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1.
Clin J Oncol Nurs ; 20(5): 560-3, 2016 10 01.
Article in English | MEDLINE | ID: mdl-27668378

ABSTRACT

This study aimed to describe the contemporary role of the oncology nurse throughout the entire cancer shared decision-making (SDM) process. Study participants consisted of 30 nurses and nurse practitioners who are actively involved in direct care of patients with cancer in the inpatient or outpatient setting. The major themes that emerged from the content analysis are: oncology nurses have various roles at different time points and settings of cancer SDM processes; patient education, advocacy, and treatment side effects management are among the top nursing roles; oncology nurses value their participation in the cancer SDM process; oncology nurses believe they have a voice, but with various degrees of influence in actual treatment decisions; nurses' level of disease knowledge influences the degree of participation in cancer SDM; and the nursing role during cancer SDM can be complicated and requires flexibility.
.


Subject(s)
Decision Making , Nurse's Role , Oncology Nursing/standards , Patient Participation , Practice Guidelines as Topic , Professional Role , Adult , Aged , Female , Humans , Male , Middle Aged
2.
West J Nurs Res ; 38(10): 1282-97, 2016 10.
Article in English | MEDLINE | ID: mdl-27194634

ABSTRACT

This study aimed to identify the barriers and promoters for participation in cancer treatment decision in the era of shared decision-making (SDM) process. A qualitative design was utilized. Nineteen nurses and 11 nurse practitioners from oncology inpatient and outpatient settings participated in semi-structured interviews. Data were analyzed using directed content analysis. The findings include practice barrier, patient barrier, institutional policy barrier, professional barrier, scope of practice barrier, insurance coverage barrier, and administrative barrier. Multidisciplinary team approach, having a nursing voice during SDM, high level of knowledge of the disease and treatment, and personal valuation of SDM participation were perceived as promoters. Oncology nurses and nurse practitioners face many barriers to their participation during SDM. Organizational support and system-wide culture of SDM are essential to achieve better cancer treatment decisions outcome. Additional studies are needed to determine the factors that can promote more participation among nurses and nurse practitioners.


Subject(s)
Decision Making , Oncology Nursing , Patient Care Planning , Adult , Female , Humans , Interviews as Topic , Male , Middle Aged , Neoplasms/therapy , Nurse's Role , Qualitative Research
3.
Appl Nurs Res ; 28(3): 222-8, 2015 Aug.
Article in English | MEDLINE | ID: mdl-26094879

ABSTRACT

AIM: To understand the influential factors related to sexual behaviors among Asian-American adolescents and to evaluate common factors across successful sexual education programs for this population. BACKGROUND: Despite a rapid increase in cases of STIs/HIV among Asian-American populations, there remains a need for a comprehensive understanding of the influential factors related to risky sexual behaviors for this population. METHODS: An integrative literature review was conducted. Peer-reviewed articles and government resources were analyzed. RESULTS: Five influential factors were identified: family-centered cultural values, parental relationship, acculturation, gender roles, and lack of knowledge and information about sex and STIs. Only two sexual educational programs met the inclusion criteria and provided evidence towards effectiveness: Safer Choices and Seattle Social Development Project. CONCLUSIONS: The findings of this study indicate an urgent need for culturally sensitive sexual education programs that incorporate the identified influential factors, especially cultural values in order to reduce risky sexual behaviors among Asian-American adolescents.


Subject(s)
Adolescent Behavior , Asian , HIV Infections/epidemiology , Sexual Behavior , Sexually Transmitted Diseases/epidemiology , Adolescent , HIV Infections/prevention & control , Humans , Program Evaluation , Risk Factors , Sexually Transmitted Diseases/prevention & control , United States
4.
Mol Biol Cell ; 26(14): 2673-84, 2015 Jul 15.
Article in English | MEDLINE | ID: mdl-25995376

