Densitometric changes of the patella in patients undergoing unilateral knee arthroplasty.

INTRODUCTION: Although the intervention of knee arthroplasty became routine, there is no standard reference on the densitometric characteristics of the patella before and after surgery. Scope of this work is the evaluation of patellar bone density before and after unilateral knee arthroplasty. PATIENTS AND METHODS: BMD was assessed by DEXA examination in 146 individuals, who have been divided into three distinct groups. Group I: 68 subjects with a mean age of 70.6 years, with an unilateral femoral-tibial knee prothesis. Group II: healthy subjects of similar age (average: 64) and without implants. Group III: healthy adults with a mean age of 26.6 years. The follow-up was performed at 6 months to a maximum of 2 years post surgery. RESULTS: The results were obtained from 68 subjects examined with the DEXA software dedicated to the forearm, which turned out to be the most appropriate for our purpose. The follow-up performed every 6 months after surgery showed a reduction of the density values in the operated knee in the 1st control with a return to the pre-surgiucal situation in the control performed after 1 year. In subsequent checks there was a further increase of the patellar density of the operated knee. CONCLUSION: Patellar DEXA examination is recommended as an addition to the clinical and radiological standard examination.

Mental images across the adult lifespan: a behavioural and fMRI investigation of motor execution and motor imagery.

Motor imagery (M.I.) is a mental state in which real movements are evoked without overt actions. There is some behavioural evidence that M.I. declines with ageing. The neurofunctional correlates of these changes have been investigated only in two studies, but none of the these studies has measured explicit correlations between behavioural variables and the brain response, nor the correlation of M.I. and motor execution (M.E.) of the same acts in ageing. In this paper, we report a behavioural and functional magnetic resonance imaging (fMRI) experiment that aimed to address this issue. Twenty-four young subjects (27 ± 5.6 years) and twenty-four elderly subjects (60 ± 4.6 years) performed two block-design fMRI tasks requiring actual movement (M.E.) or the mental rehearsal (M.I.) of finger movements. Participants also underwent a behavioural mental chronometry test in which the temporal correlations between M.I. and M.E. were measured. We found significant neurofunctional and behavioural differences between the elderly subjects and the young subjects during the M.E. and the M.I. tasks: for the M.E. task, the elderly subjects showed increased activation in frontal and prefrontal (pre-SMA) cortices as if M.E. had become more cognitively demanding; during the M.I. task, the elderly over-recruited occipito-temporo-parietal areas, suggesting that they may also use a visual imagery strategy. We also found between-group behavioural differences in the mental chronometry task: M.I. and M.E. were highly correlated in the young participants but not in the elderly participants. The temporal discrepancy between M.I. and M.E. in the elderly subjects correlated with the brain regions that showed increased activation in the occipital lobe in the fMRI. The same index was correlated with the premotor regions in the younger subjects. These observations show that healthy elderly individuals have decreased or qualitatively different M.I. compared to younger subjects.

Risk assessment of aggression toward emergency health care workers.

BACKGROUND: Health care and social service workers face a significant risk of job-related violence. AIMS: To develop a method for quantitative evaluation of the risk of violence, as required by Italian and European regulations, against extra-hospital emergency health care workers employed by the Regional Emergency Healthcare Service (ARES 118) in the Lazio Region in Italy. METHODS: Violence to the ARES 118 workers during working hours was examined by analysing injuries reported by them between 2005 and 2007. The assessment method proposed should give a numerical indicator of the risk of violence for each homogeneous group. The quantitative risk was evaluated on the basis of variables such as the days off work for each episode, the total number of aggressive attacks, the type of health intervention involved, etc. RESULTS: The rate of accidents related to aggression during working hours at the ARES unit was 6.3%, which is significantly higher than the figure of 2% reported for the entire health care sector. CONCLUSIONS: The present evaluation is largely based on analysis of the Injury Register. To increase the sensitivity of the method so that it closely reflects active reporting of events, it would be necessary to implement a procedure for reporting events in a 'company register of acts of violence' and to make workers more aware of the need to report all such episodes.

