Rapid synthesis of maleimide functionalized fluorine‐18 labeled prosthetic group using “radio‐fluorination on the Sep‐Pak” method

Following our recently published fluorine‐18 labeling method, “Radio‐fluorination on the Sep‐Pak”, we have successfully synthesized 6‐[¹⁸F]fluoronicotinaldehyde by passing a solution (1:4 acetonitrile: t‐butanol) of its quaternary ammonium salt precursor, 6‐(N,N,N‐trimethylamino)nicotinaldehyde trifluoromethanesulfonate ( 2 ), through a fluorine‐18 containing anion exchange cartridge (PS‐HCO₃). Over 80% radiochemical conversion was observed using 10 mg of precursor within 1 minute. The [¹⁸F]fluoronicotinaldehyde ([¹⁸F] 5 ) was then conjugated with 1‐(6‐(aminooxy)hexyl)‐1H‐pyrrole‐2,5‐dione to prepare the fluorine‐18 labeled maleimide functionalized prosthetic group, 6‐[¹⁸F]fluoronicotinaldehyde O‐(6‐(2,5‐dioxo‐2,5‐dihydro‐1H‐pyrrol‐1‐yl)hexyl) oxime, 6‐[¹⁸F]FPyMHO ([¹⁸F] 6 ). The current Sep‐Pak method not only improves the overall radiochemical yield (50 ± 9%, decay‐corrected, n = 9) but also significantly reduces the synthesis time (from 60‐90 minutes to 30 minutes) when compared with literature methods for the synthesis of similar prosthetic groups.     

Twenty years experience of surgical aortic valvotomy for critical aortic stenosis in early infancy.

OBJECTIVE: To examine early and long-term results of surgical aortic valvotomy in neonates and infants aged less than 3 months. METHODS: A review of all 34 neonates (n=26) and young infants (n=8) aged 1-62 days undergoing primary open valvotomy for aortic valve stenosis between 1983 and 2003 was carried out. Associated major cardiac anomalies were endocardial fibroelastasis (n=8), aortic coarctation (n=3), subvalvular aortic stenosis (n=2), and ventricular septal defect (n=1). Risk factors for early mortality were estimated. Current information was available for 31 patients for a follow-up of 115+/-67 months. Kaplan-Meier method was used to estimate freedom from reintervention. RESULTS: Two neonates died early: operative mortality of 6% (2/34). Risk factors for early mortality were associated endocardial fibroelastosis, monocuspid aortic valve and impaired left ventricular function. No patient died late. Seven patients needed reintervention for re-aortic stenosis (n=5) or aortic insufficiency (n=2), i.e., re-valvotomy (n=3), valve replacement (n=2), Ross procedure (n=1), and balloon valvuloplasty (n=1). Freedom from reintervention was 85.1+/-6.9%, 78.0+/-9.35%, and 53.5+/-15.9% at 5, 10, and 15 years, respectively. CONCLUSIONS: Primary surgical aortic valvotomy in early infancy carries a low early and late mortality, a low occurrence of significant aortic regurgitation and a low early recurrence of aortic stenosis. In great majority of cases, reintervention can be delayed to allow implantation of an adult-sized prosthesis, when required.     

What Do We Need beyond Hemoglobin A1c to Get the Complete Picture of

Hemoglobin A1c (HbA1c) is currently the most commonly used marker for the determination of the glycemic status in people with diabetes and it is frequently used to guide therapy and especially medical treatment of people with diabetes. The measurement of HbA1c has reached a high level of analytical quality and, therefore, this biomarker is currently also suggested to be used for the diagnosis of diabetes. Nevertheless, it is crucial for people with diabetes and their treating physicians to be aware of possible interferences during its measurement as well as physiological or pathological factors that contribute to the HbA1c concentration without being related to glycemia, which are discussed in this review. We performed a comprehensive review of the literature based on PubMed searches on HbA1c in the treatment and diagnosis of diabetes including its most relevant limitations, glycemic variability and self-monitoring of blood glucose (SMBG). Although the high analytical quality of the HbA1c test is widely acknowledged, the clinical relevance of this marker regarding risk reduction of cardiovascular morbidity and mortality is still under debate. In this respect, we argue that glycemic variability as a further risk factor should deserve more attention in the treatment of diabetes.