Modulation of proteostasis counteracts oxidative stress and affects DNA base excision repair capacity in ATM-deficient cells.

PubMed

Poletto, Mattia; Yang, Di; Fletcher, Sally C; Vendrell, Iolanda; Fischer, Roman; Legrand, Arnaud J; Dianov, Grigory L

2017-09-29

Ataxia telangiectasia (A-T) is a syndrome associated with loss of ATM protein function. Neurodegeneration and cancer predisposition, both hallmarks of A-T, are likely to emerge as a consequence of the persistent oxidative stress and DNA damage observed in this disease. Surprisingly however, despite these severe features, a lack of functional ATM is still compatible with early life, suggesting that adaptation mechanisms contributing to cell survival must be in place. Here we address this gap in our knowledge by analysing the process of human fibroblast adaptation to the lack of ATM. We identify profound rearrangement in cellular proteostasis occurring very early on after loss of ATM in order to counter protein damage originating from oxidative stress. Change in proteostasis, however, is not without repercussions. Modulating protein turnover in ATM-depleted cells also has an adverse effect on the DNA base excision repair pathway, the major DNA repair system that deals with oxidative DNA damage. As a consequence, the burden of unrepaired endogenous DNA lesions intensifies, progressively leading to genomic instability. Our study provides a glimpse at the cellular consequences of loss of ATM and highlights a previously overlooked role for proteostasis in maintaining cell survival in the absence of ATM function. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

Oxidative DNA damage background estimated by a system model of base excision repair

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sokhansanj, B A; Wilson, III, D M

Human DNA can be damaged by natural metabolism through free radical production. It has been suggested that the equilibrium between innate damage and cellular DNA repair results in an oxidative DNA damage background that potentially contributes to disease and aging. Efforts to quantitatively characterize the human oxidative DNA damage background level based on measuring 8-oxoguanine lesions as a biomarker have led to estimates varying over 3-4 orders of magnitude, depending on the method of measurement. We applied a previously developed and validated quantitative pathway model of human DNA base excision repair, integrating experimentally determined endogenous damage rates and model parametersmore » from multiple sources. Our estimates of at most 100 8-oxoguanine lesions per cell are consistent with the low end of data from biochemical and cell biology experiments, a result robust to model limitations and parameter variation. Our results show the power of quantitative system modeling to interpret composite experimental data and make biologically and physiologically relevant predictions for complex human DNA repair pathway mechanisms and capacity.« less

Base excision repair, the redox environment and therapeutic implications.

PubMed

Storr, S J; Woolston, C M; Martin, S G

2012-01-01

Control of redox homeostasis is crucial for a number of cellular processes with deregulation leading to a number of serious consequences including oxidative damage such induction of DNA base lesions. The DNA lesions caused by oxidative damage are principally repaired by the base excision repair (BER) pathway. Pharmacological inhibition of BER is becoming an increasingly active area of research with the emergence of PARP inhibitors in cancer therapy. The redox status of the cell is modulated by a number of systems, including a large number of anti-oxidant enzymes who function in the control of superoxide and hydrogen peroxide, and ultimately in the release of the damaging hydroxyl radical. Here we provide an overview of reactive oxygen species (ROS) production and its modulation by antioxidant enzymes. The review also discusses the effect of ROS on the BER pathway, particularly in relation to cancer. Finally, as the modulation of the redox environment is of interest in cancer therapy, with certain agents having the potential to reverse chemo- and radiotherapy resistance or treat therapy related toxicity, we discuss redox modulating agents currently under development.

Cellular Angiofibroma of the Nasopharynx.

PubMed

Erdur, Zülküf Burak; Yener, Haydar Murat; Yilmaz, Mehmet; Karaaltin, Ayşegül Batioğlu; Inan, Hakki Caner; Alaskarov, Elvin; Gozen, Emine Deniz

2017-11-01

Angiofibroma is a common tumor of the nasopharynx region but cellular type is extremely rare in head and neck. A 13-year-old boy presented with frequent epistaxis and nasal obstruction persisting for 6 months. According to the clinical symptoms and imaging studies juvenile angiofibroma was suspected. Following angiographic embolization total excision of the lesion by midfacial degloving approach was performed. Histological examination revealed that the tumor consisted of staghorn blood vessels and irregular fibrous stroma. Stellate fibroblasts with small pyknotic to large vesicular nuclei were seen in a highly cellular stroma. These findings identified cellular angiofibroma mimicking juvenile angiofibroma. This article is about a very rare patient of cellular angiofibroma of nasopharynx.

Direct and indirect roles of RECQL4 in modulating base excision repair capacity

PubMed Central

Schurman, Shepherd H.; Hedayati, Mohammad; Wang, ZhengMing; Singh, Dharmendra K.; Speina, Elzbieta; Zhang, Yongqing; Becker, Kevin; Macris, Margaret; Sung, Patrick; Wilson, David M.; Croteau, Deborah L.; Bohr, Vilhelm A.

2009-01-01

RECQL4 is a human RecQ helicase which is mutated in approximately two-thirds of individuals with Rothmund–Thomson syndrome (RTS), a disease characterized at the cellular level by chromosomal instability. BLM and WRN are also human RecQ helicases, which are mutated in Bloom and Werner's syndrome, respectively, and associated with chromosomal instability as well as premature aging. Here we show that primary RTS and RECQL4 siRNA knockdown human fibroblasts accumulate more H2O2-induced DNA strand breaks than control cells, suggesting that RECQL4 may stimulate repair of H2O2-induced DNA damage. RTS primary fibroblasts also accumulate more XRCC1 foci than control cells in response to endogenous or induced oxidative stress and have a high basal level of endogenous formamidopyrimidines. In cells treated with H2O2, RECQL4 co-localizes with APE1, and FEN1, key participants in base excision repair. Biochemical experiments indicate that RECQL4 specifically stimulates the apurinic endonuclease activity of APE1, the DNA strand displacement activity of DNA polymerase β, and incision of a 1- or 10-nucleotide flap DNA substrate by Flap Endonuclease I. Additionally, RTS cells display an upregulation of BER pathway genes and fail to respond like normal cells to oxidative stress. The data herein support a model in which RECQL4 regulates both directly and indirectly base excision repair capacity. PMID:19567405

Enhancement of UV-induced nucleotide excision repair activity upon forskolin treatment is cell growth-dependent.

PubMed

Lee, Jeong-Min; Park, Jeong-Min; Kang, Tae-Hong

2016-10-01

Forskolin (FSK), an adenylyl cyclase activator, has recently been shown to enhance nucleotide excision repair (NER) upon UV exposure. However, our study revealed that this effect was detected in human skin epithelial ARPE19 cells only in growing cells, but not in non-cycling cells. When the cells were grown at low density (70% confluence), FSK was capable of stimulating cAMP responsive element binding (CREB) phosphorylation, a marker for FSK-stimulated PKA activation, and resulted in a significant increase of NER activity compared to control treatment. However, cells grown under 100% confluent conditions showed neither FSK-induced CREB phosphorylation nor the resulting NER enhancement. These findings indicate that cellular growth is critical for FSK-induced NER enhancement and suggest that cellular growth conditions should be considered as a variable while evaluating a reagent's pharmacotherapeutic efficacy. [BMB Reports 2016; 49(10): 566-571].

Cellular Angiofibroma of Oral Mucosa: Report of Two Cases

PubMed Central

2009-01-01

Cellular angiofibroma is a benign vascular neoplasm that typically arises in the vulva, perineal, and paratesticular region. Microscopically the lesions exhibit multiple small, non-dilated capillary channels, many of which contain erythrocytes. The endothelial lining cells are prominent, with monomorphic oval nuclei. Interposed among the vessels are both delicate and mature collagen fibers with fibroblastic hypercellularity that is variable in older lesions where sclerosis is prominent. The lesions usually do not recur following simple excision. Recent evidence indicates that cellular angiofibromas may be cytogenetically related to spindle cell lipoma. This represents the first reported instances of cellular angiofibroma in the oral cavity. PMID:19644547

Spectral grading and Gleason grading of malignant prostate tissue using Stokes shift spectra

NASA Astrophysics Data System (ADS)

Al Salhi, M.; Masilamani, V.; Rabah, D.; Farhat, K.; Liu, C. H.; Pu, Y.; Alfano, R. R.

2012-01-01

Gleason score is the most common method of grading the virulence of prostate malignancy and is based on the pathological assessment of morphology of cellular matrix. Since this involves the excision of the tissue, we are working on a new, minimally invasive, non contact, procedure of spectral diagnosis of prostate malignancy. In this preliminary in vitro study reported here, we have analyzed 27 tissue samples (normal control =7: benign=8: malignant =12) by Stokes' shift spectra (SSS) to establish a one- to- one correlation between spectral grading and Gleason grading.

Confocal reflectance microscopy of basal cell cancers ex vivo: progress toward enhancing contrast and detectability of nuclei relative to dermis

NASA Astrophysics Data System (ADS)

Patel, Yogesh G.; Nehal, Kishwer S.; Halpern, Allan C.; Rajadhyaksha, Milind

2005-04-01

Mohs surgery is a staged procedure for microscopically excising basal cell carcinomas (BCCs) while preserving the surrounding normal skin. Serial excisions are performed with each excision being guided by examination of the frozen histology. Mohs surgery is a meticulous and time-consuming (15-45 minutes per excision) procedure requiring several (2-20) excisions and frozen histology prepared for each excision. Real-time confocal reflectance microscopy may make Mohs surgery more efficient by enabling rapid detection of BCCs directly in fresh, unprocessed excisions, and thereby possibly avoiding frozen histology. As previously reported, we are developing an acetowhitening-and-cross polarized method to detect BCCs with a confocal reflectance microscope. Acetowhitening compacts the chromatin within the nucleus, increasing nuclear backscatter, and brightening the nuclei in the confocal images of the tissue. Our experiments to optimize acetowhitening, using acetic acid concentrations from 1% to 30% and treatment times from 30 seconds to 5 minutes, show that a minimum concentration of 2% with minimum washing time of 2 minutes is required for enhancing nuclear morphology. Increased depolarization is observed within the compacted chromatin relative to the surrounding collagen, and imaging in brightfield or crossed polarization brightens or darkens the cellular cytoplasm and birefringent dermis; thus, we may potentially vary nuclear/cytoplasm and nuclear/dermis contrast. Images are collected, oriented, and tiled to create mosaics and sub-mosaics to view large excisions at variable 2X - 10X magnifications. To create and display mosaics, adequate pixelation relative to resolution must be maintained and precise mechanical fixturing is necessary to control tilt, sag, flattening and stability of the excised tissue specimen.

Ubiquitylation-dependent regulation of NEIL1 by Mule and TRIM26 is required for the cellular DNA damage response.

PubMed

Edmonds, Matthew J; Carter, Rachel J; Nickson, Catherine M; Williams, Sarah C; Parsons, Jason L

2017-01-25

Endonuclease VIII-like protein 1 (NEIL1) is a DNA glycosylase involved in initiating the base excision repair pathway, the major cellular mechanism for repairing DNA base damage. Here, we have purified the major E3 ubiquitin ligases from human cells responsible for regulation of NEIL1 by ubiquitylation. Interestingly, we have identified two enzymes that catalyse NEIL1 polyubiquitylation, Mcl-1 ubiquitin ligase E3 (Mule) and tripartite motif 26 (TRIM26). We demonstrate that these enzymes are capable of polyubiquitylating NEIL1 in vitro, and that both catalyse ubiquitylation of NEIL1 within the same C-terminal lysine residues. An siRNA-mediated knockdown of Mule or TRIM26 leads to stabilisation of NEIL1, demonstrating that these enzymes are important in regulating cellular NEIL1 steady state protein levels. Similarly, a mutant NEIL1 protein lacking residues for ubiquitylation is more stable than the wild type protein in vivo We also demonstrate that cellular NEIL1 protein is induced in response to ionising radiation (IR), although this occurs specifically in a Mule-dependent manner. Finally we show that stabilisation of NEIL1, particularly following TRIM26 siRNA, contributes to cellular resistance to IR. This highlights the importance of Mule and TRIM26 in maintaining steady state levels of NEIL1, but also those required for the cellular DNA damage response. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

Resistance to Nucleotide Excision Repair of Bulky Guanine Adducts Opposite Abasic Sites in DNA Duplexes and Relationships between Structure and Function

PubMed Central

Liu, Zhi; Ding, Shuang; Kropachev, Konstantin; Lei, Jia; Amin, Shantu; Broyde, Suse; Geacintov, Nicholas E.

2015-01-01

The nucleotide excision repair of certain bulky DNA lesions is abrogated in some specific non-canonical DNA base sequence contexts, while the removal of the same lesions by the nucleotide excision repair mechanism is efficient in duplexes in which all base pairs are complementary. Here we show that the nucleotide excision repair activity in human cell extracts is moderate-to-high in the case of two stereoisomeric DNA lesions derived from the pro-carcinogen benzo[a]pyrene (cis- and trans-B[a]P-N 2-dG adducts) in a normal DNA duplex. By contrast, the nucleotide excision repair activity is completely abrogated when the canonical cytosine base opposite the B[a]P-dG adducts is replaced by an abasic site in duplex DNA. However, base excision repair of the abasic site persists. In order to understand the structural origins of these striking phenomena, we used NMR and molecular spectroscopy techniques to evaluate the conformational features of 11mer DNA duplexes containing these B[a]P-dG lesions opposite abasic sites. Our results show that in these duplexes containing the clustered lesions, both B[a]P-dG adducts adopt base-displaced intercalated conformations, with the B[a]P aromatic rings intercalated into the DNA helix. To explain the persistence of base excision repair in the face of the opposed bulky B[a]P ring system, molecular modeling results suggest how the APE1 base excision repair endonuclease, that excises abasic lesions, can bind productively even with the trans-B[a]P-dG positioned opposite the abasic site. We hypothesize that the nucleotide excision repair resistance is fostered by local B[a]P residue—DNA base stacking interactions at the abasic sites, that are facilitated by the absence of the cytosine partner base in the complementary strand. More broadly, this study sets the stage for elucidating the interplay between base excision and nucleotide excision repair in processing different types of clustered DNA lesions that are substrates of nucleotide excision repair or base excision repair mechanisms. PMID:26340000

Oxidatively Generated Guanine(C8)-Thymine(N3) Intrastrand Cross-links in Double-stranded DNA Are Repaired by Base Excision Repair Pathways.

PubMed

Talhaoui, Ibtissam; Shafirovich, Vladimir; Liu, Zhi; Saint-Pierre, Christine; Akishev, Zhiger; Matkarimov, Bakhyt T; Gasparutto, Didier; Geacintov, Nicholas E; Saparbaev, Murat

2015-06-05

Oxidatively generated guanine radical cations in DNA can undergo various nucleophilic reactions including the formation of C8-guanine cross-links with adjacent or nearby N3-thymines in DNA in the presence of O2. The G*[C8-N3]T* lesions have been identified in the DNA of human cells exposed to oxidative stress, and are most likely genotoxic if not removed by cellular defense mechanisms. It has been shown that the G*[C8-N3]T* lesions are substrates of nucleotide excision repair in human cell extracts. Cleavage at the sites of the lesions was also observed but not further investigated (Ding et al. (2012) Nucleic Acids Res. 40, 2506-2517). Using a panel of eukaryotic and prokaryotic bifunctional DNA glycosylases/lyases (NEIL1, Nei, Fpg, Nth, and NTH1) and apurinic/apyrimidinic (AP) endonucleases (Apn1, APE1, and Nfo), the analysis of cleavage fragments by PAGE and MALDI-TOF/MS show that the G*[C8-N3]T* lesions in 17-mer duplexes are incised on either side of G*, that none of the recovered cleavage fragments contain G*, and that T* is converted to a normal T in the 3'-fragment cleavage products. The abilities of the DNA glycosylases to incise the DNA strand adjacent to G*, while this base is initially cross-linked with T*, is a surprising observation and an indication of the versatility of these base excision repair proteins. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Oxidatively Generated Guanine(C8)-Thymine(N3) Intrastrand Cross-links in Double-stranded DNA Are Repaired by Base Excision Repair Pathways*

PubMed Central

Talhaoui, Ibtissam; Shafirovich, Vladimir; Liu, Zhi; Saint-Pierre, Christine; Akishev, Zhiger; Matkarimov, Bakhyt T.; Gasparutto, Didier; Geacintov, Nicholas E.; Saparbaev, Murat

2015-01-01

Oxidatively generated guanine radical cations in DNA can undergo various nucleophilic reactions including the formation of C8-guanine cross-links with adjacent or nearby N3-thymines in DNA in the presence of O2. The G*[C8-N3]T* lesions have been identified in the DNA of human cells exposed to oxidative stress, and are most likely genotoxic if not removed by cellular defense mechanisms. It has been shown that the G*[C8-N3]T* lesions are substrates of nucleotide excision repair in human cell extracts. Cleavage at the sites of the lesions was also observed but not further investigated (Ding et al. (2012) Nucleic Acids Res. 40, 2506–2517). Using a panel of eukaryotic and prokaryotic bifunctional DNA glycosylases/lyases (NEIL1, Nei, Fpg, Nth, and NTH1) and apurinic/apyrimidinic (AP) endonucleases (Apn1, APE1, and Nfo), the analysis of cleavage fragments by PAGE and MALDI-TOF/MS show that the G*[C8-N3]T* lesions in 17-mer duplexes are incised on either side of G*, that none of the recovered cleavage fragments contain G*, and that T* is converted to a normal T in the 3′-fragment cleavage products. The abilities of the DNA glycosylases to incise the DNA strand adjacent to G*, while this base is initially cross-linked with T*, is a surprising observation and an indication of the versatility of these base excision repair proteins. PMID:25903131

Formation and Repair of Tobacco Carcinogen-Derived Bulky DNA Adducts

DOE PAGES

Hang, Bo

2010-01-01

DNA adducts play a central role in chemical carcinogenesis. The analysis of formation and repair of smoking-related DNA adducts remains particularly challenging as both smokers and nonsmokers exposed to smoke are repetitively under attack from complex mixtures of carcinogens such as polycyclic aromatic hydrocarbons and N -nitrosamines. The bulky DNA adducts, which usually have complex structure, are particularly important because of their biological relevance. Several known cellular DNA repair pathways have been known to operate in human cells on specific types of bulky DNA adducts, for example, nucleotide excision repair, base excision repair, and direct reversal involving O 6 -alkylguaninemore » DNA alkyltransferase or AlkB homologs. Understanding the mechanisms of adduct formation and repair processes is critical for the assessment of cancer risk resulting from exposure to cigarette smoke, and ultimately for developing strategies of cancer prevention. This paper highlights the recent progress made in the areas concerning formation and repair of bulky DNA adducts in the context of tobacco carcinogen-associated genotoxic and carcinogenic effects.« less

A Giant Vulvar Mass: A Case Study of Cellular Angiofibroma

PubMed Central

Aydın, Ümit; Terzi, Hasan; Turkay, Ünal; Eruyar, Ahmet Tuğrul; Kale, Ahmet

2016-01-01

Cellular angiofibroma is a mesenchymal tumor that affects both genders. Nucci et al. first described it in 1997. Cellular angiofibroma is generally a small and asymptomatic mass that primarily arises in the vulvar-vaginal region, although rare cases have been reported in the pelvic and extrapelvic regions. It affects women most often during the fifth decade of life. The treatment requires simple local excision due to low local recurrence and no chance of metastasization. The current study presents a case of angiofibroma in the vulvar region that measured approximately 20 cm. PMID:27293929

Rapid Screening of Cancer Margins in Tissue with Multimodal Confocal Microscopy

PubMed Central

Gareau, Daniel S.; Jeon, Hana; Nehal, Kishwer S.; Rajadhyaksha, Milind

2012-01-01

Background Complete and accurate excision of cancer is guided by the examination of histopathology. However, preparation of histopathology is labor intensive and slow, leading to insufficient sampling of tissue and incomplete and/or inaccurate excision of margins. We demonstrate the potential utility of multimodal confocal mosaicing microscopy for rapid screening of cancer margins, directly in fresh surgical excisions, without the need for conventional embedding, sectioning or processing. Materials/Methods A multimodal confocal mosaicing microscope was developed to image basal cell carcinoma margins in surgical skin excisions, with resolution that shows nuclear detail. Multimodal contrast is with fluorescence for imaging nuclei and reflectance for cellular cytoplasm and dermal collagen. Thirtyfive excisions of basal cell carcinomas from Mohs surgery were imaged, and the mosaics analyzed by comparison to the corresponding frozen pathology. Results Confocal mosaics are produced in about 9 minutes, displaying tissue in fields-of-view of 12 mm with 2X magnification. A digital staining algorithm transforms black and white contrast to purple and pink, which simulates the appearance of standard histopathology. Mosaicing enables rapid digital screening, which mimics the examination of histopathology. Conclusions Multimodal confocal mosaicing microscopy offers a technology platform to potentially enable real-time pathology at the bedside. The imaging may serve as an adjunct to conventional histopathology, to expedite screening of margins and guide surgery toward more complete and accurate excision of cancer. PMID:22721570

Alar base reduction: the boomerang-shaped excision.

PubMed

Foda, Hossam M T

2011-04-01

A boomerang-shaped alar base excision is described to narrow the nasal base and correct the excessive alar flare. The boomerang excision combined the external alar wedge resection with an internal vestibular floor excision. The internal excision was inclined 30 to 45 degrees laterally to form the inner limb of the boomerang. The study included 46 patients presenting with wide nasal base and excessive alar flaring. All cases were followed for a mean period of 18 months (range, 8 to 36 months). The laterally oriented vestibular floor excision allowed for maximum preservation of the natural curvature of the alar rim where it meets the nostril floor and upon its closure resulted in a considerable medialization of alar lobule, which significantly reduced the amount of alar flare and the amount of external alar excision needed. This external alar excision measured, on average, 3.8 mm (range, 2 to 8 mm), which is significantly less than that needed when a standard vertical internal excision was used ( P < 0.0001). Such conservative external excisions eliminated the risk of obliterating the natural alar-facial crease, which did not occur in any of our cases. No cases of postoperative bleeding, infection, or vestibular stenosis were encountered. Keloid or hypertrophic scar formation was not encountered; however, dermabrasion of the scars was needed in three (6.5%) cases to eliminate apparent suture track marks. The boomerang alar base excision proved to be a safe and effective technique for narrowing the nasal base and elimination of the excessive flaring and resulted in a natural, well-proportioned nasal base with no obvious scarring. © Thieme Medical Publishers.

Formation and Repair of Mismatches Containing Ribonucleotides and Oxidized Bases at Repeated DNA Sequences*

PubMed Central

Cilli, Piera; Minoprio, Anna; Bossa, Cecilia; Bignami, Margherita; Mazzei, Filomena

2015-01-01

The cellular pool of ribonucleotide triphosphates (rNTPs) is higher than that of deoxyribonucleotide triphosphates. To ensure genome stability, DNA polymerases must discriminate against rNTPs and incorporated ribonucleotides must be removed by ribonucleotide excision repair (RER). We investigated DNA polymerase β (POL β) capacity to incorporate ribonucleotides into trinucleotide repeated DNA sequences and the efficiency of base excision repair (BER) and RER enzymes (OGG1, MUTYH, and RNase H2) when presented with an incorrect sugar and an oxidized base. POL β incorporated rAMP and rCMP opposite 7,8-dihydro-8-oxoguanine (8-oxodG) and extended both mispairs. In addition, POL β was able to insert and elongate an oxidized rGMP when paired with dA. We show that RNase H2 always preserves the capacity to remove a single ribonucleotide when paired to an oxidized base or to incise an oxidized ribonucleotide in a DNA duplex. In contrast, BER activity is affected by the presence of a ribonucleotide opposite an 8-oxodG. In particular, MUTYH activity on 8-oxodG:rA mispairs is fully inhibited, although its binding capacity is retained. This results in the reduction of RNase H2 incision capability of this substrate. Thus complex mispairs formed by an oxidized base and a ribonucleotide can compromise BER and RER in repeated sequences. PMID:26338705

Highly Precise and Developmentally Programmed Genome Assembly in Paramecium Requires Ligase IV–Dependent End Joining

PubMed Central

Marmignon, Antoine; Ku, Michael; Silve, Aude; Meyer, Eric; Forney, James D.; Malinsky, Sophie; Bétermier, Mireille

2011-01-01

During the sexual cycle of the ciliate Paramecium, assembly of the somatic genome includes the precise excision of tens of thousands of short, non-coding germline sequences (Internal Eliminated Sequences or IESs), each one flanked by two TA dinucleotides. It has been reported previously that these genome rearrangements are initiated by the introduction of developmentally programmed DNA double-strand breaks (DSBs), which depend on the domesticated transposase PiggyMac. These DSBs all exhibit a characteristic geometry, with 4-base 5′ overhangs centered on the conserved TA, and may readily align and undergo ligation with minimal processing. However, the molecular steps and actors involved in the final and precise assembly of somatic genes have remained unknown. We demonstrate here that Ligase IV and Xrcc4p, core components of the non-homologous end-joining pathway (NHEJ), are required both for the repair of IES excision sites and for the circularization of excised IESs. The transcription of LIG4 and XRCC4 is induced early during the sexual cycle and a Lig4p-GFP fusion protein accumulates in the developing somatic nucleus by the time IES excision takes place. RNAi–mediated silencing of either gene results in the persistence of free broken DNA ends, apparently protected against extensive resection. At the nucleotide level, controlled removal of the 5′-terminal nucleotide occurs normally in LIG4-silenced cells, while nucleotide addition to the 3′ ends of the breaks is blocked, together with the final joining step, indicative of a coupling between NHEJ polymerase and ligase activities. Taken together, our data indicate that IES excision is a “cut-and-close” mechanism, which involves the introduction of initiating double-strand cleavages at both ends of each IES, followed by DSB repair via highly precise end joining. This work broadens our current view on how the cellular NHEJ pathway has cooperated with domesticated transposases for the emergence of new mechanisms involved in genome dynamics. PMID:21533177

Highly precise and developmentally programmed genome assembly in Paramecium requires ligase IV-dependent end joining.

PubMed

Kapusta, Aurélie; Matsuda, Atsushi; Marmignon, Antoine; Ku, Michael; Silve, Aude; Meyer, Eric; Forney, James D; Malinsky, Sophie; Bétermier, Mireille

2011-04-01

During the sexual cycle of the ciliate Paramecium, assembly of the somatic genome includes the precise excision of tens of thousands of short, non-coding germline sequences (Internal Eliminated Sequences or IESs), each one flanked by two TA dinucleotides. It has been reported previously that these genome rearrangements are initiated by the introduction of developmentally programmed DNA double-strand breaks (DSBs), which depend on the domesticated transposase PiggyMac. These DSBs all exhibit a characteristic geometry, with 4-base 5' overhangs centered on the conserved TA, and may readily align and undergo ligation with minimal processing. However, the molecular steps and actors involved in the final and precise assembly of somatic genes have remained unknown. We demonstrate here that Ligase IV and Xrcc4p, core components of the non-homologous end-joining pathway (NHEJ), are required both for the repair of IES excision sites and for the circularization of excised IESs. The transcription of LIG4 and XRCC4 is induced early during the sexual cycle and a Lig4p-GFP fusion protein accumulates in the developing somatic nucleus by the time IES excision takes place. RNAi-mediated silencing of either gene results in the persistence of free broken DNA ends, apparently protected against extensive resection. At the nucleotide level, controlled removal of the 5'-terminal nucleotide occurs normally in LIG4-silenced cells, while nucleotide addition to the 3' ends of the breaks is blocked, together with the final joining step, indicative of a coupling between NHEJ polymerase and ligase activities. Taken together, our data indicate that IES excision is a "cut-and-close" mechanism, which involves the introduction of initiating double-strand cleavages at both ends of each IES, followed by DSB repair via highly precise end joining. This work broadens our current view on how the cellular NHEJ pathway has cooperated with domesticated transposases for the emergence of new mechanisms involved in genome dynamics.

Imaging of oxygenation in 3D tissue models with multi-modal phosphorescent probes

NASA Astrophysics Data System (ADS)

Papkovsky, Dmitri B.; Dmitriev, Ruslan I.; Borisov, Sergei

2015-03-01

Cell-penetrating phosphorescence based probes allow real-time, high-resolution imaging of O2 concentration in respiring cells and 3D tissue models. We have developed a panel of such probes, small molecule and nanoparticle structures, which have different spectral characteristics, cell penetrating and tissue staining behavior. The probes are compatible with conventional live cell imaging platforms and can be used in different detection modalities, including ratiometric intensity and PLIM (Phosphorescence Lifetime IMaging) under one- or two-photon excitation. Analytical performance of these probes and utility of the O2 imaging method have been demonstrated with different types of samples: 2D cell cultures, multi-cellular spheroids from cancer cell lines and primary neurons, excised slices from mouse brain, colon and bladder tissue, and live animals. They are particularly useful for hypoxia research, ex-vivo studies of tissue physiology, cell metabolism, cancer, inflammation, and multiplexing with many conventional fluorophors and markers of cellular function.

Monitoring regulation of DNA repair activities of cultured cells in-gel using the comet assay

PubMed Central

Nickson, Catherine M.; Parsons, Jason L.

2014-01-01

Base excision repair (BER) is the predominant cellular mechanism by which human cells repair DNA base damage, sites of base loss, and DNA single strand breaks of various complexity, that are generated in their thousands in every human cell per day as a consequence of cellular metabolism and exogenous agents, including ionizing radiation. Over the last three decades the comet assay has been employed in scientific research to examine the cellular response to these types of DNA damage in cultured cells, therefore revealing the efficiency and capacity of BER. We have recently pioneered new research demonstrating an important role for post-translational modifications (particularly ubiquitylation) in the regulation of cellular levels of BER proteins, and that subtle changes (∼20–50%) in protein levels following siRNA knockdown of E3 ubiquitin ligases or deubiquitylation enzymes can manifest in significant changes in DNA repair capacity monitored using the comet assay. For example, we have shown that the E3 ubiquitin ligase Mule, the tumor suppressor protein ARF, and the deubiquitylation enzyme USP47 modulate DNA repair by controlling cellular levels of DNA polymerase β, and also that polynucleotide kinase phosphatase levels are controlled by ATM-dependant phosphorylation and Cul4A–DDB1–STRAP-dependent ubiquitylation. In these studies we employed a modification of the comet assay whereby cultured cells, following DNA damage treatment, are embedded in agarose and allowed to repair in-gel prior to lysis and electrophoresis. Whilst this method does have its limitations, it avoids the extensive cell culture-based processing associated with the traditional approach using attached cells and also allows for the examination of much more precise DNA repair kinetics. In this review we will describe, using this modified comet assay, our accumulating evidence that ubiquitylation-dependant regulation of BER proteins has important consequences for overall cellular DNA repair capacity. PMID:25076968

Nuclear organization of nucleotide excision repair is mediated by RING1B dependent H2A-ubiquitylation

PubMed Central

Chitale, Shalaka; Richly, Holger

2017-01-01

One of the major cellular DNA repair pathways is nucleotide excision repair (NER). It is the primary pathway for repair of various DNA lesions caused by exposure to ultraviolet (UV) light, such as cyclobutane pyrimidine dimers (CPDs) and 6-4 photoproducts. Although lesion-containing DNA associates with the nuclear matrix after UV irradiation it is still not understood how nuclear organization affects NER. Analyzing unscheduled DNA synthesis (UDS) indicates that NER preferentially occurs in specific nuclear areas, viz the nucleolus. Upon inducing localized damage, we observe migration of damaged DNA towards the nucleolus. Employing a LacR-based tethering system we demonstrate that H2A-ubiquitylation via the UV-RING1B complex localizes chromatin close to the nucleolus. We further show that the H2A-ubiquitin binding protein ZRF1 resides in the nucleolus, and that it anchors ubiquitylated chromatin along with XPC. Our data thus provide insight into the sub-nuclear organization of NER and reveal a novel role for histone H2A-ubiquitylation. PMID:28416769

Formation and Repair of Mismatches Containing Ribonucleotides and Oxidized Bases at Repeated DNA Sequences.

PubMed

Cilli, Piera; Minoprio, Anna; Bossa, Cecilia; Bignami, Margherita; Mazzei, Filomena

2015-10-23

The cellular pool of ribonucleotide triphosphates (rNTPs) is higher than that of deoxyribonucleotide triphosphates. To ensure genome stability, DNA polymerases must discriminate against rNTPs and incorporated ribonucleotides must be removed by ribonucleotide excision repair (RER). We investigated DNA polymerase β (POL β) capacity to incorporate ribonucleotides into trinucleotide repeated DNA sequences and the efficiency of base excision repair (BER) and RER enzymes (OGG1, MUTYH, and RNase H2) when presented with an incorrect sugar and an oxidized base. POL β incorporated rAMP and rCMP opposite 7,8-dihydro-8-oxoguanine (8-oxodG) and extended both mispairs. In addition, POL β was able to insert and elongate an oxidized rGMP when paired with dA. We show that RNase H2 always preserves the capacity to remove a single ribonucleotide when paired to an oxidized base or to incise an oxidized ribonucleotide in a DNA duplex. In contrast, BER activity is affected by the presence of a ribonucleotide opposite an 8-oxodG. In particular, MUTYH activity on 8-oxodG:rA mispairs is fully inhibited, although its binding capacity is retained. This results in the reduction of RNase H2 incision capability of this substrate. Thus complex mispairs formed by an oxidized base and a ribonucleotide can compromise BER and RER in repeated sequences. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

In vitro excision of adeno-associated virus DNA from recombinant plasmids: Isolation of an enzyme fraction from HeLa cells that cleaves DNA at poly(G) sequences

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gottlieb, J.; Muzyczka, N.

1988-06-01

When circular recombinant plasmids containing adeno-associated virus (AAV) DNA sequences are transfected into human cells, the AAV provirus is rescued. Using these circular AAV plasmids as substrates, the authors isolated an enzyme fraction from HeLa cell nuclear extracts that excises intact AAV DNA in vitro from vector DNA and produces linear DNA products. The recognition signal for the enzyme is a polypurine-polypyrimidine sequence which is at least 9 residues long and rich in G . C base pairs. Such sequences are present in AAV recombinant plasmids as part of the first 15 base pairs of the AAV terminal repeat andmore » in some cases as the result of cloning the AAV genome by G . C tailing. The isolated enzyme fraction does not have significant endonucleolytic activity on single-stranded or double-stranded DNA. Plasmid DNA that is transfected into tissue culture cells is cleaved in vivo to produce a pattern of DNA fragments similar to that seen with purified enzyme in vitro. The activity has been called endo R for rescue, and its behavior suggests that it may have a role in recombination of cellular chromosomes.« less

Base excision repair: NMR backbone assignments of Escherichia coli formamidopyrimidine-DNA glycosylase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Buchko, Garry W.; Wallace, Susan S.; Kennedy, Michael A.

2002-03-01

Oxidative damage is emerging as one of the most important mechanisms responsible for mutagenesis, carcinogenesis, aging, and various diseases (Farr and Kogma, 1991). One of the potential targets for oxidation is cellular DNA. While exposure to exogenous agents, such as ionizing radiation and chemicals, contributes to damaging DNA, the most important oxidative agents are endogenous, such as the reactive free radicals produced during normal oxidative metabolism (Adelman et., 1988). To mitigate the potentially deleterious effects of oxidative DNA damage virtually all aerobic organisms have developed complex repair mechanisms (Petit and Sancar, 1999). One repair mechanism, base excision repair (BER), appearsmore » to be responsible for replacing most oxidative DNA damage (David and Williams, 1998). Formamidopyrimidine-DNA glycosylase (Fpg), a 269-residue metalloprotein with a molecular weight of 30.2 kDa, is a key BER enzyme in prokaryotes (Boiteaux et al., 1987). Substrates recognized and released by Fpg include 7,8-dihydro-8-oxoguanine (8-oxoG), 2,6 diamino-4-hydroxy-5-formamido pyrimidine (Fapy-G), the adenine equivalents 8-oxoA and Fapy-A, 5-hydroxycytosine, 5-hydroxyuracil, B ureidoisobutiric acid, and a-R-hydroxy-B-ureidoisobutiric acid (Freidberg et al., 1995). In vitro Fpg bind double-stranded DNA and performs three catalytic activities: (i) DNA glycosylase, (ii) AP lyase, and (iii) deoxyribophosphodiesterase.« less

A unified view of base excision repair: lesion-dependent protein complexes regulated by post-translational modification

PubMed Central

Almeida, Karen H.; Sobol, Robert W.

2007-01-01

Base excision repair (BER) proteins act upon a significantly broad spectrum of DNA lesions that result from endogenous and exogenous sources. Multiple sub-pathways of BER (short-path or long-patch) and newly designated DNA repair pathways (e.g., SSBR and NIR) that utilize BER proteins complicate any comprehensive understanding of BER and its role in genome maintenance, chemotherapeutic response, neurodegeneration, cancer or aging. Herein, we propose a unified model of BER, comprised of three functional processes: Lesion Recognition/Strand Scission, Gap Tailoring and DNA Synthesis/Ligation, each represented by one or more multiprotein complexes and coordinated via the XRCC1/DNA Ligase III and PARP1 scaffold proteins. BER therefore may be represented by a series of repair complexes that assemble at the site of the DNA lesion and mediates repair in a coordinated fashion involving protein-protein interactions that dictate subsequent steps or sub-pathway choice. Complex formation is influenced by post-translational protein modifications that arise from the cellular state or the DNA damage response, providing an increase in specificity and efficiency to the BER pathway. In this review, we have summarized the reported BER protein-protein interactions and protein post-translational modifications and discuss the impact on DNA repair capacity and complex formation. PMID:17337257

Interobserver variation in the diagnosis of fibroepithelial lesions of the breast: a multicentre audit by digital pathology.

PubMed

Dessauvagie, Benjamin F; Lee, Andrew H S; Meehan, Katie; Nijhawan, Anju; Tan, Puay Hoon; Thomas, Jeremy; Tie, Bibiana; Treanor, Darren; Umar, Seemeen; Hanby, Andrew M; Millican-Slater, Rebecca

2018-02-13

Fibroepithelial lesions (FELs) of the breast span a morphological continuum including lesions where distinction between cellular fibroadenoma (FA) and benign phyllodes tumour (PT) is difficult. The distinction is clinically important with FAs managed conservatively while equivocal lesions and PTs are managed with surgery. We sought to audit core biopsy diagnoses of equivocal FELs by digital pathology and to investigate whether digital point counting is useful in clarifying FEL diagnoses. Scanned slide images from cores and subsequent excisions of 69 equivocal FELs were examined in a multicentre audit by eight pathologists to determine the agreement and accuracy of core needle biopsy (CNB) diagnoses and by digital point counting of stromal cellularity and expansion to determine if classification could be improved. Interobserver variation was high on CNB with a unanimous diagnosis from all pathologists in only eight cases of FA, diagnoses of both FA and PT on the same CNB in 15 and a 'weak' mean kappa agreement between pathologists (k=0.36). 'Moderate' agreement was observed on CNBs among breast specialists (k=0.44) and on excision samples (k=0.49). Up to 23% of lesions confidently diagnosed as FA on CNB were PT on excision and up to 30% of lesions confidently diagnosed as PT on CNB were FA on excision. Digital point counting did not aid in the classification of FELs. Accurate and reproducible diagnosis of equivocal FELs is difficult, particularly on CNB, resulting in poor interobserver agreement and suboptimal accuracy. Given the diagnostic difficulty, and surgical implications, equivocal FELs should be reported in consultation with experienced breast pathologists as a small number of benign FAs can be selected out from equivocal lesions. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

A water-based topical Chinese traditional medicine (Zicao) for wound healing developed using 2-hydroxypropyl-β-cyclodextrin.

PubMed

Chen Chen, Ta; Yu, Song-Cu; Hsu, Chin-Mu; Tsai, Fuu-Jen; Tsai, Yuhsin

2018-05-01

Zicao is a traditional Chinese herbal medicine that has been used for the topical treatment of wounds in the form of oil-based ointment for several hundred years. To overcome the disadvantages of oil-based ointment such as irritation, discomfort, and difficulty in cleaning, this study developed a water-based topical formulation of Zicao. An ethanol extract of Zicao was included in 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) to form a water-soluble Zicao-HP-β-CD complex. The formation of the Zicao-HP-β-CD complex was determined using LC-MS, 1 H NMR, ROSEY, and solubility analysis. The bioactivity of Zicao-HP-β-CD complex in aqueous solution was evaluated using cellular uptake in vitro and experimental excision wounds in vivo. The LC-MS, 1 H NMR, ROESY, and solubility analyses results show that Zicao extract was successfully included by the HP-β-CD. The results of the cellular uptake in vitro and wound healing in vivo suggest that the effect of Zicao was enhanced following the formation of the Zicao-HP-β-CD complex. Therefore, we concluded that complexation with HP-β-CD might provide a potential method for developing an effective water-based topical solution of Zicao. Copyright © 2018 Elsevier B.V. All rights reserved.

Replication fork collapse is a major cause of the high mutation frequency at three-base lesion clusters

PubMed Central

Sedletska, Yuliya; Radicella, J. Pablo; Sage, Evelyne

2013-01-01

Unresolved repair of clustered DNA lesions can lead to the formation of deleterious double strand breaks (DSB) or to mutation induction. Here, we investigated the outcome of clusters composed of base lesions for which base excision repair enzymes have different kinetics of excision/incision. We designed multiply damaged sites (MDS) composed of a rapidly excised uracil (U) and two oxidized bases, 5-hydroxyuracil (hU) and 8-oxoguanine (oG), excised more slowly. Plasmids harboring these U-oG/hU MDS-carrying duplexes were introduced into Escherichia coli cells either wild type or deficient for DNA n-glycosylases. Induction of DSB was estimated from plasmid survival and mutagenesis determined by sequencing of surviving clones. We show that a large majority of MDS is converted to DSB, whereas almost all surviving clones are mutated at hU. We demonstrate that mutagenesis at hU is correlated with excision of the U placed on the opposite strand. We propose that excision of U by Ung initiates the loss of U-oG-carrying strand, resulting in enhanced mutagenesis at the lesion present on the opposite strand. Our results highlight the importance of the kinetics of excision by base excision repair DNA n-glycosylases in the processing and fate of MDS and provide evidence for the role of strand loss/replication fork collapse during the processing of MDS on their mutational consequences. PMID:23945941

X-ray phase-contrast tomography for high-spatial-resolution zebrafish muscle imaging

NASA Astrophysics Data System (ADS)

Vågberg, William; Larsson, Daniel H.; Li, Mei; Arner, Anders; Hertz, Hans M.

2015-11-01

Imaging of muscular structure with cellular or subcellular detail in whole-body animal models is of key importance for understanding muscular disease and assessing interventions. Classical histological methods for high-resolution imaging methods require excision, fixation and staining. Here we show that the three-dimensional muscular structure of unstained whole zebrafish can be imaged with sub-5 μm detail with X-ray phase-contrast tomography. Our method relies on a laboratory propagation-based phase-contrast system tailored for detection of low-contrast 4-6 μm subcellular myofibrils. The method is demonstrated on 20 days post fertilization zebrafish larvae and comparative histology confirms that we resolve individual myofibrils in the whole-body animal. X-ray imaging of healthy zebrafish show the expected structured muscle pattern while specimen with a dystrophin deficiency (sapje) displays an unstructured pattern, typical of Duchenne muscular dystrophy. The method opens up for whole-body imaging with sub-cellular detail also of other types of soft tissue and in different animal models.