No evidence of colonization with community-acquired methicillin-resistant Staphylococcus aureus in HIV-1-infected men who have sex with men.

To assess the prevalence of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) colonization in HIV-1-infected men who have sex with men (MSM), a cross-sectional study was conducted on 104 persons attending a large STI/HIV unit in Rome, Italy in the period June 2007-June 2008. Swabs obtained from both anterior nares and S. aureus isolates were characterized by phenotypic and genotypic methods. A total of 24 individuals (23.1%) were colonized with S. aureus but none carried MRSA. No statistically significant association between colonization with S. aureus and behavioural, clinical, virological or immunological characteristics was identified. This study indicates a lack of circulation of CA-MRSA in HIV-1-infected MSM in Italy and underscores large epidemiological differences between the USA and a European country, so that only locally conducted epidemiological studies can provide insight into the local circulation of CA-MRSA in general and selected populations.

Urbanization Affects Composition but Not Richness of Flower Visitors in the Yungas of Argentina.

Urban areas represent a spatially small impact in relation to other land-uses such as livestock and agriculture, but they undergo rapid changes. Such changes involve their size, shape, interconnectivity, and composition of natural patches. Habitat loss generated by urbanization affects the diversity and abundance of bees and other flower visitors in many sites. In general, the presence of urban areas represents a strict boundary to flower visitors and restricts their movement between natural and suburban habitat patches. The aim of this work is to evaluate how the flower visitor assemblage change along an urban-natural gradient in northwest Argentina. We established five areas in the Yungas ecoregion and sampled three sites with different degrees of urbanization (urban, suburban, and natural), at each area, reaching 15 sites. At each site, we sampled flower visitors during 5-min observation periods done over flowering plants. We found 197 morphospecies of flower-visiting insects along the gradient and an invariant richness, abundance, and Shannon diversity. The assemblage presented the same taxonomic group distributions in the three categories established. However, in urban sites, solitary bees and bees with soil borrowing nesting type predominate, while eusocial and cavity nesting bees were the main flower visitors in suburban sites. Our results suggest that the cities of northwestern Argentina are not a strict boundary for flower visitors; however, urbanization seems to be selecting and favoring certain flower-visitor species traits.

Transglutaminase-mediated modifications of the rat sperm surface in vitro.

Two transglutaminase-mediated modifications of the rat epididymal spermatozoon surface were demonstrated in vitro. Transglutaminase was effective in promoting the binding of spermidine to the sperm. Moreover, the enzyme, by reacting with one of the major proteins secreted by the rat seminal vesicle epithelium, produced a modified form of the protein with a higher molecular weight and the capability of binding to the sperm cells. A specific physiological role for the enzyme, bringing about modifications of the rat sperm surface in the seminal fluid environment, is suggested.

Efficacy of treatment with percutaneous vertebroplasty and kyphoplasty for traumatic fracture of thoracolumbar junction.

AIM: The aim of this paper was to assess the efficacy of a minimally invasive treatment with percutaneous vertebroplasty and kyphoplasty for traumatic fracture of thoracolumbar junction. Treatment of stable traumatic vertebral fractures of the thoracolumbar junction without neurological deficit is still controversy. Conservative treatment, characterized by discomfort and limitation in patient mobility, was progressively replaced by minimally invasive techniques such as percutaneous vertebroplasty and kyphoplasty. METHODS: Between January 2003 and August 2005, 34 patients suffering from 42 thoracolumbar fractures were treated at Neurosurgical Department of Istituto Galeazzi (Milan). The treatment selected (vertebroplasty versus kyphoplasty), depended on age of patients, timing and type of fracture. Results were clinically assessed by Visual Analogue Score (VAS) and Oswestry Disability Index. RESULTS: Mean preoperative VAS was 8.32 (range 5-10). Percutaneous vertebroplasty was performed in 25 cases (73.5%); while 9 patients were treated by kyphoplasty (27.5%); 27 patients showed a single level and 7 multilevel of the fractures. No complications occurred (infection, neurological deficit, embolic events) after treatment. At the early follow-up 91.7% of the patients achieved a good pain control already after 24 hours. Pain relief and disability, analyzed by VAS and Oswestry Disability Index, showed a good results at late follow-up time. CONCLUSIONS: Percutaneous vertebroplasty and kyphoplasty are two safe and effective techniques for treatment of thoracolumbar traumatic fractures and allow a good pain-control and return to normal working activity and social life.

