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BACKGROUND: Inspired by the US Choosing Wisely®, in 2016 the Swiss Society of General Internal Medicine released a list of five treatments or diagnostic tests used in the hospital and considered unnecessary based on not improving patient care and adding to health care costs. These "Smarter Medicine" recommendations were implemented in the Department of Internal Medicine, Uster Hospital, in August 2016. They were supported by lectures and weekly email communications. We analyzed the number of blood draws before and after implementation of the recommendation aimed at reducing blood tests. METHODS: This retrospective analysis was conducted in the Department of Internal Medicine, Uster Hospital, Canton of Zurich, Switzerland. Patients hospitalized in the 3 months before and after implementation were analyzed. RESULTS: A total of 2023 hospitalizations were analyzed. There was a significant decrease in the number of blood draws after introduction of the recommendation: before implementation, the median number of blood draws per patient was 4 (interquartile range [IQR], 2-7); after implementation, the median was 4 (IQR, 2-6; P = 0.002). Indeed, since 46% of the patients in the first group had more than four blood tests, this ratio decreased to 39% after implementation. DISCUSSION: Inappropriate blood draws may lead to anemia, patient discomfort and false-positive results. The simple and low-cost interventions used to implement "Smarter Medicine" have changed physician behavior by reducing the number of blood orders. These results are promising. Whether such recommendations will impact patient and clinical outcomes remains unknown; hence, further studies are needed to clarify this issue.
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BACKGROUND: In 2013 the Swiss Diagnosis Related Groups ((Swiss)-DRG) was implemented in Intensive Care Units (ICU). Its impact on hospitalizations has not yet been examined. We compared the number of ICU admissions, according to clinical severity and referring institution, and screened whether implementation of Swiss-DRG affected admission policy, ICU length-of-stay (ICU-LOS) or ICU mortality. METHODS: Retrospective, single centre, cohort study conducted at the University Hospital Zurich, Switzerland between January 2009 and end of September 2013. Demographic and clinical data was retrieved from a quality assurance database. RESULTS: Admissions (n = 17,231) before the introduction of Swiss-DRG were used to model expected admissions after DRG, and then compared to the observed admissions. Forecasting matched observations in patients with a high clinical severity admitted from internal units and external hospitals (admitted / predicted: 709 / 703, [95% Confidence Interval (CI), 658-748] and 302 / 332, [95% CI, 269-365] respectively). In patients with low severity of disease, in-house admissions became more frequent than expected and external admission were less frequent (admitted / predicted: 1972 / 1910, [95% CI, 1898-1940] and 436 / 518, [95% CI, 482-554] respectively). Various mechanisms related to Swiss-DRG may have led to these changes. DRG could not be linked to significant changes in regard to ICU-LOS and ICU mortality. CONCLUSIONS: DRG introduction had not affected ICU admissions policy, except for an increase of in-house patients with a low clinical severity of disease. DRG had neither affected ICU mortality nor ICU-LOS.
Subject(s)
Diagnosis-Related Groups , Hospital Mortality/trends , Intensive Care Units , Length of Stay/statistics & numerical data , Patient Admission/statistics & numerical data , Tertiary Care Centers , Adult , Aged , Female , Humans , Male , Middle Aged , Retrospective Studies , SwitzerlandABSTRACT
INTRODUCTION: Salmonella is a typical cause of aortitis, which is associated with high morbidity and mortality. In infrarenal disease, besides open surgery, endovascular aortic repair as an alternative treatment has been reported. To the best of our knowledge, we report the first successful endovascular aortic repair documented by necropsy to date. CASE PRESENTATION: A 67-year-old Caucasian man presented with low back pain, fever and positive blood cultures for Salmonella Enteritidis. A computed tomography scan showed an enlargement and intramural hematoma of the infrarenal aortic wall; a Salmonella aortitis was suspected and antimicrobial therapy initiated. Because of substantial comorbidities, endovascular aortic repair was favored over open surgery; postoperatively the antibiotic treatment was continued for 12 months. Post-mortem there were neither macroscopic nor microscopic signs of aortitis or graft infection. CONCLUSIONS: We could demonstrate by necropsy that endovascular aortic repair of infrarenal aortitis with prolonged pre- and postinterventional antibiotic therapy for 12 months was a minimally invasive alternative and should be considered in selected clinically stable patients with substantial co-morbidities.
