Non-adiabatic direct quantum dynamics using force fields: Toward solvation.

Quantum dynamics simulations are becoming a powerful tool for understanding photo-excited molecules. Their poor scaling, however, means that it is hard to study molecules with more than a few atoms accurately, and a major challenge at the moment is the inclusion of the molecular environment. Here, we present a proof of principle for a way to break the two bottlenecks preventing large but accurate simulations. First, the problem of providing the potential energy surfaces for a general system is addressed by parameterizing a standard force field to reproduce the potential surfaces of the molecule's excited-states, including the all-important vibronic coupling. While not shown here, this would trivially enable the use of an explicit solvent. Second, to help the scaling of the nuclear dynamics propagation, a hierarchy of approximations is introduced to the variational multi-configurational Gaussian method that retains the variational quantum wavepacket description of the key quantum degrees of freedom and uses classical trajectories for the remaining in a quantum mechanics/molecular mechanics like approach. The method is referred to as force field quantum dynamics (FF-QD), and a two-state ππ*/nπ* model of uracil, excited to its lowest bright ππ* state, is used as a test case.

Modifications of lung microbiota structure in traumatic brain injury ventilated patients according to time and enteral feeding formulas: a prospective randomized study.

BACKGROUND: Specialized diets enriched with immune nutrients could be an important supplement in patients (pts) with acute traumatic brain injury (TBI). Omega-3 and arginine may interact with immune response and microbiota. No data are available about the role of the specialized diets in modulating the lung microbiota, and little is known about the influence of lung microbiota structure in development of ventilator-associated pneumonia (VAP) in TBI pts. The aims of this study are to evaluate the impact of specific nutrients on the lung microbiota and the variation of lung microbiota in TBI pts developing VAP. METHODS: A cohort of 31 TBI pts requiring mechanical ventilation in ICU was randomized for treatment with specialized (16pts) or standard nutrition (15pts). Alpha and beta diversity of lung microbiota were analyzed from bronco Alveolar Lavage (BAL) samples collected at admission and 7 days post-ICU admission in both groups. A further analysis was carried out on the same samples retrospectively grouped in VAP or no VAP pts. RESULTS: None developed VAP in the first week. Thereafter, ten out of thirty-one pts developed VAP. The BAL microbiota on VAP group showed significant differences in beta diversity and Staphylococcus and Acinetobacter Genera were high. The specialized nutrition had influence on beta diversity that reached statistical significance only in Bray-Curtis distance. CONCLUSION: Our data suggest that TBI patients who developed VAP during ICU stay have different structures of BAL microbiota either at admission and at 7 days post-ICU admission, while no correlation has been observed between different enteral formulas and microbiota composition in terms of richness and evenness. These findings suggest that targeting the lung microbiota may be a promising approach for preventing infections in critically ill patients.

Optical absorption and magnetic circular dichroism spectra of thiouracils: a quantum mechanical study in solution.

The excited electronic states of 2-thiouracil, 4-thiouracil and 2,4-dithiouracil, the analogues of uracil where the carbonyl oxygens are substituted by sulphur atoms, have been investigated by computing the magnetic circular dichroism (MCD) and one-photon absorption (OPA) spectra at the time-dependent density functional theory level. Special attention has been paid to solvent effects, included by a mixed discrete/continuum model, and to determining how our results depend on the adopted DFT functional (CAM-B3LYP and B3LYP). Whereas including solvent effects does not dramatically impact the MCD and OPA spectra, though improving the agreement with the experimental spectra, the performances of CAM-B3LYP and B3LYP are remarkably different. CAM-B3LYP captures well the effect of thionation on the uracil excited states and provides spectra in good agreement with the experiments, whereas B3LYP shows some deficiency in describing 2-TU and 2,4-DTU spectra, despite being more accurate than CAM-B3LYP for 4-TU.

Ultra-thin resin embedding method for scanning electron microscopy of individual cells on high and low aspect ratio 3D nanostructures.

