P3399Influence of TCF21 rs12190287 in the coronary artery disease risk prediction. An association study in a Portuguese population

Aim

Investigate the impact of TCF21 rs12190287 in the prediction and discrimination of CAD risk, individually or into a genetic risk score (GRS) formed by a set of 13 genetic variants.

Methods

We performed a case-control study with 3050 subjects (1619 coronary patients with 53.3±8 years; 78.9% male and 1431 controls with 52.8±8 years; 76.6% male) from GENEMACOR study. We investigated all traditional risk factors (TRF), as well as 13 genetic variants from GWAS with unknown pathophysiological pathway so far, including TCF21 (rs12190287), ZC3HC1 (rs11556924), PSRC1/SORTI (rs599839), PHACTR1 (rs1332844), MIA3 (rs17465637), SMAD3 (rs17228212), ZNF259 (rs964184), ADAMTS7 (rs3825807), CDKN2B (rs4977574), 9p21.3 (rs1333049), KIF6 (rs20455), PCSK9 (rs2114580) and GJA4 (rs618675). A multiplicative genetic risk score with these 13 genetic variants (m13GRS), was calculated. Subsequently, two logistic regressions were performed; primarily with all the TRF and all the genes individually and the second with TRF and m13GRS.

Results

The first multivariate analysis shows that, besides the strong association of the TRF with CAD risk (with smoking status on the top of the list, with an OR of 3.2; p<0.0001), TCF21 rs12190287 was the most significant variant from all the studied genetic set with a CAD risk of 1.5 (95% CI: 1.1–1.9; p=0.004), followed by the well-known genetic determinant CDKN2B rs4977574 (OR=1.4; 95% CI: 1.1–1.7; p<0.002) and ZC3HC1 rs11556924 (OR=1.3; 95% CI: 1.0–1.7; p=0.034). When GRS is included to the model, all the TRF remain in the equation by the same order, and the m13GRS persisted as an independent predictor for CAD risk (OR=1.7; 95% CI: 1.4–2.0; p<0.0001).

Conclusion

TCF21 rs12190287 is a risk factor for CAD in the Portuguese population, either individually or incorporated in a m13GRS. TCF21 risk is independent from TRF. In the future, TCF21 can provide a new clues to identify patients at high cardiovascular risk and become a potential target for gene therapy.

P6196Lipoprotein (a) and cardiovascular risk: are women at increased risk?

Introduction

Coronary artery disease (CAD) is the leading cause of death worldwide, placing a major economic and resource burden on health and public health systems, so efforts are being made to accurately predict risk for major adverse cardiac events (MACE). The field of risk prediction and CAD prevention continues to evolve with the identification of novel risk factors and biomarkers, such as lipoprotein a [Lp)a]. Almost 20% of the population has elevated circulating levels of Lp(a), which is recognized as an independent risk factor for CAD, stroke, peripheral arterial disease, and aortic stenosis. Importantly, studies showed that this was particularly true for women.

Objective

To evaluate if the elevation of Lp(a) is associated with MACE in female, male or both.

Materials and methods

Case control study of 3050 subjects from the GENEMACOR study population. In female population (n=676): cases were 341 patients with at least one >75% coronary stenosis (median age 55.7±7.2) and 335 normal controls (median age 55.8±6) adjusted by age with cases. In male population (n=2374): 1278 patients with at least one >75% coronary stenosis (median age 52.7±8) and 1096 controls (median age 51.9±8) also adjusted by age. χ2 and T student tests were used to analyze the demographic, laboratorial, angiographic and anthropometric characteristics of the population. Lipoprotein (a) was determined by immunoturbidimetry. High Lp(a) level was considered if superior to 30 mg/dl. Logistic regression was used to evaluate Lp(a) as a risk factor for CAD in total, female and male populations.

Results

In female population 44.0% patients vs 21.2% controls (p<0.000) had Lp(a)>30mg/dl. In male population 39.4% patients vs 23.8% controls (p<0.000) had Lp(a)>30mg/dl. In total population Lp(a)>30mg/dl was a predictor for CAD (OR 2.24, 95% CI: 1.91–2.62, p<0.0001). Analyzing by gender, Lp(a)>30mg/dl was also a predictor for CAD either in male (OR 2.08, 95% CI: 1.74–2.5, p<0.0001) or female population (OR 2.92, 95% CI: 2.08–4.09, p<0.0001).

Conclusions

As opposed to other studies, in our population elevated Lp(a) levels (>30mg/dl) were associated with elevated CAD risk, in both men and women. We conclude that Lp(a) can be considered an independent risk factor for CAD disease in our population, and further strategies for Lp(a) reduction may indeed translate in improved outcomes in CAD disease.

P2486The association between genetic variant ZNF259 and decreased kidney function in the diabetic patients

Aim

Investigate whether the reduction of GFR is a direct consequence of T2D or there are other genetic mechanisms involved in the pathophysiology of the evolution to chronic kidney disease.

