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1.
Tech Coloproctol ; 24(4): 283-290, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32036461

RESUMO

BACKGROUND: Colorectal anastomotic complications are dreaded and dramatically affect outcomes. Causes are multifactorial, with the size of the end-to-end anastomosis (EEA) stapler a modifiable factor and potential target for risk reduction. Our goal was to examine the impact of the EEA stapler size on the risk of anastomotic complications in left-sided colorectal resections. METHODS: A prospective divisional database was reviewed for consecutive elective left-sided resections with a colorectal anastomosis using an EEA stapler from January 2013 May 2018 inclusive. Patients were stratified into 25-29 mm or 30-33 mm cohorts. Patient and disease demographics, operative variables, and postoperative outcomes were evaluated. The main outcome measures were the rate and factors associated with anastomotic complications. RESULTS: Four hundred seventy-three cases were evaluated, 185 ( 39.1%) were in the 25-29 mm group and 288 (60.9%) in the 30-33 mm group. Patients were comparable in demographics and operative variables. More males were anastomosed with the 30-33 mm than with the 25-29 mm stapler (57.6% vs 28.6%, p < 0.01). Significantly more patients developed an anastomotic stricture with the 25-29 mm than with the 30-33 mm staplers (7.1% vs. 2.1%; p = 0.007). There was no significant difference in leak rates or reoperation/interventions between groups. On logistic regression, neither gender, operative indication nor approach were associated with anastomotic leak, readmission, or reoperation/intervention. Stapler size remained significantly associated with stricture (p = 0.032). CONCLUSIONS: The 25-29 mm EEA staplers were associated with an increased rate of anastomotic stricture compared to 30-33 mm staplers in left-sided colorectal anastomoses. As stapler size is a simple process measure that is easily modifyable, this is a potential target for improving anastomotic complication rates. Further controlled trials may help assess the impact of stapler size on improving patient and quality outcomes.


Assuntos
Neoplasias Colorretais , Reto , Anastomose Cirúrgica/efeitos adversos , Fístula Anastomótica/epidemiologia , Fístula Anastomótica/etiologia , Humanos , Masculino , Estudos Prospectivos , Reto/cirurgia , Grampeadores Cirúrgicos
2.
Ir J Med Sci ; 174(4): 10-6, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16445154

RESUMO

BACKGROUND: Colorectal cancer (CRC) has the second highest mortality rate of all cancers in Ireland. Developments in imaging, surgical technique, and perioperative care in the last two decades have altered management. AIMS: To determine whether outcome following surgery for CRC in the mid-west has changed over a 22-year period. METHODS: Four hundred and twenty-two patients were divided into two time periods: Group A (1980-1991, n = 203) and Group B (1992-2002, n = 219) and demographic, inpatient, and survival data were reviewed. RESULTS: The mean age was 67 years, 59% were male. Group B patients had less advanced disease at presentation (Dukes' stage D 14% vs 22%, p < 0.05), fewer perioperative complications (13% vs 23%, p < 0.05), and fewer local recurrences (6.8% vs 11.8%, p < 0.05) than Group A. No difference in 30-day mortality rate or survival was detected. CONCLUSIONS: Although perioperative CRC management has improved, methods of earlier diagnosis and improvements in adjuvant therapy should be explored to improve survival.


Assuntos
Causas de Morte , Colectomia/métodos , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/cirurgia , Complicações Pós-Operatórias/mortalidade , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Anastomose Cirúrgica/efeitos adversos , Anastomose Cirúrgica/métodos , Biópsia por Agulha , Estudos de Coortes , Colectomia/efeitos adversos , Colonoscopia/métodos , Neoplasias Colorretais/patologia , Feminino , Humanos , Imuno-Histoquímica , Incidência , Irlanda/epidemiologia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Estudos Retrospectivos , Medição de Risco , Distribuição por Sexo , Análise de Sobrevida
3.
J Biol Chem ; 276(51): 48549-53, 2001 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-11602579