The preparation of biological cells for either scanning or transmission electron microscopy requires a complex process of fixation, dehydration and drying. Critical point drying is commonly used for samples investigated with a scanning electron beam, whereas resin-infiltration is typically used for transmission electron microscopy. Critical point drying may cause cracks at the cellular surface and a sponge-like morphology of nondistinguishable intracellular compartments. Resin-infiltrated biological samples result in a solid block of resin, which can be further processed by mechanical sectioning, however that does not allow a top view examination of small cell-cell and cell-surface contacts. Here, we propose a method for removing resin excess on biological samples before effective polymerization. In this way the cells result to be embedded in an ultra-thin layer of epoxy resin. This novel method highlights in contrast to standard methods the imaging of individual cells not only on nanostructured planar surfaces but also on topologically challenging substrates with high aspect ratio three-dimensional features by scanning electron microscopy.

Positive outcome of occlusal freeway space reestablishment in patients with medication overuse due to chronic migraine.

Considering the great chapter of migraines, it is important to note the signs and symptoms caused by an alteration of the relationship of the facial musculature and the occlusal freeway space (FWS) that is the distance from maximal intercuspation to the habitual rest position (measurable in 1.4-2.5 mm). To any mandible position changing (detected by periodontal, muscle and joint proprioceptors), there is an influence on the neuromuscular system and then an alteration of the FWS. A group of 60 patients with chronic migraine (CM) underwent a withdrawal of overused medication and were subjected to electromyographic and kinesiographic evaluation. All those who presented an alteration of the FWS at rest position have been subjected to treatment with orthosis device for about 12 months. The aim of our work is to obtain and define a correct mandibular position, physiological, in agreement with the neuromuscular structures of the patient. Clinical results obtained on this pool of patients, in terms of reduction of the VAS, let us understand the importance of the inviolability of the FWS and to eliminate any type of mandibular deviation with respect to the closure trajectory induced by TENS in patients suffering from CM.

Towards the realization of label-free biosensors through impedance spectroscopy integrated with IDES technology.

Impedance spectroscopy (IS) is a powerful technique for analysis of the complex electrical impedance of a large variety of biological systems, because it is sensitive both to surface phenomena and to changes of bulk properties. A simple and convenient method of analysis of cell properties by IS is described. An interdigitated electrodes configuration was used for the measurements; human epithelial cells were grown on the device to investigate the complex dielectric response as a function of frequency, in order to test the suitability of the device for use as a label-free biosensor. To test the ability of the device to detect channels in the cell membrane, the effect of drugs known to affect membrane integrity was also investigated. The frequency response of the admittance (i.e. the reciprocal of the impedance) can be well fitted by a model based on very simple assumptions about the cells coating the device surface and the current flow; from the calculations, membrane-specific capacitance and information about cell adhesion can be inferred. These preliminary efforts have shown that our configuration could lead to a label-free non-invasive technique for biosensing and cellular behavior monitoring which might prove useful in investigation of the basic properties of cells and the effect of drugs by estimation of some fundamental properties and modification of the electrical characteristics of the device.

Implementing gnathological and neuromuscular concepts in patients with chronic migraine.

Temporomandibular disorders are among the potential comorbidities of migraine, and recent reports showed that they may have a role in promoting its progression into chronic migraine (CM). In order to clarify the possible role of neuromuscular components of the stomatognathic system in patients with CM, we studied 18 patients admitted as inpatients at our Headache Unit to undergo a withdrawal protocol for medication overuse, who underwent orthosis, after clinical and instrumental gnathological evaluation. They were subsequently evaluated after 6 months. The values of electromyographic parameters as well as of pain outcomes showed a significant decrease after orthosis. The implementation of gnathological and neuromuscular concepts can have a relevant role in the management of CM patients, in the contest of a multidisciplinary approach.

Four-year clinical and neuroradiological follow-up of a papillary tumor of the pineal region.

Papillary tumor of the pineal region (PTPR) is a rare variety of CNS neoplasms and, since its first definition in 2003, only 64 cases have been described. PTPR is a primary neoplasm morphologically characterized by papillary structure staining for cytokeratin, transthyretin, neurone-specific enolase and S-100 protein. We report on a case of about 4 years' clinical history and neuroradiological follow-up of PTPR, in a 47-year-old Indian patient, with the aim of increasing the knowledge of its natural history. We describe through CT and MRI scans the natural evolution of this neoplasm, enhancing changes and morphologic structures involved, together with the final surgical treatment and pathological details. A mean growth rate average was calculated for this kind of lesion. In conclusion, the inexorable progressive growing nature of this tumor leads us to advocate an aggressive attitude among neurosurgeons and radiotherapists, with a precocious surgical approach when the suspicion rises.