Antecedent thermal injury worsens split-thickness skin graft quality: A clinically relevant porcine model of full-thickness burn, excision and grafting.

PubMed

Carlsson, Anders H; Rose, Lloyd F; Fletcher, John L; Wu, Jesse C; Leung, Kai P; Chan, Rodney K

2017-02-01

Current standard of care for full-thickness burn is excision followed by autologous split-thickness skin graft placement. Skin grafts are also frequently used to cover surgical wounds not amenable to linear closure. While all grafts have potential to contract, clinical observation suggests that antecedent thermal injury worsens contraction and impairs functional and aesthetic outcomes. This study evaluates the impact of antecedent full-thickness burn on split-thickness skin graft scar outcomes and the potential mediating factors. Full-thickness contact burns (100°C, 30s) were created on the backs of anesthetized female Yorkshire Pigs. After seven days, burn eschar was tangentially excised and covered with 12/1000th inch (300μm) split-thickness skin graft. For comparison, unburned wounds were created by sharp excision to fat before graft application. From 7 to 120days post-grafting, planimetric measurements, digital imaging and biopsies for histology, immunohistochemistry and gene expression were obtained. At 120days post-grafting, the Observer Scar Assessment Scale, colorimetry, contour analysis and optical graft height assessments were performed. Twenty-nine porcine wounds were analyzed. All measured metrics of clinical skin quality were significantly worse (p<0.05) in burn injured wounds. Histological analysis supported objective clinical findings with marked scar-like collagen proliferation within the dermis, increased vascular density, and prolonged and increased cellular infiltration. Observed differences in contracture also correlated with earlier and more prominent myofibroblast differentiation as demonstrated by α-SMA staining. Antecedent thermal injury worsens split-thickness skin graft quality, likely by multiple mechanisms including burn-related inflammation, microscopically inadequate excision, and dysregulation of tissue remodeling. A valid, reliable, clinically relevant model of full-thickness burn, excision and skin replacement therapy has been demonstrated. Future research to enhance quality of skin replacement therapies should be directed toward modulation of inflammation and assessments for complete excision. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

Balancing repair and tolerance of DNA damage caused by alkylating agents.

PubMed

Fu, Dragony; Calvo, Jennifer A; Samson, Leona D

2012-01-12

Alkylating agents constitute a major class of frontline chemotherapeutic drugs that inflict cytotoxic DNA damage as their main mode of action, in addition to collateral mutagenic damage. Numerous cellular pathways, including direct DNA damage reversal, base excision repair (BER) and mismatch repair (MMR), respond to alkylation damage to defend against alkylation-induced cell death or mutation. However, maintaining a proper balance of activity both within and between these pathways is crucial for a favourable response of an organism to alkylating agents. Furthermore, the response of an individual to alkylating agents can vary considerably from tissue to tissue and from person to person, pointing to genetic and epigenetic mechanisms that modulate alkylating agent toxicity.

SERIES: Genomic instability in cancer Balancing repair and tolerance of DNA damage caused by alkylating agents

PubMed Central

Fu, Dragony; Calvo, Jennifer A.; Samson, Leona D

2013-01-01

Alkylating agents comprise a major class of frontline chemotherapeutic drugs that inflict cytotoxic DNA damage as their main mode of action, in addition to collateral mutagenic damage. Numerous cellular pathways, including direct DNA damage reversal, base excision repair (BER), and mismatch repair (MMR) respond to alkylation damage to defend against alkylation-induced cell death or mutation. However, maintaining a proper balance of activity both within and between these pathways is crucial for an organism's favorable response to alkylating agents. Furthermore, an individual's response to alkylating agents can vary considerably from tissue to tissue and from person to person, pointing to genetic and epigenetic mechanisms that modulate alkylating agent toxicity. PMID:22237395

A history of the DNA repair and mutagenesis field: The discovery of base excision repair.

PubMed

Friedberg, Errol C

2016-01-01

This article reviews the early history of the discovery of an DNA repair pathway designated as base excision repair (BER), since in contrast to the enzyme-catalyzed removal of damaged bases from DNA as nucleotides [called nucleotide excision repair (NER)], BER involves the removal of damaged or inappropriate bases, such as the presence of uracil instead of thymine, from DNA as free bases. Copyright © 2015. Published by Elsevier B.V.

Phosphorylation of Nucleotide Excision Repair Factor Xeroderma Pigmentosum Group A by Ataxia Telangiectasia Mutated and Rad3-Related-Dependent Checkpoint Pathway Promotes Cell Survival in Response to UV Irradiation

PubMed Central

Wu, Xiaoming; Shell, Steven M.; Yang, Zhengguan; Zou, Yue

2006-01-01

DNA damage triggers complex cellular responses in eukaryotic cells, including initiation of DNA repair and activation of cell cycle checkpoints. In addition to inducing cell cycle arrest, checkpoint also has been suggested to modulate a variety of other cellular processes in response to DNA damage. In this study, we present evidence showing that the cellular function of xeroderma pigmentosum group A (XPA), a major nucleotide excision repair (NER) factor, could be modulated by checkpoint kinase ataxia-telangiectasia mutated and Rad3-related (ATR) in response to UV irradiation. We observed the apparent interaction and colocalization of XPA with ATR in response to UV irradiation. We showed that XPA was a substrate for in vitro phosphorylation by phosphatidylinositol-3-kinase-related kinase family kinases whereas in cells XPA was phosphorylated in an ATR-dependent manner and stimulated by UV irradiation. The Ser196 of XPA was identified as a biologically significant residue to be phosphorylated in vivo. The XPA-deficient cells complemented with XPA-S196A mutant, in which Ser196 was substituted with an alanine, displayed significantly higher UV sensitivity compared with the XPA cells complemented with wild-type XPA. Moreover, substitution of Ser196 with aspartic acid for mimicking the phosphorylation of XPA increased the cell survival to UV irradiation. Taken together, our results revealed a potential physical and functional link between NER and the ATR-dependent checkpoint pathway in human cells and suggested that the ATR checkpoint pathway could modulate the cellular activity of NER through phosphorylation of XPA at Ser196 on UV irradiation. PMID:16540648

Formation and processing of DNA damage substrates for the hNEIL enzymes.

PubMed

Fleming, Aaron M; Burrows, Cynthia J

2017-06-01

Reactive oxygen species (ROS) are harnessed by the cell for signaling at the same time as being detrimental to cellular components such as DNA. The genome and transcriptome contain instructions that can alter cellular processes when oxidized. The guanine (G) heterocycle in the nucleotide pool, DNA, or RNA is the base most prone to oxidation. The oxidatively-derived products of G consistently observed in high yields from hydroxyl radical, carbonate radical, or singlet oxygen oxidations under conditions modeling the cellular reducing environment are discussed. The major G base oxidation products are 8-oxo-7,8-dihydroguanine (OG), 5-carboxamido-5-formamido-2-iminohydantoin (2Ih), spiroiminodihydantoin (Sp), and 5-guanidinohydantoin (Gh). The yields of these products show dependency on the oxidant and the reaction context that includes nucleoside, single-stranded DNA (ssDNA), double-stranded DNA (dsDNA), and G-quadruplex DNA (G4-DNA) structures. Upon formation of these products in cells, they are recognized by the DNA glycosylases in the base excision repair (BER) pathway. This review focuses on initiation of BER by the mammalian Nei-like1-3 (NEIL1-3) glycosylases for removal of 2Ih, Sp, and Gh. The unique ability of the human NEILs to initiate removal of the hydantoins in ssDNA, bulge-DNA, bubble-DNA, dsDNA, and G4-DNA is outlined. Additionally, when Gh exists in a G4 DNA found in a gene promoter, NEIL-mediated repair is modulated by the plasticity of the G4-DNA structure provided by additional G-runs flanking the sequence. On the basis of these observations and cellular studies from the literature, the interplay between DNA oxidation and BER to alter gene expression is discussed. Copyright © 2017 Elsevier Inc. All rights reserved.

Molecular and cellular analysis of the DNA repair defect in a patient in Xeroderma pigmentosum complementation group D who has the clinical features of Xeroderma pigmentosum and Cockayne syndrome

DOE Office of Scientific and Technical Information (OSTI.GOV)

Broughton, B.C.; Thompson, A.F.; Harcourt, S.A.

1995-01-01

Xeroderma pigmentosum (XP) and Cockayne syndrome (CS) are quite distinct genetic disorders that are associated with defects in excision repair of UV-induced DNA damage. A few patients have been described previously with the clinical features of both disorders. In this paper we describe an individual in this category who has unusual cellular responses to UV light. We show that his cultured fibroblasts and lymphocytes are extremely sensitive to irradiation with UV-C, despite a level of nucleotide excision repair that is 30%-40% that of normal cells. The deficiency is assigned to the XP-D complementation group, and we have identified two causativemore » mutations in the XPD gene: a gly{yields}arg change at amino acid 675 in the allele inherited from the patient`s mother and a -1 frameshift at amino acid 669 in the allele inherited from his father. These mutations are in the C-terminal 20% of the 760-amino-acid XPD protein, in a region where we have recently identified several mutations in patients with trichothiodystrophy. 44 refs., 5 figs., 2 tabs.« less

The DNA glycosylase AlkD uses a non-base-flipping mechanism to excise bulky lesions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mullins, Elwood A.; Shi, Rongxin; Parsons, Zachary D.

Threats to genomic integrity arising from DNA damage are mitigated by DNA glycosylases, which initiate the base excision repair pathway by locating and excising aberrant nucleobases. How these enzymes find small modifications within the genome is a current area of intensive research. A hallmark of these and other DNA repair enzymes is their use of base flipping to sequester modified nucleotides from the DNA helix and into an active site pocket. Consequently, base flipping is generally regarded as an essential aspect of lesion recognition and a necessary precursor to base excision. In this paper, we present the first, to ourmore » knowledge, DNA glycosylase mechanism that does not require base flipping for either binding or catalysis. Using the DNA glycosylase AlkD from Bacillus cereus, we crystallographically monitored excision of an alkylpurine substrate as a function of time, and reconstructed the steps along the reaction coordinate through structures representing substrate, intermediate and product complexes. Instead of directly interacting with the damaged nucleobase, AlkD recognizes aberrant base pairs through interactions with the phosphoribose backbone, while the lesion remains stacked in the DNA duplex. Quantum mechanical calculations revealed that these contacts include catalytic charge–dipole and CH–π interactions that preferentially stabilize the transition state. We show in vitro and in vivo how this unique means of recognition and catalysis enables AlkD to repair large adducts formed by yatakemycin, a member of the duocarmycin family of antimicrobial natural products exploited in bacterial warfare and chemotherapeutic trials. Bulky adducts of this or any type are not excised by DNA glycosylases that use a traditional base-flipping mechanism. Finally and hence, these findings represent a new model for DNA repair and provide insights into catalysis of base excision.« less

The DNA glycosylase AlkD uses a non-base-flipping mechanism to excise bulky lesions

DOE PAGES

Mullins, Elwood A.; Shi, Rongxin; Parsons, Zachary D.; ...

2015-10-28

Threats to genomic integrity arising from DNA damage are mitigated by DNA glycosylases, which initiate the base excision repair pathway by locating and excising aberrant nucleobases. How these enzymes find small modifications within the genome is a current area of intensive research. A hallmark of these and other DNA repair enzymes is their use of base flipping to sequester modified nucleotides from the DNA helix and into an active site pocket. Consequently, base flipping is generally regarded as an essential aspect of lesion recognition and a necessary precursor to base excision. In this paper, we present the first, to ourmore » knowledge, DNA glycosylase mechanism that does not require base flipping for either binding or catalysis. Using the DNA glycosylase AlkD from Bacillus cereus, we crystallographically monitored excision of an alkylpurine substrate as a function of time, and reconstructed the steps along the reaction coordinate through structures representing substrate, intermediate and product complexes. Instead of directly interacting with the damaged nucleobase, AlkD recognizes aberrant base pairs through interactions with the phosphoribose backbone, while the lesion remains stacked in the DNA duplex. Quantum mechanical calculations revealed that these contacts include catalytic charge–dipole and CH–π interactions that preferentially stabilize the transition state. We show in vitro and in vivo how this unique means of recognition and catalysis enables AlkD to repair large adducts formed by yatakemycin, a member of the duocarmycin family of antimicrobial natural products exploited in bacterial warfare and chemotherapeutic trials. Bulky adducts of this or any type are not excised by DNA glycosylases that use a traditional base-flipping mechanism. Finally and hence, these findings represent a new model for DNA repair and provide insights into catalysis of base excision.« less

Differential sensitivities of cellular XPA and PARP-1 to arsenite inhibition and zinc rescue.

PubMed

Ding, Xiaofeng; Zhou, Xixi; Cooper, Karen L; Huestis, Juliana; Hudson, Laurie G; Liu, Ke Jian

2017-09-15

Arsenite directly binds to the zinc finger domains of the DNA repair protein poly (ADP ribose) polymerase (PARP)-1, and inhibits PARP-1 activity in the base excision repair (BER) pathway. PARP inhibition by arsenite enhances ultraviolet radiation (UVR)-induced DNA damage in keratinocytes, and the increase in DNA damage is reduced by zinc supplementation. However, little is known about the effects of arsenite and zinc on the zinc finger nucleotide excision repair (NER) protein xeroderma pigmentosum group A (XPA). In this study, we investigated the difference in response to arsenite exposure between XPA and PARP-1, and the differential effectiveness of zinc supplementation in restoring protein DNA binding and DNA damage repair. Arsenite targeted both XPA and PARP-1 in human keratinocytes, resulting in zinc loss from each protein and a pronounced decrease in XPA and PARP-1 binding to chromatin as demonstrated by Chip-on-Western assays. Zinc effectively restored DNA binding of PARP-1 and XPA to chromatin when zinc concentrations were equal to those of arsenite. In contrast, zinc was more effective in rescuing arsenite-augmented direct UVR-induced DNA damage than oxidative DNA damage. Taken together, our findings indicate that arsenite interferes with PARP-1 and XPA binding to chromatin, and that zinc supplementation fully restores DNA binding activity to both proteins in the cellular context. Interestingly, rescue of arsenite-inhibited DNA damage repair by supplemental zinc was more sensitive for DNA damage repaired by the XPA-associated NER pathway than for the PARP-1-dependent BER pathway. This study expands our understanding of arsenite's role in DNA repair inhibition and co-carcinogenesis. Copyright © 2017 Elsevier Inc. All rights reserved.

Role of DNA base excision repair in the mutability and virulence of Streptococcus mutans

PubMed Central

Gonzalez, Kaisha; Faustoferri, Roberta C.; Quivey, Robert G.

2012-01-01

Summary The oral pathogen, Streptococcus mutans, possesses inducible DNA repair defenses for protection against pH fluctuations and production of reactive oxygen metabolites such as hydrogen peroxide (H2O2), which are present in the oral cavity. DNA base excision repair (BER) has a critical role in genome maintenance by preventing the accumulation of mutations associated with environmental factors and normal products of cellular metabolism. In this study, we examined the consequences of compromising the DNA glycosylases (Fpg and MutY) and endonucleases (Smx and Smn) of the BER pathway and their relative role in adaptation and virulence. Enzymatic characterization of the BER system showed that it protects the organism against the effects of the highly mutagenic lesion, 7,8-dihydro-8-oxo-2’-deoxyguanine (8-oxo-dG). S. mutans strains lacking a functional Fpg, MutY, or Smn showed elevated spontaneous mutation frequencies; and, these mutator phenotypes correlated with the ability of the strains to survive killing by acid and oxidative agents. In addition, in the G. mellonella virulence model, strains of S. mutans deficient in Fpg, MutY and Smn showed increased virulence as compared to the parent strain. Our results suggest that, for S. mutans, mutator phenotypes, due to loss of BER enzymes, may confer an advantage to virulence of the organism. PMID:22651851

Epistatic role of base excision repair and mismatch repair pathways in mediating cisplatin cytotoxicity

PubMed Central

Kothandapani, Anbarasi; Sawant, Akshada; Dangeti, Venkata Srinivas Mohan Nimai; Sobol, Robert W.; Patrick, Steve M.

2013-01-01

Base excision repair (BER) and mismatch repair (MMR) pathways play an important role in modulating cis-Diamminedichloroplatinum (II) (cisplatin) cytotoxicity. In this article, we identified a novel mechanistic role of both BER and MMR pathways in mediating cellular responses to cisplatin treatment. Cells defective in BER or MMR display a cisplatin-resistant phenotype. Targeting both BER and MMR pathways resulted in no additional resistance to cisplatin, suggesting that BER and MMR play epistatic roles in mediating cisplatin cytotoxicity. Using a DNA Polymerase β (Polβ) variant deficient in polymerase activity (D256A), we demonstrate that MMR acts downstream of BER and is dependent on the polymerase activity of Polβ in mediating cisplatin cytotoxicity. MSH2 preferentially binds a cisplatin interstrand cross-link (ICL) DNA substrate containing a mismatch compared with a cisplatin ICL substrate without a mismatch, suggesting a novel mutagenic role of Polβ in activating MMR in response to cisplatin. Collectively, these results provide the first mechanistic model for BER and MMR functioning within the same pathway to mediate cisplatin sensitivity via non-productive ICL processing. In this model, MMR participation in non-productive cisplatin ICL processing is downstream of BER processing and dependent on Polβ misincorporation at cisplatin ICL sites, which results in persistent cisplatin ICLs and sensitivity to cisplatin. PMID:23761438

ALKBH7 drives a tissue and sex-specific necrotic cell death response following alkylation-induced damage

PubMed Central

Jordan, Jennifer J; Chhim, Sophea; Margulies, Carrie M; Allocca, Mariacarmela; Bronson, Roderick T; Klungland, Arne; Samson, Leona D; Fu, Dragony

2017-01-01

Regulated necrosis has emerged as a major cell death mechanism in response to different forms of physiological and pharmacological stress. The AlkB homolog 7 (ALKBH7) protein is required for regulated cellular necrosis in response to chemotherapeutic alkylating agents but its role within a whole organism is unknown. Here, we show that ALKBH7 modulates alkylation-induced cellular death through a tissue and sex-specific mechanism. At the whole-animal level, we find that ALKBH7 deficiency confers increased resistance to MMS-induced toxicity in male but not female mice. Moreover, ALKBH7-deficient mice exhibit protection against alkylation-mediated cytotoxicity in retinal photoreceptor and cerebellar granule cells, two cell types that undergo necrotic death through the initiation of the base excision repair pathway and hyperactivation of the PARP1/ARTD1 enzyme. Notably, the protection against alkylation-induced cerebellar degeneration is specific to ALKBH7-deficient male but not female mice. Our results uncover an in vivo role for ALKBH7 in mediating a sexually dimorphic tissue response to alkylation damage that could influence individual responses to chemotherapies based upon alkylating agents. PMID:28726787

Regulation of DNA repair in serum-stimulated xeroderma pigmentosum cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gupta, P.K.; Sirover, M.A.

1984-10-01

The regulation of DNA repair during serum stimulation of quiescent cells was examined in normal human cells, in fibroblasts from three xeroderma pigmentosum complementation groups (A, C, and D), in xeroderma pigmentosum variant cells, and in ataxia telangiectasia cells. The regulation of nucleotide excision repair was examined by exposing cells to ultraviolet irradiation at discrete intervals after cell stimulation. Similarly, base excision repair was quantitated after exposure to methylmethane sulfonate. WI-38 normal human diploid fibroblasts, xeroderma pigmentosum variant cells, as well as ataxia telangiectasia cells enhanced their capacity for both nucleotide excision repair and for base excision repair prior tomore » their enhancement of DNA synthesis. Further, in each cell strain, the base excision repair enzyme uracil DNA glycosylase was increased prior to the induction of DNA polymerase using the identical cells to quantitate each activity. In contrast, each of the three xeroderma complementation groups that were examined failed to increase their capacity for nucleotide excision repair above basal levels at any interval examined. This result was observed using either unscheduled DNA synthesis in the presence of 10 mM hydroxyurea or using repair replication in the absence of hydroxyurea to quantitate DNA repair. However, each of the three complementation groups normally regulated the enhancement of base excision repair after methylmethane sulfonate exposure and each induced the uracil DNA glycosylase prior to DNA synthesis. 62 references, 3 figures, 2 tables.« less

Selective base excision repair of DNA damage by the non-base-flipping DNA glycosylase AlkC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shi, Rongxin; Mullins, Elwood A.; Shen, Xing‐Xing

DNA glycosylases preserve genome integrity and define the specificity of the base excision repair pathway for discreet, detrimental modifications, and thus, the mechanisms by which glycosylases locate DNA damage are of particular interest. Bacterial AlkC and AlkD are specific for cationic alkylated nucleobases and have a distinctive HEAT-like repeat (HLR) fold. AlkD uses a unique non-base-flipping mechanism that enables excision of bulky lesions more commonly associated with nucleotide excision repair. In contrast, AlkC has a much narrower specificity for small lesions, principally N3-methyladenine (3mA). Here, we describe how AlkC selects for and excises 3mA using a non-base-flipping strategy distinct frommore » that of AlkD. A crystal structure resembling a catalytic intermediate complex shows how AlkC uses unique HLR and immunoglobulin-like domains to induce a sharp kink in the DNA, exposing the damaged nucleobase to active site residues that project into the DNA. This active site can accommodate and excise N3-methylcytosine (3mC) and N1-methyladenine (1mA), which are also repaired by AlkB-catalyzed oxidative demethylation, providing a potential alternative mechanism for repair of these lesions in bacteria.« less

Tri-modal confocal mosaics detect residual invasive squamous cell carcinoma in Mohs surgical excisions

NASA Astrophysics Data System (ADS)

Gareau, Dan; Bar, Anna; Snaveley, Nicholas; Lee, Ken; Chen, Nathaniel; Swanson, Neil; Simpson, Eric; Jacques, Steve

2012-06-01

For rapid, intra-operative pathological margin assessment to guide staged cancer excisions, multimodal confocal mosaic scan image wide surgical margins (approximately 1 cm) with sub-cellular resolution and mimic the appearance of conventional hematoxylin and eosin histopathology (H&E). The goal of this work is to combine three confocal imaging modes: acridine orange fluorescence (AO) for labeling nuclei, eosin fluorescence (Eo) for labeling cytoplasm, and endogenous reflectance (R) for marking collagen and keratin. Absorption contrast is achieved by alternating the excitation wavelength: 488 nm (AO fluorescence) and 532 nm (Eo fluorescence). Superposition and false-coloring of these modes mimics H&E, enabling detection of cutaneous squamous cell carcinomas (SCC). The sum of mosaic Eo+R is false-colored pink to mimic the appearance of eosin, while the AO mosaic is false-colored purple to mimic the appearance of hematoxylin in H&E. In this study, mosaics of 10 Mohs surgical excisions containing invasive SCC, and five containing only normal tissue were subdivided for digital presentation equivalent to 4× histology. Of the total 50 SCC and 25 normal sub-mosaics presented, two reviewers made two and three type-2 errors (false positives), respectively. Limitations to precisely mimic H&E included occasional elastin staining by AO. These results suggest that confocal mosaics may effectively guide staged SCC excisions in skin and other tissues.

Analysis of sequence variability in the macronuclear DNA of Paramecium tetraurelia: A somatic view of the germline

PubMed Central

Duret, Laurent; Cohen, Jean; Jubin, Claire; Dessen, Philippe; Goût, Jean-François; Mousset, Sylvain; Aury, Jean-Marc; Jaillon, Olivier; Noël, Benjamin; Arnaiz, Olivier; Bétermier, Mireille; Wincker, Patrick; Meyer, Eric; Sperling, Linda

2008-01-01

Ciliates are the only unicellular eukaryotes known to separate germinal and somatic functions. Diploid but silent micronuclei transmit the genetic information to the next sexual generation. Polyploid macronuclei express the genetic information from a streamlined version of the genome but are replaced at each sexual generation. The macronuclear genome of Paramecium tetraurelia was recently sequenced by a shotgun approach, providing access to the gene repertoire. The 72-Mb assembly represents a consensus sequence for the somatic DNA, which is produced after sexual events by reproducible rearrangements of the zygotic genome involving elimination of repeated sequences, precise excision of unique-copy internal eliminated sequences (IES), and amplification of the cellular genes to high copy number. We report use of the shotgun sequencing data (>106 reads representing 13× coverage of a completely homozygous clone) to evaluate variability in the somatic DNA produced by these developmental genome rearrangements. Although DNA amplification appears uniform, both of the DNA elimination processes produce sequence heterogeneity. The variability that arises from IES excision allowed identification of hundreds of putative new IESs, compared to 42 that were previously known, and revealed cases of erroneous excision of segments of coding sequences. We demonstrate that IESs in coding regions are under selective pressure to introduce premature termination of translation in case of excision failure. PMID:18256234

Tri-modal confocal mosaics detect residual invasive squamous cell carcinoma in Mohs surgical excisions

PubMed Central

Bar, Anna; Snaveley, Nicholas; Lee, Ken; Chen, Nathaniel; Swanson, Neil; Simpson, Eric; Jacques, Steve

2012-01-01

Abstract. For rapid, intra-operative pathological margin assessment to guide staged cancer excisions, multimodal confocal mosaic scan image wide surgical margins (approximately 1 cm) with sub-cellular resolution and mimic the appearance of conventional hematoxylin and eosin histopathology (H&E). The goal of this work is to combine three confocal imaging modes: acridine orange fluorescence (AO) for labeling nuclei, eosin fluorescence (Eo) for labeling cytoplasm, and endogenous reflectance (R) for marking collagen and keratin. Absorption contrast is achieved by alternating the excitation wavelength: 488 nm (AO fluorescence) and 532 nm (Eo fluorescence). Superposition and false-coloring of these modes mimics H&E, enabling detection of cutaneous squamous cell carcinomas (SCC). The sum of mosaic Eo+R is false-colored pink to mimic the appearance of eosin, while the AO mosaic is false-colored purple to mimic the appearance of hematoxylin in H&E. In this study, mosaics of 10 Mohs surgical excisions containing invasive SCC, and five containing only normal tissue were subdivided for digital presentation equivalent to 4× histology. Of the total 50 SCC and 25 normal sub-mosaics presented, two reviewers made two and three type-2 errors (false positives), respectively. Limitations to precisely mimic H&E included occasional elastin staining by AO. These results suggest that confocal mosaics may effectively guide staged SCC excisions in skin and other tissues. PMID:22734774

Amplification of unscheduled DNA synthesis signal enables fluorescence-based single cell quantification of transcription-coupled nucleotide excision repair

PubMed Central

Wienholz, Franziska; Vermeulen, Wim

2017-01-01

Abstract Nucleotide excision repair (NER) comprises two damage recognition pathways: global genome NER (GG-NER) and transcription-coupled NER (TC-NER), which remove a wide variety of helix-distorting lesions including UV-induced damage. During NER, a short stretch of single-stranded DNA containing damage is excised and the resulting gap is filled by DNA synthesis in a process called unscheduled DNA synthesis (UDS). UDS is measured by quantifying the incorporation of nucleotide analogues into repair patches to provide a measure of NER activity. However, this assay is unable to quantitatively determine TC-NER activity due to the low contribution of TC-NER to the overall NER activity. Therefore, we developed a user-friendly, fluorescence-based single-cell assay to measure TC-NER activity. We combined the UDS assay with tyramide-based signal amplification to greatly increase the UDS signal, thereby allowing UDS to be quantified at low UV doses, as well as DNA-repair synthesis of other excision-based repair mechanisms such as base excision repair and mismatch repair. Importantly, we demonstrated that the amplified UDS is sufficiently sensitive to quantify TC-NER-derived repair synthesis in GG-NER-deficient cells. This assay is important as a diagnostic tool for NER-related disorders and as a research tool for obtaining new insights into the mechanism and regulation of excision repair. PMID:28088761

Impact of in vivo reflectance confocal microscopy on the number needed to treat melanoma in doubtful lesions

PubMed Central

Alarcon, I.; Carrera, C.; Palou, J.; Alos, L.; Malvehy, J.; Puig, S.

2013-01-01

Background The number needed to treat ratio is an effective method for measuring accuracy in melanoma detection. Dermoscopy reduces the number of false positives and subsequently unnecessary excisions. In vivo confocal microscopy is a non-invasive technique which allows the examination of the skin with cellular resolution. Objectives To assess the impact of RCM analysis on the number of equivocal lesions, assumed to be melanocytic, excised for every melanoma. Methods Consecutive patients (n=343) presenting with doubtful lesions, were considered for enrolment. The lesions were analysed by dermoscopy and RCM and histopathological assessment was considered the reference standard. The main outcome was the number needed to treat, calculated as the proportion of equivocal lesions, excised for every melanoma. Results Dermoscopy alone obtained a hypothetical NNT of 3.73, the combination of dermoscopy and RCM identified 264 equivocal lesions that qualified for excision, 92 of which were confirmed to be a melanoma; resulting in a NNT of 2.87; whereas the analysis of RCM images classified as melanoma 103 lesions with a consequent NNT of 1.12; the difference in the reduction of this ratio was statistically significant (p< 0.0001) between the three groups. There was no significant improvement in sensitivity when comparing the combination of dermoscopy and RCM and RCM alone (94.56% vs. 97.82%; p = 0.043). However, the differences between specificities were statistically significant (p <0.000001), favouring RCM alone. Conclusion The addition of RCM analysis to dermoscopy reduces unnecessary excisions with a high diagnostic accuracy and could be a means for reducing the economic impact associated with the management of skin cancer. PMID:24124911

Day and night variations in the repair of ionizing-radiation-induced DNA damage in mouse splenocytes.

PubMed

Palombo, Philipp; Moreno-Villanueva, Maria; Mangerich, Aswin

2015-04-01

In mammals, biological rhythms synchronize physiological and behavioral processes to the 24-h light-dark (LD) cycle. At the molecular level, self-sustaining processes, such as oscillations of transcription-translation feedback loops, control the circadian clock, which in turn regulates a wide variety of cellular processes, including gene expression and cell cycle progression. Furthermore, previous studies reported circadian oscillations in the repair capacity of DNA lesions specifically repaired by nucleotide excision repair (NER). However, it is so far only poorly understood if DNA repair pathways other than NER are under circadian control, in particular base excision and DNA strand break repair. In the present study, we analyzed potential day and night variations in the repair of DNA lesions induced by ionizing radiation (i.e., mainly oxidative damage and DNA strand breaks) in living mouse splenocytes using a modified protocol of the automated FADU assay. Our results reveal that splenocytes isolated from mice during the light phase (ZT06) displayed higher DNA repair activity than those of the dark phase (ZT18). As analyzed by highly sensitive and accurate qPCR arrays, these alterations were accompanied by significant differences in expression profiles of genes involved in the circadian clock and DNA repair. Notably, the majority of the DNA repair genes were expressed at higher levels during the light phase (ZT06). This included genes of all major DNA repair pathways with the strongest differences observed for genes of base excision and DNA double strand break repair. In conclusion, here we provide novel evidence that mouse splenocytes exhibit significant differences in the repair of IR-induced DNA damage during the LD cycle, both on a functional and on a gene expression level. It will be interesting to test if these findings could be exploited for therapeutic purposes, e.g. time-of-the-day-specific application of DNA-damaging treatments used against blood malignancies. Copyright © 2015 Elsevier B.V. All rights reserved.

Regulation and disregulation of mammalian nucleotide excision repair: A pathway to nongermline breast carcinogenesis

DOE PAGES

Latimer, Jean J.; Majekwana, Vongai J.; Pabon-Padin, Yashira R.; ...

2014-12-19

Nucleotide excision repair (NER) is important as a modulator of disease, especially in constitutive deficiencies, such as the cancer predisposition syndrome Xeroderma pigmentosum. We have found profound variation of NER capacity among normal individuals, between cell-types and during carcinogenesis. NER is a repair system for many types of DNA damage, and therefore many types of genotoxic carcinogenic exposures, including ultraviolet light, products of organic combustion, metals, oxidative stress, etc. Since NER is intimately related to cellular metabolism, requiring components of both the DNA replicative and transcription machinery, it has a narrow range of functional viability. Thus, genes in the NERmore » pathway are expressed at the low levels manifested by, for example, nuclear transcription factors. Since NER activity and gene expression vary by cell-type, it is inherently epigenetically regulated. Furthermore, this epigenetic regulation is disregulated during sporadic breast carcinogenesis. Loss of NER is one basis of genomic instability, a required element in cellular transformation, and one that potentially modulates response to therapy. In this article, we demonstrate differences in NER capacity in eight adult mouse tissues, and place this result into the context of our previous work on mouse extraembryonic tissues, normal human tissues and sporadic early stage human breast cancer.« less

Updated evidence-based clinical practice guidelines for the diagnosis and management of melanoma: definitive excision margins for primary cutaneous melanoma.

PubMed

Sladden, Michael J; Nieweg, Omgo E; Howle, Julie; Coventry, Brendon J; Thompson, John F

2018-02-19

Definitive management of primary cutaneous melanoma consists of surgical excision of the melanoma with the aim of curing the patient. The melanoma is widely excised together with a safety margin of surrounding skin and subcutaneous tissue, after the diagnosis and Breslow thickness have been established by histological assessment of the initial excision biopsy specimen. Sentinel lymph node biopsy should be discussed for melanomas ≥ 1 mm thickness (≥ 0.8 mm if other high risk features) in which case lymphoscintigraphy must be performed before wider excision of the primary melanoma site. The 2008 evidence-based clinical practice guidelines for the management of melanoma (http://www.cancer.org.au/content/pdf/HealthProfessionals/ClinicalGuidelines/ClinicalPracticeGuidelines-ManagementofMelanoma.pdf) are currently being revised and updated in a staged process by a multidisciplinary working party established by Cancer Council Australia. The guidelines for definitive excision margins for primary melanomas have been revised as part of this process. Main recommendations: The recommendations for definitive wide local excision of primary cutaneous melanoma are: melanoma in situ: 5-10 mm margins invasive melanoma (pT1) ≤ 1.0 mm thick: 1 cm margins invasive melanoma (pT2) 1.01-2.00 mm thick: 1-2 cm margins invasive melanoma (pT3) 2.01-4.00 mm thick: 1-2 cm margins invasive melanoma (pT4) > 4.0 mm thick: 2 cm margins Changes in management as a result of the guideline: Based on currently available evidence, excision margins for invasive melanoma have been left unchanged compared with the 2008 guidelines. However, melanoma in situ should be excised with 5-10 mm margins, with the aim of achieving complete histological clearance. Minimum clearances from all margins should be assessed and stated. Consideration should be given to further excision if necessary; positive or close histological margins are unacceptable.

Angiofibroma of the vulva.

PubMed

Ahmadnia, Hassan; Kamalati, Ali; Dolati, Mahmood; Akhavan Rezayat, Alireza; Katebi, Mehrdad

2014-01-01

Cellular angiofibroma is a benign and rare tumor. It usually arises in middle-aged women and involves the vulva. Complete local excision of the tumor is the best cure, and, usually, there is no recurrence after surgery. We describe a 20-year-old woman with a painless, growing vulvar mass who presented about 3 years ago. Her past medical history was negative for oral contraceptives, tobacco, and alcohol, and there were no similar lesions in her family history. A physical examination revealed two masses on the right and the left labia majora and similar lesions on the left axilla and both breasts. An uncomplicated simple resection of the vulvar masses was done in the operating room. There was no evidence of recurrence 12 months after surgery. Histopathologic examination revealed that the findings were consistent with the diagnosis of the cellular angiofibroma. Based on our knowledge, this patient is the youngest case of vulvar angiofibroma. The lesions were large and symmetrical (on both labia majora), although they differed in size. Extravulvar (breast and axilla) lesions were also noteworthy in this patient.

Nucleotide Excision Repair and Transcriptional Regulation: TFIIH and Beyond.

PubMed

Compe, Emmanuel; Egly, Jean-Marc

2016-06-02

Transcription factor IIH (TFIIH) is a multiprotein complex involved in both transcription and DNA repair, revealing a striking functional link between these two processes. Some of its subunits also belong to complexes involved in other cellular processes, such as chromosome segregation and cell cycle regulation, emphasizing the multitasking capabilities of this factor. This review aims to depict the structure of TFIIH and to dissect the roles of its subunits in different cellular mechanisms. Our understanding of the biochemistry of TFIIH has greatly benefited from studies focused on diseases related to TFIIH mutations. We address the etiology of these disorders and underline the fact that TFIIH can be considered a promising target for therapeutic strategies.

Delineating the requirements for spontaneous DNA damage resistance pathways in genome maintenance and viability in Saccharomyces cerevisiae.

PubMed

Morey, Natalie J; Doetsch, Paul W; Jinks-Robertson, Sue

2003-06-01

Cellular metabolic processes constantly generate reactive species that damage DNA. To counteract this relentless assault, cells have developed multiple pathways to resist damage. The base excision repair (BER) and nucleotide excision repair (NER) pathways remove damage whereas the recombination (REC) and postreplication repair (PRR) pathways bypass the damage, allowing deferred removal. Genetic studies in yeast indicate that these pathways can process a common spontaneous lesion(s), with mutational inactivation of any pathway increasing the burden on the remaining pathways. In this study, we examine the consequences of simultaneously compromising three or more of these pathways. Although the presence of a functional BER pathway alone is able to support haploid growth, retention of the NER, REC, or PRR pathway alone is not, indicating that BER is the key damage resistance pathway in yeast and may be responsible for the removal of the majority of either spontaneous DNA damage or specifically those lesions that are potentially lethal. In the diploid state, functional BER, NER, or REC alone can support growth, while PRR alone is insufficient for growth. In diploids, the presence of PRR alone may confer a lethal mutation load or, alternatively, PRR alone may be insufficient to deal with potentially lethal, replication-blocking lesions.

Human cells contain a factor that facilitates the DNA glycosylase-mediated excision of oxidized bases from occluded sites in nucleosomes.

PubMed

Maher, R L; Marsden, C G; Averill, A M; Wallace, S S; Sweasy, J B; Pederson, D S

2017-09-01

Reactive oxygen species generate some 20,000 base lesions per human cell per day. The vast majority of these potentially mutagenic or cytotoxic lesions are subject to base excision repair (BER). Although chromatin remodelers have been shown to enhance the excision of oxidized bases from nucleosomes in vitro, it is not clear that they are recruited to and act at sites of BER in vivo. To test the hypothesis that cells possess factors that enhance BER in chromatin, we assessed the capacity of nuclear extracts from human cells to excise thymine glycol (Tg) lesions from exogenously added, model nucleosomes. The DNA glycosylase NTHL1 in these extracts was able to excise Tg from both naked DNA and sites in nucleosomes that earlier studies had shown to be sterically accessible. However, the same extracts were able to excise lesions from sterically-occluded sites in nucleosomes only after the addition of Mg 2+ /ATP. Gel mobility shift assays indicated that nucleosomes remain largely intact following the Mg 2+ /ATP -dependent excision reaction. Size exclusion chromatography indicated that the NTHL1-stimulating activity has a relatively low molecular weight, close to that of NTHL1 and other BER glycosylases; column fractions that contained the very large chromatin remodeling complexes did not exhibit this same stimulatory activity. These results indicate that cells possess a factor(s) that promotes the initiation of BER in chromatin, but differs from most known chromatin remodeling complexes. Copyright © 2017 Elsevier B.V. All rights reserved.

Base excision repair imbalance in colorectal cancer has prognostic value and modulates response to chemotherapy

PubMed Central

Leguisamo, Natalia M.; Gloria, Helena C.; Kalil, Antonio N.; Martins, Talita V.; Azambuja, Daniel B.

2017-01-01

Colorectal cancer (CRC) is prevalent worldwide, and treatment often involves surgery and genotoxic chemotherapy. DNA repair mechanisms, such as base excision repair (BER) and mismatch repair (MMR), may not only influence tumour characteristics and prognosis but also dictate chemotherapy response. Defective MMR contributes to chemoresistance in colorectal cancer. Moreover, BER affects cellular survival by repairing genotoxic base damage in a process that itself can disrupt metabolism. In this study, we characterized BER and MMR gene expression in colorectal tumours and the association between this repair profile with patients’ clinical and pathological features. In addition, we exploited the possible mechanisms underlying the association between altered DNA repair, metabolism and response to chemotherapy. Seventy pairs of sporadic colorectal tumour samples and adjacent non-tumour mucosal specimens were assessed for BER and MMR gene and protein expression and their association with pathological and clinical features. MMR-deficient colon cancer cells (HCT116) transiently overexpressing MPG or XRCC1 were treated with 5-FU or TMZ and evaluated for viability and metabolic intermediate levels. Increase in BER gene and protein expression is associated with more aggressive tumour features and poor pathological outcomes in CRC. However, tumours with reduced MMR gene expression also displayed low MPG, OGG1 and PARP1 expression. Imbalancing BER by overexpression of MPG, but not XRCC1, sensitises MMR-deficient colon cancer cells to 5-FU and TMZ and leads to ATP depletion and lactate accumulation. MPG overexpression alters DNA repair and metabolism and is a potential strategy to overcome 5-FU chemotherapeutic resistance in MMR-deficient CRC. PMID:28903334

DNA Repair Deficiency in Neurodegeneration

PubMed Central

Jeppesen, Dennis Kjølhede; Bohr, Vilhelm A.; Stevnsner, Tinna

2011-01-01

Deficiency in repair of nuclear and mitochondrial DNA damage has been linked to several neurodegenerative disorders. Many recent experimental results indicate that the post-mitotic neurons are particularly prone to accumulation of unrepaired DNA lesions potentially leading to progressive neurodegeneration. Nucleotide excision repair is the cellular pathway responsible for removing helix-distorting DNA damage and deficiency in such repair is found in a number of diseases with neurodegenerative phenotypes, including Xeroderma Pigmentosum and Cockayne syndrome. The main pathway for repairing oxidative base lesions is base excision repair, and such repair is crucial for neurons given their high rates of oxygen metabolism. Mismatch repair corrects base mispairs generated during replication and evidence indicates that oxidative DNA damage can cause this pathway to expand trinucleotide repeats, thereby causing Huntington’s disease. Single-strand breaks are common DNA lesions and are associated with the neurodegenerative diseases, ataxia-oculomotor apraxia-1 and spinocerebellar ataxia with axonal neuropathy-1. DNA double-strand breaks are toxic lesions and two main pathways exist for their repair: homologous recombination and non-homologous end-joining. Ataxia telangiectasia and related disorders with defects in these pathways illustrate that such defects can lead to early childhood neurodegeneration. Aging is a risk factor for neurodegeneration and accumulation of oxidative mitochondrial DNA damage may be linked with the age-associated neurodegenerative disorders Alzheimer’s disease, Parkinson’s disease and amyotrophic lateral sclerosis. Mutation in the WRN protein leads to the premature aging disease Werner syndrome, a disorder that features neurodegeneration. In this article we review the evidence linking deficiencies in the DNA repair pathways with neurodegeneration. PMID:21550379

Extra-dimensional Demons: a method for incorporating missing tissue in deformable image registration.

