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Introduction: A modified platelet function test (mPFT) was recently found to be superior compared to impedance aggregometry for selection of post-stroke patients with high on-treatment platelet reactivity (HTPR). We aimed to explore some peripheral blood cell characteristics as predictors of recurrent ischemic episodes. The predictive value of mPFT was also assessed in a cohort followed up to 36 months regarding recurrent ischemic vascular events.Methods: As a novelty, not only whole blood (WB), but after 1-h gravity sedimentation the separated upper (UB) and lower half blood (LB) samples were analyzed including neutrophil antisedimentation rate (NAR) in 52 post-stroke patients taking clopidogrel. Area under the curve (AUC, AUCupper and AUClower, respectively) was separately measured by Multiplate in the WB, UB and LB samples to characterize ex vivo platelet aggregation in the presence of ADP. Next, the occurrence of vascular events (stroke, acute coronary syndrome, ACS) were evaluated during 36-month follow-up.Results: A total of 11 vascular events (stroke n = 5, ACS n = 6) occurred during the follow-up period. The AUCupper was significantly higher in patients with recurrent stroke compared to those with uneventful follow-up (p = 0.03). The AUCupper with a cut-off value ≥70 based on the mPFT, was able to predict all stroke events (p = 0.01), while the total vascular events were independently predicted by NAR with a sensitivity of 82% and specificity of 88%.Conclusions: A combination of NAR reflecting the inflammatory state and AUCupper indicating HTPR may provide a better prediction of recurrent ischemic events suggesting a better selection of patients at risk, thus providing an individually tailored vascular therapy.

A growing number of observational studies suggest that high on-clopidogrel platelet reactivity (HPR) is associated with recurrent thrombotic events after percutaneous coronary intervention. We aimed to perform an updated systematic review and meta-analysis on the clinical relevance of HPR to summarize the available evidence and to define more precise effect estimates.Relevant observational studies published between January 2003 and February 2010 were searched that presented intent-to-treat analyses on the clinical relevance of HPR measured with an adenosine diphosphate (ADP)-specific platelet function assay. The main outcome measures were cardiovascular (CV) death, definite/probable stent thrombosis (ST), nonfatal myocardial infarction (MI), and a composite end point of reported ischemic events. The outcome parameters were pooled with the random-effect model via generic inverse variance weighting.Twenty studies comprising a total number of 9,187 patients qualified. High on-clopidogrel platelet reactivity appeared to be a strong predictor of MI, ST, and the composite end point of reported ischemic events (odds ratios [95% CI]: 3.00 [2.26-3.99], 4.14 [2.74-6.25], and 4.95 [3.34-7.34], respectively; P.00001 for all cases). According to the meta-analysis, patients with HPR had a 3.4-fold higher risk for CV death compared with patients with normal ADP reactivity (odds ratio 3.35, 95% CI 2.39-4.70, P.00001). Although there were large differences in the methodology as well as in the definition of HPR between studies, the predicted risk for CV death, MI, or ST was not heterogeneous (I(2): 0%, 0%, and 12%, respectively; P = not significant for all cases).High on-clopidogrel platelet reactivity, measured by an ADP-specific platelet function assay, is a strong predictor of CV death, MI, and ST in patients after percutaneous coronary intervention.

No consensus exists regarding the optimal estimate of light transmission aggregometry (LTA) to reflect P2Y12 ADP receptor inhibition in patients receiving thienopyridine therapy. Currently, the only completely P2Y12-receptor specific method is the measurement of vasodilator stimulated phosphoprotein (VASP) phosphorylation (PRI) with flow cytometry. In the current analysis, we aimed to test the superiority of the late platelet aggregation value over other estimates of light transmission aggregometry in determining P2Y12-receptor inhibition by comparing them to VASP-PRI. On-clopidogrel platelet reactivity was measured in 121 clopidogrel-naïve patients who underwent elective coronary stent implantation. Samples for LTA and VASP assessments were drawn at 12-18 hours after a 600-mg loading dose of clopidogrel and 25 days after the intervention. ADP 5 µM-induced maximal aggregation (AGGmax), 6-minute late aggregation (AGGlate), 6-minute disaggregation (disAGG) and area under the aggregation curve (AUC) were compared to VASP-PRI. Categorical agreement with VASP-defined normal and high platelet reactivity (HPR: PRI ≥ 50%) was calculated according to the optimal cutoff values obtained with receiver-operating characteristic (ROC) curves. The evaluation of 242 measurements showed significant, moderate-strength correlations between VASP-PRI and LTA estimates without the superiority of AGGlate over other estimates (AGGmax: ρ = 0.47; AGGlate: ρ = 0.45; disAGG: ρ = -0.44; AUC: ρ = 0.50). Notably, there were considerable intra-individual differences between VASP and LTA testing. LTA estimates were similar in classifying patients to VASP-defined normal or HPR categories (AGGmax: κ = 0.41; AGGlate: κ = 0.45; disAGG: κ = 0.44; AUC: κ = 0.44). When all estimates of LTA were compared in multivariable models, AUC proved to be the independent linear determinant of VASP-PRI and the best predictor of HPR. Estimates of LTA seem equal in determining the degree of P2Y12-receptor inhibition or in predicting VASP-defined HPR without the superiority of AGGlate over others. These results reject a commonly used hypothesis and might contribute to the standardization of the LTA assay.