Combined treatment of odontogenic keratocysts: initial marsupialization and successive enucleation with peripheral ostectomy plus Carnoy's solution application. A five-year follow-up experience.

AIM: The odontogenic keratocyst (KCOT) is a locally aggressive, cystic jaw lesion with a high growth potential and a propensity for recurrence. Considering its neoplastic features, treatments of keratocysts are required and they are generally classified as conservative or aggressive. However, although in literature there are several studies, the choice of treatment strategies remains controversial. We report a two-stage protocol based on initial marsupialization and successive enucleation. METHODS: Three cases of large KCOTs have been treated by initial marsupialization and, after a mean period of six months, successive enucleation with peripheral ostectomy and application of Carnoy's solution was performed. RESULTS: All patients were instructed in daily irrigation using chlorhexidine 0.2% during the period of marsupialization. After enucleation, good healing was obtained in all cases and from two up to five years of follow-up, there is no evidence of recurrence. CONCLUSION: Two-stage surgical treatment protocol of keratocyst leads to complete healing, preservation of important anatomical structures and absence of recurrence.

Use of fresh frozen bone graft in rehabilitation of maxillar atrophy.

AIM: Fresh frozen bone (FFB) is homologous bone obtained from human donors, provided by Tissue Banks. It is a graft material in reconstructive surgery; it is currently and widely used in orthopedic surgery and lately it has been introduced in oral and maxillofacial surgery. The purpose of this work was to show the use of fresh frozen homologous bone for bony augmentation of the maxilla and mandible in preparation for dental reconstruction with endosseous implants, as an effective alternative to harvesting and grafting autogenous bone from intra- or extra-oral donor sites. METHODS: The case presented clinically demonstrates the use of FFB grafts in the vertical augmentation of a severe maxillary atrophy in general anesthesia, and the outpatient treatment with implants insertion and prosthetic restoration. Histologic evaluation of graft biopsy six months after surgery is added to clinical assessments. RESULTS: Clinical outcome is shown with good volumetric and morphological reconstruction of the alveolar ridge without the need of a donor site. Excellent graft integration and bleeding newly formed bone was seen at the second surgical step (six months after FFB grafting), when fixation screws were removed and implant placement procedure was performed. CONCLUSION: The use of FFB in major preprosthetic surgery may be an acceptable therapeutic alternative to the autogenous block graft (harvested from iliac crest or calvarium) for its success rate as graft material. Benefits include: surgical procedure with reduced discomfort and infection risk as a second operation field to harvest the graft is avoided; FFB is safe, cheap and available in programmed amounts, its use can significantly reduce operating time.

Suppression of CCR5- but not CXCR4-tropic HIV-1 in lymphoid tissue by human herpesvirus 6.

HIV-1 infects target cells via a receptor complex formed by CD4 and a chemokine receptor, primarily CCR5 or CXCR4 (ref. 1). Commonly, HIV-1 transmission is mediated by CCR5-tropic variants, also designated slow/low, non-syncytia-inducer or macrophage-tropic, which dominate the early stages of HIV-1 infection and frequently persist during the entire course of the disease. In contrast, HIV-1 variants that use CXCR4 are typically detected at the later stages, and are associated with a rapid decline in CD4+ T cells and progression to AIDS (refs. 2,7-11). Disease progression is also associated with the emergence of concurrent infections that may affect the course of HIV disease by unknown mechanisms. A lymphotropic agent frequently reactivated in HIV-infected patients is human herpesvirus 6 (HHV-6), which has been proposed as a cofactor in AIDS progression. Here we show that in human lymphoid tissue ex vivo, HHV-6 affects HIV-1 infection in a coreceptor-dependent manner, suppressing CCR5-tropic but not CXCR4-tropic HIV-1 replication, as shown with both uncloned viral isolates and isogenic molecular chimeras. Furthermore, we demonstrate that HHV-6 increases the production of the CCR5 ligand RANTES ('regulated upon activation, normal T-cell expressed and secreted'), the most potent HIV-inhibitory CC chemokine, and that exogenous RANTES mimics the effects of HHV-6 on HIV-1, providing a mechanism for the selective blockade of CCR5-tropic HIV-1. Our data suggest that HHV-6 may profoundly influence the course of HIV-1 infection.

