Specific Involvement of Pilus Type 2a in Biofilm Formation in Group B Streptococcus

Streptococcus agalactiae is the primary colonizer of the anogenital mucosa of up to 30% of healthy women and can infect newborns during delivery and cause severe sepsis and meningitis. Persistent colonization usually involves the formation of biofilm and increasing evidences indicate that in pathogenic streptococci biofilm formation is mediated by pili. Recently, we have characterized pili distribution and conservation in 289 GBS clinical isolates and we have shown that GBS has three pilus types, 1, 2a and 2b encoded by three corresponding pilus islands, and that each strain carries one or two islands. Here we have investigated the capacity of these strains to form biofilms. We have found that most of the biofilm-formers carry pilus 2a, and using insertion and deletion mutants we have confirmed that pilus type 2a, but not pilus types 1 and 2b, confers biofilm-forming phenotype. We also show that deletion of the major ancillary protein of type 2a did not impair biofilm formation while the inactivation of the other ancillary protein and of the backbone protein completely abolished this phenotype. Furthermore, antibodies raised against pilus components inhibited bacterial adherence to solid surfaces, offering new strategies to prevent GBS infection by targeting bacteria during their initial attachment to host epithelial cells

Blocking the formation of radiation–induced breast cancer stem cells

The goal of adjuvant (post-surgery) radiation therapy (RT) for breast cancer (BC) is to eliminate residual cancer cells, leading to better local tumor control and thus improving patient survival. However, radioresistance increases the risk of tumor recurrence and negatively affects survival. Recent evidence shows that breast cancer stem cells (BCSCs) are radiation-resistant and that relatively differentiated BC cells can be reprogrammed into induced BCSCs (iBCSCs) via radiation-induced re-expression of the stemness genes. Here we show that in irradiation (IR)-treated mice bearing syngeneic mammary tumors, IR-induced stemness correlated with increased spontaneous lung metastasis (51.7%). However, IR-induced stemness was blocked by targeting the NF-κB- stemness gene pathway with disulfiram (DSF)and Copper (Cu2+). DSF is an inhibitor of aldehyde dehydrogenase (ALDH) and an FDA-approved drug for treating alcoholism. DSF binds to Cu2+ to form DSF-Cu complexes (DSF/Cu), which act as a potent apoptosis inducer and an effective proteasome inhibitor, which, in turn, inhibits NF-κB activation. Treatment of mice with RT and DSF significantly inhibited mammary primary tumor growth (79.4%) and spontaneous lung metastasis (89.6%) compared to vehicle treated mice. This anti-tumor efficacy was associated with decreased stem cell properties (or stemness) in tumors. We expect that these results will spark clinical investigation of RT and DSF as a novel combinatorial treatment for breast cancer

Riociguat treatment in patients with chronic thromboembolic pulmonary hypertension: Final safety data from the EXPERT registry

Objective: The soluble guanylate cyclase stimulator riociguat is approved for the treatment of adult patients with pulmonary arterial hypertension (PAH) and inoperable or persistent/recurrent chronic thromboembolic pulmonary hypertension (CTEPH) following Phase

Continuum Damage Progressive Failure Modeling for Crashworthiness and Static Analyses of Laminated Composites