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QUESTIONS UNDER STUDY: Community acquired pneumonia (CAP) and sepsis are leading causes of hospitalisation after admission to a medical emergency department (ED). Identifying these potentially life-threatening diseases is not always easy due to often unspecific or minimal symptoms. However, quick application of antibiotics is known to be crucial and is correlated with better outcome. The international guidelines of the joint commission suggest a 4 hour-rule for optimal quality of care in CAP and sepsis. In this study we assessed the door-to-needle time (DNT) in patients admitted to our ED with the diagnosis of CAP and/or sepsis. Furthermore we investigated the CRB-65 score, its clinical performance and its influence on DNT. METHODS: Retrospective observational study of all patients admitted and hospitalised through the ED of a Swiss hospital with the diagnosis of sepsis or pneumonia from June 2009 to June 2010 (n = 139). RESULTS: In 73% of the cases DNT was lower than the recommended 4 hours. In CAP, a correlation between the CRB-65 and DNT was not found (ρ = 0.13, p = 0.30). Further parameters, e.g. temperature or blood pressure did not improve DNT significantly. Analysis of the CRB-65 score was regularly impeded due to absent documented information on respiratory rate or confusion state. CONCLUSION: In most cases it was feasible to fulfill the 4 hours DNT. The CRB-65 score is an easy bedside tool, which was not routinely assessed by our emergency room personnel but its assessment did not affect DNT in our hospital.
Subject(s)
Community-Acquired Infections/therapy , Emergency Service, Hospital/standards , Hospitals, Teaching , Inpatients , Pneumonia, Bacterial/therapy , Quality of Health Care , Sepsis/therapy , Aged , Feasibility Studies , Female , Follow-Up Studies , Humans , Male , Retrospective Studies , Switzerland , Time FactorsABSTRACT
PRINCIPLES: Hypersplenism can be defined by thrombocytopenia and/or neutropenia resulting from blood cell sequestration in an enlarged spleen. In multimorbid patients the differential diagnosis of cytopenia is challenging and currently there is no established test for diagnosing hypersplenism. METHODS: The epinephrine stimulation test (EST) measures changes in platelets, neutrophil counts and spleen size following a subcutaneous epinephrine injection. We retrospectively analysed the results of EST in 228 patients. RESULTS: Increases in neutrophils and platelets after epinephrine injection were significantly greater in patients with enlarged than in patients with normal size spleens. Using cutoffs of low, intermediate and high confidence EST was positive in 69.8% vs. 41.3% (low confidence), 49.6% vs. 17.4% (intermediate confidence) and 38.8% vs. 10.9% (high confidence) in patients with enlarged vs. normal size spleens. Changes in platelet and neutrophil counts correlated with each other and with changes in spleen size, confirming cell release from the spleen during EST. When stratified according to the underlying diagnosis, patients with liver disease had the strongest response to EST, patients with malignant haematological diseases the weakest. In addition the response to EST was significantly related to changes in platelet and neutrophil counts after splenectomy, confirming the validity of our test. No serious side effects occurred during EST. CONCLUSION: When used in a large patient cohort, EST is a safe and simple diagnostic test. In this exploratory study EST is of value in evaluating patients with cytopenia and a positive EST argues strongly for hypersplenism. Future studies should prospectively evaluate EST for the management of patients with splenomegaly.
Subject(s)
Epinephrine , Hypersplenism/diagnosis , Neutropenia/diagnosis , Spleen/physiopathology , Splenomegaly/diagnosis , Thrombocytopenia/diagnosis , Adolescent , Adult , Aged , Female , Humans , Leukocyte Count , Male , Middle Aged , Platelet Count , Retrospective Studies , Splenectomy , Splenomegaly/surgery , Young AdultABSTRACT
INTRODUCTION: Hepatologists and internists often encounter patients with unexplained high serum ferritin concentration. After exclusion of hereditary hemochromatosis and hemosiderosis, rare disorders like hereditary hyperferritinemia cataract syndrome should be considered in the differential diagnosis. This autosomal dominant syndrome, that typically presents with juvenile bilateral cataracts, was first described in 1995 and has an increasing number of recognized molecular defects within a regulatory region of the L-ferritin gene (FTL). CASE PRESENTATION: Two patients (32 and 49-year-old Caucasian men) from our ambulatory clinic were suspected as having this syndrome and a genetic analysis was performed. In both patients, sequencing of the FTL 5' region showed previously described mutations within the iron responsive element (FTL c.33 C > A and FTL c.32G > C). CONCLUSION: Hereditary hyperferritinemia cataract syndrome should be considered in all patients with unexplained hyperferritinemia without signs of iron overload, particularly those with juvenile bilateral cataracts. Liver biopsy and phlebotomy should be avoided in this disorder.