Methods

Cross-sectional study with a total of 2579 individuals was performed, of which 735 patients had T2D. Subjects were classified as `'diabetic” if they were taking oral anti-diabetic medication or insulin or if their fasting plasma glucose was higher than 7.0 mmol/l or 126 mg/dl. Within the diabetic group, we considered those with (n=63) and without (n=627) decreased GFR. GFR was calculated through the Cockcroft and Gault formula and decreased GFR was defined as GFR<60 ml/min/1.73m2. Twenty-four genetic variants associated with T2D, metabolic syndrome, dyslipidemia and hypertension were investigated for its impact on GFR, namely: MTHFR 677 and 1298; MTHFD1L; PON 55, 192 and 108; ATIR A/C; AGT M235T; ACE I/D; TCF7L2; SLC30A8; MC4R; ADIPOQ; FTO; TAS2R50; HNF4A; IGF2BP2; PPARG; PCSK9; KIF6; ZNF259; LPA; APOE; PSRS1. Risk factors for decreased GFR were also evaluated (essential hypertension, glycaemia >120 mg/ml, dyslipidemia, alcohol consumption, CAD diagnosis). A logistic regression was performed firstly with the risk factors solely; and secondly adding the genetic variants in order to evaluate the independent predictors of progression to renal failure in T2D.

Results

After the first multivariate logistic regression with all the risk factors for decreased GFR, only CAD remained in the equation, showing to be an independent risk factor for progression to renal failure, in T2D (OR=4.17; 95% CI: 1.64–10.59; p=0.003). In the second logistic regression, including risk factors and the genetic variants, only ZNF259 rs964184 showed an independent and significant association with the risk of decreased GFR (OR=3.03; 95% CI: 1.06–8.70; p=0.039).

Conclusion

This study shows that the variant ZNF259 rs964184 is associated with decreased kidney function, independently of other risk factors. This finding needs further investigation to clarify the genetic mechanism behind the association of rs964184 with decreased GFR, in Type 2 diabetes.

P3423The contribution of genetics to premature CAD through different degrees of lifestyle factors: a matter of relative significance?

Introduction

Coronary artery disease (CAD) is a multifactorial process with substantial genetic contribution. However, genetic predisposition among patients with a different number of lifestyle factors and premature CAD, remains a complex and thoroughly unexplored topic.

Objective

To evaluate, in a young population, the importance of conventional risk factors as well as of a genetic risk score in the appearance of CAD.

Methods

A case-control study was conducted with 1075 patients from the GENEMACOR study population, under 50 years-old (555 cases, 86.8% male, mean age 44.1±4.9 years and 520 controls, 86.2% male, mean age 44.3±4.8 years). Univariate analysis addressed the association of different modifiable risk factors with premature CAD. Genetic risk score (GRS) was computed comprising 33 genetic risk variants in a multiplicative method. GRS was evaluated according to the number of traditional risk factors and risk for premature CAD was estimated and its independent predictive value estimated by logistic regression.

Results

72.6% of patients had ≥3 risk factors vs 31.2% of controls (p<0.0001). In comparison with having no risk factors (rf), patients with 1 rf had an OR of 2.79 (1.19–6.53; p=0.015), patients with 2 risk factors had a OR of 6.87 (3.03–15–57, p<0.0001) and patients with 3 modifiable risk factors had a OR of 24.17 (10.87–53.73, p<0.0001) – graph 1. In this young population, mean GRS level was consistently higher among patients with coronary artery disease comparing with a healthy population (0.6±0.6 vs 0.4±0.4, p<0.0001, respectively) – graph 2. GRS in multivariate analysis, proved to be an independent predictor for premature CAD (OR 1.71, CI95% 1.25–2.34, p=0.001).

Conclusion

In our population, GRS was an independent predictor for premature CAD. In young patients with ≥3 risk factors, genetics play a less decisive role in the development of CAD. Even in young patients, modifiable risk factors should be addressed aggressively as they may represent a higher burden than genetic predisposition itself.

P4455The controversial role of genetics behind premature CAD: a plausible excuse for the young?

Introduction

The complex interaction between genes and environmental factors contribute to individual-level risk of coronary artery disease (CAD), often resulting in premature CAD. The role for genetic risk scores in premature CAD is still controversial.

Objective

To evaluate the importance of conventional risk factors and of a genetic risk score in younger and older patients with coronary artery disease

Methods

From a group of 1619 pts with angiographic documented CAD from the GENEMACOR study, we selected 1276 pts admitted for ACS and analysed them in 2 groups (group A: ≤50 years, n=491 pts, 87.2% male, mean age 44±4.9 and group B: >50 years, n=785 pts, 75.2% male, mean age 57±4.2). Univariate analysis was used to characterize the traits of each group and we used ROC curves and respective AUCs to evaluate the power of genetics in the prediction of CAD, through a Genetic Risk Score (GRS).