Chronic daily headache: suggestion for the neuromuscular oral therapy.

Tweny patients (M: 4, F: 16, mean age 37 ± 11 years) with diagnosis of chronic daily headache (CDH), after drug withdrawal, were under electromyography, kinesiography and masticatory muscle deprogramming by TENS to identify the physiological rest position of the mandible. Our purpose was to clarify a possible role of the neuromuscular stomatognathic system. Examinations showed that 17 patients needed a neuromuscular orthosis, an occlusal device, to provisionally correct the detected discrepancies of jaw position. Of those, the 10 patients who showed an occlusal sagittal discrepancy higher than 2 mm and/or a lateral deviation higher than 0.4 mm, associated with more than three parafunctional activities, had a meaningful decrease on frequency/intensity of migraine crisis and/or of days of headache. VAS pain score during crisis decreased from 9.0 ± 0.9 to 4.9 ± 2.7; frequency of crisis were from 20.7 ± 5.2 to 9.5 ± 7.7. Baseline pain were from 5.3 ± 1.2 to 3.0 ± 1.3. Satisfying clinical results can be reached combining behavioural education and neuromuscular orthosis. This can be very helpful in patients who show significant discrepancy of jaw position that only TENS deprogramming can reveal and kinesiography can detect with such accuracy.

Human herpesvirus 6 (HHV-6) causes severe thymocyte depletion in SCID-hu Thy/Liv mice.

Human herpesvirus 6 (HHV-6) is a potentially immunosuppressive agent that may act as a cofactor in the progression of AIDS. Here, we describe the first small animal model of HHV-6 infection. HHV-6 subgroup A, strain GS, efficiently infected the human thymic tissue implanted in SCID-hu Thy/Liv mice, leading to the destruction of the graft. Viral DNA was detected in Thy/Liv implants by quantitative polymerase chain reaction (PCR) as early as 4 d after inoculation and peaked at day 14. The productive nature of the infection was confirmed by electron microscopy and immunohistochemical staining. Atypical thymocytes with prominent nuclear inclusions were detected by histopathology. HHV-6 replication was associated with severe, progressive thymocyte depletion involving all major cellular subsets. However, intrathymic T progenitor cells (ITTPs) appeared to be more severely depleted than the other subpopulations, and a preferred tropism of HHV-6 for ITTPs was demonstrated by quantitative PCR on purified thymocyte subsets. These findings suggest that thymocyte depletion by HHV-6 may be due to infection and destruction of these immature T cell precursors. Similar results were obtained with strain PL-1, a primary isolate belonging to subgroup B. The severity of the lesions observed in this animal model underscores the possibility that HHV-6 may indeed be immunosuppressive in humans.

Persistent idiopathic facial pain: multidisciplinary approach and assumption of comorbidity.

Persistent idiopathic facial pain (PIFP) is a complex and uncertain nosographic entity, which has many aspects that need to be explored. The 21 patients selected (male 4 and female 17, mean age 40 years) were under electromyography (EMG) to determine the efficiency of the masseter muscles (MM) and the anterior temporalis muscles (TA), during activity and at rest, and under kinesiography (CMS) to identify the physiological rest position of the mandible after TENS stimulation. These patients were rehabilitated with a neuromuscular orthosis to provisionally correct the discrepancies identified. The EMG mean values of the muscles at rest were significantly above the normal (two-sample t test) for all four muscles and were normalized after the TENS session (Wilcoxon rank test). CMS showed that all 21 patients needed a mandibular advancement and 90.5% a correction in the frontal plane, obtained with orthosis. The comparison between the values of the maximal clench on natural dentition and on the orthosis showed a decrease in the asymmetry of muscular strength (-30.21% for TA and -55.81% for MM; Wilcoxon rank test) and a net increase of the strength expressed (LTA +25.37; LMM +59.40%, RMM +40.80%, RTA +30.27; Wilcoxon rank test; sign test). Preliminary results show a net decrease also in VAS pain score with a mean shift from 9.5 to 3.1. The results suggest a role for the neuromuscular component of the craniomandibular system in the pathogenesis of chronic idiopathic facial pain. All patients with PIFP should undergo the CMS-EMg examination.

