532 research outputs found
Mutational status of nevus-associated melanomas.
Introduction Melanoma origin has always been a debated subject, as well as the role of adjacent melanocytic nevi. Epidemiological and histopathological studies point to melanomas arising either de novo or from a nevus. Methods Sixty-one melanomas found in association with a preexisting nevus were microdissected, after careful selection of cell subpopulations and submitted to Sanger sequencing of the BRAF, NRAS, C-KIT, PPP6C, STK19 and RAC1 genes. Each gene was evaluated twice in all samples by sequencing or by sequencing and another confirmation method, allele-specific fluorescent polymerase chain reaction (PCR) and capillary electrophoresis detection, or by SNaPshot Analysis. Only mutations confirmed via two different molecular methods or twice by sequencing were considered positive. Results The majority of cases presented concordance of mutational status between melanoma and the associated nevus for all 6 genes (40/60; 66.7%). Nine cases presented concomitant BRAF and NRAS mutations, including one case, in which both the melanoma and the adjacent nevus harbored V600E and Q61K double mutations. In two cases, both melanoma and associated nevus, located on acral sites were BRAF mutated, including an acral lentiginous melanoma. Conclusions This is the largest nevus-associated melanoma series molecularly evaluated to our knowledge. The majority of melanomas and adjacent nevi in our sample share the same mutational profile, corroborating the theory that the adjacent nevus and melanoma are clonally related and that melanoma originated within a nevus
Association of MC1R Variants and host phenotypes with melanoma risk in CDKN2A mutation carriers: a GenoMEL study
<p><b>Background</b> Carrying the cyclin-dependent kinase inhibitor 2A (CDKN2A) germline mutations is associated with a high risk for melanoma. Penetrance of CDKN2A mutations is modified by pigmentation characteristics, nevus phenotypes, and some variants of the melanocortin-1 receptor gene (MC1R), which is known to have a role in the pigmentation process. However, investigation of the associations of both MC1R variants and host phenotypes with melanoma risk has been limited.</p>
<p><b>Methods</b> We included 815 CDKN2A mutation carriers (473 affected, and 342 unaffected, with melanoma) from 186 families from 15 centers in Europe, North America, and Australia who participated in the Melanoma Genetics Consortium. In this family-based study, we assessed the associations of the four most frequent MC1R variants (V60L, V92M, R151C, and R160W) and the number of variants (1, ≥2 variants), alone or jointly with the host phenotypes (hair color, propensity to sunburn, and number of nevi), with melanoma risk in CDKN2A mutation carriers. These associations were estimated and tested using generalized estimating equations. All statistical tests were two-sided.</p>
<p><b>Results</b> Carrying any one of the four most frequent MC1R variants (V60L, V92M, R151C, R160W) in CDKN2A mutation carriers was associated with a statistically significantly increased risk for melanoma across all continents (1.24 Ă 10â6 ≤ P ≤ .0007). A consistent pattern of increase in melanoma risk was also associated with increase in number of MC1R variants. The risk of melanoma associated with at least two MC1R variants was 2.6-fold higher than the risk associated with only one variant (odds ratio = 5.83 [95% confidence interval = 3.60 to 9.46] vs 2.25 [95% confidence interval = 1.44 to 3.52]; Ptrend = 1.86 Ă 10â8). The joint analysis of MC1R variants and host phenotypes showed statistically significant associations of melanoma risk, together with MC1R variants (.0001 ≤ P ≤ .04), hair color (.006 ≤ P ≤ .06), and number of nevi (6.9 Ă 10â6 ≤ P ≤ .02).</p>
<p><b>Conclusion</b> Results show that MC1R variants, hair color, and number of nevi were jointly associated with melanoma risk in CDKN2A mutation carriers. This joint association may have important consequences for risk assessments in familial settings.</p>
Uncoupling protein-1 (UCP1) contributes to the basal proton conductance of brown adipose tissue mitochondria
Proton leak pathways uncouple substrate oxidation from ATP synthesis in mitochondria. These pathways are classified as basal (not regulated) or inducible (activated and inhibited). Previously it was found that over half of the basal proton conductance of muscle mitochondria was catalyzed by the adenine nucleotide translocase (ANT), an abundant mitochondrial anion carrier protein. To determine whether ANT is the unique protein catalyst, or one of many proteins that catalyze basal proton conductance, we measured proton leak kinetics in mitochondria isolated from brown adipose tissue (BAT). BAT can express another mitochondrial anion carrier, UCP1, at concentrations similar to ANT. Basal proton conductance was measured under conditions where UCP1 and ANT were catalytically inactive and was found to be lower in mitochondria from UCP1 knockout mice compared to wild-type. Ablation of another abundant inner membrane protein, nicotinamide nucleotide transhydrogenase, had no effect on proton leak kinetics in mitochondria from liver, kidney or muscle, showing that basal proton conductance is not catalyzed by all membrane proteins. We identify UCP1 as a second protein propagating basal proton leak, lending support to the hypothesis that basal leak pathways are perpetrated by members of the mitochondrial anion carrier family but not by other mitochondrial inner membrane proteins
Income in Adult Survivors of Childhood Cancer.
