Cellular pharmacology of multi- and duplex drugs consisting of ethynylcytidine and 5-fluoro-2'-deoxyuridine.

Prodrugs can have the advantage over parent drugs in increased activation and cellular uptake. The multidrug ETC-L-FdUrd and the duplex drug ETC-FdUrd are composed of two different monophosphate-nucleosides, 5-fluoro-2'deoxyuridine (FdUrd) and ethynylcytidine (ETC), coupled via a glycerolipid or phosphodiester, respectively. The aim of the study was to determine cytotoxicity levels and mode of drug cleavage. Moreover, we determined whether a liposomal formulation of ETC-L-FdUrd would improve cytotoxic activity and/or cleavage. Drug effects/cleavage were studied with standard radioactivity assays, HPLC and LC-MS/MS in FM3A/0 mammary cancer cells and their FdUrd resistant variants FM3A/TK(-). ETC-FdUrd was active (IC(50) of 2.2 and 79 nM) in FM3A/0 and TK(-) cells, respectively. ETC-L-FdUrd was less active (IC(50): 7 nM in FM3A/0 vs 4500 nM in FM3A/TK(-)). Although the liposomal formulation was less active than ETC-L-FdUrd in FM3A/0 cells (IC(50):19.3 nM), resistance due to thymidine kinase (TK) deficiency was greatly reduced. The prodrugs inhibited thymidylate synthase (TS) in FM3A/0 cells (80-90%), but to a lower extent in FM3A/TK(-) (10-50%). FdUMP was hardly detected in FM3A/TK(-) cells. Inhibition of the transporters and nucleotidases/phosphatases resulted in a reduction of cytotoxicity of ETC-FdUrd, indicating that this drug was cleaved outside the cells to the monophosphates, which was verified by the presence of FdUrd and ETC in the medium. ETC-L-FdUrd and the liposomal formulation were neither affected by transporter nor nucleotidase/phosphatase inhibition, indicating circumvention of active transporters. In vivo, ETC-FdUrd and ETC-L-FdURd were orally active. ETC nucleotides accumulated in both tumor and liver tissues. These formulations seem to be effective when a lipophilic linker is used combined with a liposomal formulation.

Study of prone positioning to reduce ventilator-associated pneumonia in hypoxaemic patients.

The aim of the present study was to examine whether prone positioning (PP) affects ventilator associated-pneumonia (VAP) and mortality in patients with acute lung injury/adult respiratory distress syndrome. 2,409 prospectively included patients were admitted over 9 yrs (2000-2008) to 12 French intensive care units (ICUs) (OUTCOMEREA). The patients required invasive mechanical ventilation (MV) and had arterial oxygen tension/inspiratory oxygen fraction ratios <300 during the first 48 h. Controls were matched to PP patients on the PP propensity score (+/-10%), MV duration longer than that in PP patients before the first turn prone, and centre. VAP incidence was similar in the PP and control groups (24 versus 13 episodes.1,000 patient-days MV(-1) respectively, p = 0.14). After adjustment, PP did not decrease VAP occurrence (HR 1.64 (95% CI 0.70-3.84); p = 0.25) but significantly delayed hospital mortality (HR 0.56 (95% CI 0.39-0.79); p = 0.001), without decreasing 28-day mortality (37% in both groups). Post hoc analyses indicated that PP did not protect against VAP but, when used for >1 day, might decrease mortality and benefit the sickest patients (Simplified Acute Physiology Score >50). In ICU patients with hypoxaemic acute respiratory failure, PP had no effect on the risk of VAP. PP delayed mortality without decreasing 28-day mortality. PP >1 day might decrease mortality, particularly in the sickest patients.

E-health applications and services for patient empowerment: directions for best practices in The Netherlands.

