AIMSNo studies have yet been conducted concerning plasma N-terminal pro-brain natriuretic peptide (Nt-pro-BNP) levels after Myocardial Infarction (MI) and their relationship with short-term outcomes in diabetic patients.METHODS AND RESULTSFive hundred and sixty patients hospitalized for MI from the RICO survey, including 199 diabetic and 361 non-diabetic subjects, were included in the study. Plasma Nt-pro-BNP levels were measured on admission. Median Nt-pro-BNP levels were significantly higher in diabetic patients compared with non-diabetic patients [245 (81-77) vs. 130 (49-199) pmol/L, P<0.0001]. This difference remained highly significant after adjustment for age, female gender, creatinine clearance, left ventricular ejection fraction (LVEF), plasma peak troponin, anterior wall necrosis, and hypertension. In multivariable analysis, Nt-pro-BNP levels were negatively associated with creatinine clearance (P<0.0001) and LVEF (P<0.0001) and positively associated with plasma peak troponin (P<0.0001), age (P=0.0029), diabetes (P=0.0031), and female gender (P=0.0102). Diabetic patients showed a 4.7-fold increase in hospital mortality (15.6 vs. 3.3%, P<0.0001) and a 2.2-fold increase in cardiogenic shock (17.6 vs. 7.7%, P=0.0004). In multivariable analysis, diabetes was an independent factor for mortality [OR: 1.79 (1.45-2.20); P=0.0064] and cardiogenic shock [OR: 1.45 (1.22-1.72); P=0.0364] when the variable Nt-pro-BNP level was not introduced into the model, but was less significantly associated with mortality [OR: 1.73 (1.39-2.16); P=0.0107] and no longer associated with cardiogenic shock when Nt-pro-BNP was in the model.CONCLUSIONAfter MI, diabetes is independently associated with high plasma Nt-pro-BNP levels. This elevated Nt-pro-BNP is strongly associated with the increased incidence of in-hospital mortality and cardiogenic shock observed in diabetes. Our findings clearly indicate that plasma Nt-pro-BNP provides highly valuable prognostic information on in-hospital outcome after MI, in particular in diabetic patients.

Methods and Results: 101 patients hospitalized for acute non-ST-elevation myocardial infarction (NSTEMI) were included in the study. Median N-terminal fragment of the brain natriuretic peptide (BNP) prohormone (Nt-proBNP) plasma level was 136 (40–335) pmol/l. Patients with increasing levels of troponin I [from low (0.1–10 ng/ml), intermediate (10–40 ng/ml) to high (≧40 ng/ml) levels] had significantly increased levels of Nt-proBNP (p < 0.05). High-risk patients classified by a high PURSUIT score (i.e. supramedian) had significantly increased Nt-proBNP levels compared to patients with low scores (p < 0.001). Moreover, patients with inhospital events (death, recurrent MI or clinical heart failure: 27%) had significantly increased median levels of Nt-proBNP compared to event-free patients (184 vs. 105 pmol/l, p = 0.02). Conclusion: Our data in an unselected population of NSTEMI patients indicate that high levels of circulating Nt-proBNP levels are associated with an increased risk of early cardiovascular events.

Aims: To evaluate the relationship between N-terminal Pro-Brain Natriuretic Peptide (N-BNP) level and contrast-enhanced MRI in patients after acute myocardial infarction (MI). Methods: Eighty-two patients were studied. Venous blood samples were obtained 3 days after MI and MRI was performed from 2 to 7 days after MI, with determination of left ventricular function and acquisition of perfusion data after injection of gadolinium-DTPA. First-pass images (FPI) and Delayed contrast-enhanced (CE) images were analyzed using a 17-segment model, and the extent of transmurality was determined by a visual score. Results: Univariate analysis showed that age (P < 0.001), sex (P < 0.02), Left Ventricular Ejection Fraction (LVEF) <45%(P < 0.002), creatinine (P < 0.05) and delayed CE-MR images (P < 0.006)were predictors of a supramedian N-BNP level. FPI was not a predictor in this univariate analysis (P < 0.078). In a multivariate model, only age, LVEF <45% and delayed CE-MRI were associated with an increased N-BNP level. Conclusion: After MI, high N-BNP levels are dependent on the LVEF but also on the myocardial infarct size derived from the delayed CE-MR images. (C) 2003 European Society of Cardiology. Published by Elsevier B.V. All rights reserved.

