Intracoronary Beta-Radiation Therapy for In-stent Restenosis: Long-Term Success Rate and Prediction of Failure

Objective: The following retrospective observational study assesses the long-term results of intracoronary beta-radiation therapy for patients with in-stent restenosis.
Background: Beta-radiation has been used to treat patients with coronary in-stent restenosis. However, long-term clinical success using this technique has not at this time been established.
Methods: Two-hundred and thirteen consecutive patients received intracoronary brachytherapy (noncentered beta-emitter, Novoste BetaCath™) for in-stent restenosis and were followed up over a period of 39.1 ± 18.4 months. The combined end-point was defined as a major adverse clinical event (MACE) and comprised mortality, acute myocardial infarction, or target vessel revascularization (TVR).
Results: MACE occurred in 110 patients (51.6%): death in 27 patients (12.7%), acute myocardial infarction in 8 patients (3.8%), TVR in 90 patients (42.3%). TVR comprised percutaneous coronary reinterventions in 76 patients (35.7%) and coronary bypass surgery in 24 patients (11.3%). Secondary end-point was determined as target vessel failure and occurred in 93 patients (43.7%). Of note, the frequency of at least two previous target lesion interventions as well as impairment of left ventricular function was associated with reduced success rate, whereas other clinical parameters did not indicate outcome after treatment with intracoronary radiation therapy.
Conclusion: During the mean, a period of 3 years, more than half of the patients receiving intracoronary radiation therapy reached primary end-point, representing, in the main, TVR. During this period a mortality rate of nearly 13% was documented. These results signify a delayed, though continued, restenotic process after index procedure. (J Interven Cardiol 2010;23:60–65)     

1H and 31P NMR spectroscopy of phosphorylated model peptides

The model peptides glycylglycyltyrosylalanine (Gly-Gly-Tyr-Ala), glycylglycylthreonylalanine (Gly-Gly-Thr-Ala) and glycylglycylserylalanine (Gly-Gly-Ser-Ala) were phosphorylated at the hydroxyl groups of their tyrosyl, threonyl and seryl residues, respectively, and characterized by ³¹P and ¹H NMR spectroscopy. The pK_a-value of the phosphoryl group in the tyrosine-containing peptide determined from the pH dependence of chemical shifts is 5.9, the ³¹P chemical shifts at low pH (4.0) and high pH (8.0) are -3.8 and 0.2 ppm, respectively. Phosphorylation also leads to significant shifts of the ¹H NMR resonances of the tyrosine residue; the amide resonance is shifted -0.02 ppm, the Hα resonance 0.06 ppm, the Hβ resonances 0.10 and -0.04 ppm, the H§ resonances 0.02 ppm and the Hω resonances 0.26 ppm. The pK_a-value of the phosphoryl group in the threonine peptide determined from the pH dependence of chemical shifts is 6.1; the ³¹P chemical shifts at low pH (4.0) and high pH (8.0) are -0.1 and 4.8 ppm, respectively. The corresponding values for the serine peptide are 6.1 (pK_a), 0.6 ppm and 4.9 ppm. Phosphorylation also leads to significant shifts of the ¹H NMR resonances of the threonine and serine residues. In the threonine residue the amide resonance is shifted 0.25 ppm, the Hα-resonance -0.43 ppm, the Hβ-resonance 0.03 ppm and the Hγ-resonance 0.09 ppm. In the serine residue the amide resonance is shifted 0.21 ppm, the Hα-resonance -0.17 ppm, and the Hβ-resonances 0.17 ppm.     

Automated synthesis and use of N-chloroacetyl-modified peptides for the preparation of synthetic peptide polymers and peptide-protein immunogens

A method to incorporate N-chloroacetyl moieties at the amino termini of synthetic peptides using a standard program with an automated peptide synthesizer has been developed. The N-chloroacetyl-modified peptides react well with sulfhydryl containing proteins such as 4-mercaptobutyrimide-modified bovine serum albumin to form stable protein-peptide conjugates. By incorporating cysteine into the synthetic peptide, autopolymerization or cyclization of the synthetic peptide occurs by reaction of the free sulfhydryl with the chloroacetyl group. N-Chloroacetyl-derivatized peptides may be useful as reagents for potential peptide immunogens and vaccines.     

Synthesis of novel immunologically active tripalmitoyl-S-glycerylcysteinyl lipopeptides as useful intermediates for immunogen preparations

The synthesis and characterization of lipopeptides consisting of the lipoamino acid N-palmitoyl-S-[2,3-bis(palmitoyloxy)-(2RS)-propyl]-[R]-cysteine (Pam,Cys-OH) and different peptide segments and/or spacer molecules is described. Pam,Cys-peptides, which are derived from the immunologically active TV-terminus of bacterial lipoprotein, were obtained either by solution or solid phase peptide synthesis. In particular, the amphiphilic and water-soluble lipohexapeptides Pam₃Cys-Ser-(Lys)₄ and Pam₃Cys-Ser-(Glu)₄ proved to be potent macrophage and B-cell activators and non-toxic, non-pyrogenic immune adjuvants in combination with or covalently linked to antigens and haptens.     