OBJECTIVE: E-health may enable the empowerment process for patients, particularly the chronically ill. However, e-health is not always designed with the requirements of patient empowerment in mind. Drawing on evidence-based e-health studies, we propose directions for best practices to develop e-health that promotes patient empowerment. METHODS: The concept of patient empowerment in the Dutch setting is discussed first. The prerequisites for patient empowerment are then described and translated into empowerment areas relevant to e-health. MATERIALS: We reviewed Dutch e-health studies that provide insights into what works, and what does not, in e-health. RESULTS: On the basis of the lessons learned from the studies, we propose directions for best practices to develop e-health that promotes patient empowerment. These directions cover various aspects, such as the design and implementation of e-health, its information content and usability, awareness, and acceptance. The studies also indicate the difficulty of establishing that e-health is really dedicated to patient empowerment. CONCLUSIONS: Despite the body of knowledge about patient empowerment, as well as the technological visibility of e-health, evidence for best practices in general and for patient empowerment in particular is scarce. We call for a more systematic evaluation of e-health for patient empowerment and more reliable evidence. Beyond the organizational and technical issues involved in e-health, there is also a need to demonstrate its practical benefits to patients. The Netherlands is active in developing sustainable e-health. National initiatives are now in place to support the processes with the aim of establishing the required evidence-based best practices.

Correlation of CDA, ERCC1, and XPD polymorphisms with response and survival in gemcitabine/cisplatin-treated advanced non-small cell lung cancer patients.

PURPOSE: Selecting patients according to key genetic characteristics may help to tailor chemotherapy and optimize the treatment in non-small cell lung cancer (NSCLC). Polymorphisms at the xeroderma pigmentosum group D (XPD), excision repair cross-complementing 1 (ERCC1), and cytidine deaminase (CDA) genes have been associated with alterations in enzymatic activity and may change sensitivity to the widely used cisplatin-gemcitabine regimen. EXPERIMENTAL DESIGN: Analyses of CDA, XPD, and ERCC1 polymorphisms were done on blood samples of 65 chemotherapy-naïve, advanced NSCLC patients treated with cisplatin-gemcitabine. Furthermore, CDA enzymatic activity was evaluated by high-performance liquid chromatography analysis. Association between XPD Asp(312)Asn and Lys(751)Gln, ERCC1 C118T, and CDA Lys(27)Gln polymorphisms and response, clinical benefit, toxicity, time to progression (TTP), and overall survival (OS) was estimated using Pearson's chi(2) tests, the Kaplan-Meier method, the log-rank test, and the Cox proportional hazards model. RESULTS: The CDA Lys(27)Lys polymorphism significantly correlated with better clinical benefit (P = 0.04) and grade > or =3 neutropenia and thrombocytopenia, as well as with longer TTP and OS (P = 0.006 and P = 0.002, respectively), whereas no significant associations were found among ERCC1 and XPD polymorphisms and both response and clinical outcome. Finally, the enzymatic activity assay showed a significant lower mean in subjects harboring the CDA Lys(27)Lys polymorphism. CONCLUSIONS: Our data suggested the role of CDA Lys(27)Lys polymorphism as a possible predictive marker of activity, toxicity, TTP, and OS in advanced NSCLC patients treated with cisplatin and gemcitabine. These results may be explained by the lower enzymatic activity associated with the Lys(27)Lys CDA and offer a potential new tool for treatment optimization.

Interaction between celecoxib and docetaxel or cisplatin in human cell lines of ovarian cancer and colon cancer is independent of COX-2 expression levels.

Celecoxib, an inhibitor of cyclooxygenase-2 (COX-2), is being investigated for enhancement of chemotherapy efficacy in cancer clinical trials. We determined whether continuous exposure to celecoxib would increase the antiproliferative effects of a 1-h treatment with docetaxel or cisplatin in four human ovarian cancer cell lines. COX-2 protein could not be detected in these cell lines, because of which three COX-2 positive human colon cancer cell lines were included. Multiple drug effect analysis demonstrated additive to borderline antagonistic effects of celecoxib combined with docetaxel. Combination indices with values of 1.4-2.5 in all cancer cell lines indicated antagonism between celecoxib and cisplatin regardless whether celecoxib preceded cisplatin for 3h, was added simultaneously or immediately after cisplatin. Apoptotic features measured in COX-2-negative H134 ovarian cancer cells and COX-2-positive WiDr colon cancer cells, such as the activation of caspase-3 and the number of cells in sub-G0 of the cell cycle, induced by docetaxel were increased in the presence of celecoxib, but were abrogated upon addition of celecoxib to cisplatin. Moreover, the G2/M accumulation in cisplatin-treated cells was less pronounced when celecoxib was present. Drugs did not affect p-Akt. Celecoxib upregulated p-ERK1/2 in H134 cells, but not in WiDr cells. Platinum-DNA adduct formation measured in WiDr cells, however, was reduced when celecoxib was combined with cisplatin. Taken together, our data demonstrate clear antagonistic effects when celecoxib is given concurrently with cisplatin, which is independent of COX-2 expression levels.