To study the recognition by tryptophanyl-tRNA synthetase (TrpRS) of tRNA(Trp) discriminator base, mutations were introduced into the discriminator base of Bacillus subtilis, Archeoglobus fulgidus, and bovine tRNA(Trp), representing the three biological domains. When B. subtilis, A. fulgidus, and human TrpRS were used to acylate these tRNA(Trp), two distinct preference profiles regarding the discriminator base of different tRNA(Trp) substrates were found: G>A>U>C for B. subtilis TrpRS, and A>C>U>G for A. fulgidus and human TrpRS. The preference for G73 in tRNA(Trp) by bacterial TrpRS is much stronger than the modest preferences for A73 by the archaeal and eukaryotic TrpRS. Cross-species reactivities between TrpRS and tRNA(Trp) from the three domains were in accordance with the view that the evolutionary position of archaea is intermediate between those of eukarya and bacteria. NMR spectroscopy revealed that mutation of A73 to G73 in bovine tRNA(Trp) elicited a conformational alteration in the G1-C72 base pair. Mutation of G1-C72 to A1-U72 or disruption of the G1-C72 base pair also caused reduction of Trp-tRNA(Trp) formation. These observations identify a tRNA(Trp) structural region near the end of acceptor stem comprising A73 and G1-C72 as a crucial domain required for effective recognition by human TrpRS.

Ribosomal RNAs undergo several nucleotide modifications including methylation. We identify FtsJ, the first encoded protein of the ftsJ-hflB heat shock operon, as an Escherichia coli methyltransferase of the 23 S rRNA. The methylation reaction requires S-adenosylmethionine as donor of methyl groups, purified FtsJ or a S-150 supernatant from an FtsJ-producing strain, and ribosomes from an FtsJ-deficient strain. In vitro, FtsJ does not efficiently methylate ribosomes purified from a strain producing FtsJ, suggesting that these ribosomes are already methylated in vivo by FtsJ. FtsJ is active on ribosomes and on the 50 S ribosomal subunit, but is inactive on free rRNA suggesting that its natural substrate is ribosomes or a pre-ribosomal ribonucleoprotein particle. We identified the methylated nucleotide as 2'-O-methyluridine 2552, by reverse phase high performance liquid chromatography analysis, boronate affinity chromatography, and hybridization-protection experiments. In view of its newly established function, FtsJ is renamed RrmJ and its encoding gene, rrmJ.

In the majority of eukaryotic tRNAs, the guanosine at position 26 is modified by a dimethyl group, but so far a function of this modification has not been detected. We isolated the Schizosaccharomyces pombe gene, trm1, encoding the tRNA N2,N2-dimethylguanosine-26 methyltransferase. Strains having the gene deleted completely lack N2,N2-dimethylguanosine. In strains carrying the weak ochre tRNA suppressor sup3-i, deletion of trm1 abolishes suppression indicating that the trm1 deletion acts as an antisuppressor mutation. The result suggests that in vivo N2,N2-dimethylguanosine-26 increases the capacity of the sup3-i serine tRNA to translate the UAA (ochre) codon.

5-Methylcytosine (5mC) levels were determined in compositional DNA fractions corresponding to different isochore families from the genomes of Xenopus, chicken, mouse and human, four vertebrates which show different isochore patterns. The results obtained indicate that: (i) positive correlations exist between the 5mC levels and the GC levels of isochores within any given genome; and (ii) DNA from Xenopus isochore families is twice as methylated as DNA from the isochores having the same GC levels from mouse, human and chicken. Moreover, the positive correlations holding between CpG levels and the GC3 levels of coding sequences of warm-blooded vertebrates were shown to comprise two regions with a border at approx. 75% GC3. The correlation corresponding to the higher region (which comprises only very rare high GC3 values in the case of Xenopus) has a higher slope than that corresponding to the lower GC3 values, a phenomenon due in all likelihood, to the increasing contribution of CpG islands. Finally, the observed/expected CpG ratio is higher in Xenopus than in warm-blooded vertebrates.

We have analysed the levels of 5-methylcytosine (5mC) in DNAs from 42 vertebrates, and compiled, including data from literature, a table of genomic 5mC and GC levels (as well as the available c-values, i.e., the haploid genome sizes) of 87 species from all vertebrate classes. An analysis of the data indicates that (i) two positive correlations hold between the 5mC and GC levels of the genomes of fishes/amphibians and mammals/birds, respectively; (ii) the genomes of fishes and amphibians are, on average, about twice as methylated as those of mammals, birds and reptiles, this difference being unrelated to the amounts of repetitive DNA sequences; (iii) the 5mC and CpG observed/expected values show no overlap between the two groups of vertebrates and suggest the existence of two equilibria. The transition separating the two equilibria appears to have taken place at the time of appearance of reptiles. Its possible cause(s) and its implications are discussed.