ABSTRACT

Contact-mediated inhibition of cell proliferation is an essential part of organ growth control; the transcription coactivator Yes-associated protein (YAP) plays a pivotal role in this process. In addition to phosphorylation-dependent regulation of YAP, the integral membrane protein angiomotin (AMOT) and AMOT family members control YAP through direct binding. Here we report that regulation of YAP activity occurs at the endosomal membrane through a dynamic interaction of AMOT with an endosomal integral membrane protein, endotubin (EDTB). EDTB interacts with both AMOT and occludin and preferentially associates with occludin in confluent cells but with AMOT family members in subconfluent cells. EDTB competes with YAP for binding to AMOT proteins in subconfluent cells. Overexpression of the cytoplasmic domain or full-length EDTB induces translocation of YAP to the nucleus, an overgrowth phenotype, and growth in soft agar. This increase in proliferation is dependent upon YAP activity and is complemented by overexpression of p130-AMOT. Furthermore, overexpression of EDTB inhibits the AMOT:YAP interaction. EDTB and AMOT have a greater association in subconfluent cells compared with confluent cells, and this association is regulated at the endosomal membrane. These data provide a link between the trafficking of tight junction proteins through endosomes and contact-inhibition-regulated cell growth.


Subject(s)
Contact Inhibition/physiology , Endosomes/metabolism , Intercellular Signaling Peptides and Proteins/metabolism , Membrane Glycoproteins/metabolism , Microfilament Proteins/metabolism , Signal Transduction , Trans-Activators/metabolism , Animals , Dogs , Madin Darby Canine Kidney Cells , Protein Binding
5.
Traffic ; 11(6): 856-66, 2010 Jun.
Article in English | MEDLINE | ID: mdl-20214753

ABSTRACT

The establishment of tight junctions and cell polarity is an essential process in all epithelia. Endotubin is an integral membrane protein found in apical endosomes of developing epithelia when tight junctions and epithelial polarity first arise. We found that the disruption of endotubin function in cells in culture by siRNA or overexpression of the C-terminal cytoplasmic domain of endotubin causes defects in organization and function of tight junctions. We observe defects in localization of tight junction proteins, reduced transepithelial resistance, increased lanthanum penetration between cells and reduced ability of cells to form cysts in three-dimensional culture. In addition, in cells overexpressing the C-terminal domain of endotubin, we observe a delay in re-establishing the normal distribution of endosomes after calcium switch. These results suggest that endotubin regulates trafficking of polarity proteins and tight junction components out of the endosomal compartment, thereby providing a critical link between a resident protein of apical endosomes and tight junctions.


Subject(s)
Endosomes/metabolism , Epithelium/metabolism , Tight Junctions/metabolism , Animals , Calcium/chemistry , Cytoplasm/metabolism , Dogs , Green Fluorescent Proteins/chemistry , Membrane Glycoproteins/chemistry , Membrane Proteins/metabolism , Microscopy, Confocal/methods , Microscopy, Electron, Transmission/methods , Phosphoproteins/metabolism , Protein Structure, Tertiary , RNA, Small Interfering/metabolism , Transfection , Zonula Occludens-1 Protein
6.
PLoS Med ; 4(9): e269, 2007 Sep.
Article in English | MEDLINE | ID: mdl-17803352

ABSTRACT

BACKGROUND: The acute respiratory distress syndrome (ARDS), a clinical complication of severe acute lung injury (ALI) in humans, is a leading cause of morbidity and mortality in critically ill patients. ALI is characterized by disruption of the lung alveolar-capillary membrane barrier and resultant pulmonary edema associated with a proteinaceous alveolar exudate. Current specific treatment strategies for ALI/ARDS are lacking. We hypothesized that mesenchymal stem cells (MSCs), with or without transfection with the vasculoprotective gene angiopoietin 1 (ANGPT1) would have beneficial effects in experimental ALI in mice. METHODS AND FINDINGS: Syngeneic MSCs with or without transfection with plasmid containing the human ANGPT1 gene (pANGPT1) were delivered through the right jugular vein of mice 30 min after intratracheal instillation of lipopolysaccharide (LPS) to induce lung injury. Administration of MSCs significantly reduced LPS-induced pulmonary inflammation, as reflected by reductions in total cell and neutrophil counts in bronchoalveolar lavage (BAL) fluid (53%, 95% confidence interval [CI] 7%-101%; and 60%, CI 4%-116%, respectively) as well as reducing levels of proinflammatory cytokines in both BAL fluid and lung parenchymal homogenates. Furthermore, administration of MSCs transfected with pANGPT1 resulted in nearly complete reversal of LPS-induced increases in lung permeability as assessed by reductions in IgM and albumin levels in BAL (96%, CI 6%-185%; and 74%, CI 23%-126%, respectively). Fluorescently tagged MSCs were detected in the lung tissues by confocal microscopy and flow cytometry in both naïve and LPS-injured animals up to 3 d. CONCLUSIONS: Treatment with MSCs alone significantly reduced LPS-induced acute pulmonary inflammation in mice, while administration of pANGPT1-transfected MSCs resulted in a further improvement in both alveolar inflammation and permeability. These results suggest a potential role for cell-based ANGPT1 gene therapy to treat clinical ALI/ARDS.