Thesis (Ph.D.)--University of Washington, 2019A new energy-based composite continuum damage model is presented for laminated composite structures. The composite laminate is modelled at the meso-scale using the finite element method, specifically: shell elements. Each composite lamina is modelled with one or four integration points, depending on if reduced or full integration elements are used. Each lamina is modelled as a 2D plane stress orthotropic material and damage is included by degrading the stiffness matrix. Element deletion is used when all integration points have failed. The theory is developed to predict failure initiation using a modified version of the Hashin’s failure criteria, and failure growth is modelled using damage variables which are developed as part of this work. The theory has been written to be used for both static failure and dynamic crush analyses. Two sets of damage variables are derived, one for static analyses and a separate one for dynamic crush. When performing a dynamic crush analysis, the distributed damage model is utilized in order to ensure that the progressive failure crush mode correcty takes place. The damage model is energy-based using the fracture energies of four failure directions: the fiber and matrix directions, and in each of tension and compression. Mesh-size objectivity is assured via the adoption of the Crack Band Theory. The theory is implemented into an LS-DYNA user-defined material model (UMAT) in order to take advantage of the pre-built contact algorithms needed for crush analyses and for solving the governing equations of motion. The theory is applied to a static and crush problem, with excellent agreement between the experimental and numerical results for both cases. A tensile notched specimen is tested and simulated. Both the failure morphology and resulting load-displacement results at the constraint are found to match very well. A crush experiment carried out by the author is simulated. In addition to matching the experimental results with a high degree of accuracy, the theory discussed herein offers significant advantages over alternative damage models present in the literature. There is no need to filter the load – displacement results using a non-physical numerical scheme, and the high impulse loads are eliminated. In addition, the theory offers a level of robustness and stability which allows it to be used with any contact type, including ‘hard’ contact, and therefore eliminates the need to calibrate the penalty-based contact algorithm’s load penetration curve with non-physical stiffnesses

Neuropsychological profiles and outcomes in children with new onset frontal lobe epilepsy

Frontal lobe epilepsy (FLE) is the second most frequent type of localization-related epilepsy, and it may impact neurocognitive functioning with high variability. The prevalence of neurocognitive impairment in affected children remains poorly defined. This report outlines the neuropsychological profiles and outcomes in children with new onset FLE, and the impact of epilepsy-related factors, such as seizure frequency and antiepileptic drug (AED) load, on the neurocognitive development. Twenty-three consecutive children (15 males and 8 females) with newly diagnosed cryptogenic FLE were enrolled; median age at epilepsy onset was 7 years (6-9.6 years). They underwent clinical and laboratory evaluation and neuropsychological assessment before starting AED treatment (time 0) and after one year of treatment (time 1). Twenty age-matched patients affected by idiopathic generalized epilepsy (10 male and 10 females) and eighteen age-matched healthy subjects (9 males and 9 females) were enrolled as controls and underwent the same assessment. All patients with FLE showed a significant difference in almost all assessed cognitive domains compared with controls, mainly in frontal functions and memory. At time 1, patients were divided into two groups according to epilepsy-related factors: group 1 (9 patients) with persisting seizures despite AED polytherapy, and group 2 (14 patients) with good seizure control in monotherapy. A significant difference was highlighted in almost all subtests in group 1 compared with group 2, both at time 0 and at time 1. In children with FLE showing a broad range of neurocognitive impairments, the epilepsy-related factors mostly related to a worse neurocognitive outcome are poor seizure control and the use of AED polytherapy, suggesting that epileptic discharges may have a negative impact on the functioning of the involved cerebral regions

Tracking the Re-organization of Motor Functions After Disconnective Surgery: A Longitudinal fMRI and DTI Study

Objective: Mechanisms of motor plasticity are critical to maintain motor functions after cerebral damage. This study explores the mechanisms of motor reorganization occurring before and after surgery in four patients with drug-refractory epilepsy candidate to disconnective surgery. Methods: We studied four patients with early damage, who underwent tailored hemispheric surgery in adulthood, removing the cortical motor areas and disconnecting the corticospinal tract (CST) from the affected hemisphere. Motor functions were assessed clinically, with functional MRI (fMRI) tasks of arm and leg movement and Diffusion Tensor Imaging (DTI) before and after surgery with assessments of up to 3 years. Quantifications of fMRI motor activations and DTI fractional anisotropy (FA) color maps were performed to assess the lateralization of motor network. We hypothesized that lateralization of motor circuits assessed preoperatively with fMRI and DTI was useful to evaluate the motor outcome in these patients. Results: In two cases preoperative DTI-tractography did not reconstruct the CST, and FA-maps were strongly asymmetric. In the other two cases, the affected CST appeared reduced compared to the contralateral one, with modest asymmetry in the FA-maps. fMRI showed different degrees of lateralization of the motor network and the SMA of the intact hemisphere was mostly engaged in all cases. After surgery, patients with a strongly lateralized motor network showed a stable performance. By contrast, a patient with a more bilateral pattern showed worsening of the upper limb function. For all cases, fMRI activations shifted to the intact hemisphere. Structural alterations of motor circuits, observed with FA values, continued beyond 1 year after surgery. Conclusion: In our case series fMRI and DTI could track the longitudinal reorganization of motor functions. In these four patients the more the paretic limbs recruited the intact hemisphere in primary motor and associative areas, the greater the chances were of maintaining elementary motor functions after adult surgery. In particular, DTI-tractography and quantification of FA-maps were useful to assess the lateralization of motor network. In these cases reorganization of motor connectivity continued for long time periods after surgery