Results

99.3% of the young patients had at least one modifiable risk factor, 18.4% had 2 modifiable risk factors and 75.2% had 3 or more modifiable risk factors. The pattern of risk factors contributing to CAD were different among groups: family history (A: 27.5%, B: 21.4%, p=0.015) and smoking habits (A: 64.8%, B: 42.9%, p<0.001) were more frequent among patients under 50, and traditional age-linked factors like hypertension (A: 58%, B: 75.7%, p<0.001), diabetes (A: 21.6%, B: 38.6%, p<0.001) were more common in the older group. Acute ST-elevation myocardial infarction was more frequent among the young (A: 55.4%, B: 47.4%, p=0.006), as non-ST clinical presentation was higher among elder patients. Regarding angiographic presentation, single vessel CAD was higher in group A (A: 50.3%, B: 40.9%, p<0.001), while multivessel diasease was higher in group B (A: 33.3%, B: 53.9%, p<0.001). At a mean follow-up of 5 years, older patients had a worst prognosis, registering a higher rate of cardiovascular death (A: 4.1%, B: 8.6%, p=0.002) and higher MACE (A: 26.8%, B: 31%, p=0.128),. Adding the genetic risk score (GRS), we achieved only a slight improvement in the AUC for predicting CAD (0.796->0.805, p=0.0178 and 0.748->0.761, p=0.0007 in patients under and over 50, respectively).

Conclusion

Coronary artery disease is not all the same, as premature CAD shares a unique and specific pattern of risk factors, clinical presentation, angiographic severity and prognosis. Genetics should not be used as an excuse to justify premature CAD, as there is frequently more than one potentially reversible risk factor present even in young patients and the additive predictive value of GRS is modest.

P4459The influence of the polymorphism BUD13-ZNF259 rs964184 on coronary disease according to age

Objective

Investigate the association of BUD13-ZNF259 rs964184 with dyslipidemia and its impact on CAD risk. Evaluate its impact in different age groups of our population.

Methods

A case-control study was performed with 3050 subjects (1619 coronary patients with 53.3±8 years; 78.9% male and 1431 controls with 52.8±8 years; 76.6% male) from the GENEMACOR study population. Traditional risk factors (smoking, dyslipidemia, diabetes, family history, hypertension, body mass index, alcohol consumption, physical inactivity) and others considered new, such as creatinine clearance, pulse wave velocity, homocysteine, fibrinogen, lipoprotein (a), APOB and PCR (hs) were investigated. BUD13-ZNF259 variant was genotyped and analyzed using the dominant model (CG + GG vs. CC). Bivariate and multivariate analyzes (logistic regression) were used to estimate the ORs and 95% CI, after adjusting for potential confounding factors, in 3 different age groups (<45; 45–55; >55).

Results

BUD13-ZNF259 polymorphism presented an independent and significant risk of CAD (OR=1.58; 95% CI: 1.07–2.32; p=0.019) only in the group of young coronary patients <45 years (n=482 patients), as well as dyslipidemia (OR=2.04; 95% CI: 1.26–3.31; p=0.003). After binary logistic regression entering with the interaction between dyslipidemia and the dominant model ZNF259 (CG + GG vs. CC), we verified an association with CAD risk (OR= 1.78; 95% CI: 1.08–2.95; p=0.025).

Conclusion

BUD13-ZNF259 rs964184 variant showed a significant risk for the onset of CAD in the young population (<45 years). The impact of the interaction of ZPR1 protein with tyrosine kinase (Syk) at the cellular level seems to be more relevant in young patients. This aspect may represent a possible prophylactic and therapeutic target, especially in coronary disease in young people.

Abstract 2970: Comparison of anti-CD38 antibodies in vitro mechanisms of action in multiple myeloma

Background: The outcome of multiple myeloma (MM) patients has been dramatically improved by the monoclonal antibody (mAb) daratumumab (DARA). DARA is a human IgG1κ mAb specific for CD38 and approved for the treatment of newly diagnosed and relapsed/refractory MM as a monotherapy and in combination with standard of care. Isatuximab and TAK-079 are additional CD38 targeting mAbs in clinical development by Sanofi and Takeda, respectively. These mAbs are reported to bind different epitopes and induce lysis of MM tumor cells via multiple mechanisms. It is unclear how the pleiotropic mechanisms collectively impact tumor cytolysis and exhibit anti-tumor effects in a comprehensive ex vivo immune milieu.

Methods: For research purposes, DARA was compared with representative mAbs based on the published patent sequences for isatuximab and TAK-079, these surrogate analogs will hereafter be referred to as Sanofi anti-CD38 and Takeda anti-CD38. Mechanism of action (MOA) studies were done to compare antibody dependent cell-mediated cytotoxicity (ADCC), antibody dependent cell phagocytosis (ADCP), complement mediated cytotoxicity (CDC), and early and late detection of apoptosis. In addition, fresh whole blood from healthy donors was used to assess the cumulative effect of the MOAs on MM cell lines.