PubMed

Nithiananthan, Sajendra; Schafer, Sebastian; Mirota, Daniel J; Stayman, J Webster; Zbijewski, Wojciech; Reh, Douglas D; Gallia, Gary L; Siewerdsen, Jeffrey H

2012-09-01

A deformable registration method capable of accounting for missing tissue (e.g., excision) is reported for application in cone-beam CT (CBCT)-guided surgical procedures. Excisions are identified by a segmentation step performed simultaneous to the registration process. Tissue excision is explicitly modeled by increasing the dimensionality of the deformation field to allow motion beyond the dimensionality of the image. The accuracy of the model is tested in phantom, simulations, and cadaver models. A variant of the Demons deformable registration algorithm is modified to include excision segmentation and modeling. Segmentation is performed iteratively during the registration process, with initial implementation using a threshold-based approach to identify voxels corresponding to "tissue" in the moving image and "air" in the fixed image. With each iteration of the Demons process, every voxel is assigned a probability of excision. Excisions are modeled explicitly during registration by increasing the dimensionality of the deformation field so that both deformations and excisions can be accounted for by in- and out-of-volume deformations, respectively. The out-of-volume (i.e., fourth) component of the deformation field at each voxel carries a magnitude proportional to the excision probability computed in the excision segmentation step. The registration accuracy of the proposed "extra-dimensional" Demons (XDD) and conventional Demons methods was tested in the presence of missing tissue in phantom models, simulations investigating the effect of excision size on registration accuracy, and cadaver studies emulating realistic deformations and tissue excisions imparted in CBCT-guided endoscopic skull base surgery. Phantom experiments showed the normalized mutual information (NMI) in regions local to the excision to improve from 1.10 for the conventional Demons approach to 1.16 for XDD, and qualitative examination of the resulting images revealed major differences: the conventional Demons approach imparted unrealistic distortions in areas around tissue excision, whereas XDD provided accurate "ejection" of voxels within the excision site and maintained the registration accuracy throughout the rest of the image. Registration accuracy in areas far from the excision site (e.g., > ∼5 mm) was identical for the two approaches. Quantitation of the effect was consistent in analysis of NMI, normalized cross-correlation (NCC), target registration error (TRE), and accuracy of voxels ejected from the volume (true-positive and false-positive analysis). The registration accuracy for conventional Demons was found to degrade steeply as a function of excision size, whereas XDD was robust in this regard. Cadaver studies involving realistic excision of the clivus, vidian canal, and ethmoid sinuses demonstrated similar results, with unrealistic distortion of anatomy imparted by conventional Demons and accurate ejection and deformation for XDD. Adaptation of the Demons deformable registration process to include segmentation (i.e., identification of excised tissue) and an extra dimension in the deformation field provided a means to accurately accommodate missing tissue between image acquisitions. The extra-dimensional approach yielded accurate "ejection" of voxels local to the excision site while preserving the registration accuracy (typically subvoxel) of the conventional Demons approach throughout the rest of the image. The ability to accommodate missing tissue volumes is important to application of CBCT for surgical guidance (e.g., skull base drillout) and may have application in other areas of CBCT guidance.

Extra-dimensional Demons: A method for incorporating missing tissue in deformable image registration

PubMed Central

Nithiananthan, Sajendra; Schafer, Sebastian; Mirota, Daniel J.; Stayman, J. Webster; Zbijewski, Wojciech; Reh, Douglas D.; Gallia, Gary L.; Siewerdsen, Jeffrey H.

2012-01-01

Purpose: A deformable registration method capable of accounting for missing tissue (e.g., excision) is reported for application in cone-beam CT (CBCT)-guided surgical procedures. Excisions are identified by a segmentation step performed simultaneous to the registration process. Tissue excision is explicitly modeled by increasing the dimensionality of the deformation field to allow motion beyond the dimensionality of the image. The accuracy of the model is tested in phantom, simulations, and cadaver models. Methods: A variant of the Demons deformable registration algorithm is modified to include excision segmentation and modeling. Segmentation is performed iteratively during the registration process, with initial implementation using a threshold-based approach to identify voxels corresponding to “tissue” in the moving image and “air” in the fixed image. With each iteration of the Demons process, every voxel is assigned a probability of excision. Excisions are modeled explicitly during registration by increasing the dimensionality of the deformation field so that both deformations and excisions can be accounted for by in- and out-of-volume deformations, respectively. The out-of-volume (i.e., fourth) component of the deformation field at each voxel carries a magnitude proportional to the excision probability computed in the excision segmentation step. The registration accuracy of the proposed “extra-dimensional” Demons (XDD) and conventional Demons methods was tested in the presence of missing tissue in phantom models, simulations investigating the effect of excision size on registration accuracy, and cadaver studies emulating realistic deformations and tissue excisions imparted in CBCT-guided endoscopic skull base surgery. Results: Phantom experiments showed the normalized mutual information (NMI) in regions local to the excision to improve from 1.10 for the conventional Demons approach to 1.16 for XDD, and qualitative examination of the resulting images revealed major differences: the conventional Demons approach imparted unrealistic distortions in areas around tissue excision, whereas XDD provided accurate “ejection” of voxels within the excision site and maintained the registration accuracy throughout the rest of the image. Registration accuracy in areas far from the excision site (e.g., > ∼5 mm) was identical for the two approaches. Quantitation of the effect was consistent in analysis of NMI, normalized cross-correlation (NCC), target registration error (TRE), and accuracy of voxels ejected from the volume (true-positive and false-positive analysis). The registration accuracy for conventional Demons was found to degrade steeply as a function of excision size, whereas XDD was robust in this regard. Cadaver studies involving realistic excision of the clivus, vidian canal, and ethmoid sinuses demonstrated similar results, with unrealistic distortion of anatomy imparted by conventional Demons and accurate ejection and deformation for XDD. Conclusions: Adaptation of the Demons deformable registration process to include segmentation (i.e., identification of excised tissue) and an extra dimension in the deformation field provided a means to accurately accommodate missing tissue between image acquisitions. The extra-dimensional approach yielded accurate “ejection” of voxels local to the excision site while preserving the registration accuracy (typically subvoxel) of the conventional Demons approach throughout the rest of the image. The ability to accommodate missing tissue volumes is important to application of CBCT for surgical guidance (e.g., skull base drillout) and may have application in other areas of CBCT guidance. PMID:22957637

A novel function of adenomatous polyposis coli (APC) in regulating DNA repair

PubMed Central

Jaiswal, Aruna S.; Narayan, Satya

2008-01-01

Prevailing literature suggests diversified cellular functions for the adenomatous polyposis coli (APC) gene. Among them a recently discovered unique role of APC is in DNA repair. The APC gene can modulate the base excision repair (BER) pathway through an interaction with DNA polymerase β (Pol-β) and flap endonuclease 1 (Fen-1). Taken together with the transcriptional activation of APC gene by alkylating agents and modulation of BER activity, APC may play an important role in carcinogenesis and chemotherapy by determining whether cells with DNA damage survive or undergo apoptosis. In this review, we summarize the evidence supporting this novel concept and suggest that these results will have implications for the development of more effective strategies for chemoprevention, prognosis, and chemotherapy of certain types of tumors. PMID:18662849

Evaluation of breast tissue with confocal strip-mosaicking microscopy: a test approach emulating pathology-like examination

PubMed Central

Abeytunge, Sanjee; Larson, Bjorg; Peterson, Gary; Morrow, Monica; Rajadhyaksha, Milind

2017-01-01

Abstract. Confocal microscopy is an emerging technology for rapid imaging of freshly excised tissue without the need for frozen- or fixed-section processing. Initial studies have described imaging of breast tissue using fluorescence confocal microscopy with small regions of interest, typically 750×750  μm2. We present exploration with a microscope, termed confocal strip-mosaicking microscope (CSM microscope), which images an area of 2×2  cm2 of tissue with cellular-level resolution in 10 min of excision. Using the CSM microscope, we imaged 34 fresh, human, large breast tissue specimens from 18 patients, blindly analyzed by a board-certified pathologist and subsequently correlated with the corresponding standard fixed histopathology. Invasive tumors and benign tissue were clearly identified in CSM strip-mosaic images. Thirty specimens were concordant for image-to-histopathology correlation while four were discordant. PMID:28327961

Base Excision Repair Facilitates a Functional Relationship Between Guanine Oxidation and Histone Demethylation

PubMed Central

Li, Jianfeng; Braganza, Andrea

2013-01-01

Abstract Significance: Appropriately controlled epigenetic regulation is critical for the normal development and health of an organism. Misregulation of epigenetic control via deoxyribonucleic acid (DNA) methylation or histone methylation has been associated with cancer and chromosomal instability syndromes. Recent Advances: The main function of the proteins in the base excision repair (BER) pathway is to repair DNA single-strand breaks and deamination, oxidation, and alkylation-induced DNA base damage that may result from chemotherapy, environmental exposure, or byproducts of cellular metabolism. Recent studies have suggested that one or more BER proteins may also participate in epigenetic regulation to facilitate gene expression modulation via alteration of the state of DNA methylation or via a reaction coupled to histone modification. BER proteins have also been reported to play an essential role in pluripotent stem cell reprogramming. Critical Issues: One emerging function for BER in epigenetic regulation is the repair of base lesions induced by hydrogen peroxide as a byproduct of lysine-specific demethylase 1 (LSD1) enzymatic activity (LSD1/LSD2-coupled BER) for transcriptional regulation. Future Directions: To shed light on this novel role of BER, this review focuses on the repair of oxidative lesions in nuclear DNA that are induced during LSD1-mediated histone demethylation. Further, we highlight current studies suggesting a role for BER proteins in transcriptional regulation of gene expression via BER-coupled active DNA demethylation in mammalian cells. Such efforts to address the role of BER proteins in epigenetic regulation could broaden cancer therapeutic strategies to include epigenetic modifiers combined with BER inhibitors. Antioxid. Redox Signal. 18, 2429–2443. PMID:23311711

Patient-Reported Roles, Preferences, and Expectations Regarding Treatment of Stage I Rectal Cancer in the Cancer Care Outcomes Research and Surveillance Consortium.

PubMed

Tyler Ellis, C; Charlton, Mary E; Stitzenberg, Karyn B

2016-10-01

Historically, stage I rectal cancer was treated with total mesorectal excision. However, there has been growing use of local excision, with and without adjuvant therapy, to treat these early rectal cancers. Little is known about how patients and providers choose among the various treatment approaches. The purpose of this study was to identify patient roles, preferences, and expectations as they relate to treatment decision making for patients with stage I rectal cancer. This is a population-based study. The study included a geographically diverse population and health-system-based cohort. A total of 154 adults with newly diagnosed and surgically treated stage I rectal cancer between 2003 and 2005 were included. We compared patients by surgical treatment groups, including total mesorectal excision and local excision. Clinical, sociodemographic, and health-system factors were assessed for association with patient decision-making preferences and expectations. A total of 80% of patients who underwent total mesorectal excision versus 63% of patients who underwent local excision expected that surgery would be curative (p = 0.04). The total mesorectal excision group was less likely to report that radiation would cure their cancer compared with the local excision group (27% vs 63%; p = 0.004). When asked about their preferred role in decision making, 28% of patients who underwent total mesorectal excision preferred patient-controlled decision making compared with 48% of patients who underwent local excision (p = 0.046). However, with regard to the treatment actually received, 38% of the total mesorectal excision group reported making their own surgical decision compared with 25% of the local excision group (p = 0.18). The study was limited by its sample size. The preferred decision-making role for patients did not match the actual decision-making process. Future efforts should focus on bridging the gap between the decision-making process and patient preferences regarding various treatment approaches. This will be particularly important as newer innovative procedures play a more prominent role in the rectal cancer treatment paradigm.

Base Excision Repair of Oxidative DNA Damage

PubMed Central

David, Sheila S.; O’Shea, Valerie L.; Kundu, Sucharita

2010-01-01

Base excision repair plays an important role in preventing mutations associated with the common product of oxidative damage, 8-oxoguanine. Recent structural studies have shown that 8-oxoguanine glycosylases use an intricate series of steps to efficiently search and locate 8-oxoguanine lesions within the multitude of undamaged bases. The importance of prevention of mutations associated with 8-oxoguanine has also been illustrated by direct connections between defects in the BER glycosylase MUTYH and colorectal cancer. In addition, the properties of other guanine oxidation products and the BER glycosylases that remove them are being uncovered. This work is providing surprising and intriguing new insights into the process of base excision repair. PMID:17581577

Cellular phone collateral damage: A review of burns associated with lithium battery powered mobile devices.

PubMed

Mankowski, Peter J; Kanevsky, Jonathan; Bakirtzian, Parseh; Cugno, Sabrina

2016-06-01

The spontaneous destruction of lithium battery powered cellphones has raised concern about the safety of these devices. We present a case report and review of the literature of burn injuries sustained in association with cellular phone usage. A Medline search was performed to identify articles describing cellular phone associated thermal injuries using key search words including "burn," "burn injury," "cellular phone," "cellphone," "thermal injury," and "telephone." Articles were reviewed for etiology, location, severity and treatment. We also present a case of a burn to the upper thigh resulting from cellular phone battery malfunction. Six case reports were identified detailing burn injuries obtained from cellphone use. Half of these cases occurred from battery malfunction with second degree being the most common severity. All cases were managed conservatively except one case, which required excision and primary closure. Lithium powered cellular phones are susceptible to overheating and destruction from inadequate heat dissipation during thermal runaway. This process can be initiated by local short-circuiting from direct contact with a low resistance conductor such as keys or coins. We reinforce the importance of safe cell phone battery practices including avoiding overcharging and direct skin exposure to minimize thermal injury risk. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

Mobile large area confocal scanner for imaging tumor margins: initial testing in the pathology department

NASA Astrophysics Data System (ADS)

Abeytunge, Sanjee; Li, Yongbiao; Larson, Bjorg; Peterson, Gary; Toledo-Crow, Ricardo; Rajadhyaksha, Milind

2013-03-01

Surgical oncology is guided by examining pathology that is prepared during or after surgery. The preparation time for Mohs surgery in skin is 20-45 minutes, for head-and-neck and breast cancer surgery is hours to days. Often this results in incomplete tumor removal such that positive margins remain. However, high resolution images of excised tissue taken within few minutes can provide a way to assess the margins for residual tumor. Current high resolution imaging methods such as confocal microscopy are limited to small fields of view and require assembling a mosaic of images in two dimensions (2D) to cover a large area, which requires long acquisition times and produces artifacts. To overcome this limitation we developed a confocal microscope that scans strips of images with high aspect ratios and stitches the acquired strip-images in one dimension (1D). Our "Strip Scanner" can image a 10 x 10 mm2 area of excised tissue with sub-cellular detail in about one minute. The strip scanner was tested on 17 Mohs excisions and the mosaics were read by a Mohs surgeon blinded to the pathology. After this initial trial, we built a mobile strip scanner that can be moved into different surgical settings. A tissue fixture capable of scanning up to 6 x 6 cm2 of tissue was also built. Freshly excised breast and head-and-neck tissues were imaged in the pathology lab. The strip-images were registered and displayed simultaneously with image acquisition resulting in large, high-resolution confocal mosaics of fresh surgical tissue in a clinical setting.

Effects of Sildenafil and Tadalafil on Edema and Reactive Oxygen Species Production in an Experimental Model of Lung Ischemia-Reperfusion Injury.

PubMed

Guerra-Mora, J R; Perales-Caldera, E; Aguilar-León, D; Nava-Sanchez, C; Díaz-Cruz, A; Díaz-Martínez, N E; Santillán-Doherty, P; Torres-Villalobos, G; Bravo-Reyna, C C

Lung ischemia-reperfusion injury is characterized by formation of reactive oxygen species and cellular swelling leading to pulmonary edema and primary graft dysfunction. Phosphodiesterase 5 inhibitors could ameliorate lung ischemia-reperfusion injury by interfering in many molecular pathways. The aim of this work was to evaluate and compare the effects of sildenafil and tadalafil on edema and reactive oxygen species formation in an ex vivo nonhuman animal model of lung ischemia-reperfusion injury. Thirty-two Wistar rats were distributed, treated, perfused and the cardiopulmonary blocks were managed as follows: control group: immediate excision and reperfusion without pretreatment; ischemia reperfusion group: treatment with dimethylsulfoxide 0.9% and excision 1 hour later; sildenafil group: treatment with sildenafil (0.7 mg/kg) and excision 1 hour later; and tadalafil group: treatment with tadalafil (0.15 mg/kg) and excision 2 hours later. All cardiopulmonary blocks except control group were preserved for 8 hours and then reperfused. Pulmonary arterial pressure, pulmonary venous pressure, and capillary filtration coefficient were measured. Reactive oxygen species were measured. Edema was similar between control and sildenafil groups, but significantly greater in the ischemia-reperfusion (P ≤ .04) and tadalafil (P ≤ .003) groups compared with the sildenafil group. The malondialdehyde levels were significantly lower in the sildenafil (P ≤ .001) and tadalafil (P ≤ .001) groups than the ischemia-reperfusion group. Administration of sildenafil, but not tadalafil, decreased edema in lung ischemia-reperfusion injury. Both drugs decreased reactive oxygen species formation in a lung ischemia-reperfusion injury model. Copyright © 2017 Elsevier Inc. All rights reserved.

Ex vivo fluorescence confocal microscopy for fast evaluation of tumour margins during Mohs surgery.

PubMed

Bennàssar, A; Vilata, A; Puig, S; Malvehy, J

2014-02-01

Ex vivo fluorescence confocal microscopy (FCM) enables real-time imaging of skin morphology directly in freshly excised tissue. FCM displays wide field-of-view mosaics with cellular resolution, thus enabling a rapid bedside pathology. An application of interest is rapid detection of residual basal cell carcinoma (BCC) in skin excisions during Mohs surgery. We sought to evaluate the sensitivity and specificity of ex vivo imaging with FCM for the detection of residual BCC in Mohs tissue excisions, and to calculate the time invested up to the diagnosis for both FCM and frozen sections. Eighty consecutive BCCs were prospectively collected and the margins scanned with ex vivo FCM, including excisions with and without residual BCC of all major subtypes. Each mosaic was divided into two or four, resulting in 480 submosaics for study. Every confocal submosaic was assessed for the presence or absence of BCC and compared with standard frozen sections as the gold standard. Furthermore, the time spent for each technique was calculated and compared. The overall sensitivity and specificity of detecting residual BCC were 88% and 99%, respectively. Moreover, the new technique reduced by almost two-thirds the time invested when compared with the processing of a frozen section (P < 0·001). The results demonstrate the feasibility of confocal mosaicing microscopy in fresh tissue for rapid surgical pathology, potentially to expedite and guide Mohs surgery with high accuracy. This observation is an important step towards the goal of using real-time surgical pathology for skin tumours. © 2013 British Association of Dermatologists.

A simulation model to predict the fiscal and public health impact of a change in cigarette excise taxes.

PubMed

van Walbeek, Corné

2010-02-01

(1) To present a model that predicts changes in cigarette consumption and excise revenue in response to excise tax changes, and (2) to demonstrate that, if the industry has market power, increases in specific taxes have better tobacco control consequences than increases in ad valorem taxes. All model parameters are user-determined. The model calculates likely changes in cigarette consumption, smoking prevalence and excise tax revenues due to an excise tax change. The model is applicable to countries that levy excise tax as specific or ad valorem taxes. For a representative low-income or middle-income country a 20% excise tax increase decreases cigarette consumption and industry revenue by 5% and increases excise tax revenues by 14%, if there is no change in the net-of-tax price. If the excise tax is levied as a specific tax, the industry has an incentive to raise the net-of-tax price, enhancing the consumption-reducing impact of the tax increase. If the excise tax is levied as an ad valorem tax, the industry has no such incentive. The industry has an incentive to reduce the net-of-tax price in response to an ad valorem excise tax increase, undermining the public health and fiscal benefits of the tax increase. This paper presents a simple web-based tool that allows policy makers and tobacco control advocates to estimate the likely consumption, fiscal and mortality impacts of a change in the cigarette excise tax. If a country wishes to reduce cigarette consumption by increasing the excise tax, a specific tax structure is better than an ad valorem tax structure.

Histopathologic and immunohistochemical features of capsular tissue around failed Ahmed glaucoma valves.

PubMed

Mahale, Alka; Fikri, Fatma; Al Hati, Khitam; Al Shahwan, Sami; Al Jadaan, Ibrahim; Al Katan, Hind; Khandekar, Rajiv; Maktabi, Azza; Edward, Deepak P

2017-01-01

Impervious encapsulation around Ahmed glaucoma valve (AGV) results in surgical failure raising intraocular pressure (IOP). Dysregulation of extracellular matrix (ECM) molecules and cellular factors might contribute to increased hydraulic resistance to aqueous drainage. Therefore, we examined these molecules in failed AGV capsular tissue. Immunostaining for ECM molecules (collagen I, collagen III, decorin, lumican, chondroitin sulfate, aggrecan and keratan sulfate) and cellular factors (αSMA and TGFβ) was performed on excised capsules from failed AGVs and control tenon's tissue. Staining intensity of ECM molecules was assessed using Image J. Cellular factors were assessed based on positive cell counts. Histopathologically two distinct layers were visible in capsules. The inner layer (proximal to the AGV) showed significant decrease in most ECM molecules compared to outer layer. Furthermore, collagen III (p = 0.004), decorin (p = 0.02), lumican (p = 0.01) and chondroitin sulfate (p = 0.02) was significantly less in inner layer compared to tenon's tissue. Outer layer labelling however was similar to control tenon's for most ECM molecules. Significantly increased cellular expression of αSMA (p = 0.02) and TGFβ (p = 0.008) was detected within capsular tissue compared to controls. Our results suggest profibrotic activity indicated by increased αSMA and TGFβ expression and decreased expression of proteoglycan (decorin and lumican) and glycosaminoglycans (chondroitin sulfate). Additionally, we observed decreased collagen III which might reflect increased myofibroblast contractility when coupled with increased TGFβ and αSMA expression. Together these events lead to tissue dysfunction potentially resulting in hydraulic resistance that may affect aqueous flow through the capsular wall.

Margins in breast conserving surgery: The financial cost & potential savings associated with the new margin guidelines.

PubMed

Singer, Lauren; Brown, Eric; Lanni, Thomas

2016-08-01

In this study, we compare the indications for re-excision, the findings of additional tumor in the re-excision specimen as they relate to margin status, and costs associated with re-excision based on recent new consensus statements. A retrospective analysis was performed on 462 patients with invasive breast carcinoma who underwent at least one lumpectomy between January 2011 and December 2013. Postoperative data was analyzed based on where additional disease was found, as it relates to the margin status of the initial lumpectomy and the additional direct costs associated with additional procedures. Of the 462 patients sampled, 149 underwent a re-excision surgery (32.2%). Four patients underwent mastectomy as their second operation. In the 40 patients with additional disease found on re-excision, 36 (90.0%) of them had a positive margin on their initial lumpectomy. None of the four mastectomy patients had residual disease. The mean cost of the initial lumpectomy for all 462 patients was $2118.01 plus an additional $1801.92 for those who underwent re-excision. A positive margin was most predictive of finding residual tumor on re-excision as would be expected. Using old criteria only 0.07% (4/61) of patients who had undergone re-excision with a 'clear' margin, had additional tumor found, at a total cost of $106,354.11. Thus, the new consensus guidelines will lead to less overall cost, at no clinical risk to patients while reducing a patient's surgical risk and essentially eliminating delays in adjuvant care. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evaluation of the antibacterial activity of the Althaea officinalis L. leaf extract and its wound healing potency in the rat model of excision wound creation.

PubMed

Rezaei, Maryam; Dadgar, Zeynab; Noori-Zadeh, Ali; Mesbah-Namin, Seyed Alireza; Pakzad, Iraj; Davodian, Elham

2015-01-01

Wound is defined simply as the disruption of the biochemical, cellular, and anatomic continuity of a tissue. Plants and their extracts known as phytomedicine have immense potential for the management and treatment of wounds. Due to the undesirable side effects, in the control and treatment of the wound infections, it is recommended to use natural materials such as phytochemicals instead of chemically synthesized drugs. Thus, the aim of this research was to study the anti-microbial and wound healing potential of Althaea officinalis L. hydroalchoholic extract in comparison with ciprofloxacin, gentamicin, and penicillin antibiotics on clinical strains as well as pathogenic bacteria such as Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, and Listeria monocytogenes under in vitro conditions using micro broth dilution and disc diffusion methods. Moreover, MIC and MBC of its hydroalchoholic extract was also evaluated. The results showed that although Althaea officinalis L. extract was not effective on gram-negative bacteria but it was efficacious on gram-positive bacteria. The extract was also tested in the form of topical administration on excision wound model in rats. In the extract-treated wounds, the wound healing percent was significantly increased in comparison with controls. Based on this research, herbal extract of officinalis L. can be a great candidate for the treatment of gram-positive infections and merits further studies.

Role of base-excision repair in the treatment of childhood acute lymphoblastic leukaemia with 6-mercaptopurine and high doses of methotrexate.

PubMed

Stanczyk, M; Sliwinski, T; Trelinska, J; Cuchra, M; Markiewicz, L; Dziki, L; Bieniek, A; Bielecka-Kowalska, A; Kowalski, M; Pastorczak, A; Szemraj, J; Mlynarski, W; Majsterek, I

2012-01-24

Methotrexate (MTX) and 6-mercaptopurine (6MP) are the most commonly used drugs in the therapy of childhood acute lymphoblastic leukaemia (ALL). The main genotoxic effect of MTX resulting from inhibition of thymidylate synthase is mis-incorporation of uracil into DNA, which is considered essential for the effectiveness of the Protocol M in ALL IC BFM 2002/EURO LB 2002 regimens. In this study, we investigated the level of basal and induced DNA damage as well as the effectiveness of DNA repair in lymphocytes of children with ALL at four time-points during therapy with MTX and 6MP. To assess DNA damage and the efficacy of DNA repair we used the modified alkaline comet assay with uracil DNA glycosylase (Udg) and endonuclease III (EndoIII). In addition, we examined the induction of apoptosis in the lymphocytes of the patients during treatment. Finally, we compared the activity of base-excision repair (BER), involved in removal of both uracil and oxidized bases from DNA in lymphocytes of children with ALL and lymphocytes of healthy children. BER efficiency was estimated in an in vitro assay with cellular extracts and plasmid substrates of heteroduplex DNA with an AP-site. Our results indicate that there is a significant decrease in the efficacy of DNA repair associated with an increased level of uracil in DNA and induction of apoptosis during therapy. Moreover, it was found that the BER capacity was decreased in the lymphocytes of ALL patients in contrast to that in lymphocytes of healthy children. Thus, we suggest that an impairment of the BER pathway may play a role in the pathogenesis and therapy of childhood ALL. © 2011 Elsevier B.V. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Emin, David, E-mail: emin@unm.edu; Akhtari, Massoud; Ellingson, B. M.

We analyze the transient-dc and frequency-dependent electrical conductivities between blocking electrodes. We extend this analysis to measurements of ions’ transport in freshly excised bulk samples of human brain tissue whose complex cellular structure produces blockages. The associated ionic charge-carrier density and diffusivity are consistent with local values for sodium cations determined non-invasively in brain tissue by MRI (NMR) and diffusion-MRI (spin-echo NMR). The characteristic separation between blockages, about 450 microns, is very much shorter than that found for sodium-doped gel proxies for brain tissue, >1 cm.

High-throughput multiplexed T-cell-receptor excision circle quantitative PCR assay with internal controls for detection of severe combined immunodeficiency in population-based newborn screening.

PubMed

Gerstel-Thompson, Jacalyn L; Wilkey, Jonathan F; Baptiste, Jennifer C; Navas, Jennifer S; Pai, Sung-Yun; Pass, Kenneth A; Eaton, Roger B; Comeau, Anne Marie

2010-09-01

Real-time quantitative PCR (qPCR) targeting a specific marker of functional T cells, the T-cell-receptor excision circle (TREC), detects the absence of functional T cells and has a demonstrated clinical validity for detecting severe combined immunodeficiency (SCID) in infants. There is need for a qPCR TREC assay with an internal control to monitor DNA quality and the relative cellular content of the particular dried blood spot punch sampled in each reaction. The utility of the qPCR TREC assay would also be far improved if more tests could be performed on the same newborn screening sample. We approached the multiplexing of qPCR for TREC by attenuating the reaction for the reference gene, with focus on maintaining tight quality assurance for reproducible slopes and for prevention of sample-to-sample cross contamination. Statewide newborn screening for SCID using the multiplexed assay was implemented, and quality-assurance data were recorded. The multiplex qPCR TREC assay showed nearly 100% amplification efficiency for each of the TREC and reference sequences, clinical validity for multiple forms of SCID, and an analytic limit of detection consistent with prevention of contamination. The eluate and residual ghost from a 3.2-mm dried blood spot could be used as source material for multiplexed immunoassays and multiplexed DNA tests (Multiplex Plus), with no disruption to the multiplex TREC qPCR. Population-based SCID newborn screening programs should consider multiplexing for quality assurance purposes. Potential benefits of using Multiplex Plus include the ability to perform multianalyte profiling.

Psoralen-induced DNA adducts are substrates for the base excision repair pathway in human cells

PubMed Central

Couvé-Privat, Sophie; Macé, Gaëtane; Saparbaev, Murat K.

2007-01-01

Interstrand cross-link (ICL) is a covalent modification of both strands of DNA, which prevents DNA strand separation during transcription and replication. Upon photoactivation 8-methoxypsoralen (8-MOP+UVA) alkylates both strands of DNA duplex at the 5,6-double bond of thymidines, generating monoadducts (MAs) and ICLs. It was thought that bulky DNA lesions such as MAs are eliminated only in the nucleotide excision repair pathway. Instead, non-bulky DNA lesions are substrates for DNA glycosylases and AP endonucleases which initiate the base excision repair (BER) pathway. Here we examined whether BER might be involved in the removal of psoralen–DNA photoadducts. The results show that in human cells DNA glycosylase NEIL1 excises the MAs in duplex DNA, subsequently the apurinic/apyrimidinic endonuclease 1, APE1, removes the 3′-phosphate residue at single-strand break generated by NEIL1. The apparent kinetic parameters suggest that NEIL1 excises MAs with high efficiency. Consistent with these results HeLa cells lacking APE1 and/or NEIL1 become hypersensitive to 8-MOP+UVA exposure. Furthermore, we demonstrate that bacterial homologues of NEIL1, the Fpg and Nei proteins, also excise MAs. New substrate specificity of the Fpg/Nei protein family provides an alternative repair pathway for ICLs and bulky DNA damage. PMID:17715144

Phyllodes tumours of the breast: a consensus review

PubMed Central

Tan, Benjamin Y; Acs, Geza; Apple, Sophia K; Badve, Sunil; Bleiweiss, Ira J; Brogi, Edi; Calvo, José P; Dabbs, David J; Ellis, Ian O; Eusebi, Vincenzo; Farshid, Gelareh; Fox, Stephen B; Ichihara, Shu; Lakhani, Sunil R; Rakha, Emad A; Reis-Filho, Jorge S; Richardson, Andrea L; Sahin, Aysegul; Schmitt, Fernando C; Schnitt, Stuart J; Siziopikou, Kalliopi P; Soares, Fernando A; Tse, Gary M; Vincent-Salomon, Anne; Tan, Puay Hoon

2016-01-01

Phyllodes tumours constitute an uncommon but complex group of mammary fibroepithelial lesions. Accurate and reproducible grading of these tumours has long been challenging, owing to the need to assess multiple stratified histological parameters, which may be weighted differently by individual pathologists. Distinction of benign phyllodes tumours from cellular fibroadenomas is fraught with difficulty, due to overlapping microscopic features. Similarly, separation of the malignant phyllodes tumour from spindle cell metaplastic carcinoma and primary breast sarcoma can be problematic. Phyllodes tumours are treated by surgical excision. However, there is no consensus on the definition of an appropriate surgical margin to ensure completeness of excision and reduction of recurrence risk. Interpretive subjectivity, overlapping histological diagnostic criteria, suboptimal correlation between histological classification and clinical behaviour and the lack of robust molecular predictors of outcome make further investigation of the pathogenesis of these fascinating tumours a matter of active research. This review consolidates the current understanding of their pathobiology and clinical behaviour, and includes proposals for a rational approach to the classification and management of phyllodes tumours. PMID:26768026

Primary clitoral adenocarcinoma with secondary hypercalcemia of malignancy in a dog.

PubMed

Neihaus, Steven A; Winter, Jennifer E; Goring, Robert L; Kennedy, F A; Kiupel, Matti

2010-01-01

This report describes a primary clitoral adenocarcinoma in a dog with secondary hypercalcemia of malignancy. A 10-year-old, spayed female basset hound was evaluated for a mass protruding from the vulva. The mass was excised, and a histological diagnosis of clitoral adenocarcinoma was made. No evidence of metastasis on thoracic radiographs or abdominal ultrasound was seen. Preoperative hypercalcemia resolved following excision of the mass. Cellular features were similar to an apocrine gland anal sac adenocarcinoma, and immunohistochemistry exhibited features noted with apocrine gland anal sac adenocarcinoma. No further treatment was elected by the owner. Internal iliac lymph-node metastasis was identified 4 weeks postoperatively, and hypercalcemia recurred 8 weeks postoperatively. The dog was euthanized 22 weeks postoperatively for signs related to hypercalcemia, including polyuria/polydipsia, lethargy, and weakness. A necropsy was performed and confirmed the presence of internal iliac lymph-node metastasis. The colon, rectum, and anal sacs were grossly and histologically normal. To our knowledge, this is the first reported case of clitoral neoplasia in the dog.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kao, Shyan-Yuan, E-mail: shyan-yuan_kao@meei.harvard.edu

Mutation of parkin is one of the most prevalent causes of autosomal recessive Parkinson's disease (PD). Parkin is an E3 ubiquitin ligase that acts on a variety of substrates, resulting in polyubiquitination and degradation by the proteasome or monoubiquitination and regulation of biological activity. However, the cellular functions of parkin that relate to its pathological involvement in PD are not well understood. Here we show that parkin is essential for optimal repair of DNA damage. Parkin-deficient cells exhibit reduced DNA excision repair that can be restored by transfection of wild-type parkin, but not by transfection of a pathological parkin mutant.more » Parkin also protects against DNA damage-induced cell death, an activity that is largely lost in the pathological mutant. Moreover, parkin interacts with the proliferating cell nuclear antigen (PCNA), a protein that coordinates DNA excision repair. These results suggest that parkin promotes DNA repair and protects against genotoxicity, and implicate DNA damage as a potential pathogenic mechanism in PD.« less

Implication of SUMO E3 ligases in nucleotide excision repair.

PubMed

Tsuge, Maasa; Kaneoka, Hidenori; Masuda, Yusuke; Ito, Hiroki; Miyake, Katsuhide; Iijima, Shinji

2015-08-01

Post-translational modifications alter protein function to mediate complex hierarchical regulatory processes that are crucial to eukaryotic cellular function. The small ubiquitin-like modifier (SUMO) is an important post-translational modification that affects transcriptional regulation, nuclear localization, and the maintenance of genome stability. Nucleotide excision repair (NER) is a very versatile DNA repair system that is essential for protection against ultraviolet (UV) irradiation. The deficiencies in NER function remarkably increase the risk of skin cancer. Recent studies have shown that several NER factors are SUMOylated, which influences repair efficiency. However, how SUMOylation modulates NER has not yet been elucidated. In the present study, we performed RNAi knockdown of SUMO E3 ligases and found that, in addition to PIASy, the polycomb protein Pc2 affected the repair of cyclobutane pyrimidine dimers. PIAS1 affected both the removal of 6-4 pyrimidine pyrimidone photoproducts and cyclobutane pyrimidine dimers, whereas other SUMO E3 ligases did not affect the removal of either UV lesion.

Hepatitis B virus and hepatocellular carcinoma

PubMed Central

Arbuthnot, Patrick; Kew, Michael

2001-01-01

Chronic hepatitis B virus (HBV) infection is a major global cause of hepatocellular carcinoma (HCC). Individuals who are chronic carriers have a greater than 100-fold increased relative risk of developing the tumour. Several mechanisms of HBV-induced HCC have been proposed. Integration of HBV DNA into the genome of hepatocytes occurs commonly, although integration at cellular sites that are important for regulation of hepatocyte proliferation appears to be a rare event. Functions of the HBx protein are also potentially oncogenic. These include transcriptional activation of cellular growth regulatory genes, modulation of apoptosis and inhibition of nucleotide excision repair of damaged cellular DNA. The effects of HBx are mediated by interaction with cellular proteins and activation of cell signalling pathways. Variations in HBV genome sequences may be important in hepatocarcinogenesis, although their significance has not yet been completely elucidated. Necroinflammatory hepatic disease, which often accompanies chronic HBV infection, may contribute indirectly to hepatocyte transformation in a number of ways, including by facilitating HBV DNA integration, predisposing to the acquisition of cellular mutations and generating mutagenic oxygen reactive species. Although HCC is a malignancy with a poor prognosis, the availability of an effective vaccine against HBV infection, and its inclusion in the Expanded Programme of Immunization of many countries, augurs well for the eventual elimination of HBV-associated HCC. PMID:11454100

Genomic stability and telomere regulation in skeletal muscle tissue.

PubMed

Trajano, Larissa Alexsandra da Silva Neto; Trajano, Eduardo Tavares Lima; Silva, Marco Aurélio Dos Santos; Stumbo, Ana Carolina; Mencalha, Andre Luiz; Fonseca, Adenilson de Souza da

2018-02-01

Muscle injuries are common, especially in sports and cumulative trauma disorder, and their repair is influenced by free radical formation, which causes damages in lipids, proteins and DNA. Oxidative DNA damages are repaired by base excision repair and nucleotide excision repair, ensuring telomeric and genomic stability. There are few studies on this topic in skeletal muscle cells. This review focuses on base excision repair and nucleotide excision repair, telomere regulation and how telomeric stabilization influences healthy muscle, injured muscle, exercise, and its relationship with aging. In skeletal muscle, genomic stabilization and telomere regulation seem to play an important role in tissue health, influencing muscle injury repair. Thus, therapies targeting mechanisms of DNA repair and telomeric regulation could be new approaches for improving repair and prevention of skeletal muscle injuries in young and old people. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Ultrahigh resolution optical coherence elastography combined with a rigid micro-endoscope (Conference Presentation)

NASA Astrophysics Data System (ADS)

Fang, Qi; Curatolo, Andrea; Wijesinghe, Philip; Hamzah, Juliana; Ganss, Ruth; Noble, Peter B.; Karnowski, Karol; Sampson, David D.; Kim, Jun Ki; Lee, Wei M.; Kennedy, Brendan F.

2017-02-01

The mechanical forces that living cells experience represent an important framework in the determination of a range of intricate cellular functions and processes. Current insight into cell mechanics is typically provided by in vitro measurement systems; for example, atomic force microscopy (AFM) measurements are performed on cells in culture or, at best, on freshly excised tissue. Optical techniques, such as Brillouin microscopy and optical elastography, have been used for ex vivo and in situ imaging, recently achieving cellular-scale resolution. The utility of these techniques in cell mechanics lies in quick, three-dimensional and label-free mechanical imaging. Translation of these techniques toward minimally invasive in vivo imaging would provide unprecedented capabilities in tissue characterization. Here, we take the first steps along this path by incorporating a gradient-index micro-endoscope into an ultrahigh resolution optical elastography system. Using this endoscope, a lateral resolution of 2 µm is preserved over an extended depth-of-field of 80 µm, achieved by Bessel beam illumination. We demonstrate this combined system by imaging stiffness of a silicone phantom containing stiff inclusions and a freshly excised murine liver tissue. Additionally, we test this system on murine ribs in situ. We show that our approach can provide high quality extended depth-of-field images through an endoscope and has the potential to measure cell mechanics deep in tissue. Eventually, we believe this tool will be capable of studying biological processes and disease progression in vivo.

Multiscale nonlinear microscopy and widefield white light imaging enables rapid histological imaging of surgical specimen margins

PubMed Central

Giacomelli, Michael G.; Yoshitake, Tadayuki; Cahill, Lucas C.; Vardeh, Hilde; Quintana, Liza M.; Faulkner-Jones, Beverly E.; Brooker, Jeff; Connolly, James L.; Fujimoto, James G.

2018-01-01

The ability to histologically assess surgical specimens in real-time is a long-standing challenge in cancer surgery, including applications such as breast conserving therapy (BCT). Up to 40% of women treated with BCT for breast cancer require a repeat surgery due to postoperative histological findings of close or positive surgical margins using conventional formalin fixed paraffin embedded histology. Imaging technologies such as nonlinear microscopy (NLM), combined with exogenous fluorophores can rapidly provide virtual H&E imaging of surgical specimens without requiring microtome sectioning, facilitating intraoperative assessment of margin status. However, the large volume of typical surgical excisions combined with the need for rapid assessment, make comprehensive cellular resolution margin assessment during surgery challenging. To address this limitation, we developed a multiscale, real-time microscope with variable magnification NLM and real-time, co-registered position display using a widefield white light imaging system. Margin assessment can be performed rapidly under operator guidance to image specific regions of interest located using widefield imaging. Using simulated surgical margins dissected from human breast excisions, we demonstrate that multi-centimeter margins can be comprehensively imaged at cellular resolution, enabling intraoperative margin assessment. These methods are consistent with pathology assessment performed using frozen section analysis (FSA), however NLM enables faster and more comprehensive assessment of surgical specimens because imaging can be performed without freezing and cryo-sectioning. Therefore, NLM methods have the potential to be applied to a wide range of intra-operative applications. PMID:29761001

Involvement of DNA polymerase beta in repairing oxidative damages induced by antitumor drug adriamycin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu Shukun; Wu Mei; Zhang Zunzhen, E-mail: zhangzunzhen@163.co

2010-08-01

Adriamycin (ADM) is a widely used antineoplastic drug. However, the increasing cellular resistance has become a serious limitation to ADM clinical application. The most important mechanism related to ADM-induced cell death is oxidative DNA damage mediated by reactive oxygen species (ROS). Base excision repair (BER) is a major pathway in the repair of DNA single strand break (SSB) and oxidized base. In this study, we firstly applied the murine embryo fibroblasts wild-type (pol {beta} +/+) and homozygous pol {beta} null cell (pol {beta} -/-) as a model to investigate ADM DNA-damaging effects and the molecular basis underlying these effects. Here,more » cellular sensitivity to ADM was examined using colorimetric assay and colony forming assay. ADM-induced cellular ROS level and the alteration of superoxide dismutase (SOD) activity were measured by commercial kits. Further, DNA strand break, chromosomal damage and gene mutation were assessed by comet assay, micronucleus test and hprt gene mutation assay, respectively. The results showed that pol {beta} -/- cells were more sensitive to ADM compared with pol {beta} +/+ cells and more severe SSB and chromosomal damage as well as higher hprt gene mutation frequency were observed in pol {beta} -/- cells. ROS level in pol {beta} -/- cells increased along with decreased activity of SOD. These results demonstrated that pol {beta} deficiency could enable ROS accumulation with SOD activity decrease, further elevate oxidative DNA damage, and subsequently result in SSB, chromosome cleavage as well as gene mutation, which may be partly responsible for the cytotoxicity of ADM and the hypersensitivity of pol {beta} -/- cells to ADM. These findings suggested that pol {beta} is vital for repairing oxidative damage induced by ADM.« less

Teaching elliptical excision skills to novice medical students: a randomized controlled study comparing low- and high-fidelity bench models.

