332 research outputs found
The Impact of Histological Subtype on the Incidence, Timing, and Patterns of Recurrence in Patients with Renal Cell Carcinoma After Surgery-Results from RECUR Consortium
Background: Current follow-up strategies for patients with renal cell carcinoma (RCC) after curative surgery rely mainly on risk models and the treatment delivered, regardless of the histological subtype. Objective: To determine the impact of RCC histological subtype on recurrence and to examine the incidence, pattern, and timing of recurrences to improve follow-up recommendations. Design, setting, and participants: This study included consecutive patients treated surgically with curative intention (ie, radical and partial nephrectomy) for non-metastatic RCC (cT1-4, M0) between January 2006 and December 2011 across 15 centres from 10 countries, as part of the euRopEan association of urology renal cell carcinoma guidelines panel Collaborative multicenter consortium for the studies of follow-Up and recurrence patterns in Radically treated renal cell carcinoma patients (RECUR) database project. Outcome measurements and statistical analysis: The impact of histological subtype (ie, clear cell RCC [ccRCC], papillary RCC [pRCC], and chromophobe RCC [chRCC]) on recurrence-free survival (RFS) was assessed via univariate and multivariate analyses, adjusting for potential interactions with important variables (stage, grade, risk score, etc.) Patterns of recurrence for all histological subtypes were compared according to recurrence site and risk criteria. Results and limitations: Of the 3331 patients, 62.2% underwent radical nephrectomy and 37.8% partial nephrectomy. A total of 2565 patients (77.0%) had ccRCC, 535 (16.1%) had pRCC, and 231 (6.9%) had chRCC. The median postoperative follow-up period was 61.7 (interquartile range: 47-83) mo. Patients with ccRCC had significantly poorer 5-yr RFS than patients with pRCC and chRCC (78% vs 86% vs 91%, p = 0.001). The most common sites of recurrence for ccRCC were the lung and bone. Intermediate-/high-risk pRCC patients had an increased rate of lymphatic recurrence, both mediastinal and retroperitoneal, while recurrence in chRCC was rare (8.2%), associated with higher stage and positive margins, and predominantly in the liver and bone. Limitations include the retrospective nature of the study. Conclusions: The main histological subtypes of RCC exhibit a distinct pattern and dynamics of recurrence. Results suggest that intermediate- to high-risk pRCC may benefit from cross-sectional abdominal imaging every 6 mo until 2 yr after surgery, while routine imaging might be abandoned for chRCC except for abdominal computed tomography in patients with advanced tumour stage or positive margins. Patient summary: In this analysis of a large database from 15 countries around Europe, we found that the main histological subtypes of renal cell carcinoma have a distinct pattern and dynamics of recurrence. Patients should be followed differently according to subtype and risk score. (C) 2020 Published by Elsevier B.V. on behalf of European Association of Urology.Peer reviewe
Island extinctions: processes, patterns, and potential for ecosystem restoration
Extinctions have altered island ecosystems throughout the late Quaternary. Here, we review the main historic drivers of extinctions on islands, patterns in extinction chronologies between islands, and the potential for restoring ecosystems through reintroducing extirpated species. While some extinctions have been caused by climatic and environmental change, most have been caused by anthropogenic impacts. We propose a general model to describe patterns in these anthropogenic island extinctions. Hunting, habitat loss and the introduction of invasive predators accompanied prehistoric settlement and caused declines of endemic island species. Later settlement by European colonists brought further land development, a different suite of predators and new drivers, leading to more extinctions. Extinctions alter ecological networks, causing ripple effects for islands through the loss of ecosystem processes, functions and interactions between species. Reintroduction of extirpated species can help restore ecosystem function and processes, and can be guided by palaeoecology. However, reintroduction projects must also consider the cultural, social and economic needs of humans now inhabiting the islands and ensure resilience against future environmental and climate change
A spindle cell carcinoma presenting with osseous metaplasia in the gingiva: a case report with immunohistochemical analysis