Background: Hyperglycemia is a common complication of prematurity, which requires attention because of its high prevalence and multiple consequences. Serum fructosamine used in diabetic patients provides information about the average glucose concentration in the preceding period of 2–3 weeks. Objective: We investigated the physiologic characteristics of a glycemic marker, fructosamine, in preterm and term neonates. We also studied its association with hyperglycemia and related morbidities of preterm infants. Method: Fructosamine levels of 22 extremely premature (gestational age, GA: 25.8 ± 1.0 weeks), 36 moderately premature (GA: 29.8 ± 1.3 weeks) and 26 term infants (GA: 39.1 ± 1.3 weeks) were determined in the 1st week of life. Fructosamine assay was repeated in all preterm neonates in the 4th and 7th postnatal weeks. Hyperglycemic episodes and main morbidities of preterm infants were recorded and analyzed in association with fructosamine levels. Results: Preterm infants had higher fructosamine levels after birth compared to term infants and a postnatal fall was observed. Serum fructosamine did not show association with the occurrence of hyperglycemia or its main morbidities in preterm infants. Conclusion: In the framework of our study, we could not confirm the usefulness of fructosamine determination in the glycemic control of preterm neonates during the perinatal period.

Summary Saccharomyces cerevisiae responds to environ- mental stimuli such as an exposure to pheromone or to hexoses after carbon source limitation with a tran- sient elevation of cytosolic calcium (TECC) response. In this study, we examined whether hexose transport and phosphorylation are necessary for the TECC response. We found that a mutant strain lacking most of the known hexose transporters was unable to carry out the TECC response when exposed to glucose. A mutant strain that lacked the ability to phosphorylate glucose was unable to respond to glucose addition, but displayed a normal TECC response after the addi- tion of galactose. These results indicate that hexose uptake and phosphorylation are required to trigger the hexose-induced TECC response. We also found that the TECC response was significantly smaller than normal when the level of environmental calcium was reduced, and was abolished in a mid1 mutant that lacked a subunit of the high-affinity calcium channel of the yeast plasma membrane. These results indicate that most or all of the TECC response is mediated by an influx of calcium from the extracellu- lar space. Our results indicate that this transient increase in plasma membrane calcium permeability may be linked to the accumulation of Glc-1-P (or a related glucose metabolite) in yeast.

A PMMA (polymethyl-methacrylate)-sorbitol-based capsule system was recently developed, and the permeability of 16 types of capsules with different wall thicknesses and sorbitol contents tested. By optimizing these two parameters, we showed that capsule permeability could be controlled. Promising preliminary data obtained using BPB (Bromophenol Blue) as diffusion marker prompted us to further investigate the antibiotic release of capsules showing the most appropriate release characteristics. PMMA-sorbitol capsules were prepared with wall thickness of 0.5 or 0.6 mm and 60 or 70 w/w% (weight percent) of sorbitol content. In vitro gentamicin, amikacin, tobramycin releases were determined by using a microbiological agar plate diffusion assay. Capsules released 70-100% of their gentamicin load, substantially superior to Septopal, and showed preferable, extended release profiles when compared with the beads. The release kinetics of amikacin and tobramycin closely resembled those of gentamicin. PMMA-sorbitol capsules have been developed and tested, which make them promising devices for local antibiotic delivery.

