Does graded reaming affect the composition of reaming products in intramedullary nailing of long bones?

Reaming products taken during intramedullary nailing were examined to identify possible differences in their composition depending on the reaming percentage. Reaming products were taken from 39 fresh closed tibial and femoral diaphyseal fractures in patients with an average age of 29 years. According to histology, reaming products mainly consisted of bone trabeculae, viable or nonviable, and bone marrow stroma. A statistically significant reverse correlation exists between viable bone mass percentage and reaming progress. Reaming 1 mm less than the minimum canal diameter provides a higher viable bone mass percentage, which might be an important factor in the bone healing process.     

Effects of levosimendan on right ventricular function in patients with advanced heart failure

Right ventricular (RV) dysfunction frequently complicates advanced left ventricular heart failure and contributes to an unfavorable prognosis. Levosimendan is a novel inodilator that beneficially affects hemodynamics and left ventricular systolic and diastolic function in patients with advanced heart failure. However, its effects on RV function have not yet been properly assessed in these patients. In this randomized trial, the impact of levosimendan or placebo on various echocardiographic parameters of RV systolic and diastolic function was investigated in 54 patients with advanced heart failure due to left ventricular systolic dysfunction. Tissue Doppler imaging maximal systolic tricuspid annular velocity (S wave) increased significantly only in the levosimendan group (8.2 +/- 3.2 vs 9.0 +/- 3.0 cm/s, p <0.03). Tissue Doppler imaging RV early diastolic velocity (E wave) and the ratio of early to late diastolic velocities (E/A) also increased significantly after levosimendan administration (p <0.01 and p <0.05, respectively). Systolic pulmonary arterial pressure decreased significantly (54 +/- 11 vs 43 +/- 11 mm Hg, p <0.01) in the levosimendan-treated patients. Levosimendan beneficially modulated neurohormonal and inflammatory status by decreasing B-type natriuretic peptide levels (p <0.05) and by altering the ratio of interleukin-6 to interleukin-10 in favor of the latter (p <0.05). In conclusion, levosimendan could offer further therapeutic advantages in patients with advanced heart failure by improving systolic and diastolic RV function.     

Deletions of the INK4A gene occur in malignant peripheral nerve sheath tumors but not in neurofibromas

The INK4A gene, a candidate tumor suppressor gene located on chromosome 9p21, encodes two protein products, p16 and p19(ARF). p16 is a negative cell cycle regulator capable of arresting cells in the G1 phase by inhibiting cyclin-dependent kinases 4 (Cdk4) and 6 (Cdk6), thus preventing pRB phosphorylation. p19(ARF) prevents Mdm2-mediated neutralization of p53. Loss of INK4A is a frequent molecular alteration involved in the genesis of several neoplasms, including tumors of neuroectodermal origin. This study investigated the frequency of INK4A gene alterations in a series of malignant peripheral nerve sheath tumors (MPNSTs) and neurofibromas (NFs). INK4A gene and the p19(ARF)-specific exon 1beta were studied in 11 MPNST samples from 8 patients and 7 neurofibromas. Presence of INK4A deletions was assessed by Southern blotting hybridization and by a multiplex polymerase chain reaction (mPCR). INK4A point mutations were examined by single-strand conformation polymorphism (SSCP) and sequencing. The p16 promoter methylation status was determined by PCR amplification of bisulfite-treated DNA. Homozygous deletions of exon 2, thus affecting both p16 and p19(ARF), were identified in MPNSTs from 4 of 8 patients. Deletions, mutations, or silencing by methylation were not identified in the neurofibromas analyzed. Based on our results, we conclude that INK4A deletions are frequent events in MPNSTs and may participate in tumor progression. Silencing of p16 by methylation, which occurs often in several tumor types, is uncommon in MPNSTs.     

Meningococcal group C disease in Greece during 1993–2006: the impact of an unofficial single-dose vaccination scheme adopted by most paediatricians

The aim of this study was to evaluate the impact of the meningococcal C conjugate vaccine on the epidemiology of meningococcal C disease in Greece. Data from the National Reference Laboratory for Meningococcal Disease and a questionnaire distributed to Greek paediatricians were assessed. Since the introduction of the vaccine in 2001, 72% of Greek paediatricians have administered it as one single dose to patients aged > or =12 months. This vaccination scheme has probably contributed to a dramatic decrease in the number of meningococcal C infections, which reached zero in 2004.