RESUMO

E-selectin is a cytokine-inducible adhesion molecule that is expressed by activated endothelial cells at sites of inflammation. In addition to supporting rolling and stable arrest of leukocytes, there is increasing evidence that E-selectin functions in transmembrane signaling into endothelial cells during these adhesive interactions. We have previously shown that adhesion of HL-60 cells (which express ligands for E-selectin), or antibody-mediated cross-linking of E-selectin, results in formation of a Ras/Raf-1/phospho-MEK macrocomplex, extracellular signal-regulated protein kinase (ERK1/2) activation, and c-fos up-regulation. All of these downstream signaling events appear to require an intact cytoplasmic domain of E-selectin. Here we demonstrate that tyrosine 603 in the cytoplasmic domain of E-selectin is required for the E-selectin-dependent ERK1/2 activation. Tyrosine 603 plays an important role in mediating the association of E-selectin with SHP2, and the catalytic domain of SHP2 is, in turn, critical for E-selectin-dependent ERK1/2 activation. An adapter protein complex consisting of Shc.Grb2.Sos bridges between SHP2 and the Ras.Raf.phospho-MEK macrocomplex. These molecular events thus outline a mechanism by which cross-linking of E-selectin by engagement of ligands on adherent leukocytes can initiate a multifunctional signaling pathway in the activated endothelial cell at sites of inflammation.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Selectina E/metabolismo , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Proteínas Tirosina Fosfatases/metabolismo , Transdução de Sinais , Animais , Sequência de Bases , Células COS , Domínio Catalítico , Primers do DNA , Selectina E/química , Ativação Enzimática , Proteína Adaptadora GRB2 , Peptídeos e Proteínas de Sinalização Intracelular , Proteína Quinase 3 Ativada por Mitógeno , Proteína Oncogênica p21(ras)/metabolismo , Fosforilação , Ligação Proteica , Proteína Tirosina Fosfatase não Receptora Tipo 11 , Proteína Tirosina Fosfatase não Receptora Tipo 6 , Proteínas Tirosina Fosfatases/química , Proteínas/metabolismo , Proteína Son Of Sevenless de Drosófila/metabolismo , Tirosina/metabolismo
4.
Ir J Med Sci ; 170(2): 98-9, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11491060

RESUMO

BACKGROUND: Laparoscopic cholecystectomy is the operation of choice for cholelithiasis. AIMS: The aims of our study were to assess the feasibility of day case laparoscopic cholecystectomy (DCLC) in selected patients. METHODS: DCLC was introduced in this unit in July 1999. The first 50 patients were prospectively evaluated up to February 2001. RESULTS: All patients were under 55 years of age with an ASA grade of I (n = 48) or II (n = 2). The mean age was 41.1 years (range 20-55 years) and the male:female ratio was 1:6. All patients had a standard anaesthetic protocol. Patients were discharged 10 to 12 hours postoperatively with a pro forma, which was reviewed at one week in the clinic. The conversion rate was 2%. Three required overnight admission due to excessive nausea, hypertension and for an unforeseen psychosocial problem. Ninety per cent of patients were suitable for same day discharge. No patient required subsequent readmission. CONCLUSION: DCLC is feasible and safe in carefully selected patients and has the advantages of convenience and cost-effectiveness.


Assuntos
Procedimentos Cirúrgicos Ambulatórios , Colecistectomia Laparoscópica , Adolescente , Adulto , Procedimentos Cirúrgicos Ambulatórios/métodos , Procedimentos Cirúrgicos Ambulatórios/estatística & dados numéricos , Colecistectomia Laparoscópica/métodos , Colecistectomia Laparoscópica/estatística & dados numéricos , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Estudos Prospectivos
5.
J Exp Med ; 192(5): 695-704, 2000 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-10974035

RESUMO

Transforming growth factor (TGF)-beta(1) is a pleiotropic cytokine/growth factor that is thought to play a critical role in the modulation of inflammatory events. We demonstrate that exogenous TGF-beta(1) can inhibit the expression of the proinflammatory adhesion molecule, E-selectin, in vascular endothelium exposed to inflammatory stimuli both in vitro and in vivo. This inhibitory effect occurs at the level of transcription of the E-selectin gene and is dependent on the action of Smad proteins, a class of intracellular signaling proteins involved in mediating the cellular effects of TGF-beta(1). Furthermore, we demonstrate that these Smad-mediated effects in endothelial cells result from a novel competitive interaction between Smad proteins activated by TGF-beta(1) and nuclear factor kappaB (NFkappaB) proteins activated by inflammatory stimuli (such as cytokines or bacterial lipopolysaccharide) that is mediated by the transcriptional coactivator cyclic AMP response element-binding protein (CREB)-binding protein (CBP). Augmentation of the limited amount of CBP present in endothelial cells (via overexpression) or selective disruption of Smad-CBP interactions (via a dominant negative strategy) effectively antagonizes the ability of TGF-beta(1) to block proinflammatory E-selectin expression. These data thus demonstrate a novel mechanism of interaction between TGF-beta(1)-regulated Smad proteins and NFkappaB proteins regulated by inflammatory stimuli in vascular endothelial cells. This type of signaling mechanism may play an important role in the immunomodulatory actions of this cytokine/growth factor in the cardiovascular system.