Results: We tested the CDC activity of the anti-CD38s on multiple MM cell lines with a range of CD38 surface expression and CDC sensitivity levels. In LP-1 and MOLP-8 MM cell lines, DARA resulted in higher levels CDC activity as compared to the other anti-CD38 mAbs. In ADCC and ADCP assays, all 3 anti-CD38 mAbs induced similar levels of MM cell death and phagocytosis. Apoptosis was also assessed in the presence and absence of FcR crosslinking. The Annexin V assay replicated published results that only the Sanofi anti-CD38 was able to induce phosphatidylserine translocation to the cell surface without FcR crosslinking. However, in a robust 5-day cytotoxicity assay detecting metabolically active cells, all 3 antibodies elicited comparable high levels of cell death in the presence of the FcR crosslinker and low levels in its absence. We also performed assays with fresh whole blood from healthy volunteers (n=6) and determined the cumulative effect of the anti-CD38 mAbs on LP-1 and MOLP-8 MM cell lines. DARA demonstrated a higher maximal cytotoxicity than the other mAbs. Moreover, DARA had a significantly lower EC50 than Takeda anti-CD38 in both cell lines and lower than Sanofi-anti-CD38 in MOLP-8.

Conclusion: DARA and surrogate analogs of Sanofi anti-CD38 and Takeda anti-CD38 have similar MOAs with the exception of higher CDC demonstrated by DARA which may contribute to the observed improved efficacy of DARA in a comprehensive immune milieu in vitro. As DARA is the only approved CD38 mAb, it remains to be determined in clinical trials if these in vitro differences lead to differences in clinical benefit.

Citation Format: Michelle Kinder, Mi Ta, Amy Axel, Amy Wong, Stephen Rudnick, Bart de Goeij, Jeroen Lammerts van Bueren, Alex Babich, Mark Mendonca, Jocelyn Sendecki, Christopher Chiu, Kevin Bellew, Colleen Kane. Comparison of anti-CD38 antibodies in vitro mechanisms of action in multiple myeloma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2970.

Poor Antigen Processing of Poxvirus Particles Limits CD4+ T Cell Recognition and Impacts Immunogenicity of the Inactivated Vaccine

CD4⁺ T cells play critical roles in defending against poxviruses, both by potentiating cellular and humoral responses and by directly killing infected cells. Despite this central role, the basis for pox-specific CD4⁺ T cell activation, specifically the origin of the poxvirus-derived peptides (epitopes) that activate CD4⁺ T cells, remains poorly understood. In addition, because the current licensed poxvirus vaccines can cause serious adverse events and even death, elucidating the requirements for MHC class II (MHC-II) processing and presentation of poxviral Ags could be of great use. To address these questions, we explored the CD4⁺ T cell immunogenicity of ectromelia, the causative agent of mousepox. Having identified a large panel of novel epitopes via a screen of algorithm-selected synthetic peptides, we observed that immunization of mice with inactivated poxvirus primes a virtually undetectable CD4⁺ T cell response, even when adjuvanted, and is unable to provide protection against disease after a secondary challenge. We postulated that an important contributor to this outcome is the poor processability of whole virions for MHC-II-restricted presentation. In line with this hypothesis, we observed that whole poxvirions are very inefficiently converted into MHC-II-binding peptides by the APC as compared with subviral material. Thus, stability of the virion structure is a critical consideration in the rational design of a safe alternative to the existing live smallpox vaccine.

International Nosocomial Infection Control Consortium report, data summary of 50 countries for 2010-2015: Device-associated module

BACKGROUND

We report the results of International Nosocomial Infection Control Consortium (INICC) surveillance study from January 2010-December 2015 in 703 intensive care units (ICUs) in Latin America, Europe, Eastern Mediterranean, Southeast Asia, and Western Pacific.

METHODS

During the 6-year study period, using Centers for Disease Control and Prevention National Healthcare Safety Network (CDC-NHSN) definitions for device-associated health care-associated infection (DA-HAI), we collected prospective data from 861,284 patients hospitalized in INICC hospital ICUs for an aggregate of 3,506,562 days.

RESULTS

Although device use in INICC ICUs was similar to that reported from CDC-NHSN ICUs, DA-HAI rates were higher in the INICC ICUs: in the INICC medical-surgical ICUs, the pooled rate of central line-associated bloodstream infection, 4.1 per 1,000 central line-days, was nearly 5-fold higher than the 0.8 per 1,000 central line-days reported from comparable US ICUs, the overall rate of ventilator-associated pneumonia was also higher, 13.1 versus 0.9 per 1,000 ventilator-days, as was the rate of catheter-associated urinary tract infection, 5.07 versus 1.7 per 1,000 catheter-days. From blood cultures samples, frequencies of resistance of Pseudomonas isolates to amikacin (29.87% vs 10%) and to imipenem (44.3% vs 26.1%), and of Klebsiella pneumoniae isolates to ceftazidime (73.2% vs 28.8%) and to imipenem (43.27% vs 12.8%) were also higher in the INICC ICUs compared with CDC-NHSN ICUs.

CONCLUSIONS

Although DA-HAIs in INICC ICU patients continue to be higher than the rates reported in CDC-NSHN ICUs representing the developed world, we have observed a significant trend toward the reduction of DA-HAI rates in INICC ICUs as shown in each international report. It is INICC's main goal to continue facilitating education, training, and basic and cost-effective tools and resources, such as standardized forms and an online platform, to tackle this problem effectively and systematically.

