The fifty most cited Italian articles in the orthopaedic literature

PURPOSES

It is widely known that in Orthopaedics, as in each specialty, the academic influence of an article is also determined by the number of times the article is cited. The aim of this study was to identify the 50 most frequently cited Italian orthopaedics journal articles and to analyse the characteristics that might have made them more citable.

METHODS

Science Citation Index Expanded was searched for the 50 most frequently cited Italian orthopaedics journal articles between 1988 and 2013 in the subject category "Orthopaedics".

RESULTS

The 50 most frequently cited articles were all published in English and were published in 12 of the 67 journals in the subject category "Orthopaedics" in the Institute for Scientific Information Web Science (Thomson Reuters, New York, New York, USA). One half of the articles were published before 2000 and the other half later. The number of citations ranged from 423 of the first article (mean citation/years 21.15) to 83 of the fiftieth (mean citation/years 16.60). The articles were all categorized under orthopaedic field, but each of them spanned from orthopaedics to a specific sub-specialty. The majority was clinical articles (n = 39), and the most common fields were sport orthopaedic surgery (including arthroscopy and cartilage) (n = 19) and biomechanics (n = 12).

CONCLUSIONS

This list of 50 most frequently cited Italian articles is, to our knowledge, significantly important for the general orthopaedic scientific community, particularly for the Italian orthopaedic community. Researchers and doctors may use this work to make their future publications more influential and citable.

Mössbauer cell for low-temperature studies of catalysts under reaction conditions

Mössbauer spectroscopy is an essential tool to investigate the structure of Fe supported catalysts and their changes, when they are used in the Fischer-Tropsch synthesis. A cell, that allows keeping the samples in the same atmosphere of the reduction treatment, was designed in order to characterize the Fe species without changing the working atmosphere avoiding the oxidation. It allows to measure at low temperatures in a helium closed-cycle refrigerator. Besides, this cell is useful to perform Mössbauer measurements on the used catalysts, preserving the oxidation of its species, using an inert atmosphere. In this work, we describe the details of this new cell and, as an example of its utility, we present the results obtained with a system of 12 nm iron oxide nanoparticles supported on a mesoporous silica matrix.

GAPDH enhances the aggressiveness and the vascularization of non-Hodgkin's B lymphomas via NF-κB-dependent induction of HIF-1α

Deregulated expression of glycolytic enzymes contributes not only to the increased energy demands of transformed cells but also has non-glycolytic roles in tumors. However, the contribution of these non-glycolytic functions in tumor progression remains poorly defined. Here, we show that elevated expression of glyceraldehyde-3-phosphate dehydrogenase (GAPDH), but not of other glycolytic enzymes tested, increased aggressiveness and vascularization of non-Hodgkin's lymphoma. Elevated GAPDH expression was found to promote nuclear factor-κB (NF-κB) activation via binding to tumor necrosis factor receptor-associated factor-2 (TRAF2), enhancing the transcription and the activity of hypoxia-inducing factor-1α (HIF-1α). Consistent with this, inactive mutants of GAPDH failed to bind TRAF2, enhance HIF-1 activity or promote lymphomagenesis. Furthermore, elevated expression of gapdh mRNA in biopsies from diffuse large B-cell non-Hodgkin's lymphoma patients correlated with high levels of hif-1α, vegf-a, nfkbia mRNA and CD31 staining. Collectively, these data indicate that deregulated GAPDH expression promotes NF-κB-dependent induction of HIF-1α and has a key role in lymphoma vascularization and aggressiveness.