<p>Abstract</p> <p>Background</p> <p>Spindle cell carcinoma (SpCC) is a rare, high malignant variant of squamous cell carcinoma (SCC), which shows biphasic proliferation of conventional SCC component and malignant spindle shape cells with sarcomatous appearance.</p> <p>Methods</p> <p>A case of Spindle cell carcinoma with bone-like calcified materials, occurring at the mandibular molar region of 71-years-old Japanese male patient was presented with gross finding, histological findings and MRI image. To identify the characteristics of the bone-like materials, immunohistochemistry were performed.</p> <p>Results</p> <p>Histologically, the cancer cells were composed of spindle cells and epithelial cells which form nests with prominent keratinization. Histological findings showed typical histology of the SpCC, however, as an uncommon finding, spatters of calcified, bone-like materials were observed in between the cancer cells. Immunohistochemistry revealed that cancer cells were positive for cytokeratins and vimentin to a varying degree and negative for Desmin, S-100, Osteopontin, BMP-2 or BMP-4. These findings implied that the calcified materials were formed by metaplasia of the stromal cells.</p> <p>Discussion</p> <p>Bone-like materials formation by osseous and/or cartilaginous metaplasia of the stroma in the carcinoma has been reported. However, the detailed mechanism of these metaplasia and affection on the clinical feature, prognosis and therapies are not well established. In summary, we presented an unique case of SpCC, which has not been described in the literature.</p
Tunable Frohlich Polarons in Organic Single-Crystal Transistors
In organic field effect transistors (FETs), charges move near the surface of
an organic semiconductor, at the interface with a dielectric. In the past, the
nature of the microscopic motion of charge carriers -that determines the device
performance- has been related to the quality of the organic semiconductor.
Recently, it has been appreciated that also the nearby dielectric has an
unexpectedly strong influence. The mechanisms responsible for this influence
are not understood. To investigate these mechanisms we have studied transport
through organic single crystal FETs with different gate insulators. We find
that the temperature dependence of the mobility evolves from metallic-like to
insulating-like with increasing the dielectric constant of the insulator. The
phenomenon is accounted for by a two-dimensional Frohlich polaron model that
quantitatively describes our observations and shows that increasing the
dielectric polarizability results in a crossover from the weak to the strong
polaronic coupling regime
Estimates of adherence and error analysis of physical activity data collected via accelerometry in a large study of free-living adults
<p>Abstract</p> <p>Background</p> <p>Activity monitors (AM) are small, electronic devices used to quantify the amount and intensity of physical activity (PA). Unfortunately, it has been demonstrated that data loss that occurs when AMs are not worn by subjects (removals during sleeping and waking hours) tend to result in biased estimates of PA and total energy expenditure (TEE). No study has reported the degree of data loss in a large study of adults, and/or the degree to which the estimates of PA and TEE are affected. Also, no study in adults has proposed a methodology to minimize the effects of AM removals.</p> <p>Methods</p> <p>Adherence estimates were generated from a pool of 524 women and men that wore AMs for 13 – 15 consecutive days. To simulate the effect of data loss due to AM removal, a reference dataset was first compiled from a subset consisting of 35 highly adherent subjects (24 HR; minimum of 20 hrs/day for seven consecutive days). AM removals were then simulated during sleep and between one and ten waking hours using this 24 HR dataset. Differences in the mean values for PA and TEE between the 24 HR reference dataset and the different simulations were compared using paired <it>t</it>-tests and/or coefficients of variation.</p> <p>Results</p> <p>The estimated average adherence of the pool of 524 subjects was 15.8 ± 3.4 hrs/day for approximately 11.7 ± 2.0 days. Simulated data loss due to AM removals during sleeping hours in the 24 HR database (n = 35), resulted in biased estimates of PA (p < 0.05), but not TEE. Losing as little as one hour of data from the 24 HR dataset during waking hours results in significant biases (p < 0.0001) and variability (coefficients of variation between 7 and 21%) in the estimates of PA. Inserting a constant value for sleep and imputing estimates for missing data during waking hours significantly improved the estimates of PA.</p> <p>Conclusion</p> <p>Although estimated adherence was good, measurements of PA can be improved by relatively simple imputation of missing AM data.</p
Investigation of the Mechanism of Clearance of AMG 386, a Selective Angiopoietin-1/2 Neutralizing Peptibody, in Splenectomized, Nephrectomized, and FcRn Knockout Rodent Models