Endogenous antigen processing drives the primary CD4+ T cell response to influenza

By convention, CD4⁺ T lymphocytes recognize foreign and self peptides derived from internalized antigens in combination with MHC class II molecules. Alternative pathways of epitope production have been identified but their contributions to host defense have not been established. We show here in a mouse infection model that the CD4⁺ T cell response to influenza, critical for durable protection from the virus, is driven principally by unconventional processing of antigen synthesized within the infected antigen-presenting cell, not by classical processing of endocytosed virions or material from infected cells. Investigation of the cellular components involved, including the H2-M molecular chaperone, the proteasome, and gamma-interferon inducible lysosomal thiol reductase revealed considerable heterogeneity in the generation of individual epitopes, an arrangement that ensures peptide diversity and broad CD4⁺ T cell engagement. These results could fundamentally revise strategies for rational vaccine design and may lead to key insights into the induction of autoimmune and anti-tumor responses.

Abstract 1294: Identification of tumor-specific antigens associated with RET/PTC3 expression

Relocated in transformation/papillary thyroid carcinoma, RET/PTC3 (RP3) is a fusion oncogene that causes a form of papillary thyroid cancer (PTC). In addition to driving transformation, the constitutively active kinase precociously phosphorylates itself as well as other intracellular proteins, thereby providing tumor-specific targets for the adaptive immune system.

PTCs are known to have the ability to escape the immune system driving a dysregulation of the activity of several cell populations involved in the immune response. Indeed we found that mice immunized with RP3+/MHC class II+ cells produce dramatically fewer IFNg-secreting CD4+ T cells compared to mice immunized with RP3-/MHC class II+ counterparts as measured in the spleens.

We demonstrated the immunogenicity of RP3 with reactivity in both BALB/c and C57BL/6 mice to RP3/IEd- and RP3/CIITA-expressing cells. Also, we observed immunogenicity of RP3-derived phosphopeptides in ELISpot assays, supporting the hypothesis that the aberrant autophosphorylation of RP3 is a source of tumor-specific immunogenicity.

Finally, utilizing a RP3-expressing vaccinia vector for immunization of C57BL/6 mice, we identified peptide sequences that appear to be immunogenic on the basis of unique conformation of the fusion protein that impacts antigen processing.

Taken together these results could pave the way for better vaccine approaches without accompanying autoimmunity.

Citation Format: Laura Sponton, Gabriela Cosma, Mark Mendonca, Mirella Giovarelli, Laurence Crane Eisenlohr. Identification of tumor-specific antigens associated with RET/PTC3 expression. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1294. doi:10.1158/1538-7445.AM2015-1294

Total body irradiation in a patient with fragile X syndrome for acute lymphoblastic leukemia in preparation for stem cell transplantation: A case report and literature review

Fragile X syndrome (FXS) is a congenital disorder caused by expansion of CGG trinucleotide repeat at the 5' end of the fragile X mental retardation gene 1 (FMR1) on the X chromosome that leads to chromosomal instability and diminished serum levels of fragile X mental retardation protein (FMRP). Afflicted individuals often have elongated features, marfanoid habitus, macroorchidism and intellectual impairment. Evolving literature suggests the condition may actually protect from malignancy while chromosomal instability would presumably elevate the risk. Increased sensitivity to ionizing radiation should also be predicted by unstable sites within the DNA. Interestingly, in this report, we detail a patient with FXS diagnosed with acute lymphoblastic leukemia treated with induction followed by subsequent cycles of hyper-CVAD (cyclophosphamide, vincristine, doxorubicin, dexamethasone) with a complete response who then was recommended to undergo peripheral stem cell transplantation. The patient underwent total body irradiation (TBI) as a component of his conditioning regimen and despite the concern of his clinicians, developed minimal acute toxicity and successful engraftment. The pertinent literature regarding irradiation of patients with FXS is also reviewed.

Cytokine analysis by immunoaffinity capillary electrophoresis

Immunoaffinity capillary electrophoresis (ICE) is a powerful tool used to detect and quantify target proteins of interest in complex biological fluids. The target analyte is captured and bound to antibodies immobilized onto the wall of a capillary, labeled in situ with a fluorescent dye, eluted and detected online using laser-induced fluorescence following electrophoretic separation. Here, we illustrate how to construct an immunoaffinity capillary and utilize it to run ICE in order to capture and quantify target cytokines and chemokines from a clinical sample.

[Extracorporeal membrane oxygenation (ECMO) as cardiac assist device in pediatrics]

Extracorporeal membrane oxygenation (ECMO) is a common treatment for severe respiratory failure. However, ECMO can also be used as cardiac support. ECMO is the most common mechanical circulatory assist device in pediatrics, followed by pulsatile ventricular assist devices. Advantages are the simultaneous support of respiratory and hemodynamic functions and the fast bedside availability. The major disadvantage is the limited duration of therapy. The transthoracic connection of ECMO after cardiac failure in cardiothoracic surgery in childhood allows a controlled weaning on the intensive care unit. Weaning from ECMO is successful in about 45 to 80 % in cases of circulatory support; survival rates depend on patient selection, treatment protocol and indication. Bleeding problems, thromboembolic complications, hemolysis, infections, renal and neurologic complications are major problems.

