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.

A Golgi study of cell types in the hilar region of the hippocampus in the rat.

Abstract: The morphology of neurons in the "hilar region" of the hippocampus (fields CA3c and CA4 of Lorente de No, '34) was analyzed with several variants of the Golgi technique. Hippocampi were dissected from the brains of 28-day-old rats, fixed and impregnated by immersion, and sectioned perpendicular to the long axis. Based on the resident cell types, aspects of the neuropil, and published data related to afferent termination, the area under study was divided into four zones. At least 21 cell types were observed throughout these zones, several of which had not previously been described. Many cells in this area exhibited an impressive number and variety of dendritic and axonal appendages, including spines on the proximal portion of some axons. The close apposition of fibers to these axonal spines suggested the possibility of axo-axonal interactions. The influence of dentate granule cells, through their mossy fibers, on the synaptic economy of the "hilar region" was found to be more extensive than previously reported. Mossy fibers appeared to terminate on the dendrites of several types of non-pyramidal cells, which bear no thorny excrescences, by means of thin filiform extensions which emanate from the mossy fiber expansions and by means of thin mossy fiber collaterals which are devoid of typical expansions. Consideration is given to a long-standing debate as to whether the deep "hilar region" (CA4 of Lorente de No, '34, hilus of the fascia dentata of Blackstad, '56) is related more to the hippocampus or to the fascia dentata and it is concluded that the deep hilar region is an area of mergence of the polymorphic zones of these two cortical structures. The results of the present study do not support the proposition that the deep hilar region is an extension of the pyramidal layer of the hippocampus as suggested by Lorente de No ('34), and thus CA4 is a misnomer. Rather, the cells in this area are most closely related to the fascia dentata and should thus be considered to lie in the polymorphic zone of "area dentata" as proposed initially by Blackstad ('56).

Origins and pawns in the classroom: Self-report and projective assessments of individual differences in children's perceptions.

Abstract: Two studies examined the significance of children's perceptions of their classroom environment along autonomy versus external control dimensions. Study 1 related a self-report measure of the perceived classroom climate to other self-related constructs. In a sample of 140 elementary children, it was found that the more "origin" the children perceived in their classroom, the higher their perceived self worth, cognitive competence, internal control, and mastery motivation, and the lower their perceived control by unknown sources or powerful others. These relationships were primarily due to individual differences within classrooms rather than average classroom differences. Children also wrote projective stories about an ambiguous classroom scene. Ratings of these stories indicated that, within children's fantasy, origin-like behavior of students was associated with autonomy-oriented teachers and low aggression. Self-report and projective methods converged, particularly for children whose self-reported perceptions were extreme. In a second study (N = 578), relative contributions of classroom and individual difference effects were further examined. Results are discussed in terms of the importance of perceived autonomy and issues in assessment strategies.

A nuclear localization signal within HIV-1 matrix protein that governs infection of non-dividing cells

Abstract: PERMISSIVENESS of the host cell to productive infection by onco-retroviruses is cell-cycle dependent1, and nuclear localization of viral nucleoprotein preintegration complexes will occur only after cells have passed through mitosis2. In contrast, establishment of an integrated provirus after infection by the lentivirus HIV-1 is independent of host cell proliferation3–5. The ability of HIV-1 to replicate in non-dividing cells is partly accounted for by the kary-ophilic properties of the viral preintegration complex which, after virus infection, is actively transported to the host cell nucleus. Here we report that the gag matrix protein of HIV-1 contains a nuclear localization sequence which, when conjugated to a heterologous protein, directs its nuclear import. In addition, HIV-1 mutants containing amino-acid substitutions in this nuclear localization signal integrate and replicate within dividing but not growth-arrested cells, and thus display a phenotype more representative of an onco-retrovirus.

Adjuvant radiotherapy for pathologically advanced prostate cancer: a randomized clinical trial.

Abstract: ContextDespite a stage-shift to earlier cancer stages and lower tumor volumes for prostate cancer, pathologically advanced disease is detected at radical prostatectomy in 38% to 52% of patients. However, the optimal management of these patients after radical prostatectomy is unknown.ObjectiveTo determine whether adjuvant radiotherapy improves metastasis-free survival in patients with stage pT3 N0 M0 prostate cancer.Design, Setting, and PatientsRandomized, prospective, multi-institutional, US clinical trial with enrollment between August 15, 1988, and January 1, 1997 (with database frozen for statistical analysis on September 21, 2005). Patients were 425 men with pathologically advanced prostate cancer who had undergone radical prostatectomy.InterventionMen were randomly assigned to receive 60 to 64 Gy of external beam radiotherapy delivered to the prostatic fossa (n = 214) or usual care plus observation (n = 211).Main Outcome MeasuresPrimary outcome was metastasis-free survival, defined as time to first occurrence of metastatic disease or death due to any cause. Secondary outcomes included prostate-specific antigen (PSA) relapse, recurrence-free survival, overall survival, freedom from hormonal therapy, and postoperative complications.ResultsAmong the 425 men, median follow-up was 10.6 years (interquartile range, 9.2-12.7 years). For metastasis-free survival, 76 (35.5%) of 214 men in the adjuvant radiotherapy group were diagnosed with metastatic disease or died (median metastasis-free estimate, 14.7 years), compared with 91 (43.1%) of 211 (median metastasis-free estimate, 13.2 years) of those in the observation group (hazard ratio [HR], 0.75; 95% CI, 0.55-1.02; P = .06). There were no significant between-group differences for overall survival (71 deaths, median survival of 14.7 years for radiotherapy vs 83 deaths, median survival of 13.8 years for observation; HR, 0.80; 95% CI, 0.58-1.09; P = .16). PSA relapse (median PSA relapse–free survival, 10.3 years for radiotherapy vs 3.1 years for observation; HR, 0.43; 95% CI, 0.31-0.58; P<.001) and disease recurrence (median recurrence-free survival, 13.8 years for radiotherapy vs 9.9 years for observation; HR, 0.62; 95% CI, 0.46-0.82; P = .001) were both significantly reduced with radiotherapy. Adverse effects were more common with radiotherapy vs observation (23.8% vs 11.9%), including rectal complications (3.3% vs 0%), urethral strictures (17.8% vs 9.5%), and total urinary incontinence (6.5% vs 2.8%).ConclusionsIn men who had undergone radical prostatectomy for pathologically advanced prostate cancer, adjuvant radiotherapy resulted in significantly reduced risk of PSA relapse and disease recurrence, although the improvements in metastasis-free survival and overall survival were not statistically significant.Trial Registrationclinicaltrials.gov Identifier: NCT00394511

Improved predictions of secondary structures for RNA.

Abstract: The accuracy of computer predictions of RNA secondary structure from sequence data and free energy parameters has been increased to roughly 70%. Performance is judged by comparison with structures known from phylogenetic analysis. The algorithm also generates suboptimal structures. On average, the best structure within 10% of the lowest free energy contains roughly 90% of phylogenetically known helixes. The algorithm does not include tertiary interactions or pseudoknots and employs a crude model for single-stranded regions. The only favorable interactions are base pairing and stacking of terminal unpaired nucleotides at the ends of helixes. The excellent performance is consistent with these interactions being the primary interactions determining RNA secondary structure.