Human immunodeficiency virus-associated thrombotic microangiopathies: clinical characteristics and outcome according to ADAMTS13 activity.

Human immunodeficiency virus (HIV) infection is a risk factor for thrombotic microangiopathy (TMA). We sought whether a severe deficiency in ADAMTS13, the enzyme specifically involved in the cleavage of von Willebrand factor, was associated with specific presenting features and outcome in HIV-associated TMA. In this prospective, multicentre, case-control study, 29 patients of 236 in the French Network on TMA had an HIV-associated TMA. Seventeen patients with severe ADAMTS13 deficiency (ADAMTS13 <5% HIV(+) group) were compared to 12 patients with a detectable ADAMTS13 activity (ADAMTS13 >or=5% HIV(+) group). HIV(+) patients were also compared to 62 patients with idiopathic TMA, either with (45 patients, ADAMTS13 <5% idiopathic group) or without (17 patients, ADAMTS13 >or=5% idiopathic group) severe ADAMTS13 deficiency. ADAMTS13 <5% HIV(+) patients had less AIDS-related complications than ADAMTS13 >or=5% HIV(+) patients (23.5% versus 91.6%, respectively, P = 0.0005) and their median CD4(+) T cell count was higher (P = 0.05). TMA-associated death rate was higher in ADAMTS13 >or=5% HIV(+) patients than in ADAMTS13 <5% HIV(+) patients (50% versus 11.7%, respectively, P = 0.04). In ADAMTS13 <5% patients, TMA-associated death rate was comparable between HIV(+) and idiopathic patients (15.5% in idiopathic patients, P-value was non-significant). By contrast, TMA-associated death rate in ADAMTS13 >or=5% HIV(+) patients was higher than in idiopathic patients (11.7% in idiopathic patients, P = 0.04). In conclusion, HIV-associated TMA with severe ADAMTS13 deficiency have less AIDS-related complications and a higher CD4(+) T cell count. TMA prognosis is better and comparable to this of idiopathic forms.

ICU survival and need of renal replacement therapy with respect to AKI duration in critically ill patients.

BACKGROUND: Transient and persistent acute kidney injury (AKI) could share similar physiopathological mechanisms. The objective of our study was to assess prognostic impact of AKI duration on ICU mortality. DESIGN: Retrospective analysis of a prospective database via cause-specific model, with 28-day ICU mortality as primary end point, considering discharge alive as a competing event and taking into account time-dependent nature of renal recovery. Renal recovery was defined as a decrease of at least one KDIGO class compared to the previous day. SETTING: 23 French ICUs. PATIENTS: Patients of a French multicentric observational cohort were included if they suffered from AKI at ICU admission between 1996 and 2015. INTERVENTION: None. RESULTS: A total of 5242 patients were included. Initial severity according to KDIGO creatinine definition was AKI stage 1 for 2458 patients (46.89%), AKI stage 2 for 1181 (22.53%) and AKI stage 3 for 1603 (30.58%). Crude 28-day ICU mortality according to AKI severity was 22.74% (n = 559), 27.69% (n = 327) and 26.26% (n = 421), respectively. Renal recovery was experienced by 3085 patients (58.85%), and its rate was significantly different between AKI severity stages (P < 0.01). Twenty-eight-day ICU mortality was independently lower in patients experiencing renal recovery [CSHR 0.54 (95% CI 0.46-0.63), P < 0.01]. Lastly, RRT requirement was strongly associated with persistent AKI whichever threshold was chosen between day 2 and 7 to delineate transient from persistent AKI. CONCLUSIONS: Short-term renal recovery, according to several definitions, was independently associated with higher mortality and RRT requirement. Moreover, distinction between transient and persistent AKI is consequently a clinically relevant surrogate outcome variable for diagnostic testing in critically ill patients.

Activity and substrate specificity of pyrimidine phosphorylases and their role in fluoropyrimidine sensitivity in colon cancer cell lines.

