 30, and 60 min post drug administration. Two patients in the ketamine group and one in the morphine group experienced brief desaturation episodes. There were no statistically significant differences with respect to changes in vital signs and need for rescue medication. CONCLUSION: SDK administered at 0.3 mg/kg over 15 min provides analgesic efficacy comparable to morphine for short-term treatment of acute pain in the geriatric ED patients but results in higher rates of psychoperceptual adverse effects. ClinicalTrials.gov Registration #: NCT02673372.


Assuntos
Dor Aguda/tratamento farmacológico , Analgésicos Opioides/administração & dosagem , Anestésicos Dissociativos/administração & dosagem , Serviço Hospitalar de Emergência , Ketamina/administração & dosagem , Morfina/administração & dosagem , Idoso , Analgesia/métodos , Analgésicos Opioides/efeitos adversos , Anestésicos Dissociativos/efeitos adversos , Método Duplo-Cego , Feminino , Humanos , Infusões Intravenosas , Ketamina/efeitos adversos , Masculino , Morfina/efeitos adversos , Manejo da Dor/métodos , Medição da Dor , Estudos Prospectivos
11.
Oral Maxillofac Surg Clin North Am ; 30(2): 155-164, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29622309

RESUMO

Oral and maxillofacial surgeons have a variety of anesthetic agents that can be used to provide anesthesia safely and efficiently in the office-based environment. However, it is critical to have a thorough understanding of the particulars for each agent. Commonly used anesthetic agents, administered either individually or in combination, include diazepam, midazolam, propofol, ketamine, opioid agonists such as fentanyl or remifentanil, dexmedetomidine, and inhalational agents, including nitrous oxide and sevoflurane. These agents help provide extreme flexibility for those creating an individualized anesthetic plan that also balances the patient's history and the anticipated surgical plan to maximize success.


Assuntos
Anestesia Geral/métodos , Anestésicos Dissociativos/administração & dosagem , Anestésicos Dissociativos/farmacologia , Anestésicos Inalatórios/administração & dosagem , Anestésicos Inalatórios/farmacologia , Anestésicos Intravenosos/administração & dosagem , Anestésicos Intravenosos/farmacologia , Hipnóticos e Sedativos/farmacologia , Cirurgia Bucal , Dexmedetomidina , Diazepam , Humanos , Hipnóticos e Sedativos/administração & dosagem , Ketamina , Midazolam , Óxido Nitroso , Propofol
12.
Am J Emerg Med ; 35(8): 1095-1100, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28283340

RESUMO

STUDY OBJECTIVE: Compare adverse effects and analgesic efficacy of low-dose ketamine for acute pain in the ED administered either by single intravenous push (IVP) or short infusion (SI). METHODS: Patients 18-65, presenting to ED with acute abdominal, flank, or musculoskeletal pain with initial pain score≥5, were randomized to ketamine 0.3mg/kg by either IVP or SI with placebo double-dummy. Adverse effects were evaluated by Side Effects Rating Scale for Dissociative Anesthetics (SERSDA) and Richmond Agitation-Sedation Scale (RASS) at 5, 15, 30, 60, 90, and 120min post-administration; analgesic efficacy was evaluated by Numerical Rating Scale (NRS). RESULTS: 48 patients enrolled in the study. IVP group had higher overall rates of feeling of unreality on SERSDA scale: 92% versus 54% (difference 37.5%; p=0.008; 95% CI 9.3-59.5%). At 5min median severity of feeling of unreality was 3.0 for IVP versus 0.0 for SI (p=0.001). IVP also showed greater rates of sedation on RASS scale at 5min: median RASS -2.0 versus 0.0 (p=0.01). Decrease in mean pain scores from baseline to 15min was similar across groups: 5.2±3.53 (95% CI 3.7-6.7) for IVP; 5.75±3.48 (95% CI 4.3-7.2) for SI. There were no statistically significant differences with respect to changes in vital signs and need for rescue medication. CONCLUSION: Low-dose ketamine given as a short infusion is associated with significantly lower rates of feeling of unreality and sedation with no difference in analgesic efficacy in comparison to intravenous push.