Structural, electrical and magnetic characterization of artificial ferromagnetic/superconducting (La(0.7)Ca(0.3)MnO(3)/YBa(2)Cu(3)O(7-x)) heterostructures.

The fabrication and characterization of superconducting and ferromagnetic heterostructures is an open field due to the fundamental interest in the physics of the coexistence of these two competing orders and their possible applications in the spintronics industry. In this paper we present structural, electrical and magnetic characterization for the single La(0.7)Ca(0.3)MnO(3) (LCMO) thin layer, La(0.7)Ca(0.3)MnO(3)/YBa(2)Cu(3)O(7-x) (LCMO/YBCO) bilayers and the LCMO/YBCO/LCMO trilayers. In particular, we show a detailed magnetic characterization of the LCMO thin films by means of low temperature magnetic force microscopy. We discuss the different dynamics of the magnetic domains observed, depending on the substrate induced strain and on the film thickness.

Precursory worldwide signatures of earthquake occurrences on Swarm satellite data.

The study of the preparation phase of large earthquakes is essential to understand the physical processes involved, and potentially useful also to develop a future reliable short-term warning system. Here we analyse electron density and magnetic field data measured by Swarm three-satellite constellation for 4.7 years, to look for possible in-situ ionospheric precursors of large earthquakes to study the interactions between the lithosphere and the above atmosphere and ionosphere, in what is called the Lithosphere-Atmosphere-Ionosphere Coupling (LAIC). We define these anomalies statistically in the whole space-time interval of interest and use a Worldwide Statistical Correlation (WSC) analysis through a superposed epoch approach to study the possible relation with the earthquakes. We find some clear concentrations of electron density and magnetic anomalies from more than two months to some days before the earthquake occurrences. Such anomaly clustering is, in general, statistically significant with respect to homogeneous random simulations, supporting a LAIC during the preparation phase of earthquakes. By investigating different earthquake magnitude ranges, not only do we confirm the well-known Rikitake empirical law between ionospheric anomaly precursor time and earthquake magnitude, but we also give more reliability to the seismic source origin for many of the identified anomalies.

New perspectives in the study of the Earth's magnetic field and climate connection: The use of transfer entropy.

The debated question on the possible relation between the Earth's magnetic field and climate has been usually focused on direct correlations between different time series representing both systems. However, the physical mechanism able to potentially explain this connection is still an open issue. Finding hints about how this connection could work would suppose an important advance in the search of an adequate physical mechanism. Here, we propose an innovative information-theoretic tool, i.e. the transfer entropy, as a good candidate for this scope because is able to determine, not simply the possible existence of a connection, but even the direction in which the link is produced. We have applied this new methodology to two real time series, the South Atlantic Anomaly (SAA) area extent at the Earth's surface (representing the geomagnetic field system) and the Global Sea Level (GSL) rise (for the climate system) for the last 300 years, to measure the possible information flow and sense between them. This connection was previously suggested considering only the long-term trend while now we study this possibility also in shorter scales. The new results seem to support this hypothesis, with more information transferred from the SAA to the GSL time series, with about 90% of confidence level. This result provides new clues on the existence of a link between the geomagnetic field and the Earth's climate in the past and on the physical mechanism involved because, thanks to the application of the transfer entropy, we have determined that the sense of the connection seems to go from the system that produces geomagnetic field to the climate system. Of course, the connection does not mean that the geomagnetic field is fully responsible for the climate changes, rather that it is an important driving component to the variations of the climate.

