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Transient [3,3] Cope rearrangement of 3,3-dicyano-1,5-dienes: computational analysis and 2-step synthesis of arylcycloheptanes.
A simple and modular route to arylcycloheptene scaffolds is reported. The two-step route from Knoevenagel adducts and allylic electrophiles is made possible through the design of a Cope rearrangement that utilizes a "traceless" activating group to promote an otherwise thermodynamically unfavorable transformation. Experimentally, the [3,3] rearrangement occurrs transiently at room temperature with a computed barrier of 19.5 kcal mol-1, which ultimately allows for three-component bis-allylation. Ring-closing metathesis delivers the arylcycloheptane and removes the activating group. This report describes the design and optimization of the methodology, scope and mechanistic studies, and computational analysis
Osteoid osteoma of the femoral head treated by radiofrequency ablation: a case report
<p>Abstract</p> <p>Introduction</p> <p>We present a case report highlighting the unusual location and atypical imaging characteristics of an osteoid osteoma in the juxta-articular region of the femoral head, and treatment of the condition with radiofrequency ablation. This treatment option is low in both risk and morbidity and is therefore the best option in lesions that are difficult to access surgically because of the risks involved.</p> <p>Case presentation</p> <p>A 40-year-old Indian man from West Bengal presented to our facility with a history of progressively severe left hip pain of insidious onset, requiring analgesics. Imaging with plain radiographs, computed tomography and magnetic resonance imaging confirmed findings of osteoid osteoma in a subarticular location in the femoral head, although imaging features were atypical due to the intra-articular subchondral location.</p> <p>Conclusion</p> <p>Radiofrequency ablation is a newer treatment modality for osteoid osteoma that, being minimally invasive, offers comparable results to surgery with a significantly lower morbidity. To the best of our knowledge, treatment of osteoid osteoma in the foveal region of the femoral head with radiofrequency ablation has not been reported to date. We wish to highlight the successful outcome in our index case using this technique.</p
Pentastatin-1, a collagen IV derived 20-mer peptide, suppresses tumor growth in a small cell lung cancer xenograft model
<p>Abstract</p> <p>Background</p> <p>Angiogenesis is the formation of neovasculature from a pre-existing vascular network. Progression of solid tumors including lung cancer is angiogenesis-dependent. We previously introduced a bioinformatics-based methodology to identify endogenous anti-angiogenic peptide sequences, and validated these predictions <it>in vitro </it>in human umbilical vein endothelial cell (HUVEC) proliferation and migration assays.</p> <p>Methods</p> <p>One family of peptides with high activity is derived from the α-fibrils of type IV collagen. Based on the results from the <it>in vitro </it>screening, we have evaluated the ability of a 20 amino acid peptide derived from the α5 fibril of type IV collagen, pentastatin-1, to suppress vessel growth in an angioreactor-based directed <it>in vivo </it>angiogenesis assay (DIVAA). In addition, pentastatin-1 suppressed tumor growth with intraperitoneal peptide administration in a small cell lung cancer (SCLC) xenograft model in nude mice using the NCI-H82 human cancer cell line.</p> <p>Results</p> <p>Pentastatin-1 decreased the invasion of vessels into angioreactors <it>in vivo </it>in a dose dependent manner. The peptide also decreased the rate of tumor growth and microvascular density <it>in vivo </it>in a small cell lung cancer xenograft model.</p> <p>Conclusions</p> <p>The peptide treatment significantly decreased the invasion of microvessels in angioreactors and the rate of tumor growth in the xenograft model, indicating potential treatment for angiogenesis-dependent disease, and for translational development as a therapeutic agent for lung cancer.</p
Impaired expression of mitochondrial and adipogenic genes in adipose tissue from a patient with acquired partial lipodystrophy (Barraquer-Simons syndrome): a case report
<p>Abstract</p> <p>Introduction</p> <p>Acquired partial lipodystrophy or Barraquer-Simons syndrome is a rare form of progressive lipodystrophy. The etiopathogenesis of adipose tissue atrophy in these patients is unknown.</p> <p>Case presentation</p> <p>This is a case report of a 44-year-old woman with acquired partial lipodystrophy. To obtain insight into the molecular basis of lipoatrophy in acquired partial lipodystrophy, we examined gene expression in adipose tissue from this patient newly diagnosed with acquired partial lipodystrophy. A biopsy of subcutaneous adipose tissue was obtained from the patient, and DNA and RNA were extracted in order to evaluate mitochondrial DNA abundance and mRNA expression levels.</p> <p>Conclusion</p> <p>The expression of marker genes of adipogenesis and adipocyte metabolism, including the master regulator <it>PPARγ</it>, was down-regulated in subcutaneous adipose tissue from this patient. Adiponectin mRNA expression was also reduced but leptin mRNA levels were unaltered. Markers of local inflammatory status were unaltered. Expression of genes related to mitochondrial function was reduced despite unaltered levels of mitochondrial DNA. It is concluded that adipogenic and mitochondrial gene expression is impaired in adipose tissue in this patient with acquired partial lipodystrophy.</p
Head and Neck Lymphomas: Tip of the Iceberg?
