165 research outputs found

    Serum Müllerian inhibiting substance levels are lower in premenopausal women with breast precancer and cancer

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    <p>Abstract</p> <p>Background</p> <p>In preclinical studies, müllerian inhibiting substance (MIS) has a protective affect against breast cancer. Our objective was to determine whether serum MIS concentrations were associated with cancerous or precancerous lesions. Blood from 30 premenopausal women was collected and serum extracted prior to their undergoing breast biopsy to assess a suspicious lesion found on imaging or physical examination. Based on biopsy results, the serum specimens were grouped as cancer (invasive or ductal carcinoma <it>in situ</it>), precancer (atypical hyperplasia or lobular carcinoma <it>in situ</it>), or benign.</p> <p>Findings</p> <p>Serum from women with cancer and precancer (p = .0009) had lower MIS levels than serum from women with benign disease.</p> <p>Conclusion</p> <p>Our findings provide preliminary evidence for MIS being associated with current breast cancer risk, which should be validated in a larger population.</p

    Tissue Harvester with Functional Valve (THFV): Shidham's device for reproducibly higher specimen yield by fine needle aspiration biopsy with easy to perform steps

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    BACKGROUND: Fine needle aspiration biopsy (FNAB) cytology has been a highly effective methodology for tissue diagnosis and for various ancillary studies including molecular tests. In addition to other benefits, FNAB predominantly retrieves the diagnostic loosely cohesive cells in the lesion as compared to the adjacent supporting stroma with relatively higher cohesiveness. However, FNAB procedure performed with currently available resources is highly skill dependent with inter-performer variability, which compromises its full potential as a diagnostic tool. In this study we report a device overcoming these limitations. METHODS: 'Tissue Harvester with Functional Valve' (THFV) was evaluated as part of a phase 1 National Institute of Health (NIH) research grant under Small Business Technology Transfer (STTR) Program. Working prototypes of the device were prepared. Each of the four cytopathologists with previous cytopathology fellowship training and experience in performing FNAB evaluated 5 THFV and 5 hypodermic needles resulting in 40 specimens (20 with THFV, 20 with hypodermic needles). A piece of fresh cattle liver stuffed in latex glove was used as the specimen. Based on these results a finished design was finalized. RESULTS: The smears and cell blocks prepared from the specimens obtained by THFV were superior in terms of cellularity to specimens obtained with hypodermic needles. The tissuecrit of specimens obtained with THFV ranged from 70 to 100 μl (mean 87, SD 10), compared to 17 to 30 μl (mean 24, SD 4) with conventional hypodermic needles (p < .0001, Student t-test). The technical ease [on a scale of 1 (easy) to 5 (difficult)] with THFV ranged from 1 to 2 as compared to 2 to 3 with hypodermic needles. CONCLUSION: The specimen yield with the new THFV was significantly higher when compared to hypodermic needles. Also, the FNAB procedure with THFV was relatively easier in comparison with hypodermic needles. The final version of Shidham's THFV device would improve the FNAB specimen yield by eliminating the skill factor. The increased specimen yield by this device would also facilitate wider application of FNAB specimens for various ancillary tests, including molecular tests

    Raman spectroscopy and advanced mathematical modelling in the discrimination of human thyroid cell lines

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    Raman spectroscopy could offer non-invasive, rapid and an objective nature to cancer diagnostics. However, much work in this field has focused on resolving differences between cancerous and non-cancerous tissues, and lacks the reproducibility and interpretation to be put into clinical practice. Much work is needed on basic cellular differences between malignancy and normal. This would allow the establishment of a clinically relevant cellular based model to translate to tissue classification. Raman spectroscopy provides a very detailed biochemical analysis of the target material and to 'unlock' this potential requires sophisticated mathematical modelling such as neural networks as an adjunct to data interpretation. Commercially obtained cancerous and non-cancerous cells, cultured in the laboratory were used in Raman spectral measurements. Data trends were visualised through PCA and then subjected to neural network analysis based on self-organising maps; consisting of m maps, where m is the number of classes to be recognised. Each map approximates the statistical distribution of a given class. The neural network analysis provided a 95% accuracy for identification of the cancerous cell line and 92% accuracy for normal cell line. In this preliminay study we have demonstrated th ability to distinguish between "normal" and cancerous commercial cell lines. This encourages future work to establish the reasons underpinning these spectral differences and to move forward to more complex systems involving tissues. We have also shown that the use of sophisticated mathematical modelling allows a high degree of discrimination of 'raw' spectral data

    Decorrelation and efficient coding by retinal ganglion cells

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    An influential theory of visual processing asserts that retinal center-surround receptive fields remove spatial correlations in the visual world, producing ganglion cell spike trains that are less redundant than the corresponding image pixels. For bright, high-contrast images, this decorrelation would enhance coding efficiency in optic nerve fibers of limited capacity. We tested the central prediction of the theory and found that the spike trains of retinal ganglion cells were indeed decorrelated compared with the visual input. However, most of the decorrelation was accomplished not by the receptive fields, but by nonlinear processing in the retina. We found that a steep response threshold enhanced efficient coding by noisy spike trains and that the effect of this nonlinearity was near optimal in both salamander and macaque retina. These results offer an explanation for the sparseness of retinal spike trains and highlight the importance of treating the full nonlinear character of neural codes