Thymidine phosphorylase (TP) and uridine phosphorylase (UP) are often upregulated in solid tumors and catalyze the phosphorolysis of natural (deoxy)nucleosides and a wide variety of fluorinated pyrimidine nucleosides. Because the relative contribution of each of the two enzymes to these reactions is still largely unknown, we investigated the substrate specificity of TP and UP in colon cancer cells for the (fluoro)pyrimidine nucleosides thymidine (TdR), uridine (Urd), 5'-deoxy-5-fluorouridine (5'DFUR), and 5FU. Specific inhibitors of TP (TPI) and UP (BAU) were used to determine the contribution of each enzyme in relation to their cytotoxic effect. The high TP expressing Colo320TP1 cells were most sensitive to 5'DFUR and 5FU, with IC50 values of 1.4 and 0.2 microM, respectively, while SW948 and SW1398 were insensitive to 5'DFUR (IC50>150 microM for 5'DFUR). TPI and BAU only moderately affected sensitivity of Colo320, SW948, and SW1398, whereas TPI significantly increased IC(50) for 5'DFUR (50-fold) and 5FU (11-fold) in Colo320TP1 and BAU that in C26A (9-fold for 5'DFUR; p<0.01). In the epithelial skin cell line HaCaT both inhibitors were able to decrease sensitivity to 5'DFUR and 5FU separately. HaCaT might be a model for 5'DFUR toxicity. In the colon cancer cells 5'DFUR degradation varied from 0.4 to 50 nmol 5FU/h/10(6)cells, that of TdR from 0.3 to 103 nmol thymine/h/10(6)cells, that of Urd from 0.8 to 79 nmol uracil/h/10(6)cells, while conversion of 5FU to FUrd was from 0.3 to 46 nmol/h/10(6)cells. SW948 and SW1398 were about equally sensitive to 5'DFUR and 5FU, but SW1398 had higher phosphorylase activity (>65-fold) compared to SW948. In SW948 and HaCaT TPI and BAU inhibited TdR and Urd phosphorolysis (>80%), respectively. Both TP and UP contributed to the phosphorolysis of 5'DFUR and 5FU. In the presence of both inhibitors, still phosphorolysis of 5FU (>40%) was detected in the tumor and HaCaT cell lines, and remarkably, that of all four substrates in SW1398 cells. 5'DFUR phosphorolysis was also measured in situ, where Colo320TP1, SW1398, and HaCaT cells produced significant amounts 5FU from 5'DFUR (>10 nmol/24h/10(6)cells). In Colo320TP1 and in HaCaT cells TPI completely prevented 5FU production, but not in SW1398 cells, where BAU decreased this by 67% (p<0.01). High uracil and dUrd levels were detected in the medium. Uracil accumulation was heavily reduced in the presence of TPI for Colo320TP1 and HaCaT cells, whereas 5FU-induced dUrd production by these cell lines increased (p<0.01). In contrast, for SW1398 cells only BAU was able to reduce uracil levels, and dUrd production remained unchanged. In conclusion, overlapping substrate specificity was found for TP and UP in the cell lines, in which both enzymes were responsible for converting TdR and Urd, and 5'DFUR. 5'DFUR and 5FU were converted to their products in both the colon cancer cells and keratinocytes.

In vivo and in vitro activity and mechanism of action of the multidrug cytarabine-L-glycerylyl-fluorodeoxyuridine.

Multidrugs have the potential to bypass resistance. We investigated the in vitro activity and resistance circumvention of the multidrug cytarabine-L-fluorodeoxyuridine (AraC-L-5FdU), linked via a glycerophospholipid linkage. Cytotoxicity was determined using sensitive (A2780, FM3A/0) and resistant (AG6000, AraC resistant, deoxycytidine kinase deficient; FM3A/TK-, 5FdU resistant, thymidine kinase deficient) cell lines. Circumvention of nucleoside transporter and activating enzymes was determined using specific inhibitors, HPLC analysis and standard radioactivity assays. AraC-L-5FdU was active (IC50: 0.03 microM in both A2780 and FM3A/0), had some activity in AG6000 (IC50: 0.28 microM), but no activity in FM3A/TK(-) (IC50: 18.3 microM). AraC-nucleotides were not detected in AG6000. 5FdU-nucleotides were detected in all cell lines. AraC-L-5FdU did not inhibit TS in FM3A/TK(-) (5%). Since phosphatase/nucleotidase-inhibition reduced cytotoxicity 7-70-fold, cleavage seems to be outside the cell, presumably to nucleotides, and then to nucleosides. The multidrug was orally active in the HT-29 colon carcinoma xenografts which are resistant toward the single drugs.

