931 research outputs found
STK15/Aurora-A expression in primary breast tumors is correlated with nuclear grade by not with prognosis
[[abstract]]BACKGROUND
DNA amplification on chromosome 20q13 is commonly detected in breast carcinoma and is correlated with poor prognosis. STK15 maps to this amplicon. The objective of the current study was to use immunohistochemistry to determine STK15 expression in primary breast tumors. The authors also explored whether STK15 was a prognostic factor for breast carcinoma by comparing the level of STK15 gene expression with clinical parameters that are known prognostic factors for the disease.
METHODS
Archival mastectomy and lumpectomy specimens, randomly selected, were immunohistochemically stained to determine the STK15 gene expression level. The clinical parameters of these same patients were reviewed retrospectively and analyzed for correlations with STK15 expression level, based on a positive-versus-negative scoring system.
RESULTS
Of the 112 human breast tumor specimens analyzed, 26% stained positively for STK15 by immunohistochemistry. Of the tumors, that stained positively 62.1% had a well-to-moderately differentiated nuclear grade. The correlation between STK15 staining and nuclear grade was nearly statistically significant (P = 0.05). No association was found between STK15 staining and tumor size, lymph node status, or hormone receptor status. Analysis of recurrence-free survival and overall survival rates also failed to reveal a statistically significant difference between the two groups.
CONCLUSIONS
STK15 expression by immunohistochemistry was noted in approximately one-fourth of primary breast tumors. STK15 expression was associated with nuclear grade, but no correlation was found between the other clinical parameters evaluated. Furthermore, no differences were found in survival rates when they were analyzed by level of STK15 staining. Cancer 2004;100:12-9. ? 2003 American Cancer Society
Synthesis, Electrochemistry, and Excited-State Properties of Three Ru(II) Quaterpyridine Complexes
The complexes [Ru(qpy)LL′]2+ (qpy = 2,2′:6′,2″:6″,2‴-quaterpyridine), with 1: L = acetonitrile, L′= chloride; 2: L = L′= acetonitrile; and 3: L = L′= vinylpyridine, have been prepared from [Ru(qpy) (Cl)2]. Their absorption spectra in CH3CN exhibit broad metal-to-ligand charge transfer (MLCT) absorptions arising from overlapping 1A1 → 1MLCT transitions. Photoluminescence is not observed at room temperature, but all three are weakly emissive in 4:1 ethanol/methanol glasses at 77 K with broad, featureless emissions observed between 600 and 1000 nm consistent with MLCT phosphorescence. Cyclic voltammograms in CH3CN reveal the expected RuIII/II redox couples. In 0.1 M trifluoroacetic acid (TFA), 1 and 2 undergo aquation to give [RuII(qpy)(OH2)2]2+, as evidenced by the appearance of waves for the couples [RuIII(qpy)(OH2)2]3+/[RuII(qpy)(OH2)2]2+, [RuIV(qpy)(O)(OH2)]2+/[RuIII(qpy)(OH2)2]3+, and [RuVI(qpy)(O)2]2+/[RuIV(qpy)(O)(OH2)]2+ in cyclic voltammograms
Ion atmosphere relaxation controlled electron transfers in cobaltocenium polyether molten salts
A room-temperature redox molten salt for the study of electron transfers in semisolid media, based on combining bis(cyclopentadienyl)cobalt with oligomeric polyether counterions, [Cp2Co](MePEG350SO3), is reported. The transport properties of the new molten salt can be varied (plasticized) by varying the polyether content. The charge transport rate during voltammetric reduction of the ionically conductive [Cp2Co](MePEG350SO3) molten salt exceeds the actual physical diffusivity of [Cp2Co]+ because of rapid [Cp2Co]+/0 electron self-exchanges. The measured [Cp2Co]+/0 electron self-exchange rate constants (kEX) are proportional to the diffusion coefficients (DCION) of the counterions in the melt. The electron-transfer activation barrier energies are also close to those of ionic diffusion but are larger than those derived from optical intervalent charge-transfer results. Additionally, the [Cp2Co]+/0 rate constant results are close to those of dissimilar redox moieties in molten salts where DCION values are similar. All of these characteristics are consistent with the rates of electron transfers of [Cp2Co]+/0 (and the other donor−acceptor pairs) being controlled not by the intrinsic electron-transfer rates but by the rate of relaxation of the ion atmosphere around the reacting pair. In the low driving force regime of mixed-valent concentration gradients, the ion atmosphere relaxation is competitive with electron transfer. The results support the generality of the recently proposed model of ionic atmosphere relaxation control of electron transfers in ionically conductive, semisolid materials
A Phase-Field Model of Spiral Dendritic Growth
Domains of condensed-phase monolayers of chiral molecules exhibit a variety
of interesting nonequilibrium structures when formed via pressurization. To
model these domain patterns, we add a complex field describing the tilt degree
of freedom to an (anisotropic) complex-phase-field solidification model. The
resulting formalism allows for the inclusion of (in general, non-reflection
symmetric) interactions between the tilt, the solid-liquid interface, and the
bond orientation. Simulations demonstrate the ability of the model to exhibit
spiral dendritic growth.Comment: text plus Four postscript figure file
Adoption Issues in DevOps from the Perspective of Continuous Delivery Pipeline
DevOps and Continuous Delivery (CD) are the terms that are always related to each other in Software Delivery and Operation Process area. DevOps introduces a significant agile perspective to deliver the software product in short cycle time that will reduce technical debt that is caused by delay. Continuous Delivery is one of the DevOps' practices that enables software organization to release new features and new products rapidly. However, the correct practices are still in ambiguity to the current CD process. This paper investigates the advantages and limitation of DevOps adoption to improve the CD process. A qualitative web survey has been conducted to identify the DevOps and Continuous Delivery advantages and adoption problems. 13 respondents' feedbacks have been collected and analyzed. Based on the survey, there are four significant DevOps' practices that need to be considered and developed as a proper guideline to introduce to practitioners
