Controversies in ACL revision surgery: Italian expert group consensus and state of the art

Background: Revision ACL reconstruction is a complex topic with many controversies and not-easy-to-make decisions. The authors’ aim is to provide some feasible advice that can be applied in daily clinical practice with the goal of facilitating the decision-making process and improving the outcomes of patients subjected to revision ACL reconstruction. Methods: A national survey with seven questions about the most controversial topics in revision ACL reconstruction was emailed to members of two societies: SIOT and SIAGASCOT. The participants’ answers were collected, the most recent literature was analyzed, and a consensus was created by the authors, according to their long-term surgical experience. Conclusions: The decision-making process in revision ACL reconstruction starts with a standardized imaging protocol (weight-bearing radiographs, CT scan, and MRI). One-stage surgery is indicated in almost all cases (exceptions are severe tunnel enlargement and infection), while the choice of graft depends on the previously used graft and the dimensions of the tunnels, with better clinical outcomes obtained for autografts. Additional procedures such as lateral extra-articular tenodesis in high-grade pivot-shift knees, biplanar HTO in the case of severe coronal malalignment, and meniscal suture improve the clinical outcome and should be considered case by case. Level of evidence: V (Expert opinion)

Klassische Moderne. Un paradigma del Novecento

Il libro, che pubblica gli atti del convegno internazionale, svoltosi a Roma nel maggio del 2007 nell’ambito della ricerca PRIN-2005 (Università di Roma La Sapienza, Trento, Bari e Urbino), analizza il periodo della cultura tedesca della fine-secolo con particolare attenzione ai personaggi e ai movimenti che si sono collocati negli “spazi intermedi”, intesi non solo e non tanto come zone di confine in senso territoriale, quanto piuttosto come zone di interscambio culturale e disciplinare, come tentativi di “superamento” degli ordini mentali e culturali costituiti. L’ambito cronologico che il gruppo di ricerca prende in esame va da 1888 al 1933. La periodizzazione proposta vuole rinviare a quella serie di movimenti e di pensatori che hanno dato il via alla messa in discussione di quei valori costituiti, dalla cui frammentazione è nata la cultura del “secolo breve”. In questo periodo, a partire dalla Jahrhundertwende, sono state elaborate e sperimentate nella prassi letteraria e artistica, una serie di teorie, una serie di “visioni del mondo” che implicavano tanto una pratica produttiva quanto un ruolo dell’artista e dell’arte quanto una visione più generale dei cambiamenti epocali e dell’epoca moderna. Tali teorie e pratiche artistiche, di vario genere e di vario livello, costituiscono un patrimonio concettuale perché in esse si trovano sperimentate e a volte anticipate molte questioni che oggi sono di estrema attualità: dal rapporto uomo-macchina al rapporto parola-immagine, dalla definizione degli spazi urbani alla questione della guerra, dalla ricerca della identità monoculturale alla presa d’atto dell’esistenza dell’estraneo. Queste varie problematiche sono state espresse in termini linguistici nuovi giacché gli autori si sono posti – teoricamente e praticamente – il problema del linguaggio artistico e ne hanno modificato (a volte radicalmente) i codici espressivi. Il libro di divide in tre parti: I: Per una definizione della Klassische Moderne che presenta l’ampia e animata discussione sulla stessa definizione teorica del movimento artistico-culturale, sia sui termini cronologici di questa nuova periodizzazione. Questa parte raccoglie i contributi di Aldo Venturelli, Helmut Kiesel e Fabrizio Cambi. II: La rivoluzione delle forme, che analizza la produzione delle avanguardie (sia pure definite “marginali” ) e prende in considerazione anche aspetti della produzione musicale, nonché forme di narratologia e nuove forme di scrittura. Questa seconda parte pubblica i saggi di Mauro Ponzi, Rosmarie Keller, Silvio Vietta, Hans Dieter Zimmermann, Elio Matassi e Sabine Meine. III: La fucina dei nuovi linguaggi che analizza l’innovazione dei linguaggi artistici sull’esempio di autori meno radicali che quelli delle avanguardie storiche. Questi autori, tipici esponenti della Klassische Moderne, hanno cercato di coniugare l’innovazione dei linguaggi con il recupero di alcuni aspetti della tradizione. Nella terza parte del volume vengono pubblicati i saggi di Alain Montandon, Giovanni Tateo, Gouseppe Farese, Gabriella Rovagnati, Sabine Schneider e Alessandro Fambrini

Quantification Bias Caused by Plasmid DNA Conformation in Quantitative Real-Time PCR Assay

Quantitative real-time PCR (qPCR) is the gold standard for the quantification of specific nucleic acid sequences. However, a serious concern has been revealed in a recent report: supercoiled plasmid standards cause significant over-estimation in qPCR quantification. In this study, we investigated the effect of plasmid DNA conformation on the quantification of DNA and the efficiency of qPCR. Our results suggest that plasmid DNA conformation has significant impact on the accuracy of absolute quantification by qPCR. DNA standard curves shifted significantly among plasmid standards with different DNA conformations. Moreover, the choice of DNA measurement method and plasmid DNA conformation may also contribute to the measurement error of DNA standard curves. Due to the multiple effects of plasmid DNA conformation on the accuracy of qPCR, efforts should be made to assure the highest consistency of plasmid standards for qPCR. Thus, we suggest that the conformation, preparation, quantification, purification, handling, and storage of standard plasmid DNA should be described and defined in the Minimum Information for Publication of Quantitative Real-Time PCR Experiments (MIQE) to assure the reproducibility and accuracy of qPCR absolute quantification

The isochore organization and the compositional distribution of homologous coding sequences in the nuclear genome of plants

