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Background: Previous studies suggest the rate of positive surgical margin (PSM) after lumpectomy for breast cancer is approximately 20 %. The risk of PSM at time of resection is often a source of fear for patients, driving some to elect to undergo mastectomy. This study describes rates and predictors of positive margins for invasive breast cancers in the National Cancer Database (NCDB)., Materials and Methods: From 2004 to 2013, patients with non-metastatic invasive breast cancers who underwent breast conservation surgery were identified from the NCDB. Patients' demographic, clinical, and facility of treatment characteristics were collected and compared. Per SSO-ASTRO-ASCO criteria, margin negative is defined as no gross or microscopic disease (i.e. no tumor on ink). Bivariate tests and multivariate logistic regression were conducted to identify independent predictors of patients with PSM at the time of resection., Results: A total of 707,798 patients were identified with non-metastatic invasive breast tumors who underwent lumpectomy. Rate of PSM across the entire cohort was 5.02 %. Over time, the rate of PSM decreased significantly from 6.54 % in 2004 to 3.91 % in 2013 (p < 0.001). Pure lobular histology predicted for the highest rate of PSM compared with IDC (8.63 vs 4.55 %; p < 0.001). In adjusted analysis, high grade, non-ductal histology and HER2 amplification were significantly associated with PSM with breast conservation while estrogen and progesterone status were not., Conclusion: This study demonstrates a 5 % risk of PSM at time of breast conservation surgery using a large, modern national database. Patients with invasive lobular and mixed histology have a nearly two-fold risk of PSM compared to invasive ductal cancers. These results provide important data points to help appropriately counsel patients regarding the risk of PSM., Competing Interests: Declaration of competing interest DHB declares research support, speaker honoraria, and consultant work from Novocure Inc. and Varian Medical Systems. No other authors declare conflicts of interest., (Copyright © 2021 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Electromagnetic fields (EMF) permeate the built environment in different forms and come from a number of sources including electrical wiring and devices, wireless communication, 'energy-efficient' lighting, and appliances. It can be present in the indoor environment directly from indoor sources, or can be transmitted through building materials from outside sources. Scientists have identified it as an indoor environmental pollutant or toxin that has ubiquitously plagued developed nations causing a variety of adverse health effects such as sick-building syndrome symptoms, asthma, diabetes, multiple sclerosis, leukemia, electro-hypersensitivity (EHS), behavior disorders, and more. There is currently no international consensus on guidelines and exposure limits. This paper presents the results of 29 EMF field audits in single family residential dwellings located within an urban neighborhood in Toronto (Canada). The following EMF spectra were evaluated: radio frequency, power frequency electric fields, power frequency magnetic fields and high frequency voltage transients. The field audits were conducted in order to provide initial baseline statistics to be used in future studies and in order to be compared to a low-cost EMF reduction design incorporated within the Renovation2050 research house - located within the test neighborhood. The results show the low-cost reduction strategy to be effective, on average reducing exposure by 80% for high-intensity EMF metrics. Research of this nature has not been conducted with relation to the built environment and can be used to spark an industry movement to design for low-exposure to EMF in a residential context., (© 2013.)

We have analyzed the expression pattern and localization of MLE, MLS-1, MSL-2, and histone H4Ac16 during embryogenesis to determine when msl-dependent dosage compensation begins. Maternal MSL-1 and MLE are present in both sexes at fertilization. MSL-2 lacks a maternal component, and male-specific zygotic expression is detectable at the end of blastoderm. During germ band extension, MSL-1, MSL-2, MLE, and histone H4Ac16 display coincident sub-nuclear localization in male embryos. In embryos lacking one of the MSL proteins, the sub-nuclear localization of the other MSLs and of histone H4Ac16 is not detected. We conclude that the MSL proteins associate with the X chromosome and are interdependent since early embryogenesis.

It was found that differentiation of murine erythroleukemia cells can be induced by 5-fluorodeoxyuridine (FudR), amethopterin and alpha-aminoisobutyrate. Each of these compounds is believed to delay the onset of DNA synthesis. Since relief of the FudR block to DNA synthesis by addition of thymidine can increase the number of initiation sites for replication (Taylor, 1977), the effect of various inducers and inhibitors of differentiation of Friend cells upon the relative number of initiation sites for replication and transcription was investigated. Very efficient inducers of hemoglobin synthesis, hexamethylene bisacetamide (HMBA) and dimethylsulfoxide (DMSO), increase the number of initiation sites for transcription and HMBA also increases the number of functional initiation sites for replication. Two other compounds that induce differentiation of Friend cells, low levels of actinomycin D and FudR, did not increase the number of initiation sites for transcription. Compounds that prevent induction of hemoglobin synthesis by HMBA and DMSO include 5-bromodeoxyuridine (BrdU) and novobiocin. Both of these compounds were found to decrease the number of functional initiation sites for transcription and it is known that both compounds reduce the number of initiation sites for replication. The relation between initiation of replication and transcription, and its effect upon differentiation of erythroleukemia cells is discussed.

Macronuclei of Tetrahymena thermophila contain a typical H1 which has been shown to be missing from micronuclei. Instead, micronuclei contain three unique polypeptides, alpha, beta, and gamma, which are associated with linker regions of micronuclear chromatin. In this report polyclonal antibodies raised against macronuclear H1 are shown to react with alpha, beta, and gamma by immunoblotting analyses. This result suggests that these polypeptides share some common structural feature(s). Also consistent with this result is the finding that both macro- and micronuclei in growing and mating cells stain positively with H1 antibodies by in situ indirect immunofluorescence. However, these analyses demonstrate that the level of linker histone is greatly reduced in the micronucleus of starved cells and in young macronuclear anlagen. These results are in agreement with earlier biochemical studies and together provide strong evidence that dramatic changes in linker histone accompany nuclear differentiation (and dedifferentiation) in Tetrahymena.

The polycations (H1 histone and polylysine) and polyanions (heparin and various RNA preparations) stimulate cell division of cultured mammalian cells. The mechanisms by which both polycations (H1 histone and polylysine) and polyanions (heparin and RNA) may increase the rate of cell division are discussed.

Following the demonstration of inhibin activity in the ovary, a search was conducted for such activity in the rabbit placenta. A bioassay was utilized that consisted of 16 hours' incubation of the test substance with cultured rat anterior pituitary cells and determination of gonadotrophins in the recovered media. A crude extract of rabbit placenta had no effect on luteinizing hormone (LH) but a slight and insignificant inhibiting effect on follicle-stimulating hormone (FSH) secretion. Ethanol-extracted low steroid preparation of the rabbit placenta significantly inhibited FSH, but had no effect on LH secretion. On Sephadex G100 chromatography a fraction was identified which had inhibin activity. In a parallel chromatography of human seminal fluid inhibin activity was identified in the same elution volume as that of the rabbit placenta extract. It is suggested that rabbit placenta extract contains a non-steroidal substance that interferes with pituitary secretion of FSH, and that this substance may be inhibin.