Cleavage kinetics and anchor linked intermediates in solid phase peptide amide synthesis

Kinetics and cleavage conditions of peptide amide synthesis were studied using the anchor molecules 5-(4′-aminomethyl-3′,5′-dimethoxyphenoxy)valeric acid (4-ADPV-OH) and 5-(2′-aminomethyl-3′,5′-dimethoxyphenoxy)valeric acid (2-ADPV-OH). Unexpectedly the anchor amide alanyl-4-ADPV-NH₂ was isolated and characterized as an intermediate during the cleavage with trifluoroacetic acid (TFA) of alanyl-4-ADPV-alanyl-aminomethyl-polystyrene to yield the alanine amide. As a matter of fact the NH–CH_α bond of the alanyl spacer has to be cleaved to form this intermediate. Using TFA-dichloro-methane (1:9) alanyl-4-ADPV-NH₂ was obtained as a cleavage product in 50% yield within 60min, whereas the isomeric alanyl-2-ADPV-NH₂ was formed more slowly under these mild conditions. At high TFA concentration no difference between the 2- and 4-ADPV anchor was observed in the rate of formation of the free alanine amide. The presence of tryptophan amide in the cleavage mixture resulted in an anchor alkylated tryptophan amide, which remains stable in acidic solution but disappears rapidly in the presence of the resin. A low TFA/high TFA cleavage procedure is recommended for peptide amid synthesis applying the ADPV anchor.     

Maternal alloimmunization against fetal platelet antigens: a prospective study

Summary. Neonatal alloimmune thrombocytopenia (NAIT) is induced by maternal alloantibodies to fetal platelet antigens. This prospective study was carried out to evaluate the incidence of anti-platelet antibodies in 933 mother-child pairs where the mother and child were typed for the human platelet antigens (HPA)-l, -2,-3,-5. Sera from mismatched mother-child pairs were screened for anti-platelet antibodies, anti-HLA class I and blood group ABO IgG antibodies. Platelet-specific antibodies were anti-HPA-3a in one and anti-HP A-5b in 17 neonates, respectively. All these neonates had normal platelet counts. One woman had autoreactive antibodies. Anti-HLA class I and anti-blood group A IgG antibodies were detected in five and four neonates, respectively, born with a platelet count <150×10⁹/l. None of the 11 homozygous HP A-lb mothers became immunized against their heterozygous offspring. The maternal HLA-allotypes HLA-DR52 and -DR6, typically found in individuals immunized against HPA-la and -5b, respectively, were found in three of 11 HPA-b/b non-responders and eight of the anti-HPA-5b responders. The results indicate that a risk for NAIT due to HPA-2 and -3 alloimmunization is low. The HLA allotypes do not predict the risk for NAIT due to HPA-1 or -5 alloimmunization. Maternal anti-HPA-5b antibodies do not correlate with the platelet count in the neonate.     

Hereditary deficiency of phosphoglycerate kinase: a new variant in erythrocytes and leucocytes, not associated with haemolytic anaemia

An X-chromosome linked phosphoglycerate kinase deficiency in erythrocytes and leucocytes was discovered in a large German kindred. Seven males of two generations were found to have only 21% of the normal enzyme activity in their erythrocytes, and twelve females of three generations showed various degrees of this defect. The differences in the expression of the deficiency in heterozygote females are explained by the Lyon hypothesis. The deficiency is caused by a variant enzyme, named phosphoglycerate kinase München. Although it differs from the normal enzyme electrophoretically, the two enzymes resemble one another closely in many respects. They have essentially the same Km for the substrates of the backward reaction, identical pH optima and similar rates of thermal inactivation. In contrast to the nine previously described phosphoglycerate kinase deficiencies, all of which are associated with haemolytic anaemia, the carriers of phosphoglycerate kinase München show no overt clinical symptoms. The erythrocyte concentrations of adenine nucleotides and 2,3-diphosphoglycerate are normal.     

Synthesis of glutathione analogues with modified ionizable groups for the study of enzyme: ligand interactions

The syntheses and analyses of GSSG analogues with modified ionizable groups are described. Using the mixed anhydride method, three symmetrical and three asymmetrical peptide analogues were obtained in moderate overall yields. The products were analyzed by HPLC, ¹H-NMR, thin-layer electrophoresis, and amino acid analysis. They were used to study enzyme: ligand interactions in glutathione reductase.