Subject(s)
Angiopoietin-1/biosynthesis , Angiopoietin-1/genetics , Gene Expression Regulation/physiology , Lipopolysaccharides/toxicity , Mesenchymal Stem Cell Transplantation/methods , Mesenchymal Stem Cells/metabolism , Respiratory Distress Syndrome/prevention & control , Angiopoietin-1/administration & dosage , Animals , Genetic Therapy/methods , Humans , Male , Mice , Mice, Inbred C57BL , Respiratory Distress Syndrome/chemically induced , Respiratory Distress Syndrome/genetics
7.
Am J Respir Crit Care Med ; 175(10): 1014-26, 2007 May 15.
Article in English | MEDLINE | ID: mdl-17322110

ABSTRACT

RATIONALE: The acute respiratory distress syndrome is a significant cause of morbidity and mortality in critically ill patients. Angiopoietin-1 (Ang-1), a ligand for the endothelial Tie2 receptor, is an endothelial survival and vascular stabilization factor that reduces endothelial permeability and inhibits leukocyte-endothelium interactions. OBJECTIVES: We hypothesized that Ang-1 counteracts vascular inflammation and pulmonary vascular leak in experimental acute lung injury. METHODS: We used cell-based gene therapy in a rat model of ALI. Transgenic mice overexpressing Ang-1 or deficient in the Tie2 receptor were also studied to better elucidate the mechanisms of protection. MEASUREMENTS AND MAIN RESULTS: The present report provides data that support a strong protective role for the Ang-1/Tie2 system in two experimental models of LPS-induced acute lung injury. In a rat model, cell-based Ang-1 gene transfer improved morphological, biochemical, and molecular indices of lung injury and inflammation. These findings were confirmed in a gain-of-function conditional, targeted transgenic mouse model, in which Ang-1 reduced endothelial cell activation and the expression of adhesion molecules, associated with a marked improvement in airspace inflammation and intraalveolar septal thickening. Moreover, heterozygous Tie2-deficient mice demonstrated enhanced evidence of lung injury and increased early mortality. CONCLUSIONS: These results support a critical role for the Ang-1/Tie2 axis in modulating the pulmonary vascular response to lung injury and suggest that Ang-1 therapy may represent a potential new strategy for the treatment and/or prevention of acute respiratory distress syndrome in critically ill patients.


Subject(s)
Angiopoietin-1/genetics , Genetic Therapy/methods , Respiratory Distress Syndrome/therapy , Animals , Cell Adhesion/genetics , Cell Adhesion Molecules/genetics , Cell Adhesion Molecules/metabolism , Cytokines/metabolism , Female , Fibroblasts/transplantation , Gene Expression , Lipopolysaccharides/toxicity , Male , Mice , Mice, Transgenic , Rats , Rats, Inbred F344 , Receptor, TIE-2/genetics , Respiratory Distress Syndrome/pathology
8.
Exp Biol Med (Maywood) ; 231(6): 985-91, 2006 Jun.
Article in English | MEDLINE | ID: mdl-16741035