Assuntos
Dor Aguda/tratamento farmacológico , Analgésicos/administração & dosagem , Analgésicos/uso terapêutico , Serviço Hospitalar de Emergência , Ketamina/administração & dosagem , Ketamina/uso terapêutico , Adulto , Relação Dose-Resposta a Droga , Método Duplo-Cego , Feminino , Humanos , Infusões Intravenosas , Masculino , Medição da Dor , Estudos Prospectivos , Resultado do Tratamento , Estados Unidos
13.
EMBO J ; 33(22): 2721-34, 2014 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-25319415

RESUMO

Natural killer (NK) cells are an innate lymphoid cell lineage characterized by their capacity to provide rapid effector functions, including cytokine production and cytotoxicity. Here, we identify the Ikaros family member, Aiolos, as a regulator of NK-cell maturation. Aiolos expression is initiated at the point of lineage commitment and maintained throughout NK-cell ontogeny. Analysis of cell surface markers representative of distinct stages of peripheral NK-cell maturation revealed that Aiolos was required for the maturation in the spleen of CD11b(high)CD27(-) NK cells. The differentiation block was intrinsic to the NK-cell lineage and resembled that found in mice lacking either T-bet or Blimp1; however, genetic analysis revealed that Aiolos acted independently of all other known regulators of NK-cell differentiation. NK cells lacking Aiolos were strongly hyper-reactive to a variety of NK-cell-mediated tumor models, yet impaired in controlling viral infection, suggesting a regulatory function for CD27(-) NK cells in balancing these two arms of the immune response. These data place Aiolos in the emerging gene regulatory network controlling NK-cell maturation and function.


Assuntos
Diferenciação Celular/imunologia , Imunidade Celular , Células Matadoras Naturais/imunologia , Transativadores/imunologia , Animais , Antígeno CD11b/genética , Antígeno CD11b/imunologia , Diferenciação Celular/genética , Redes Reguladoras de Genes/imunologia , Fator de Transcrição Ikaros , Células Matadoras Naturais/citologia , Camundongos , Camundongos Knockout , Neoplasias Experimentais/genética , Neoplasias Experimentais/imunologia , Fator 1 de Ligação ao Domínio I Regulador Positivo , Proteínas com Domínio T/genética , Proteínas com Domínio T/imunologia , Transativadores/genética , Fatores de Transcrição/genética , Fatores de Transcrição/imunologia , Membro 7 da Superfamília de Receptores de Fatores de Necrose Tumoral/genética , Membro 7 da Superfamília de Receptores de Fatores de Necrose Tumoral/imunologia , Viroses/genética , Viroses/imunologia
14.
J Immunol ; 185(11): 6679-88, 2010 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-20974986

RESUMO

Although NK cells are well known for their cytotoxic functions, they also produce an array of immunoregulatory cytokines and chemokines. During an immune response, NK cells are exposed to complex combinations of cytokines that influence their differentiation and function. In this study, we have examined the phenotypic and functional consequences of exposing mouse NK cells to IL-4, IL-12, IL-15, IL-18, and IL-21 and found that although all factors induced signs of maturation, characterized by decreased proliferation and IFN-γ secretion, distinct combinations induced unique cytokine secretion profiles. In contrast, the immunosuppressive factors IL-10 and TGF-ß had little direct effect on NK cell effector functions. Sustained IL-18 signals resulted in IL-13 and GM-CSF production, whereas IL-12 and IL-21 induced IL-10 and TNF-α. Surprisingly, with the exception of IL-21, all cytokines suppressed cytotoxic function of NK cells at the expense of endogenous cytokine production suggesting that "helper-type" NK cells were generated. The cytokine signals also profoundly altered the cell surface phenotype of the NK cells-a striking example being the downregulation of the activating receptor NKG2D by IL-4 that resulted in decreased NKG2D-dependent killing. IL-4 exposure also modulated NKG2D expression in vivo suggesting it is functionally important during immune responses. This study highlights the plasticity of NK cell differentiation and suggests that the relative abundance of cytokines at sites of inflammation will lead to diverse outcomes in terms of NK cell phenotype and interaction with the immune system.