Cluster phases of decorated micellar solutions with macrocyclic ligands

An aqueous self-assembled micellar system (sodium dodecyl sulfate, SDS, decorated with various adhesive sites, cryptand Kryptofix 222 and crown ether 18-Crown-6 molecules) has been investigated by dynamic light scattering (DLS) and small angle x-ray scattering (SAXS) to have insights into the micellar structure, the micellar interactions, and the aggregation properties of the system. DLS demonstrates the existence of populations of aggregates in the submicrometer/micrometer range, while the Guinier analysis of the SAXS curves helps in detailing objects smaller than 30 nm. The aggregates of micelles are here named cluster phases of micelles (CPMs). Considering that SDS micelles in water do not aggregate at low concentration, it is shown that macrocyclic ligands induce the SDS micelle aggregation as a function of the concentration (i.e., investigated ligand/SDS molar ratios are 5.0, 1.5, 1.0, and 0.5) and hydrophobicity of the adhesive sites. The sizes and the percentages of the micelles and the CPMs have been monitored to test the stability and reversibility of the system. DLS results clearly show that the aggregation processes of the decorated micelles are reproducible at time intervals of the order of 1 month, while the stability may not be entirely maintained after a year. As an issue of particular relevance, the higher the ligand/surfactant molar ratio, the larger are the CPMs induced. The K222 ligand results in being more effective in promoting the micellar aggregation than 18C6 as a consequence of the different hydrophobicity.

β-Connectin studies by small-angle x-ray scattering and single-molecule force spectroscopy by atomic force microscopy

The three-dimensional structure and the mechanical properties of a β-connectin fragment from human cardiac muscle, belonging to the I band, from I(27) to I(34), were investigated by small-angle x-ray scattering (SAXS) and single-molecule force spectroscopy (SMFS). This molecule presents an entropic elasticity behavior, associated to globular domain unfolding, that has been widely studied in the last 10 years. In addition, atomic force microscopy based SMFS experiments suggest that this molecule has an additional elastic regime, for low forces, probably associated to tertiary structure remodeling. From a structural point of view, this behavior is a mark of the fact that the eight domains in the I(27)-I(34) fragment are not independent and they organize in solution, assuming a well-defined three-dimensional structure. This hypothesis has been confirmed by SAXS scattering, both on a diluted and a concentrated sample. Two different models were used to fit the SAXS curves: one assuming a globular shape and one corresponding to an elongated conformation, both coupled with a Coulomb repulsion potential to take into account the protein-protein interaction. Due to the predominance of the structure factor, the effective shape of the protein in solution could not be clearly disclosed. By performing SMFS by atomic force microscopy, mechanical unfolding properties were investigated. Typical sawtooth profiles were obtained and the rupture force of each unfolding domain was estimated. By fitting a wormlike chain model to each peak of the sawtooth profile, the entropic elasticity of octamer was described.

Dynamic light scattering and atomic force microscopy imaging on fragments of beta-connectin from human cardiac muscle

In order to investigate the protein folding-unfolding process, dynamic light scattering (DLS) and atomic force microscopy (AFM) imaging were used to study two fragments of the muscle cardiac protein beta-connectin, also known as titin. Both fragments belong to the I band of the sarcomer, and they are composed of four domains from I(27) to I(30) (tetramer) and eight domains from I(27) to I(34) (octamer). DLS measurements provide the size of both fragments as a function of temperature from 20 up to 86 degrees C, and show a thermal denaturation due to temperature increase. AFM imaging of both fragments in the native state reveals a homogeneous and uniform distribution of comparable structures. The DLS and AFM techniques turn out to be complementary for size measurements of the fragments and fragment aggregates. An unexpected result is that the octamer folds into a smaller structure than the tetramer and the unfolded octamer is also smaller than the unfolded tetramer. This feature seems related to the significance of the hydrophobic interactions between domains of the fragment. The longer the fragment, the more easily the hydrophobic parts of the domains interact with each other. The fragment aggregation behavior, in particular conditions, is also revealed by both DLS and AFM as a process that is parallel to the folding-unfolding transition.