237 ACoA aneurysms clipped or embolized. Outcomes measurement using the De Santis-CESE assessment tool.

AIM: The aim of this retrospective study was to demonstrate the difference in patient outcomes after treatment for bleeding endocranial aneurysms when evaluated with methods based on different assessment criteria. METHODS: The outcome of 237 patients, 141 of which were operated on for anterior communicating artery aneurysm and 96 embolized, was assessed by a new method developed by De Santis. The patients operated on were assessed by the Glasgow Outcome Scale (GOS) and Rank Disability Scale (RDS) and the results of the latter were compared with the new method, the De Santis-CESE (Clinical Emotional Social Evaluation) method, which consists of a clinical evaluation and a numeric scoring system based on seven standard points. Comparison between the three methods showed significantly different outcomes. Patients who underwent surgical operation showed changes in character and behaviour, whereas the others showed cognitive, emotional and sexual habit changes. CONCLUSION: Compared with the GOS and RDS instruments, the CESE method showed significant differences in patient outcome assessment, particularly regarding best outcomes. These differences may be due to the greater sensitivity of the CESE method over the other two scales. Furthermore, surgical patients seemed to achieve a better outcome than endovascular patients. The authors intend to conduct a prospective study to test the results obtained in this retrospective study.

[Organization of workplace first aid in health care facilities]. / L'organizzazione del pronto soccorso nelle strutture sanitarie.

BACKGROUND: Laws D.Lgs. 626/94 and D.I. 388/03 attach particular importance to the organization of first aid in the workplace. Like every other enterprise, also hospitals and health care facilities have the obligation, as foreseen by the relevant legislation, to organize and manage first aid in the workplace. OBJECTIVES: To discuss the topic in the light of the guidelines contained in the literature. METHODS: We used the references contained in the relevant literature and in the regulations concerning organization of first aid in health care facilities. RESULTS: The regulations require the general manager of health care facilities to organize the primary intervention in case of emergencies in all health care facilities (health care or administrative, territorial and hospitals). CONCLUSIONS: In health care facilities the particular occupational risks, the general access of the public and the presence of patients who are already assumed to have altered states of health, should be the reason for particular care in guaranteeing the best possible management of a health emergency in the shortest time possible.

Optimal segmentation of pupillometric images for estimating pupil shape parameters.

The problem of determining the pupil morphological parameters from pupillometric data is considered. These characteristics are of great interest for non-invasive early diagnosis of the central nervous system response to environmental stimuli of different nature, in subjects suffering some typical diseases such as diabetes, Alzheimer disease, schizophrenia, drug and alcohol addiction. Pupil geometrical features such as diameter, area, centroid coordinates, are estimated by a procedure based on an image segmentation algorithm. It exploits the level set formulation of the variational problem related to the segmentation. A discrete set up of this problem that admits a unique optimal solution is proposed: an arbitrary initial curve is evolved towards the optimal segmentation boundary by a difference equation; therefore no numerical approximation schemes are needed, as required in the equivalent continuum formulation usually adopted in the relevant literature.

The induction kinetics of bacterial photophosphorylation. Threshold effects by the phosphate potential and correlation with the amplitude of the carotenoid absorption band shift.

1. ATP synthesis (monitored by luciferin-luciferase) can be elicited by a single turnover flash of saturating intensity in chromatophores from Rhodopseudomonas capsulata, Kb1. The ATP yield from the first to the fourth turnover is strongly influenced by the phosphate potential: at high phosphate potential (-11.5 kcal/mol) no ATP is formed in the first three turnovers while at lower phosphate potential (-8.2 kcal/mol) and the yield in the first flash is already one half of the maximum, which is reached after 2-3 turnovers. 2. The response to ionophores indicates that the driving force for ATP synthesis in the first 20 turnovers is mainly given by a membrane potential. The amplitude of the carotenoid band shift shows that during a train of flashes an increasing delta psi is built up, which reaches a stationary level after a few turnovers; at high phosphate potential, therefore, more turnovers of the same photosynthetic unit are required to overcome an energetic threshold. 3. After several (six to seven) flashes the ATP yield becomes constant, independently from the phosphate potential; the yield varies, however, as a function of dark time (td) between flashes, with an optimum for td = 160-320 ms. 4. The decay kinetics of the high energy state generated by a long (125 ms) flash have been studied directly measuring the ATP yield produced in post-illumination by one single turnover flash, under conditions of phosphate potential (-10 kcal/mol), which will not allow ATP formation by one single turnover. The high energy state decays within 20 s after the illumination. The decay rate is strongly accelerated by 10(-8) M valinomycin. 5. Under all the experimental conditions described, the amplitude of the carotenoid signal correlates univocally with the ATP yield per flash, demonstrating that this signal monitores accurately an energetic state of the membrane directly involved in ATP synthesis. 6. Although values of the carotenoid signal much larger than the minimal threshold are present, relax slowly, and contribute to the energy input for phosphorylation, no ATP is formed unless electron flow is induced by a single turnover flash. 7. The conclusions drawn are independent from the assumption that a delta psi between bulk phases is evaluable from the carotenoid signal.