Innovating eHealth in the Netherlands.

Innovation is essential to improve accessibility, effectiveness and efficiency of healthcare delivery. eHealth promises these improvements provided that it complies to essential requirements with respect to quality and patient safety. eHealth must be implemented thoughtfully to yield full benefit to the patient. However, there exists no structured framework of essential requirements to guide development, implementation and usage. The scope of application of eHealth is wide and new technology is introduced continuously. So, the framework of essential requirements must evolve as well to support and encourage innovation. The author proposes a process for continuous verification and validation of eHealth throughout development, implementation and use and a method to continuously update the framework of essential requirements.

Gallstone formation after weight loss following gastric banding in morbidly obese Dutch patients.

BACKGROUND: Obesity is a risk factor for the development of gallstones. Rapid weight loss may be an even stronger risk factor. We retrospectively assessed the prevalence and risk factors of gallstone formation after adjustable gastric banding (AGB) in a Dutch population. METHODS: All patients who underwent AGB between Jan 1992 and Dec 2000 for morbid obesity were invited to take part in this study. Transabdominal ultrasonography of the gallbladder was performed in those patients without a prior history of cholecystectomy (Group A). Additionally, 45 morbidly obese patients underwent ultrasonography of the gallbladder before weight reduction surgery (Group B). RESULTS: 120 patients were enrolled in the study (Group A). Prior history of cholecystectomy was present in 21 patients: 16 before and 5 after AGB. Ultrasonography was performed in 98 patients: gallstones were present in 26 (26.5%). On multivariate analysis, neither preoperative weight, nor maximum weight loss, nor the interval between operation and the postoperative ultrasonography were determinants of the risk for developing gallstone disease. Prevalence of gallstones was significantly lower in the morbidly obese patients who had not yet undergone weight reduction surgery (Group B). CONCLUSIONS: Rapid weight loss induced by AGB, is an important risk factor for the development of gallstones. No additional determinants were found. Every morbidly obese patient undergoing bariatric surgery must be considered at risk for developing gallstone disease.

Reprogramming of circulatory cells in sepsis and SIRS.

Immune status is altered in patients with sepsis or non-infectious systemic inflammatory response syndrome (SIRS). Reduced ex-vivo TNF production by endotoxin-activated monocytes has been regularly reported. This observation is reminiscent of the phenomenon of endotoxin tolerance, and the term 'leukocyte reprogramming' well defines this phenomenon. This review will outline that the hyporesponsiveness of circulating leukocytes is not a generalized phenomenon in sepsis and SIRS. Indeed, the nature of the insult (i.e. infectious versus non-infectious SIRS; under anesthesia [surgery] or not [trauma, burn]), the nature of the activator used to trigger leukocytes (i.e. different Toll-like receptor ligands or whole bacteria), the nature of the cell culture (i.e. isolated monocytes versus peripheral blood mononuclear cells versus whole blood assays), and the nature of the analyzed cytokines (e.g. IL-1beta versus IL-1ra; TNF versus IL-10) have a profound influence on the outcome of the response.

Localizing antithrombotic and vasodilatory activity with a novel, ultrafast nitric oxide donor.

Reaction of nitric oxide (NO) with L-proline in methanolic sodium methoxide yields a diazeniumdiolate product, C5H7N3O4Na2.CH3OH (PROLI/NO), that can be stabilized in basic solution but that dissociates to proline (1 mol) and NO (2 mol) with a half-life of only 1.8 s at pH 7.4 and 37 degrees C. This kinetic behavior has allowed the generation of highly localized antiplatelet and vasodilatory effects. By infusing solutions containing 4 microM PROLI/NO in 0.1 M sodium hydroxide at the rate of 1 nmol.min-1 immediately upstream from a polyester vascular graft in the unheparinized baboon circulatory system, for example, platelet deposition at the normally thrombogenic graft surface was substantially reduced relative to controls receiving only 0.1 M sodium hydroxide. In a second study, infusion of PROLI/NO into the right atrium of sheep with induced pulmonary hypertension selectively dilalated the lung vasculature, dose-dependently reducing the pulmonary arterial pressure by as much as 9 mmHg with no observable effect on the systemic arterial pressure at an infusion rate of up to 24 nmol.kg-1.min-1. PROLI/NO could also be formulated as an insoluble polymer blend that released NO smoothly for prolonged periods. The results suggest that localized delivery of diazeniumdiolates such as PROLI/NO which generate NO with extreme rapidity on entering the blood stream may hold considerable promise for inhibition of thrombus formation, selective dilation of the vasculature, and other research and clinical applications.