Assuntos
Diferenciação Celular/imunologia , Citocinas/metabolismo , Mediadores da Inflamação/metabolismo , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/metabolismo , Animais , Diferenciação Celular/genética , Células Cultivadas , Citocinas/antagonistas & inibidores , Citocinas/fisiologia , Testes Imunológicos de Citotoxicidade , Proteínas de Homeodomínio/genética , Humanos , Imunofenotipagem , Mediadores da Inflamação/fisiologia , Células Matadoras Naturais/citologia , Proteínas de Membrana/metabolismo , Proteínas de Membrana/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Transdução de Sinais/genética , Transdução de Sinais/imunologia
15.
J Exp Med ; 204(11): 2579-90, 2007 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-17923506

RESUMO

Interferon-producing killer dendritic cells (IKDCs) have been described as possessing the lytic potential of NK cells and the antigen-presenting capacity of dendritic cells (DCs). In this study, we examine the lytic function and antigen-presenting capacity of mouse spleen IKDCs, including those found in DC preparations. IKDCs efficiently killed NK cell targets, without requiring additional activation stimuli. However, in our hands, when exposed to protein antigen or to MHC class II peptide, IKDCs induced little or no T cell proliferation relative to conventional DCs or plasmacytoid DCs, either before or after activation with CpG, or in several disease models. Certain developmental features indicated that IKDCs resembled NK cells more than DCs. IKDCs, like NK cells, did not express the transcription factor PU.1 and were absent from recombinase activating gene-2-null, common gamma-chain-null (Rag2(-/-)Il2rg(-/-)) mice. When cultured with IL-15 and -18, IKDCs proliferated extensively, like NK cells. Under these conditions, a proportion of expanded IKDCs and NK cells expressed high levels of surface MHC class II. However, even such MHC class II(+) IKDCs and NK cells induced poor T cell proliferative responses compared with DCs. Thus, IKDCs resemble NK cells functionally, and neither cell type could be induced to be effective antigen-presenting cells.


Assuntos
Células Dendríticas/imunologia , Interferons/biossíntese , Células Matadoras Naturais/imunologia , Animais , Células Dendríticas/classificação , Antígenos de Histocompatibilidade Classe II/imunologia , Imunofenotipagem , Integrina alfa2/análise , Integrina alfa2/imunologia , Interferons/imunologia , Células Matadoras Naturais/classificação , Antígenos Comuns de Leucócito/análise , Antígenos Comuns de Leucócito/imunologia , Ativação Linfocitária , Camundongos , Baço/imunologia , Linfócitos T/imunologia
16.
J Immunol ; 178(8): 4764-70, 2007 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-17404256

RESUMO

NK cells are important for the clearance of tumors, parasites, and virus-infected cells. Thus, factors that control NK cell numbers and function are critical for the innate immune response. A subset of NK cells express the inhibitory killer cell lectin-like receptor G1 (KLRG1). In this study, we identify that KLRG1 expression is acquired during periods of NK cell division such as development and homeostatic proliferation. KLRG1(+) NK cells are mature in phenotype, and we show for the first time that these cells have a slower in vivo turnover rate, reduced proliferative response to IL-15, and poorer homeostatic expansion potential compared with mature NK cells lacking KLRG1. Transfer into lymphopenic recipients indicate that KLRG1(-) NK cells are precursors of KLRG1(+) NK cells and KLRG1 expression accumulates following cell division. Furthermore, KLRG1(+) NK cells represent a significantly greater proportion of NK cells in mice with enhanced NK cell numbers such as Cd45(-/-) mice. These data indicate that NK cells acquire KLRG1 on their surface during development, and this expression correlates with functional distinctions from other peripheral NK cells in vivo.


Assuntos
Células Matadoras Naturais/fisiologia , Receptores Imunológicos/biossíntese , Animais , Homeostase , Interleucina-12/farmacologia , Interleucina-18/farmacologia , Células Matadoras Naturais/imunologia , Lectinas Tipo C , Antígenos Comuns de Leucócito/análise , Ativação Linfocitária , Antígeno de Macrófago 1/análise , Camundongos , Camundongos Endogâmicos C57BL , Receptores Imunológicos/análise , Membro 7 da Superfamília de Receptores de Fatores de Necrose Tumoral/análise , Regulação para Cima
17.
Eur J Immunol ; 36(12): 3294-304, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17111353