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Background. The Molecular Adsorbent Recirculating System (MARS) has been shown to clear albumin-bound toxins from patients with liver failure but might cause bleeding complications potentially obscuring survival benefits. We hypothesized that monitoring clotting parameters and bed-side thromboelastography allows to reduce bleeding complications. Methods. Retrospective analysis of 25 MARS sessions during which clotting parameters were monitored by a standardized protocol. Results. During MARS therapy median INR increased significantly from 1.7 to 1.9 platelet count and fibrinogen content decreased significantly from 57 fL(-1) to 42 fL(-1) and 2.1 g/L to 1.5 g/L. Nine relevant complications occurred: the MARS system clotted 6 times 3 times we observed hemorrhages. Absent thrombocytopenia and elevated plasma fibrinogen predicted clotting of the MARS system (ROC 0.94 and 0.82). Fibrinolysis, detected by thromboelastography, uniquely predicted bleeding events. Conclusion. Bed-side thromboelastography and close monitoring of coagulation parameters can predict and, therefore, help prevent bleeding complications during MARS therapy.
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Iron deficiency is known to cause symptoms such as fatigue, depression and restless legs syndrome resulting in impaired quality of life and working capacity. We sought to examine the iron status of reportedly healthy individuals by a framed study design in 58 highly educated Swiss hospital employees and to compare the use of non invasive tests for assessing iron deficiency (ID). A structured interview was used to assess health status, nutritional intake and potential blood loss, blood counts as well as parameters proposed to diagnose iron deficiency were determined. All subjects felt well and were working at their maximum capacity. The male subjects were neither anaemic nor had decreased iron parameters however 50% (23/46) of the women had a serum ferritin of below 22 µg/L, still 33% (15/46) of the women had a ferritin value below the more stringent cut off value of 15 µg/L. In 15% (7/46) of the women we diagnosed iron deficient anaemia. Red meat consumption correlated with ferritin values as did the menstrual blood loss which was estimated by asking the amount of tampons used. Of the additionally analysed iron parameters only the percentage of hypochromic erythrocytes, soluble transferrin receptor and transferrin values were significantly correlated with ferritin and reached an AUCROC of ≥0.7 indicating good predictive tests. Nevertheless neither soluble transferrin receptor nor transferrin showed diagnostic advantages for the diagnosis of ID compared to ferritin alone or together with erythrocyte parameters. Working in a hospital environment and having access to health education does not seem to correlate with prevention of ID or ID anaemia in female hospital employees.
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BACKGROUND: Activated protein C (APC) has been introduced as a therapeutic agent for treatment of patients with severe sepsis due to its unique anticoagulant and anti-inflammatory properties in the vascular system. In this study we investigated novel targets for the anti-inflammatory action of APC in human macrophages. METHODS: Using a genome-wide approach, effects of APC on the expression profile in inflammatory activated human macrophages were analyzed. RESULTS: We identified, for the first time, genes that are specifically regulated by APC under inflammatory conditions, such as chromatin binding protein 4B (CHMP4B) and p300/CBP-associated factor (PCAF), thus indicating a role of APC in the epigenetic control of gene transcription. A functional assay showed the influence of APC in the acetyltransferase/deacetylase activity of nuclear extracts from inflamed macrophages. CONCLUSION: Our data sheds new light on APC targets in inflammation and opens new lines of investigation that may be explored in order to further elucidate its unique molecule properties.
