University of Rochester

About: University of Rochester is a education organization based out in Rochester, New York, United States. It is known for research contribution in the topics: Population & Laser. The organization has 63915 authors who have published 112762 publications receiving 5484122 citations. The organization is also known as: Rochester University.

The population genetics of adaptation : the distribution of factors fixed during adaptive evolution

Abstract: We know very little about the genetic basis of adaptation. Indeed, we can make no theoretical predictions, however heuristic, about the distribution of phenotypic effects among factors fixed during adaptation nor about the expected "size" of the largest factor fixed. Study of this problem requires taking into account that populations gradually approach a phenotypic optimum during adaptation via the stepwise substitution of favorable mutations. Using Fisher's geometric model of adaptation, I analyze this approach to the optimum, and derive an approximate solution to the size distribution of factors fixed during adaptation. I further generalize these results to allow the input of any distribution of mutational effects. The distribution of factors fixed during adaptation assumes a pleasingly simple, exponential form. This result is remarkably insensitive to changes in the fitness function and in the distribution of mutational effects. An exponential trend among factors fixed appears to be a general property of adaptation toward a fixed optimum.

Practical assessment and management of vulnerabilities in older patients receiving chemotherapy: Asco guideline for geriatric oncology

Abstract: Purpose To provide guidance regarding the practical assessment and management of vulnerabilities in older patients undergoing chemotherapy. Methods An Expert Panel was convened to develop clinical practice guideline recommendations based on a systematic review of the medical literature. Results A total of 68 studies met eligibility criteria and form the evidentiary basis for the recommendations. Recommendations In patients ≥ 65 years receiving chemotherapy, geriatric assessment (GA) should be used to identify vulnerabilities that are not routinely captured in oncology assessments. Evidence supports, at a minimum, assessment of function, comorbidity, falls, depression, cognition, and nutrition. The Panel recommends instrumental activities of daily living to assess for function, a thorough history or validated tool to assess comorbidity, a single question for falls, the Geriatric Depression Scale to screen for depression, the Mini-Cog or the Blessed Orientation-Memory-Concentration test to screen for cognitive impairment, and an assessment of unintentional weight loss to evaluate nutrition. Either the CARG (Cancer and Aging Research Group) or CRASH (Chemotherapy Risk Assessment Scale for High-Age Patients) tools are recommended to obtain estimates of chemotherapy toxicity risk; the Geriatric-8 or Vulnerable Elders Survey-13 can help to predict mortality. Clinicians should use a validated tool listed at ePrognosis to estimate noncancer-based life expectancy ≥ 4 years. GA results should be applied to develop an integrated and individualized plan that informs cancer management and to identify nononcologic problems amenable to intervention. Collaborating with caregivers is essential to implementing GA-guided interventions. The Panel suggests that clinicians take into account GA results when recommending chemotherapy and that the information be provided to patients and caregivers to guide treatment decision making. Clinicians should implement targeted, GA-guided interventions to manage nononcologic problems. Additional information is available at www.asco.org/supportive-care-guidelines .

Molecular diagnosis of Burkitt's lymphoma.

Abstract: Background The distinction between Burkitt’s lymphoma and diffuse large-B-cell lymphoma is crucial because these two types of lymphoma require different treatments. We examined whether gene-expression profiling could reliably distinguish Burkitt’s lymphoma from diffuse large-B-cell lymphoma. Methods Tumor-biopsy specimens from 303 patients with aggressive lymphomas were profiled for gene expression and were also classified according to morphology, immunohistochemistry, and detection of the t(8;14) c-myc translocation. Results A classifier based on gene expression correctly identified all 25 pathologically verified cases of classic Burkitt’s lymphoma. Burkitt’s lymphoma was readily distinguished from diffuse large-B-cell lymphoma by the high level of expression of c-myc target genes, the expression of a subgroup of germinal-center B-cell genes, and the low level of expression of major-histocompatibility-complex class I genes and nuclear factor-κB target genes. Eight specimens with a pathological diagnosis of diffuse large-B-cell lymphoma had the typical gene-expression profile of Burkitt’s lymphoma, suggesting they represent cases of Burkitt’s lymphoma that are difficult to diagnose by current methods. Among 28 of the patients with a molecular diagnosis of Burkitt’s lymphoma, the overall survival was superior among those who had received intensive chemotherapy regimens instead of lower-dose regimens. Conclusions Gene-expression profiling is an accurate, quantitative method for distinguishing Burkitt’s lymphoma from diffuse large-B-cell lymphoma.

Effect of Laparoscopic-Assisted Resection vs Open Resection of Stage II or III Rectal Cancer on Pathologic Outcomes: The ACOSOG Z6051 Randomized Clinical Trial

Abstract: Importance Evidence about the efficacy of laparoscopic resection of rectal cancer is incomplete, particularly for patients with more advanced-stage disease. Objective To determine whether laparoscopic resection is noninferior to open resection, as determined by gross pathologic and histologic evaluation of the resected proctectomy specimen. Design, setting, and participants A multicenter, balanced, noninferiority, randomized trial enrolled patients between October 2008 and September 2013. The trial was conducted by credentialed surgeons from 35 institutions in the United States and Canada. A total of 486 patients with clinical stage II or III rectal cancer within 12 cm of the anal verge were randomized after completion of neoadjuvant therapy to laparoscopic or open resection. Interventions Standard laparoscopic and open approaches were performed by the credentialed surgeons. Main outcomes and measures The primary outcome assessing efficacy was a composite of circumferential radial margin greater than 1 mm, distal margin without tumor, and completeness of total mesorectal excision. A 6% noninferiority margin was chosen according to clinical relevance estimation. Results Two hundred forty patients with laparoscopic resection and 222 with open resection were evaluable for analysis of the 486 enrolled. Successful resection occurred in 81.7% of laparoscopic resection cases (95% CI, 76.8%-86.6%) and 86.9% of open resection cases (95% CI, 82.5%-91.4%) and did not support noninferiority (difference, -5.3%; 1-sided 95% CI, -10.8% to ∞; P for noninferiority = .41). Patients underwent low anterior resection (76.7%) or abdominoperineal resection (23.3%). Conversion to open resection occurred in 11.3% of patients. Operative time was significantly longer for laparoscopic resection (mean, 266.2 vs 220.6 minutes; mean difference, 45.5 minutes; 95% CI, 27.7-63.4; P Conclusions and relevance Among patients with stage II or III rectal cancer, the use of laparoscopic resection compared with open resection failed to meet the criterion for noninferiority for pathologic outcomes. Pending clinical oncologic outcomes, the findings do not support the use of laparoscopic resection in these patients. Trial registration clinicaltrials.gov Identifier: NCT00726622.

Stability of Intelligence from Preschool to Adolescence: The Influence of Social and Family Risk Factors

Abstract: Intelligence scores of children in a longitudinal study were assessed at 4 and 13 years and related to social and family risk factors. A multiple environmental risk score was calculated for each child by counting the number of high-risk conditions from 10 risk factors: mother's behavior, mother's developmental beliefs, mother's anxiety, mother's mental health, mother's educational attainment, family social support, family size, major stressful life events, occupation of head of household, and disadvantaged minority status. Multiple risk scores explained one-third to one-half of IQ variance at 4 and 13 years. The stability between 4- and 13-year environmental risk scores (r = .77) was not less than the stability between between 4- and 13-year IQ scores (r = .72). Effects remained after SES and race, or maternal IQ, were partialled; multiple risk was important in longitudinal prediction, even after prior measurement of child IQ was accounted for; the pattern of risk was less important than the total amount of risk present in the child's context.