Excited states decay of the A-T DNA: A PCM/TD-DFT study in aqueous solution of the (9-methyl-adenine)(2).(1-methyl-thymine)(2) stacked tetramer.

By exploiting some of the most recent advances in the quantum mechanical methods, we have been able to analyze the behavior of the lowest energy excited states of A-T B-DNA using a realistic model, namely a double strand tetramer formed by two thymine-adenine stacked pairs in aqueous solution. The equilibrium structure of the lowest energy bright and dark excited states has been determined and their main properties disclosed. On this ground, our study provides a detailed atomistic picture of the excited state decay and of the emission process, and it highlights the specific roles of base stacking and pairing. While absorption involves excited states delocalized over different stacked bases, emission mainly takes place from individual monomers and it is dominated by thymine bases. We show that fast "monomer-like" excited state decay routes are operative also in the double strand. On the other hand, the long living components of the excited state population of (dA).(dT) oligomers correspond to a dark excimer produced by intermonomer charge transfer between two stacked adenine bases, whereas adenine-thymine proton transfer plays a minor role in the excited state decay.

Differentiated microdomains of the luminal plasmalemma of murine muscle capillaries: segmental variations in young and old animals.

We investigated the luminal surface of the continuous endothelium of the microvasculature of the murine heart and diaphragm to find out whether it has differentiated microdomains. The probes were ferritin molecules, cationized to pI's 6.8, 7.15, 7.6, 8.0 and 8.4, which were introduced by retrograde or anterograde perfusion through the aorta or vena cava after the blood was removed from the vasculature. The pattern of labeling was analyzed by electron microscopy and assessed quantitatively by morphometry in arterioles, capillaries, and venules identified in bipolar microvascular fields in the diaphragm. The results showed that the plasmalemma proper was heavily but discontinuously labeled by all cationized ferritins (CF) used, the labeling being less extensive on the venular endothelium. CF had access as individual molecules to a fraction of the vesicular population opened on the luminal front of the endothelium. Plasmalemmal vesicle labeling increased from approximately 10 to approximately 25% as the pI decreased from 8.4 to 6.8. Vesicle labeling also increased with CF concentration in the perfusate. All CF binding sites were removed by pronase and papain. Heparinase and heparitinase caused only a slight reduction in CF labeling. Neuraminidase decreased the extent and density of labeling, especially on the plasmalemma proper of the venular endothelium; this decrease was particularly pronounced in old animals.

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.

Type-3 metabotropic glutamate receptors negatively modulate bone morphogenetic protein receptor signaling and support the tumourigenic potential of glioma-initiating cells.

Targeted-therapies enhancing differentiation of glioma-initiating cells (GICs) are potential innovative approaches to the treatment of malignant gliomas. These cells support tumour growth and recurrence and are resistant to radiotherapy and chemotherapy. We have found that GICs express mGlu3 metabotropic glutamate receptors. Activation of these receptors sustained the undifferentiated state of GICs in culture by negatively modulating the action of bone morphogenetic proteins, which physiologically signal through the phosphorylation of the transcription factors, Smads. The cross-talk between mGlu3 receptors and BMP receptors was mediated by the activation of the mitogen-activated protein kinase pathway. Remarkably, pharmacological blockade of mGlu3 receptors stimulated the differentiation of cultured GICs into astrocytes, an effect that appeared to be long lasting, independent of the growth conditions, and irreversible. In in vivo experiments, a 3-month treatment with the brain-permeant mGlu receptor antagonist, LY341495 limited the growth of infiltrating brain tumours originating from GICs implanted into the brain parenchyma of nude mice. While clusters of tumour cells were consistently found in the brain of control mice, they were virtually absent in a large proportion of mice treated with LY341495. These findings pave the way to a new non-cytotoxic treatment of malignant gliomas based on the use of mGlu3 receptor antagonists.

Bioelectronics goes 3D: new trends in cell-chip interface engineering.

Bioelectronic platforms can be used for electrophysiology, monitoring and stimulating specific cellular functions. While planar electroactive materials have been extensively used, in the past decade new approaches have focused on engineering the interface with pseudo-3D micro and nanostructures and, more recently, on 3D geometries (i.e. scaffold-like). Here, we present an overview of this transition from 2D to 3D bioelectronic platforms and our recent achievements of characterizing the interface between the cells and the device.