Personal mastery in ethical leadership

The paper briefly explores the manifestation of ethical leadership and examines at length the dimension of character formation. It argues that personal mastery is indispensable to sound character formation because leaders with high personal mastery are more likely to exhibit a disciplined pattern of behavior that is guided by a deep personal vision and enduring moral principles. The paper then discusses some of the sources that the leader can tap to attain personal mastery that leads to the self-transformation of both the leader and of the followers.

Molecular epidemiology of Fonsecaea pedrosoi using mitochondrial DNA analysis

Restriction fragment length polymorphism (RFLP) of mitochondrial DNA (mtDNA) from 49 clinical Fonsecaea pedrosoi isolates (18 isolates from Japan, 17 from Madagascar, 7 from Argentina, 5 from Venezuela, 1 from Costa Rica and 1 unknown) was studied. The 49 isolates were composed of 20 isolates of Type 1, 16 of Type 2, 12 of Type 4 and 1 of a new mtDNA type, Type 7, which was closely related to Type 2. On the bases of the results of 120 isolates of the present (49 isolates) and previous (71 isolates) studies, F. pedrosoi was classified into seven mtDNA types and according to the relationship between mtDNA types and geographic origins: in Japan and probably in China, Type 1 isolates; in Zaire and Madagascar, Type 2; in Central and South America, Type 4 and Type 1. These results indicated that the geographical origin of F. pedrosoi isolate could be roughly inferred from its mtDNA type.

The confirmation and control of metabolic caffeine in standardbred horses after administration of theophylline

The origin of caffeine detections in equine serum and urine after theophylline administrations was examined. Three different preparations containing theophylline were administered to standardbred mares. Both blood and urine samples were collected. Caffeine was detected and quantified in theophylline administration samples by high performance liquid chromatography (HPLC) and liquid chromatography-tandem mass spectrometry (LC-MS-MS). Further in vitro analysis showed that caffeine metabolites were not detected when caffeine, or caffeine-containing products, were added to urine. Data derived from HPLC-UV and LC-MS-MS analysis of dosages of theophylline and caffeine are used to propose the establishment of a threshold limit to control and discern between metabolic and administered caffeine concentrations. A serum caffeine concentration of 250 ng/mL and a urine caffeine concentration of 1000 ng/mL are suggested. Based on the data supplied, these threshold concentrations could effectively control orally administered caffeine in racehorses, up to the dosage used in this work, up to 72 h before sampling time.

Inhibition of constitutive nitric oxide synthase (NOS) by nitric oxide generated by inducible NOS after lipopolysaccharide administration provokes renal dysfunction in rats

Excess NO generation plays a major role in the hypotension and systemic vasodilatation characteristic of sepsis. Yet the kidney response to sepsis is characterized by vasoconstriction resulting in renal dysfunction. We have examined the roles of inducible nitric oxide synthase (iNOS) and endothelial NOS (eNOS) on the renal effects of lipopolysaccharide administration by comparing the effects of specific iNOS inhibition, -N6-(1-iminoethyl)lysine (L-NIL), and 2,4-diamino6-hydroxy-pyrimidine vs. nonspecific NOS inhibitors (nitro- -arginine-methylester). cGMP responses to carbamylcholine (CCh) (stimulated, basal) and sodium nitroprusside in isolated glomeruli were used as indices of eNOS and guanylate cyclase (GC) activity, respectively. LPS significantly decreased blood pressure and GFR (112+/-4 vs. 83+/-4 mmHg; 2.66+/-0.29 vs. 0. 96+/-0.22 ml/min, P < 0.05) and inhibited the cGMP response to CCh. GC activity was reciprocally increased. L-NIL and 2, 4-diamino-6-hydroxy-pyrimidine administration prevented the decrease in GFR (2.71+/-0.28 and 3.16+/-0.18 ml/min, respectively), restored the normal response to CCh, and GC activity was normalized. In vitro application of L-NIL also restored CCh responses in LPS glomeruli. Neuronal NOS inhibitors verified that CCh responses reflected eNOS activity. L-NAME, a nonspecific inhibitor, worsened GFR (0.41+/-0.15 ml/min), a reduction that was functional and not related to glomerular thrombosis, and eliminated the CCh response. No differences were observed in eNOS mRNA expression among the experimental groups. Selective iNOS inhibition prevents reductions in GFR, whereas nonselective inhibition of NOS further decreases GFR. These findings suggest that the decrease in GFR after LPS is due to local inhibition of eNOS by iNOS, possibly via NO autoinhibition.