RESUMO

Unlike early B/T cell development, NK cell lineage commitment is not well understood, with a major limitation being the lack of a robust culture system to assay NK cell progenitors. Here we have exploited the multi-lineage potential of Pax5(-/-) pro-B cells to establish an effective system to direct differentiation of progenitors into the NK cell lineage. Cultivation of Pax5(-/-) pro-B cells on OP9 cells expressing the Notch ligand Delta-Like1 (OP9-DL1) in the presence of IL-7 efficiently induced T and NK cell potential. For NK cells, Notch was only transiently required, as prolonged signaling decreased NK and increased T cell development. Pure NK cell populations could be obtained by the culture of these Notch signal-experienced cells onto OP9 stroma and IL-15. A similar transient exposure to Notch was also compatible with the differentiation of NK cells from hematopoietic progenitors, while sustained Notch signaling impaired NK cell generation. Pax5(-/-) pro-B cell-derived NK cells were cytotoxic, secreted cytokines and expressed all the expected NK cell-specific surface markers examined except the Ly49 family, a phenotype similar to fetal NK cells. These data indicate that Notch signaling induces T/NK cell differentiation in Pax5(-/-) pro-B cells that is strikingly similar to early thymopoiesis.


Assuntos
Linfócitos B/citologia , Células Matadoras Naturais/citologia , Fator de Transcrição PAX5/deficiência , Receptores Notch/fisiologia , Transdução de Sinais/imunologia , Células-Tronco/citologia , Animais , Linfócitos B/imunologia , Linfócitos B/metabolismo , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Linhagem Celular , Linhagem Celular Tumoral , Linhagem da Célula/imunologia , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fator de Transcrição PAX5/genética , Transdução de Sinais/genética , Células-Tronco/imunologia , Células-Tronco/metabolismo
18.
Xenotransplantation ; 13(6): 536-46, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17059581

RESUMO

BACKGROUND: Natural killer (NK) cells have emerged as major players in anti-viral and anti-tumour immune responses. Like cytotoxic T lymphocytes (CTL), they express perforin and are potent secretors of gamma-interferon (IFN-gamma). However, there is conflicting evidence about their role in mediating rejection of xenogeneic tissue. METHODS: A pig-to-mouse peritoneal cell model of xenotransplantation was used to investigate the effect of NK deficiency on xenograft recovery and the possible mechanisms behind this NK-mediated graft rejection. gamma c(-/-)RAG(-/-) mice were used as a model of NK deficiency. Additionally, NK cells were depleted in RAG(-/-) mice using anti-asialo GM1. The contributions of IFN-gamma, perforin and NKT cells were studied using knock-out mice that were depleted in vivo of T cells. Mice were injected with 10(7) pig cells intraperitoneally and peritoneal fluid was assessed 5 days later for xenograft recovery and phenotypic analysis. The requirement for NK cells for xenograft rejection was also assessed using luciferase-transfected porcine cells in a renal subcapsular model of transplantation. RESULTS: Pig cell recovery was enhanced in both gamma c(-/-)RAG(-/-) and NK-depleted RAG(-/-) mice when compared with RAG(-/-) control mice. IFN-gamma(-/-) mice depleted of T cells also demonstrated superior graft survival compared with their B6 counterparts. However, there were minimal graft survival differences between Pfp(-/-) and B6 control mice. Similarly, a deficiency in NKT cells did not improve pig xenograft recovery from the peritoneum of these mice. CONCLUSIONS: Therefore, we conclude that NK cells, but not NKT cells, are important mediators of xenograft rejection in the peritoneal cavity, and that their role may be unmasked in the absence of T cells. The mechanism for this xenorejection appears to involve IFN-gamma but is perforin independent.


Assuntos
Rejeição de Enxerto/imunologia , Interferon gama/imunologia , Células Matadoras Naturais/imunologia , Animais , Linhagem Celular , Interferon gama/deficiência , Interferon gama/genética , Interferon gama/metabolismo , Células Matadoras Naturais/metabolismo , Glicoproteínas de Membrana/deficiência , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Camundongos , Camundongos Knockout , Perforina , Peritônio/imunologia , Peritônio/metabolismo , Proteínas Citotóxicas Formadoras de Poros/deficiência , Proteínas Citotóxicas Formadoras de Poros/genética , Proteínas Citotóxicas Formadoras de Poros/metabolismo , Suínos , Transplante Heterólogo/imunologia
19.
Crit Rev Immunol ; 24(4): 239-50, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15588224