Venovenous haemofiltration (VVHF) and haemodiafiltration (VVHDF) were performed with a neonatal haemo(dia)filter (Miniflow 10, Hospal) on 8 anaesthetized rabbits infused with branched-chain amino acids (leucine, isoleucine and valine) and alpha-ketoisocaproate. The branched-chain amino acids (BCAA) and alpha-ketoisocaproate blood levels were close to those previously observed in neonates with maple syrup urine disease when extracorporeal blood purification was required. VVHF and VVHDF performances were assessed with two different blood flows (Qb = 8.3 and 16.6 ml/min). VVHDF was performed with four dialysate flow rates (Qd = 0.5, 1.0, 2.0 and 3.0 L/h). Within each period, clearances of the three BCAA were strictly similar. BCAA clearances obtained by VVHF were similar to ultrafiltration rates (respectively, 0.78 +/- 0.14 and 1.79 +/- 0.28 ml/min at high and low Qb; p < 0.05). The alpha-ketoisocaproate clearances obtained by VVHF were 0.39 +/- 0.17 and 0.92 +/- 0.43 ml/min at low and high Qb (not significantly different). Whatever the Qd value, the VVHDF procedures always allowed higher BCAA and alpha-ketoisocaproate clearances as compared with the corresponding VVHF period with similar Qb. BCAA clearances obtained by VVHDF with a 0.5 L/h dialysate flow were 4.1 +/- 0.5 and 5.4 +/- 0.5 mL/min at low and high Qb, respectively. The concurrent alpha-ketoisocaproate clearances were 2.5 +/- 0.8 and 2.9 +/- 1.0 ml/min.

The nucleotide analysis of a cytoplasmic tRNA(Leu) isolated from bovine liver revealed the presence of an unknown modified nucleotide N. The corresponding N nucleoside was isolated by different enzymatic and chromatographic protocols from a partially purified preparation of this tRNA(Leu). Its chemical characterization was determined from its chromatographic properties, UV-absorption spectroscopy and mass spectrometric measurements, as well as from those of the borohydride reduced N nucleoside and its etheno-trimethylsilyl derivative. The structure of N was established as 2'-O-methyl-5-formylcytidine (f5CM), and its reduced derivative as 2'-O-methyl-5-hydroxy-methylcytidine (om5Cm). By sequencing the bovine liver tRNA(Leu), the structure of the anticodon was determined as f5CmAA. In addition, the nucleotide sequence showed two primary structures differing only by the nucleotide 47c which is either uridine or adenosine. The two slightly differing bovine liver tRNAs-Leu(f5CmAA) are the only tRNAs so far sequenced which contain f5Cm. The role of such a modified cytidine at the first position of the anticodon is discussed in terms of decoding properties for the UUG and UUA leucine codons. Recently, precise evidence was obtained for the presence of f5Cm at the same position in tRNAs(Leu)(NAA) isolated from rabbit and lamb liver. Therefore, the 2'-O-methyl-5-formyl modification of cytidine at position 34 could be a general feature of cytoplasmic tRNAs(Leu)(NAA) in mammals.

OBJECTIVE:We compared the ability of peritoneal dialysis, hemofiltration, and continuous hemodiafiltration to remove infused ammonium chloride. STUDY DESIGN:Anesthetized adult rabbits received an intravenous infusion of ammonium chloride. Two methods of removal of ammonium chloride were performed in each animal and compared. In group 1 (n = 6), peritoneal dialysis (dialysate = 75 ml.kg-1) and continuous arteriovenous hemofiltration (CAVH) with a polysulfone 800 cm2 hemofilter (Minifilter Plus; Amicon Division, W. R. Grace & Co., Danvers, Mass.) were simultaneously performed for 40 minutes. In group 2 (n = 6), peritoneal dialysis and continuous arteriovenous hemodiafiltration (CAVHD) (dialysate flow = 1000 ml.hr-1) were simultaneous performed for 40 minutes. In group 3 (n = 6), CAVH and CAVHD were performed successively in random order for 30 minutes each. RESULTS:Animals had high and stable ammonium chloride and glutamine plasma levels during the experimental procedure. No significant difference in ammonium chloride clearance was observed between PD and CAVH (group 1). In comparison with PD or CAVH, CAVHD resulted in significantly higher clearances of ammonium chloride (40% +/- 10% vs 96% +/- 34%, respectively) and of glutamine (195% +/- 17% vs 77% +/- 25%, respectively). CONCLUSION:The overall results indicate that CAVHD should be considered for hyperammonemia when peritoneal dialysis is indicated but unfeasible or inefficient.