Assuntos
Proteínas de Ligação a DNA/fisiologia , Selectina E/genética , Endotélio Vascular/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , NF-kappa B/fisiologia , Transativadores/fisiologia , Fator de Crescimento Transformador beta/farmacologia , Animais , Células Cultivadas , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/fisiologia , Endotélio Vascular/citologia , Humanos , Interleucina-1/farmacologia , Ratos , Proteína Smad2 , Proteína Smad3
6.
J Immunol ; 165(4): 2142-8, 2000 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-10925300

RESUMO

E-selectin, a cytokine-inducible adhesion molecule, supports rolling and stable arrest of leukocytes on activated vascular endothelium. Previous studies have suggested that this transmembrane protein can also transduce signals into the endothelial cell. We now demonstrate activation of the mitogen-activated protein kinase (MAPK) signaling cascade in cultured HUVEC in response to E-selectin-dependent leukocyte adhesion and Ab-mediated cross-linking of cell surface E-selectin. Adhesion of increasing numbers of HL60 cells to IL-1beta-activated HUVEC stimulated robust increases in MAPK activity that were abrogated by an E-selectin blocking Ab. Cross-linking of cell surface E-selectin with Abs, as a mimic of multivalent ligand engagement, strongly stimulated MAPK/extracellular signal-related kinase (ERK) kinase (MEK)-dependent MAPK activation and concomitant up-regulation of mRNA for c-fos, an immediate early response gene, whereas Ab cross-linking of HLA class I molecules (present at comparable density) failed to do so. Coimmunoprecipitation documented Ras, Raf-1 and, phospho-MEK complex formation. Unactivated HUVEC transduced with a full-length adenoviral E-selectin construct also exhibited cross-link-induced MAPK activation, macromolecular complex formation, and c-fos up-regulation, whereas HUVEC transduced with a cytoplasmic domain deletion mutant failed to respond. These observations indicate that E-selectin can transduce an activating stimulus via the MAPK cascade into the endothelial cell during leukocyte adhesion.


Assuntos
Selectina E/fisiologia , Endotélio Vascular/enzimologia , Endotélio Vascular/imunologia , Proteínas Quinases Ativadas por Mitógeno/fisiologia , Transdução de Sinais/imunologia , Anticorpos Monoclonais/fisiologia , Adesão Celular/imunologia , Membrana Celular/imunologia , Membrana Celular/metabolismo , Células Cultivadas , Citocinas/fisiologia , Citoplasma/enzimologia , Citoplasma/metabolismo , Selectina E/imunologia , Selectina E/metabolismo , Endotélio Vascular/citologia , Endotélio Vascular/metabolismo , Ativação Enzimática/imunologia , Humanos , Leucócitos/imunologia , Substâncias Macromoleculares , Quinases de Proteína Quinase Ativadas por Mitógeno/fisiologia , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Fosfoproteínas/metabolismo , Estrutura Terciária de Proteína , Proteínas Proto-Oncogênicas c-fos/biossíntese , Proteínas Proto-Oncogênicas c-fos/genética , Proteínas Proto-Oncogênicas c-raf/metabolismo , RNA Mensageiro/biossíntese , Veias Umbilicais , Regulação para Cima/imunologia , Proteínas ras/metabolismo
7.
Mayo Clin Proc ; 75(3): 311-3, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10725962

RESUMO

There are many opportunities for short-term medical service internationally. Prerequisite preparation must include consideration of motivation, flexibility, culturally sensitive health care, and problems in communication and patient approach. Practical considerations require recognizing the importance of choice of locale, lack of materials and equipment, health concerns, travel, and expenses. A reference for opportunities available and a list of articles suggested as supplementary reading are provided.


Assuntos
Atenção à Saúde , Cooperação Internacional , Médicos , Comunicação , Características Culturais , Países em Desenvolvimento , Saúde Holística , Humanos , Motivação , Recursos Humanos
8.
Neurology ; 54(2): 494-6, 2000 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-10668722

RESUMO

We report an isolated musculocutaneous neuropathy caused by a proximal humeral osteochondroma that became symptomatic after the patient played recreational basketball. Lesion resection resulted in complete deficit resolution. Mass lesions involving the musculocutaneous nerve should be considered in patients with atraumatic, isolated musculocutaneous neuropathies that are recurrent or fail to recover, even in the setting of strenuous exercise.