INTRODUCTION: Little is known about the impact of childhood cancer on the personal income of survivors. We compared income between survivors and siblings, and determined factors associated with income. METHODS: As part of the Swiss Childhood Cancer Survivor Study (SCCSS), a questionnaire was sent to survivors, aged â„18 years, registered in the Swiss Childhood Cancer Registry (SCCR), diagnosed at age 4'500 CHF), even after we adjusted for socio-demographic and educational factors (OR = 0.46, p<0.001). Older age, male sex, personal and parental education, and number of working hours were associated with high income. Survivors of leukemia (OR = 0.40, p<0.001), lymphoma (OR = 0.63, p = 0.040), CNS tumors (OR = 0.22, p<0.001), bone tumors (OR = 0.24, p = 0.003) had a lower income than siblings. Survivors who had cranial irradiation, had a lower income than survivors who had no cranial irradiation (OR = 0.48, p = 0.006). DISCUSSION: Even after adjusting for socio-demographic characteristics, education and working hours, survivors of various diagnostic groups have lower incomes than siblings. Further research needs to identify the underlying causes
Rectal cancer treatment and outcome in the elderly: an audit based on the Swedish rectal cancer registry 1995â2004
<p>Abstract</p> <p>Background</p> <p>Limited information is available regarding the effect of age on choice of surgical and oncological treatment for rectal cancer. The objective of this study was to assess the influence of age on treatment and outcome of rectal cancer.</p> <p>Methods</p> <p>We utilized data in the Swedish Rectal Cancer Registry (SRCR) from patients treated for rectal cancer in Sweden in 1995â2004.</p> <p>Results</p> <p>A total of 15,104 patients with rectal cancer were identified, 42.4% of whom were 75 years or older. Patients â„75 years were less likely to have distant metastases than younger patients (14.8% vs. 17.8%, <it>P </it>< 0.001), and underwent abdominal tumor resection less frequently (68.5% vs. 84.4%, <it>P </it>< 0.001). Of 11,725 patients with abdominal tumor resection (anterior resection [AR], abdominoperineal excision [APE], and Hartmann's procedure [HA]), 37.4% were â„75 years. Curative surgery was registered for 85.0% of patients â„ 75 years and for 83.9% of patients < 75 years, <it>P </it>= 0.11. Choice of abdominal operation differed significantly between the two age groups for both curative and non-curative surgery, The frequency of APE was similar in both age groups (29.5% vs. 28.6%), but patients â„75 years were more likely to have HA (16.9% vs. 4.9%) and less likely to have preoperative radiotherapy (34.3vs. 67.2%, <it>P </it>< 0.001). The relative survival rate at five years for all patients treated with curative intent was 73% (70â75%) for patients â„75 years and 78% (77â79%) for patients < 75 years of age. Local recurrence rate was 9% (8â11%) for older and 8% (7â9%) for younger patients.</p> <p>Conclusion</p> <p>Treatment of rectal cancer is influenced by patient's age. Future studies should include younger and older patients alike to reveal whether or not age-related differences are purposive. Local recurrence following surgery for low tumors and quality of life aspects deserve particular attention.</p
Hippocampal Deletion of BDNF Gene Attenuates Gamma Oscillations in Area CA1 by Up-Regulating 5-HT3 Receptor
Background: Pyramidal neurons in the hippocampal area CA3 express high levels of BDNF, but how this BDNF contributes to oscillatory properties of hippocampus is unknown. Methodology/Principal Findings: Here we examined carbachol-induced gamma oscillations in hippocampal slices lacking BDNF gene in the area CA3. The power of oscillations was reduced in the hippocampal area CA1, which coincided with increases in the expression and activity of 5-HT3 receptor. Pharmacological block of this receptor partially restored power of gamma oscillations in slices from KO mice, but had no effect in slices from WT mice. Conclusion/Significance: These data suggest that BDNF facilitates gamma oscillations in the hippocampus by attenuating signaling through 5-HT3 receptor. Thus, BDNF modulates hippocampal oscillations through serotonergic system
Hepatitis C virus quasispecies in chronically infected children subjected to interferonâribavirin therapy
Accumulating evidence suggests that certain features of hepatitis C virus (HCV), especially its high genetic variability, might be responsible for the low efficiency of anti-HCV treatment. Here, we present a bioinformatic analysis of HCV-1a populations isolated from 23 children with chronic hepatitis C (CHC) subjected to interferonâribavirin therapy. The structures of the viral quasispecies were established based on a 132-amino-acid sequence derived from E1/E2 protein, including hypervariable region 1 (HVR1). Two types of HCV populations were identified. The first type, found in non-responders, contained a small number of closely related variants. The second type, characteristic for sustained responders, was composed of a large number of distantly associated equal-rank variants. Comparison of 445 HVR1 sequences showed that a significant number of variants present in non-responding patients are closely related, suggesting that certain, still unidentified properties of the pathogen may be key factors determining the result of CHC treatment