The impact of FDA and EMEA guidelines on drug development in relation to Phase 0 trials

An increase in the number of identified therapeutic cancer targets achieved through recent biomedical research has resulted in the generation of a large number of molecules that need to be tested further. Current development of (anticancer) drugs is a rather inefficient process that for an average new molecule takes around 10–15 years. It is also a challenging process as it is associated with high costs and a low rate of approval. It is known that less than 10% of new molecular entities entering clinical Phase I testing progress beyond the investigational programme and reach the market; this probability is even lower for anticancer agents. In 2003, the US Food and Drug Administration (US FDA) declared the urgent need for new toolkits to improve the critical development path that leads from scientific discovery to the patient. In this scenario, Phase 0 (zero) trials should allow an early evaluation in humans of pharmacokinetic and pharmacodynamic profiles of test compounds through administration of sub-pharmacological doses and for a short time period to a low number of humans. Typically, Phase 0 studies have no therapeutic or diagnostic intent. Owing to the low doses administered and the low risk of toxicity, shorter preclinical packages to support these studies are required. Phase 0 trials have been proposed to help in making an early selection of promising candidates for further evaluation in Phase I–III trials, providing a potentially useful instrument for drug discovery, particularly in the field of oncology. Phase 0 studies are expected to reduce costs of drug development, and to limit the preclinical in vitro and in vivo testing and the time period of drug development. However, there are also concerns about the utility and feasibility of Phase 0 studies. In January 2006, guidelines on exploratory investigational new drug studies in humans have been published by the US FDA, and currently a Phase 0 programme is ongoing at the National Cancer Institute to evaluate the impact (feasibility and utility) of Phase 0 studies on drug development. In Europe, a Position Paper produced by the Evaluation of Medicinal Products (EMEA) in 2004 raised the possibility of a reduced preclinical safety package to support early microdose clinical studies, and, as announced by a recent Concept Paper on medicinal products published by the committee for medicinal products for human use of the EMEA, EMEA's guidelines on Phase 0 studies are expected shortly. The true impact of Phase 0 studies on the drug development process as well as on the safety needs to be carefully explored.

[A follow-up study to assess stress and burnout in healthcare workers. Preliminary data]

To compare data obtained in a pilot study (2002) which evaluated the risk from exposure to stress and burnout in health care workers, the same three subjective questionnaires were administered: the Job Content Questionnaire (JCQ), the State-Trait Anxiety Inventory (STAI), the Maslach Burnout Inventory (MBI). The evaluation considered 294 workers employed in eight units: two of the six previous units were reorganized in four subunits. Preliminary data showed that questionnaires' scores have a concordant trend in the different units, as observed in 2002, confirming the validity of the instruments adopted. Results indicated a decreased level of the perceived stress in all the units, especially in the Third Division. We can hypothesize that the new organization, workers' turnover during the 5 years and the effect due to individual variables could have contribute to the observed variation. No significant associations, compared to 2002, between questionnaires' scores and task were found. Further evaluations, including measurement of objective parameters, will be carried out to complete the follow-up study and to determine which variables could have a role in the variation of the levels of stress and burnout's subjective perception.

[Occupational exposure to manganese in ferroalloy industry: neurobehavioral effects in a workers' cohort]

Our Institute has been following for 20 years a group of workers of a ferroalloy industry in order to evaluate neurobehavioral effects due to manganese exposure. Five years after the last study we have planned another one, to evaluate differences in neuromotor e cognitive functions between exposed and controls and to perform a longitudinal evaluation of the results. Environmental and biological sampling were collected, liver and kidney functionality, haemochrome, iron metabolism and sieric prolactine were evaluated. Several tests were administered: postural evaluation, tremor, four tests of the SPES battery, Pursuing Aiming, five tests of the Luria Nebraska Motor Battery, Raven Progressive Matrices, Trail Making Test, Mood Scale, Brief Symptoms Inventory, neuropsychological symptoms questionnaire. Personal habits and working, living and clinical histories were collected. We evaluated 43 exposed workers and 40 controls. Exposure indicators resulted all significantly higher in exposed workers. Neuropsychological examination showed differences in Raven Progressive Matrices and Pursuit Aiming, higher tremor values and differences in postural evaluation between exposed and controls.