PubMed

Denadai, Rafael; Oshiiwa, Marie; Saad-Hossne, Rogério

2014-03-01

The search for alternative and effective forms of training simulation is needed due to ethical and medico-legal aspects involved in training surgical skills on living patients, human cadavers and living animals. To evaluate if the bench model fidelity interferes in the acquisition of elliptical excision skills by novice medical students. Forty novice medical students were randomly assigned to 5 practice conditions with instructor-directed elliptical excision skills' training (n = 8): didactic materials (control); organic bench model (low-fidelity); ethylene-vinyl acetate bench model (low-fidelity); chicken legs' skin bench model (high-fidelity); or pig foot skin bench model (high-fidelity). Pre- and post-tests were applied. Global rating scale, effect size, and self-perceived confidence based on Likert scale were used to evaluate all elliptical excision performances. The analysis showed that after training, the students practicing on bench models had better performance based on Global rating scale (all P < 0.0000) and felt more confident to perform elliptical excision skills (all P < 0.0000) when compared to the control. There was no significant difference (all P > 0.05) between the groups that trained on bench models. The magnitude of the effect (basic cutaneous surgery skills' training) was considered large (>0.80) in all measurements. The acquisition of elliptical excision skills after instructor-directed training on low-fidelity bench models was similar to the training on high-fidelity bench models; and there was a more substantial increase in elliptical excision performances of students that trained on all simulators compared to the learning on didactic materials.

Erosion of State Alcohol Excise Taxes in the United States.

PubMed

Naimi, Timothy S; Blanchette, Jason G; Xuan, Ziming; Chaloupka, Francis J

2018-01-01

In the United States, excessive alcohol consumption is responsible for 88,000 deaths annually and cost $249 billion, or $2.05 per drink, in 2010. Specific excise taxes, the predominant form of alcohol taxation in the United States, are based on the volume of alcohol sold rather than a percentage of price and can thus degrade over time because of inflation. The objective of this study was to describe changes in inflation-adjusted state alcohol excise taxes on a beverage-specific basis. State-level data on specific excise taxes were obtained from the Alcohol Policy Information System and the Tax Foundation. Excise tax rates were converted into the tax per standard U.S. drink (14 g of ethanol) for beer, wine, and distilled spirits, and converted into 2015 dollars using annual Consumer Price Index data. Across U.S. states, the average state alcohol excise tax per drink in 2015 was $0.03 for beer, $0.05 for distilled spirits, and $0.03 for wine. From 1991 to 2015, the average inflation-adjusted (in 2015 dollars) state alcohol excise tax rate declined 30% for beer, 32% for distilled spirits, and 27% for wine. Percentage declines in state excise taxes since their inception were more than twice as large as those from 1991 to 2015. In 2015, average state specific excise taxes were $0.05 or less per standard drink across all beverage types and have experienced substantial inflation-adjusted declines.

The interplay of mutations and electronic properties in disease-related genes

NASA Astrophysics Data System (ADS)

Shih, Chi-Tin; Wells, Stephen A.; Hsu, Ching-Ling; Cheng, Yun-Yin; Römer, Rudolf A.

2012-02-01

Electronic properties of DNA are believed to play a crucial role in many phenomena in living organisms, for example the location of DNA lesions by base excision repair (BER) glycosylases and the regulation of tumor-suppressor genes such as p53 by detection of oxidative damage. However, the reproducible measurement and modelling of charge migration through DNA molecules at the nanometer scale remains a challenging and controversial subject even after more than a decade of intense efforts. Here we show, by analysing 162 disease-related genes from a variety of medical databases with a total of almost 20,000 observed pathogenic mutations, a significant difference in the electronic properties of the population of observed mutations compared to the set of all possible mutations. Our results have implications for the role of the electronic properties of DNA in cellular processes, and hint at the possibility of prediction, early diagnosis and detection of mutation hotspots.

Adenomatous Polyposis Coli-Mediated Accumulation of Abasic DNA Lesions Lead to Cigarette Smoke Condensate-Induced Neoplastic Transformation of Normal Breast Epithelial Cells1

PubMed Central

Jaiswal, Aruna S; Panda, Harekrushna; Pampo, Christine A; Siemann, Dietmar W; Gairola, C Gary; Hromas, Robert; Narayan, Satya

2013-01-01

Adenomatous polyposis coli (APC) is a multifunctional protein having diverse cellular functions including cell migration, cell-cell adhesion, cell cycle control, chromosomal segregation, and apoptosis. Recently, we found a new role of APC in base excision repair (BER) and showed that it interacts with DNA polymerase β and 5′-flap endonuclease 1 and interferes in BER. Previously, we have also reported that cigarette smoke condensate (CSC) increases expression of APC and enhances the growth of normal human breast epithelial (MCF10A) cells in vitro. In the present study, using APC overexpression and knockdown systems, we have examined the molecular mechanisms by which CSC and its major component, Benzo[α]pyrene, enhances APC-mediated accumulation of abasic DNA lesions, which is cytotoxic and mutagenic in nature, leading to enhanced neoplastic transformation of MCF10A cells in an orthotopic xenograft model. PMID:23555190

Presurgical mapping of basal cell carcinoma or squamous cell carcinoma by confocal laser endomicroscopy compared to traditional micrographic surgery: a single-centre prospective feasibility study.

PubMed

Schulz, Alexandra; Daali, Samira; Javed, Mehreen; Fuchs, Paul Christian; Brockmann, Michael; Igressa, Alhadi; Charalampaki, Patra

2016-12-01

At present, no ideal diagnostic tools exist in the market to excise cancer tissue with the required safety margins and to achieve optimal aesthetic results using tissue-conserving techniques. In this prospective study, confocal laser endomicroscopy (CLE) and the traditional gold standard of magnifying glasses (MG) were compared regarding the boundaries of in vivo basal cell carcinoma and squamous cell carcinoma. Tumour diameters defined by both methods were measured and compared with those determined by histopathological examination. Nineteen patients were included in the study. The CLE technique was found to be superior to excisional margins based on MG only. Re-excision was required in 68% of the cases following excision based on MG evaluation, but only in 27% of the cases for whom excision margins were based on CLE. Our results are promising regarding the distinction between tumour and healthy surrounding tissue, and indicate that presurgical mapping of basal cell carcinoma and squamous cell carcinoma is possible. The tool itself should be developed further with special attention to early detection of skin cancer.

Dual CRISPR-Cas9 Cleavage Mediated Gene Excision and Targeted Integration in Yarrowia lipolytica.

PubMed

Gao, Difeng; Smith, Spencer; Spagnuolo, Michael; Rodriguez, Gabriel; Blenner, Mark

2018-05-29

CRISPR-Cas9 technology has been successfully applied in Yarrowia lipolytica for targeted genomic editing including gene disruption and integration; however, disruptions by existing methods typically result from small frameshift mutations caused by indels within the coding region, which usually resulted in unnatural protein. In this study, a dual cleavage strategy directed by paired sgRNAs is developed for gene knockout. This method allows fast and robust gene excision, demonstrated on six genes of interest. The targeted regions for excision vary in length from 0.3 kb up to 3.5 kb and contain both non-coding and coding regions. The majority of the gene excisions are repaired by perfect nonhomologous end-joining without indel. Based on this dual cleavage system, two targeted markerless integration methods are developed by providing repair templates. While both strategies are effective, homology mediated end joining (HMEJ) based method are twice as efficient as homology recombination (HR) based method. In both cases, dual cleavage leads to similar or improved gene integration efficiencies compared to gene excision without integration. This dual cleavage strategy will be useful for not only generating more predictable and robust gene knockout, but also for efficient targeted markerless integration, and simultaneous knockout and integration in Y. lipolytica. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The MO15 cell cycle kinase is associated with the TFIIH transcription-DNA repair factor.

PubMed

Roy, R; Adamczewski, J P; Seroz, T; Vermeulen, W; Tassan, J P; Schaeffer, L; Nigg, E A; Hoeijmakers, J H; Egly, J M

1994-12-16

A protein kinase activity that phosphorylates the C-terminal domain (CTD) of RNA polymerase II and is associated with the basal transcription-repair factor TFIIH (also called BTF2) resides with MO15, a cyclin-dependent protein kinase that was first found to be involved in cell cycle regulation. Using in vivo and in vitro repair assays, we show that MO15 is important for nucleotide excision repair, most likely through its association with TFIIH, thus providing an unexpected link among three important cellular mechanisms.

Teaching Elliptical Excision Skills to Novice Medical Students: A Randomized Controlled Study Comparing Low- and High-Fidelity Bench Models

PubMed Central

Denadai, Rafael; Oshiiwa, Marie; Saad-Hossne, Rogério

2014-01-01

Background: The search for alternative and effective forms of training simulation is needed due to ethical and medico-legal aspects involved in training surgical skills on living patients, human cadavers and living animals. Aims: To evaluate if the bench model fidelity interferes in the acquisition of elliptical excision skills by novice medical students. Materials and Methods: Forty novice medical students were randomly assigned to 5 practice conditions with instructor-directed elliptical excision skills’ training (n = 8): didactic materials (control); organic bench model (low-fidelity); ethylene-vinyl acetate bench model (low-fidelity); chicken legs’ skin bench model (high-fidelity); or pig foot skin bench model (high-fidelity). Pre- and post-tests were applied. Global rating scale, effect size, and self-perceived confidence based on Likert scale were used to evaluate all elliptical excision performances. Results: The analysis showed that after training, the students practicing on bench models had better performance based on Global rating scale (all P < 0.0000) and felt more confident to perform elliptical excision skills (all P < 0.0000) when compared to the control. There was no significant difference (all P > 0.05) between the groups that trained on bench models. The magnitude of the effect (basic cutaneous surgery skills’ training) was considered large (>0.80) in all measurements. Conclusion: The acquisition of elliptical excision skills after instructor-directed training on low-fidelity bench models was similar to the training on high-fidelity bench models; and there was a more substantial increase in elliptical excision performances of students that trained on all simulators compared to the learning on didactic materials. PMID:24700937

Pathobiology of Hemangiosarcoma in Dogs: Research Advances and Future Perspectives

PubMed Central

Kim, Jong-Hyuk; Graef, Ashley J.; Dickerson, Erin B.; Modiano, Jaime F.

2015-01-01

Hemangiosarcoma (HSA) is an aggressive and common cancer in dogs. While cutaneous masses are often treatable by tumor excision, visceral tumors are almost always incurable. Treatment advances for this disease have been limited due to a poor understanding of the overall tumor biology. Based upon its histological appearance, HSA has been presumed to originate from transformed endothelial cells; however, accumulating data now suggest a pluripotent bone marrow progenitor as the cell of origin for this disease. More recently, the identification of a novel subclassification of HSAs has provided a foundation to further our understanding of the cellular characteristics of HSA tumor cells, along with those of the cells comprising the tumor microenvironment. These discoveries hold promise for the development of new approaches to improve treatments for canine HSA, as well as to establish the utility of this disease as a spontaneous model to understand the pathogenesis and develop new treatments for vascular tumors of humans. In this review, we will provide a brief historical perspective and pathobiology of canine HSA, along with a focus on the recent advances in the molecular and cellular understanding of these tumors. In addition, future directions that should continue to improve our understanding of HSA pathogenesis will be discussed. PMID:29061949

A damaged DNA binding protein 2 mutation disrupting interaction with proliferating-cell nuclear antigen affects DNA repair and confers proliferation advantage.

PubMed

Perucca, Paola; Mocchi, Roberto; Guardamagna, Isabella; Bassi, Elisabetta; Sommatis, Sabrina; Nardo, Tiziana; Prosperi, Ennio; Stivala, Lucia Anna; Cazzalini, Ornella

2018-06-01

In mammalian cells, Nucleotide Excision Repair (NER) plays a role in removing DNA damage induced by UV radiation. In Global Genome-NER subpathway, DDB2 protein forms a complex with DDB1 (UV-DDB), recognizing photolesions. During DNA repair, DDB2 interacts directly with PCNA through a conserved region in N-terminal tail and this interaction is important for DDB2 degradation. In this work, we sought to investigate the role of DDB2-PCNA association in DNA repair and cell proliferation after UV-induced DNA damage. To this end, stable clones expressing DDB2 Wt and DDB2 PCNA- were used. We have found that cells expressing a mutant DDB2 show inefficient photolesions removal, and a concomitant lack of binding to damaged DNA in vitro. Unexpected cellular behaviour after DNA damage, such as UV-resistance, increased cell growth and motility were found in DDB2 PCNA- stable cell clones, in which the most significant defects in cell cycle checkpoint were observed, suggesting a role in the new cellular phenotype. Based on these findings, we propose that DDB2-PCNA interaction may contribute to a correct DNA damage response for maintaining genome integrity. Copyright © 2018 Elsevier B.V. All rights reserved.

An Automated Energy Detection Algorithm Based on Kurtosis-Histogram Excision

DTIC Science & Technology

2018-01-01

ARL-TR-8269 ● JAN 2018 US Army Research Laboratory An Automated Energy Detection Algorithm Based on Kurtosis-Histogram Excision...needed. Do not return it to the originator. ARL-TR-8269 ● JAN 2018 US Army Research Laboratory An Automated Energy Detection...collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources

Ultrahigh-resolution optical coherence elastography through a micro-endoscope: towards in vivo imaging of cellular-scale mechanics

PubMed Central

Fang, Qi; Curatolo, Andrea; Wijesinghe, Philip; Yeow, Yen Ling; Hamzah, Juliana; Noble, Peter B.; Karnowski, Karol; Sampson, David D.; Ganss, Ruth; Kim, Jun Ki; Lee, Woei M.; Kennedy, Brendan F.

2017-01-01

In this paper, we describe a technique capable of visualizing mechanical properties at the cellular scale deep in living tissue, by incorporating a gradient-index (GRIN)-lens micro-endoscope into an ultrahigh-resolution optical coherence elastography system. The optical system, after the endoscope, has a lateral resolution of 1.6 µm and an axial resolution of 2.2 µm. Bessel beam illumination and Gaussian mode detection are used to provide an extended depth-of-field of 80 µm, which is a 4-fold improvement over a fully Gaussian beam case with the same lateral resolution. Using this system, we demonstrate quantitative elasticity imaging of a soft silicone phantom containing a stiff inclusion and a freshly excised malignant murine pancreatic tumor. We also demonstrate qualitative strain imaging below the tissue surface on in situ murine muscle. The approach we introduce here can provide high-quality extended-focus images through a micro-endoscope with potential to measure cellular-scale mechanics deep in tissue. We believe this tool is promising for studying biological processes and disease progression in vivo. PMID:29188108

Reactive oxygen species regulate DNA copy number in isolated yeast mitochondria by triggering recombination-mediated replication.

PubMed

Hori, Akiko; Yoshida, Minoru; Shibata, Takehiko; Ling, Feng

2009-02-01

Mitochondrial DNA (mtDNA) encodes proteins that are essential for cellular ATP production. Reactive oxygen species (ROS) are respiratory byproducts that damage mtDNA and other cellular components. In Saccharomyces cerevisiae, the oxidized base excision-repair enzyme Ntg1 introduces a double-stranded break (DSB) at the mtDNA replication origin ori5; this DSB initiates the rolling-circle mtDNA replication mediated by the homologous DNA pairing protein Mhr1. Thus, ROS may play a role in the regulation of mtDNA copy number. Here, we show that the treatment of isolated mitochondria with low concentrations of hydrogen peroxide increased mtDNA copy number in an Ntg1- and Mhr1-dependent manner. This treatment elevated the DSB levels at ori5 of hypersuppressive [rho(-)] mtDNA only if Ntg1 was active. In vitro Ntg1-treatment of hypersuppressive [rho(-)] mtDNA extracted from hydrogen peroxide-treated mitochondria revealed increased oxidative modifications at ori5 loci. We also observed that purified Ntg1 created breaks in single-stranded DNA harboring oxidized bases, and that ori5 loci have single-stranded character. Furthermore, chronic low levels of hydrogen peroxide increased in vivo mtDNA copy number. We therefore propose that ROS act as a regulator of mtDNA copy number, acting through the Mhr1-dependent initiation of rolling-circle replication promoted by Ntg1-induced DSB in the single-stranded regions at ori5.

[Transanal total mesorectal excision for rectal cancer - just a fashion trend?].

PubMed

Kala, Z; Skrovina, M; Procházka, V; Grolich, T; Klos, K

2014-12-01

Transanal total mesorectal excision performed using equipment for transanal minimally invasive surgery is an innovative surgical technique introduced to facilitate this procedure and to reach better oncosurgical outcomes in patients with low rectal cancer. This article presents a brief summary of guidelines for treatment of patients with low rectal carcinoma. Up-to-date information about the principles of this new method, its modifications and contemporary indications is presented. Based on their own experience and literature resources, the authors inform about the advantages, limitations and unresolved issues of minimally invasive transanal mesorectal excision.

Subcutaneous hemangiosarcoma induced by a foreign body (steel staple) in a cat.

PubMed

Tan, Rommel Max; Singh, Kuldeep; Sandman, Kristi

2013-04-01

An 8-year-old, female domestic shorthair cat was presented with a ventral abdominal subcutaneous mass. A radiograph showed that the center of the mass contained what appeared to be steel sutures, presumed to be from an ovariohysterectomy performed 7 years earlier. The excised mass was irregular and contained numerous pockets filled with friable necrotic material and hemorrhages that were dissected by fibrous connective tissue bands. Multiple tangled and fragmented pieces of steel staples were deeply embedded within the mass. Histologically, the mass was non-encapsulated, densely cellular, and infiltrative. Neoplastic cells lined caverns and channels and were factor VIII-positive by immunohistochemistry. The neoplastic cells were oval to round with granular cytoplasm and vesicular nucleus and exhibited moderate cellular and nuclear pleomorphism. A diagnosis of subcutaneous hemangiosarcoma was made. To our knowledge, this is the first report of foreign body associated hemangiosarcoma and the first case of steel staple associated neoplasm in domestic animals.

Fine-needle aspiration cytology of malignant hemangiopericytoma of the salivary gland: A case report.

PubMed

Shimizu, K; Ogura, S; Kobayashi, T K; Kushima, R; Toyokuni, S; Iwasa, Y; Sakurai, M

1999-12-01

A 79-yr-old woman presented with a 5-yr history of swelling of the left cheek. The fine-needle aspiration (FNA) smear showed a spindle-cell neoplasm with capillaries and benign endothelial cells. The spindle cells possessed pleomorphic, hyperchromatic elongated nuclei and a moderate amount of ill-defined cytoplasm. They also showed papillary arcades surrounded and encased by relatively small ovoid to short spindle cells. Subsequent surgical excision confirmed the presence of malignant hemangiopericytoma (HP). Immunohistochemical studies on the histologic section using vimentin were strongly positive, consistent with HP. To the best of our knowledge, this is the second published report of FNA cellular features of malignant HP of the salivary gland. Besides delineating the FNA cellular features of HP of the salivary gland, the present case illustrates the value of using immunohistochemical approaches. Diagn. Cytopathol. 1999;21:398-401. Copyright 1999 Wiley-Liss, Inc.

Subungual and periungual congenital blue naevus.

PubMed

Gershtenson, Platina Coy; Krunic, Aleksandar; Chen, Helen; Konanahalli, Madhuri; Worobec, Sophie

2009-05-01

Subungual pigmented lesions should raise concern about malignant melanoma. Blue naevus of the nail apparatus is a rare entity, with only ten cases described in the literature. We report a 21-year-old Hispanic woman with a slowly enlarging 1.7 x 2.3-cm subungual and periungual pigmented plaque present since birth on her right second toe. Initial biopsy was consistent with a blue naevus of the cellular type and, given the recent clinical change and periungual extension, complete excision was recommended. The entire nail unit was resected down to periosteum with prior avulsion of the nail plate. Reconstruction was performed with a full-thickness skin graft. Follow up at 1 year revealed well-healed graft and donor sites with complete return of function. We present a case of a congenital subungual and periungual blue naevus of the cellular type and review the literature on this rare presentation of a congenital blue naevus.

Effects of methyl and inorganic mercury exposure on genome homeostasis and mitochondrial function in Caenorhabditis elegans.

PubMed

Wyatt, Lauren H; Luz, Anthony L; Cao, Xiou; Maurer, Laura L; Blawas, Ashley M; Aballay, Alejandro; Pan, William K Y; Meyer, Joel N

2017-04-01

Mercury toxicity mechanisms have the potential to induce DNA damage and disrupt cellular processes, like mitochondrial function. Proper mitochondrial function is important for cellular bioenergetics and immune signaling and function. Reported impacts of mercury on the nuclear genome (nDNA) are conflicting and inconclusive, and mitochondrial DNA (mtDNA) impacts are relatively unknown. In this study, we assessed genotoxic (mtDNA and nDNA), metabolic, and innate immune impacts of inorganic and organic mercury exposure in Caenorhabditis elegans. Genotoxic outcomes measured included DNA damage, DNA damage repair (nucleotide excision repair, NER; base excision repair, BER), and genomic copy number following MeHg and HgCl 2 exposure alone and in combination with known DNA damage-inducing agents ultraviolet C radiation (UVC) and hydrogen peroxide (H 2 O 2 ), which cause bulky DNA lesions and oxidative DNA damage, respectively. Following exposure to both MeHg and HgCl 2 , low-level DNA damage (∼0.25 lesions/10kb mtDNA and nDNA) was observed. Unexpectedly, a higher MeHg concentration reduced damage in both genomes compared to controls. However, this observation was likely the result of developmental delay. In co-exposure treatments, both mercury compounds increased initial DNA damage (mtDNA and nDNA) in combination with H 2 O 2 exposure, but had no impact in combination with UVC exposure. Mercury exposure both increased and decreased DNA damage removal via BER. DNA repair after H 2 O 2 exposure in mercury-exposed nematodes resulted in damage levels lower than measured in controls. Impacts to NER were not detected. mtDNA copy number was significantly decreased in the MeHg-UVC and MeHg-H 2 O 2 co-exposure treatments. Mercury exposure had metabolic impacts (steady-state ATP levels) that differed between the compounds; HgCl 2 exposure decreased these levels, while MeHg slightly increased levels or had no impact. Both mercury species reduced mRNA levels for immune signaling-related genes, but had mild or no effects on survival on pathogenic bacteria. Overall, mercury exposure disrupted mitochondrial endpoints in a mercury-compound dependent fashion. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of methyl and inorganic mercury exposure on genome homeostasis and mitochondrial function in Caenorhabditis elegans

PubMed Central

Wyatt, Lauren H.; Luz, Anthony L.; Cao, Xiou; Maurer, Laura L.; Blawas, Ashley M.; Aballay, Alejandro; Pan, William K.; Meyer, Joel N.

2017-01-01

Mercury toxicity mechanisms have the potential to induce DNA damage and disrupt cellular processes, like mitochondrial function. Proper mitochondrial function is important for cellular bioenergetics and immune signaling and function. Impacts of mercury on the nuclear genome (nDNA) are conflicting and inconclusive, and mitochondrial DNA (mtDNA) impacts are relatively unknown. In this study, we assessed genotoxic (mtDNA and nDNA), metabolic, and innate immune impacts of inorganic and organic mercury exposure in Caenorhabditis elegans. Genotoxic outcomes measured included DNA damage, DNA damage repair (nucleotide excision repair, NER; base excision repair, BER), and genomic copy number following MeHg and HgCl2 exposure alone and in combination with known DNA damage-inducing agents ultraviolet C radiation (UVC) and hydrogen peroxide (H2O2), which cause bulky DNA lesions and oxidative DNA damage, respectively. Following exposure to both MeHg and HgCl2, low-level DNA damage (~0.25 lesions/10 kb mtDNA and nDNA) was observed. Unexpectedly, a higher MeHg concentration reduced damage in both genomes compared to controls. However, this observation was likely the result of developmental delay. In co-exposure treatments, both mercury compounds increased initial DNA damage (mtDNA and nDNA) in combination with H2O2 exposure, but had no impact in combination with UVC exposure. Mercury exposure both increased and decreased DNA damage removal via BER. DNA repair after H2O2 exposure in mercury-exposed nematodes resulted in damage levels lower than measured in controls. Impacts to NER were not detected. mtDNA copy number was significantly decreased in the MeHg-UVC and MeHg-H2O2 co-exposure treatments. Mercury exposure had metabolic impacts (steady-state ATP levels) that differed between the compounds; HgCl2 exposure decreased these levels, while MeHg slightly increased levels or had no impact. Both mercury species reduced mRNA levels for immune signaling-related genes, but had mild or no effects on survival on pathogenic bacteria. Overall, mercury exposure disrupted mitochondrial endpoints in a mercury-compound dependent fashion. PMID:28242054

Ocular and periocular hemangiosarcoma in six horses.

PubMed

Scherrer, Nicole M; Lassaline, Mary; Engiles, Julie

2017-11-07

To determine the characteristics of and prognosis for ocular and periocular hemangiosarcoma in horses. Six horses treated for ocular or periocular hemangiosarcoma. A retrospective review of medical records from 2007 to 2015 was performed to identify horses with a histologic diagnosis of ocular or periocular hemangiosarcoma. Signalment (age, sex, breed), duration of clinical signs, prior treatment, tumor size and location, medical and surgical treatment including postoperative chemotherapy, follow-up time, and outcome were obtained from medical records. Histopathology was reviewed by a board-certified pathologist. In six horses diagnosed with ocular or periocular hemangiosarcoma, no breed, age, or sex was overrepresented. Sites included the temporal limbus (3), third eyelid (2), and uvea (1). With the exception of one horse with uveal hemangiosarcoma, 5/6 horses had lightly pigmented periocular haircoat. Histologic features of ocular hemangiosarcoma in 6/6 cases included high cellularity, nuclear pleomorphism, and inflammation with a mitotic index ranging from 0 to 8 mitoses per 10 consecutive 400× fields. Five of six tumors displayed solar elastosis, indicating ultraviolet light-induced damage to sub-epithelial collagen. Treatment included surgical excision in all cases and was not associated with recurrence in 4/6. Three cases that received ancillary treatment with topical mitomycin C had no postoperative recurrence. Two cases with postexcisional recurrence had histologic evidence of incomplete excision. Complete surgical excision may be associated with resolution of periocular and ocular hemangiosarcoma in horses. Etiopathogenesis may include exposure to ultraviolet light. © 2017 American College of Veterinary Ophthalmologists.

Planning the breast tumor bed boost: Changes in the excision cavity volume and surgical scar location after breast-conserving surgery and whole-breast irradiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oh, Kevin S.; Kong, F.-M.; Griffith, Kent A.

2006-11-01

Purpose: The aims of this study were to determine the changes in breast and excision cavity volumes after whole-breast irradiation and the adequacy of using the surgical scar to guide boost planning. Methods and Materials: A total of 30 women consecutively treated for 31 breast cancers were included in this study. Simulation CT scans were performed before and after whole-breast irradiation. CT breast volumes were delineated using clinically defined borders. Excision cavity volumes were contoured based on surgical clips, the presence of a hematoma, and/or other surgical changes. Hypothetical electron boost plans were generated using the surgical scar with amore » 3-cm margin and analyzed for coverage. Results: The mean CT breast volumes were 774 and 761 cc (p = 0.22), and the excision cavity volumes were 32.1 and 25.1 cc (p < 0.0001), before and after 40 Gy (39-42 Gy) of whole-breast irradiation, respectively. The volume reduction in the excision cavity was inversely correlated with time elapsed since surgery (R = 0.46, p < 0.01) and body weight (R = 0.50, p < 0.01). The scar-guided hypothetical plans failed to cover the excision cavity adequately in 62% and 53.8% of cases using the pretreatment and postradiation CTs, respectively. Per the hypothetical plans, the minimum dose to the excision cavity was significantly lower for tumors located in the inner vs. outer quadrants (p = 0.02) and for cavities >20 cc vs. <20 cc (p = 0.01). Conclusions: This study demonstrates a significant reduction in the volume of the excision cavity during whole-breast irradiation. Scar-guided boost plans provide inadequate coverage of the excision cavity in the majority of cases.« less

Is surgical excision necessary for the treatment of Granulomatous lobular mastitis?

PubMed

Shin, Young Duck; Park, Sung Su; Song, Young Jin; Son, Seung-Myoung; Choi, Young Jin

2017-07-24

We aimed to investigate the role of surgical excision in treating granulomatous lobular mastitis. We performed a retrospective chart review of patients with granulomatous lobular mastitis treated from March 2008 to March 2014. We analyzed clinical features and therapeutic modalities and compared the patient outcomes based on treatment. During the study period, a total of 34 patients were diagnosed with granulomatous lobular mastitis and treated. Initial treatments included wide excision (18), oral steroids after incision and drainage (14), and antibiotic therapy (2). The patients receiving only antibiotic therapy showed no improvement after 1 month and wide excision was then performed. Wide excision resulted in nine case of delayed wound healing with fistula. These patients were treated with oral steroids for 1.5-5 months, with subsequent improvement. Overall, 11 out of 20 patients who had underwent wide excision showed improvement without additional treatment. Fourteen patients who had initially received oral steroids for 1 to 6 months (average, 2.8 months) after incision and drainage showed complete remission. During the median follow-up period with 45.5 months (range, 22-98 months), six patients (17.6%) experienced recurrence. Wide excision group experienced recurrence in five (25%) and steroid and drainage group experienced recurrence in one (7.1%). All six recurrences responded to additional steroid therapy for average 3.5 months. Most wide excision group left extensive breast scarring with deformation that was not in steroid and drainage group. Wide excision resulted high recurrence than steroid and drainage group and left extensive scarring. Steroid therapy with or without abscess drainage may be the first choice of treatment for majority cases with granulomatous lobular mastitis.

Enhanced Mitochondrial DNA Repair of the Common Disease-Associated Variant, Ser326Cys, of hOGG1 through Small Molecule Intervention.

PubMed

Baptiste, Beverly A; Katchur, Steven R; Fivenson, Elayne M; Croteau, Deborah L; Rumsey, William L; Bohr, Vilhelm A

2018-06-04

The common oxidatively generated lesion, 8-oxo-7,8-dihydroguanine (8-oxoGua), is removed from DNA by base excision repair. The glycosylase primarily charged with recognition and removal of this lesion is 8-oxoGuaDNA glycosylase 1 (OGG1). When left unrepaired, 8-oxodG alters transcription and is mutagenic. Individuals homozygous for the less active OGG1 allele, Ser326Cys, have increased risk of several cancers. Here, small molecule enhancers of OGG1 were identified and tested for their ability to stimulate DNA repair and protect cells from the environmental hazard paraquat (PQ). PQ-induced mtDNA damage was inversely proportional to the levels of OGG1 expression whereas stimulation of OGG1, in some cases, entirely abolished its cellular effects. The PQ-mediated decline of mitochondrial membrane potential or nuclear condensation were prevented by the OGG1 activators. In addition, in Ogg1 -/- mouse embryonic fibroblasts complemented with hOGG1 S326C , there was increased cellular and mitochondrial reactive oxygen species compared to their wild type counterparts. Mitochondrial extracts from cells expressing hOGG1 S326C were deficient in mitochondrial 8-oxodG incision activity, which was rescued by the OGG1 activators. These data demonstrate that small molecules can stimulate OGG1 activity with consequent cellular protection. Thus, OGG1-activating compounds may be useful in select humans to mitigate the deleterious effects of environmental oxidants and mutagens. Copyright © 2018 Elsevier Inc. All rights reserved.

Minimally invasive endoscope-assisted trans-oral excision of huge parapharyngeal space tumors.

PubMed

Li, Shang-Yi; Hsu, Ching-Hui; Chen, Mu-Kuan

2015-04-01

Parapharyngeal space tumors are rare head and neck neoplasms, and most are benign lesions. Complete excision of these tumors is difficult because of the complexity of the surrounding anatomic structures. The algorithm for excision of these tumors is typically based on the tumor's characteristics; excision is performed via approaches such as the trans-oral route, the trans-cervical route, and even a combination of the trans-parotid route and mandibulotomy. However, each of these approaches is associated with some complications. Endoscope-assisted minimally invasive surgery is being increasingly employed for surgeries in the head and neck regions. It has the advantage of leaving no facial scars, and ensures better patient comfort after the operation. Here, we report the use of endoscope-assisted trans-oral surgery for excision of parapharyngeal space tumors. The technique yields an excellent outcome and should be a feasible, safe, and economic method for these patients. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Is initial excision of cutaneous melanoma by General Practitioners (GPs) dangerous? Comparing patient outcomes following excision of melanoma by GPs or in hospital using national datasets and meta-analysis.

PubMed

Murchie, Peter; Amalraj Raja, Edwin; Brewster, David H; Iversen, Lisa; Lee, Amanda J

2017-11-01

Melanomas are initially excised in primary care, and rates vary internationally. Until now, there has been no strong evidence one way or the other that excising melanomas in primary care is safe or unsafe. European guidelines make no recommendations, and the United Kingdom (UK) melanoma guidelines require all suspicious skin lesions to be initially treated in secondary care based on an expert consensus, which lacks supporting evidence, that primary care excision represents substandard care. Despite this, studies have found that up to 20% of melanomas in the UK are excised by general practitioners (GPs). Patients receiving primary care melanoma excision may fear that their care is substandard and their long-term survival threatened, neither of which may be justified. Scottish cancer registry data from 9367 people diagnosed with melanoma in Scotland between 2005 and 2013 were linked to pathology records, hospital data and death records. A Cox proportional hazards regression analysis, adjusting for key confounders, explored the association between morbidity and mortality and setting of primary melanoma excision (primary versus secondary care). A pooled estimate of the relative hazard of death of having a melanoma excised in primary versus secondary care including 7116 patients from a similar Irish study was also performed. The adjusted hazard ratio (95% CI) of death from melanoma for those having primary care excision was 0.82 (0.61-1.10). Those receiving primary care excision had a median (IQR) of 8 (3-14) out-patient attendances compared to 10 (4-17) for the secondary care group with an adjusted relative risk (RR) (95% CI) of 0.98 (0.96-1.01). Both groups had a median of 1 (0-2) hospital admissions with an adjusted rate ratio of 1.05 (0.98-1.13). In the meta-analysis, with primary care as the reference, the pooled adjusted hazard ratio (HR, 95% CI) was 1.26 (1.07-1.50) indicating a significantly higher all-cause mortality among those with excision in secondary care. The results of the Scottish and pooled analyses suggest that those receiving an initial excision for melanoma in primary care do not have poorer survival or increased morbidity compared to those being initially treated in secondary care. A randomised controlled trial to inform a greater role for GPs in the initial excision of melanoma is justified in the light of these results. Copyright © 2017 Elsevier Ltd. All rights reserved.

An Automated Energy Detection Algorithm Based on Consecutive Mean Excision

DTIC Science & Technology

2018-01-01

present in the RF spectrum. 15. SUBJECT TERMS RF spectrum, detection threshold algorithm, consecutive mean excision, rank order filter , statistical...Median 4 3.1.9 Rank Order Filter (ROF) 4 3.1.10 Crest Factor (CF) 5 3.2 Statistical Summary 6 4. Algorithm 7 5. Conclusion 8 6. References 9...energy detection algorithm based on morphological filter processing with a semi- disk structure. Adelphi (MD): Army Research Laboratory (US); 2018 Jan

Efficacy of doxorubicin-based chemotherapy for non-resectable canine subcutaneous haemangiosarcoma.

PubMed

Wiley, J L; Rook, K A; Clifford, C A; Gregor, T P; Sorenmo, K U

2010-09-01

Eighteen dogs with measurable subcutaneous haemangiosarcoma (SQHSA) were treated with doxorubicin-based chemotherapy. Response assessment was evaluated and compared using World Health Organization (WHO), Response Evaluation Criteria in Solid Tumours (RECIST) and tumour volume criteria. The overall response rate for all dogs was 38.8% using WHO criteria, 38.8% using RECIST criteria and 44% using tumour volume criteria. One dog had a complete response. The median response duration for all dogs was 53 days (range 13-190 days). Four dogs had complete surgical excision after neoadjuvant chemotherapy. The median progression-free interval for dogs with complete surgical excision after neoadjuvant chemotherapy was significantly longer than those not having surgical excision (207 days versus 83 days, respectively) (P = 0.003). No significant difference in metastasis-free interval or survival time was found between the groups. Doxorubicin-based chemotherapy appears to be effective for non-resectable canine SQHSA, although the response duration is relatively short.

Analysis of soybean tissue culture protein dynamics using difference gel electrophoresis.

PubMed

Miernyk, Ján A; Jett, Alissa A; Johnston, Mark L

2016-01-01

Excised hypocotyls from developing soybean (Glycine max (L.) merr. cv. Jack) were cultivated on agar-solidified medium until callus formed. The calli were then propagated in liquid medium until stable, relatively uniform, finely-divided suspension cultures were obtained. Cells were typically transferred to fresh medium at 7-day intervals. Cultures were harvested by filtration five days (early log phase) or eight days (late log phase) after transfer. In order to evaluate dynamic changes, both intracellular and extracellular proteins were analyzed by 2-dimensional difference gel electrophoresis. Selected spots were subjected to in-gel tryptic-digestion and the resultant peptides were analyzed by nLC-MS/MS. In follow-up studies gel-free shot-gun analyses led to identification of 367 intracellular proteins and 188 extracellular proteins. The significance of the described research is two-fold. First a gel-based proteomics method was applied to the study of the dynamics of the secretome (extracellular proteins). Second, results of a shot-gun non-gel based proteomic survey of both cellular and extracellular proteins are presented. Published by Elsevier B.V.

Florid juvenile (cellular) fibroadenomatosis in the adolescent: a case for subcutaneous mastectomy?

PubMed

Silfen, R; Skoll, P J; Hudson, D A

1999-01-01

Juvenile or giant fibroadenoma (JF) is an uncommon fibroadenoma variant usually presenting in adolescence. Although these masses are benign, when multiple and bilateral, they present a complex challenge to the attending surgeon, both in diagnosis, and in selection of the most appropriate therapy. Treatment is usually surgical and ranges from simple excision to subcutaneous mastectomy with reconstruction. We report an unusual case of refractory JF, initially treated with combined hormonal and surgical treatment but ultimately requiring bilateral subcutaneous mastectomies to prevent tumor regrowth. This case highlights the occasional difficulty in the management of macromastia in the adolescent female.

Feline vaccine-associated fibrosarcoma induced by aluminium compound in two cats: short communication.

PubMed

Deim, Zoltán; Palmai, Nimród; Cserni, Gábor

2008-03-01

Two cases of feline vaccine-associated fibrosarcoma (FVAF) are reported. The excised tumours were both characterised as well circumscribed, subcutaneous, firm and white with central necrosis. Histopathologically, they consisted of well-differentiated and variably sized and shaped anaplastic cells, characterised by marked nuclear and cellular pleomorphism including giant cells. The mitotic activity was low. Aluminium was demonstrated in the central necrosis and giant cells. Neoplastic cells were positive for vimentin and negative for desmin and cytokeratin. The presence of feline sarcoma virus and feline immunodeficiency virus could not be detected by PCR in either case.

Multimodal confocal mosaics enable high sensitivity and specificity in screening of in situ squamous cell carcinoma

NASA Astrophysics Data System (ADS)

Grados Luyando, Maria del Carmen; Bar, Anna; Snavely, Nicholas; Jacques, Steven; Gareau, Daniel S.

2014-02-01

Screening cancer in excision margins with confocal microscopy may potentially save time and cost over the gold standard histopathology (H and E). However, diagnostic accuracy requires sufficient contrast and resolution to reveal pathological traits in a growing set of tumor types. Reflectance mode images structural details due to microscopic refractive index variation. Nuclear contrast with acridine orange fluorescence provides enhanced diagnostic value, but fails for in situ squamous cell carcinoma (SCC), where the cytoplasm is important to visualize. Combination of three modes [eosin (Eo) fluorescence, reflectance (R) and acridine orange (AO) fluorescence] enable imaging of cytoplasm, collagen and nuclei respectively. Toward rapid intra-operative pathological margin assessment to guide staged cancer excisions, multimodal confocal mosaics can image wide surgical margins (~1cm) with sub-cellular resolution and mimic the appearance of conventional H and E. Absorption contrast is achieved by alternating the excitation wavelength: 488nm (AO fluorescence) and 532nm (Eo fluorescence). Superposition and false-coloring of these modes mimics H and E, enabling detection of the carcinoma in situ in the epidermal layer The sum mosaic Eo+R is false-colored pink to mimic eosins' appearance in H and E, while the AO mosaic is false-colored purple to mimic hematoxylins' appearance in H and E. In this study, mosaics of 10 Mohs surgical excisions containing SCC in situ and 5 containing only normal tissue were subdivided for digital presentation equivalent to 4X histology. Of the total 16 SCC in situ multimodal mosaics and 16 normal cases presented, two reviewers made 1 and 2 (respectively) type-2 errors (false positives) but otherwise scored perfectly when using the confocal images to screen for the presence of SCC in situ as compared to the gold standard histopathology. Limitations to precisely mimic H and E included occasional elastin staining by AO. These results suggest that confocal mosaics may effectively guide staged SCC excisions in skin and other tissues.

Pharmacodynamic Assay Panel for Monitoring Phospho-Signaling Networks | Office of Cancer Clinical Proteomics Research

Cancer.gov

The DNA damage response (DDR) is a highly regulated signal transduction network that orchestrates the temporal and spatial organization of protein complexes required to repair (or tolerate) DNA damage (e.g., nucleotide excision repair, base excision repair, homologous recombination, non-homologous end joining, post-replication repair).

The impact of use of an intraoperative margin assessment device on re-excision rates.

PubMed

Sebastian, Molly; Akbari, Stephanie; Anglin, Beth; Lin, Erin H; Police, Alice M

2015-01-01

Historically there has been a high rate of surgical interventions to obtain clear margins for breast cancer patients undergoing breast conserving local therapy. An intraoperative margin assessment tool (MarginProbe) has been approved for use in the US since 2013. This study is the first compilation of data from routine use of the device, to assess the impact of device utilization on re-excision rates. We present a retrospective, observational, review from groups of consecutive patients, before and after the implementation of intraoperative use of the device during lumpectomy procedures. Lesions were localized by standard methods. The intraoperative margin assessment device was used on all circumferential margins of the main specimen, but not on any additional shavings. A positive reading by the device led to an additional shaving of the corresponding cavity location. Specimens were also, when feasible, imaged intra-operatively by X-ray, and additional shavings were taken if needed based on clinical assessment. For each surgeon, historical re-excision rates were established based on a consecutive set of patients from a time period proximal to initiation of use of the device. From March 2013 to April 2014 the device was routinely used by 4 surgeons in 3 centers. In total, 165 cases lumpectomy cases were performed. Positive margins resulted in additional re-excision procedures in 9.7% (16/165) of the cases. The corresponding historical set from 2012 and 2013 consisted of 186 Lumpectomy cases, in which additional re-excision procedures were performed in 25.8% (48/186) of the cases. The reduction in the rate of re-excision procedures was significant 62% (P < 0.0001). Use of an intraoperative margin assessment device contributes to achieving clear margins and reducing re-excision procedures. As in some cases positive margins were found on shavings, future studies of interest may include an analysis of the effect of using the device on the shavings intra-operatively.

Histologic processing and reporting of cutaneous pigmented lesions: recommendations based on a survey of 94 dermatopathologists.

PubMed

Kolman, Olga; Hoang, Mai P; Piris, Adriano; Mihm, Martin C; Duncan, Lyn M

2010-10-01

Standard operating procedures for laboratory processing and reporting of margins of cutaneous pigmented lesions do not exist. We conducted a survey of 94 dermatopathologists to evaluate these practices. We sought to: (1) identify dominant practices among dermatopathologists; (2) determine the impact of the procedure, intent to excise, and histologic diagnosis on the process of margin evaluation; and (3) propose guidelines based on these findings. The survey consisted of 44 questions focused on the impact of procedure (punch, shave, or ellipse), intent (excision or biopsy), and histologic diagnosis (common nevus, congenital nevus, atypical nevus, melanoma) on processing and margin reporting. For ellipses, or specimens indicated as excisions, the majority practice (76%-98%) was to ink the specimens. Although more than 90% of observers report the margins on all melanomas and atypical nevi, fewer than 50% of respondents report margins on all nonatypical nevi. The study consists of a survey sample of dermatopathologists and does not represent the practices of those who did not respond to the survey. Based on the results of this survey we have arrived at the following recommendations: (1) ink all specimens that are ellipses or designated as excisions; (2) tips should be evaluated separately if the specimen is an ellipse; (3) obtain levels in cases with tumor in the tip but not at ink if the specimen is an ellipse or excision and the diagnosis is atypical nevus or melanoma; and (4) report margins on all atypical nevi and melanomas. Copyright © 2009 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.