ABSTRACT Background: Lymphomas comprise around 5% of all head and neck neoplasms and is the second most common extra nodal non hodgkin's lymphoma (NHL). However there is sporadic data on this entity from the subcontinent and hence we undertook this study. Methodology: This retrospective observational study was conducted at a tertiary care oncology center in India on diagnosed cases of NHL between January 2007 and December 2013. All patients were diagnosed based on histopathology and immunohistochemistry. Staging work up was done in all patients. Patients were considered as primary Head and Neck lymphomas if there was head and neck as the predominant site with or without regional lymph node involvement. Results: A total of 39 patients were studied. The age at presentation ranged from 29 to 78 years. The most common site of presentation was oral cavity (26%; n=10), followed by parotid and thyroid (18% each; n=7), eye (12%, n=5), maxilla (8%; n=3), paranasal sinuses (8%; n-=3) cheek (8%, n=3), and nasal cavity (2%, n=1). 41% (n=16) cases were in stage I, 43% (n=17) in stage II, 3% (n=1) in stage III, and 13% (n=5) were in stage IV. Most common histology was DLBCL (71%; n=28), followed by plasmablastic (10%; n=4), marginal zone (8%, n=3), mantle cell (3%; n=1), follicular lymphomas (5%; n=2), and NK/T cell lymphoma (3%; n=1). Most of the patients were of low risk (67%; n=26), followed by intermediate (23%; n=9), and high risk (10%; n=4). Patients were treated with anthracycline based chemotherapy +/-radiotherapy. In this study, stage I and stage II patients had a better prognosis and overall survival, median OS 28 months and 11 months, respectively. In stage III and IV, it was 7 and 3 months, respectively. According to site, the best median overall survival was seen with parotid (27 m), paranasal sinus (26m), and oral cavity (23 m), followed by thyroid (18 m) nasal cavity (17 m), maxilla (11 m), eye (8 m), and cheek (7 m)
Semi-natural habitats support biological control, pollination and soil conservation in Europe:A review
Semi-natural habitats are integral to most agricultural areas and have the potential to support ecosystem services, especially biological control and pollination by supplying resources for the invertebrates providing these services and for soil conservation by preventing erosion and run-off. Some habitats are supported through agri-environment scheme funding in the European Union, but their value for ecosystem service delivery has been questioned. An improved understanding of previous research approaches and outcomes will contribute to the development of more sustainable farming systems, improve experimental designs and highlight knowledge gaps especially for funders and researchers. Here we compiled a systematic map to allow for the first time a review of the quantity of evidence collected in Europe that semi-natural habitats support biological control, pollination and soil conservation. A literature search selected 2252 publications, and, following review, 270 met the inclusion criteria and were entered into the database. Most publications were of pest control (143 publications) with less on pollination (78 publications) or soil-related aspects (31). For pest control and pollination, most publications reported a positive effect of semi-natural habitats. There were weaknesses in the evidence base though because of bias in study location and the crops, whilst metrics (e.g. yield) valued by end users were seldom measured. Hedgerows, woodland and grassland were the most heavily investigated semi-natural habitats, and the wider landscape composition was often considered. Study designs varied considerably yet only 24% included controls or involved manipulation of semi-natural habitats. Service providers were commonly measured and used as a surrogate for ecosystem service delivery. Key messages for policymakers and funders are that they should encourage research that includes more metrics required by end users, be prepared to fund longer-term studies (61% were of only 1-year duration) and investigate the role of soils within semi-natural habitats in delivering ecosystem services
Repetition Enhancement for Frequency-Modulated but Not Unmodulated Sounds: A Human MEG Study
BACKGROUND: Decoding of frequency-modulated (FM) sounds is essential for phoneme identification. This study investigates selectivity to FM direction in the human auditory system. METHODOLOGY/PRINCIPAL FINDINGS: Magnetoencephalography was recorded in 10 adults during a two-tone adaptation paradigm with a 200-ms interstimulus-interval. Stimuli were pairs of either same or different frequency modulation direction. To control that FM repetition effects cannot be accounted for by their on- and offset properties, we additionally assessed responses to pairs of unmodulated tones with either same or different frequency composition. For the FM sweeps, N1m event-related magnetic field components were found at 103 and 130 ms after onset of the first (S1) and second stimulus (S2), respectively. This was followed by a sustained component starting at about 200 ms after S2. The sustained response was significantly stronger for stimulation with the same compared to different FM direction. This effect was not observed for the non-modulated control stimuli. CONCLUSIONS/SIGNIFICANCE: Low-level processing of FM sounds was characterized by repetition enhancement to stimulus pairs with same versus different FM directions. This effect was FM-specific; it did not occur for unmodulated tones. The present findings may reflect specific interactions between frequency separation and temporal distance in the processing of consecutive FM sweeps