18 p.-7 fig.-1 tab.The isochore structure of the nuclear genome of angiosperms described by Salinas et al. (1) was confirmed by using a different experimental approach, namely by showing that the levels of coding sequences from both dicots and Gramineae are linearly correlated with GC levels of the corresponding flanking sequences. The compositional distribution of homologous coding sequences from several orders of dicots and from Gramineae were also studied and shown to mimick the compositional distributions previously seen (l)for coding sequences in general, most coding sequences from Gramineae being much higher than those of the dicots explored. Thfese differences were even stronger for third codon positions and led to striking codon usages for many coding sequences especially in the case of Gramineae.Peer reviewe

Chromosomal location effects on gene sequence evolution in mammals

AbstractBackground: Nucleotide substitution rates and G + C content vary considerably among mammalian genes. It has been proposed that the mammalian genome comprises a mosaic of regions – termed isochores – with differing G + C content. The regional variation in gene G + C content might therefore be a reflection of the isochore structure of chromosomes, but the factors influencing the variation of nucleotide substitution rate are still open to question.Results: To examine whether nucleotide substitution rates and gene G + C content are influenced by the chromosomal location of genes, we compared human and murid (mouse or rat) orthologues known to belong to one of the chromosomal (autosomal) segments conserved between these species. Multiple members of gene families were excluded from the dataset. Sets of neighbouring genes were defined as those lying within 1 centiMorgan (cM) of each other on the mouse genetic map. For both synonymous substitution rates and G + C content at silent sites, neighbouring genes were found to be significantly more similar to each other than sets of genes randomly drawn from the dataset. Moreover, we demonstrated that the regional similarities in G + C content (isochores) and synonymous substitution rate were independent of each other.Conclusions: Our results provide the first substantial statistical evidence for the existence of a regional variation in the synonymous substitution rate within the mammalian genome, indicating that different chromosomal regions evolve at different rates. This regional phenomenon which shapes gene evolution could reflect the existence of ‘evolutionary rate units’ along the chromosome

Compositional bimodality of the nuclear genome of tobacco.

We have studied the compositional distribution of six genes (or small multigene families) and of one family of transposable elements, Tnt1, in DNA fractions from tobacco (Nicotiana tabacum) separated according to base composition. We have shown that gene distribution is bimodal and that such bimodality is due to the different base composition of the two parental genomes of tobacco (N.sylvestris and N.tomentosiformis) and to the different parental origin of the genes tested. These results indicate a physical separation and an absence of extensive recombination of the parental genomes, which have been together in the tobacco nucleus for a small span of their evolutionary life, and a conservation of their compositional patterns, including gene localization

Compositional compartmentalization and compositional patterns in the nuclear genomes of plants.

We report here results which indicate (i) that the nuclear genomes of angiosperms is characterized by a compositional compartmentalization and an isochore structure; and (ii) that the nuclear genomes of some Gramineae exhibit strikingly different compositional patterns compared to those of many dicots. Indeed, the compositional distribution of nuclear DNA molecules (in the 50-100 Kb size range) from three dicots (pea, sunflower and tobacco) and three monocots (maize, rice and wheat) were found to be centered around lower (41%) and higher (45% for rice, 48% for maize and wheat) GC levels, respectively (and to trail towards even higher GC values in maize and wheat). Experiments on gene localization in density gradient fractions showed a remarkable compositional homogeneity in vast (greater than 100-200 Kb) regions surrounding the genes. On the other hand, the compositional distribution of coding sequences (GenBank and literature data) from dicots (several orders) was found to be narrow, symmetrical and centered around 46% GC, that from monocots (essentially barley, maize and wheat) to be broad, asymmetrical and characterized by an upward trend towards high GC values, with the majority of sequences between 60 and 70% GC. Introns exhibited a similar compositional distribution, but lower GC levels, compared to exons from the same genes

Gene distribution and isochore organization in the nuclear genome of plants.

The genomic distribution of 23 nuclear genes from three dicotyledons (pea, sunflower, tobacco) and five monocotyledons of the Gramineae family (barley, maize, rice, oat, wheat) was studied by localizing these genes in DNA fractions obtained by preparative centrifugation in Cs2SO4/BAMD density gradients. Each one of these genes (and of many other related genes and pseudogenes) was found to be located in DNA fragments (50-100 Kb in size) that were less than 1-2% GC apart from each other. This definitively demonstrates the existence of isochores in plant genomes, namely of compositionally homogeneous DNA regions at least 100-200 Kb in size. Moreover, the GC levels of the 23 coding sequences studied, of their first, second and third codon positions, and of the corresponding introns were found to be linearly correlated with the GC levels of the isochores harboring those genes. Compositional correlations displayed increasing slopes when going from second to first to third codon position with obvious effects on codon usage. Coding sequences for seed storage proteins and phytochrome of Gramineae deviate from the compositional correlations just described. Finally, CpG doublets of coding sequences were characterized by a shortage that decreased and vanished with increasing GC levels of the sequences. A number of these findings bear a striking similarity with results previously obtained for vertebrate genes

The isochore organization and the compositional distribution of homologous coding sequences in the nuclear genome of plants.

The isochore structure of the nuclear genome of angiosperms described by Salinas et al. (1) was confirmed by using a different experimental approach, namely by showing that the levels of coding sequences from both dicots and Gramineae are linearly correlated with GC levels of the corresponding flanking sequences. The compositional distribution of homologous coding sequences from several orders of dicots and from Gramineae were also studied and shown to mimick the compositional distributions previously seen (1) for coding sequences in general, most coding sequences from Gramineae being much higher than those of the dicots explored. These differences were even stronger for third codon positions and led to striking codon usages for many coding sequences especially in the case of Gramineae