BACKGROUND:Continuous hemodiafiltration is potentially more efficient than hemofiltration for removing low molecular metabolites.CASE REPORT:A newborn (2100 g) was admitted suffering from acute distress with statuts epilepticus, liver failure with generalized hyperaminoacidemia, hypoglycemia and oligo-anuria. Peritoneal dialysis, performed on the 17th day of life, was ineffective and the patient was treated by continuous hemofiltration alternating with hemodiafiltration. Clearance of amino-acids was studied for 15 minutes under each technique. The amino-acid concentrations were measured in the infused fluid and in the ultrafiltrate. The baby died on the 20th day despite this treatment.RESULTS:Amino acid clearance by hemodiafiltration was 181 +/- 176% greater than by hemofiltration. The mean improvement for all amino acids was 148%, with extremes of +43% for citrulline and 941% for glutamic acid.CONCLUSION:Continuous hemodiafiltration is an efficient method of removing amino acids; it could be used to treat severe inborn errors of metabolism such as leucinosis.

Biogenesis of cytoplasmic ribosomes universally involves methylation of ribosomal RNA. Little genetic evidence is available about the functional role(s) of this conserved post-transcriptional modification. The only known methylase gene involved in rRNA maturation is ksgA in Escherichia coli, which directs dimethylation of two adjacent adenosines (m62A1518m62A1519) in the loop of a conserved hairpin near the 3′-end of 16 S rRNA. This tandem methylation is the only rRNA modification common to pro and eukaryotes. Disruption of ksgA confers resistance to the aminoglycoside antibiotic kasugamycin without significantly impairing viability. Here we report the cloning of the DIM1 gene encoding the homolog 18 S rRNA dimethylase in Saccharomyces cerevisiae . The yeast enzyme is evolutionary related to the ksgA protein. It carries a distinctive lysine-rich-N-terminal extension with a potential protein kinase C phosphorylation site. Like ksgA, DIM1 belongs to the erm family of prokaryotic 23 S rRNA dimethylases responsible for erythromycin resistance. Surprisingly, disruption of DIM1 turns out to be lethal in yeast.

Background . — Continuous hémodiafiltration is potentially more efficient than hemofiltration for removing low molecular metabolites. Case report — A newborn (2100 g) was admitted suffering from acute distress with statuts epilepticus, liver failure with generalized hyperaminoacidemia, hypoglycemia and oligo-anuria. Peritoneal dialysis, performed on the 17 th day of life, was ineffective and the patient was treated by continuous hemofiltration alterning with hemodiafiltraticn. Clearance of amino-acids was studied for 15 minutes under each technique. The amino-acid concentrations were measured in the infused fluid and in the ultrafiltrate. The baby died on the 20 th day despite this treatment. Results . — Aminoacid clearance by hemodiafiltration was 181 ± 176% greater than by hemofiltration. The mean improvement for all aminoacids was 148%, with extremes of +43% for citrulline and 941% for glutamic acid. Conclusion . — Continuous hemodiafiltration is an efficient method of removing aminoacids; it could be used to treat severe inborn errors of metabolism such as leucinosis.

Biogenesis of cytoplasmic ribosomes universally involves methylation of ribosomal RNA. Little genetic evidence is available about the functional role(s) of this conserved posttranscriptional modification. The only known methylase gene involved in rRNA maturation is ksgA in Escherichia coli, which directs dimethylation of two adjacent adenosines (m6(2)A1518m6(2)A1519) in the loop of a conserved hairpin near the 3'-end of 16 S rRNA. This tandem methylation is the only rRNA modification common to pro and eukaryotes. Disruption of ksgA confers resistance to the aminoglycoside antibiotic kasugamycin without significantly impairing viability. Here we report the cloning of the DIM1 gene encoding the homolog 18 S rRNA dimethylase in Saccharomyces cerevisiae. The yeast enzyme is evolutionary related to the ksgA protein. It carries a distinctive lysine-rich-N-terminal extension with a potential protein kinase C phosphorylation site. Like ksgA, DIM1 belongs to the erm family of prokaryotic 23 S rRNA dimethylases responsible for erythromycin resistance. Surprisingly, disruption of DIM1 turns out to be lethal in yeast.