Subject(s)
Gene Expression Profiling , Inflammation/prevention & control , Macrophages/metabolism , Protein C/metabolism , Base Sequence , Blotting, Western , DNA Primers , Humans , Reverse Transcriptase Polymerase Chain ReactionABSTRACT
A 51-year-old man with known pheochromocytoma refused surgical treatment over several years and subsequently presented in catecholamine crisis with shock and multiple organ failure. Laboratory testing revealed liver failure with elevated liver enzymes and coagulation abnormalities, and imaging showed ischemia of extended parts of the right liver lobe. It also revealed a large thrombus in the right portal vein, which together with severe arterial vasoconstriction impaired the dual blood supply of the liver. The patient recovered after effective medical treatment and finally underwent surgical tumor resection. Thereafter, antihypertensive treatment could be stopped. We present this exceptional case of adrenal crisis and discuss the mechanisms leading to liver failure in general and portal vein thrombosis in particular.
Subject(s)
Adrenal Gland Neoplasms/complications , Liver Failure/etiology , Pheochromocytoma/complications , Portal Vein , Venous Thrombosis/etiology , Adrenal Gland Neoplasms/therapy , Humans , Liver Failure/diagnosis , Liver Failure/therapy , Male , Middle Aged , Venous Thrombosis/diagnosis , Venous Thrombosis/therapyABSTRACT
QUESTION: Transient global amnesia (TGA) is characterised by the sudden occurrence of amnesia while lacking other neurological symptoms. Complete remission occurs within 24 hours. The pathogenesis remains unknown. The objective of this study was to evaluate the prevalence of TGA in a primary referral hospital in Uster, Switzerland and examine the accuracy of the diagnostic procedure and outcome. METHODS: We conducted a retrospective review of patients with TGA admitted to the Uster hospital, Switzerland between 1/2005 and 10/2007. Of 8166 patients, 20 consecutive cases fulfilled the diagnostic criteria and were further analysed. We included presenting symptoms, diagnostic tests performed, treatment and outcome. A questionnaire to investigate the treating doctor's knowledge of TGA was conducted. A follow up was conducted in all patients at 19.1 +/- 7.1 months after presentation. RESULTS: The incidence was 6.8/100 000/year. In all patients the symptoms resolved within 24 hours and all patients were seen by a consultant neurologist. Drug related causes were excluded. 25% episodes started after some form of exercise, 20% after emotional distress. All patients underwent cerebral imaging. 76% of the questionnaires sent to in-hospital physicians were returned. Diagnostic criteria of TGA were fully known in 75%. In 30% the diagnosis on admission was not TGA and had to be adjusted during the hospital stay. Follow up showed relapse in 10%. CONCLUSION: TGA is a syndrome of which emergency physicians should be aware. The diagnosis is made clinically and the prognosis is good, although relapses may occur. Missed diagnoses may lead to uncertainty in patients and their relatives.
Subject(s)
Amnesia, Transient Global/epidemiology , Aged , Aged, 80 and over , Amnesia, Transient Global/diagnosis , Clinical Competence , Emergency Service, Hospital , Female , Humans , Incidence , Male , Middle Aged , Retrospective Studies , Switzerland/epidemiologyABSTRACT
Wnt proteins are members of the highly conserved wingless family of proteins responsible for cell differentiation and development and for neoplastic and degenerative processes. Recently, Toll-like receptor-mediated Wnt signaling was found to be associated with innate immunity in Drosophila. Upregulation of Wnt5A in human macrophages upon microbial challenge indicated a similar mechanism. Toll-like receptor-mediated Wnt5A expression is a key process for sustained inflammatory macrophage activation through autocrine and paracrine signaling. Downregulation of Wnt5A expression and subsequent attenuation of inflammatory macrophage responses by activated protein C supports the link between inflammation and coagulation, another highly conserved biologic system. Direct evidence for the relevance of Wnt5A in severe systemic inflammation is provided by the finding of higher Wnt5A levels in patients with sepsis than in healthy individuals. The fact that Wnt5A signaling can be modulated by anti-inflammatory mediators makes this effector molecule an attractive target for therapeutic intervention in inflammatory diseases.