ABSTRACT

Endothelin-1 (ET-1) is increasingly recognized as a proinflammatory mediator in various diseases, such as atherosclerosis and acute respiratory distress syndrome (ARDS). Angiopoietin-1 (Ang-1), a ligand of the endothelial receptor Tie2, inhibits endothelial apoptosis, reduces vascular leakage, and suppresses the induction of inflammatory markers, indicating that it has diverse vasoprotective, anti-inflammatory actions. Thus, we examined the effects of Ang-1 on ET-1 production in vitro and in vivo and investigated cell-based gene transfer of Ang-1 in a rat model of lipopolysaccharide (LPS)-induced ARDS. Cultured human endothelial cells were treated with recombinant Ang-1 with or without tumor necrosis factor-alpha (TNF-alpha) (100 U/ml). ET-1 release into the culture medium after 24 hrs was determined by enzyme-linked immunosorbent assay. Levels of preproendothelin-1 (ppET-1) mRNA were measured by quantitative reverse transcription-polymerase chain reaction. Fisher344 rats were subjected to cell-based gene transfer to the lung circulation by injecting syngeneic fibroblasts transfected with Ang-1 cDNA or a null plasmid vector. After 24 hrs, LPS (100 microg/kg body wt) was instilled intratracheally to induce pulmonary inflammation. Bronchoalveolar lavage was performed 6 hrs later, and lungs were harvested for histologic and molecular analyses. ET-1 release from cultured endothelial cells was dose-dependently reduced by Ang-1, which also prevented induction of ET-1 release by TNF-alpha (P < 0.05). RNA expression of ppET-1 was similarly reduced. In LPS-challenged lungs, ppET-1 RNA was induced 3.4-fold, and ET-1 protein in lavage fluid was increased 5.6-fold (P < 0.05). Ang-1 gene transfer attenuated the LPS-induced increases in ppET-1 RNA and lavage ET-1 protein by 34% and 33%, respectively (P < 0.05). The downregulation of ET-1 correlated with the amelioration of pulmonary inflammation, as indicated by reductions in leukocyte infiltration (by 43%) and intra-alveolar septal thickening (by 40%). These results show that ET-1 transcript and protein levels are downregulated by Ang-1 in both in vitro and in vivo systems and that cell-based Ang-1 gene transfer markedly ameliorated inflammation in vivo in an experimental model of ARDS. Thus, cell-based gene transfer of Ang-1 may provide a novel treatment strategy for ARDS by attenuating vascular inflammation via suppression of ET-1.


Subject(s)
Angiopoietin-1/pharmacology , Endothelin-1/metabolism , Gene Expression Regulation/drug effects , Angiopoietin-1/genetics , Angiopoietin-1/therapeutic use , Animals , Cells, Cultured , Culture Media/analysis , Dose-Response Relationship, Drug , Down-Regulation/drug effects , Endothelin-1/analysis , Endothelium, Vascular/cytology , Fibroblasts/cytology , Fibroblasts/drug effects , Gene Transfer Techniques , Inflammation/genetics , Lung Diseases/drug therapy , Lung Diseases/pathology , Male , Random Allocation , Rats , Rats, Inbred F344 , Skin/cytology
9.
Can J Surg ; 47(5): 352-8, 2004 Oct.
Article in English | MEDLINE | ID: mdl-15540688

ABSTRACT

BACKGROUND: Ischemic preconditioning (IPC) has been found in animals to have a protective effect against future ischemic injury to muscle tissue. Such injury is unavoidable during some surgical procedures. To determine whether chronic ischemia in the lower extremities would imitate IPC and reduce ischemic injury during vascular surgery, we designed a controlled clinical study. PATIENTS AND METHODS: Two groups of patients at a university-affiliated medical centre with chronic lower-extremity ischemia served as models of IPC: 6 patients awaiting femoral distal bypass (FDB) and 4 scheduled for aortobifemoral (ABF) bypass grafting for aortoiliac occlusive disease. Seven patients undergoing elective open repair of an infrarenal abdominal aortic aneurysm (AAA) were chosen as non-IPC controls. Three hematologic indicators of skeletal-muscle injury, lactate dehydrogenase (LDH), creatine kinase (CK) and myoglobin, were measured before placement of the proximal clamp, during surgical ischemia, immediately upon reperfusion, 15 minutes after and 1 hour after reperfusion, and during the first, second and third postoperative days. RESULTS: Baseline markers of skeletal-muscle injury were similar in all groups. In postreperfusion samples, concentrations of muscle-injury markers were significantly lower in the 2 PC groups than in the control group. For example, at day 2, LDH levels were increased by about 30% over baseline measures in the elective AAA (control) group, whereas levels in the FDB and ABF groups remained statistically unchanged from baseline. Myoglobin in controls had increased by 977%, but only by 160% in the FDB and 528% in the ABF groups. CK levels, in a similar trend, were 1432% higher in the control group and only 111% (FDB) and 1029% (ABF) in the study groups. Taken together, these data represent a significant level of protection. CONCLUSIONS: Patients with chronic lower-extremity ischemia suffered less severe ischemic injury after a period of acute ischemia than those with acute ischemia alone. Ischemic preconditioning is one proposed mechanism to help explain this protective effect.


