Combined duodenal and pancreatic major trauma in high risk patients: can a partial reconstruction be safe?

Pancreatic trauma is an uncommon injury, occurring in only about 0.2% of blunt abdominal injuries, while duodenal injuries represent approximately 4% of all blunt abdominal injuries. When trauma of the pancreas and duodenum do not permit reparation, pancreatoduodenectomy (PD) is mandatory. In the reconstructive phase, the use of ductal ligation as an alternative to standard pancreaticojejunostomy has been reported by some authors. We report a case of polytrauma with pancreatic and duodenal injury in which the initial diagnosis failed to recognize the catastrophic duodenal and pancreatic situation. The patient was submitted for PD and the pancreatic stump was abandoned in the abdominal cavity after main pancreatic ductal ligation. This technique can minimize the morbidity and mortality of PD in patients with other organs or apparatus involved severely and extensively in trauma.

Pretreatment with sevoflurane attenuates direct lung injury.

BACKGROUND: Sevoflurane exerts effects on pulmonary cells that could protect against lung injury. We evaluated the potential of pretreatment with sevoflurane to attenuate lipopolysaccharide (LPS)-induced lung injury. METHODS: LPS was administered intratracheally in Wistar rats to induce lung injury. Sevoflurane was administered for 30 min at 0.25, 0.5 or 1.0 MAC 15 min before LPS or for 30 min at 0.5 MAC 24 hours before LPS. After initial analysis of bronchoalveolar lavage fluid (BALF) cells and total protein, the group of 0.5 MAC 15 min before LPS was further analyzed for surfactant aggregates subfractions, plasma malondialdehyde levels and lung histology. RESULTS: LPS instillation resulted in neutrophils sequestration in the lungs, loss of alveolar macrophages, increased BALF total protein and decreased large surfactant aggregates. Only inhalation of sevoflurane for 30 min at 0.5 MAC 15 min before LPS installation effectively reduced neutrophil accumulation, preserved alveolar epithelial cells and reduced total protein content in BALF. This regimen also reduced plasma malondialdehyde levels and increased large surfactant aggregates, despite the application of mechanical ventilation. This effect was preserved after LPS instillation and the favorable composition of surfactant was maintained. CONCLUSION: Pretreatment with sevoflurane effectively attenuates direct severe lung injury, possibly by inhibition of neutrophil accumulation and alteration of the surfactant composition.

On-chip manipulation of single photons from a diamond defect.

Operating reconfigurable quantum circuits with single photon sources is a key goal of photonic quantum information science and technology. We use an integrated waveguide device containing directional couplers and a reconfigurable thermal phase controller to manipulate single photons emitted from a chromium related color center in diamond. Observation of both a wavelike interference pattern and particlelike sub-Poissionian autocorrelation functions demonstrates coherent manipulation of single photons emitted from the chromium related center and verifies wave particle duality.

How does illness severity influence depression, health satisfaction and life satisfaction in patients with cardiovascular disease? The mediating role of illness perception and self-efficacy beliefs.

Numerous empirical studies have investigated the relationships between cardiovascular diseases (CVD) and patients' psychological well-being, with a focus almost exclusively on its dark side. Very little is known on the impact of illness severity on both negative and positive indicators of patients' well-being, as well as on the psychosocial variables that may mediate this association. Aim of the study was to investigate the impact of illness severity on depression as well as on health satisfaction and life satisfaction of patients undergoing a cardiovascular rehabilitation. It also aimed at testing the mediation of illness perception and self-efficacy beliefs in managing cardiac risk factors. The study involved 172 patients (mean age = 66.43 years; SD = 9.99 years; 76.2% men). Illness severity was measured in terms of left ventricular ejection fraction at discharge from the cardiology department, whereas all psychological dimensions were assessed one week later. Results showed significant relationships among illness severity, depression and health satisfaction that were fully mediated by illness perception and self-efficacy beliefs, but not significant relation between disease severity and life satisfaction (χ2 (1) = 2.30, p = n.s.). Overall, findings underline the importance of working on illness perception and self-efficacy beliefs to contrast depression and to improve health and life satisfaction in patients with CVD.