Subject(s)
Gene Expression Regulation , Inflammation/physiopathology , Macrophages/physiology , Toll-Like Receptors/genetics , Wnt Proteins/genetics , Animals , Drosophila Proteins/genetics , Drosophila Proteins/metabolism , Gene Expression , Humans , Protein C/metabolism , Proto-Oncogene Proteins/genetics , Proto-Oncogene Proteins/metabolism , Signal Transduction , Toll-Like Receptors/metabolism , Wnt Proteins/metabolismABSTRACT
OBJECTIVE: Sepsis is a major cause of death for intensive care patients. High concentrations of inflammatory cytokines are characteristic of severe systemic inflammation and activated monocytes are their predominant cellular source. To identify targets for antiinflammatory intervention, we investigated the response of human macrophages to inflammatory and antiinflammatory mediators. METHODS AND RESULTS: We profiled gene expression in human macrophages exposed to lipopolysaccharide (LPS) and interferon (IFN)-gamma in the presence or absence of recombinant activated protein C (APC) or IL-10 and identified Wnt5A as one of the transcripts most highly induced by LPS/IFN-gamma and suppressed by APC and IL-10. We confirmed regulation of Wnt5A protein in macrophages and detected it in sera and bone marrow macrophages of patients with severe sepsis. We established that a functional Wnt5A/frizzled-5/CaMKII signaling pathway was essential for macrophage inflammatory activation. To prove the essential contribution of Wnt5A we measured inflammatory cytokines after stimulation with Wnt5A, silenced Wnt5A by siRNA, and blocked receptor binding with soluble Frizzled-related peptide-1 (sFRP1). CONCLUSIONS: Wnt5A is critically involved in inflammatory macrophage signaling in sepsis and is a target for antiinflammatory mediators like APC or antagonists like sFRP1.
Subject(s)
Calcium-Calmodulin-Dependent Protein Kinase Type 2/metabolism , Interleukin-10/metabolism , Protein C/metabolism , Proto-Oncogene Proteins/metabolism , Signal Transduction/drug effects , Wnt Proteins/metabolism , Calcium-Calmodulin-Dependent Protein Kinase Type 2/genetics , Cell Communication , Cells, Cultured , Gene Expression Profiling , Humans , Inflammation/physiopathology , Inflammation Mediators/analysis , Interferon-gamma/pharmacology , Lipopolysaccharides/pharmacology , Macrophage Activation/drug effects , Macrophages/cytology , Macrophages/drug effects , Phosphorylation , Proto-Oncogene Proteins/genetics , RNA, Messenger/analysis , Sensitivity and Specificity , Sepsis/physiopathology , Signal Transduction/genetics , Wnt Proteins/genetics , Wnt-5a ProteinABSTRACT
BACKGROUND: Numerous, mostly uncontrolled, observations suggest that artificial liver support with the Molecular Adsorbent Recirculating System (MARS) improves pathophysiologic sequelae and outcome of acute and acute-on-chronic liver failure. MARS is felt to be safe, but extracorporeal circuits may activate coagulation. OBJECTIVE: To assess the frequency of and risk factors for activation of coagulation during MARS treatment. PATIENTS/METHODS: Retrospective analysis of coagulopathy/bleeding complications observed during 83 consecutive MARS sessions in 21 patients (11 men; median age 46 years; median three sessions per patient; median duration of session 8 h). RESULTS: Nine clinically relevant episodes of coagulopathy/bleeding were observed in eight patients, forced to premature cessation of MARS in seven and ended lethal in four. Four complications occurred during the first, five during later (third to seventh) MARS sessions and two bleeders tolerated further sessions without complications. Coagulation parameters worsened significantly also during MARS sessions not associated with bleeding (P< or =0.004). In univariate analysis, patient's age, vasopressor therapy, pretreatment INR, fibrin D-dimer and fibrinogen concentrations, but not severity of underlying disease (MELD, Child-Pugh, SAPS II scores), were significantly associated with coagulopathy (P<0.05). Only patient's age, fibrin D-dimer level and INR were retained in a multivariate model correctly classifying 98% of sessions without, but only 33% with complications. CONCLUSION: Coagulation is frequently activated during MARS therapy, potentially leading to bleeding complications and mortality.