Subject(s)
Arterial Occlusive Diseases/surgery , Blood Vessel Prosthesis Implantation/adverse effects , Ischemia/physiopathology , Ischemic Preconditioning , Lower Extremity/blood supply , Muscle, Skeletal/blood supply , Reperfusion Injury/prevention & control , Aged , Arterial Occlusive Diseases/complications , Chronic Disease , Constriction , Female , Humans , Ischemia/etiology , Male , Middle Aged , Models, Cardiovascular , Reperfusion Injury/etiology , Treatment Outcome
10.
Microcirculation ; 11(7): 587-95, 2004.
Article in English | MEDLINE | ID: mdl-15513868

ABSTRACT

OBJECTIVES: Adenovirus-mediated gene therapy is being investigated with increasing success for future treatment of autoimmune diseases. However, the use of adenoviruses is still limited by inflammatory and immune responses in the target organ. Previous work by the authors' laboratory established that the adenovirus encoding inducible heme oxygenase (Ad-HO-1) does not elicit the acute hepatic inflammation normally caused by adenoviruses, inviting further investigation in models of severe inflammation. Concurrently, there is increasing evidence for an endogenous protective role for heme oxygenase (HO) in the liver during the systemic inflammatory response syndrome (SIRS). Building on our previous results, this study investigated the effect of Ad-HO-1 pretreatment on remote liver injury during normotensive SIRS, induced by bilateral hind limb ischemia and reperfusion. METHODS: Microvascular perfusion and hepatocyte death were quantified using established intravital videomicroscopy techniques. Hepatocellular injury and liver function were assessed using blood-borne indicators. RESULTS: Microvascular perfusion deficits and increased hepatocyte death occurred following limb ischemia and 3 h of reperfusion in vehicle-pretreated animals; however, Ad-HO-1 pretreatment prevented these deficits. In contrast, the increase in serum alanine transaminase levels was unaffected by Ad-HO-1 pretreatment. Serum bilirubin levels were increased during systemic inflammation, predominantly in the conjugated form; and, this increase was prevented by administration of Ad-HO-1. CONCLUSIONS: These data indicate that gene transfer of inducible HO is an effective method to protect the liver during SIRS, providing incentive for further investigation into gene therapy strategies exploiting this anti-inflammatory enzyme.


Subject(s)
Genetic Therapy , Heme Oxygenase (Decyclizing)/genetics , Liver/enzymology , Liver/injuries , Systemic Inflammatory Response Syndrome/therapy , Adenoviridae/genetics , Animals , Cell Death , Gene Transfer Techniques , Heme Oxygenase (Decyclizing)/metabolism , Heme Oxygenase-1 , Hepatocytes/pathology , Liver/blood supply , Liver/pathology , Male , Membrane Proteins , Mice , Mice, Inbred C57BL , Microcirculation/pathology , Microscopy, Video , Rats , Reperfusion Injury/pathology , Reperfusion Injury/prevention & control , Systemic Inflammatory Response Syndrome/etiology
11.
Surgery ; 136(1): 67-75, 2004 Jul.
Article in English | MEDLINE | ID: mdl-15232541

ABSTRACT

BACKGROUND: A protective role for endogenous heme oxygenase (HO) in the initiation of remote liver injury after limb ischemia/reperfusion has been established. This study expands on our previous work by investigating the role of endogenous HO on hepatocellular injury, hepatocyte death (necrotic and apoptotic), and microvascular perfusion at protracted post-reperfusion times. METHODS: Remote liver injury was studied after 1 hour of bilateral hind limb ischemia and 3, 6, or 24 hours of reperfusion in male C57BL6 mice. Inhibition of HO was achieved with the use of chromium mesoporphrin (CrMP). Established intravital videomicroscopy techniques were used to evaluate microvascular perfusion and hepatocyte death. Hepatocellular injury was quantified by serum alanine transaminase. Apoptosis was measured by using DNA laddering, Cell Death ELISA, and caspase-3 activity. RESULTS: Although significant perfusion deficits and hepatocellular injury/death occurred after 3 hours, progression of hepatocellular death beyond 6 hours was not observed. A transient increase in apoptosis was observed at 6 hours. By 24 hours, microvascular perfusion was completely restored. This lack of progression correlated with increased HO activity, observed throughout the protocol. Administration of CrMP reduced HO activity to sham nonstressed levels, and caused increased microvascular perfusion deficits, hepatocellular injury, and hepatocyte death over 24 hours. The transient increase in apoptosis was increased in duration and magnitude in CrMP-treated animals. CONCLUSIONS: These results suggest that endogenous HO activity prevents the progression of remote liver injury after limb ischemia/reperfusion.