Assuntos
Neoplasias Ósseas/complicações , Úmero , Nervo Musculocutâneo/fisiopatologia , Osteocondroma/complicações , Doenças do Sistema Nervoso Periférico/etiologia , Adulto , Neoplasias Ósseas/diagnóstico , Neoplasias Ósseas/cirurgia , Plexo Braquial/fisiopatologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Osteocondroma/diagnóstico , Osteocondroma/cirurgia , Esforço Físico
10.
J Immunol ; 161(2): 933-41, 1998 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-9670972

RESUMO

E-selectin, a selectin expressed on activated vascular endothelium, supports rolling and stable adhesion of leukocytes at sites of inflammation. Previously, we have reported that leukocyte adhesion to cultured endothelial cells induces association of the cytoplasmic domain of E-selectin with cytoskeletal elements, suggesting that outside-in signaling may occur during E-selectin-mediated adhesion. To investigate this potential signaling function of E-selectin, HUVEC activated with recombinant human IL-1beta (10 U/ml, 4 h) were labeled with [32P]orthophosphate, and E-selectin was immunoprecipitated using mAb H18/7. Autoradiography revealed constitutive phosphorylation of E-selectin in these cells and time-dependent dephosphorylation following adhesion of HL-60 cells. Cross-linking of cell surface E-selectin using H18/7 and a polyclonal secondary Ab induced E-selectin dephosphorylation, as did adhesion of beads coated with recombinant P-selectin glycoprotein ligand-1 (PSGL-1), an E-selectin ligand. Using adenoviral vector-mediated transfection in HUVEC of a tail-less E-selectin and phosphoamino acid analysis, we documented phosphorylation occurring exclusively within the cytoplasmic domain and involving serine residues. Additional experiments using a series of cytoplasmic domain mutants of E-selectin expressed in COS-7 cells localized the regions that were constitutively phosphorylated. Preincubation with okadaic acid and sodium vanadate abrogated adhesion-induced dephosphorylation of E-selectin. Thus, E-selectin, which is constitutively phosphorylated in cytokine-activated human endothelial cells, undergoes an enzymatically regulated dephosphorylation following leukocyte adhesion. This process appears to be triggered by multivalent ligand binding and/or cross-linking of cell surface E-selectin. Ligand-dependent regulation of the phosphorylation of E-selectin's cytoplasmic domain provides additional evidence for a transmembrane signaling function of this molecule during leukocyte-endothelial interactions.


Assuntos
Citoplasma/metabolismo , Selectina E/metabolismo , Endotélio Vascular/metabolismo , Leucócitos/metabolismo , Sequência de Aminoácidos , Anticorpos Monoclonais/metabolismo , Adesão Celular/imunologia , Linhagem Celular , Membrana Celular/imunologia , Membrana Celular/metabolismo , Reagentes de Ligações Cruzadas , Citoplasma/imunologia , Selectina E/genética , Selectina E/imunologia , Endotélio Vascular/enzimologia , Endotélio Vascular/imunologia , Vetores Genéticos/metabolismo , Células HL-60 , Humanos , Leucócitos/imunologia , Ligantes , Glicoproteínas de Membrana/metabolismo , Microesferas , Dados de Sequência Molecular , Selectina-P/metabolismo , Fosforilação , Fosfosserina/metabolismo , Estrutura Terciária de Proteína , Proteínas Tirosina Fosfatases/antagonistas & inibidores , Veias Umbilicais
11.
Arterioscler Thromb Vasc Biol ; 15(8): 1211-8, 1995 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-7542999

RESUMO

An immunoconjugate was designed to target hirudin, a potent and specific inhibitor of thrombin, to the surface of activated endothelial cells. Hirudin was covalently cross-linked to the monoclonal antibody H18/7 that recognizes the extracellular domain of E-selectin (CD62E), an endothelium-leukocyte adhesion molecule that is expressed only on cytokine-activated endothelium. The hirudin-H18/7 immunoconjugate selectively bound to interleukin-1-activated but not to unactivated cultured human umbilical vein endothelial cells with a temporal profile similar to that of inducible cell-surface procoagulant activity. When bound to activated endothelial cells, the hirudin-H18/7 immunoconjugate significantly inhibited endogenous thrombin activity generated from coincubated human plasma and fibrin clot formation on the monolayer surface. Cellular responses that are mediated via the thrombin receptor, such as increases in cytoskeletal F-actin content, also were significantly downregulated, and monolayers were protected from thrombin-induced disruption by this treatment. The ability to selectively antagonize thrombin-dependent processes at the endothelium-blood interface may provide new insights into complex pathophysiological processes, such as thrombosis, inflammation, and atherogenesis. These studies also demonstrate the general feasibility of selective targeting of therapeutic agents to endothelial cells based on recognition of an activation-dependent surface phenotype.