Az utóbbi években krónikus lymphoid leukaemiában új prognosztikai faktorok vizsgálata került a figyelem középpontjába. A citogenetikai eltérések, az immunglobulin-nehézlánc génmutációs státusza, a CD38- és ZAP70-expresszió mind a közelmúltban megismert prognosztikus faktorok, de kevés az adat a multidrog-rezisztencia jelentőségéről. Célok: A tanulmány célja genetikai, expressziós és funkcionális szinten jellemezni 82 krónikus lymphoid leukaemiában szenvedő beteg multidrog-rezisztenciájának sajátosságait, és vizsgálni azok összefüggését a betegek túlélésével és a kezelésre adott válasszal. Módszerek: a szerzők 66 betegnél vizsgálták az MDR-1 gén ben – Light Cycler Real Time PCR segítségével meghatározott – „Single Nucleotid Polymorphism” sajátosságot, amely irodalmi adatok szerint a P-glikoprotein expresszióját befolyásolja. Összesen 82 betegnél áramlási citometria során anti-P-glikoprotein monoklonális antitest segítségével a P-glikoprotein- expresszió t, az ún. calcein-verapamil teszttel pedig a multidrog-rezisztencia funkcióját vizsgálták. A kezelésre adott választ 35 betegnél vizsgálták, a statisztikai elemzésnél Fischer-tesztet alkalmazva. A túlélési analízist a teljes beteganyagon elvégezték ( n = 82, Log-rank-teszt). Eredmények: Az irodalmi adatokkal ellentétben a szerzők nem találtak korrelációt a vizsgált három multidrogrezisztencia-teszt között. A kezelésre adott választ vizsgálva 35 kezelt betegből 13 nonrespondernek, 22 pedig respondernek bizonyult. A P-glikoprotein-pozitív fenotípusú esetek ( n = 9) 89%-ban klinikailag nonrespondernek bizonyultak (9 P-glikoprotein-pozitív krónikus lymphoid leukaemiás beteg közül 8 nonresponder volt), a P-glikoprotein-negatív esetek ( n = 26) pedig 80%-ban jó terápiás választ mutattak (26 P-glikoprotein-negatív beteg közül 21 responder) ( p < 0,001). Az átlagos várható túlélésben is jelentős, bár nem szignifikáns ( p = 0,106) különbséget észleltek (84 vs 203 hónap). Következtetések: A vizsgált három laboratóriumi paraméter közül a P-glikoprotein sejtfelszíni jelenléte a leginkább releváns adat krónikus lymphoid leukaemiában a kemorezisztencia előjelzésére és a túléléssel kapcsolatban is prognosztikai faktorként értékelhető.

d -Glucose is the preferred carbon and energy source for most eukaryotic cells. Immediately following its uptake, glucose is rapidly phosphorylated to glucose-6-phosphate (Glc-6-P). The yeast Saccharomyces cerevisiae has three enzymes (Hxk1p, Hxk2p, and Glk1p) that convert glucose to Glc-6-P. In the present study, we found that yeast mutants lacking any two of these enzymes retain the ability to efficiently convert glucose to Glc-6-P and thus maintain a low level of cellular glucose. However, a mutant strain lacking all three glucose-phosphorylating enzymes contained up to 225-fold more intracellular glucose than normal. Drugs that inhibit the synthesis or the trimming of the lipid-linked core oligosaccharide Glu 3 Man 9 GlcNac 2 effectively reduced the accumulation of glucose. Similarly, mutations that block the addition of glucose residues to the core oligosaccharide moiety, such as alg5Δ or alg6Δ , also diminished glucose accumulation. These results indicate that the intracellular glucose accumulation observed in the glucose phosphorylation mutant results primarily from the trimming of glucose residues from core oligosaccharide chains within the endoplasmic reticulum (ER). Consistent with this conclusion, both [ 14 C]glucose exchange and subcellular fractionation experiments indicate that much of the accumulated glucose is retained within an intracellular compartment, suggesting that the efficient transport of glucose from the ER to the cytosol in yeast may be coupled to its rephosphorylation to Glc-6-P. The high level of cellular glucose was associated with an increased level of protein glycation and the release of glucose into the culture medium via its transit through the secretory pathway. Finally, we also found that the accumulation of glucose may lead to a subtle alteration in ion homeostasis, particularly Ca 2+ uptake. This suggests that this mutant strain may serve as a useful model to study the consequences of excessive glucose accumulation and protein glycation.

e21140 Background: Multidrug resistance is the most frequent type of resistance to anticancer chemotherapy, which usually results from the overexpression of efflux transporters, such as the MDR1, MRP1 and BCRP. Unfortunatelly, neither the genetic polymorphisms nor the mRNA/protein expression levels correlate closely with the functional activity. On the other hand, although the functional methods separately gave promising results, standardization and reproducibility of these tests failed to conform with values required from routine diagnostic methods. MultiDrugQuant (MDQ) kit was developed as an improved functional assay system, which can measure the multidrug resistance activity of the three, clinically most relevant efflux transporters using flow cytometry in living tumor cells. The present study aimed to carry out the laboratory validation and to evaluate the performance of the MDQ-kit. Methods: Validation of the kit was carried out according to the standards of the Clinical Laboratory Standards Institute in three university centres. Mononuclear cells were separated using Ficoll gradient and tested at 2-5×106/ml within 6 hours after specimen collection. Activities of the multidrug transporters were calculated from the difference between the mean fluorescent intensity of cells w/o the specific inhibitors, respectively. Inaccuracy and comparative measurements were carried out using cell lines with low and high activity of the transporters. Results on different flow cytometers were compared using CD45 CD19 or CD3 monoclonal antibodies for gating the population of interest. Results: The assay proved to be specific and robust at various concentrations of the fluorescent dyes (10-100 % of the original) or inhibitors (50-150 % of the original). Both intraassay and interassay reproducibilities were