A biomechanical model of agonist-initiated contraction in the asthmatic airway.

This paper presents a modelling framework in which the local stress environment of airway smooth muscle (ASM) cells may be predicted and cellular responses to local stress may be investigated. We consider an elastic axisymmetric model of a layer of connective tissue and circumferential ASM fibres embedded in parenchymal tissue and model the active contractile force generated by ASM via a stress acting along the fibres. A constitutive law is proposed that accounts for active and passive material properties as well as the proportion of muscle to connective tissue. The model predicts significantly different contractile responses depending on the proportion of muscle to connective tissue in the remodelled airway. We find that radial and hoop-stress distributions in remodelled muscle layers are highly heterogenous with distinct regions of compression and tension. Such patterns of stress are likely to have important implications, from a mechano-transduction perspective, on contractility, short-term cytoskeletal adaptation and long-term airway remodelling in asthma.

Transient oscillatory force-length behavior of activated airway smooth muscle.

Airway smooth muscle (ASM) is cyclically stretched during breathing, even in the active state, yet the factors determining its dynamic force-length behavior remain incompletely understood. We developed a model of the activated ASM strip and compared its behavior to that observed in strips of rat trachealis muscle stimulated with methacholine. The model consists of a nonlinear viscoelastic element (Kelvin body) in series with a force generator obeying the Hill force-velocity relationship. Isometric force in the model is proportional to the number of bound crossbridges, the attachment of which follows first-order kinetics. Crossbridges detach at a rate proportional to the rate of change of muscle length. The model accurately accounts for the experimentally observed transient and steady-state oscillatory force-length behavior of both passive and activated ASM. However, the model does not predict the sustained decrement in isometric force seen when activated strips of ASM are subjected briefly to large stretches. We speculate that this force decrement reflects some mechanism unrelated to the cycling of crossbridges, and which may be involved in the reversal of bronchoconstriction induced by a deep inflation of the lungs in vivo.

Airway mechanics and methods used to visualize smooth muscle dynamics in vitro.

Contraction of airway smooth muscle (ASM) is regulated by the physiological, structural and mechanical environment in the lung. We review two in vitro techniques, lung slices and airway segment preparations, that enable in situ ASM contraction and airway narrowing to be visualized. Lung slices and airway segment approaches bridge a gap between cell culture and isolated ASM, and whole animal studies. Imaging techniques enable key upstream events involved in airway narrowing, such as ASM cell signalling and structural and mechanical events impinging on ASM, to be investigated.

Collective atomic recoil laser as a synchronization transition.

We consider here a model previously introduced to describe the collective behavior of an ensemble of cold atoms interacting with a coherent electromagnetic field. The atomic motion along the self-generated spatially periodic force field can be interpreted as the rotation of a phase oscillator. This suggests a relationship with synchronization transitions occurring in globally coupled rotators. In fact, we show that whenever the field dynamics can be adiabatically eliminated, the model reduces to a self-consistent equation for the probability distribution of the atomic "phases." In this limit, there exists a formal equivalence with the Kuramoto model, though with important differences in the self-consistency conditions. Depending on the field-cavity detuning, we show that the onset of synchronized behavior may occur through either a first- or second-order phase transition. Furthermore, we find a secondary threshold, above which a periodic self-pulsing regime sets in, that is immediately followed by the unlocking of the forward-field frequency. At yet higher, but still experimentally meaningful, input intensities, irregular, chaotic oscillations may eventually appear. Finally, we derive a simpler model, involving only five scalar variables, which is able to reproduce the entire phenomenology exhibited by the original model.

Characterizing dynamics with covariant Lyapunov vectors.

A general method to determine covariant Lyapunov vectors in both discrete- and continuous-time dynamical systems is introduced. This allows us to address fundamental questions such as the degree of hyperbolicity, which can be quantified in terms of the transversality of these intrinsic vectors. For spatially extended systems, the covariant Lyapunov vectors have localization properties and spatial Fourier spectra qualitatively different from those composing the orthonormalized basis obtained in the standard procedure used to calculate the Lyapunov exponents.