Assuntos
Endotélio Vascular/efeitos dos fármacos , Hirudinas/administração & dosagem , Trombina/antagonistas & inibidores , Actinas/metabolismo , Coagulação Sanguínea/efeitos dos fármacos , Moléculas de Adesão Celular/imunologia , Células Cultivadas , Selectina E , Endotélio Vascular/imunologia , Humanos , Imunoconjugados , Técnicas In Vitro
12.
Microcirculation ; 2(2): 151-63, 1995 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-7497167

RESUMO

OBJECTIVE: Establish a reproducible method for the isolation and cultivation of murine pulmonary microvascular endothelium. To this end, we exploited the localized pattern of microvascular endothelial activation induced in vivo by inflammatory stimuli to isolate a subpopulation of endothelium for in vitro study. METHODS: Immunohistochemical analyses of the pulmonary vasculature of mice treated systemically with gram-negative bacterial endotoxin (LPS) demonstrated selective expression of VCAM-1 (CD106) in the endothelial lining of small collecting veins, venules, septal capillaries, and, infrequently, small arteries, which was not observed in control mice. Single cell suspensions prepared by enzymatic dissociation of peripheral lobular tissues dissected from the lungs of LPS-stimulated mice were incubated with a phycoerythrin-conjugated antimouse VCAM-1 monoclonal antibody (MK 1.91). Cells expressing this antigen were isolated by sterile fluorescence-activated cell sorting (FACS). Positive cell populations were collected and cultured for 1-2 weeks. When confluent, these primary cultures were further FACS enriched for endothelium, positively selecting for cells incorporating a fluorescent derivative of acetylated low density lipoprotein (Di-I-Ac-LDL). RESULTS: The resulting population of cells (mouse lung endothelial cells, MLEC) were uniformly positive for the endothelial markers von Willebrand factor, thrombomodulin, and Dil-Ac-LDL uptake. MLEC readily formed tube-like structures when cultured on Matrigel and spontaneously demonstrated a sprouting phenotype on fibronectin or collagen matrices. MLEC retained responsiveness to cytokines (IL-1 alpha, IL-1 beta, TNF alpha, IFN gamma) up to at least eight passages from primary culture and demonstrated upregulation of E-selectin (CD62E) and P-selectin (CD62P) mRNA as early as 2 hr after LPS stimulation. Characteristic temporal expression patterns of cell surface E-selectin (maximal at 4 hr and declining toward baseline by 24 hr), VCAM-1 (maximal at 6-8 hr and remaining elevated for 24-48 hr), and ICAM-1 (maximal at 6-8 hr and maintained at 24 hr) were observed when cultured MLEC were treated with recombinant murine TNF alpha or recombinant human (rh) IL-1 alpha or rhIL-1 beta. The rolling, adhesion, and transmigration of human polymorphonuclear leukocytes was markedly increased on cytokine-activated MLEC monolayers under defined flow conditions. CONCLUSION: The strategy of activation-dependent isolation allows for the reproducible selection of a specific subset of microvascular endothelial cells for in vitro study. This experimental approach should further facilitate study of the functional heterogeneity of endothelium and its pathophysiologic dysfunction.


Assuntos
Endotélio Vascular/citologia , Lipopolissacarídeos/farmacologia , Pulmão/irrigação sanguínea , Molécula 1 de Adesão de Célula Vascular/biossíntese , Animais , Separação Celular , Células Cultivadas , Citocinas/farmacologia , Citometria de Fluxo , Humanos , Imuno-Histoquímica , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Estimulação Química , Regulação para Cima
14.
Am J Physiol ; 267(4 Pt 2): H1549-56, 1994 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7943401

RESUMO

The region of the rostral ventrolateral medulla (RVLM) plays an important role in central nervous system regulation of cardiovascular function. The initial purpose of these studies was to determine whether synaptic activation of excitatory amino acid (EAA) receptors in the RVLM might mediate central pressor responses. Blockade of EAA receptors in the RVLM with kynurenic acid abolished pressor responses evoked by stimulation of sciatic nerve afferents but had no effect on increases in arterial pressure produced by stimulation of hypothalamic sites. To determine whether synaptic transmission in the RVLM, independent of EAA receptor activation, was a prerequisite for the production of hypothalamic pressor responses, axonal conduction and/or synaptic transmission were pharmacologically interrupted in the RVLM. Blockade of synaptic transmission with muscimol or kainic acid attenuated, but did not eliminate, hypothalamic pressor responses. Concurrent blockade of synaptic and axonal transmission in the RVLM with lidocaine produced the greatest reduction of hypothalamic pressor responses. Collectively, these results suggest that central pressor responses are not uniformly mediated by synaptic activation of neurons within the RVLM. Instead, a combination of synaptic transmission and axonal conduction within and possibly outside the region of the RVLM may be required for the production of many centrally mediated pressor responses.