Table_1_Tracking the Re-organization of Motor Functions After Disconnective Surgery: A Longitudinal fMRI and DTI Study.DOC

<p>Objective: Mechanisms of motor plasticity are critical to maintain motor functions after cerebral damage. This study explores the mechanisms of motor reorganization occurring before and after surgery in four patients with drug-refractory epilepsy candidate to disconnective surgery.</p><p>Methods: We studied four patients with early damage, who underwent tailored hemispheric surgery in adulthood, removing the cortical motor areas and disconnecting the corticospinal tract (CST) from the affected hemisphere. Motor functions were assessed clinically, with functional MRI (fMRI) tasks of arm and leg movement and Diffusion Tensor Imaging (DTI) before and after surgery with assessments of up to 3 years. Quantifications of fMRI motor activations and DTI fractional anisotropy (FA) color maps were performed to assess the lateralization of motor network. We hypothesized that lateralization of motor circuits assessed preoperatively with fMRI and DTI was useful to evaluate the motor outcome in these patients.</p><p>Results: In two cases preoperative DTI-tractography did not reconstruct the CST, and FA-maps were strongly asymmetric. In the other two cases, the affected CST appeared reduced compared to the contralateral one, with modest asymmetry in the FA-maps. fMRI showed different degrees of lateralization of the motor network and the SMA of the intact hemisphere was mostly engaged in all cases. After surgery, patients with a strongly lateralized motor network showed a stable performance. By contrast, a patient with a more bilateral pattern showed worsening of the upper limb function. For all cases, fMRI activations shifted to the intact hemisphere. Structural alterations of motor circuits, observed with FA values, continued beyond 1 year after surgery.</p><p>Conclusion: In our case series fMRI and DTI could track the longitudinal reorganization of motor functions. In these four patients the more the paretic limbs recruited the intact hemisphere in primary motor and associative areas, the greater the chances were of maintaining elementary motor functions after adult surgery. In particular, DTI-tractography and quantification of FA-maps were useful to assess the lateralization of motor network. In these cases reorganization of motor connectivity continued for long time periods after surgery.</p

MRI in Late-Onset Rasmussen Encephalitis: A Long-Term Follow-Up Study

Late-onset Rasmussen encephalitis (LoRE) is a rare unihemispheric progressive inflammatory disorder causing neurological deficits and epilepsy. The long-term radiological evolution has never been fully described. We retrospectively analyzed the MR images of 13 LoRE patients from a total of 136 studies, and searched for focal areas of volume loss or signal intensity abnormality in grey matter or white matter. Each subject had a median of nine MRI studies (IQR 7&ndash;13). Frontal and temporal lobes were the most affected regions (13/13 and 8/13, respectively) and showed the greatest worsening over time in terms of atrophic changes (9/13 and 5/8, respectively). A milder cortical atrophy was found in the insular and parietal lobes. The caudate nucleus was affected in seven patients. Hyperintensities of grey matter and white matter on T2-WI and FLAIR images were observed in all patients, and transiently in eight patients. In two cases out of the latter patients, these transient alterations evolved into atrophy of the same region. Disease duration was significantly associated with signal abnormalities in the grey matter at last follow-up. LoRE MRI alterations are milder, and their progression is markedly slower compared to radiological findings described in the childhood form