Subject(s)
Heme Oxygenase (Decyclizing)/physiology , Liver Diseases/etiology , Microcirculation/physiopathology , Reperfusion Injury/physiopathology , Animals , Apoptosis/drug effects , Apoptosis/physiology , Cell Death/drug effects , Cell Death/physiology , Enzyme Inhibitors/pharmacology , Heme Oxygenase (Decyclizing)/antagonists & inhibitors , Heme Oxygenase (Decyclizing)/drug effects , Hepatocytes/drug effects , Hepatocytes/physiology , Hindlimb/blood supply , Male , Mesoporphyrins/pharmacology , Mice , Microcirculation/drug effects , Reperfusion Injury/complications
12.
J Surg Res ; 109(1): 62-7, 2003 Jan.
Article in English | MEDLINE | ID: mdl-12591237

ABSTRACT

OBJECTIVES: This study determined if ischemic tolerance occurs in oxidative skeletal muscle following a severe ischemia/reperfusion (I/R) insult and if such protection involves the induction of nitric oxide synthase (NOS). METHODS: The soleus muscle of male Wistar rats (250-350 g) was preconditioned (PC + I/R) using five cycles of ischemia (10 min) and reperfusion (10 min) or had no PC (I/R) and 24 h later 2 h no-flow ischemia was induced. Calcium dependent (cNOS) and independent (iNOS) NOS activities were determined from PC (n = 5), or sham (n = 5) and the role of iNOS was tested by application of aminoguanidine (AMG) (100 microM; n = 4) to the muscle bath. Direct measures of the number of perfused capillaries (Npc; #/mm) during 90-min reperfusion were obtained using intravital microscopy. Tissue injury was estimated using the fluorescent vital dyes ethidium bromide (E; labels injured cells) and bisbenzimide (B; labels all cells) and expressed as the ratio E/B. RESULTS: PC prevented microvascular flow deficits (Npc:I/R = 23.4 +/- 1.3 vs PC + I/R = 29.9 +/- 1.1) and resulted in a modest, but significant reduction (21%) in tissue injury (I/R = 0.82 +/- 0.03 vs PC + I/R = 0.64 +/- 0.04). PC led to a nine fold increase in iNOS activity, but decreased cNOS activity by 94% compared to sham. AMG prevented the parenchymal protection following PC, but had no effect on microvascular perfusion. CONCLUSIONS: Ischemic tolerance, 24 h following PC, preserved microvascular perfusion, but only modestly improved tissue viability in the soleus muscle.


Subject(s)
Ischemia/physiopathology , Ischemic Preconditioning , Muscle, Skeletal/blood supply , Nitric Oxide Synthase/metabolism , Animals , Calcium/pharmacology , Enzyme Inhibitors/pharmacology , Guanidines/pharmacology , Male , Microcirculation/physiopathology , Nitric Oxide Synthase/antagonists & inhibitors , Nitric Oxide Synthase Type II , Oxidation-Reduction , Rats , Rats, Wistar , Reperfusion , Reperfusion Injury/prevention & control
13.
J Hepatol ; 36(5): 624-30, 2002 May.
Article in English | MEDLINE | ID: mdl-11983445

ABSTRACT

BACKGROUND/AIMS: Heme oxygenase (HO) derived liver protection was tested in mice following 1 h bilateral hindlimb ischemia and either 1.5 or 3 h reperfusion. METHODS: Groups consisted of limb ischemia/reperfusion (I/R), sham (no I/R), I/R+chromium mesoporphyrin (I/R+CrMP;40 micromol/kg, i.p.), or I/R+hemin (10 mg/kg, i.p.). The vital dye propidium iodide (PI), was used to measure hepatocellular death (#/0.1 mm(3)), while the number of sinusoids perfused by red blood cells (SP(RBC)) were measured from the periportal (Pp) and pericentral (Pc) zones of liver acini using intravital microscopy. Whole organ injury was estimated from serum alanine aminotransferase (ALT). RESULTS: SP(RBC) reduced within 1.5 h with no further decline following 3 h. CrMP resulted in a dramatic loss of SP(RBC) following 3 h only. Hemin restored perfusion in both zones. Hepatocellular death and organ injury increased at 1.5 and 3 h. At 1.5 h, CrMP further increased cell death in the Pc zone, as well as whole organ injury, while hemin restored cell viability. Increased HO mRNA, protein and activity suggested induction within 3 h. CONCLUSIONS: HO does not protect perfusion during the early stage (1.5 h), but becomes increasingly important in preserving liver perfusion and cell viability during the later stage (3 h) of liver injury.