Assuntos
Pressão Sanguínea/fisiologia , Hipotálamo/fisiologia , Bulbo/fisiologia , Receptores de Glutamato/fisiologia , Animais , Axônios/efeitos dos fármacos , Axônios/fisiologia , Pressão Sanguínea/efeitos dos fármacos , Mapeamento Encefálico , Estimulação Elétrica , Feminino , Ácido Caínico/administração & dosagem , Ácido Caínico/farmacologia , Ácido Cinurênico/administração & dosagem , Ácido Cinurênico/farmacologia , Lidocaína/administração & dosagem , Lidocaína/farmacologia , Microinjeções , Muscimol/administração & dosagem , Muscimol/farmacologia , Ratos , Ratos Sprague-Dawley , Nervo Isquiático/fisiologia , Sinapses/fisiologia
15.
J Auton Nerv Syst ; 43(3): 231-9, 1993 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-7690055

RESUMO

The role of excitatory amino acid receptors in the rostral ventrolateral medulla (RVLM) in mediating a somatosympathetic pressor response (SPR) was studied. Rats were anesthetized with urethane, bilaterally vagotomized, paralyzed and respirated. Increases in mean arterial pressure were evoked by 10-s trains of electrical stimulation of sciatic nerve afferents before and after bilateral microinjections into the RVLM of the N-methyl-D-aspartic acid (NMDA) receptor antagonist D-2-amino-7-phosphono-heptanoic acid (D-AP7) or the non-NMDA receptor antagonist 6,7-dinitroquinoxaline-2,3-dione (DNQX). DNQX reversed or markedly attenuated the SPR. In contrast, the SPR was not significantly altered by blockade of NMDA receptors in the RVLM with D-AP7. However, prior administration of D-AP7 prevented reversal of the SPR by DNQX, while administration of D-AP7 after DNQX partially restored the SPR. These results indicate that pressor responses evoked by electrical stimulation of sciatic nerve afferents require synaptic activation of non-NMDA receptors in the RVLM. A somatic depressor response, revealed after blockade of non-NMDA receptors within the RVLM, may be mediated by activation of NMDA receptors in this region of the brainstem.


Assuntos
2-Amino-5-fosfonovalerato/análogos & derivados , Pressão Sanguínea/fisiologia , Bulbo/fisiologia , Receptores de Aminoácido/fisiologia , Sistema Nervoso Simpático/fisiologia , Aminoácidos/farmacologia , Animais , Pressão Sanguínea/efeitos dos fármacos , Estimulação Elétrica , Feminino , Histocitoquímica , Ácido Ibotênico/análogos & derivados , Ácido Ibotênico/farmacologia , Ácido Caínico/farmacologia , Bulbo/anatomia & histologia , Neurônios Aferentes/fisiologia , Quinoxalinas/farmacologia , Ratos , Ratos Sprague-Dawley , Receptores de Aminoácido/antagonistas & inibidores , Receptores de Aminoácido/efeitos dos fármacos , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Receptores de N-Metil-D-Aspartato/efeitos dos fármacos , Receptores de N-Metil-D-Aspartato/fisiologia , Nervo Isquiático/fisiologia , Sistema Nervoso Simpático/efeitos dos fármacos , Vagotomia , Ácido alfa-Amino-3-hidroxi-5-metil-4-isoxazol Propiônico
16.
J Immunol ; 149(6): 2163-71, 1992 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-1381398

RESUMO

We have previously reported that cytokine- or LPS-activated human umbilical vein endothelial cell (HUVEC) monolayers secrete IL-8 that can act as a neutrophil-selective adhesion inhibitor. In our study we investigated the mechanisms involved in the leukocyte adhesion inhibitory action of IL-8. The leukocyte adhesion inhibitory effect appears to be mediated by the action of IL-8 on the neutrophil, does not involve down-regulation of relevant endothelial adhesion molecules such as endothelial-leukocyte adhesion molecule-1 or intercellular adhesion molecule-1, and is quantitatively similar in different endothelial activation states that are predominantly endothelial-leukocyte adhesion molecule-1 dependent or intercellular adhesion molecule-1 dependent. In addition to inhibiting the attachment of freshly isolated peripheral blood neutrophils to cytokine-activated HUVEC monolayers, IL-8 also promoted a rapid detachment of tightly adherent neutrophils from activated HUVEC, and abolished neutrophil transendothelial migration. Certain other chemoattractants, including FMLP and C5a, had similar inhibitory actions, indicating IL-8 was not unique in its ability to inhibit various neutrophil-endothelial interactions. In contrast, two other neutrophil agonists 1-0-alkyl-2-acetyl sn-glycero-3-phosphocholine and granulocyte-macrophage-CSF, which, like IL-8, are produced by activated HUVEC, as well as the leukocyte-derived chemoattractant leukotriene B4, exerted minimal inhibitory effects on adhesion. Regardless of their ability to modulate neutrophil-endothelial cell adhesion, all these agents induced altered leukocyte surface expression of functionally important adhesion molecules, including loss of L-selectin (leukocyte adhesion molecule-1, LECAM-1) and increase in CD11b/CD18. Thus, although the above agonists have been characterized primarily as chemoattractants, our findings demonstrate that these agents can exert a wide range of modulatory effects on neutrophil-endothelial adhesive interactions.