RESUMO

The common gamma chain family of cytokine receptors plays a plethora of roles during the early development, activation, and terminal differentiation of the lymphocyte lineages. The most recently identified member of this family, the IL-21R, is expressed to varying degrees on B, T lymphocytes, and natural killer (NK) cells, whereas IL-21, is reportedly only produced by activated CD4+ T cells. In keeping with this expression pattern the IL-21:IL-21R interaction is important for the latter stages and function of all three lymphoid lineages. IL-21 is a regulator of A-cell differentiation to plasma cells as well as immunoglobulin class switching. In contrast, within the T-cell lineage, IL-21 acts as a co-stimulator of proliferation, enhances memory response, and modulates homeostasis. Within the innate immune system IL-21 has a role in the terminal differentiation of NK cells, enhancing cytotoxic function while also decreasing cellular viability. These immune maturation and stimulating functions have resulted in IL-21 being tested in a variety of models of immunity. In these contexts, IL-21 has shown very promising efficacy in a number of antitumor immune responses mediated by NK and or T lymphocytes.


Assuntos
Diferenciação Celular/imunologia , Interleucinas/imunologia , Linfócitos/imunologia , Animais , Linfócitos B/citologia , Linfócitos B/imunologia , Humanos , Subunidade alfa de Receptor de Interleucina-21 , Interleucinas/genética , Células Matadoras Naturais/citologia , Células Matadoras Naturais/imunologia , Linfócitos/citologia , Camundongos , Modelos Imunológicos , Plasmócitos/citologia , Plasmócitos/imunologia , Receptores de Interleucina/genética , Receptores de Interleucina/imunologia , Receptores de Interleucina-21 , Linfócitos T/citologia , Linfócitos T/imunologia
20.
J Immunol ; 172(4): 2048-58, 2004 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-14764669

RESUMO

IL-21 is a recently identified cytokine that stimulates mouse NK cell effector functions in vitro. In this study we demonstrate that IL-21 achieves its stimulatory effect by inducing the development of mature NK cells into a large granular lymphocyte phenotype with heightened effector function. IL-21 treatment results in increased cell size and granularity and a corresponding decrease in cell viability and proliferative potential. These cells up-regulate the expression of the inhibitory CD94-NKG2A receptor complex and the activation markers CD154 and killer cell, lectin-like-receptor G1. Surprisingly, IL-21 treatment also results in down-regulation of the pan-NK marker, NK1.1. Coinciding with these cellular changes IL-21 enhances cytolytic capacity across a spectrum of target sensitivities and induces IL-10 and IFN-gamma production. In vivo treatment with IL-21 results in a very similar activation and phenotypic maturation of NK cells as well as a potent increase in NK cell-mediated anti-tumor immunity that is perforin dependent. These developmental changes suggested that IL-21 functions to induce the terminal differentiation of mouse NK cells, resulting in heightened NK cell-mediated cytotoxicity and immune surveillance.


Assuntos
Interleucinas/fisiologia , Células Matadoras Naturais/citologia , Células Matadoras Naturais/imunologia , Animais , Antígenos/biossíntese , Antígenos Ly , Antígenos de Superfície , Biomarcadores/análise , Diferenciação Celular/imunologia , Linhagem Celular Tumoral , Membrana Celular/imunologia , Membrana Celular/metabolismo , Células Cultivadas , Citocinas/biossíntese , Citocinas/metabolismo , Citotoxicidade Imunológica/imunologia , Regulação para Baixo/imunologia , Inibidores do Crescimento/administração & dosagem , Inibidores do Crescimento/fisiologia , Imunofenotipagem , Interleucina-15/fisiologia , Interleucina-2/fisiologia , Interleucinas/administração & dosagem , Células Matadoras Naturais/metabolismo , Lectinas Tipo C , Neoplasias Hepáticas/imunologia , Neoplasias Hepáticas/prevenção & controle , Neoplasias Hepáticas/secundário , Ativação Linfocitária/imunologia , Subpopulações de Linfócitos/imunologia , Subpopulações de Linfócitos/metabolismo , Melanoma Experimental/imunologia , Melanoma Experimental/prevenção & controle , Melanoma Experimental/secundário , Glicoproteínas de Membrana/deficiência , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/fisiologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Subfamília B de Receptores Semelhantes a Lectina de Células NK , Perforina , Proteínas Citotóxicas Formadoras de Poros , Biossíntese de Proteínas , Proteínas/antagonistas & inibidores
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