Clinical practice. Diagnosis and treatment of cow’s milk allergy
Introduction Cow's milk allergy (CMA) is thought to affect 2-3% of infants. The signs and symptoms are nonspecific and may be difficult to objectify, and as the diagnosis requires cow's milk elimination followed by challenge, often, children are considered cow's milk allergic without proven diagnosis. Diagnosis Because of the consequences, a correct diagnosis of CMA is pivotal. Open challenges tend to overestimate the number of children with CMA. The only reliable way to diagnose CMA is by double-blind, placebo-controlled challenge (DBPCFC). Therapy At present, the only proven treatment consists of elimination of cow's milk protein from the child's diet and the introduction of formulas based on extensively hydrolysed whey protein or casein; amino acid-based formula is rarely indicated. The majority of children will regain tolerance to cow's milk within the first 5 years of life. Conclusions Open challenges can be used to reject CMA, but for adequate diagnosis, DBPCFC is mandatory. In most children, CMA can be adequately treated with extensively hydrolysed whey protein or casein formulas
Identification of uPAR-positive Chemoresistant Cells in Small Cell Lung Cancer
BACKGROUND: The urokinase plasminogen activator (uPA) and its receptor (uPAR/CD87) are major regulators of extracellular matrix degradation and are involved in cell migration and invasion under physiological and pathological conditions. The uPA/uPAR system has been of great interest in cancer research because it is involved in the development of most invasive cancer phenotypes and is a strong predictor of poor patient survival. However, little is known about the role of uPA/uPAR in small cell lung cancer (SCLC), the most aggressive type of lung cancer. We therefore determined whether uPA and uPAR are involved in generation of drug resistant SCLC cell phenotype. METHODS AND FINDINGS: We screened six human SCLC cell lines for surface markers for putative stem and cancer cells. We used fluorescence-activated cell sorting (FACS), fluorescence microscopy and clonogenic assays to demonstrate uPAR expression in a subpopulation of cells derived from primary and metastatic SCLC cell lines. Cytotoxic assays were used to determine the sensitivity of uPAR-positive and uPAR-negative cells to chemotherapeutic agents. The uPAR-positive cells in all SCLC lines demonstrated multi-drug resistance, high clonogenic activity and co-expression of CD44 and MDR1, putative cancer stem cell markers. CONCLUSIONS: These data suggest that uPAR-positive cells may define a functionally important population of cancer cells in SCLC, which are resistant to traditional chemotherapies, and could serve as critical targets for more effective therapeutic interventions in SCLC
Expression of the Axonal Membrane Glycoprotein M6a Is Regulated by Chronic Stress
It has been repeatedly shown that chronic stress changes dendrites, spines and modulates expression of synaptic molecules. These effects all may impair information transfer between neurons. The present study shows that chronic stress also regulates expression of M6a, a glycoprotein which is localised in axonal membranes. We have previously demonstrated that M6a is a component of glutamatergic axons. The present data reveal that it is the splice variant M6a-Ib, not M6a-Ia, which is strongly expressed in the brain. Chronic stress in male rats (3 weeks daily restraint) has regional effects: quantitative in situ hybridization demonstrated that M6a-Ib mRNA in dentate gyrus granule neurons and in CA3 pyramidal neurons is downregulated, whereas M6a-Ib mRNA in the medial prefrontal cortex is upregulated by chronic stress. This is the first study showing that expression of an axonal membrane molecule is differentially affected by stress in a region-dependent manner. Therefore, one may speculate that diminished expression of the glycoprotein in the hippocampus leads to altered output in the corresponding cortical projection areas. Enhanced M6a-Ib expression in the medial prefrontal cortex (in areas prelimbic and infralimbic cortex) might be interpreted as a compensatory mechanism in response to changes in axonal projections from the hippocampus. Our findings provide evidence that in addition to alterations in dendrites and spines chronic stress also changes the integrity of axons and may thus impair information transfer even between distant brain regions
Anatomical Versus Nonanatomical Resection of Colorectal Liver Metastases: Is There a Difference in Surgical and Oncological Outcome?
Background: The increased use of neoadjuvant chemotherapy and minimally invasive therapies for recurrence in patients with colorectal liver metastases (CLM) makes a surgical strategy
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