Assuntos
Adesão Celular/efeitos dos fármacos , Fatores Quimiotáticos/farmacologia , Endotélio Vascular/citologia , Interleucina-8/farmacologia , Neutrófilos/citologia , Antígenos CD/metabolismo , Antígenos CD18 , Moléculas de Adesão Celular/metabolismo , Células Cultivadas , Quimiotaxia/efeitos dos fármacos , Citocinas/farmacologia , Selectina E , Antígenos HLA/metabolismo , Humanos , Técnicas In Vitro , Molécula 1 de Adesão Intercelular , Selectina L , Antígeno de Macrófago 1/metabolismo
17.
J Leukoc Biol ; 52(1): 43-51, 1992 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-1640174

RESUMO

Interleukin-8 (IL-8) induces diverse biological responses in neutrophils, including inhibition of adhesion to cytokine-activated endothelium, which we have termed the leukocyte adhesion inhibition (LAI) effect. Pretreatment of neutrophils with cytochalasin B abolished the LAI effect of IL-8, suggesting a microfilament-dependent mechanism. Interleukin-8 induced a rapid increase (less than or equal to 15 s) in the polymerization of actin filaments in human neutrophils that was blocked by pretreatment with cytochalasin B. F-actin depolymerization occurred gradually at a rate inversely proportional to IL-8 concentration. This temporal pattern of actin polymerization-depolymerization was similar to that induced by other chemotactic factors such as C5a and N-formylmethionyl-leucyl-phenylalanine, which also exhibit a marked LAI effect, but the lipid mediators, leukotriene B4 and platelet-activating factor, lack any significant LAI effect. Scanning confocal microscopy demonstrated that neutrophil actin microfilaments undergo a dramatic rearrangement prior to detachment of the neutrophil from a surface. We suggest that the ability of IL-8 and certain other leukocyte agonists to regulate the actin polymer network of neutrophils may play an important role in adhesive interactions with the vascular endothelium.


Assuntos
Actinas/química , Interleucina-8/farmacologia , Neutrófilos/química , Fatores Quimiotáticos/farmacologia , Complemento C5a/farmacologia , Citocalasina B/farmacologia , Citoesqueleto/efeitos dos fármacos , Endotélio Vascular/efeitos dos fármacos , Humanos , Teste de Inibição de Aderência Leucocítica , N-Formilmetionina Leucil-Fenilalanina/farmacologia , Neutrófilos/citologia , Polímeros , Conformação Proteica/efeitos dos fármacos
18.
J Immunol ; 146(5): 1617-25, 1991 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-1704400

RESUMO

rIL-1 beta treatment of cultured human endothelial cells (HEC) promotes polymorphonuclear leukocyte (PMN) adhesion and transmigration. Using in vitro quantitative monolayer adhesion and videomicroscopic transmigration assays, we have examined the contributions of endothelial-leukocyte adhesion molecule-1 (ELAM-1), intercellular adhesion molecule-1 (ICAM-1), and the leukocyte adhesion complex, CD11/CD18, to these processes. Maximal enhancement of PMN adhesion and transmigration were observed after 4 h of rIL-1 beta treatment, when surface expression of ELAM-1 had peaked and ICAM-1 was modestly increased. Blocking mAb directed to either ELAM-1 or ICAM-1 inhibited greater than 90% of the up-regulated PMN transmigration. Blocking mAb directed to either CD11a/CD18 (LFA-1, a ICAM-1 counter-receptor), CD11b/CD18 (Mo-1), or CD18 (common beta 2-integrin) also blocked greater than 90% of PMN transmigration. At later time points (24 or 48 h), ELAM-1 surface expression was markedly decreased, whereas ICAM-1 expression was increased over the 4-h level; PMN adhesion remained elevated (approximately 50 to 60% of 4 h level), but transmigration returned to levels seen with unactivated HEC. These data indicate that PMN interaction with at least two distinct HEC adhesion molecules is necessary for transendothelial migration and suggests that PMN adhesion and transmigration, although interrelated, are mechanistically distinct processes.