    Perceptions about hemodialysis and transplantation among African American adults with end-stage renal disease: inferences from focus groups

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    BACKGROUND: Disparities in access to kidney transplantation (KT) remain inadequately understood and addressed. Detailed descriptions of patient attitudes may provide insight into mechanisms of disparity. The aims of this study were to explore perceptions of dialysis and KT among African American adults undergoing hemodialysis, with particular attention to age- and sex-specific concerns. METHODS: Qualitative data on experiences with hemodialysis and views about KT were collected through four age- and sex-stratified (males <65, males ≥65, females <65, and females ≥65 years) focus group discussions with 36 African American adults recruited from seven urban dialysis centers in Baltimore, Maryland. RESULTS: Four themes emerged from thematic content analysis: 1) current health and perceptions of dialysis, 2) support while undergoing dialysis, 3) interactions with medical professionals, and 4) concerns about KT. Females and older males tended to be more positive about dialysis experiences. Younger males expressed a lack of support from friends and family. All participants shared feelings of being treated poorly by medical professionals and lacking information about renal disease and treatment options. Common concerns about pursuing KT were increased medication burden, fear of surgery, fear of organ rejection, and older age (among older participants). CONCLUSIONS: These perceptions may contribute to disparities in access to KT, motivating granular studies based on the themes identified

    Spatially distributed dendritic resonance selectively filters synaptic input

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    © 2014 Laudanski et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.An important task performed by a neuron is the selection of relevant inputs from among thousands of synapses impinging on the dendritic tree. Synaptic plasticity enables this by strenghtening a subset of synapses that are, presumably, functionally relevant to the neuron. A different selection mechanism exploits the resonance of the dendritic membranes to preferentially filter synaptic inputs based on their temporal rates. A widely held view is that a neuron has one resonant frequency and thus can pass through one rate. Here we demonstrate through mathematical analyses and numerical simulations that dendritic resonance is inevitably a spatially distributed property; and therefore the resonance frequency varies along the dendrites, and thus endows neurons with a powerful spatiotemporal selection mechanism that is sensitive both to the dendritic location and the temporal structure of the incoming synaptic inputs.Peer reviewe

    Budd-Chiari Syndrome: Long term success via hepatic decompression using transjugular intrahepatic porto-systemic shunt

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    <p>Abstract</p> <p>Background</p> <p>Budd-Chiari syndrome (BCS) generally implies thrombosis of the hepatic veins and/or the intrahepatic or suprahepatic inferior vena cava. Treatment depends on the underlying cause, the anatomic location, the extent of the thrombotic process and the functional capacity of the liver. It can be divided into medical treatment including anticoagulation and thrombolysis, radiological procedures such as angioplasty and transjugular intrahepatic porto-systemic shunt (TIPS) and surgical interventions including orthotopic liver transplantation (OLT). Controlled trials or reports on larger cohorts are limited due to rare disease frequency. The aim of this study was to report our single centre long term results of patients with BCS receiving one of three treatment options i.e. medication only, TIPS or OLT on an individually based decision of our local expert group.</p> <p>Methods</p> <p>20 patients with acute, subacute or chronic BCS were treated between 1988 and 2008. Clinical records were analysed with respect to underlying disease, therapeutic interventions, complications and overall outcome.</p> <p>Results</p> <p>16 women and 4 men with a mean age of 34 ± 12 years (range: 14-60 years) at time of diagnosis were included. Myeloproliferative disorders or a plasmatic coagulopathy were identified as underlying disease in 13 patients, in the other patients the cause of BCS remained unclear. 12 patients presented with an acute BCS, 8 with a subacute or chronic disease. 13 patients underwent TIPS, 4 patients OLT as initial therapy, 2 patients required only symptomatic therapy, and one patient died from liver failure before any specific treatment could be initiated. Eleven of 13 TIPS patients required 2.5 ± 2.4 revisions (range: 0-8). One patient died from his underlying hematologic disease. The residual 12 patients still have stable liver function not requiring OLT. All 4 patients who underwent OLT as initial treatment, required re-OLT due to thrombembolic complications of the graft. Survival in the TIPS group was 92.3% and in the OLT group 75% during a median follow-up of 4 and 11.5 years, respectively.</p> <p>Conclusion</p> <p>Our results confirm the role of TIPS in the management of patients with acute, subacute and chronic BCS. The limited number of patients with OLT does not allow to draw a meaningful conclusion. However, the underlying disease may generate major complications, a reason why OLT should be limited to patients who cannot be managed by TIPS.</p

    Sparsity-based single-shot sub-wavelength coherent diffractive imaging

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    We present the experimental reconstruction of sub-wavelength features from the far-field intensity of sparse optical objects: sparsity-based sub-wavelength imaging combined with phase-retrieval. As examples, we demonstrate the recovery of random and ordered arrangements of 100 nm features with the resolution of 30 nm, with an illuminating wavelength of 532 nm. Our algorithmic technique relies on minimizing the number of degrees of freedom; it works in real-time, requires no scanning, and can be implemented in all existing microscopes - optical and non-optical
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