Agmatine affects glomerular filtration via a nitric oxide synthase-dependent mechanism

Arginine decarboxylase is present in the kidney and metabolizes the amino acid, arginine, to agmatine. Agmatine increases filtration rate in single nephrons (J. J. Lortie, W. F. Novotny, O. W. Peterson, V. Vallon, K. Malvey, M. Mendonca, J. Satriano, P. Insel, S. C. Thomson, and R. C. Blantz. J. Clin. Invest. 97:413-420, 1996). Experiments were conducted to determine whether exogenously administered agmatine exerts these effects via interaction with nitric oxide synthase (NOS) and whether this interaction depends upon alpha 2-adrenergic receptors. Agmatine microperfused (1 microM) into the urinary space of surface glomeruli of the rat increased nephron filtration rate from 33 +/- 4 to 40 +/- 5 nl/min with complete recovery within 10 min. When NG-monomethyl-L-arginine (L-NMMA), a nonselective NOS inhibitor, was systemically infused, agmatine no longer increased single-nephron glomerular filtration rate (SNGFR). BHT-933, an alpha 2-adrenergic agonist, did not increase SNGFR and was unaffected by concurrent L-NMMA. In vitro incubation of freshly harvested glomeruli with agmatine resulted in significant increases in the generation of cGMP, effects similar to carbachol, and blocked by nitro-L-arginine methyl ester (L-NAME) but not yohimbine, an alpha 2-adrenergic antagonist. Agmatine exerts effects on glomerular ultrafiltration via a constitutive NOS-dependent mechanism, and this does not require the participation of alpha 2-adrenoreceptors.

Agmatine, a bioactive metabolite of arginine. Production, degradation, and functional effects in the kidney of the rat

Until recently, conversion of arginine to agmatine by arginine decarboxylase (ADC) was considered important only in plants and bacteria. In the following, we demonstrate ADC activity in the membrane-enriched fraction of brain, liver, and kidney cortex and medulla by radiochemical assay. Diamine oxidase, an enzyme shown here to metabolize agmatine, was localized by immunohistochemistry in kidney glomeruli and other nonrenal cells. Production of labeled agmatine, citrulline, and ornithine from [3H]arginine was demonstrated and endogenous agmatine levels (10(-6)M) in plasma ultrafiltrate and kidney were measured by HPLC. Microperfusion of agmatine into renal interstitium and into the urinary space of surface glomeruli of Wistar-Frömter rats produced reversible increases in nephron filtration rate (SNGFR) and absolute proximal reabsorption (APR). Renal denervation did not alter SNGFR effects but prevented APR changes. Yohimbine (an alpha 2 antagonist) microperfusion into the urinary space produced opposite effects to that of agmatine. Microperfusion of urinary space with BU-224 (microM), a synthetic imidazoline2 (I2) agonist, duplicated agmatine effects on SNGFR but not APR whereas an I1 agonist had no effect. Agmatine effects on SNGFR and APR are not only dissociable but appear to be mediated by different mechanisms. The production and degradation of this biologically active substance derived from arginine constitutes a novel endogenous regulatory system in the kidney.

Strong association between the responder status of the FC gamma II receptor and recurrent spontaneous abortion

Several models exist for the aetiology and therapy of recurrent spontaneous abortion (RSA). They are based in part on the assumption that an increased materno-fetal histocompatibility results in an insufficient maternal immunological recognition of the fetus, and thus renders the maternal immune system unable to sustain the pregnancy. The involvement of the FcgammaII receptor (FcgammaIIR) in RSA was suggested, since FcgammaIIR-blocking antibodies, present in normal pregnancies, could not be found in patients suffering from RSA. The FcgammaIIR is known to be functionally and structurally dimorphic, which results in a responder, respectively non-responder pattern. We used an in vitro proliferation assay to distinguish between FcgammaIIR responder and non-responder phenotypes. In 29 RSA couples we found 97% (28/29) of RSA patients and 100% (29/29) of their partners to be responders, whereas 50 fertile couples and a further 100 unrelated controls revealed distributions of responder vs. non-responder of 73% vs. 27% and 70% vs. 30%, respectively. These differences (RSA vs. controls) are highly significant (P less than or equal to 0.0001). Our results suggest further that the FcgammaIIR dimorphism might be involved in the pathogenesis of RSA.

Monitoring furosemide in racehorses participating in an EIPH program

Analytical procedures were developed to monitor furosemide concentrations in post-race serum and urine samples obtained from horses participating in an exercise-induced pulmonary haemorrhage (EIPH) program. High performance liquid chromatography with ultraviolet light detection proved a reliable, sensitive method for measuring urinary furosemide concentrations up to 12 h after administration of either 150 or 250 mg of the drug to race horses. However, this method was unreliable for determination of serum furosemide concentration. High performance liquid chromatography with fluorescence detection proved a reliable, sensitive method for measuring serum furosemide concentration in horses administered 250 mg of the diuretic, permitting detection of approximately 5-10 ng/ml 6 h after treatment. This method was applied to field conditions where furosemide was administered to horses (between 150 and 250 mg intravenously) 4 h prior to the race. Analytical results assisted in establishing a threshold concentration of 85 ng/ml for serum furosemide. It was found that serum furosemide concentrations are a valid measure of compliance with furosemide administration in the EIPH program.