Assuntos
Moléculas de Adesão Celular/fisiologia , Endotélio Vascular/fisiologia , Neutrófilos/fisiologia , Antígenos CD/fisiologia , Antígenos CD18 , Adesão Celular/fisiologia , Moléculas de Adesão Celular/biossíntese , Movimento Celular/fisiologia , Selectina E , Endotélio Vascular/metabolismo , Humanos , Técnicas In Vitro , Molécula 1 de Adesão Intercelular , Interleucina-1/fisiologia , Cinética , Receptores de Adesão de Leucócito/fisiologia
19.
J Immunol ; 145(9): 3033-40, 1990 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-2212672

RESUMO

We have recently shown that endothelial cell-derived IL-8 inhibits neutrophil adhesion to IL1-beta-activated human umbilical vein endothelial cell monolayers. IL-8 secreted by T lymphocytes or monocytes has been characterized as a promoter of neutrophil degranulation and chemotaxis. The IL-8 isolated from each of these cell types is a mixture of two IL-8 polypeptides, one consisting of 72 amino acids (herein called [ser-IL-8]72) and the other 77 amino acids (an N-terminal extended form herein called [ala-IL-8]77). IL-8 derived from T lymphocytes and monocytes is predominantly [ser-IL-8]72, whereas endothelial-derived IL-8 is highly enriched (greater than 80%) in [ala-IL-8]77. We address the relationship and activities of these two forms of IL-8 using recombinant proteins expressed by both mammalian cells and Escherichia coli. Thrombin was found to efficiently convert [ala-IL-8]77 to [ser-IL-8]72. In contrast, urokinase and tissue-type plasminogen activator were unable to cleave [ala-IL-8]77, and trypsin generated multiple IL-8 cleavage fragments. In competitive binding assays using 125I[ala-IL-8]77 neutrophils exhibited a twofold preference for [ser-IL-8]72 over [ala-IL-8]77. Both forms of IL-8 inhibited neutrophil adhesion to IL-1-beta-activated HUVEC monolayers by up to 90%. However, [ser-IL-8]72 was approximately 10-fold more potent than [ala-IL-8]77 in these assays (ED50 approximately 0.3 nM for [ser-IL-8]72 vs approximately 3 nM for [ala-IL-8]77. Both forms of IL-8 promoted degranulation of cytochalasin B-treated neutrophils [[ser-IL-8]72 (ED50 greater than 10 nM) was two- to three-fold more potent than [ala-IL-8]77], although in this regard they were less active than FMLP. Our data suggest that [ala-IL-8]77 and [ser-IL-8]72 have qualitatively similar and potentially complex biological activities, and that full activation of IL-8 requires cleavage to the [ser-IL-8]72 form. In the case of inflamed endothelial cells this activation could be mediated by thrombin generated in the procoagulant environment associated with these cells.


Assuntos
Endotélio Vascular/metabolismo , Interleucina-8/metabolismo , Leucócitos/fisiologia , Neutrófilos/fisiologia , Adesão Celular , Degranulação Celular/efeitos dos fármacos , Citocalasina B/farmacologia , Endotélio Vascular/citologia , Humanos , Técnicas In Vitro , Interleucina-1/farmacologia , Interleucina-8/química , Interleucina-8/genética , Interleucina-8/isolamento & purificação , N-Formilmetionina Leucil-Fenilalanina/farmacologia , Neutrófilos/citologia , Elastase Pancreática/metabolismo , Receptores Imunológicos/fisiologia , Receptores de Interleucina-8A , Proteínas Recombinantes , Relação Estrutura-Atividade , Trombina/metabolismo , Transfecção
20.
Am J Hematol ; 31(3): 211-2, 1989 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-2500852

RESUMO

A patient with pure red cell aplasia and expansion of the peripheral blood natural killer (NK) cell population is described. Despite normal absolute and differential leukocyte counts, NK cells were increased at diagnosis and at relapse. Furthermore, these cells were not morphologically recognizable on the peripheral blood smear examination. A favorable clinical response to glucocorticoid therapy was accompanied by a decrease in NK cells.


Assuntos
Células Matadoras Naturais , Linfocitose/complicações , Prednisona/uso terapêutico , Aplasia Pura de Série Vermelha/complicações , Azatioprina/uso terapêutico , Transfusão de Sangue , Transfusão de Eritrócitos , Feminino , Humanos , Linfócitos/classificação , Pessoa de Meia-Idade , Aplasia Pura de Série Vermelha/tratamento farmacológico , Aplasia Pura de Série Vermelha/terapia
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