Structure of a DNA glycosylase that unhooks interstrand cross-links

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mullins, Elwood A.; Warren, Garrett M.; Bradley, Noah P.

DNA glycosylases are important editing enzymes that protect genomic stability by excising chemically modified nucleobases that alter normal DNA metabolism. These enzymes have been known only to initiate base excision repair of small adducts by extrusion from the DNA helix. However, recent reports have described both vertebrate and microbial DNA glycosylases capable of unhooking highly toxic interstrand cross-links (ICLs) and bulky minor groove adducts normally recognized by Fanconi anemia and nucleotide excision repair machinery, although the mechanisms of these activities are unknown. Here we report the crystal structure of Streptomyces sahachiroi AlkZ (previously Orf1), a bacterial DNA glycosylase that protectsmore » its host by excising ICLs derived from azinomycin B (AZB), a potent antimicrobial and antitumor genotoxin. AlkZ adopts a unique fold in which three tandem winged helix-turn-helix motifs scaffold a positively charged concave surface perfectly shaped for duplex DNA. Through mutational analysis, we identified two glutamine residues and a β-hairpin within this putative DNA-binding cleft that are essential for catalytic activity. Additionally, we present a molecular docking model for how this active site can unhook either or both sides of an AZB ICL, providing a basis for understanding the mechanisms of base excision repair of ICLs. Given the prevalence of this protein fold in pathogenic bacteria, this work also lays the foundation for an emerging role of DNA repair in bacteria-host pathogenesis.« less

Residual Expression of the Reprogramming Factors Prevents Differentiation of iPSC Generated from Human Fibroblasts and Cord Blood CD34+ Progenitors

PubMed Central

Ramos-Mejía, Verónica; Montes, Rosa; Bueno, Clara; Ayllón, Verónica; Real, Pedro J.; Rodríguez, René; Menendez, Pablo

2012-01-01

Human induced pluripotent stem cells (hiPSC) have been generated from different tissues, with the age of the donor, tissue source and specific cell type influencing the reprogramming process. Reprogramming hematopoietic progenitors to hiPSC may provide a very useful cellular system for modelling blood diseases. We report the generation and complete characterization of hiPSCs from human neonatal fibroblasts and cord blood (CB)-derived CD34+ hematopoietic progenitors using a single polycistronic lentiviral vector containing an excisable cassette encoding the four reprogramming factors Oct4, Klf4, Sox2 and c-myc (OKSM). The ectopic expression of OKSM was fully silenced upon reprogramming in some hiPSC clones and was not reactivated upon differentiation, whereas other hiPSC clones failed to silence the transgene expression, independently of the cell type/tissue origin. When hiPSC were induced to differentiate towards hematopoietic and neural lineages those hiPSC which had silenced OKSM ectopic expression displayed good hematopoietic and early neuroectoderm differentiation potential. In contrast, those hiPSC which failed to switch off OKSM expression were unable to differentiate towards either lineage, suggesting that the residual expression of the reprogramming factors functions as a developmental brake impairing hiPSC differentiation. Successful adenovirus-based Cre-mediated excision of the provirus OKSM cassette in CB-derived CD34+ hiPSC with residual transgene expression resulted in transgene-free hiPSC clones with significantly improved differentiation capacity. Overall, our findings confirm that residual expression of reprogramming factors impairs hiPSC differentiation. PMID:22545141

The incidence and multiplicity rates of keratinocyte cancers in Australia.

PubMed

Pandeya, Nirmala; Olsen, Catherine M; Whiteman, David C

2017-10-16

To assess the incidence and multiplicity of keratinocyte cancers (basal cell carcinoma [BCC] and squamous cell carcinoma [SCC]) excised in Australia, and to examine variations by age, sex, state, and prior skin cancer history. Analysis of individual-level Medicare data for keratinocyte cancer treatments (identified by eight specific MBS item codes) during 2011-2014. Histological data from the QSkin prospective cohort study were analysed to estimate BCC and SCC incidence. A 10% systematic random sample of all people registered with Medicare during 1997-2014. People aged at least 20 years in 2011 who made at least one claim for any MBS medical service during 2011-2014 (1 704 193 individuals). Age-standardised incidence rates (ASRs) and standardised incidence ratios (SIRs). The person-based incidence of keratinocyte cancer excisions in Australia was 1531 per 100 000 person-years; incidence increased with age, and was higher for men than women (SIR, 1.43; 95% CI, 1.42-1.45). Lesion-based incidence was 3154 per 100 000 person-years. The estimated ASRs for BCC and SCC were 770 per 100 000 and 270 per 100 000 person-years respectively. During 2011-2014, 3.9% of Australians had one keratinocyte cancer excised, 2.7% had more than one excised; 74% of skin cancers were excised from patients who had two or more lesions removed. Multiplicity was strongly correlated with age; most male patients over 70 were treated for multiple lesions. Keratinocyte cancer incidence was eight times as high among people with a prior history of excisions as among those without. The incidence and multiplicity of keratinocyte cancer in Australia are very high, causing a large disease burden that has not previously been quantified.

POLYMORPHISMS IN THE DNA BASE EXCISION REPAIR GENES APEX1 AND XRCC1 AND LUNG CANCER RISK IN XUAN WEI, CHINA

EPA Science Inventory

The lung cancer mortality rate in Xuan Wei County is among the highest in China and has been attributed to exposure to indoor smoky coal emissions that contain very high levels of polycyclic aromatic hydrocarbons (PAHs). Nucleotide excision repair (NER) plays a key role in revers...

Cutaneous squamous cell carcinoma in an African pygmy hedgehog (Atelerix albiventris).

PubMed

Couture, Émilie L; Langlois, Isabelle; Santamaria-Bouvier, Ariane; Benoit-Biancamano, Marie-Odile

2015-12-01

A cutaneous mass was surgically excised in a 4-year-old African pygmy hedgehog (Atelerix albiventris). A squamous cell carcinoma was diagnosed based on histopathological examination and local recurrence following excision is strongly suspected. To the authors' knowledge, this is the first well-documented report of a cutaneous squamous cell carcinoma in this species.

Cutaneous squamous cell carcinoma in an African pygmy hedgehog (Atelerix albiventris)

PubMed Central

Couture, Émilie L.; Langlois, Isabelle; Santamaria-Bouvier, Ariane; Benoit-Biancamano, Marie-Odile

2015-01-01

A cutaneous mass was surgically excised in a 4-year-old African pygmy hedgehog (Atelerix albiventris). A squamous cell carcinoma was diagnosed based on histopathological examination and local recurrence following excision is strongly suspected. To the authors’ knowledge, this is the first well-documented report of a cutaneous squamous cell carcinoma in this species. PMID:26663924

Alpha-dispersion in human tissue

NASA Astrophysics Data System (ADS)

Grimnes, Sverre; Martinsen, Ørjan G.

2010-04-01

Beta dispersion is found in living tissue in the kilohertz - megahertz range and is caused by the cellular structure of biological materials with low frequency properties caused by cell membranes. Alpha dispersion is found in the hertz range and the causes are not so well known. Alpha dispersions are the first to disappear when tissue dies. Tissue data have often been based upon excised specimen from animals and are therefore not necessarily representative for human tissue alpha dispersions. Here we present data obtained with non-invasive skin surface electrodes for different segments of the living human body. We found alpha dispersions in all cases; the ankle-wrist results had the smallest. Large alpha dispersions were found where the distance between the electrodes and muscle masses was small, e.g. on the calf. Further studies on electrode technique and reciprocity, electrode positioning, statistical variations, gender, age and bodily constitutions are necessary in order to reveal more about the alpha dispersion, its appearance and disappearance.

Comparative analysis of different laser systems to study cellular responses to DNA damage in mammalian cells

PubMed Central

Kong, Xiangduo; Mohanty, Samarendra K.; Stephens, Jared; Heale, Jason T.; Gomez-Godinez, Veronica; Shi, Linda Z.; Kim, Jong-Soo; Yokomori, Kyoko; Berns, Michael W.

2009-01-01

Proper recognition and repair of DNA damage is critical for the cell to protect its genomic integrity. Laser microirradiation ranging in wavelength from ultraviolet A (UVA) to near-infrared (NIR) can be used to induce damage in a defined region in the cell nucleus, representing an innovative technology to effectively analyze the in vivo DNA double-strand break (DSB) damage recognition process in mammalian cells. However, the damage-inducing characteristics of the different laser systems have not been fully investigated. Here we compare the nanosecond nitrogen 337 nm UVA laser with and without bromodeoxyuridine (BrdU), the nanosecond and picosecond 532 nm green second-harmonic Nd:YAG, and the femtosecond NIR 800 nm Ti:sapphire laser with regard to the type(s) of damage and corresponding cellular responses. Crosslinking damage (without significant nucleotide excision repair factor recruitment) and single-strand breaks (with corresponding repair factor recruitment) were common among all three wavelengths. Interestingly, UVA without BrdU uniquely produced base damage and aberrant DSB responses. Furthermore, the total energy required for the threshold H2AX phosphorylation induction was found to vary between the individual laser systems. The results indicate the involvement of different damage mechanisms dictated by wavelength and pulse duration. The advantages and disadvantages of each system are discussed. PMID:19357094

DNA excision repair in cell extracts from human cell lines exhibiting hypersensitivity to DNA-damaging agents

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hansson, J.; Keyse, S.M.; Lindahl, T.

Whole cell extracts from human lymphoid cell lines can perform in vitro DNA repair synthesis in plasmids damaged by agents including UV or cis-diamminedichloroplatinum(II) (cis-DDP). Extracts from xeroderma pigmentosum (XP) cells are defective in repair synthesis. We have now studied in vitro DNA repair synthesis using extracts from lymphoblastoid cell lines representing four human hereditary syndromes with increased sensitivity to DNA-damaging agents. Extracts of cell lines from individuals with the sunlight-sensitive disorders dysplastic nevus syndrome or Cockayne's syndrome (complementation groups A and B) showed normal DNA repair synthesis in plasmids with UV photoproducts. This is consistent with in vivo measurementsmore » of the overall DNA repair capacity in such cell lines. A number of extracts were prepared from two cell lines representing the variant form of XP (XP-V). Half of the extracts prepared showed normal levels of in vitro DNA repair synthesis in plasmids containing UV lesions, but the remainder of the extracts from the same cell lines showed deficient repair synthesis, suggesting the possibility of an unusually labile excision repair protein in XP-V. Fanconi's anemia (FA) cells show cellular hypersensitivity to cross-linking agents including cis-DDP. Extracts from cell lines belonging to two different complementation groups of FA showed normal DNA repair synthesis in plasmids containing cis-DDP or UV adducts. Thus, there does not appear to be an overall excision repair defect in FA, but the data do not exclude a defect in the repair of interstrand DNA cross-links.« less

Influence of Lactobacillus acidophilus and Lactobacillus plantarum on wound healing in male Wistar rats - an experimental study.

PubMed

Gudadappanavar, Anupama M; Hombal, Prashant R; Timashetti, Somling S; Javali, S B

2017-01-01

Probiotics have been documented with various pleotropic effects other than improving general gut health, but the potential benefits of strain-specific Lactobacillus on wound healing are unknown. Hence, the objective of the study is to evaluate and compare the wound healing property of Lactobacillus acidophilus and Lactobacillus plantarum on various wound models in male Wistar rats. Excision wound, resutured incision wound, and dead space wounds were inflicted under light thiopentone anesthesia in male Wistar rats ( n = 6, in each group). The rats received one of the Lactobacillus orally as per their weight for a period of 10 days in resutured incision (assessed by wound breaking strength) and dead space wounds (granuloma dry weight, histopathology of granulation tissue, and biochemical hydroxyproline estimation), whereas in excision wounds, treatment was monitored by planimetry. Data were expressed as mean ± standard error of mean and analyzed by ANOVA followed by Tukey's multiple post hoc test. P < 0.05 was considered as statistically significant. L. acidophilus showed a significant difference ( P < 0.05) in all the three models, namely, enhanced wound contraction and decreased days for complete epithelization in excision wound; increased breaking strength in resutured incision wound; increased granuloma dry weight and cellular infiltration in granulation tissue with marked increase in collagen content indicating wound healing. The study suggests that the wound healing activity of L. acidophilus if could be extrapolated to clinical situations may decrease dosage and duration of treatment and can be a potential adjuvant to reduce hospitalization with efficient recovery after injury and sustained good health.

Wound-healing potential of the fruit extract of Phaleria macrocarpa.

PubMed

Abood, Walaa Najm; Al-Henhena, Nawal Ahmed; Najim Abood, Ammar; Al-Obaidi, Mazen M Jamil; Ismail, Salmah; Abdulla, Mahmood Ameen; Al Bartan, Rami

2015-05-12

The wound-healing potential of Phaleria macrocarpa was evaluated by monitoring the levels of inflammatory mediators, collagen, and antioxidant enzymes. Experimentally, two-centimeter-wide full-thickness-deep skin excision wounds were created on the posterior neck area of the rats. The wounds were topically treated with gum acacia as a vehicle in the control group, intrasite gel in the reference group, and 100 and 200 mg/mL P. macrocarpa ‎fruit extract in the treatment group. Granulation tissues were excised on the 15th day and were further processed for histological and biochemical analyzes. Wound healing was evaluated by measuring the contractions and protein contents of the wounds. Cellular redistribution and collagen deposition were assessed morphologically using Masson's trichrome stain. Superoxide dismutase (SOD) and catalase (CAT) activities, along with malondialdehyde (MDA) level were determined in skin tissue homogenates of the dermal wounds. Serum levels of transforming growth factor beta 1 (TGF-β1) and tumor necrosis factor alpha (TNF-α) were evaluated in all the animals. A significant decrease in wound area was caused by a significant increase in TGF-β1 level in the treated groups. Decrease in TNF-α level and increase in the collagen formation were also observed in the treated groups. Topical treatment with P. macrocarpa fruit extract increased the SOD and CAT activities in the healing wounds, thereby significantly increasing MDA level. The topical treatment with P. macrocarpa fruit extract showed significant healing effect on excision wounds and demonstrated an important role in the inflammation process by increasing antioxidant enzyme activities, thereby accelerating the wound healing process and reducing tissue injury.

Regulation of cellular marker modulated upon irradiation of low power laser light in burn injured mice

NASA Astrophysics Data System (ADS)

Rathnakar, Bharath; Prabhu, Vijendra; Rao, Bola Sadashiva Satish; Chandra, Subhash; Rai, Sharada; Mahato, Krishna Kishore

2016-12-01

The present study intends to understand the importance of cellular marker in tissue regeneration regulated upon irradiation of low power laser light in burn inflicted mice. Under anesthetic conditions, the thermal injury was induced on Swiss albino mice of either sex. Following injury, the animals were randomly divided into three groups; i. e., un-illuminated control, the group treated with 5% Povidone iodine (reference standard) and single exposure of 3 J/cm2 (830 nm). Burn tissue samples from each group were excised at day 6 post burn injury upon euthanization and used for histological and immunohistochemical analysis. Haematoxylin and Eosin (H and E) staining was performed on the selected sections to asses proliferation and angiogenesis at day 6 post-injury. For immunohistochemical analysis, tissue sections from all the three treatment groups on day 6 were stained using specific antibody against Proliferating cell nuclear antigen (PCNA). The results of the histological and immunohistochemical analysis showed improved tissue restoration in animals treated with optimal laser influence as compared to un-illuminated controls. The findings of present study clearly demonstrated the beneficial effects of 830 nm laser in burn wound healing and its influence in regulating the cellular marker.

Clinical confocal microlaparoscope for real-time in vivo optical biopsies

NASA Astrophysics Data System (ADS)

Tanbakuchi, Anthony A.; Rouse, Andrew R.; Udovich, Joshua A.; Hatch, Kenneth D.; Gmitro, Arthur F.

2009-07-01

Successful treatment of cancer is highly dependent on the stage at which it is diagnosed. Early diagnosis, when the disease is still localized at its origin, results in very high cure rates-even for cancers that typically have poor prognosis. Biopsies are often used for diagnosis of disease. However, because biopsies are destructive, only a limited number can be taken. This leads to reduced sensitivity for detection due to sampling error. A real-time fluorescence confocal microlaparoscope has been developed that provides instant in vivo cellular images, comparable to those provided by histology, through a nondestructive procedure. The device includes an integrated contrast agent delivery mechanism and a computerized depth scan system. The instrument uses a fiber bundle to relay the image plane of a slit-scan confocal microlaparoscope into tissue. It has a 3-μm lateral resolution and a 25-μm axial resolution. Initial in vivo clinical testing using the device to image human ovaries has been done in 21 patients. Results indicate that the device can successfully image organs in vivo without complications. Results with excised tissue demonstrate that the instrument can resolve sufficient cellular detail to visualize the cellular changes associated with the onset of cancer.

Comparison of electric and growth responses to excision in cucumber and pea seedlings. II. Long-distance effects are caused by the release of xylem pressure

NASA Technical Reports Server (NTRS)

Stahlberg, R.; Cosgrove, D. J.

1995-01-01

Excision of a growing stem causes local wound responses, such as membrane depolarization and growth inhibition, as well as effects at larger distances from the cut. In this study, cucumber hypocotyls were excised 100 mm below the hook, so that the growing region was beyond the reach of the wound-induced depolarization (up to 40 mm). Even at such a distance, the cut still caused a considerable and rapid drop in the hypocotyl growth rate. This growth response is not a direct wound response because it does not result from the cut-induced depolarization and because it can be simulated by root pressure manipulation (using a pressure chamber). The results indicate that the growth response resulted from the rapid release of the xylem pressure upon excision. To test this conclusion we measured the xylem pressure by connecting a pressure probe to the cut surface of the stem. Xylem pressure (Px) was found to be +10 to +40 kPa in cucumber hypocotyls and -5 to -10 kPa or lower in pea epicotyls. Excision of the cucumber hypocotyl base led to a rapid drop in Px to negative values, whereas excision in pea led to a rapid rise in Px to ambient (zero) pressure. These fast and opposite Px changes parallel the excision-induced changes in growth rate (GR): a decrease in cucumber and a rise in pea. The sign of the endogenous xylem pressure also determined whether excision induced a propagating depolarization in the form of a slow wave potential (SWP). Under normal circumstances pea seedlings generated an SWP upon excision whereas cucumber seedlings failed to do so. When the Px in cucumber hypocotyls was experimentally inverted to negative values by incubating the cumber roots in solutions of NaCN or n-ethylmaleimide, excision caused a propagating depolarization (SWP). The experiment shows that only hydraulic signals in the form of positive Px steps are converted into propagating electric SWP signals. These propagating depolarizations might be causally linked to systemic 'wound' responses, which occur independently of the short-distance or direct wound responses.

Magnetic resonance imaging findings of cellular angiofibroma of the tunica vaginalis of the testis: a case report.

PubMed

Ntorkou, Alexandra A; Tsili, Athina C; Giannakis, Dimitrios; Batistatou, Anna; Stavrou, Sotirios; Sofikitis, Nikolaos; Argyropoulou, Maria I

2016-03-31

Cellular angiofibroma represents a rare mesenchymal tumor typically involving the inguinoscrotal area in middle-aged men. Although the origin of this benign tumor is unknown, it is histologically classified as an angiomyxoid tumor. Cellular angiofibroma is characterized by a diversity of pathological and imaging features. An accurate preoperative diagnosis is challenging. Magnetic resonance imaging examination of the scrotum has been reported as a valuable adjunct modality in the investigation of scrotal pathology. The technique by providing both structural and functional information is useful in the differentiation between extratesticular and intratesticular diseases and in the preoperative characterization of the histologic nature of various scrotal lesions. There are few reports in the English literature addressing the magnetic resonance imaging findings of cellular angiofibroma of the scrotum and no reports on functional magnetic resonance imaging data. Here we present the first case of a cellular angiofibroma arising from the tunica vaginalis of the testis and we discuss the value of a multiparametric magnetic resonance protocol, including diffusion-weighted imaging, magnetization transfer imaging and dynamic contrast-enhanced magnetic resonance imaging in the preoperative diagnosis of this rare neoplasm. A 47-year Greek man presented with a painless left scrotal swelling, which had gradually enlarged during the last 6 months. Magnetic resonance imaging of his scrotum displayed a left paratesticular mass, in close proximity to the tunica vaginalis, with heterogeneous high signal intensity on T2-weighted images and no areas of restricted diffusion. The tumor was hypointense on magnetization transfer images, suggestive for the presence of macromolecules. On dynamic contrast-enhanced magnetic resonance imaging the mass showed intense heterogeneous enhancement with a type II curve. Magnetic resonance imaging findings were strongly suggestive of a benign paratesticular tumor, which was confirmed on pathology following lesion excision. Magnetic resonance imaging of the scrotum by combining conventional and functional magnetic resonance data provides useful diagnostic information in the preoperative characterization of scrotal masses. A possible diagnosis of a benign paratesticular tumor based on magnetic resonance imaging features may improve patient care and decrease the number of unnecessary radical surgical explorations.

Nuclear depletion of apurinic/apyrimidinic endonuclease 1 (Ape1/Ref-1) is an indicator of energy disruption in neurons.

PubMed

Singh, Shilpee; Englander, Ella W

2012-11-01

Apurinic/apyrimidinic endonuclease 1 (Ape1/Ref-1) is a multifunctional protein critical for cellular survival. Its involvement in adaptive survival responses includes key roles in redox sensing, transcriptional regulation, and repair of DNA damage via the base excision repair (BER) pathway. Ape1 is abundant in most cell types and central in integrating the first BER step catalyzed by different DNA glycosylases. BER is the main process for removal of oxidative DNA lesions in postmitotic brain cells, and after ischemic brain injury preservation of Ape1 coincides with neuronal survival, while its loss has been associated with neuronal death. Here, we report that in cultured primary neurons, diminution of cellular ATP by either oligomycin or H(2)O(2) is accompanied by depletion of nuclear Ape1, while other BER proteins are unaffected and retain their nuclear localization under these conditions. Importantly, while H(2)O(2) induces γH2AX phosphorylation, indicative of chromatin rearrangements in response to DNA damage, oligomycin does not. Furthermore, despite comparable diminution of ATP content, H(2)O(2) and oligomycin differentially affect critical parameters of mitochondrial respiration that ultimately determine cellular ATP content. Taken together, our findings demonstrate that in neurons, nuclear compartmentalization of Ape1 depends on ATP and loss of nuclear Ape1 reflects disruption of neuronal energy homeostasis. Energy crisis is a hallmark of stroke and other ischemic/hypoxic brain injuries. In vivo studies have shown that Ape1 deficit precedes neuronal loss in injured brain regions. Thus, our findings bring to light the possibility that energy failure-induced Ape1 depletion triggers neuronal death in ischemic brain injuries. Copyright © 2012 Elsevier Inc. All rights reserved.

Early use of negative pressure therapy in combination with silver dressings in a difficult breast abscess.

PubMed

Richards, Alastair J; Hagelstein, Sue M; Patel, Girish K; Ivins, Nicola M; Sweetland, Helen M; Harding, Keith G

2011-12-01

Combining silver-based dressings with negative pressure therapy after radical excision of chronically infected breast disease is a novel application of two technologies. One patient with complex, chronic, infected breast disease underwent radical excision of the affected area and was treated early with a combination of silver-based dressings and topical negative pressure therapy. The wound was then assessed sequentially using clinical measurements of wound area and depth, pain severity scores and level of exudation. It is possible to combine accepted techniques with modern dressing technologies that result in a positive outcome. In this case, the combination of a silver-based dressing with negative pressure therapy following radical excision proved safe and was well tolerated by the patient. Full epithelisation of the wound was achieved and there was no recurrence of the infection for the duration of the treatment. © 2011 The Authors. © 2011 Blackwell Publishing Ltd and Medicalhelplines.com Inc.

Perforator Flaps after Excision of Large Epidermal Cysts in the Buttocks

PubMed Central

Kim, Sang Wha; Yang, Seong Hyeok; Kim, Jeong Tae

2014-01-01

Background Epidermal cysts are commonly occurring masses usually less than 5 cm in diameter, but in predisposed patients, epidermal cysts can grow relatively large due to chronic infection. Methods From June 2002 to July 2010, 17 patients received 19 regional perforator-based island flaps to cover defects due to the excision of large epidermal cysts (diameter >5 cm) in the buttocks. Eight patients had diabetes, and seven had rheumatoid arthritis. The pedicles were not fully isolated to prevent spasms or twisting. Results All the flaps survived completely, except for one case with partial necrosis of the flap, which necessitated another perforator-based island flap for coverage. There were two cases of wound dehiscence, which were re-closed after meticulous debridement. There were no recurrences of the masses during follow-up periods of 8.1 months (range, 6-12 months). Conclusions In patients with large epidermal cysts and underlying medical disorders, regional perforator-based island flaps can be the solution to coverage of the defects after excision. PMID:24665422

Monitoring of the spatial and temporal dynamics of BER/SSBR pathway proteins, including MYH, UNG2, MPG, NTH1 and NEIL1-3, during DNA replication.

PubMed

Bj Rås, Karine Ø; Sousa, Mirta M L; Sharma, Animesh; Fonseca, Davi M; S Gaard, Caroline K; Bj Rås, Magnar; Otterlei, Marit

2017-08-21

Base lesions in DNA can stall the replication machinery or induce mutations if bypassed. Consequently, lesions must be repaired before replication or in a post-replicative process to maintain genomic stability. Base excision repair (BER) is the main pathway for repair of base lesions and is known to be associated with DNA replication, but how BER is organized during replication is unclear. Here we coupled the iPOND (isolation of proteins on nascent DNA) technique with targeted mass-spectrometry analysis, which enabled us to detect all proteins required for BER on nascent DNA and to monitor their spatiotemporal orchestration at replication forks. We demonstrate that XRCC1 and other BER/single-strand break repair (SSBR) proteins are enriched in replisomes in unstressed cells, supporting a cellular capacity of post-replicative BER/SSBR. Importantly, we identify for the first time the DNA glycosylases MYH, UNG2, MPG, NTH1, NEIL1, 2 and 3 on nascent DNA. Our findings suggest that a broad spectrum of DNA base lesions are recognized and repaired by BER in a post-replicative process. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

Chloroethyinitrosourea-derived ethano cytosine and adenine adducts are substrates for escherichia coli glycosylases excising analogous etheno adducts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guliaev, Anton B.; Singer, B.; Hang, Bo

2004-05-05

Exocyclic ethano DNA adducts are saturated etheno ring derivatives formed mainly by therapeutic chloroethylnitrosoureas (CNUs), which are also mutagenic and carcinogenic. In this work, we report that two of the ethano adducts, 3,N{sup 4}-ethanocytosine (EC) and 1,N{sup 6}-ethanoadenine (EA), are novel substrates for the Escherichia coli mismatch-specific uracil-DNA glycosylase (Mug) and 3-methyladenine DNA glycosylase II (AlkA), respectively. It has been shown previously that Mug excises 3,N{sup 4}-ethenocytosine ({var_epsilon}C) and AlkA releases 1,N{sup 6}-ethenoadenine ({var_epsilon}A). Using synthetic oligonucleotides containing a single ethano or etheno adduct, we found that both glycosylases had a {approx}20-fold lower excision activity toward EC or EA thanmore » that toward their structurally analogous {var_epsilon}C or {var_epsilon}A adduct. Both enzymes were capable of excising the ethano base paired with any of the four natural bases, but with varying efficiencies. The Mug activity toward EC could be stimulated by E. coli endonuclease IV and, more efficiently, by exonuclease III. Molecular dynamics (MD) simulations showed similar structural features of the etheno and ethano derivatives when present in DNA duplexes. However, also as shown by MD, the stacking interaction between the EC base and Phe 30 in the Mug active site is reduced as compared to the {var_epsilon}C base, which could account for the lower EC activity observed in this study.« less

Flat epithelial atypia on core needle biopsy, must we surgically excise?

PubMed

Acott, A A; Mancino, A T

2016-12-01

Breast flat epithelial atypia (FEA) often coexists with more aggressive pathology and excision is currently recommended when diagnosed by core needle biopsy (CNB). Recent studies suggest isolated FEA has a low association with carcinoma and may warrant close surveillance. A radiology database containing 2189 breast CNB was reviewed for isolated FEA or FEA in combination with atypical pathology. 79 patients had FEA. There were 48/79 with isolated FEA and 31/79 concomitant FEA with ADH, ALH, or LCIS. 46 subsequent excisional biopsies of isolated FEA resulted: benign 38/46, ADH 5/46, LCIS 2/46, DCIS 1/46. Concomitant FEA + ADH/ALH/LCIS group resulted: benign 26/31, DCIS 3/31, DCIS and LCIS 1/31, tubular carcinoma 1/31. DCIS/invasive cancer on excision in the FEA + ADH group is 5/31 versus 1/46 for isolated FEA (p 0.0489). Findings support literature suggesting isolated FEA has a low association with carcinoma. These patients may not require surgical excision, but instead have close surveillance. Based on the higher cancer incidence in FEA combined with ADH, ALH, LCIS, or residual microcalcifications, we still recommend surgical excision. Breast flat epithelial atypia (FEA) often coexists with more aggressive pathology and surgical excision is currently recommended when diagnosed by core needle biopsy. Recent studies have suggested isolated FEA has a low association with carcinoma and these patients may warrant close surveillance. Isolated FEA has a low association with carcinoma in our series. These patients may not require surgical excision, but instead have close surveillance. Published by Elsevier Inc.

Awake craniotomy for excision of arteriovenous malformations? A qualitative comparison study with stereotactic radiosurgery.

PubMed

Chan, David Yuen Chung; Chan, Danny Tat Ming; Zhu, Cannon Xian Lun; Kan, Patricia Kwok Yee; Ng, Amelia Yikjin; Hsieh, Yi-Pin Sonia; Abrigo, Jill; Poon, Wai Sang; Wong, George Kwok Chu

2018-05-01

Treatment of arteriovenous malformations (AVM) located at the eloquent area has been a challenge. Awake brain mapping allows identification of a non-eloquent gyrus for intervention and can potentially facilitate resection with preservation of functions. An alternative treatment option is stereotactic radiosurgery (SRS). The objective of this study was to perform a qualitative comparison of the treatment outcome of awake AVM excision versus SRS. We conducted a 13-year retrospective review of AVM excision under awake craniotomy performed at Prince of Wales Hospital, Hong Kong, from 2003 to 2016. Patients' presentation, Spetzler-Martin (SM) grading, rate of obliteration and complication were reviewed and analyzed with the modified radiosurgery-based AVM score (RS score). Six patients had excision of AVM under awake mapping during this period of time. Two were SM Grade II and four were SM Grade III. Five located at the peri-rolandic region while one at the temporal language area. None had failed mapping. Five out of six achieved complete obliteration (83.3%). Qualitative comparative analysis had revealed better treatment outcome with awake AVM excision as compared to SRS with the obliteration rate of 100% versus 96% for RS score ≤1.00, 100% versus 78% for RS score 1.01-1.50, and 66% versus 50% for RS score >2.00 respectively. In conclusion, awake mapping and excision of AVMs at the eloquent area is feasible. Qualitative comparative analysis had revealed higher obliteration rate with awake AVM excision as compared to SRS. Copyright © 2018 Elsevier Ltd. All rights reserved.

Generation of DNA single-strand displacement by compromised nucleotide excision repair

PubMed Central

Godon, Camille; Mourgues, Sophie; Nonnekens, Julie; Mourcet, Amandine; Coin, Fréderic; Vermeulen, Wim; Mari, Pierre-Olivier; Giglia-Mari, Giuseppina

2012-01-01

Nucleotide excision repair (NER) is a precisely coordinated process essential to avoid DNA damage-induced cellular malfunction and mutagenesis. Here, we investigate the mechanistic details and effects of the NER machinery when it is compromised by a pathologically significant mutation in a subunit of the repair/transcription factor TFIIH, namely XPD. In contrast to previous studies, we find that no single- or double-strand DNA breaks are produced at early time points after UV irradiation of cells bearing a specific XPD mutation, despite the presence of a clear histone H2AX phosphorylation (γH2AX) signal in the UV-exposed areas. We show that the observed γH2AX signal can be explained by the presence of longer single-strand gaps possibly generated by strand displacement. Our in vivo measurements also indicate a strongly reduced TFIIH-XPG binding that could promote single-strand displacement at the site of UV lesions. This finding not only highlights the crucial role of XPG's interactions with TFIIH for proper NER, but also sheds new light on how a faulty DNA repair process can induce extreme genomic instability in human patients. PMID:22863773

Oxidative Damage to RPA Limits the Nucleotide Excision Repair Capacity of Human Cells.

PubMed

Guven, Melisa; Brem, Reto; Macpherson, Peter; Peacock, Matthew; Karran, Peter

2015-11-01

Nucleotide excision repair (NER) protects against sunlight-induced skin cancer. Defective NER is associated with photosensitivity and a high skin cancer incidence. Some clinical treatments that cause photosensitivity can also increase skin cancer risk. Among these, the immunosuppressant azathioprine and the fluoroquinolone antibiotics ciprofloxacin and ofloxacin interact with UVA radiation to generate reactive oxygen species that diminish NER capacity by causing protein damage. The replication protein A (RPA) DNA-binding protein has a pivotal role in DNA metabolism and is an essential component of NER. The relationship between protein oxidation and NER inhibition was investigated in cultured human cells expressing different levels of RPA. We show here that RPA is limiting for NER and that oxidative damage to RPA compromises NER capability. Our findings reveal that cellular RPA is surprisingly vulnerable to oxidation, and we identify oxidized forms of RPA that are associated with impaired NER. The vulnerability of NER to inhibition by oxidation provides a connection between cutaneous photosensitivity, protein damage, and increased skin cancer risk. Our findings emphasize that damage to DNA repair proteins, as well as to DNA itself, is likely to be an important contributor to skin cancer risk.

Mitotic regulator Nlp interacts with XPA/ERCC1 complexes and regulates nucleotide excision repair (NER) in response to UV radiation.

PubMed

Ma, Xiao-Juan; Shang, Li; Zhang, Wei-Min; Wang, Ming-Rong; Zhan, Qi-Min

2016-04-10

Cellular response to DNA damage, including ionizing radiation (IR) and UV radiation, is critical for the maintenance of genomic fidelity. Defects of DNA repair often result in genomic instability and malignant cell transformation. Centrosomal protein Nlp (ninein-like protein) has been characterized as an important cell cycle regulator that is required for proper mitotic progression. In this study, we demonstrate that Nlp is able to improve nucleotide excision repair (NER) activity and protects cells against UV radiation. Upon exposure of cells to UVC, Nlp is translocated into the nucleus. The C-terminus (1030-1382) of Nlp is necessary and sufficient for its nuclear import. Upon UVC radiation, Nlp interacts with XPA and ERCC1, and enhances their association. Interestingly, down-regulated expression of Nlp is found to be associated with human skin cancers, indicating that dysregulated Nlp might be related to the development of human skin cancers. Taken together, this study identifies mitotic protein Nlp as a new and important member of NER pathway and thus provides novel insights into understanding of regulatory machinery involved in NER. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

The management of non-tuberculous cervicofacial lymphadenitis in children: A systematic review and meta-analysis.

PubMed

Zimmermann, Petra; Tebruegge, Marc; Curtis, Nigel; Ritz, Nicole

2015-07-01

Cervicofacial lymphadenitis is the most common manifestation of infection with non-tuberculous mycobacteria (NTM) in immunocompetent children. Although complete excision is considered standard management, the optimal treatment remains controversial. This study reviews the evidence for different management options for NTM lymphadenitis. A systematic literature review and meta-analysis were performed including 1951 children from sixty publications. Generalised linear mixed model regressions were used to compare treatment modalities. The adjusted mean cure rate was 98% (95% CI 97.0-99.5%) for complete excision, 73.1% (95% CI 49.6-88.3%) for anti-mycobacterial antibiotics, and 70.4% (95% CI 49.6-88.3%) for 'no intervention'. Compared to 'no intervention', only complete excision was significantly associated with cure (OR 33.1; 95% CI 10.8-102.9; p < 0.001). Complete excision was associated with a 10% risk of facial nerve palsy (2% permanent). 'No intervention' was associated with delayed resolution. Complete excision is associated with the highest cure rate in NTM cervicofacial lymphadenitis, but also had the highest risk of facial nerve palsy. In the absence of large, well-designed RCTs, the choice between surgical excision, anti-mycobacterial antibiotics and 'no intervention' should be based on the location and extent of the disease, and acceptability of prolonged time to resolution. Copyright © 2015 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

Optical metabolic imaging of live tissue cultures

NASA Astrophysics Data System (ADS)

Walsh, Alex J.; Cook, Rebecca S.; Arteaga, Carlos L.; Skala, Melissa C.

2013-02-01

The fluorescence properties, both intensity and fluorescence lifetime, of NADH and FAD, two coenzymes of metabolism, are sensitive, high resolution measures of cellular metabolism. However, often in vivo measurements of tissue are not feasible. In this study, we investigate the stability over time of two-photon auto-fluorescence imaging of NADH and FAD in live-cultured tissues. Our results demonstrate that cultured tissues remain viable for at least several days post excision. Furthermore, the optical redox ratio, NADH fluorescence lifetime, and FAD fluorescence lifetime do not significantly change in the cultured tissues over time. With these findings, we demonstrate the potential of sustained tissue culture techniques for optical metabolic imaging.

Optical coherence elastography for cellular-scale stiffness imaging of mouse aorta

NASA Astrophysics Data System (ADS)

Wijesinghe, Philip; Johansen, Niloufer J.; Curatolo, Andrea; Sampson, David D.; Ganss, Ruth; Kennedy, Brendan F.

2017-04-01

We have developed a high-resolution optical coherence elastography system capable of estimating Young's modulus in tissue volumes with an isotropic resolution of 15 μm over a 1 mm lateral field of view and a 100 μm axial depth of field. We demonstrate our technique on healthy and hypertensive, freshly excised and intact mouse aortas. Our technique has the capacity to delineate the individual mechanics of elastic lamellae and vascular smooth muscle. Further, we observe global and regional vascular stiffening in hypertensive aortas, and note the presence of local micro-mechanical signatures, characteristic of fibrous and lipid-rich regions.

EVIDENCE FOR BASE EXCISION REPAIR PROCESSING OF DNA INTERSTRAND CROSSLINKS

PubMed Central

Kothandapani, Anbarasi; Patrick, Steve M

2013-01-01

Many bifunctional alkylating agents and anticancer drugs exert their cytotoxicity by producing cross links between the two complementary strands of DNA, termed interstrand crosslinks (ICLs). This blocks the strand separating processes during DNA replication and transcription, which can lead to cell cycle arrest and apoptosis. Cells use multiple DNA repair systems to eliminate the ICLs. Concerted action of repair proteins involved in Nucleotide Excision Repair and Homologous Recombination pathways are suggested to play a key role in the ICL repair. However, recent studies indicate a possible role for Base Excision Repair (BER) in mediating the cytotoxicity of ICL inducing agents in mammalian cells. Elucidating the mechanism of BER mediated modulation of ICL repair would help in understanding the recognition and removal of ICLs and aid in the development of potential therapeutic agents. In this review, the influence of BER proteins on ICL DNA repair and the possible mechanisms of action are discussed. PMID:23219605

Surgical risk factors for recurrence of inverted papilloma.

PubMed

Healy, David Y; Chhabra, Nipun; Metson, Ralph; Holbrook, Eric H; Gray, Stacey T

2016-04-01

To identify variations in surgical technique that impact the recurrence of inverted papilloma following endoscopic excision. Retrospective cohort. Data from 127 consecutive patients who underwent endoscopic excision of inverted papilloma and oncocytic papilloma at a tertiary care medical center from 1998 to 2011 were reviewed. Patient demographics, comorbidities, tumor stage, and intraoperative details, including tumor location and management of the base, were evaluated to identify factors associated with tumor recurrence. Recurrence of papilloma occurred in 16 patients (12.6%). Mean time to recurrence was 31.0 months (range, 5.2-110.0 months). Mucosal stripping alone was associated with a recurrence rate of 52.2% (12/23 patients), compared to 4.9% (3/61 patients) when the tumor base was drilled, 4.7% (1/21 patients) when it was cauterized, and 0.0% (0/22 patients) when it was completely excised (P = .001). Increased recurrence rate was associated with tumors located in the maxillary sinus (P = .03), as well as the performance of endoscopic medial maxillectomy (P = .001) and external frontal approaches (P = .02). Drilling, cauterizing, or completely excising the bone underlying the tumor base during endoscopic resection reduces the recurrence rate of inverted and oncocytic papilloma, when compared to mucosal stripping alone. Surgeons who perform endoscopic resection of these tumors should consider utilization of these techniques when possible. 4. © 2015 The American Laryngological, Rhinological and Otological Society, Inc.

Both base excision repair and nucleotide excision repair in humans are influenced by nutritional factors.

PubMed

Brevik, Asgeir; Karlsen, Anette; Azqueta, Amaya; Tirado, Anna Estaban; Blomhoff, Rune; Collins, Andrew

2011-01-01

Lack of reliable assays for DNA repair has largely prevented measurements of DNA repair from being included in human biomonitoring studies. Using newly developed modifications of the comet assay we tested whether a fruit- and antioxidant-rich plant-based intervention could affect base excision repair (BER) and nucleotide excision repair (NER) in a group of 102 male volunteers. BER and NER repair capacities were measured in lymphocytes before and after a dietary intervention lasting 8 weeks. The study had one control group, one group consuming three kiwifruits per day and one group consuming a variety of antioxidant-rich fruits and plant products in addition to their normal diet. DNA strand breaks were reduced following consumption of both kiwifruits (13%, p = 0.05) and antioxidant-rich plant products (20%, p = 0.02). Increased BER (55%, p = 0.01) and reduced NER (-39%, p < 0.01) were observed in the group consuming a wide variety of plant products. Reduced NER was also observed in the kiwifruit group (-38%, p = 0.05), but BER was not affected in this group. Here we have demonstrated that DNA repair is affected by diet and that modified versions of the comet assay can be used to assess activity of different DNA repair pathways in human biomonitoring studies. Copyright © 2010 John Wiley & Sons, Ltd.

Whole-body tissue stabilization and selective extractions via tissue-hydrogel hybrids for high-resolution intact circuit mapping and phenotyping.

PubMed

Treweek, Jennifer B; Chan, Ken Y; Flytzanis, Nicholas C; Yang, Bin; Deverman, Benjamin E; Greenbaum, Alon; Lignell, Antti; Xiao, Cheng; Cai, Long; Ladinsky, Mark S; Bjorkman, Pamela J; Fowlkes, Charless C; Gradinaru, Viviana

2015-11-01

To facilitate fine-scale phenotyping of whole specimens, we describe here a set of tissue fixation-embedding, detergent-clearing and staining protocols that can be used to transform excised organs and whole organisms into optically transparent samples within 1-2 weeks without compromising their cellular architecture or endogenous fluorescence. PACT (passive CLARITY technique) and PARS (perfusion-assisted agent release in situ) use tissue-hydrogel hybrids to stabilize tissue biomolecules during selective lipid extraction, resulting in enhanced clearing efficiency and sample integrity. Furthermore, the macromolecule permeability of PACT- and PARS-processed tissue hybrids supports the diffusion of immunolabels throughout intact tissue, whereas RIMS (refractive index matching solution) grants high-resolution imaging at depth by further reducing light scattering in cleared and uncleared samples alike. These methods are adaptable to difficult-to-image tissues, such as bone (PACT-deCAL), and to magnified single-cell visualization (ePACT). Together, these protocols and solutions enable phenotyping of subcellular components and tracing cellular connectivity in intact biological networks.