Reliability and validity of PedsQL for Portuguese children aged 5â7 and 8â12 years
BACKGROUND: Pediatric Quality of Life Inventory (PedsQL) is a measure to assess health-related quality of life (HRQoL) in children and adolescents. It is formed by 23 items adapted to children age and includes a parent proxy report version. With four multidimensional subscales and three summary scores, it measures health as defined by WHO. The concepts measured by this instrument are âphysical functioningâ (8 items), âemotional functioningâ (5 items), âsocial functioningâ (5 items) and âschool functioningâ (5 items). It also measures a âtotal scale scoreâ (23 items), a âphysical health summary scoreâ (8 items) and a âpsychosocial health summary scoreâ (15 items). The aim of this paper is to present the main results of the cultural adaptation and validation of the PedsQL into European Portuguese. METHODS: The Portuguese version was the result of a forward-backward translation process, with a cognitive debriefing analysis, guaranteeing face validity and semantic equivalence. Children aged 5â7 and 8â12 were randomly selected and were asked to fill a socio-demographic data survey and the Portuguese versions of PedsQL and KINDL, another HRQoL measure for children and adolescents. They were divided into three groups, healthy children, children with type I diabetes and children with spina bifida. The reliability was tested for reproducibility (ICC) and internal consistency (Cronbachâs alpha). The construct validity (known-groups discriminant validity) was supported by differences between self-reports from healthy children and children with chronic conditions, and from children with chronic diseases and their parents. The criterion validity was tested after the correlations of the scores obtained by both children and adolescents HRQoL assessment instruments. RESULTS: A total of 179 children and 97 parents were recruited. PedsQL demonstrated good levels of reproducibility (r > 0.95 in all versions) and acceptable levels of internal consistency with Cronbachâs alpha at 0.70 on most scales. Concordance values between childrenâs and parentsâ perceptions ranged between 0.36 and 0.78 and the correlations with KINDL questionnaire were excellent, supporting concurrent validity. CONCLUSIONS: The Portuguese version of the PedsQL demonstrated acceptable psychometric properties for future research and clinical practice for children aged 5â12
Search for CP violation in D+âÏÏ+ and D+sâK0SÏ+ decays
A search for CP violation in D + â ÏÏ + decays is performed using data collected in 2011 by the LHCb experiment corresponding to an integrated luminosity of 1.0 fbâ1 at a centre of mass energy of 7 TeV. The CP -violating asymmetry is measured to be (â0.04 ± 0.14 ± 0.14)% for candidates with K â K + mass within 20 MeV/c 2 of the Ï meson mass. A search for a CP -violating asymmetry that varies across the Ï mass region of the D + â K â K + Ï + Dalitz plot is also performed, and no evidence for CP violation is found. In addition, the CP asymmetry in the D+sâK0SÏ+ decay is measured to be (0.61 ± 0.83 ± 0.14)%
Utilisation of an operative difficulty grading scale for laparoscopic cholecystectomy
Background
A reliable system for grading operative difficulty of laparoscopic cholecystectomy would standardise description of findings and reporting of outcomes. The aim of this study was to validate a difficulty grading system (Nassar scale), testing its applicability and consistency in two large prospective datasets.
Methods
Patient and disease-related variables and 30-day outcomes were identified in two prospective cholecystectomy databases: the multi-centre prospective cohort of 8820 patients from the recent CholeS Study and the single-surgeon series containing 4089 patients. Operative data and patient outcomes were correlated with Nassar operative difficultly scale, using Kendallâs tau for dichotomous variables, or JonckheereâTerpstra tests for continuous variables. A ROC curve analysis was performed, to quantify the predictive accuracy of the scale for each outcome, with continuous outcomes dichotomised, prior to analysis.
Results
A higher operative difficulty grade was consistently associated with worse outcomes for the patients in both the reference and CholeS cohorts. The median length of stay increased from 0 to 4 days, and the 30-day complication rate from 7.6 to 24.4% as the difficulty grade increased from 1 to 4/5 (both pâ<â0.001). In the CholeS cohort, a higher difficulty grade was found to be most strongly associated with conversion to open and 30-day mortality (AUROCâ=â0.903, 0.822, respectively). On multivariable analysis, the Nassar operative difficultly scale was found to be a significant independent predictor of operative duration, conversion to open surgery, 30-day complications and 30-day reintervention (all pâ<â0.001).
Conclusion
We have shown that an operative difficulty scale can standardise the description of operative findings by multiple grades of surgeons to facilitate audit, training assessment and research. It provides a tool for reporting operative findings, disease severity and technical difficulty and can be utilised in future research to reliably compare outcomes according to case mix and intra-operative difficulty
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