233 research outputs found

    Craniopharyngioma in children: trends from a third consecutive single-center cohort study

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    OBJECTIVE: The management of children with craniopharyngioma has evolved over time, with a trend toward less invasive neurosurgical approaches as surgeons have sought to balance oncological control and treatment-related morbidity. To this end, the aim of this study was to evaluate the safety and effectiveness of the current management of children with craniopharyngioma compared to the previous management methods used at the authors’ treatment center. METHODS: A prospectively maintained database was searched over a 14-year period between January 1, 2005, and December 31, 2018, to identify all children 17 years of age or younger with a new diagnosis of craniopharyngioma. A retrospective case note review was performed for each child to extract data on the presentation, investigation, treatment, and outcome of their illness. Morbidity was assessed in the same fashion as in previous cohorts, according to the following categories: visual loss, pituitary dysfunction, hypothalamic dysfunction, neurological deficits, and cognitive impairment. RESULTS: In total, 59 children were identified with craniopharyngioma during the study period. A total of 92 operations were performed, including cyst drainage (35/92; 38.0%), craniotomy and resection (30/92; 32.6%), and transsphenoidal resection (16/92; 17.4%). Approximately two-thirds of all operations were performed using image guidance (66/92; 71.7%) and one-third were performed using endoscopy (27/92; 29.3%). The majority of children had adjuvant therapy comprising proton beam therapy (18/59; 30.5%) or conventional radiotherapy (16/59; 27.1%). The median follow-up duration was 44 months (range 1–142 months), and approximately one-half of the children had no evidence of residual disease on MRI studies (28/59; 47.5%). Of the remaining 31 children, there was a reduction in the volume of residual disease in 8 patients (8/59; 13.6%), stable residual disease in 18 (18/59; 30.5%), and tumor growth in 5 patients (5/59; 8.5%). There was significantly reduced morbidity (p < 0.05) in all categories in the current cohort compared with our last cohort (1996–2004). CONCLUSIONS: The authors’ institutional experience of pediatric craniopharyngioma confirms a trend toward less invasive neurosurgical procedures, most of which are now performed with the benefit of image guidance or endoscopy. Moreover, the authors have identified an expanding role for more targeted radiotherapy for children with residual disease. These advances have allowed for tumor control comparable to that achieved in previous cohorts, but with significantly reduced morbidity and mortality

    Fermi Surface Properties of Low Concentration Cex_{x}La1−x_{1-x}B6_{6}: dHvA

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    The de Haas-van Alphen effect is used to study angular dependent extremal areas of the Fermi Surfaces (FS) and effective masses of Cex_{x}La1−x_{1-x}B6% _{6} alloys for xx between 0 and 0.05. The FS of these alloys was previously observed to be spin polarized at low Ce concentration (xx = 0.05). This work gives the details of the initial development of the topology and spin polarization of the FS from that of unpolarized metallic LaB6_{6} to that of spin polarized heavy Fermion CeB6_{6} .Comment: 7 pages, 9 figures, submitted to PR

    Osthole: A Multifunctional Natural Compound with Potential Anticancer, Antioxidant and Anti-inflammatory Activities

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    Nature has always proved to be a significant reservoir of bioactive scaffolds that have been used for the discovery of drugs since times. Medicinal plants continue to be a solid niche for biologically active and therapeutically effective chemical entities, opening up new avenues for the successful treatment of several human diseases. The contribution of plant-derived compounds to drug discovery, either in their original or in the semi-synthetic derivative form, extends far back in time. This review aims to focus on the sources, biological, and pharmacological profile of a pharmacologically active plant-derived coumarin, osthole, which is an important component of numerous remedial plants such as Cnidium monnieri. Several studies have revealed that osthole possess pharmacological properties such as anticancer, antioxidant, anti-hyperglycemic, neuroprotective, and antiplatelet. Osthole has been reported to regulate various signaling pathways, which in turn modulate several apoptosis-related pro-teins, cell cycle regulators, protein kinases, transcriptional factors, cytokines, and growth receptors affiliated with inflammation, proliferation and several other ailments. Osthole is known to halt proliferation and metastasis of cancerous cells by arresting the cell cycle and inducing apoptosis. The data in this review paper supports the pharmacological potential of osthole but further experimentation, biosafety profiling and synergistic effects of this compound need to be focused by the researchers to understand the full spectrum of pharmacological potential of this therapeutically potent compound

    A systematic review of the evidence for single stage and two stage revision of infected knee replacement

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    BACKGROUND: Periprosthetic infection about the knee is a devastating complication that may affect between 1% and 5% of knee replacement. With over 79 000 knee replacements being implanted each year in the UK, periprosthetic infection (PJI) is set to become an important burden of disease and cost to the healthcare economy. One of the important controversies in treatment of PJI is whether a single stage revision operation is superior to a two-stage procedure. This study sought to systematically evaluate the published evidence to determine which technique had lowest reinfection rates. METHODS: A systematic review of the literature was undertaken using the MEDLINE and EMBASE databases with the aim to identify existing studies that present the outcomes of each surgical technique. Reinfection rate was the primary outcome measure. Studies of specific subsets of patients such as resistant organisms were excluded. RESULTS: 63 studies were identified that met the inclusion criteria. The majority of which (58) were reports of two-stage revision. Reinfection rated varied between 0% and 41% in two-stage studies, and 0% and 11% in single stage studies. No clinical trials were identified and the majority of studies were observational studies. CONCLUSIONS: Evidence for both one-stage and two-stage revision is largely of low quality. The evidence basis for two-stage revision is significantly larger, and further work into direct comparison between the two techniques should be undertaken as a priority

    Physcion and Physcion 8-O-β-D-glucopyranoside: Natural Anthraquinones with Potential Anti-cancer Activities.