Folate concentration dependent transport activity of the Multidrug Resistance Protein 1 (ABCC1).

The Multidrug Resistance Protein MRP1 (ABCC1) can confer resistance to a variety of therapeutic drugs. In addition, MRP1/ABCC1 mediates cellular export of natural folates, such as folic acid and l-leucovorin. In this study we determined whether cellular folate status affected the functional activity of MRP1/ABCC1 mediated efflux of an established substrate, the anthracycline daunorubicin (DNR). As a model system we used the human ovarian carcinoma cell line 2008wt, and its MRP1/ABCC1 transfected subline 2008/MRP1. Both types of these moderate- and high-MRP1/ABCC1 expressing cells displayed efflux of DNR when maintained in standard culture media (2.3microM folic acid). The initial total cellular DNR efflux rate in 2008/MRP1 cells was approximately 2-fold higher compared to 2008wt cells. This efflux consisted of MRP1/ABCC1 mediated transport, possibly non-MRP1 mediated transport, as well as passive diffusion. Benzbromarone, a specific MRP1 inhibitor, decreased the initial efflux rate in 2008/MRP1 cells (4-fold) and in 2008wt cells (2-fold). When 2008/MRP1 cells were challenged for 2 days in folate-free medium, total cellular DNR efflux was decreased to 43% of the initial efflux rate under folate-rich conditions. In 2008wt cells DNR efflux was decreased to 84% of the folate-rich conditions. Benzbromarone did not inhibit DNR efflux after the folate-free period in both cell lines. Repletion of folate by a 2-24hr exposure to 2.5microM l-leucovorin or folic acid resulted in a complete restoration of DNR efflux. In contrast, expression of MRP1/ABCC1 protein was not changed significantly during the folate-free period or the repletion-period, nor were cellular ATP or ADP pools. In conclusion, this study demonstrates that the cellular folate status can influence the transport activity of MRP1/ABCC1. These results have potentially important implications in the understanding of the (patho-)physiological roles of MRP1/ABCC1, and possibly other ABC transporter proteins in cellular folate homeostasis and drug resistance.

Predictors of short-term mortality in critically ill patients with solid malignancies.

UNLABELLED: Admission of cancer patients with serious medical complications to the ICU remains controversial primarily because of the high short-term mortality rates in these patients. However, the cancer patient population is heterogeneous regarding age, underlying conditions, and curability of their disease, suggesting that large variations may occur in the effectiveness of intensive care within this subgroup of critically ill patients. OBJECTIVES: To identify factors predicting 30-day mortality in patients with solid tumors admitted to a medical ICU. PATIENTS AND METHODS: We conducted a retrospective study in 120 consecutive cancer patients (excluding patients with hematological malignancies) admitted to the medical ICU of a 650-bed university hospital between January 1990 and July 1997. Medical history, physical and laboratory test findings at admission, and therapeutic interventions within the first 24 h in the ICU were recorded. The study endpoint was vital status 30 days after ICU admission. Stepwise logistic regression was used to identify independent prognostic factors. RESULTS: The observed 30-day mortality rate was 58.7 % (n = 68), with most deaths (92 %) occurring in the ICU. Univariate predictors of 30-day mortality were either protective [prior surgery for the cancer (p = 0.01) and complete remission (p = 0.01)] or associated with higher mortality [Knaus scale C or D (p = 0.02), shock (p = 0.04), need for vasopressors (p = 0.0006) or for mechanical ventilation (p = 0.0001), SAPS II score greater than 36 (p = 0.0001), LOD score greater than 6 (p = 0.0001), and ODIN score > 2 (p = 0.0001)]. Three variables were independent predictors: previous surgery for the cancer (OR 0.20, 95 % CI 0.07-0.58), LOD score > 6 (OR 1.26, 95 % CI 1.09-1.44), and need for mechanical ventilation (OR 3.55, 95 % CI; 1.26-6.7). Variables previously thought to be indicative of a poor prognosis (i. e., advanced age, metastatic or progressive disease, neutropenia or bone marrow transplantation) were not predictive of outcome. CONCLUSION: When transfer to an ICU is considered an option by patients and physicians, 30-day mortality is better estimated by an evaluation of acute organ dysfunction than by the characteristics of the underlying malignancy.