[Evaluation of the results of surgical treatment of granuloma teleangiectodes].

PubMed

Bogdanowski, T; Rubisz-Brzezińska, J; Macura-Gina, M; Misiewicz, D

1990-01-01

In the clinic of dermatological surgery, I Department of Dermatology Silesian Medical Academy in Katowice 328 patients were treated surgically for granuloma teleangiectodes in the years 1973-1988. Two methods were used: excision of the lesion and curettage with electrocoagulation of the base of the lesion. After excision the wound was closed by approximation of its margins or local plastic procedure (285 cases) and by covering it with a free full-thickness skin graft (3 cases). Curettage and electrocoagulation was used in 43 cases, mainly due to the location of the lesion (in 90% on fingers). After granuloma excision no recurrences were observed, while after curettage and electrocoagulation recurrences developed in 20% of cases.

Endoscopic colloid cyst excision: surgical techniques and nuances.

PubMed

Azab, Waleed Abdelfattah; Najibullah, Mustafa; Yosef, Waleed

2017-06-01

Endoscopic excision of colloid cysts is currently well established as a minimally invasive and highly effective technique that is associated with less morbidity in comparison to microsurgical resection. Operative charts and videos of patients undergoing endoscopic colloid cyst excision were retrieved from the senior author's database of endoscopic procedures and reviewed. This revealed nine trans-foraminal and three trans-septal procedures. Description of the surgical techniques was then formulated. Variation of the technique is based on the specific patho-anatomical features of the colloid cyst being resected. For the trans-foraminal approach, we think that the rotational technique is associated with a more complete removal of the cyst wall and consequently lower recurrence rate.

The spectrum of skin biopsies and excisions in a pediatric skin center.

PubMed

Theiler, Martin; Neuhaus, Kathrin; Kerl, Katrin; Weibel, Lisa

2017-12-01

Little is known about the spectrum of pediatric skin disorders requiring biopsy/excision, their indication, impact on further management, and the accuracy of clinical diagnosis. We aimed to address these questions in the patient population seen at our Swiss University referral center for Pediatric Dermatology and Plastic Surgery. All skin biopsies/excisions performed in patients aged ≤ 16 years over a period of 2 years were retrospectively analyzed. A total of 506 samples were included. The majority of biopsies/excisions (n = 413, 82%) was performed for tumors, cysts, and hamartomas and 18% for other skin conditions. Malignant tumors were found in 12 samples (2%) from four patients. In 121 (24%) patients, the histopathology had an important impact on patient management. In 80 (16%) cases, the pathology did not match with the clinical diagnosis. In 382 (75%) cases, excision was the treatment of choice. Of these, the indication for surgery was based on patient's request in 181 (47%) cases. Surgical interventions for pediatric skin disorders are performed for diagnostic and therapeutic reasons. In this cohort, histopathology was essential for treatment in one quarter of cases. Skin tumors, cysts, and hamartomas often require excision during childhood, with families' request and esthetic considerations playing an important role. What is Known: • The spectrum of pediatric skin conditions has been studied in outpatient, inpatient, and emergency settings. • In contrast, no data exist on the spectrum of pediatric skin disorders undergoing biopsy/excision specifically. What is New: • We analyze biopsies/excisions in children, focusing on diagnosis, indication, and impact on patient management. • Surgical interventions for skin disorders in children are often performed for tumors and hamartomas with esthetic considerations playing a relevant role. If used for diagnostic purposes, they are often performed to confirm or rule out severe skin disease.

Regulatory mechanisms of RNA function: emerging roles of DNA repair enzymes.

PubMed

Jobert, Laure; Nilsen, Hilde

2014-07-01

The acquisition of an appropriate set of chemical modifications is required in order to establish correct structure of RNA molecules, and essential for their function. Modification of RNA bases affects RNA maturation, RNA processing, RNA quality control, and protein translation. Some RNA modifications are directly involved in the regulation of these processes. RNA epigenetics is emerging as a mechanism to achieve dynamic regulation of RNA function. Other modifications may prevent or be a signal for degradation. All types of RNA species are subject to processing or degradation, and numerous cellular mechanisms are involved. Unexpectedly, several studies during the last decade have established a connection between DNA and RNA surveillance mechanisms in eukaryotes. Several proteins that respond to DNA damage, either to process or to signal the presence of damaged DNA, have been shown to participate in RNA quality control, turnover or processing. Some enzymes that repair DNA damage may also process modified RNA substrates. In this review, we give an overview of the DNA repair proteins that function in RNA metabolism. We also discuss the roles of two base excision repair enzymes, SMUG1 and APE1, in RNA quality control.

Arsenic resistance in Pteris vittata L.: identification of a cytosolic triosephosphate isomerase based on cDNA expression cloning in Escherichia coli.

PubMed

Rathinasabapathi, Bala; Wu, Shan; Sundaram, Sabarinath; Rivoal, Jean; Srivastava, Mrittunjai; Ma, Lena Q

2006-12-01

Arsenic hyperaccumulator Pteris vittata L. (Chinese brake fern) grows well in arsenic-contaminated media, with an extraordinary ability to tolerate high levels of arsenic. An expression cloning strategy was employed to identify cDNAs for the genes involved in arsenic resistance in P. vittata. Excised plasmids from the cDNA library of P. vittata fronds were introduced into Escherichia coli XL-1 Blue and plated on medium containing 4 mM of arsenate, a common form of arsenic in the environment. The deduced amino acid sequence of an arsenate-resistant clone, PV4-8, had cDNA highly homologous to plant cytosolic triosephosphate isomerases (cTPI). Cell-free extracts of PV4-8 had 3-fold higher level of triosephosphate isomerase (TPI) specific activities than that found in E. coli XL-1 Blue and had a 42 kD fusion protein immunoreactive to polyclonal antibodies raised against recombinant Solanum chacoense cTPI. The PV4-8 cDNA complemented a TPI-deficient E. coli mutant. PV4-8 expression improved arsenate resistance in E. coli WC3110, a strain deficient in arsenate reductase but not in AW3110 deficient for the whole ars operon. This is consistent with the hypothesis that PV4-8 TPI increased arsenate resistance in E. coli by directly or indirectly functioning as an arsenate reductase. When E. coli tpi gene was expressed in the same vector, bacterial arsenate resistance was not altered, indicating that arsenate tolerance was specific to P. vittata TPI. Paradoxically, P. vittata TPI activity was not more resistant to inhibition by arsenate in vitro than its bacterial counterpart suggesting that arsenate resistance of conventional TPI reaction was not the basis for the cellular arsenate resistance. P. vittata TPI activity was inhibited by incubation with reduced glutathione while bacterial TPI was unaffected. Consistent with cTPI's role in arsenate reduction, bacterial cells expressing fern TPI had significantly greater per cent of cellular arsenic as arsenite compared to cells expressing E. coli TPI. Excised frond tissue infiltrated with arsenate reduced arsenate significantly more under light than dark. This research highlights a novel role for P. vittata cTPI in arsenate reduction.

Management of flat epithelial atypia on breast core biopsy may be individualized based on correlation with imaging studies.

PubMed

Calhoun, Benjamin C; Sobel, Amy; White, Richard L; Gromet, Matt; Flippo, Teresa; Sarantou, Terry; Livasy, Chad A

2015-05-01

Flat epithelial atypia of the breast commonly co-exists with atypical ductal hyperplasia, lobular neoplasia, and indolent forms of invasive carcinomas such as tubular carcinoma. Most patients with pure flat epithelial atypia on core biopsy undergo surgical excision to evaluate for carcinoma in the adjacent breast tissue. Studies to date have reported varying upgrade rates with most recommending follow-up excision. These studies have often lacked detailed radiographic correlation, central review by breast pathologists and information regarding the biology of the carcinomas identified upon excision. In this study, we report the frequency of upgrade to invasive carcinoma or ductal carcinoma in situ in excision specimens following a diagnosis of pure flat epithelial atypia on core biopsy. Radiographic correlation is performed for each case and grade/receptor status of detected carcinomas is reported. Seventy-three (73) core biopsies containing pure flat epithelial atypia were identified from our files, meeting inclusion criteria for the study. In the subsequent excision biopsies, five (7%) cases contained invasive carcinoma or ductal carcinoma in situ and seventeen (23%) contained atypical ductal hyperplasia or lobular neoplasia. All of the ductal carcinoma in situ cases with estrogen receptor results were estrogen receptor positive and intermediate grade. The invasive tumors were small (pT1a) hormone receptor-positive, HER2-negative, low-grade invasive ductal or tubular carcinomas with negative sentinel lymph-node biopsies. No upgrades were identified in the 14 patients who had all of their calcifications removed by the stereotactic core biopsy. Our rate of upgrade to carcinoma, once cases with discordant imaging are excluded, is at the lower end of the range reported in the literature. Given the low upgrade rate and indolent nature of the carcinomas associated with flat epithelial atypia, case management may be individualized based on clinical and radiographic findings. Excision may not be necessary for patients without remaining calcifications following core biopsy.

Design and application of a new series of gallbladder endoscopes that facilitate gallstone removal without gallbladder excision

NASA Astrophysics Data System (ADS)

Qiao, Tie; Huang, Wan-Chao; Luo, Xiao-Bing; Zhang, Yang-De

2012-01-01

In recent years, some Chinese doctors have proposed a new concept, gallstone removal without gallbladder excision, along with transition of the medical model. As there is no specialized endoscope for gallstone removal without gallbladder excision, we designed and produced a new series of gallbladder endoscopes and accessories that have already been given a Chinese invention patent (No. ZL200810199041.2). The design of these gallbladder endoscopes was based on the anatomy and physiology of the gallbladder, characteristics of gallbladder disease, ergonomics, and industrial design. This series of gallbladder endoscopes underwent clinical trials in two hospitals appointed by the State Administration of Traditional Chinese Medicine. The clinical trials showed that surgeries of gallstones, gallbladder polyps, and cystic duct calculus could be smoothly performed with these products. In summary, this series of gallbladder endoscopes is safe, reliable, and effective for gallstone removal without gallbladder excision. This note comprehensively introduces the research and design of this series of gallbladder endoscopes.

Ovarian tissue vitrification and heterotopic autologous transplantation in prepubertal Wistar rats.

PubMed

Wietcovsky, Leticia; Til, David; Salvador, Rafael Alonso; Amaral, Nicole Louise Lângaro; Senn, Alfred Paul; Amaral, Vera Lucia Lângaro

2018-03-15

To evaluate the efficiency of ovarian tissue heterotopic autografting after vitrification in prepubertal rats. Fragments of excised ovaries from prepubertal rats were used after assessing post-warming cellular viability, to determine the best vitrification protocol prior to retroauricular autografting. Pre-pubertal females (N=24) were castrated and divided into three group: Group 1 - fresh ovarian tissue transplantation; Group 2 - vitrified/warmed tissue transplantation; Group 3 - bilateral oophorectomy without transplantation. The ovarian fragments were exposed to solutions from the Ingamed® commercial kit, allocated in bacteriological loops and immersed in liquid nitrogen. Sixty days after transplantation, a vaginal mucus sample was collected for cytology tests, followed by sacrificing the animal, performing a cardiac puncture for collecting a blood sample to determine luteinizing hormone and estradiol levels, and excision of the transplanted fragment for histology tests. Vaginal cytology revealed that 87.5% of females from groups 1 and 2 had estrus while all females in Group 3 remained in diestrus. The mean LH value in groups 1 (0.08 mIU/mL) and 2 (0.34 mIU/mL) were statistically different from that of Group 3 (2.27 mIU/mL). E2 values did not differ between the groups. The histological analysis of Group 1 excised grafts versus those from Group 2 showed a higher percentage of primary follicles (62.5% vs. 12.5%), developing follicles (75% vs. 25%), corpus luteum (37.5% vs. 12.5%) and stromal region (100% vs. 87.5%). This study indicated that pre-pubertal ovarian tissue vitrification can be used to preserve fertility and to restore endocrine function in castrated rats.

Surgical excision of skin cancer: the importance of training.

PubMed

Salmon, P; Mortimer, N; Rademaker, M; Adams, L; Stanway, A; Hill, S

2010-01-01

Background Skin cancers are the most common malignancy in New Zealand and their treatment imparts a huge burden on the healthcare system both in terms of the cost of surgical intervention and in treatment delivery (estimates are in excess of NZ$33 million per annum for the year 2000). Currently in New Zealand, skin cancers are excised by dermatologists, general practitioners (GPs), GPs with a special interest in skin surgery (GPSIs) and specialist surgeons with diverse training backgrounds including ear, nose and throat, ophthalmic and general surgeons. To date there is scant literature evaluating complete excision rates following surgical treatment of skin cancer between these vocational groups. Objectives To review retrospectively pathology reports from all skin excisions sent to one private pathology laboratory over three consecutive months. The aim was to investigate the margins of excision and completeness of skin cancer surgery performed by each vocational group. Methods A retrospective analysis of skin pathology reports was undertaken for a 3-month period between April and June 2007. Raw data obtained from the pathology reports included diagnosis, completeness of excision, size of specimens, body site and vocational group of the medical practitioner performing the surgery. Results In total, 1532 lesions were excised: 432 benign and 1100 malignant. Six hundred and seven were from the head and neck. Dermatologists excised 276 lesions of which 93% were malignant, 55% were from the head and neck, and 0% were incompletely excised. GPs excised 633 lesions: 63% malignant, 30% head and neck, 23% incomplete excision of malignant lesions. GPSIs excised 368 lesions: 71% malignant, 35% head and neck, 21.5% incomplete malignant excision. Specialist surgeons excised 255 lesions: 72% malignant, 53% head and neck, 20% incomplete malignant excision. Conclusion GPs and GPSIs excised more benign lesions and had higher incomplete excision rates of skin cancer surgery than dermatologists. Incomplete excision rates for the vocational groups ranged from 0% to 45% depending on site and pathology.

The influence of the oestrous cycle on the radiation response of solid tumours

NASA Astrophysics Data System (ADS)

Swann, Patricia R.

Oestrogen increases the transcription of nitric oxide synthase, thus increasing nitric oxide production, which can result in vasodilation of blood vessels. Fluctuating levels of oestrogen throughout the menstrual cycle has the potential to affect tumour blood flow. Variations of blood supply to a solid tumour can influence tumour oxygenation and subsequently the percentage of hypoxic cells. As hypoxic cells are more resistant to radiation than well-oxygenated cells, this could potentially affect the radiation response of the tumour. This project evaluated the impact of the oestrous stage on the radiation response of BCHT, RIF-1 and SCCvii tumours in syngeneic C3H mice. The oestrous cycle consists of the following stages, pro-oestrus, oestrus, metoestrus and dioestrus and each stage can be determined by the cellular composition of vaginal smears. The peak of oestrogen occurs in the ovulatory phase and a second smaller peak occurs in dioestrus. Subcutaneous tumour were treated at a volume of 200 - 250 mm3 with local irradiation of 10 Gy ionising radiation at different stages of the oestrous cycle. Tumours were excised either immediately or 24 hours after irradiation and disaggregated into a single cell suspension. Tumour cell survival was assessed by clonogenic assay of the excised tumour relative to untreated tumours excised at the corresponding oestrous stage. Tumours irradiated in oestrus consistently produced the lowest surviving fraction after immediate and delayed excision. Tumours irradiated in pro-oestrus and excised immediately after irradiation, showed a two-fold increase in surviving fraction compared to tumours irradiated in oestrus. The surviving fractions of tumours excised 24 hours after irradiation were less than for tumours excised immediately after irradiation. Surviving fractions of irradiated, clamped KHT tumours were independent of oestrous stage. To confirm that these oestrous stage dependent changes were due to changes in tumour perfusion, the degree of transient perfusion in the tumours was assessed. This used a fluorescent double-staining technique by intravenous injection of the fluorescent dyes Hoechst 33342 and diheptyloxacarbocyanine with a 20 minute interval between dye administrations. These dyes stain functional blood vessels and can be viewed under the fluorescent microscope. Regions of vasculature stained with both dyes indicate constant perfusion throughout the experiment, whereas only one dye indicates mismatch or transient perfusion. Tumour vasculature that experiences intermittent perfusion will result in areas of acute hypoxia that can impact on the radiation response of the tumour. The results shows that in oestrus, KHT and RIF-1 tumours showed the lowest proportion of transient perfusion, where as this oestrous stage produced the most mismatch perfusion in the SCCvii tumour. The metastatic spread of KHT tumour cells was influenced by the oestrous cycle. Fractionated irradiation of a primary tumour during metoestrus and dioestrus showed less tumour control by radiation when compared to tumours irradiated in oestrus. The intravenous injection of KHT tumour cells in oestrus and dioestrus also produced a less metastatic burden to the lungs than cells injected in pro-oestrus and metoestrus. The results of this project suggest that there are oestrous stage dependent effects that could alter the radiation response of tumours.

Trigeminocardiac reflex during endoscopic juvenile nasopharyngeal angiofibroma surgery: an appraisal.

PubMed

Sharma, Shilpee Bhatia; Janakiram, Trichy Narayanan; Baxi, Hina; Chinnasamy, Balamurugan

2017-07-01

Juvenile nasopharyngeal angiofibroma is a locally aggressive benign tumour which has propensity to erode the skull base. The tumour spreads along the pathways of least resistance and is in close proximity to the extracranial part of trigeminal nerve. Advancements in expanded approaches for endoscopic excision of tumours in infratemporal fossa and pterygopalatine fossa increase the vulnerability for the trigeminocardiac reflex. The manipulation of nerve and its branches during tumour dissection can lead to sensory stimulation and thus inciting the reflex. The aim of our study is to report the occurrence of trigeminocardiac reflex in endoscopic excision of juvenile nasopharyngeal angiofibroma. To describe the occurence of trigeminocardiac reflex during endoscopic endonasal excision of juvenile nasopharyngeal angiofibroma. We studied the occurrence of TCR in 15 patients (out of 242 primary cases and 52 revision cases) operated for endoscopic endonasal excision of JNA. The drop in mean arterial blood pressure and heart rate were observed and measured. To the best of our knowledge of English literature, this is the first case series reporting TCR as complication in endoscopic excision of JNA. occurence of this reflex has been mentioned in various occular, maxillofacial surgeries but its occurence during endoscopic excision of JNA has never been reported before. Manifestation of trigeminocardiac reflex during surgery can alter the course of the surgery and is a potential threat to life. It is essential for the anesthetist and surgeons to be familiar with the presentations, preventive measures and management protocols.

8-Oxoguanine DNA glycosylase1-driven DNA repair-A paradoxical role in lung aging.

PubMed

German, Peter; Saenz, David; Szaniszlo, Peter; Aguilera-Aguirre, Leopoldo; Pan, Lang; Hegde, Muralidhar L; Bacsi, Attila; Hajas, Gyorgy; Radak, Zsolt; Ba, Xueqing; Mitra, Sankar; Papaconstantinou, John; Boldogh, Istvan

2017-01-01

Age-associated changes in lung structure and function are some of the most important predictors of overall health, cognitive activities and longevity. Common to all aging cells is an increase in oxidatively modified DNA bases, primarily 8-oxo-7,8-dihydroguanine (8-oxoG). It is repaired via DNA base excision repair pathway driven by 8-oxoguanine DNA glycosylase-1 (OGG1-BER), whose role in aging has been the focus of many studies. This study hypothesizes that signaling and consequent gene expression during cellular response to OGG1-BER "wires" senescence/aging processes. To test OGG1-BER was mimicked by repeatedly exposing diploid lung fibroblasts cells and airways of mice to 8-oxoG base. Results showed that repeated exposures led to G1 cell cycle arrest and pre-matured senescence of cultured cells in which over 1000 genes were differentially expressed -86% of them been identical to those in naturally senesced cells. Gene ontology analysis of gene expression displayed biological processes driven by small GTPases, phosphoinositide 3-kinase and mitogen activated kinase cascades both in cultured cells and lungs. These results together, points to a new paradigm about the role of DNA damage and repair by OGG1 in aging and age-associated disease processes. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

"Ancient" schwannoma of the submandibular gland: A case report and literature review.

PubMed

Ho, Che-Fang; Wu, Pei-Wen; Lee, Ta-Jen; Huang, Chien-Chia

2017-12-01

Schwannomas are solitary neurogenic tumors that arise from cells of the neural sheath. Ancient schwannoma is a relatively rare variant of schwannoma, characterized by increased cellularity and atypia. These cellular changes could be confusing and make the accurate pathologic diagnosis difficult. A 36-year-old man presented with painless swelling in left submandibular region for more than 2 years. The computed tomography confirmed a well-defined cystic lesion in the left submandibular space, which caused superior and posterior displacement of the left submandibular gland. Surgical excision was performed and the pathology confirmed the diagnosis of ancient schwannoma. To our knowledge, this patient is the second case of primary submandibular ancient schwannoma reported in the literatures. The patient underwent tumor resection and postoperative recovery was uneventful. There were no nerve deficits after the operation. There was no recurrence within 1 year of follow-up. Schwannoma originated from the submandibular gland is extremely rare and only a few cases have been reported. Ancient schwannoma is an even more rare tumor. The increased cellularity and atypia of ancient schwannoma can resemble features of malignancy. Great care must be taken to make differential diagnosis with fibrosarcomas and malignant schwannoma. Copyright © 2017 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.

Near-Infrared Confocal Laser Reflectance Cytoarchitectural Imaging of the Substantia Nigra and Cerebellum in the Fresh Human Cadaver.

PubMed

Cheyuo, Cletus; Grand, Walter; Balos, Lucia L

2017-01-01

Cytoarchitectural neuroimaging remains critical for diagnosis of many brain diseases. Fluorescent dye-enhanced, near-infrared confocal in situ cellular imaging of the brain has been reported. However, impermeability of the blood-brain barrier to most fluorescent dyes limits clinical utility of this modality. The differential degree of reflectance from brain tissue with unenhanced near-infrared imaging may represent an alternative technique for in situ cytoarchitectural neuroimaging. We assessed the utility of unenhanced near-infrared confocal laser reflectance imaging of the cytoarchitecture of the cerebellum and substantia nigra in 2 fresh human cadaver brains using a confocal near-infrared laser probe. Cellular images based on near-infrared differential reflectance were captured at depths of 20-180 μm from the brain surface. Parts of the cerebellum and substantia nigra imaged using the probe were subsequently excised and stained with hematoxylin and eosin for histologic correlation. Near-infrared reflectance imaging revealed the 3-layered cytoarchitecture of the cerebellum, with Purkinje cells appearing hyperreflectant. In the substantia nigra, neurons appeared hyporeflectant with hyperreflectant neuromelanin cytoplasmic inclusions. Cytoarchitecture of the cerebellum and substantia nigra revealed on near-infrared imaging closely correlated with the histology on hematoxylin-eosin staining. We showed that unenhanced near-infrared reflectance imaging of fresh human cadaver brain can reliably identify and distinguish neurons and detailed cytoarchitecture of the cerebellum and substantia nigra. Copyright © 2016 Elsevier Inc. All rights reserved.

Flat epithelial atypia of the breast on core needle biopsy: an indication for surgical excision.

PubMed

Sohn, Vance; Porta, Rees; Brown, Tommy

2011-11-01

Flat epithelial atypia (FEA) is an increasingly diagnosed breast lesion yet there remains a paucity of data regarding these findings and their clinical significance. By determining the pathologic concordance rate, we sought to evaluate the indications for surgical intervention for FEAs diagnosed on core needle biopsy (CNB). Using a retrospective review of an international pathology referral center database, we included all breast CNB specimens with FEA as the most advanced diagnosis that underwent surgical excision. Patient demographics, caliber of biopsy needle, and pathology results were then analyzed. Between 2000 and 2009, 463 FEAs were diagnosed among 15,000 specimens referred for expert opinion. Twenty-four lesions (5%) met inclusion criteria. Sampling ranged from 8- to 18-guage needles. Two lesions (8.4%) were upgraded after surgical excision; one patient was found to have infiltrating ductal carcinoma and another with tubular carcinoma. Twelve patients who were diagnosed with FEA did not undergo surgical excision but had no immediate evidence of malignancy. Based on the 8.4% upgrade rate, FEA diagnosed on CNB requires follow-up surgical excision. Regardless of CNB caliber, the risk of sampling error precludes nonoperative management and FEA should be considered an at-risk lesion until more studies and pooled analysis prove otherwise.

Low-grade central osteosarcoma of distal femur, resembling fibrous dysplasia

PubMed Central

Vasiliadis, Haris S; Arnaoutoglou, Christina; Plakoutsis, Sotiris; Doukas, Michalis; Batistatou, Anna; Xenakis, Theodoros A

2013-01-01

We report a case of a 32 year-old male, admitted for a lytic lesion of the distal femur. One month after the first X-ray, clinical and imaging deterioration was evident. Open biopsy revealed fibrous dysplasia. Three months later, the lytic lesion had spread to the whole distal third of the femur reaching the articular cartilage. The malignant clinical and imaging features necessitated excision of the lesion and reconstruction with a custom-made total knee arthroplasty. Intra-operatively, no obvious soft tissue infiltration was evident. Nevertheless, an excision of the distal 15.5 cm of the femur including 3.0 cm of the surrounding muscles was finally performed. The histological examination of the excised specimen revealed central low-grade osteosarcoma. Based on the morphological features of the excised tumor, allied to the clinical findings, the diagnosis of low-grade central osteosarcoma was finally made although characters of a fibrous dysplasia were apparent. Central low-grade osteosarcoma is a rare, well-differentiated sub-type of osteosarcoma, with clinical, imaging, and histological features similar to benign tumours. Thus, initial misdiagnosis is usual with the condition commonly mistaken for fibrous dysplasia. Central low-grade osteosarcoma is usually treated with surgery alone, with rare cases of distal metastases. However, regional recurrence is quite frequent after close margin excision. PMID:24147271

Improvement of a yeast self-excising integrative vector by prevention of expression leakage of the intronated Cre recombinase gene during plasmid maintenance in Escherichia coli.

PubMed

Agaphonov, Michael O

2017-12-01

The use of plasmids possessing a regulatable gene coding for a site-specific recombinase together with its recognition sequences significantly facilitates genome manipulations since it allows self-excision of the portion of the genetic construct integrated into the host genome. Stable maintenance of such plasmids in Escherichia coli, which is used for plasmid preparation, requires prevention of recombinase synthesis in this host, which can be achieved by interrupting the recombinase gene with an intron. Based on this approach, Saccharomyces cerevisiae and Hansenula polymorpha self-excising vectors possessing intronated gene for Cre recombinase and its recognition sites (LoxP) were previously constructed. However, this work shows instability of the H. polymorpha vectors during plasmid maintenance in E. coli cells. This could be due to recombination between the loxP sites caused by residual expression of the cre gene. Prevention of translation reinitiation on an internal methionine codon completely solved this problem. A similar modification was made in a self-excising vector designed for S. cerevisiae. Apart from substantial improvement of yeast self-excising vectors, the obtained results also narrow down the essential part of Cre sequence. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Flexible CO2 laser and submucosal gel injection for safe endoluminal resection in the intestines.

PubMed

Au, Joyce T; Mittra, Arjun; Wong, Joyce; Carpenter, Susanne; Carson, Joshua; Haddad, Dana; Monette, Sebastien; Ezell, Paula; Patel, Snehal; Fong, Yuman

2012-01-01

The CO(2) laser's unique wavelength of 10.6 μm has the advantage of being readily absorbed by water but historically limited it to line-of-sight procedures. Through recent technological advances, a flexible CO(2) laser fiber has been developed and holds promise for endoluminal surgery. We examined whether this laser, along with injection of a water-based gel in the submucosal space, will allow safe dissection of the intestines and enhance the potential of this tool for minimally invasive surgery. Using an ex vivo model with porcine intestines, spot ablation was performed with the flexible CO(2) laser at different power settings until transmural perforation. Additionally, excisions of mucosal patches were performed by submucosal dissection with and without submucosal injection of a water-based gel. With spot ablation at 5 W, none of the specimens was perforated by 5 min, which was the maximum recorded time. The time to perforation was significantly shorter with increased laser power, and gel pretreatment protected the intestines against spot ablation, increasing the time to perforation from 6 to 37 s at 10 W and from 1 to 7 s at 15 W. During excision of mucosal patches, 56 and 83% of untreated intestines perforated at 5 and 10 W, respectively. Gel pretreatment prior to excision protected all intestines against perforation. These specimens were verified to be intact by inflation with air to over 100 mmHg. Furthermore, excision of the mucosal patch was complete in gel-pretreated specimens, whereas 22% of untreated specimens had residual islands of mucosa after excision. The flexible CO(2) laser holds promise as a precise dissection and cutting tool for endoluminal surgery of the intestines. Pretreatment with a submucosal injection of a water-based gel protects the intestines from perforation during ablation and mucosal dissection.

Flexible CO2 laser and submucosal gel injection for safe endoluminal resection in the intestines

PubMed Central

Au, Joyce T.; Mittra, Arjun; Wong, Joyce; Carpenter, Susanne; Carson, Joshua; Haddad, Dana; Monette, Sebastien; Ezell, Paula; Patel, Snehal

2012-01-01

Background The CO2 laser’s unique wavelength of 10.6 µm has the advantage of being readily absorbed by water but historically limited it to line-of-sight procedures. Through recent technological advances, a flexible CO2 laser fiber has been developed and holds promise for endoluminal surgery. We examined whether this laser, along with injection of a water-based gel in the submucosal space, will allow safe dissection of the intestines and enhance the potential of this tool for minimally invasive surgery. Methods Using an ex vivo model with porcine intestines, spot ablation was performed with the flexible CO2 laser at different power settings until transmural perforation. Additionally, excisions of mucosal patches were performed by submucosal dissection with and without submucosal injection of a water-based gel. Results With spot ablation at 5 W, none of the specimens was perforated by 5 min, which was the maximum recorded time. The time to perforation was significantly shorter with increased laser power, and gel pretreatment protected the intestines against spot ablation, increasing the time to perforation from 6 to 37 s at 10 W and from 1 to 7 s at 15 W. During excision of mucosal patches, 56 and 83% of untreated intestines perforated at 5 and 10 W, respectively. Gel pretreatment prior to excision protected all intestines against perforation. These specimens were verified to be intact by inflation with air to over 100 mmHg. Furthermore, excision of the mucosal patch was complete in gel-pretreated specimens, whereas 22% of untreated specimens had residual islands of mucosa after excision. Conclusion The flexible CO2 laser holds promise as a precise dissection and cutting tool for endoluminal surgery of the intestines. Pretreatment with a submucosal injection of a water-based gel protects the intestines from perforation during ablation and mucosal dissection. PMID:21898027

Spontaneous germline excision of Tol1, a DNA-based transposable element naturally occurring in the medaka fish genome.

PubMed

Watanabe, Kohei; Koga, Hajime; Nakamura, Kodai; Fujita, Akiko; Hattori, Akimasa; Matsuda, Masaru; Koga, Akihiko

2014-04-01

DNA-based transposable elements are ubiquitous constituents of eukaryotic genomes. Vertebrates are, however, exceptional in that most of their DNA-based elements appear to be inactivated. The Tol1 element of the medaka fish, Oryzias latipes, is one of the few elements for which copies containing an undamaged gene have been found. Spontaneous transposition of this element in somatic cells has previously been demonstrated, but there is only indirect evidence for its germline transposition. Here, we show direct evidence of spontaneous excision in the germline. Tyrosinase is the key enzyme in melanin biosynthesis. In an albino laboratory strain of medaka fish, which is homozygous for a mutant tyrosinase gene in which a Tol1 copy is inserted, we identified de novo reversion mutations related to melanin pigmentation. The gamete-based reversion rate was as high as 0.4%. The revertant fish carried the tyrosinase gene from which the Tol1 copy had been excised. We previously reported the germline transposition of Tol2, another DNA-based element that is thought to be a recent invader of the medaka fish genome. Tol1 is an ancient resident of the genome. Our results indicate that even an old element can contribute to genetic variation in the host genome as a natural mutator.

‘Serpent in the spine’: a case of giant spinal ependymoma of cervicothoracic spine

PubMed Central

Arrifin, Arlizan; Kaliaperumal, Chandrasekaran; Keohane, Catherine; O'Sullivan, Michael

2012-01-01

We describe a case of giant spinal ependymoma of cervicothoracic spine in a 30-year-old lady who presented with progressive spastic paraparesis and significant combined upper and lower motor neuron signs in her lower limbs over a 1-year period. She also had upper limb small muscle wasting with absent reflexes and diminished sensation. She was wheel chair bound with involvement of sphincters. Neuroimaging revealed a uniformly enhancing intramedullary lesion from C2–T3 level with associated syringomyelia. She underwent a complete excision of this World Health Organisation (WHO) II cellular ependymoma, resulting in significant clinical outcome and improvement in bladder and bowel function. PMID:22739334

Breast surgery techniques: preoperative bracketing wire localization by surgeons.

PubMed

Burkholder, Hans C; Witherspoon, Laura E; Burns, R Phillip; Horn, Jeffrey S; Biderman, Michael D

2007-06-01

With the development of expertise in image guidance for breast surgery, many surgeons now perform preoperative wire localization themselves. Use of a single wire versus multiple wires to bracket a radiographic breast abnormality has previously been described, although benefits of this technique based on clinical outcomes such as margin status, tissue volume removed, and re-excision rates have not been established. This study is a retrospective analysis of wire-localized breast biopsies performed by 14 surgeons over 29 months; stereotactic and ultrasound guidance were used. During this time, 489 wire localizations were done, of which 159 used multiple wires. Two hundred eleven of these biopsies were done for malignant disease, 86 using multiple wires. After controlling for tumor node metastases stage, single and multiple wire placements were compared using endpoints of margin status, need for re-excision, and total volume of tissue removed. Neither margin status nor re-excision was related to the number of wires placed. However, the number of wires placed was significantly related to the total volume of tissue removed. Use of more than one localizing wire was associated with greater volume of tissue removal (measured in centimeters cubed) in benign disease (46 vs 25, P < 0.001), equivalent volumes in stage 0 disease (73 vs 67), less volume in stage 1 disease (113 vs 164), and less volume in stages 2 through 4 (158 vs 207, P = 0.03). Outcomes based on surgeon case volume during the study period demonstrated that low- (1-40), medium- (41-80), and high-volume (>80) surgeons did not differ in the type or stage of breast pathology treated. Surgeons with high case volumes were more likely to place multiple localizing wires (P < 0.001) and were more likely to do a breast-conserving procedure if re-excision was performed (P < 0.018). Surgeons with low case volumes were more likely to perform a re-excision (P < 0.025). Surgeon experience has a positive impact on quality outcome measures such as performance of a definitive procedure at the time of initial surgery and use of breast-conserving procedures at the time of re-excision. Multiple wire localization can be used to significantly reduce the volume of breast tissue removed in malignant disease without sacrificing margin status or increasing the need for future re-excision.

Extralevator Abdominoperineal Excision for Low Rectal Cancer—Extensive Surgery to Be Used With Discretion Based on 3-Year Local Recurrence Results

PubMed Central

Prytz, Mattias; Angenete, Eva; Bock, David; Haglind, Eva

2016-01-01

Objectives: The aim of this prospective registry-based population study was to investigate the efficacy of extralevator abdominoperineal excision (ELAPE) regarding local recurrence rates within 3 years after surgery. Background: Local recurrence of rectal cancer is more common after abdominoperineal excision (APE) than after anterior resection. Extralevator abdominoperineal excision was introduced to address this problem. No large-scale studies with long-term oncological outcomes have been published. Methods: All Swedish patients operated on with an APE and registered in the Swedish ColoRectal Cancer Registry 2007 to 2009 were included (n = 1397) and analyzed with emphasis on the perineal part of the operation. Local recurrence at 3 years was collected from the registry. Results: The local recurrence rates at 3 years [median follow-up, 3.43 years (APE, 3.37 years; ELAPE, 3.41 years; not stated: 3.43 years)] were significantly higher for ELAPE compared with APE (relative risk, 4.91). Perioperative perforation was also associated with an increased risk of local recurrence (relative risk, 3.62). There was no difference in 3-year overall survival between APE and ELAPE. In the subgroup of patients with very low tumors (≤4 cm from the anal verge), no significant difference in the local recurrence rate could be observed. Conclusions: Extralevator abdominoperineal excision results in a significantly increased 3-year local recurrence rate as compared with standard APE. Intraoperative perforation seems to be an important risk factor for local recurrence. In addition to significantly increased 3-year local recurrence rates, the significantly increased incidence of wound complications leads to the conclusion that ELAPE should only be considered in selected patients at risk of intraoperative perforation. PMID:25906414

Olfactory groove meningioma: discussion of clinical presentation and surgical outcomes following excision via the subcranial approach.

PubMed

Pepper, Jon-Paul; Hecht, Sarah L; Gebarski, Stephen S; Lin, Erin M; Sullivan, Stephen E; Marentette, Lawrence J

2011-11-01

To describe surgical outcomes and radiographic features of olfactory groove meningiomas treated by excision through the subcranial approach. Special emphasis is placed on paranasal sinus and orbit involvement. Retrospective review of a series of patients. Nineteen patients underwent excision of olfactory groove meningioma (OGM) via the transglabellar/subcranial approach between December 1995 and November 2009. Nine patients had previously undergone prior resection at outside institutions, and four had prior radiotherapy in addition to a prior excision. Transglabellar/subcranial surgical approach to the anterior skull base was performed. Tumor histology included three World Health Organization (WHO) grade III lesions, one WHO grade II lesion, and 15 WHO grade I lesions. Fourteen patients had evidence of extension into the paranasal sinuses, with the ethmoid sinus being most commonly involved. Kaplan-Meier estimates of mean overall and disease-free survival were 121.45 months and 93.03 months, respectively. The mean follow-up interval was 41.0 months, and at the time of data analysis three patients had recurrent tumors. Seven (36.8%) patients experienced a major complication in the perioperative period; there were no perioperative mortalities. Orbit invasion was observed in four patients, with optic nerve impingement in 11 patients. Of these, three patients had long-term diplopia. No patients experienced worsening of preoperative visual acuity. Olfactory groove meningiomas demonstrate a propensity to spread into the paranasal sinuses, particularly in recurrent cases. Given a tendency for infiltrative recurrence along the skull base, this disease represents an important area of collaboration between neurosurgery and otolaryngology. The subcranial approach offers excellent surgical access for excision, particularly for recurrences that involve the paranasal sinuses and optic apparatus. Copyright © 2011 The American Laryngological, Rhinological, and Otological Society, Inc.

Mucosal excision and suturing for obesity and GERD.

PubMed

Légner, András; Tsuboi, Kazuto; Stadlhuber, Rudolf; Yano, Fumiaki; Halvax, Peter; Hunt, Brandon; Penka, Wayne; Filipi, Charles J

2013-12-01

Suture and staple-based endoluminal devices for gastroesophageal reflux disease (GERD) and obesity have failed to demonstrate long-term efficacy. To demonstrate the feasibility of mucosal excision and full-thickness suture apposition of the excision beds to create sufficient scar tissue formation at the gastroesophageal junction for the intraluminal treatment of GERD or obesity. Survival animal experiments. Seven mongrel dogs. Interventions. Under general endotracheal anesthesia, a Barostat test was performed on 4 dogs. A mucosal excision device was introduced through the esophagus into the proximal stomach. Two to 4 mucosal excisions were performed on all dogs at or just below the gastroesophageal junction and the mucosal pieces were removed. After hemostasis, an intraluminal suturing instrument was introduced and either 2 or 4 sutures were placed through the excision beds to bring them into apposition. These were tied and the suture strands cut. All dogs were survived for 2 months. End-term endoscopies were performed, and a repeat Barostat procedure was performed on the animals undergoing an antireflux procedure. After euthanasia the stomachs were explanted, examined, photographed, and sectioned for histologic examination. All dogs survived without complication. In the 4 GERD dogs, the Barostat studies demonstrated a significant decrease in gastroesophageal junction compliance. In the 3 dogs undergoing the obesity procedure, the gastric outlet apposition to a 6-mm endoscope was satisfactory with full insufflation and the desired scarring was seen on histologic examination. It is possible to create adequate gastroesophageal junction scarring for the treatment of GERD and obesity. A clinical pilot study will be initiated.

Oxidized Guanine Base Lesions Function in 8-Oxoguanine DNA Glycosylase-1-mediated Epigenetic Regulation of Nuclear Factor κB-driven Gene Expression*

PubMed Central

Pan, Lang; Hao, Wenjing; Ba, Xueqing

2016-01-01

A large percentage of redox-responsive gene promoters contain evolutionarily conserved guanine-rich clusters; guanines are the bases most susceptible to oxidative modification(s). Consequently, 7,8-dihydro-8-oxoguanine (8-oxoG) is one of the most abundant base lesions in promoters and is primarily repaired via the 8-oxoguanine DNA glycosylase-1 (OOG1)-initiated base excision repair pathway. In view of a prompt cellular response to oxidative challenge, we hypothesized that the 8-oxoG lesion and the cognate repair protein OGG1 are utilized in transcriptional gene activation. Here, we document TNFα-induced enrichment of both 8-oxoG and OGG1 in promoters of pro-inflammatory genes, which precedes interaction of NF-κB with its DNA-binding motif. OGG1 bound to 8-oxoG upstream from the NF-κB motif increased its DNA occupancy by promoting an on-rate of both homodimeric and heterodimeric forms of NF-κB. OGG1 depletion decreased both NF-κB binding and gene expression, whereas Nei-like glycosylase-1 and -2 had a marginal effect. These results are the first to document a novel paradigm wherein the DNA repair protein OGG1 bound to its substrate is coupled to DNA occupancy of NF-κB and functions in epigenetic regulation of gene expression. PMID:27756845

Replication-mediated disassociation of replication protein A-XPA complex upon DNA damage: implications for RPA handing off.

PubMed

Jiang, Gaofeng; Zou, Yue; Wu, Xiaoming

2012-08-01

RPA (replication protein A), the eukaryotic ssDNA (single-stranded DNA)-binding protein, participates in most cellular processes in response to genotoxic insults, such as NER (nucleotide excision repair), DNA, DSB (double-strand break) repair and activation of cell cycle checkpoint signalling. RPA interacts with XPA (xeroderma pigmentosum A) and functions in early stage of NER. We have shown that in cells the RPA-XPA complex disassociated upon exposure of cells to high dose of UV irradiation. The dissociation required replication stress and was partially attributed to tRPA hyperphosphorylation. Treatment of cells with CPT (camptothecin) and HU (hydroxyurea), which cause DSB DNA damage and replication fork collapse respectively and also leads to the disruption of RPA-XPA complex. Purified RPA and XPA were unable to form complex in vitro in the presence of ssDNA. We propose that the competition-based RPA switch among different DNA metabolic pathways regulates the dissociation of RPA with XPA in cells after DNA damage. The biological significances of RPA-XPA complex disruption in relation with checkpoint activation, DSB repair and RPA hyperphosphorylation are discussed.