Determination of lipid hydroperoxides in native low-density lipoprotein by a chemiluminescent flow-injection assay.

Lipid hydroperoxides have been implicated in the pathogenesis of atherosclerosis. This work was therefore set up to obtain a fast and specific chemiluminescent assay for measuring hydroperoxides in native low-density lipoprotein (LDL). The apparatus was a complete HPLC system including two pumps, an autosampler, a computer and a chemiluminescent detector with a T-mixing coil in the place of the column. Samples were injected from the autosampler and mixed with luminescent reagent (3 microM luminol and 1 microM microperoxidase in 0.1 M carbonate buffer (pH 10)) in the T-piece. To generate a calibration curve, linoleic acid hydroperoxide was obtained by incubating soybean lipoxygenase with linoleic acid. The calculated conjugated diene concentration was in good agreement with the nominal linoleic acid hydroperoxide concentration. The chemiluminescence was linear with the amount of linoleic acid hydroperoxide injected and the detection limit was about 3 pmol linoleic acid hydroperoxide. The chemiluminescence induced by copper-oxidized LDL was linear with concentration; the detection limit, when compared with linoleic acid hydroperoxide, was similar. The reproducibility of the linoleic acid hydroperoxide and of oxidized LDL hydroperoxide was examined in single pools. The coefficient of variation on the triplicates of each pool was about 3%. The titre of the linoleic acid hydroperoxide and oxidized LDL peroxides was quite stable for at least 10 days when stored under argon at 4 degrees C in the presence of EDTA. The mean value of the LDL hydroperoxides in 16 control subjects was 145.20 +/- 98.81 pmol/mg LDL protein. In conclusion, the microperoxidase-luminol-dependent chemiluminescence flow-injection assay is a rapid, sensitive and selective method for measuring lipid hydroperoxides in native LDL.

Changes of mitochondrial properties in maize seedlings associated with selection for germination at low temperature. Fatty acid composition, cytochrome c oxidase, and adenine nucleotide translocase activities

Mitochondria are affected by low temperature during seedling establishment in maize (Zea mays L.). We evaluated the associated changes in the mitochondrial properties of populations selected for high (C4-H) and low (C4-L) germination levels at 9.5 degreesC. When seedlings of the two populations were grown at 14 degreesC (near the lower growth limit), the mitochondrial inner membranes of C4-H showed a higher percentage of 18-carbon unsaturated fatty acids, a higher fluidity, and a higher activity of cytochrome c oxidase. We found a positive relationship between these properties and the activity of a mitochondrial peroxidase, allowing C4-H to reduce lipid peroxidation relative to C4-L. The specific activity of reconstituted ATP/ADP translocase was positively associated with this peroxidase activity, suggesting that translocase activity is also affected by chilling. The level of oxidative stress and defense mechanisms are differently expressed in tolerant and susceptible populations when seedlings are grown at a temperature near the lower growth limit. Thus, the interaction between membrane lipids and cytochrome c oxidase seems to play a key role in maize chilling tolerance. Furthermore, the divergent-recurrent selection procedure apparently affects the allelic frequencies of genes controlling such an interaction.

Purification and Characterization of Porin from Corn (Zea mays L.) Mitochondria.