Male obesity associated gonadal dysfunction and the role of bariatric surgery
Obesity is an ever growing pandemic and a prevalent problem among men of reproductive age that can both cause and exacerbate male-factor infertility by means of endocrine abnormalities, associated comorbidities, and direct effects on the precision and throughput of spermatogenesis. Robust epidemiologic, clinical, genetic, epigenetic, and preclinical data support these findings. Clinical studies on the impact of medically induced weight loss on serum testosterone concentrations and spermatogenesis is promising but may show differential and unsustainable results. In contrast, literature has demonstrated that weight loss after bariatric surgery is correlated with an increase in serum testosterone concentrations that is superior than that obtained with only lifestyle modifications, supporting a further metabolic benefit from surgery that may be specific to the male reproductive system. The data on sperm and semen parameters is controversial to date. Emerging evidence in the burgeoning field of genetics and epigenetics has demonstrated that paternal obesity can affect offspring metabolic and reproductive phenotypes by means of epigenetic reprogramming of spermatogonial stem cells. Understanding the impact of this reprogramming is critical to a comprehensive view of the impact of obesity on subsequent generations. Furthermore, conveying the potential impact of these lifestyle changes on future progeny can serve as a powerful tool for obese men to modify their behavior. Healthcare professionals treating male infertility and obesity need to adapt their practice to assimilate these new findings to better counsel men about the importance of paternal preconception health and the impact of novel non-medical therapeutic interventions. Herein, we summarize the pathophysiology of obesity on the male reproductive system and emerging evidence regarding the potential role of bariatric surgery as treatment of male obesity-associated gonadal dysfunction
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A PAX5-OCT4-PRDM1 developmental switch specifies human primordial germ cells.
Dysregulation of genetic pathways during human germ cell development leads to infertility. Here, we analysed bona fide human primordial germ cells (hPGCs) to probe the developmental genetics of human germ cell specification and differentiation. We examined the distribution of OCT4 occupancy in hPGCs relative to human embryonic stem cells (hESCs). We demonstrated that development, from pluripotent stem cells to germ cells, is driven by switching partners with OCT4 from SOX2 to PAX5 and PRDM1. Gain- and loss-of-function studies revealed that PAX5 encodes a critical regulator of hPGC development. Moreover, an epistasis analysis indicated that PAX5 acts upstream of OCT4 and PRDM1. The PAX5-OCT4-PRDM1 proteins form a core transcriptional network that activates germline and represses somatic programmes during human germ cell differentiation. These findings illustrate the power of combined genome editing, cell differentiation and engraftment for probing human developmental genetics that have historically been difficult to study
Large introns in relation to alternative splicing and gene evolution: a case study of Drosophila bruno-3
Background:
Alternative splicing (AS) of maturing mRNA can generate structurally and functionally distinct transcripts from the same gene. Recent bioinformatic analyses of available genome databases inferred a positive correlation between intron length and AS. To study the interplay between intron length and AS empirically and in more detail, we analyzed the diversity of alternatively spliced transcripts (ASTs) in the Drosophila RNA-binding Bruno-3 (Bru-3) gene. This gene was known to encode thirteen exons separated by introns of diverse sizes, ranging from 71 to 41,973 nucleotides in D. melanogaster. Although Bru-3's structure is expected to be conducive to AS, only two ASTs of this gene were previously described.
Results:
Cloning of RT-PCR products of the entire ORF from four species representing three diverged Drosophila lineages provided an evolutionary perspective, high sensitivity, and long-range contiguity of splice choices currently unattainable by high-throughput methods. Consequently, we identified three new exons, a new exon fragment and thirty-three previously unknown ASTs of Bru-3. All exon-skipping events in the gene were mapped to the exons surrounded by introns of at least 800 nucleotides, whereas exons split by introns of less than 250 nucleotides were always spliced contiguously in mRNA. Cases of exon loss and creation during Bru-3 evolution in Drosophila were also localized within large introns. Notably, we identified a true de novo exon gain: exon 8 was created along the lineage of the obscura group from intronic sequence between cryptic splice sites conserved among all Drosophila species surveyed. Exon 8 was included in mature mRNA by the species representing all the major branches of the obscura group. To our knowledge, the origin of exon 8 is the first documented case of exonization of intronic sequence outside vertebrates.
Conclusion:
We found that large introns can promote AS via exon-skipping and exon turnover during evolution likely due to frequent errors in their removal from maturing mRNA. Large introns could be a reservoir of genetic diversity, because they have a greater number of mutable sites than short introns. Taken together, gene structure can constrain and/or promote gene evolution
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