Determination of procaine in equine plasma and urine by high-performance liquid chromatography

The variability in plasma and urine equine procaine measurement between three independent laboratories using current methods led to the development of a sensitive, reliable, and reproducible high-performance liquid chromatographic method. Standardbred mares were administered either a penicillin G procaine preparation intramuscularly or procaine hydrochloride subcutaneously, and blood and urine were collected at defined time intervals. By HPLC the detection limits for procaine in plasma and urine were 1 and 10 ng/mL, respectively. In contrast procaine in plasma could not be detected by GC-NPD, while the urinary detection limit was 50 ng/mL. The concentration of fluoride in the collection tubes and repetitive freeze-thawing modified plasma procaine measurement. Urinary pH was a factor in estimation of urine procaine levels with greater recovery and reproducibility of results at pH 5 as compared to pH 7. This HPLC method provides a simple, sensitive, and reliable quantitation of procaine in equine plasma and urine.

The influence of furosemide on plasma elimination and urinary excretion of drugs in standardbred horses

A study of the effects of intravenous administration of either 150 mg or 250 mg of furosemide to standardbred mares pre-treated with other drugs was undertaken to determine whether a unique pattern of drug elimination into urine and from plasma for each compound occurred. Furosemide significantly reduced the plasma concentrations of codeine compared to control 2-6 h after furosemide administration. In contrast, the plasma concentrations of theophylline, phenylbutazone, pentazocine, guaifenesin and flunixin were not markedly altered by furosemide. In the case of acepromazine, clenbuterol and fentanyl, the data generated were insufficient to state with certainty whether or not furosemide affected the plasma concentrations of these three drugs. A significant reduction was noted in the urinary concentrations of guaifenesin, acepromazine, clenbuterol, phenylbutazone, flunixin, fentanyl and pentazocine within 1-4 h of furosemide administration. The urinary concentrations of theophylline remained reduced as long as 8 h after furosemide injection. Furosemide administration to horses pre-treated with codeine resulted in depression of urinary morphine concentrations 2-4 h and 9-12 h after furosemide injection. A lower furosemide dose (150 mg) produced changes in drug urinary excretion and plasma elimination equivalent to the higher dose (250 mg). It is evident that furosemide affects the urinary and plasma concentrations of other co-administered drugs but not in a predictable fashion, which limits the extrapolation of these results to as yet untested drugs.

Recovery from potentially lethal damage and recruitment time of noncycling clonogenic cells in 9L confluent monolayers and spheroids

Cells that have been grown as multicell tumor spheroids exhibit radioresistance compared to the same cells grown in monolayers. Comparison of potentially lethal damage (PLD) repair and its kinetics was made between 9L cells grown as spheroids and confluent monolayers. Survival curves of cells plated immediately after irradiation showed the typical radioresistance associated with spheroid culture compared to plateau-phase monolayers. The dose-modification factor for spheroid cell survival is 1.44. Postirradiation incubations in normal phosphate-buffered saline (PBS), conditioned media, or 0.5 M NaCl in PBS reduced the differences in radiosensitivity between the two culture conditions. Postirradiation treatment in PBS or conditioned medium promoted repair of potentially lethal damage, and 0.5 M NaCl prevented the removal of PLD and allowed the fixation of damage resulting in lower survival. Survival of spheroid and monolayer cells after hypertonic NaCl treatment was identical. NaCl treatment reduced Do more than it did the shoulder (Dq) of the survival curve. PLD repair kinetics measured after postirradiation incubation in PBS followed by hypertonic NaCl treatment was the same for spheroids and for plateau-phase monolayers. The kinetics of PLD repair indicates a biphasic phenomenon. There is an initial fast component with a repair half-time of 7.9 min and a slow component with a repair half-time of 56.6 min. Most of the damage (59%) is repaired slowly. Since the repair capacity and kinetics are the same for spheroids and monolayers, the radioresistance of spheroids cannot be explained on this basis. Evidence indicates that the time to return from a Go (noncycling G1 cells) state to a proliferative state (recruitment) for cells from confluent monolayers and from spheroids after dissociation by protease treatment may be the most important determinant of the degree of PLD repair that occurs. Growth curves and flow cytometry cell cycle analysis indicate that spheroid cells have a lag period for reentry into a proliferative state. Since plating efficiency remains high and unchanging during this period, one cannot account for the delay on the basis of the existence of a large fraction of Go cells which are not potentially clonogenic. The cell cycle progression begins in 6-8 h for monolayer cells and in 14-15 h for spheroids. It is hypothesized that the slower reentry of spheroid cells into a cycling phase allows more time for repair than for the rapidly proliferating monolayer cells.

Radioresistance secondary to low pH in human glial cells and Chinese hamster ovary cells

The influence of the extracellular pH on the radiosensitivity of human glial cells and Chinese hamster ovary cells was examined. The period of low pH varied from 0 to 96 hours in glial cells and from 0 to 48 hours in Chinese hamster cells. Maintenance of low pH after a dose of 10 Gy for at least 24 hours for glial cells and at least 6 hours for Chinese hamster cells improved survival by more than one order of magnitude at pH 6.4. Cellular inactivation by irradiation may be impaired by an extracellular pH at or below pH 6.7.