Differing roles of nitric oxide in the pathogenesis of acute edematous versus necrotizing pancreatitis.

BACKGROUND: Microcirculatory changes and leukocyte-endothelial interaction are both central to the pathogenesis of acute pancreatitis. We studied the effects of nitric oxide (NO) donors (intravenous or inhaled) and NO inhibitors, which affect each of these processes, on markers of experimental mild (edematous) and severe (necrotizing) pancreatitis in rats. METHODS: Mild pancreatitis was induced with intravenous cerulein (n = 100) and severe pancreatitis with intravenous cerulein and intraductal glycodeoxycholic acid (n = 100). Each group was randomly divided into five equal treatment subgroups: control, NO-synthase substrate L-arginine, NO donor sodium nitroprusside, NO-synthase inhibitor N-nitro-L-arginine methyl ester (L-NAME), and NO-inhalation. After 6 hours edema was measured by a wet/dry weight ratio, and pancreatic injury was quantified by tissue levels of trypsinogen activation peptides (TAPs) and by histologic analysis of inflammation and necrosis. RESULTS: In mild pancreatitis (1) both NO donors reduced edema formation (p < 0.001) and also reduced intrapancreatic TAPs (p < 0.03); (2) L-NAME significantly increased tissue TAPs (p < 0.03); and (3) inhaled NO had no effect. In severe pancreatitis (1) both intravenous NO donors reduced edema formation (p < 0.005) and both markedly reduced intrapancreatic TAPs (p < 0.001); (2) L-NAME did not further increase the already high tissue TAPs; and (3) inhaled NO decreased tissue TAPs (p = 0.01). Evaluation of inflammation and necrosis by histologic scoring confirmed the reduction of pancreatic injury by NO donors and worsening with NO-synthase inhibitor. CONCLUSIONS: NO donors have a beneficial effect on edema formation in acute pancreatitis but confer more important protection against ectopic trypsinogen activation, which correlates with mortality, inflammation, and necrosis. Although direct microcirculatory action is likely, the salutary effect of inhaled NO in severe pancreatitis may suggest indirect action on circulating leukocytes, which are thought to potentiate tissue injury.

Prolonged pulmonary vasodilator action of inhaled nitric oxide by Zaprinast in awake lambs.

Inhaled nitric oxide (NO) has been shown to selectively dilate the pulmonary vasculature. Zaprinast, an inhibitor of guanosine 3',5'-cyclic monophosphate-specific phosphodiesterase, augments smooth muscle relaxation induced by endothelium-dependent vasodilators. The present study was designed to determine whether intravenous administration of Zaprinast potentiates the vasodilating effects or prolongs the duration of action of intermittent NO inhalation. Eight awake lambs with U-46619-induced pulmonary hypertension breathed three concentrations of NO (5, 10, and 20 ppm) in a random order before and during an intravenous Zaprinast infusion (0.1 mg.kg-1.min-1). Inhaled NO decreased pulmonary arterial pressure (PAP) in a dose-dependent fashion, with mean PAP reduction at 5, 10, and 20 ppm NO inhalation of 6 +/- 1, 7 +/- 1, and 9 +/- 1 (SE) mmHg, respectively. Although the Zaprinast infusion did not change the magnitude of mean PAP reduction, it caused a statistically significant reduction of pulmonary vascular resistance and prolonged the duration of action of inhaled NO (half-times of vasodilator response to 5, 10, and 20 ppm NO inhalation: 1.9 +/- 0.1, 2.1 +/- 0.2, and 2.1 +/- 0.2 min, respectively; half-times of NO inhalation with Zaprinast: 9.7 +/- 1.7, 11.5 +/- 2.2, and 12.3 +/- 2.0, respectively). Plasma concentrations as well as the transpulmonary differences of guanosine 3',5'-cyclic monophosphate were increased by the Zaprinast infusion during NO inhalation. A stable level of pulmonary vasodilation was demonstrated in four additional lambs by combining intermittent NO breathing with an intravenous infusion of Zaprinast.

Pulmonary vasodilation by nitric oxide gas and prodrug aerosols in acute pulmonary hypertension.