Synthesis, binding studies and in vivo biological evaluation of novel non-peptide antihypertensive analogues.

AT(1) antagonists (SARTANs) constitute the last generation of drugs for the treatment of hypertension, designed and synthesized to mimic the C-terminal segment of the vasoconstrictive hormone angiotensin II (AngII). They exert their action by blocking the binding of AngII on the AT(1) receptor. Up to date eight AT(1) antagonists have been approved for the regulation of high blood pressure. Although these molecules share common structural features and are designed to act under the same mechanism, they have differences in their pharmacological profiles and antihypertensive efficacy. Thus, there is still a need for novel analogues with better pharmacological and financial profiles. An example of a novel synthetic non peptide AT(1) antagonist which devoids the classical template of SARTANs is MM1. In vivo studies showed that MMK molecules, which fall in the same class of MM1, had a significant antihypertensive (40-80% compared to the drug losartan) activity. However, in vitro affinity studies showed that losartan has considerably higher affinity. The theoretical docking studies showed that MM1 acts on the same site of the receptor as losartan. They exert hydrophobic interactions with amino acid Val108 of the third helix of the AT(1) receptor and other hydrophobic amino acids in spatial vicinity. In addition, losartan favours multiple hydrogen bondings between its tetrazole group with Lys199. These additional interactions may in part explain its higher in vitro binding affinity.

Directed percolation with long-range interactions: Modeling nonequilibrium wetting.

It is argued that some phase transitions observed in models of nonequilibrium wetting phenomena are related to contact processes with long-range interactions. This is investigated by introducing a model where the activation rate of a site at the edge of an inactive island of length l is 1+a l(-sigma) . Mean-field analysis and numerical simulations indicate that for sigma>1 the transition is continuous and belongs to the universality class of directed percolation, while for 0

In vitro antioxidant activities of antioxidant-enriched toothpastes.

Several forms of periodontal diseases (PD) are often associated with modified phagocytosing leukocytes and contemporary free radical production. Host antioxidant defenses could benefit from toothpastes used as adjuncts to counteract plaque-associated bacteria. The aim of the present study was to determine possible antioxidant activity (AA) of 12 differently antioxidant-enriched toothpastes, regardless of their efficacy as antimicrobial agents. Toothpastes were enriched alternatively with sodium ascorbyl phosphate, alpha-tocopherol acetate, pycnogenol, allantoin and methyl salycilate or a mixture of these. AA was tested in a cell-free system with a ABTS-decolorization assay improved by means of a flow injection analysis device. Comet assay, using NCTC 2544 keratinocytes, was performed to test if it was possible to identify any protection against in vitro DNA fragmentation provoked by a challenge with H(2)O(2) in cultures pre-incubated with toothpaste extracts. Only toothpastes containing sodium ascorbyl phosphate displayed clear AA with I(50) values ranging between 50 and 80 mg of toothpaste/ml water. COMET analysis of cells challenged with H(2)O(2) in presence of toothpaste extracts revealed a limited protection exerted by sodium ascorbyl phosphate. The results described herein indicate that toothpastes containing sodium ascorbyl phosphate possess AA. All the data were obtained in systems in vitro and the demonstration of in vivo AA is desirable. These findings could be useful in the treatment and maintenance of some forms of PD and should be considered when arranging new toothpaste formulations.

Convective instabilities of synchronization manifolds in spatially extended systems.

We study the stability properties of anticipating synchronization in an open chain of unidirectionally coupled identical chaotic oscillators. Despite being absolutely stable, the synchronization manifold is unstable to propagating perturbations. We analyze and characterize such instabilities drawing a qualitative and quantitative comparison with the convective instabilities typical of spatially extended systems.

Wetting under nonequilibrium conditions.