Subject(s)
Heme Oxygenase (Decyclizing)/metabolism , Liver Diseases/metabolism , Reperfusion Injury/metabolism , Alanine Transaminase/analysis , Animals , Blood Pressure , Cell Death , Extremities/blood supply , Heme Oxygenase (Decyclizing)/genetics , Heme Oxygenase-1 , Hemin/pharmacology , Hepatocytes/cytology , Liver/blood supply , Liver/cytology , Liver/enzymology , Liver Circulation , Male , Membrane Proteins , Mesoporphyrins/pharmacology , Mice , Mice, Inbred C57BL , RNA, Messenger/analysis
14.
J Physiol ; 540(Pt 3): 1013-21, 2002 May 01.
Article in English | MEDLINE | ID: mdl-11986386

ABSTRACT

The role of haem oxygenase (HO) in the hepatic accumulation of leukocytes in mice during the initiation of remote organ injury following normotensive limb ischaemia-reperfusion (I-R) was investigated. Remote organ injury was initiated by 1 h bilateral hindlimb ischaemia followed by either 1 or 1.5 h reperfusion (I-R) in male C57BL/6 mice. Mice were randomly assigned to either sham (no I-R, n = 4), I-R (n = 4 for both time points), I-R plus chromium mesoporphyrin (CrMP, n = 4) to inhibit HO or I-R plus haemin (n = 4) to increase HO. Leukocyte accumulation and leukocyte-endothelial interaction were directly measured using fluorescence intravital microscopy. Leukocytes were labelled via an injection of rhodamine 6G. In sinusoids the total number and the number of stationary leukocytes were assessed. In postsinusoidal venules the number of adherent and rolling leukocytes and the velocities of both red blood cells and leukocytes were measured. The total number of leukocytes increased in sinusoids of I-R mice reaching a plateau within 1 h compared with sham animals, while the number of stationary leukocytes progressively increased over the entire study period. Stationary leukocytes in sinusoids increased after 1 and 1.5 h of I-R following CrMP, while they were significantly reduced following haemin treatment compared to animals treated with I-R only. In postsinusoidal venules a progressive increase in adherent leukocytes also occurred. As observed in sinusoids, CrMP significantly increased, while haemin significantly reduced leukocyte adhesion. The number of rolling leukocytes increased after CrMP in both I-R groups (1 and 1.5 h). The velocities of rolling leukocytes declined following 1.5 h of I-R compared with sham. Haemin treatment of 1.5 h I-R animals restored the velocities back to sham levels. The calculated wall shear rates in postsinusoidal venules were significantly lower in all I-R groups in comparison to sham animals. Combination of 1.5 h I-R with CrMP resulted in the lowest shear rates of all I-R groups. The number of stationary leukocytes within sinusoids and adherent leukocytes in postsinusoidal venules were correlated to the corresponding alanine aminotransferase (ALT) levels. In conclusion, endogenous HO reduces leukocyte-endothelial interactions within the liver. Thus, endogenous HO activity provides an important mechanism controlling the hepatic inflammatory response during the initiation of remote organ injury following normotensive limb ischaemia-reperfusion.


Subject(s)
Extremities/blood supply , Heme Oxygenase (Decyclizing)/antagonists & inhibitors , Leukocytes/physiology , Liver/physiology , Reperfusion Injury/physiopathology , Alanine Transaminase/metabolism , Animals , Biomarkers , Cell Adhesion , Enzyme Inhibitors/pharmacology , Ischemia/physiopathology , Liver/pathology , Male , Mesoporphyrins/pharmacology , Mice , Mice, Inbred C57BL , Reperfusion , Venules/physiology
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