Recruitment of Fanconi Anemia and Breast Cancer Proteins to DNA Damage Sites is differentially Governed by Replication

PubMed Central

Shen, Xi; Do, Huong; Li, Yongjian; Chung, Woo-Hyun; Tomasz, Maria; de Winter, Johan P.; Xia, Bing; Elledge, Stephen J.; Wang, Weidong; Li, Lei

2009-01-01

Summary Fanconi anemia (FA) is characterized by cellular hypersensivity to DNA crosslinking agents, but how the Fanconi pathway protects cells from DNA crosslinks and whether FA proteins act directly on crosslinks remains unclear. We developed a chromatin-IP-based strategy termed eChIP and detected association of multiple FA proteins with DNA crosslinks in vivo. Inter-dependence analyses revealed that crosslink-specific enrichment of various FA proteins is controlled by distinct mechanisms. BRCA-related FA proteins (BRCA2, FANCJ/BACH1, and FANCN/PALB2), but not FA core and I/D2 complexes, require replication for their crosslink association. FANCD2, but not FANCJ and FANCN, requires the FA core complex for its recruitment. FA core complex requires nucleotide excision repair proteins XPA and XPC for its association. Consistent with the distinct recruitment mechanism, recombination-independent crosslink repair was inversely affected in cells deficient of FANC-core versus BRCA-related FA proteins. Thus, FA proteins participate in distinct DNA damage response mechanisms governed by DNA replication status. PMID:19748364

Imaging Electrically Evoked Micromechanical Motion within the Organ of Corti of the Excised Gerbil Cochlea

PubMed Central

Karavitaki, K. Domenica; Mountain, David C.

2007-01-01

The outer hair cell (OHC) of the mammalian inner ear exhibits an unusual form of somatic motility that can follow membrane-potential changes at acoustic frequencies. The cellular forces that produce this motility are believed to amplify the motion of the cochlear partition, thereby playing a key role in increasing hearing sensitivity. To better understand the role of OHC somatic motility in cochlear micromechanics, we developed an excised cochlea preparation to visualize simultaneously the electrically-evoked motion of hundreds of cells within the organ of Corti (OC). The motion was captured using stroboscopic video microscopy and quantified using cross-correlation techniques. The OC motion at ∼2–6 octaves below the characteristic frequency of the region was complex: OHC, Deiter's cell, and Hensen's cell motion were hundreds of times larger than the tectorial membrane, reticular lamina (RL), and pillar cell motion; the inner rows of OHCs moved antiphasic to the outer row; OHCs pivoted about the RL; and Hensen's cells followed the motion of the outer row of OHCs. Our results suggest that the effective stimulus to the inner hair cell hair bundles results not from a simple OC lever action, as assumed by classical models, but by a complex internal motion coupled to the RL. PMID:17277194

Cloning of a human homolog of the yeast nucleotide excision repair gene MMS19 and interaction with transcription repair factor TFIIH via the XPB and XPD helicases.

PubMed

Seroz, T; Winkler, G S; Auriol, J; Verhage, R A; Vermeulen, W; Smit, B; Brouwer, J; Eker, A P; Weeda, G; Egly, J M; Hoeijmakers, J H

2000-11-15

Nucleotide excision repair (NER) removes UV-induced photoproducts and numerous other DNA lesions in a highly conserved 'cut-and-paste' reaction that involves approximately 25 core components. In addition, several other proteins have been identified which are dispensable for NER in vitro but have an undefined role in vivo and may act at the interface of NER and other cellular processes. An intriguing example is the Saccharomyces cerevisiae Mms19 protein that has an unknown dual function in NER and RNA polymerase II transcription. Here we report the cloning and characterization of a human homolog, designated hMMS19, that encodes a 1030 amino acid protein with 26% identity and 51% similarity to S.cerevisiae Mms19p and with a strikingly similar size. The expression profile and nuclear location are consistent with a repair function. Co-immunoprecipitation experiments revealed that hMMS19 directly interacts with the XPB and XPD subunits of NER-transcription factor TFIIH. These findings extend the conservation of the NER apparatus and the link between NER and basal transcription and suggest that hMMS19 exerts its function in repair and transcription by interacting with the XPB and XPD helicases.

Strand-specific Recognition of DNA Damages by XPD Provides Insights into Nucleotide Excision Repair Substrate Versatility*

PubMed Central

Buechner, Claudia N.; Heil, Korbinian; Michels, Gudrun; Carell, Thomas; Kisker, Caroline; Tessmer, Ingrid

2014-01-01

Recognition and removal of DNA damages is essential for cellular and organismal viability. Nucleotide excision repair (NER) is the sole mechanism in humans for the repair of carcinogenic UV irradiation-induced photoproducts in the DNA, such as cyclobutane pyrimidine dimers. The broad substrate versatility of NER further includes, among others, various bulky DNA adducts. It has been proposed that the 5′-3′ helicase XPD (xeroderma pigmentosum group D) protein plays a decisive role in damage verification. However, despite recent advances such as the identification of a DNA-binding channel and central pore in the protein, through which the DNA is threaded, as well as a dedicated lesion recognition pocket near the pore, the exact process of target site recognition and verification in eukaryotic NER still remained elusive. Our single molecule analysis by atomic force microscopy reveals for the first time that XPD utilizes different recognition strategies to verify structurally diverse lesions. Bulky fluorescein damage is preferentially detected on the translocated strand, whereas the opposite strand preference is observed for a cyclobutane pyrimidine dimer lesion. Both states, however, lead to similar conformational changes in the resulting specific complexes, indicating a merge to a “final” verification state, which may then trigger the recruitment of further NER proteins. PMID:24338567

Xeroderma pigmentosum in Ghanaians: a report of three cases and review of literature.

PubMed

Adu, E J

2014-01-01

Xeroderma pigmentosum is an autosomal recessive disease with sun sensitivity, photophobia, early onset of freckling, and subsequent neoplastic changes on sun-exposed surfaces. There is cellular hypersensitivity to UV radiation and to certain chemicals in association with abnormal DNA repair. Patients with defective DNA nucleotide excision repair (NER) have defects in one of seven NER genes; xeroderma pigmentosum variants have normal NER and a defect in a polymerase gene. This is a case presentation of three patients with the features of xeroderma pigmentosum, aged 48, 15, and 14 years. The latter two patients were females. Each presented with areas of hyper-and hypo-pigmentation over sun exposed body surfaces. Each patient had a minimum of two cutaneous malignancies, distributed on the upper chest, face or scalp. The first and third patients had their lesions surgically excised and the defects were skin grafted. The second patient was treated with radiotherapy. All the lesions presented were confirmed histologically as squamous cell carcinoma. No recurrence of the malignancies has been noticed. Xeroderma pigmentosum is not rare in Ghana. Early recognition of the disease is necessary to avoid morbidity and mortality from malignant complications. The use of other treatment modalities such as sunscreens, oral retinoids, and chemical therapy with 5-fluorouracil is discussed.

In vivo cellular imaging with microscopes enabled by MEMS scanners

NASA Astrophysics Data System (ADS)

Ra, Hyejun

High-resolution optical imaging plays an important role in medical diagnosis and biomedical research. Confocal microscopy is a widely used imaging method for obtaining cellular and sub-cellular images of biological tissue in reflectance and fluorescence modes. Its characteristic optical sectioning capability also enables three-dimensional (3-D) image reconstruction. However, its use has mostly been limited to excised tissues due to the requirement of high numerical aperture (NA) lenses for cellular resolution. Microscope miniaturization can enable in vivo imaging to make possible early cancer diagnosis and biological studies in the innate environment. In this dissertation, microscope miniaturization for in vivo cellular imaging is presented. The dual-axes confocal (DAC) architecture overcomes limitations of the conventional single-axis confocal (SAC) architecture to allow for miniaturization with high resolution. A microelectromechanical systems (MEMS) scanner is the central imaging component that is key in miniaturization of the DAC architecture. The design, fabrication, and characterization of the two-dimensional (2-D) MEMS scanner are presented. The gimbaled MEMS scanner is fabricated on a double silicon-on-insulator (SOI) wafer and is actuated by self-aligned vertical electrostatic combdrives. The imaging performance of the MEMS scanner in a DAC configuration is shown in a breadboard microscope setup, where reflectance and fluorescence imaging is demonstrated. Then, the MEMS scanner is integrated into a miniature DAC microscope. The whole imaging system is integrated into a portable unit for research in small animal models of human biology and disease. In vivo 3-D imaging is demonstrated on mouse skin models showing gene transfer and siRNA silencing. The siRNA silencing process is sequentially imaged in one mouse over time.

Expression of DNA repair genes in burned skin exposed to low-level red laser.

PubMed

Trajano, Eduardo Tavares Lima; Mencalha, Andre Luiz; Monte-Alto-Costa, Andréa; Pôrto, Luís Cristóvão; de Souza da Fonseca, Adenilson

2014-11-01

Although red laser lights lie in the region of non-ionizing radiations in the electromagnetic spectrum, there are doubts whether absorption of these radiations causes lesions in the DNA molecule. Our aim was to investigate the expression of the genes involved with base excision and nucleotide excision repair pathways in skin tissue submitted to burn injury and exposed to low-level red laser. Wistar rats were divided as follows: control group-rats burned and not irradiated, laser group-rats burned and irradiated 1 day after injury for five consecutive days, and later laser group-rats injured and treated 4 days after injury for five consecutive days. Irradiation was performed according to a clinical protocol (20 J/cm(2), 100 mW, continuous wave emission mode). The animals were sacrificed on day 10, and scarred tissue samples were withdrawn for total RNA extraction, complementary DNA (cDNA) synthesis, and evaluation of gene expression by quantitative polymerase chain reaction. Low-level red laser exposure (1) reduces the expression of APE1 messenger (mRNA), (2) increases the expression of OGG1 mRNA, (3) reduces the expression of XPC mRNA, and (4) increases the expression of XPA mRNA both in laser and later laser groups. Red laser exposure at therapeutic fluences alters the expression of genes related to base excision and nucleotide excision pathways of DNA repair during wound healing of burned skin.

Combined effects of cotyledon excision and nursery fertilization on root growth, nutrient status and outplanting performance of Quercus variabilis container seedlings

PubMed Central

Shi, Wenhui; Bloomberg, Mark; Li, Guolei; Su, Shuchai; Jia, Liming

2017-01-01

Artificial excision of the distal part of acorns in order to promote germination is well researched in oak seedling cultivation studies. However, studies of combined effects of cotyledon excision and nursery fertilization on container seedlings are lacking, especially for seedling root growth and outplanting performance. This study aimed to explore the main effects of cotyledon excision on Quercus variabilis seedling emergence characteristics and demonstrated the combined effects of cotyledon excision and nursery fertilization on seedling quality to improve Quercus variabilis seedling outplanting performance. Four cotyledon excision treatments and two classes of nursery fertilization were implemented. Seedling emergence was noted every week after sowing. Seedling dry mass, morphology, and nutrient status were assessed at the end of the nursery season. After the first outplanting season, the aforementioned measurements along with seedling survival were determined once again. The results showed that cotyledon excision generally induced greater and more rapid seedling emergence, but did not affect shoot emergence synchronicity. The highest total emergence and emergence rate occurred with Intermediate excision (1/2 of the distal end of acorn was excised). Effects of nutrient loss due to cotyledon excision on seedling quality and outplanting performance were somewhat compensated by nursery fertilization. Nursery fertilization promoted dry mass increment (the net increment from T0 to T2 for dry mass) for excised seedlings after outplanting, resulting in better performance for Slight (1/3 of the distal end of acorn was excised) and Intermediate excision treatments in the field. Thus we conclude Intermediate excision combined with reasonable nursery fertilization can be recommended for production of nursery grown seedlings for afforestation. PMID:28545103

Combined effects of cotyledon excision and nursery fertilization on root growth, nutrient status and outplanting performance of Quercus variabilis container seedlings.

PubMed

Shi, Wenhui; Bloomberg, Mark; Li, Guolei; Su, Shuchai; Jia, Liming

2017-01-01

Artificial excision of the distal part of acorns in order to promote germination is well researched in oak seedling cultivation studies. However, studies of combined effects of cotyledon excision and nursery fertilization on container seedlings are lacking, especially for seedling root growth and outplanting performance. This study aimed to explore the main effects of cotyledon excision on Quercus variabilis seedling emergence characteristics and demonstrated the combined effects of cotyledon excision and nursery fertilization on seedling quality to improve Quercus variabilis seedling outplanting performance. Four cotyledon excision treatments and two classes of nursery fertilization were implemented. Seedling emergence was noted every week after sowing. Seedling dry mass, morphology, and nutrient status were assessed at the end of the nursery season. After the first outplanting season, the aforementioned measurements along with seedling survival were determined once again. The results showed that cotyledon excision generally induced greater and more rapid seedling emergence, but did not affect shoot emergence synchronicity. The highest total emergence and emergence rate occurred with Intermediate excision (1/2 of the distal end of acorn was excised). Effects of nutrient loss due to cotyledon excision on seedling quality and outplanting performance were somewhat compensated by nursery fertilization. Nursery fertilization promoted dry mass increment (the net increment from T0 to T2 for dry mass) for excised seedlings after outplanting, resulting in better performance for Slight (1/3 of the distal end of acorn was excised) and Intermediate excision treatments in the field. Thus we conclude Intermediate excision combined with reasonable nursery fertilization can be recommended for production of nursery grown seedlings for afforestation.

Experience of treatment of patients with granulomatous lobular mastitis.

PubMed

Hur, Sung Mo; Cho, Dong Hui; Lee, Se Kyung; Choi, Min-Young; Bae, Soo Youn; Koo, Min Young; Kim, Sangmin; Choe, Jun-Ho; Kim, Jung-Han; Kim, Jee Soo; Nam, Seok-Jin; Yang, Jung-Hyun; Lee, Jeong Eon

2013-07-01

To present the author's experience with various treatment methods of granulomatous lobular mastitis (GLM) and to determine effective treatment methods of GLM. Fifty patients who were diagnosed with GLM were classified into five groups based on the initial treatment methods they underwent, which included observation (n = 8), antibiotics (n = 3), steroid (n = 13), drainage (n = 14), and surgical excision (n = 12). The treatment processes in each group were examined and their clinical characteristics, treatment processes, and results were analyzed respectively. Success rates with each initial treatment were observation, 87.5%; antibiotics, 33.3%; steroids, 30.8%; drainage, 28.6%; and surgical excision, 91.7%. In most cases of observation, the lesions were small and the symptoms were mild. A total of 23 patients underwent surgical excision during treatment. Surgical excision showed particularly fast recovery, high success rate (90.3%) and low recurrence rate (8.7%). The clinical course of GLM is complex and the outcome of each treatment type are variable. Surgery may play an important role when a lesion is determined to be mass-forming or appears localized as an abscess pocket during breast examination or imaging study.

The Effects of Postoperative Intralesional Corticosteroids in the Prevention of Recurrent Earlobe Keloids: A Multispecialty Retrospective Review.

PubMed

Gold, Daniel A; Sheinin, Renee; Jacobsen, Gordon; Jones, Lamont R; Ozog, David M

2018-06-01

Effective treatment of keloids is challenging because the recurrence rate after surgical excision is high. Data on the best treatment practices are lacking. To investigate the recurrence rate after surgical excision of earlobe keloids based on a postoperative intralesional corticosteroid injection protocol. Retrospective chart review was performed from January 1, 2005, to March 31, 2016, of patients who had excision of ear keloids within the departments of dermatology, otorhinolaryngology, and plastic surgery. The number of postoperative injections was recorded, recurrence was reported by the patient, and the efficacy of an injection protocol was evaluated. There were 277 charts reviewed. Appropriate data were available for 184 patients. A statistically significant difference was found with recurrence associated with a lower number of injections (p < .001). Keloids were more likely to recur if they were not treated with a planned serial injection protocol (p < .001) or if they were treated outside the department of dermatology (p < .001). Intralesional corticosteroid injection after surgical excision of earlobe keloids statistically minimizes the risk of recurrence.

Comparison of Three Surgical Methods in Treatment of Patients with Pilonidal Sinus: Modified Excision and Repair/Wide Excision/Wide Excision and Flap in RASOUL, OMID and SADR Hospitals( 2004-2007).

PubMed

Hosseini, Mostafa; Heidari, Afshin; Jafarnejad, Babak

2013-10-01

This study is a comparison between three methods that are frequently used for the surgical treatment of pilonidal disease all over the world: modified excision and repair, wide excision and secondary repair, and wide excision and flap. The first technique is done by our group for the first time, and has not been described previously in the literature. This is an interventional study performed at Omid, Sadr, and Rasoul Akram hospitals on patients who had undergone operation because of pilonidal sinus disease and met the inclusion criteria between 2004 and 2007. Exclusion criteria were (1) acute pilonidal sinus diseases, (2) history of pilonidal sinus surgery, (3) history of systemic diseases (DM, malignancy, etc.), and (4) pilonidal abscess. Essential information was extracted from complete medical archives. Any data not available in files or during follow-up visits (all patients supposed to be followed at least for 1 year) were gathered by a telephone interview. A total of 194 patients met the criteria and had complete archived files. Longer duration of hospital stay was found in the "wide excision and closing with flap" method comparing with two other methods (P < 0.05). Length of incapacity for work was not different between the "wide excision and modified repair" and "wide excision" (P > 0.5) methods, but longer for "wide excision and flap" in comparison with two others (P < 0.05). Healing time was significantly longer in the "wide excision" method in comparison with two other methods (P < 0.05). However, "wide excision and modified repair" method had the least healing time between all above techniques, except for length of leaving the office. All the three recurrences (1.5 %) occurred in the wide excision and flap method (P < 0.05). The frequency of postoperative complications was 2 (3.3 %) in wide excision and modified repair, 15 (18.5 %) in wide excision, and 17 (32.7 %) in wide excision and flap closure; these differences in complications were statistically significant (P < 0.05). Our results show that the wide excision and modified repair technique, which has been described for the first time, is an acceptable method due to a low recurrence rate and better wound outcomes comparing with wide excision alone and wide excision and flap techniques for the surgical treatment of pilonidal sinus disease.

The disordered C-terminal domain of human DNA glycosylase NEIL1 contributes to its stability via intramolecular interactions.

PubMed

Hegde, Muralidhar L; Tsutakawa, Susan E; Hegde, Pavana M; Holthauzen, Luis Marcelo F; Li, Jing; Oezguen, Numan; Hilser, Vincent J; Tainer, John A; Mitra, Sankar

2013-07-10

NEIL1 [Nei (endonuclease VIII)-like protein 1], one of the five mammalian DNA glycosylases that excise oxidized DNA base lesions in the human genome to initiate base excision repair, contains an intrinsically disordered C-terminal domain (CTD; ~100 residues), not conserved in its Escherichia coli prototype Nei. Although dispensable for NEIL1's lesion excision and AP lyase activities, this segment is required for efficient in vivo enzymatic activity and may provide an interaction interface for many of NEIL1's interactions with other base excision repair proteins. Here, we show that the CTD interacts with the folded domain in native NEIL1 containing 389 residues. The CTD is poised for local folding in an ordered structure that is induced in the purified fragment by osmolytes. Furthermore, deletion of the disordered tail lacking both Tyr and Trp residues causes a red shift in NEIL1's intrinsic Trp-specific fluorescence, indicating a more solvent-exposed environment for the Trp residues in the truncated protein, which also exhibits reduced stability compared to the native enzyme. These observations are consistent with stabilization of the native NEIL1 structure via intramolecular, mostly electrostatic, interactions that were disrupted by mutating a positively charged (Lys-rich) cluster of residues (amino acids 355-360) near the C-terminus. Small-angle X-ray scattering (SAXS) analysis confirms the flexibility and dynamic nature of NEIL1's CTD, a feature that may be critical to providing specificity for NEIL1's multiple, functional interactions. Copyright © 2013 Elsevier Ltd. All rights reserved.

Cross-talk between ATP-regulated K+ channels and Na+ transport via cellular metabolism in frog skin principal cells.

PubMed Central

Urbach, V; Van Kerkhove, E; Maguire, D; Harvey, B J

1996-01-01

Isolated frog skin epithelium, mounted in an Ussing chamber and bathed in standard NaCl Ringer solution, recycles K+ across the basolateral membrane of principal cells through an inward-rectifier K+ channel (Kir) operating in parallel with a Na+-K+-ATPase pump. Here we report on the metabolic control of the Kir channel using patch clamping, short-circuit current measurement and enzymatic determination of cellular (ATP (ATPi). 2. The constitutively active Kir channel in the basolateral membrane has the characteristics of an ATP-regulated K+ channel and is now classed as a KATP channel. In excised inside-out patches the open probability (Po) of KATP channels was reduced by ATPi with half-maximum inhibition at an ATPi concentration of 50 microM. 3. ATPi measured (under normal Na+ transport conditions) with luciferin-luciferase was 1.50 +/- 0.23 mM (mean +/- S.E.M.; range, 0.4-3.3 mM n = 11). Thus the KATP channel would be expected to be inactive in intact cells if ATPi was the sole regulator of channel activity. KATP channels which were inactivated by 1 mM ATPi in excised patches could be reactivated by addition of 100 microM ADP on the cytosolic side. When added alone, ADP blocks this channel with half-maximal inhibition at [ADPi] > 5 mM. 4. Sulphonylureas inhibit single KATP channels in cell-attached patches as well as the total basolateral K+ current measured in frog skin epithelia perforated with nystatin on the apical side. 5. Na+-K+-ATPase activity is a major determinant of cytosolic ATP. Blocking the pump activity with ouabain produced a time-dependent increase in ATPi and reduced the open probability of KATP channels in cell-attached membranes. 6. We conclude that the ratio of ATP/ADP is an important metabolic coupling factor between the rate of Na+-K+ pumping and K+ recycling. Images Figure 9 PMID:9011625

Lymphocyte trafficking and HIV infection of human lymphoid tissue in a rotating wall vessel bioreactor

NASA Technical Reports Server (NTRS)

Margolis, L. B.; Fitzgerald, W.; Glushakova, S.; Hatfill, S.; Amichay, N.; Baibakov, B.; Zimmerberg, J.

1997-01-01

The pathogenesis of HIV infection involves a complex interplay between both the infected and noninfected cells of human lymphoid tissue, the release of free viral particles, the de novo infection of cells, and the recirculatory trafficking of peripheral blood lymphocytes. To develop an in vitro model for studying these various aspects of HIV pathogenesis we have utilized blocks of surgically excised human tonsils and a rotating wall vessel (RWV) cell culture system. Here we show that (1) fragments of the surgically excised human lymphoid tissue remain viable and retain their gross cytoarchitecture for at least 3 weeks when cultured in the RWV system; (2) such lymphoid tissue gradually shows a loss of both T and B cells to the surrounding growth medium; however, this cellular migration is reversible as demonstrated by repopulation of the tissue by labeled cells from the growth medium; (3) this cellular migration may be partially or completely inhibited by embedding the blocks of lymphoid tissue in either a collagen or agarose gel matrix; these embedded tissue blocks retain most of the basic elements of a normal lymphoid cytoarchitecture; and (4) both embedded and nonembedded RWV-cultured blocks of human lymphoid tissue are capable of productive infection by HIV-1 of at least three various strains of different tropism and phenotype, as shown by an increase in both p24 antigen levels and free virus in the culture medium, and by the demonstration of HIV-1 RNA-positive cells inside the tissue identified by in situ hybridization. It is therefore reasonable to suggest that gel-embedded and nonembedded blocks of human lymphoid tissue, cocultured with a suspension of tonsillar lymphocytes in an RWV culture system, constitute a useful model for simulating normal lymphocyte recirculatory traffic and provide a new tool for testing the various aspects of HIV pathogenesis.

Dynamic maps of UV damage formation and repair for the human genome

PubMed Central

Hu, Jinchuan; Adebali, Ogun; Adar, Sheera; Sancar, Aziz

2017-01-01

Formation and repair of UV-induced DNA damage in human cells are affected by cellular context. To study factors influencing damage formation and repair genome-wide, we developed a highly sensitive single-nucleotide resolution damage mapping method [high-sensitivity damage sequencing (HS–Damage-seq)]. Damage maps of both cyclobutane pyrimidine dimers (CPDs) and pyrimidine-pyrimidone (6-4) photoproducts [(6-4)PPs] from UV-irradiated cellular and naked DNA revealed that the effect of transcription factor binding on bulky adducts formation varies, depending on the specific transcription factor, damage type, and strand. We also generated time-resolved UV damage maps of both CPDs and (6-4)PPs by HS–Damage-seq and compared them to the complementary repair maps of the human genome obtained by excision repair sequencing to gain insight into factors that affect UV-induced DNA damage and repair and ultimately UV carcinogenesis. The combination of the two methods revealed that, whereas UV-induced damage is virtually uniform throughout the genome, repair is affected by chromatin states, transcription, and transcription factor binding, in a manner that depends on the type of DNA damage. PMID:28607063

Ultrahigh resolution optical coherence elastography using a Bessel beam for extended depth of field

NASA Astrophysics Data System (ADS)

Curatolo, Andrea; Villiger, Martin; Lorenser, Dirk; Wijesinghe, Philip; Fritz, Alexander; Kennedy, Brendan F.; Sampson, David D.

2016-03-01

Visualizing stiffness within the local tissue environment at the cellular and sub-cellular level promises to provide insight into the genesis and progression of disease. In this paper, we propose ultrahigh-resolution optical coherence elastography, and demonstrate three-dimensional imaging of local axial strain of tissues undergoing compressive loading. The technique employs a dual-arm extended focus optical coherence microscope to measure tissue displacement under compression. The system uses a broad bandwidth supercontinuum source for ultrahigh axial resolution, Bessel beam illumination and Gaussian beam detection, maintaining sub-2 μm transverse resolution over nearly 100 μm depth of field, and spectral-domain detection allowing high displacement sensitivity. The system produces strain elastograms with a record resolution (x,y,z) of 2×2×15 μm. We benchmark the advances in terms of resolution and strain sensitivity by imaging a suitable inclusion phantom. We also demonstrate this performance on freshly excised mouse aorta and reveal the mechanical heterogeneity of vascular smooth muscle cells and elastin sheets, otherwise unresolved in a typical, lower resolution optical coherence elastography system.

Dynamic maps of UV damage formation and repair for the human genome.

PubMed

Hu, Jinchuan; Adebali, Ogun; Adar, Sheera; Sancar, Aziz

2017-06-27

Formation and repair of UV-induced DNA damage in human cells are affected by cellular context. To study factors influencing damage formation and repair genome-wide, we developed a highly sensitive single-nucleotide resolution damage mapping method [high-sensitivity damage sequencing (HS-Damage-seq)]. Damage maps of both cyclobutane pyrimidine dimers (CPDs) and pyrimidine-pyrimidone (6-4) photoproducts [(6-4)PPs] from UV-irradiated cellular and naked DNA revealed that the effect of transcription factor binding on bulky adducts formation varies, depending on the specific transcription factor, damage type, and strand. We also generated time-resolved UV damage maps of both CPDs and (6-4)PPs by HS-Damage-seq and compared them to the complementary repair maps of the human genome obtained by excision repair sequencing to gain insight into factors that affect UV-induced DNA damage and repair and ultimately UV carcinogenesis. The combination of the two methods revealed that, whereas UV-induced damage is virtually uniform throughout the genome, repair is affected by chromatin states, transcription, and transcription factor binding, in a manner that depends on the type of DNA damage.

Whole-body tissue stabilization and selective extractions via tissue-hydrogel hybrids for high-resolution intact circuit mapping and phenotyping

PubMed Central

Treweek, Jennifer B; Deverman, Benjamin E; Greenbaum, Alon; Lignell, Antti; Xiao, Cheng; Cai, Long; Ladinsky, Mark S; Bjorkman, Pamela J; Fowlkes, Charless C; Gradinaru, Viviana

2016-01-01

To facilitate fine-scale phenotyping of whole specimens, we describe here a set of tissue fixation-embedding, detergent-clearing and staining protocols that can be used to transform excised organs and whole organisms into optically transparent samples within 1–2 weeks without compromising their cellular architecture or endogenous fluorescence. PACT (passive CLARITY technique) and PARS (perfusion-assisted agent release in situ) use tissue-hydrogel hybrids to stabilize tissue biomolecules during selective lipid extraction, resulting in enhanced clearing efficiency and sample integrity. Furthermore, the macromolecule permeability of PACT- and PARS-processed tissue hybrids supports the diffusion of immunolabels throughout intact tissue, whereas RIMS (refractive index matching solution) grants high-resolution imaging at depth by further reducing light scattering in cleared and uncleared samples alike. These methods are adaptable to difficult-to-image tissues, such as bone (PACT-deCAL), and to magnified single-cell visualization (ePACT). Together, these protocols and solutions enable phenotyping of subcellular components and tracing cellular connectivity in intact biological networks. PMID:26492141

The substrate binding interface of alkylpurine DNA glycosylase AlkD.

PubMed

Mullins, Elwood A; Rubinson, Emily H; Eichman, Brandt F

2014-01-01

Tandem helical repeats have emerged as an important DNA binding architecture. DNA glycosylase AlkD, which excises N3- and N7-alkylated nucleobases, uses repeating helical motifs to bind duplex DNA and to selectively pause at non-Watson-Crick base pairs. Remodeling of the DNA backbone promotes nucleotide flipping of the lesion and the complementary base into the solvent and toward the protein surface, respectively. The important features of this new DNA binding architecture that allow AlkD to distinguish between damaged and normal DNA without contacting the lesion are poorly understood. Here, we show through extensive mutational analysis that DNA binding and N3-methyladenine (3mA) and N7-methylguanine (7mG) excision are dependent upon each residue lining the DNA binding interface. Disrupting electrostatic or hydrophobic interactions with the DNA backbone substantially reduced binding affinity and catalytic activity. These results demonstrate that residues seemingly only involved in general DNA binding are important for catalytic activity and imply that base excision is driven by binding energy provided by the entire substrate interface of this novel DNA binding architecture. Copyright © 2013 Elsevier B.V. All rights reserved.

26 CFR 55.4981-2 - Imposition of excise tax with respect to certain undistributed income of real estate investment...

Code of Federal Regulations, 2011 CFR

2011-04-01

... certain undistributed income of real estate investment trusts; calendar years beginning after December 31... (CONTINUED) MISCELLANEOUS EXCISE TAXES (CONTINUED) EXCISE TAX ON REAL ESTATE INVESTMENT TRUSTS AND REGULATED INVESTMENT COMPANIES Excise Tax on Real Estate Investment Trusts § 55.4981-2 Imposition of excise tax with...

26 CFR 55.4981-1 - Imposition of excise tax on certain real estate investment trust taxable income not distributed...

Code of Federal Regulations, 2014 CFR

2014-04-01

... TREASURY (CONTINUED) MISCELLANEOUS EXCISE TAXES (CONTINUED) EXCISE TAX ON REAL ESTATE INVESTMENT TRUSTS AND REGULATED INVESTMENT COMPANIES Excise Tax on Real Estate Investment Trusts § 55.4981-1 Imposition of excise tax on certain real estate investment trust taxable income not distributed during the taxable year...

26 CFR 55.4981-1 - Imposition of excise tax on certain real estate investment trust taxable income not distributed...

Code of Federal Regulations, 2011 CFR

2011-04-01

... TREASURY (CONTINUED) MISCELLANEOUS EXCISE TAXES (CONTINUED) EXCISE TAX ON REAL ESTATE INVESTMENT TRUSTS AND REGULATED INVESTMENT COMPANIES Excise Tax on Real Estate Investment Trusts § 55.4981-1 Imposition of excise tax on certain real estate investment trust taxable income not distributed during the taxable year...

26 CFR 55.4981-2 - Imposition of excise tax with respect to certain undistributed income of real estate investment...

Code of Federal Regulations, 2014 CFR

2014-04-01

... certain undistributed income of real estate investment trusts; calendar years beginning after December 31... (CONTINUED) MISCELLANEOUS EXCISE TAXES (CONTINUED) EXCISE TAX ON REAL ESTATE INVESTMENT TRUSTS AND REGULATED INVESTMENT COMPANIES Excise Tax on Real Estate Investment Trusts § 55.4981-2 Imposition of excise tax with...

26 CFR 55.4981-1 - Imposition of excise tax on certain real estate investment trust taxable income not distributed...

Code of Federal Regulations, 2010 CFR

2010-04-01

... TREASURY (CONTINUED) MISCELLANEOUS EXCISE TAXES (CONTINUED) EXCISE TAX ON REAL ESTATE INVESTMENT TRUSTS AND REGULATED INVESTMENT COMPANIES Excise Tax on Real Estate Investment Trusts § 55.4981-1 Imposition of excise tax on certain real estate investment trust taxable income not distributed during the taxable year...

26 CFR 55.4981-2 - Imposition of excise tax with respect to certain undistributed income of real estate investment...

Code of Federal Regulations, 2012 CFR

2012-04-01

... certain undistributed income of real estate investment trusts; calendar years beginning after December 31... (CONTINUED) MISCELLANEOUS EXCISE TAXES (CONTINUED) EXCISE TAX ON REAL ESTATE INVESTMENT TRUSTS AND REGULATED INVESTMENT COMPANIES Excise Tax on Real Estate Investment Trusts § 55.4981-2 Imposition of excise tax with...

26 CFR 55.4981-2 - Imposition of excise tax with respect to certain undistributed income of real estate investment...

Code of Federal Regulations, 2010 CFR

2010-04-01

... certain undistributed income of real estate investment trusts; calendar years beginning after December 31... (CONTINUED) MISCELLANEOUS EXCISE TAXES (CONTINUED) EXCISE TAX ON REAL ESTATE INVESTMENT TRUSTS AND REGULATED INVESTMENT COMPANIES Excise Tax on Real Estate Investment Trusts § 55.4981-2 Imposition of excise tax with...

26 CFR 55.4981-1 - Imposition of excise tax on certain real estate investment trust taxable income not distributed...

Code of Federal Regulations, 2013 CFR

2013-04-01

... TREASURY (CONTINUED) MISCELLANEOUS EXCISE TAXES (CONTINUED) EXCISE TAX ON REAL ESTATE INVESTMENT TRUSTS AND REGULATED INVESTMENT COMPANIES Excise Tax on Real Estate Investment Trusts § 55.4981-1 Imposition of excise tax on certain real estate investment trust taxable income not distributed during the taxable year...

26 CFR 55.4981-2 - Imposition of excise tax with respect to certain undistributed income of real estate investment...

Code of Federal Regulations, 2013 CFR

2013-04-01

... certain undistributed income of real estate investment trusts; calendar years beginning after December 31... (CONTINUED) MISCELLANEOUS EXCISE TAXES (CONTINUED) EXCISE TAX ON REAL ESTATE INVESTMENT TRUSTS AND REGULATED INVESTMENT COMPANIES Excise Tax on Real Estate Investment Trusts § 55.4981-2 Imposition of excise tax with...

26 CFR 55.4981-1 - Imposition of excise tax on certain real estate investment trust taxable income not distributed...

Code of Federal Regulations, 2012 CFR

2012-04-01

... TREASURY (CONTINUED) MISCELLANEOUS EXCISE TAXES (CONTINUED) EXCISE TAX ON REAL ESTATE INVESTMENT TRUSTS AND REGULATED INVESTMENT COMPANIES Excise Tax on Real Estate Investment Trusts § 55.4981-1 Imposition of excise tax on certain real estate investment trust taxable income not distributed during the taxable year...

29 CFR 779.262 - Excise taxes at the retail level.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Coverage Excise Taxes § 779.262 Excise taxes at the retail level. (a) Federal excise taxes are imposed at.... Such excise taxes are levied at the retail level on any liquid fuel sold for use, or used in a diesel... levied at the retail level, and thus excludable when separately stated, depends, of course, upon the law...

Evidence-Based Medicine: Options for Dupuytren's Contracture: Incise, Excise, and Dissolve.

PubMed

Denkler, Keith A; Vaughn, Carolyn J; Dolan, Estelle L; Hansen, Scott L

2017-01-01

After studying this article, the participant should be able to: 1. Understand updates in the basic science, epidemiology, and treatment of Dupuytren's disease. 2. Understand treatment with needle aponeurotomy, collagenase, and fasciectomy. 3. Understand advanced needle techniques for Dupuytren's contracture. 4. Understand the safety and effectiveness of a new treatment, collagenase. The literature on Dupuytren's disease encompasses many specialties. Its treatment is generally by perforating, excising, or dissolving the affected tissues. This article reviews the changing understanding of this disease and treatment options.

26 CFR 54.4979-1 - Excise tax on certain excess contributions and excess aggregate contributions.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 17 2010-04-01 2010-04-01 false Excise tax on certain excess contributions and excess aggregate contributions. 54.4979-1 Section 54.4979-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) MISCELLANEOUS EXCISE TAXES (CONTINUED) PENSION EXCISE TAXES § 54.4979-1 Excise tax on certain excess...

29 CFR 779.262 - Excise taxes at the retail level.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 29 Labor 3 2011-07-01 2011-07-01 false Excise taxes at the retail level. 779.262 Section 779.262... Coverage Excise Taxes § 779.262 Excise taxes at the retail level. (a) Federal excise taxes are imposed at the retail level on highway vehicle fuels other than gasoline under the provisions of 26 U.S.C. 4041...

29 CFR 779.262 - Excise taxes at the retail level.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 29 Labor 3 2013-07-01 2013-07-01 false Excise taxes at the retail level. 779.262 Section 779.262... Coverage Excise Taxes § 779.262 Excise taxes at the retail level. (a) Federal excise taxes are imposed at the retail level on highway vehicle fuels other than gasoline under the provisions of 26 U.S.C. 4041...

29 CFR 779.262 - Excise taxes at the retail level.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 29 Labor 3 2012-07-01 2012-07-01 false Excise taxes at the retail level. 779.262 Section 779.262... Coverage Excise Taxes § 779.262 Excise taxes at the retail level. (a) Federal excise taxes are imposed at the retail level on highway vehicle fuels other than gasoline under the provisions of 26 U.S.C. 4041...

29 CFR 779.262 - Excise taxes at the retail level.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 29 Labor 3 2014-07-01 2014-07-01 false Excise taxes at the retail level. 779.262 Section 779.262... Coverage Excise Taxes § 779.262 Excise taxes at the retail level. (a) Federal excise taxes are imposed at the retail level on highway vehicle fuels other than gasoline under the provisions of 26 U.S.C. 4041...

Predictors of Residual Disease after Unplanned Excision of Soft Tissue Sarcomas

PubMed Central

Gingrich, Alicia A.; Elias, Alexandra; Michael Lee, Chia-Yuan; Nakache, Yves-Paul N.; Li, Chin-Shang; Shah, Dhruvil R.; Boutin, Robert D.; Canter, Robert J.

2016-01-01

Background Unplanned excision of soft tissue sarcomas (STS) is an important quality of care issue given the morbidity related to tumor bed excision. Since not all patients harbor residual disease at the time of re-excision, we sought to determine predictors of residual STS following unplanned excision. Methods We identified 76 patients from a prospective database (1/1/2008 – 9/30/2014) who received a diagnosis of primary STS following unplanned excision on the trunk or extremities. We used univariable and multivariable analyses to evaluate predictors of residual STS as the primary endpoint. We calculated the sensitivity/specificity and accuracy of interval magnetic resonance imaging (MRI) to predict residual sarcoma at re-excision. Results Mean age was 52 years, and 63.2% were male. 50% had fragmented unplanned excision. Among patients undergoing re-excision, residual STS was identified in 70%. On univariable analysis, MRI showing gross disease and fragmented excision were significant predictors of residual STS (OR 10.59, 95% CI 2.14–52.49, P=0.004 and OR 3.61, 95% CI 1.09–11.94, P=0.035, respectively). On multivariable analysis, tumor size predicted distant recurrence and overall survival. When we combined equivocal and positive MRI, the sensitivity and specificity of MRI for predicting residual STS were 86.7% (95% CI 73.2–95.0%) and 57.9% (95% CI 33.5–79.8%), with an overall accuracy of 78.1% (95% CI 66.0–87.5%). Conclusions 70% of patients undergoing repeat excision after unplanned excision of STS harbor residual sarcoma. Although interval MRI and fragmented excision appear to be the most significant predictors of residual STS, the accuracy of MRI remains modest, especially given the incidence of equivocal MRI. PMID:27993214

Assessment of ankle and hindfoot stability and joint pressures using a human cadaveric model of a large lateral talar process excision: a biomechanical study.

PubMed

Sands, Andrew; White, Charles; Blankstein, Michael; Zderic, Ivan; Wahl, Dieter; Ernst, Manuela; Windolf, Markus; Hagen, Jennifer E; Richards, R Geoff; Stoffel, Karl; Gueorguiev, Boyko

2015-03-01

Lateral talar process fragment excision may be followed by hindfoot instability and altered biomechanics. There is controversy regarding the ideal fragment size for internal fixation versus excision and a concern that excision of a large fragment may lead to significant instability. The aim of this study was to assess the effect of a simulated large lateral talar process excision on ankle and subtalar joint stability.A custom-made seesaw rig was designed to apply inversion/eversion stress loading on 7 fresh-frozen human cadaveric lower legs and investigate them in pre-excision, 5 cm and 10 cm lateral talar process fragment excision states. Anteroposterior radiographs were taken to assess ankle and subtalar joint tilt and calculate angular change from neutral hindfoot alignment to 10-kg forced inversion/eversion. Ankle joint pressures and contact areas were measured under 30-kg axial load in neutral hindfoot alignment.In comparison to the pre-excision state, no significantly different mediolateral angular change was observed in the subtalar joint after 5 and 10 cm lateral talar process fragment excision in inversion and eversion. With respect to the ankle joint, 10-cm fragment excision produced significantly bigger inversion tibiotalar tilt compared with the pre-excision state, P = .04. No significant change of the ankle joint pressure and contact area was detected after 5 and 10-cm excision in comparison with the pre-excison state.An excision of up to 10 cm of the lateral talar process does not cause a significant instability at the level of the subtalar joint but might be a destabilizing factor at the ankle joint under inversion stress. The latter could be related to extensive soft tissue dissection required for resection.

Clinical and Radiologic Follow-up Study for Biopsy Diagnosis of Radial Scar/Radial Sclerosing Lesion without Other Atypia.

PubMed

Kalife, Elizabeth Tágide; Lourenco, Ana P; Baird, Grayson L; Wang, Yihong

2016-11-01

To determine the incidence of malignancy for radial scars (RS)/radial sclerosing lesions (RSL) without associated atypia or malignancy identified at needle biopsy. Retrospective review of the pathology data base from January 2004 to July 2013 yielded 100 needle biopsies diagnosed as RS/RSL without associated atypia/malignancy. The RS/RSL was considered "incidental" if the target was calcifications and "targeted" if imaging revealed a mass, architectural distortion, or suspicious magnetic resonance imaging enhancement. The electronic medical record was used to identify surgical pathology, follow-up imaging, and clinical course; all pathology slides and imaging were reviewed by a board-certified pathologist and radiologist, respectively. Patient age, laterality, RS/RSL size, microcalcifications, and associated benign lesions were recorded. Among 100 cases, 54 were "incidental" and 46 were "targeted." In the incidental group, 14 underwent excision, 30 had imaging follow-up, and 10 were lost to follow-up. In the targeted group, 27 underwent excision, 11 had imaging follow-up, and 8 were lost to follow-up. Atypia was identified in four excisions: three from the incidental group and one from the targeted group. Among these, three had negative imaging follow-up (mean 45 months; range 15-60 months); the fourth patient (one of the incidental group) underwent excision alone. One of the 27 "targeted" patients who underwent excision developed ductal carcinoma in situ of the contralateral breast at 96 months. There have been no ipsilateral malignancies. We found no evidence of associated malignancy at excision for either incidental or targeted biopsies of RS/RSL without atypia. Our study suggests that close imaging follow-up is adequate for patients with RS/RSL without associated atypia/malignancy on needle biopsy. © 2016 Wiley Periodicals, Inc.