We report a detailed account of the phase diagram of a recently introduced model for nonequilibrium wetting in (1+1) dimensions [H. Hinrichsen, R. Livi, D. Mukamel, and A. Politi, Phys. Rev. Lett. 79, 2710 (1997)]. A mean-field approximation is shown to reproduce the main features of the phase diagram, while providing indications for the behavior of the wetting transition in higher dimensions. The mean-field phase diagram is found to exhibit an extra transition line which does not exist in (1+1) dimensions. The line separates a phase in which the interface height distribution decays exponentially at large heights from a superexponentially decaying phase. Implications to wetting in dimensions higher than (1+1) are discussed.

Relationship between directed percolation and the synchronization transition in spatially extended systems.

We study the nature of the synchronization transition in spatially extended systems by discussing a simple stochastic model. An analytic argument is put forward showing that, in the limit of discontinuous processes, the transition belongs to the directed percolation (DP) universality class. The analysis is complemented by a detailed investigation of the dependence of the first passage time for the amplitude of the difference field on the adopted threshold. We find the existence of a critical threshold separating the regime controlled by linear mechanisms from that controlled by collective phenomena. As a result of this analysis, we conclude that the synchronization transition belongs to the DP class also in continuous models. The conclusions are supported by numerical checks on coupled map lattices too.

From multiplicative noise to directed percolation in wetting transitions.

A simple one-dimensional microscopic model of the depinning transition of an interface from an attractive hard wall is introduced and investigated. Upon varying a control parameter, the critical behavior observed along the transition line changes from a directed-percolation type to a multiplicative-noise type. Numerical simulations allow for a quantitative study of the multicritical point separating the two regions. Mean-field arguments and the mapping on yet a simpler model provide some further insight on the overall scenario.

Hemispheric predominance of abnormal findings in electroencephalogram (EEG).

The EEGs of 13,560 patients have been reviewed in order to determine whether abnormal findings, epileptiform or not, have a hemispheric dominance. We have included outpatients and hospitalized patients as well. Eight hundred and thirty-five EEGs had generalized abnormal findings, and 414 EEGs had lateralized abnormal findings. The EEGs of 322 patients (77.7%) had a left predominance, and those of 92 patients (22.3%) had a right predominance, of abnormal findings. A strong left predominance has been noted for the epileptiform discharges, i.e. 128 (79%) vs. 34 (21%). These results raise the possibility that the left hemisphere may be more vulnerable to nosological processes.

Colorectal endometriosis: aggressive surgical management and practical considerations in a patient with advanced disease.

The aim of this study was to evaluate the results of bowel resection in a patient with obstructive colorectal endometriosis. The presentation will acquaint the physician with the signs and symptoms, evaluation, and surgical treatment of colorectal endometriosis. We emphasize that our findings strongly support an aggressive surgical approach with resection for all visible cases of colorectal endometriosis in women with advanced disease.

Synthesis and preliminary biological characterization of a new potential (125)I-radioligand for dopamine and serotonin receptors.

The synthesis and a preliminary biological characterization of a new class of N-benzyl-aminoalcohols which have serotonin (5-HT(2)) and dopamine (D(2)) receptor affinity is described. In vitro competition binding studies were conducted with the new molecules and (3)H-spiperone on crude membrane preparation from rat striatum and frontal cortex. One of these compounds, 3-benzylamino-1-(4-fluoro-2-iodophenyl)-propan-1-ol (6f), whose IC(50) values are in the micromolar range for both the D(2) and 5-HT(2) receptors, was prepared in iodine-125 labelled form (6i) by nucleophilic substitution of the bromine atom of 3-benzylamino-1-(2-bromo-4-fluorophenyl)-propan-1-ol (6d). In the in vivo studies, conducted on rats, the radiolabelled molecule 6i shows a good capacity to cross the blood-brain barrier (BBB) with a mean value of first pass cerebral extraction (E) of ca. 50% when the regional cerebral blood flow, measured with microsphere technique, is in the experimental animal's physiologic range (0.8-1 mL/min/g). A preliminary in vitro autoradiographic distribution on coronal rat brain slices of the radioiodinated molecule showed that it was preferentially localized in the striatum and in the cerebral regions rich in dopamine- and serotonin receptors, even if a high non-specific binding was observed.