Mitochondrial porin from corn (Zea mays L. B 73) shoots was solubilized with lauryl(dimethyl)-amine oxide and purified by chromatography on a hydroxyapatite:celite column. On sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the purified protein had an apparent molecular mass of 35 kD. When reconstituted in planar lipid bilayer membranes the porin formed ion-permeable channels with single-channel conductance of 2.0 and 4.0 nanosiemens in 1 M KCl. At low transmembrane voltages corn porin had the properties of a general diffusion pore with an estimated effective diameter of 1.6 nm and a small selectivity for anions over cations. The primary structure of corn porin seems to be quite different from that of other mitochondrial porins, because it did not cross-react with monoclonal antibodies against human porin and with polyclonal antibodies against yeast porin. Furthermore, the peptide maps of corn and bovine heart porins were very different. A sequence of 21 amino acids obtained by Edman degradation of peptides generated by porin proteolysis with Staphylococcus aureus V8 protease did not show any significant homology with known sequences of mitochondrial porins. Results of our investigation suggest that corn porin possesses functional properties similar to those of other mitochondrial porins, despite major structural differences.

[Educational and training issues in occupational first aid: the requisites for the teachers of the workers responsible for first aid]. / I requisiti per i formatori dei lavoratori designati al primo soccorso aziendale.

BACKGROUND: The inter-ministerial decree (D.I.) 388/03 (the Italian law on first aid in the workplace) attaches particular importance to the organization of first aid and to the content of the teaching and training of designated workers, specifying teaching objectives, programme and duration of courses. However it provides less details on the requirements and qualifications of the teachers and trainers. OBJECTIVES: To discuss this topic in the light of the guidelines contained in the literature and the existing legislation. METHODS: We used the specific references of literature and legislation concerning first aid training of designated workers. RESULTS: The objectives and the content of the training courses call for a high level of professional competence and approach. Therefore, training of designated workers should be planned and carried out in accordance with the training standards used for the teaching and training of the so-called "lay rescuers". CONCLUSIONS: The need to achieve high training standards for workers responsible for first aid at the workplace is to a large extent justified by the difficulty of the role of employees. This need follows the current tendency in regulations to guarantee adequate and up-dated training also for other agents operating within the system of workplace prevention. In this context the occupational physician plays a significant role in the training programmes for designated workers.

HAMP gene mutation c.208T>C (p.C70R) identified in an Italian patient with severe hereditary hemochromatosis.

Hepcidin is a recently identified hormone peptide involved in regulation of iron homeostasis. HAMP gene mutations have been described to date in five families with iron overload. We have identified the c.208T>C (p.C70R) mutation in the HAMP gene in a patient affected by a severe form of hereditary hemochromatosis. The variant, occurring in a highly conserved amino acid, disrupts one of the 4 intramolecular disulphide bonds present in hepcidin molecules of all vertebrates, and is presumably able to destabilize the peptide structure. The investigated patient was also found to harbor a heterozygous HFE c.845G>A (p.C282Y) mutation that may have contributed in increasing his iron burden.

Effect of plasma on the degradation of hydroperoxides of unesterified linoleic acid and copper-peroxidized LDL.

The determination of lipid hydroperoxides in plasma and lipoproteins recently reached a clinical relevance in disorders such as atherosclerosis, where oxidative reactions have been suggested to play a fundamental pathogenetic role. The peroxide content of lipoproteins is usually measured after ultracentrifugation and extraction. During this procedure, some peroxides might decompose causing a too low recovery. To screen this possibility, the disappearance, in the presence of human plasma, of hydroperoxides of linoleic acid and Cu-oxidized low density lipoprotein (LDL) have been investigated, using both a iodometric titration and an enzymatic assay. While only in the presence of GSH plasma decomposes linoleic acid hydroperoxides quite rapidly, peroxides in Cu-oxidized LDL were stable both in presence as well as in absence of GSH. This indicated that lipid hydroperoxides are stable in plasma and that peroxides of Cu-oxidized LDL are not substrate for the glutathione-dependent peroxidase activity in plasma. The relevant decrease of the iodometric titre of LDL peroxides observed in the presence of elevated amounts of plasma was shown to be artifactual, since some compounds extracted from plasma do react with iodine generated by peroxides. Whole plasma itself, indeed, has been shown to reduce back to I- appreciable amount of free iodine.