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    Nature has provided prodigious reservoirs of pharmacologically active compounds for drug development since times. Physcion and physcion 8-O-β-D-glucopyranoside (PG) are bioactive natural anthraquinones which exert anti-inflammatory and anti-cancer properties with minimum or no adverse effects. Moreover, physcion also exhibits anti-microbial and hepatoprotective properties while PG is known to have anti-sepsis as well as ameliorative activities against dementia. This review aims to highlight the natural sources and anti-cancer activities of physcion and PG along with asso-ciated mechanisms of actions. On the basis of the literature, physcion and PG regulate multitudinous cell signaling path-ways through the modulation of various regulators of cell cycle, protein kinases, microRNAs, transcriptional factors, and apoptosis linked proteins resulting in the effective killing of cancerous cells in vitro as well as in vivo. Both compounds effectively suppress metastasis, furthermore, physcion acts as inhibitor of 6PGD and also play an important role in chemosensitization. This review article suggests that physcion and PG are potent anti-cancer drug candidates but further investigations on their mechanism of action and pre-clinical trials are mandatory in order to comprehend the full potential of these natural cancer killers in anti-cancer remedies

    A Superconducting Instability in the Infinite-U Anderson Lattice in the Presence of Crystal Electric Fields

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    We report evidence of a superconducting instability (of T1gT_{1g} symmetry) in the infinite-U Anderson lattice in the presence of crystal fields of cubic symmetry. We assume a lattice of 4f4f sites, each with a total angular momentum of J=5/2J=5/2 that is split by crystal fields into a low-lying doublet of Γ7\Gamma_7 symmetry and an excited quartet of Γ8\Gamma_8 symmetry. Slave Bosons on the 4f4f sites create and destroy 4f04f^0 configurations and Lagrange multipliers at each 4f4f site enforce the occupancy constraint due to the infinite Coulomb repulsion. Quasiparticle interactions are due to exchange of 4f4f density fluctuations, which are represented by fluctuations in the slave Bosons and Lagrange multipliers. We use the so-called analytic tetrahedron method to calculate the dressed (to order 1/N) Boson Green functions. In weak couping, the exchange of the dressed Bosons gives rise to a superconducting instability of T1gT_{1g}, xy(x2−y2)xy(x^2-y^2), symmetry. The A1gA_{1g}, ``s-wave'', channel has strongly repulsive interactions and hence no pairing instability. The T2gT_{2g} channel exhibits weakly repulsive interactions. Average quasiparticle interactions in the EgE_g, x2−y2x^2-y^2, 3z2−r23z^2-r^2, channel fluctuate strongly as a function of the number of tetrahedra used to calculate the Bosonic Green functions,Comment: 66 pages+ 17 postscript figures, LATE

    The prevalence of stillbirths: a systematic review

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    BACKGROUND: Stillbirth rate is an important indicator of access to and quality of antenatal and delivery care. Obtaining overall estimates across various regions of the world is not straightforward due to variation in definitions, data collection methods and reporting. METHODS: We conducted a systematic review of a range of pregnancy-related conditions including stillbirths and performed meta-analysis of the subset of studies reporting stillbirth rates. We examined variation across rates and used meta-regression techniques to explain observed variation. RESULTS: We identified 389 articles on stillbirth prevalence among the 2580 included in the systematic review. We included 70 providing 80 data sets from 50 countries in the meta-analysis. Pooled prevalence rates show variation across various subgroup categories. Rates per 100 births are higher in studies conducted in less developed country settings as compared to more developed (1.17 versus 0.50), of inadequate quality as compared to adequate (1.12 versus 0.66), using sub-national sample as compared to national (1.38 versus 0.68), reporting all stillbirths as compared to late stillbirths (0.95 versus 0.63), published in non-English as compared to English (0.91 versus 0.59) and as journal articles as compared to non-journal (1.37 versus 0.67). The results of the meta-regression show the significance of two predictor variables – development status of the setting and study quality – on stillbirth prevalence. CONCLUSION: Stillbirth prevalence at the community level is typically less than 1% in more developed parts of the world and could exceed 3% in less developed regions. Regular reviews of stillbirth rates in appropriately designed and reported studies are useful in monitoring the adequacy of care. Systematic reviews of prevalence studies are helpful in explaining sources of variation across rates. Exploring these methodological issues will lead to improved standards for assessing the burden of reproductive ill-health
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