Colorization and Automated Segmentation of Human T2 MR Brain Images for Characterization of Soft Tissues
Characterization of tissues like brain by using magnetic resonance (MR) images and colorization of the gray scale image has been reported in the literature, along with the advantages and drawbacks. Here, we present two independent methods; (i) a novel colorization method to underscore the variability in brain MR images, indicative of the underlying physical density of bio tissue, (ii) a segmentation method (both hard and soft segmentation) to characterize gray brain MR images. The segmented images are then transformed into color using the above-mentioned colorization method, yielding promising results for manual tracing. Our color transformation incorporates the voxel classification by matching the luminance of voxels of the source MR image and provided color image by measuring the distance between them. The segmentation method is based on single-phase clustering for 2D and 3D image segmentation with a new auto centroid selection method, which divides the image into three distinct regions (gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) using prior anatomical knowledge). Results have been successfully validated on human T2-weighted (T2) brain MR images. The proposed method can be potentially applied to gray-scale images from other imaging modalities, in bringing out additional diagnostic tissue information contained in the colorized image processing approach as described
High Rates of Hepatitis C Virus Reinfection and Spontaneous Clearance of Reinfection in People Who Inject Drugs: A Prospective Cohort Study
Hepatitis C virus reinfection and spontaneous clearance of reinfection were examined in a highly characterisedcohort of 188 people who inject drugs over a five-year period. Nine confirmed reinfections and 17 possiblereinfections were identified (confirmed reinfections were those genetically distinct from the previous infection andpossible reinfections were used to define instances where genetic differences between infections could not beassessed due to lack of availability of hepatitis C virus sequence data). The incidence of confirmed reinfection was28.8 per 100 person-years (PY), 95%CI: 15.0-55.4; the combined incidence of confirmed and possible reinfectionwas 24.6 per 100 PY (95%CI: 16.8-36.1). The hazard of hepatitis C reinfection was approximately double that ofprimary hepatitis C infection; it did not reach statistical significance in confirmed reinfections alone (hazard ratio [HR]:2.45, 95%CI: 0.87-6.86, p=0.089), but did in confirmed and possible hepatitis C reinfections combined (HR: 1.93,95%CI: 1.01-3.69, p=0.047) and after adjustment for the number of recent injecting partners and duration of injecting.In multivariable analysis, shorter duration of injection (HR: 0.91; 95%CI: 0.83-0.98; p=0.019) and multiple recentinjecting partners (HR: 3.12; 95%CI: 1.08-9.00, p=0.035) were independent predictors of possible and confirmedreinfection. Time to spontaneous clearance was shorter in confirmed reinfection (HR: 5.34, 95%CI: 1.67-17.03,p=0.005) and confirmed and possible reinfection (HR: 3.10, 95%CI: 1.10-8.76, p-value=0.033) than primary infection.Nonetheless, 50% of confirmed reinfections and 41% of confirmed or possible reinfections did not spontaneouslyclear.Conclusions: Hepatitis C reinfection and spontaneous clearance of hepatitis C reinfection were observed at highrates, suggesting partial acquired natural immunity to hepatitis C virus. Public health campaigns about the risks ofhepatitis C reinfection are required
Dimethyl Sulfoxide Induces Both Direct and Indirect Tau Hyperphosphorylation
Dimethyl sulfoxide (DMSO) is widely used as a solvent or vehicle for biological studies, and for treatment of specific disorders, including traumatic brain injury and several forms of amyloidosis. As Alzheimer’s disease (AD) brains are characterized by deposits of β-amyloid peptides, it has been suggested that DMSO could be used as a treatment for this devastating disease. AD brains are also characterized by aggregates of hyperphosphorylated tau protein, but the effect of DMSO on tau phosphorylation is unknown. We thus investigated the impact of DMSO on tau phosphorylation in vitro and in vivo. One hour following intraperitoneal administration of 1 or 2 ml/kg DMSO in mice, no change was observed in tau phosphorylation. However, at 4 ml/kg, tau was hyperphosphorylated at AT8 (Ser202/Thr205), PHF-1 (Ser396/Ser404) and AT180 (Thr231) epitopes. At this dose, we also noticed that the animals were hypothermic. When the mice were maintained normothermic, the effect of 4 ml/kg DMSO on tau hyperphosphorylation was prevented. On the other hand, in SH-SY5Y cells, 0.1% DMSO induced tau hyperphosphorylation at AT8 and AT180 phosphoepitopes in normothermic conditions. Globally, these findings demonstrate that DMSO can induce tau hyperphosphorylation indirectly via hypothermia in vivo, and directly in vitro. These data should caution researchers working with DMSO as it can induce artifactual results both in vivo and in vitro
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