Sodium 1-(N,N-diethylamino)diazen-1-ium-1,2-diolate (DEA/NO; Et2N-[N(O)NO]Na) is a compound that spontaneously generates nitric oxide (NO). Because of its short half-life (2.1 min), we hypothesized that inhaling DEA/NO aerosol would selectively dilate the pulmonary circulation without decreasing systemic arterial pressure. We compared the pulmonary selectivity of this new NO donor with two other reference drugs: inhaled NO and inhaled sodium nitroprusside (SNP). In seven awake sheep with pulmonary hypertension induced by the infusion of U-46619, we compared the hemodynamic effects of DEA/NO with those of incremental doses of inhaled NO gas. In seven additional awake sheep, we examined the hemodynamic effects of incremental doses of inhaled nitroprusside (i.e., SNP). Inhaled NO gas selectively dilated the pulmonary vasculature. Inhaled DEA/NO produced nonselective vasodilation; both systemic vascular resistance (SVR) and pulmonary vascular resistance (PVR) were reduced. Inhaled SNP selectively dilated the pulmonary circulation at low concentrations (< or = 10(-2)M), inducing a decrease of PVR of up to 42% without any significant decrease of SVR(-5%), but nonselectively dilated the systemic circulation at larger doses (> 10(-2)M). In conclusion, despite its short half-life, DEA/NO is not a selective pulmonary vasodilator compared with inhaled NO. Inhaled SNP appears to be selective to the pulmonary circulation at low doses but not at higher levels.

Indium-111 antimyosin scintigraphy before and after coronary bypass surgery: unexpected preoperative myocardial uptakes.

The present study was designed to evaluate 111In-antimyosin scintigraphy in detecting pre- and post-operative myocardial infarction in patients undergoing coronary artery bypass surgery. Fab antimyosin scintigraphy has been shown to be sensitive and specific in detecting myocardial necrosis and to be potentially valuable in situations where other criteria are not reliable. In a previous study, postoperative antimyosin uptakes occurred in 82% of the studied patients. Sixteen consecutive patients with an indication of coronary artery surgery were assessed by preoperative coronary angiography, serial electrocardiograms, and myocardial scanning with 111Indium-labeled antimyosin antibodies performed before and after operation. In four patients, a recent myocardial infarction (1 to 3 months) was detected with an accurate localization when compared to the classic criteria of myocardial infarction. One more patient with a 21-year old myocardial infarction showed an intense uptake whereas there was no recent acute coronary event. Four other patients had an unexpected preoperative uptake, since there were no acute coronary events in their medical history. All preoperative scintigraphic uptakes were still present on the second scan performed postoperatively in these nine patients. Only one patient showed a new postoperative uptake when compared to the preoperative scan which was normal; this postoperative septal infarct was confirmed by a postoperative coronary angiography. Extracardiac uptakes (sternum and ribs) were frequently observed after operation and might hamper the interpretation of postoperative scintigrams. Unexpected preoperative uptakes may be related to non diagnosed small necrosis. A preoperative reference scan is required for an accurate interpretation of a postoperative 111In-antimyosin uptake. Moreover, extracardiac uptakes may limit the interpretation of perioperative cardiac damage.

[Antiplatelet properties of nitrogen monoxide]. / Propriétés antiplaquettaires du monoxyde d'azote.

Nitric (correction of nitrous) oxide (NO) plays a fundamental part in the haemostatic equilibrium between the endothelium and platelets, an equilibrium of established clinical importance in cardiovascular disease. NO stimulates the enzyme guanylate cyclase which is responsible for synthesis of GMPc, the increase of which results in platelet inhibition. Synthesis of NO may have endogenous auto or paracrine origine from platelets or endothelial cells and participates in the local regulation of platelet function in association with other products of endothelial or platelet synthesis. Exogenous administration is common in therapeutics either in molecules which release NO (nitrate derivatives, sodium nitropruside, molsidomine, etc) or by NO gas administered by inhalation. The antiplatelet effect of NO has been clearly demonstrated in vitro, in vivo or ex vivo, in animals and humans, and probably explains, at least partially, the efficacy of nitrate derivatives in ischaemic coronary artery disease. Nevertheless, the platelet inhibition observed with intravenous NO releasing drugs is associated with potentially harmful systemic hypotension. Platelet inhibition by inhalation of NO could be an alternative means of avoiding this unwanted effect.