Subject(s)
Liver, Artificial/adverse effects , Blood Coagulation , Extracorporeal Circulation/adverse effects , Extracorporeal Circulation/mortality , Female , Hemorrhage , Humans , Incidence , Male , Middle Aged , Multivariate Analysis , Retrospective Studies , Risk Factors , Survival RateABSTRACT
QUESTION UNDER STUDY: To investigate the effectiveness of a single adjusted dose of oral vitamin K to temporarily reverse oral anticoagulation with phenprocoumon (Marcoumar) for heart catheterisation. METHODS: Patients under stable oral anticoagulation with phenprocoumon routinely scheduled for heart catheterizstion were given a single adjusted dose of oral vitamin K a day prior to the intervention. The customary anticoagulation scheme was kept unchanged with the exception of taking the double usual dose of phenprocoumon the evening after the intervention. The primary outcome was the achieved international normalised ratio (INR) immediately before the intervention. Secondary outcomes were the INR after one and four weeks, changes in phenprocoumon and coagulation factors II and VII and adverse events. RESULTS: 38 patients at a median age of 71 (63-74) years scheduled for heart catheterisation were included. The median INR changed from 2.2 (1.9-2.6) the day before to 1.5 (1.4-1.7) immediately before the intervention. An INR < or =1.5 respectively < or =1.8 was achieved in 61% and 95% of the patients. The INR values after one respectively four weeks were comparable to preintervention values. No thromboembolic or bleeding adverse events occurred during the study. CONCLUSION: A single adjusted oral dose of vitamin K given a day prior to heart catheterisation combined with a doubled phenprocoumon dose on the procedure day seems to be an easy applicable, safe and effective way to temporary reverse oral anticoagulation with phenprocoumon.
Subject(s)
Anticoagulants/antagonists & inhibitors , Antifibrinolytic Agents/therapeutic use , Cardiac Catheterization , Phenprocoumon/antagonists & inhibitors , Vitamin K/therapeutic use , Administration, Oral , Aged , Anticoagulants/administration & dosage , Female , Humans , International Normalized Ratio , Male , Middle Aged , Phenprocoumon/administration & dosageABSTRACT
The hemoglobin-haptoglobin (Hb-Hp) scavenger receptor CD163 is a monocyte/macrophage-restricted surface antigen, whose expression is strongly up-regulated by glucocorticoids. We have previously shown that CD163 is expressed by acute myeloid leukemia (AML) cells of monocytic lineage. Herein, we expand this finding by demonstrating constitutive and glucocorticoid-enhanced CD163 expression on French-American-British M4/M5 AML cells, and leukemic blasts of other AML subtypes and normal hematopoietic progenitor cells do not express CD163. We provide evidence that the functional characteristics of CD163 are preserved on malignant cells by showing the capability of types M4/M5 blast cells to internalize Hb-Hp by a CD163-mediated mechanism. Together, our results identify CD163 as a potential target for therapeutic intervention. It is important that CD163 does not appear to be released from leukemic blasts under noninflammatory conditions, thus reducing the probability of off-target side-effects as a result of competitive binding of potential therapeutic ligands to nonmembrane-bound CD163.
Subject(s)
Antigens, CD/biosynthesis , Antigens, CD/immunology , Antigens, Differentiation, Myelomonocytic/biosynthesis , Antigens, Differentiation, Myelomonocytic/immunology , Hematopoietic Stem Cells/immunology , Leukemia, Myeloid/immunology , Monocytes/immunology , Receptors, Cell Surface/biosynthesis , Receptors, Cell Surface/immunology , Acute Disease , Antigens, CD/drug effects , Antigens, Differentiation, Myelomonocytic/drug effects , Cell Line, Tumor , Cell Lineage/immunology , Glucocorticoids/pharmacology , Haptoglobins/immunology , Hemoglobins/immunology , Humans , Receptors, Cell Surface/drug effectsSubject(s)
Glucosephosphate Dehydrogenase/analysis , Glucosephosphate Dehydrogenase/genetics , Point Mutation/genetics , RNA Splice Sites/genetics , Adult , Base Sequence , Glucosephosphate Dehydrogenase/chemistry , Humans , Male , Models, Molecular , Molecular Sequence Data , Protein Structure, Tertiary , SwitzerlandABSTRACT
BACKGROUND: During systemic inflammation, activation of vascular endothelium by proinflammatory cytokines leads to hypotension, microvascular thrombosis, and organ damage. Recent data suggest a link between coagulation and inflammation through the activated protein C (APC) pathway. We studied gene expression profiles in human coronary artery endothelial cells (HCAECs) exposed to proinflammatory stimuli and the influence of APC on expression of candidate genes regulated by these stimuli. METHODS AND RESULTS: HCAECs were stimulated with interleukin-1beta, interferon-gamma, and tumor necrosis factor-alpha. In gene expression profiling, 400 of 8400 genes were regulated >2-fold. Verification of selected candidate genes was achieved by measuring expression of mRNA species by real-time polymerase chain reaction, cytokine secretion by ELISA, and metabolites of tetrahydrobiopterin (BH4) biosynthesis by high-performance liquid chromatography. BH4 synthesis, interleukin-6, interleukin-8, monocyte chemotactic protein-1 (MCP-1), and intercellular adhesion molecule-1 (ICAM-1) were downregulated by APC at the transcriptional and protein level. Endothelial nitric oxide synthase, endothelial adhesion molecule, and vascular cell adhesion molecule-1 were not affected by APC. Activities of transcription factors c-Fos, FosB, and c-Rel were inhibited by APC in inflamed HCAECs. CONCLUSIONS: Our study revealed a novel antiinflammatory mechanism of APC-dependent gene regulation in HCAECs since c-Fos-dependent induction of MCP-1 and ICAM-1 was suppressed. APC downregulates expression and activity of genes related to inflammation, most pronounced under intermediate or mild inflammatory conditions.
Subject(s)
Gene Expression Regulation/drug effects , Protein C/pharmacology , Vasculitis/genetics , Biopterins/analogs & derivatives , Biopterins/biosynthesis , Blood Coagulation Factors/biosynthesis , Blood Coagulation Factors/genetics , Cell Adhesion Molecules/biosynthesis , Cell Adhesion Molecules/genetics , Cells, Cultured/drug effects , Coronary Vessels/cytology , Cytokines/biosynthesis , Cytokines/genetics , Cytokines/metabolism , Gene Expression Profiling , Humans , Interferon-gamma/pharmacology , Interleukin-1/pharmacology , NF-kappa B/biosynthesis , NF-kappa B/genetics , Nitric Oxide Synthase/biosynthesis , Nitric Oxide Synthase/genetics , Nitric Oxide Synthase Type III , Protein C/genetics , Protein C/physiology , RNA, Messenger/biosynthesis , RNA, Messenger/genetics , Receptor, PAR-1/biosynthesis , Receptor, PAR-1/genetics , Receptor, PAR-2/biosynthesis , Receptor, PAR-2/genetics , Receptors, Cell Surface/biosynthesis , Receptors, Cell Surface/genetics , Receptors, Thrombin/biosynthesis , Receptors, Thrombin/genetics , Recombinant Proteins/pharmacology , Transcription Factors/biosynthesis , Transcription Factors/genetics , Transcription, Genetic/drug effects , Tumor Necrosis Factor-alpha/pharmacology , Vasculitis/physiopathologyABSTRACT
BACKGROUND: Previous studies have provided evidence for the importance of platelet-derived nitric oxide (NO) for the regulation of hemostasis. Tetrahydrobiopterin (BH4) is an essential cofactor and regulator of NO synthase activity in the vasculature; however, it is as yet unknown whether platelets dispose over a functional BH4 synthesis. METHODS AND RESULTS: We quantified mRNA expression of genes involved in BH4 synthesis, measured enzymatic activities, and determined intraplatelet levels of pteridines in platelets from healthy volunteers and from patients treated for prolonged periods of time with glucocorticoids. Freshly isolated platelets from healthy volunteers show functional BH4 synthesis, as evidenced by the presence of mRNA species and enzymatic activity of GTP cyclohydrolase I (GTPCH), 6-pyruvoyl tetrahydropterin synthase, and sepiapterin reductase. Biopterin was the major intraplatelet pteridine, whereas no neopterin was found. mRNA expression and enzymatic activity of GTPCH were undetectably low in platelets that had been stored for 5 days, and no pteridines were found in these platelets. Freshly isolated platelets from patients treated with glucocorticoids had decreased mRNA expression and activity of GTPCH compared with platelets from healthy volunteers. CONCLUSIONS: Human platelets dispose over a functional de novo BH4 synthesis. Furthermore, our results indicate the potential of external factors, eg, prolonged storage or glucocorticoid therapy, to significantly affect BH4 synthesis within platelets. Together, these findings offer new insights into the biology and pathobiology of platelet function in humans.