Outcome after surgical or conservative management of cerebral cavernous malformations.

PubMed

Moultrie, Fiona; Horne, Margaret A; Josephson, Colin B; Hall, Julie M; Counsell, Carl E; Bhattacharya, Jo J; Papanastassiou, Vakis; Sellar, Robin J; Warlow, Charles P; Murray, Gordon D; Al-Shahi Salman, Rustam

2014-08-12

There have been few comparative studies of microsurgical excision vs conservative management of cerebral cavernous malformations (CCM) and none of them has reliably demonstrated a statistically and clinically significant difference. We conducted a prospective, population-based study to identify and independently validate definite CCM diagnoses first made in 1999-2003 in Scottish adult residents. We used multiple sources of prospective follow-up to assess adults' dependence and to identify and independently validate outcome events. We used univariate and multivariable survival analyses to test the influence of CCM excision on outcome, adjusted for prognostic factors and baseline imbalances. Of 134 adults, 25 underwent CCM excision; these adults were younger (34 vs 43 years at diagnosis, p = 0.004) and more likely to present with symptomatic intracranial hemorrhage or focal neurologic deficit than adults managed conservatively (48% vs 26%; odds ratio 2.7, 95% confidence interval [CI] 1.1-6.5). During 5 years of follow-up, CCM excision was associated with a deterioration to an Oxford Handicap Scale score 2-6 sustained over at least 2 successive years (adjusted hazard ratio [HR] 2.2, 95% CI 1.1-4.3) and the occurrence of symptomatic intracranial hemorrhage or new focal neurologic deficit (adjusted HR 3.6, 95% CI 1.3-10.0). CCM excision was associated with worse outcomes over 5 years compared to conservative management. Long-term follow-up will determine whether this difference is sustained over patients' lifetimes. Meanwhile, a randomized controlled trial appears justified. This study provides Class III evidence that CCM excision worsens short-term disability scores and increases the risk of symptomatic intracranial hemorrhage and new focal neurologic deficits. © 2014 American Academy of Neurology.

UK national survey of management of breast lobular carcinoma in situ.

PubMed

Chester, R; Bokinni, O; Ahmed, I; Kasem, A

2015-11-01

There is no national standard treatment for patients with breast lobular carcinoma in situ (LCIS). Association of Breast Surgery guidelines for the management of breast cancer suggest that lesions containing LCIS should be excised for definitive diagnosis and recommend close surveillance after excision biopsy. The aim of this study was to form a picture of the current management of LCIS by UK breast surgeons. A questionnaire about the management of LCIS was sent to 490 UK breast surgeons. Of 490 questionnaires sent out, 173 (35%) were returned. When LCIS is present in a core biopsy, 61% of breast surgeons perform surgical excision, 22% would not excise but would continue follow-up and the remainder perform neither or set no clear management plan. Over half (54%) follow patients up with five years of annual mammography. If classic LCIS were found at the margins of wide local excision, 92% would not re-excise. Conversely, if pleomorphic LCIS were found, 71% would achieve clear margins. Respondents were split evenly regarding management of classic LCIS with a family history as 54% would not alter management whereas 43% would treat the disease more aggressively. Our survey has shown that in cases where LCIS is found at core biopsy, most surgeons follow Association of Breast Surgery guidance, obtaining further histological samples to exclude pleomorphic LCIS, ductal carcinoma in situ or invasive cancer, whereas others opt for annual surveillance and some discharge the patient. This study highlighted the huge variability in LCIS management, and the need for randomised controlled trials and input into national audits such as the Sloane Project to establish evidence-based national standard guidelines.

[Deep infiltrating endometriosis surgical management and pelvic nerves injury].

PubMed

Fermaut, M; Nyangoh Timoh, K; Lebacle, C; Moszkowicz, D; Benoit, G; Bessede, T

2016-05-01

Deep pelvic endometriosis surgery may need substantial excisions, which in turn expose to risks of injury to the pelvic nerves. To limit functional complications, nerve-sparing surgical techniques have been developed but should be adapted to the specific multifocal character of endometriotic lesions. The objective was to identify the anatomical areas where the pelvic nerves are most at risk of injury during endometriotic excisions. The Medline and Embase databases have been searched for available literature using the keywords "hypogastric nerve or hypogastric plexus [Mesh] or autonomic pathway [Mesh], anatomy, endometriosis, surgery [Mesh]". All relevant French and English publications, selected based on their available abstracts, have been reviewed. Five female adult fresh cadavers have been dissected to localize the key anatomical areas where the pelvic nerves are most at risk of injury. Six anatomical areas of high risk for pelvic nerves have been identified, analysed and described. Pelvic nerves can be damaged during the dissection of retrorectal space and the anterolateral rectal excision. Furthermore, before an uterosacral ligament excision, a parametrial excision, a colpectomy or a dissection of the vesico-uterine ligament, the hypogastric nerves, splanchnic nerves, inferior hypogastric plexus and its efferent pathways must be mapped out to avoid injury. The distance between the deep uterin vein and the pelvic splanchnic nerves were measured on four cadavers and varied from 2.5cm to 4cm. Six key anatomical pitfalls must be known in order to limit the functional complications of the endometriotic surgical excision. Applying nerve-sparing surgical techniques for endometriosis would lead to less urinary functional complications and a better short-term postoperative satisfaction. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Base Excision Repair

PubMed Central

Krokan, Hans E.; Bjørås, Magnar

2013-01-01

Base excision repair (BER) corrects DNA damage from oxidation, deamination and alkylation. Such base lesions cause little distortion to the DNA helix structure. BER is initiated by a DNA glycosylase that recognizes and removes the damaged base, leaving an abasic site that is further processed by short-patch repair or long-patch repair that largely uses different proteins to complete BER. At least 11 distinct mammalian DNA glycosylases are known, each recognizing a few related lesions, frequently with some overlap in specificities. Impressively, the damaged bases are rapidly identified in a vast excess of normal bases, without a supply of energy. BER protects against cancer, aging, and neurodegeneration and takes place both in nuclei and mitochondria. More recently, an important role of uracil-DNA glycosylase UNG2 in adaptive immunity was revealed. Furthermore, other DNA glycosylases may have important roles in epigenetics, thus expanding the repertoire of BER proteins. PMID:23545420

26 CFR 54.4979-0 - Excise tax on certain excess contributions and excess aggregate contributions; table of contents.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 17 2010-04-01 2010-04-01 false Excise tax on certain excess contributions and excess aggregate contributions; table of contents. 54.4979-0 Section 54.4979-0 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) MISCELLANEOUS EXCISE TAXES (CONTINUED) PENSION EXCISE TAXES § 54.4979-0 Excise tax on...

Metrics of Cellular and Vascular Infiltration of Human Acellular Dermal Matrix in Ventral Hernia Repairs

PubMed Central

Campbell, Kristin Turza; Burns, Nadja K.; Ensor, Joe; Butler, Charles E.

2012-01-01

Background Human acellular dermal matrix (HADM) is used for ventral hernia repair, as it resists infection and remodels via surrounding tissue. However, the tissue source and impact of basement membrane (BM) on cell and vessel infiltration have not been determined. We hypothesized that musculofascia would be the primary tissue source of cells and vessels infiltrating into HADM and the BM would inhibit infiltration. Methods Fifty-six guinea pigs underwent inlay HADM ventral hernia repair with the BM oriented toward or away from the peritoneum. At postoperative weeks 1, 2, or 4, repair sites were completely excised. Histologic and immunohistochemical analyses were performed to quantify cell and vessel density within repair-site zones, including interface (lateral, beneath musculofascia) and center (beneath subcutaneous fat) zones. Cell and vessel quantities were compared as functions of zone, BM orientation, and time. Results Cellular and vascular infiltration increased over time universally. The interface demonstrated greater mean cell density than the center (weeks 1 and 2, p=0.01, p<0.0001). Cell density was greater with the BM oriented toward the peritoneum at week 4 (p=0.02). The interface zone had greater mean vessel density than the center zone at week 4 (p<0.0001). Orienting the BM toward the peritoneum increased vessel density at week 4 (p=0.0004). Conclusion Cellular and vascular infiltration into HADM for ventral hernia repairs was greater from musculofascia than subcutaneous and the BM inhibited cellular and vascular. HADM should be placed adjacent to the best vascularizing tissue to improve fibrovascular incorporation. PMID:22456361

The Role of Transanal Surgery in the Management of T1 Rectal Cancers.

PubMed

Hassan, Imran; Wise, Paul E; Margolin, David A; Fleshman, James W

2015-09-01

The management of T1 rectal cancers is based on finding the balance between optimal oncologic outcomes and acceptable functional results for the patient. While radical resection involving a proctectomy is considered the most oncologically adequate option, its adverse effects on patient reported outcomes makes this a less than ideal choice in certain circumstances. While local excision can circumvent some of the adverse functional outcomes, its inadequacy in assessing metastatic lymph node disease and the subsequent negative impact of untreated positive lymph nodes on patient prognosis is a cause for concern. As a result, the therapeutic strategy has to be based on patient and disease-related factors in order to identify the best treatment choice that maximizes survival benefit and preserves health-related quality of life. After adequate preoperative staging work up, in selected patients with favorable pathological features, local excision can be considered. These cancers can be removed by transanal local excision or transanal endoscopic microsurgery, depending on the location of the cancer and expertise available. While perioperative morbidity is minimal, close postoperative follow-up is essential.

The therapeutic application of CRISPR/Cas9 technologies for HIV

PubMed Central

Saayman, Sheena; Ali, Stuart A.; Morris, Kevin V.; Weinberg, Marc S.

2015-01-01

Introduction The use of antiretroviral therapy (ART) has led to a significant decrease in morbidity and mortality in HIV-infected individuals. Nevertheless gene-based therapies represent a promising therapeutic paradigm for HIV-1, as they have the potential for sustained viral inhibition and reduced treatment interventions. One new method amendable to a gene-based therapy is the clustered regularly interspaced palindromic repeats (CRISPR)/Cas9 gene editing system. Areas covered CRISPR/Cas9 can be engineered to successfully modulate an array of disease-causing genetic elements. We discuss the diverse roles that CRISPR/Cas9 may play in targeting HIV and eradicating infection. The Cas9 nuclease coupled with one or more small guide RNAs (sgRNAs) can target the provirus to mediate excision of the integrated viral genome. Moreover, a modified nuclease deficient Cas9 fused to transcription activating domains may induce targeted activation of proviral gene expression allowing for the purging of the latent reservoirs. These technologies can also be exploited to target host dependency factors such as the co-receptor CCR5, thus preventing cellular entry of the virus. Expert opinion The diversity of the CRISPR/Cas9 technologies hold great promise for targeting different stages of the viral life cycle, and have the capacity for mediating an effective and sustained genetic therapy against HIV. PMID:25865334

Poly(ADP-ribose) Contributes to an Association between Poly(ADP-ribose) Polymerase-1 and Xeroderma Pigmentosum Complementation Group A in Nucleotide Excision Repair*

PubMed Central

King, Brenee S.; Cooper, Karen L.; Liu, Ke Jian; Hudson, Laurie G.

2012-01-01

Exposure to ultraviolet radiation (UVR) promotes the formation of UVR-induced, DNA helix distorting photolesions such as (6-4) pyrimidine-pyrimidone photoproducts and cyclobutane pyrimidine dimers. Effective repair of such lesions by the nucleotide excision repair (NER) pathway is required to prevent DNA mutations and chromosome aberrations. Poly(ADP-ribose) polymerase-1 (PARP-1) is a zinc finger protein with well documented involvement in base excision repair. PARP-1 is activated in response to DNA damage and catalyzes the formation of poly(ADP-ribose) subunits that assist in the assembly of DNA repair proteins at sites of damage. In this study, we present evidence for PARP-1 contributions to NER, extending the knowledge of PARP-1 function in DNA repair beyond the established role in base excision repair. Silencing the PARP-1 protein or inhibiting PARP activity leads to retention of UVR-induced photolesions. PARP activation following UVR exposure promotes association between PARP-1 and XPA, a central protein in NER. Administration of PARP inhibitors confirms that poly(ADP-ribose) facilitates PARP-1 association with XPA in whole cell extracts, in isolated chromatin complexes, and in vitro. Furthermore, inhibition of PARP activity decreases UVR-stimulated XPA chromatin association, illustrating that these relationships occur in a meaningful context for NER. These results provide a mechanistic link for PARP activity in the repair of UVR-induced photoproducts. PMID:23038248

Human OGG1 activity in nucleosomes is facilitated by transient unwrapping of DNA and is influenced by the local histone environment.

PubMed

Bilotti, Katharina; Kennedy, Erin E; Li, Chuxuan; Delaney, Sarah

2017-11-01

If unrepaired, damage to genomic DNA can cause mutations and/or be cytotoxic. Single base lesions are repaired via the base excision repair (BER) pathway. The first step in BER is the recognition and removal of the nucleobase lesion by a glycosylase enzyme. For example, human oxoguanine glycosylase 1 (hOGG1) is responsible for removal of the prototypic oxidatively damaged nucleobase, 8-oxo-7,8-dihydroguanine (8-oxoG). To date, most studies of glycosylases have used free duplex DNA substrates. However, cellular DNA is packaged as repeating nucleosome units, with 145 base pair segments of DNA wrapped around histone protein octamers. Previous studies revealed inhibition of hOGG1 at the nucleosome dyad axis and in the absence of chromatin remodelers. In this study, we reveal that even in the absence of chromatin remodelers or external cofactors, hOGG1 can initiate BER at positions off the dyad axis and that this activity is facilitated by spontaneous and transient unwrapping of DNA from the histones. Additionally, we find that solution accessibility as determined by hydroxyl radical footprinting is not fully predictive of glycosylase activity and that histone tails can suppress hOGG1 activity. We therefore suggest that local nuances in the nucleosome environment and histone-DNA interactions can impact glycosylase activity. Copyright © 2017 Elsevier B.V. All rights reserved.

Optimization, characterization, and efficacy evaluation of 2% chitosan scaffold for tissue engineering and wound healing

PubMed Central

Chhabra, Priyanka; Tyagi, Priyanka; Bhatnagar, Aseem; Mittal, Gaurav; Kumar, Amit

2016-01-01

Objective: To develop a chitosan-based scaffold and carry out a complete comprehensive study encompassing optimization of exact chitosan strength, product characterization, toxicity evaluation, in vitro validation in cell culture experiments, and finally in vivo efficacy in animal excision wound model. Materials and Methods: Developed chitosan scaffolds (CSs) were optimized for tissue engineering and wound healing efficacy by means of microstructure, toxicity, and biocompatibility evaluation. Results: Scanning electron microscope (SEM) studies revealed that porosity of CS decreased with increase in chitosan concentration. Chemical stability and integrity of scaffolds were confirmed by Fourier transform infrared studies. Highest swelling percentage (SP) of 500% was observed in 2%, while lowest (200%) was observed in 1% CS. Reabsorption and noncytotoxic property of optimized scaffold were established by enzymatic degradation and MTT assay. Enzymatic degradation suggested 20–45% of weight loss (WL) within 14 days of incubation. Cytotoxicity analysis showed that scaffolds were noncytotoxic against normal human dermal fibroblast human dermal fibroblast cell lines. Significant cellular adherence over the scaffold surface with normal cellular morphology was confirmed using SEM analysis. In vivo efficacy evaluation was carried out by means of reduction in wound size on Sprague-Dawley rats. Sprague-Dawley rats treated with optimized scaffold showed ~ 100% wound healing in comparison to ~80% healing in betadine-treated animals within 14 days. Histological examination depicted advance re-epithelization with better organization of collagen bundle in wound area treated with 2% CS in comparison to conventional treatment or no treatment. Conclusion: This study, thus, reveals that 2% CSs were found to have a great potential in wound healing. PMID:28216954

Communication: Site-selective bond excision of adenine upon electron transfer

NASA Astrophysics Data System (ADS)

Cunha, T.; Mendes, M.; Ferreira da Silva, F.; Eden, S.; García, G.; Limão-Vieira, P.

2018-01-01

This work demonstrates that selective excision of hydrogen atoms at a particular site of the DNA base adenine can be achieved in collisions with electronegative atoms by controlling the impact energy. The result is based on analysing the time-of-flight mass spectra yields of potassium collisions with a series of labeled adenine derivatives. The production of dehydrogenated parent anions is consistent with neutral H loss either from selective breaking of C-H or N-H bonds. These unprecedented results open up a new methodology in charge transfer collisions that can initiate selective reactivity as a key process in chemical reactions that are dominant in different areas of science and technology.

Experience of treatment of patients with granulomatous lobular mastitis

PubMed Central

Hur, Sung Mo; Cho, Dong Hui; Lee, Se Kyung; Choi, Min-Young; Bae, Soo Youn; Koo, Min Young; Kim, Sangmin; Choe, Jun-Ho; Kim, Jung-Han; Kim, Jee Soo; Nam, Seok-Jin; Yang, Jung-Hyun

2013-01-01

Purpose To present the author's experience with various treatment methods of granulomatous lobular mastitis (GLM) and to determine effective treatment methods of GLM. Methods Fifty patients who were diagnosed with GLM were classified into five groups based on the initial treatment methods they underwent, which included observation (n = 8), antibiotics (n = 3), steroid (n = 13), drainage (n = 14), and surgical excision (n = 12). The treatment processes in each group were examined and their clinical characteristics, treatment processes, and results were analyzed respectively. Results Success rates with each initial treatment were observation, 87.5%; antibiotics, 33.3%; steroids, 30.8%; drainage, 28.6%; and surgical excision, 91.7%. In most cases of observation, the lesions were small and the symptoms were mild. A total of 23 patients underwent surgical excision during treatment. Surgical excision showed particularly fast recovery, high success rate (90.3%) and low recurrence rate (8.7%). Conclusion The clinical course of GLM is complex and the outcome of each treatment type are variable. Surgery may play an important role when a lesion is determined to be mass-forming or appears localized as an abscess pocket during breast examination or imaging study. PMID:23833753

Psychrometric Field Measurement of Water Potential Changes following Leaf Excision.

PubMed

Savage, M J; Cass, A

1984-01-01

In situ measurement of sudden leaf water potential changes has not been performed under field conditions. A laboratory investigation involving the measurement of leaf water potential prior to and 2 to 200 minutes after excision of citrus leaves (Citrus jambhiri) showed good linear correlation (r = 0.99) between in situ leaf psychrometer and Scholander pressure chamber measurements. Following this, a field investigation was conducted which involved psychrometric measurement prior to petiole excision and 1 minute after excision. Simultaneous pressure chamber measurements were performed on neighboring leaves prior to the time of excision and then on the psychrometer leaf about 2 minutes after excision. These data indicate that within the first 2 minutes after excision, psychrometer and pressure chamber measurements were linearly correlated (r = 0.97). Under high evaporative demand conditions, the rate of water potential decrease was between 250 and 700 kilopascals in the first minute after excision. These results show that the thermocouple psychrometer can be used as a dynamic and nondestructive field technique for monitoring leaf water potential.

Psychrometric Field Measurement of Water Potential Changes following Leaf Excision 1

PubMed Central

Savage, Michael J.; Cass, Alfred

1984-01-01

In situ measurement of sudden leaf water potential changes has not been performed under field conditions. A laboratory investigation involving the measurement of leaf water potential prior to and 2 to 200 minutes after excision of citrus leaves (Citrus jambhiri) showed good linear correlation (r = 0.99) between in situ leaf psychrometer and Scholander pressure chamber measurements. Following this, a field investigation was conducted which involved psychrometric measurement prior to petiole excision and 1 minute after excision. Simultaneous pressure chamber measurements were performed on neighboring leaves prior to the time of excision and then on the psychrometer leaf about 2 minutes after excision. These data indicate that within the first 2 minutes after excision, psychrometer and pressure chamber measurements were linearly correlated (r = 0.97). Under high evaporative demand conditions, the rate of water potential decrease was between 250 and 700 kilopascals in the first minute after excision. These results show that the thermocouple psychrometer can be used as a dynamic and nondestructive field technique for monitoring leaf water potential. PMID:16663394

New insights about excisable pathogenicity islands in Salmonella and their contribution to virulence.

PubMed

Nieto, Pamela A; Pardo-Roa, Catalina; Salazar-Echegarai, Francisco J; Tobar, Hugo E; Coronado-Arrázola, Irenice; Riedel, Claudia A; Kalergis, Alexis M; Bueno, Susan M

2016-05-01

Pathogenicity islands (PAIs) are regions of the chromosome of pathogenic bacteria that harbor virulence genes, which were probably acquired by lateral gene transfer. Several PAIs can excise from the bacterial chromosome by site-specific recombination and in this review have been denominated "excisable PAIs". Here, the characteristic of some of the excisable PAIs from Salmonella enterica and the possible role and impact of the excision process on bacterial virulence is discussed. Understanding the role of PAI excision could provide important insights relative to the emergence, evolution and virulence of pathogenic enterobacteria. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Arthroscopic excision of ganglion cysts.

PubMed

Bontempo, Nicholas A; Weiss, Arnold-Peter C

2014-02-01

Arthroscopy is an advancing field in orthopedics, the applications of which have been expanding over time. Traditionally, excision of ganglion cysts has been done in an open fashion. However, more recently, studies show outcomes following arthroscopic excision to be as good as open excision. Cosmetically, the incisions are smaller and heal faster following arthroscopy. In addition, there is the suggested benefit that patients will regain function and return to work faster following arthroscopic excision. More prospective studies comparing open and arthroscopic excision of ganglion cysts need to be done in order to delineate if there is a true functional benefit. Copyright © 2014 Elsevier Inc. All rights reserved.

Staged margin-controlled excision (SMEX) for lentigo maligna melanoma in situ.

PubMed

Beveridge, Julie; Taher, Muba; Zhu, Jay; Mahmood, Muhammad N; Salopek, Thomas G

2018-06-24

No consensus exists regarding the best surgical strategy to achieve clear surgical margins while minimizing tissue excision when definitely excising lentigo maligna melanoma in situ (LM). The staged margin controlled excision (SMEX) technique is a modification of the spaghetti technique that allows surgeons to minimize margins and ensure complete excision of LM. Our objectives were twofold: a) to evaluate the effectiveness of SMEX for treatment of LM and b) detail the SMEX technique. A retrospective chart review of adult patients who underwent the SMEX technique for treatment of LM from 2011 to 2016 was conducted. Twenty-four patients were identified with predominantly facial lesions. The mean defect size was 12.1 cm 2 . A mean number of two SMEX procedures, with an average margin of 9 mm, were required to obtain complete excision of the LM. Using SMEX, we achieved 100% clearance of LM over a median follow up period of 18 months, with a range of 1-63 months. SMEX offers a reliable surgical excision method that ensures complete excision of LM in a cosmetically sensitive manner. The recurrence outcomes of SMEX are comparable, if not better, than those of alternative excision techniques in the literature. © 2018 Wiley Periodicals, Inc.

75 FR 9359 - Drawback of Internal Revenue Excise Tax

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-02

... Drawback of Internal Revenue Excise Tax AGENCY: Customs and Border Protection, Department of Homeland... substitution drawback claim for internal revenue excise tax paid on imported merchandise in situations where no excise tax was paid upon the substituted merchandise or where the substituted merchandise is the subject...

77 FR 43157 - Disregarded Entities and the Indoor Tanning Services Excise Tax; Correction

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-24

... Disregarded Entities and the Indoor Tanning Services Excise Tax; Correction AGENCY: Internal Revenue Service... disregarded entities (including qualified subchapter S subsidiaries) and the indoor tanning services excise... with respect to the indoor tanning services excise tax--(A) In general. Notwithstanding any other...

Who pays the most cigarette tax in Turkey.

PubMed

Önder, Zeynep; Yürekli, Ayda A

2016-01-01

Although higher taxation of tobacco products is considered the most cost-effective tobacco control policy, its negative impact on low-income groups is one of the arguments used against it. To investigate the impact of current excise taxes and the increases of excise taxes on tobacco and household expenditures by expenditure tertiles, and examine who pays excise taxes in general. Impacts of excise taxes on cigarettes are examined with a budgetary approach. We first estimate the price elasticity of cigarettes by expenditure tertiles using data from the 2003 Turkish Household Expenditure Survey, the most recent data set covering detailed tobacco product information relevant to our analysis. We then conduct a number of simulation analyses by increasing the excise taxes per pack of cigarettes and examine the impacts of these increases on household expenditures. Finally, as excise tax increases, we predict the total excise tax paid by households in different expenditure tertiles and compare the concentration curve of excise tax spending with the Lorenz curve showing the cumulative share of total household expenditures by expenditure tertiles. We estimate the progressivity coefficient that measures the area between the Lorenz and concentration curves. The low-income group is found to be the most sensitive to tax and price increases. It spends a relatively higher share of the household expenditure on cigarettes compared with higher income groups. However, the results suggest a different outcome as excise tax increases; the share of household expenditures spent on cigarettes declines for all household tertiles but a significant reduction occurs on the lowest expenditure tertile, suggesting that increases in excise taxes are progressive. Furthermore, the highest expenditure tertile pays the highest excise tax among expenditure tertiles, and their share in total excise revenue increases as the excise tax per pack of cigarettes increases. The poor smoking households benefit the most from increases in excise taxes; from a budgetary perspective, as they reduce their smoking consumption significantly, the share of their excise payment in total household expenditures declines. From a health perspective, they are likely to have more health benefits as their consumption reduces. Government revenues are also predicted to increase with increased excise taxes, and the government can allocate a part of these revenue increases on implementing and enforcing other tobacco control measures including cessation support and smoke-free environments. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Mobilization of the rectum: anatomic concepts and the bookshelf revisited.

PubMed

Chapuis, Pierre; Bokey, Les; Fahrer, Marius; Sinclair, Gael; Bogduk, Nikolai

2002-01-01

Sound surgical technique is based on accurate anatomic knowledge. In surgery for cancer, the anatomy of the perirectal fascia and the retrorectal plane is the basis for correct mobilization of the rectum to ensure clear surgical margins and to minimize the risk of local recurrence. This review of the literature on the perirectal fascia is based on a translation of the original description by Thoma Jonnesco and a later account by Wilhelm Waldeyer. The Jonnesco description, first published in 1896 in French, is compared with the German account of 1899. These were critically analyzed in the context of our own and other techniques of mobilizing the rectum. Mobilization of the rectum for cancer can be performed along anatomic planes with minimal blood loss, preservation of the pelvic autonomic nerves and a low prevalence of local recurrence. Different techniques including total mesorectal excision are based on the same anatomic principles, however, popular words have been used to replace accepted, established terminology. In particular, the description of total mesorectal excision has been confusing because of its emphasis on the words "total" and "mesorectum." The use of the word "mesorectum" anatomically is inaccurate and the implication that total excision of all the perirectal fat contained within the perirectal fascia "en bloc" in all patients with rectal cancer will minimize local recurrence remains contentious.

A fiber optic sensor for ophthalmic refractive diagnostics

NASA Technical Reports Server (NTRS)

Ansari, Rafat R.; Dhadwal, Harbans S.; Campbell, Melanie C. W.; Dellavecchia, Michael A.

1992-01-01

This paper demonstrates the application of a lensless fiber optic spectrometer (sensor) to study the onset of cataracts. This new miniaturized and rugged fiber optic probe is based upon dynamic light scattering (DLS) principles. It has no moving parts, no apertures, and requires no optical alignment. It is flexible and easy to use. Results are presented for cold-induced cataract in excised bovine eye lenses, and aging effects in excised human eye lenses. The device can be easily incorporated into a slit-lamp apparatus (ophthalmoscope) for complete eye diagnostics.

26 CFR 53.4955-1 - Tax on political expenditures.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 17 2010-04-01 2010-04-01 false Tax on political expenditures. 53.4955-1...) MISCELLANEOUS EXCISE TAXES (CONTINUED) FOUNDATION AND SIMILAR EXCISE TAXES Second Tier Excise Taxes § 53.4955-1 Tax on political expenditures. (a) Relationship between section 4955 excise taxes and substantive...

26 CFR 55.4982-1 - Imposition of excise tax on undistributed income of regulated investment companies.

Code of Federal Regulations, 2013 CFR

2013-04-01

... income of regulated investment companies. 55.4982-1 Section 55.4982-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) MISCELLANEOUS EXCISE TAXES (CONTINUED) EXCISE TAX ON REAL ESTATE INVESTMENT TRUSTS AND REGULATED INVESTMENT COMPANIES Excise Tax on Regulated Investment Companies...

26 CFR 55.4982-1 - Imposition of excise tax on undistributed income of regulated investment companies.

Code of Federal Regulations, 2010 CFR

2010-04-01

... income of regulated investment companies. 55.4982-1 Section 55.4982-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) MISCELLANEOUS EXCISE TAXES (CONTINUED) EXCISE TAX ON REAL ESTATE INVESTMENT TRUSTS AND REGULATED INVESTMENT COMPANIES Excise Tax on Regulated Investment Companies...

26 CFR 55.4982-1 - Imposition of excise tax on undistributed income of regulated investment companies.

Code of Federal Regulations, 2014 CFR

2014-04-01

... income of regulated investment companies. 55.4982-1 Section 55.4982-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) MISCELLANEOUS EXCISE TAXES (CONTINUED) EXCISE TAX ON REAL ESTATE INVESTMENT TRUSTS AND REGULATED INVESTMENT COMPANIES Excise Tax on Regulated Investment Companies...

26 CFR 55.4982-1 - Imposition of excise tax on undistributed income of regulated investment companies.

Code of Federal Regulations, 2011 CFR

2011-04-01

... income of regulated investment companies. 55.4982-1 Section 55.4982-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) MISCELLANEOUS EXCISE TAXES (CONTINUED) EXCISE TAX ON REAL ESTATE INVESTMENT TRUSTS AND REGULATED INVESTMENT COMPANIES Excise Tax on Regulated Investment Companies...

26 CFR 55.4982-1 - Imposition of excise tax on undistributed income of regulated investment companies.

Code of Federal Regulations, 2012 CFR

2012-04-01

... income of regulated investment companies. 55.4982-1 Section 55.4982-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) MISCELLANEOUS EXCISE TAXES (CONTINUED) EXCISE TAX ON REAL ESTATE INVESTMENT TRUSTS AND REGULATED INVESTMENT COMPANIES Excise Tax on Regulated Investment Companies...

77 FR 37838 - Disregarded Entities and the Indoor Tanning Services Excise Tax

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-25

... 1545-BK38 Disregarded Entities and the Indoor Tanning Services Excise Tax AGENCY: Internal Revenue... the indoor tanning services excise tax. These regulations affect disregarded entities responsible for collecting the indoor tanning services excise tax and owners of those disregarded entities. The text of the...

Hidden in Plain Sight: Subtle Effects of the 8-Oxoguanine Lesion on the Structure, Dynamics, and Thermodynamics of a 15-Base-Pair Oligodeoxynucleotide Duplex†

PubMed Central

Crenshaw, Charisse M.; Wade, Jacqueline E.; Arthanari, Haribabu; Frueh, Dominique; Lane, Benjamin F.; Núñez, Megan E.

2011-01-01

The base lesion 8-oxoguanine is formed readily by oxidation of DNA, potentially leading to G→T transversion mutations. Despite the apparent similarity of 8-oxoguanine-cytosine base pairs to normal guanine-cytosine base pairs, cellular base excision repair systems effectively recognize the lesion base. Here we apply several techniques to examine a single 8-oxoguanine lesion at the center of a nonpalindromic 15-mer duplex oligonucleotide in an effort to determine what, if anything, distinguishes an 8-oxoguanine-cytosine base pair from a normal base pair. The lesion duplex is globally almost indistinguishable from the unmodified parent duplex using CD spectroscopy and UV melting thermodynamics. The DNA mismatch-detecting photocleavage agent Rh(bpy)2chrysi3+ cleaves only weakly and nonspecifically, revealing that the 8oxoG-C pair is locally stable at the level of the individual base pairs. NMR spectra are also consistent with a well-conserved B-form duplex structure. In the 2D NOESY spectra, base-sugar and imino-imino crosspeaks are strikingly similar between parent and lesion duplexes. Changes in chemical shift due to the 8oxoG lesion are localized to its complementary cytosine and to the 2–3 base pairs immediately flanking the lesion on the lesion strand. Residues further removed from the lesion are shown to be unperturbed by its presence. Notably, imino exchange experiments indicate that the 8-oxoguanine-cytosine pair is strong and stable, with an apparent equilibrium constant for opening equal to that of other internal guanine-cytosine base pairs, on the order of 10−6. This collection of experiments shows that the 8-oxoguanine-cytosine base pair is incredibly stable and similar to the native pair. PMID:21902242

Techniques for Large-Scale Bacterial Genome Manipulation and Characterization of the Mutants with Respect to In Silico Metabolic Reconstructions.

PubMed

diCenzo, George C; Finan, Turlough M

2018-01-01

The rate at which all genes within a bacterial genome can be identified far exceeds the ability to characterize these genes. To assist in associating genes with cellular functions, a large-scale bacterial genome deletion approach can be employed to rapidly screen tens to thousands of genes for desired phenotypes. Here, we provide a detailed protocol for the generation of deletions of large segments of bacterial genomes that relies on the activity of a site-specific recombinase. In this procedure, two recombinase recognition target sequences are introduced into known positions of a bacterial genome through single cross-over plasmid integration. Subsequent expression of the site-specific recombinase mediates recombination between the two target sequences, resulting in the excision of the intervening region and its loss from the genome. We further illustrate how this deletion system can be readily adapted to function as a large-scale in vivo cloning procedure, in which the region excised from the genome is captured as a replicative plasmid. We next provide a procedure for the metabolic analysis of bacterial large-scale genome deletion mutants using the Biolog Phenotype MicroArray™ system. Finally, a pipeline is described, and a sample Matlab script is provided, for the integration of the obtained data with a draft metabolic reconstruction for the refinement of the reactions and gene-protein-reaction relationships in a metabolic reconstruction.

Synergistic antitumor cytotoxic actions of ascorbate and menadione on human prostate (DU145) cancer cells in vitro: nucleus and other injuries preceding cell death by autoschizis.

PubMed

Gilloteaux, Jacques; Jamison, James M; Neal, Deborah; Summers, Jack L

2014-04-01

Scanning (SEM) and transmission electron microscopy (TEM) were used to characterize the cytotoxic effects of ascorbate (VC), menadione (VK3), or a VC:VK3 combination on a human prostate carcinoma cell line (DU145) following a 1-h vitamin treatment and a subsequent 24-h incubation in culture medium. Cell alterations examined by light and electron microscopy were treatment-dependent with VC + VK3 >VK3 > VC > Sham. Oxidative stress-induced damage was found in most organelles. This report describes injuries in the tumor cell nucleus (chromatin and nucleolus), mitochondria, endomembranes, lysosomal bodies (autophagocytoses) and inclusions. Morphologic alterations suggest that cytoskeleton damage is likely responsible for the superficial cytoplasmic changes, including major changes in cell shape and size and the self-excising phenomena. Unlike apoptotic bodies, the excised pieces contain ribonucleoproteins, but not organelles. These deleterious events cause a progressive, significant reduction in the tumor cell size. During nuclear alterations, the nuclei maintain their envelope during chromatolysis and karyolysis until cell death, while nucleoli undergo a characteristic segregation of their components. In addition, changes in fat and glycogen storage are consistent the cytotoxic and metabolic alterations caused by the respective treatments. All cellular ultrastructural changes are consistent with cell death by autoschizis and not apoptosis or other kinds of cell death.

Mobile phone specific electromagnetic fields induce transient DNA damage and nucleotide excision repair in serum-deprived human glioblastoma cells.

PubMed

Al-Serori, Halh; Ferk, Franziska; Kundi, Michael; Bileck, Andrea; Gerner, Christopher; Mišík, Miroslav; Nersesyan, Armen; Waldherr, Monika; Murbach, Manuel; Lah, Tamara T; Herold-Mende, Christel; Collins, Andrew R; Knasmüller, Siegfried

2018-01-01

Some epidemiological studies indicate that the use of mobile phones causes cancer in humans (in particular glioblastomas). It is known that DNA damage plays a key role in malignant transformation; therefore, we investigated the impact of the UMTS signal which is widely used in mobile telecommunications, on DNA stability in ten different human cell lines (six brain derived cell lines, lymphocytes, fibroblasts, liver and buccal tissue derived cells) under conditions relevant for users (SAR 0.25 to 1.00 W/kg). We found no evidence for induction of damage in single cell gel electrophoresis assays when the cells were cultivated with serum. However, clear positive effects were seen in a p53 proficient glioblastoma line (U87) when the cells were grown under serum free conditions, while no effects were found in p53 deficient glioblastoma cells (U251). Further experiments showed that the damage disappears rapidly in U87 and that exposure induced nucleotide excision repair (NER) and does not cause double strand breaks (DSBs). The observation of NER induction is supported by results of a proteome analysis indicating that several proteins involved in NER are up-regulated after exposure to UMTS; additionally, we found limited evidence for the activation of the γ-interferon pathway. The present findings show that the signal causes transient genetic instability in glioma derived cells and activates cellular defense systems.

Oxidatively-induced DNA damage and base excision repair in euthymic patients with bipolar disorder.

PubMed

Ceylan, Deniz; Tuna, Gamze; Kirkali, Güldal; Tunca, Zeliha; Can, Güneş; Arat, Hidayet Ece; Kant, Melis; Dizdaroglu, Miral; Özerdem, Ayşegül

2018-05-01

Oxidatively-induced DNA damage has previously been associated with bipolar disorder. More recently, impairments in DNA repair mechanisms have also been reported. We aimed to investigate oxidatively-induced DNA lesions and expression of DNA glycosylases involved in base excision repair in euthymic patients with bipolar disorder compared to healthy individuals. DNA base lesions including both base and nucleoside modifications were measured using gas chromatography-tandem mass spectrometry and liquid chromatography-tandem mass spectrometry with isotope-dilution in DNA samples isolated from leukocytes of euthymic patients with bipolar disorder (n = 32) and healthy individuals (n = 51). The expression of DNA repair enzymes OGG1 and NEIL1 were measured using quantitative real-time polymerase chain reaction. The levels of malondialdehyde were measured using high performance liquid chromatography. Seven DNA base lesions in DNA of leukocytes of patients and healthy individuals were identified and quantified. Three of them had significantly elevated levels in bipolar patients when compared to healthy individuals. No elevation of lipid peroxidation marker malondialdehyde was observed. The level of OGG1 expression was significantly reduced in bipolar patients compared to healthy individuals, whereas the two groups exhibited similar levels of NEIL1 expression. Our results suggest that oxidatively-induced DNA damage occurs and base excision repair capacity may be decreased in bipolar patients when compared to healthy individuals. Measurement of oxidatively-induced DNA base lesions and the expression of DNA repair enzymes may be of great importance for large scale basic research and clinical studies of bipolar disorder. Copyright © 2018 Elsevier B.V. All rights reserved.

Resolution of vitiligo following excision of halo congenital melanocytic nevus: a rare case report.

PubMed

Wang, Kai; Wang, Zhi; Huang, Weiqing

2016-05-01

Halo congenital melanocytic nevus (CMN) associated with vitiligo is rare, especially with regard to CMN excision. Only two reports of excision of halo CMN following repigmentation of vitiligo are found in the literature. We present a case of a girl with halo CMN and periorbital vitiligo. The halo CMN was excised and followed by spontaneous improvement of vitiligo. The result suggests excision of the inciting lesion may be a promising way to control vitiligo. © 2015 Wiley Periodicals, Inc.

State-Specific Liquor Excise Taxes and Retail Prices in Eight U.S. States, 2012

PubMed Central

Siegel, Michael; Grundman, Jody; DeJong, William; Naimi, Timothy S.; King, Charles; Albers, Alison B.; Williams, Rebecca S.; Jernigan, David H.

2013-01-01

We investigated the relationship between state excise taxes and liquor prices in eight states, using 2012 data for 45 brands. We made 6,042 price observations among 177 liquor stores with online prices. Using a hierarchical model, we examined the relationship between excise taxes and product prices. State excise taxes were significantly related to liquor prices, with an estimated pass-through rate of 0.93. The proportion of price accounted for by excise taxes averaged 7.0%. We find that excise taxes do increase the price of alcohol, but states are not taking advantage of this opportunity to reduce alcohol-related morbidity and mortality. PMID:24159914

State-specific liquor excise taxes and retail prices in 8 US states, 2012.

PubMed

Siegel, Michael; Grundman, Jody; DeJong, William; Naimi, Timothy S; King, Charles; Albers, Alison B; Williams, Rebecca S; Jernigan, David H

2013-01-01

The authors investigated the relationship between state excise taxes and liquor prices in 8 states, using 2012 data for 45 brands. The authors made 6042 price observations among 177 liquor stores with online prices. Using a hierarchical model, the authors examined the relationship between excise taxes and product prices. State excise taxes were significantly related to liquor prices, with an estimated pass-through rate of 0.93. The proportion of price accounted for by excise taxes averaged 7.0%. The authors find that excise taxes do increase the price of alcohol, but states are not taking advantage of this opportunity to reduce alcohol-related morbidity and mortality.

26 CFR 53.4958-1 - Taxes on excess benefit transactions.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 17 2010-04-01 2010-04-01 false Taxes on excess benefit transactions. 53.4958-1...) MISCELLANEOUS EXCISE TAXES (CONTINUED) FOUNDATION AND SIMILAR EXCISE TAXES Second Tier Excise Taxes § 53.4958-1 Taxes on excess benefit transactions. (a) In general. Section 4958 imposes excise taxes on each excess...

76 FR 52862 - Time for Payment of Certain Excise Taxes, and Quarterly Excise Tax Payments for Small Alcohol...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-24

... 40 Cigars and cigarettes, Claims, Electronic fund transfers, Excise taxes, Labeling, Packaging and... that are not required to pay taxes through electronic funds transfer (EFT), this first payment period..., Electronic funds transfers, Excise taxes, Exports, Food additives, Fruit juices, Labeling, Liquors, Packaging...

Dysplastic nevi with severe atypia: Long-term outcomes in patients with and without re-excision.

PubMed

Engeln, Kathleen; Peters, Kaitlin; Ho, Jonhan; Jedrych, Jaroslaw; Winger, Daniel; Ferris, Laura Korb; Patton, Timothy

2017-02-01

Dysplastic nevi with severe atypia (severely dysplastic nevi [SDN]) are frequently re-excised because of the concern that these lesions may in fact represent early melanoma. Data on long-term follow-up of these patients are limited. We sought to determine the rate of subsequent melanoma development in patients with SDN who underwent re-excision versus those who did not and to determine factors associated with decision to re-excise. A retrospective single institutional study was conducted with 451 adult patients (mean age 41.3 years) with SDN biopsied between November 1994 and November 2004, with clinical follow-up of at least 5 years. In 451 patients with SDN, re-excision was performed on 36.6%. Two melanomas were diagnosed in the re-excision specimens. Subsequent metastatic melanoma developed in 7 patients, all of whom had a history of melanoma. Margin comments influenced decision to re-excise. This was a retrospective study at a single institution. Re-excision of all SDN may not be necessary. Copyright © 2016 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

Pleomorphic Adenoma of Base of Tongue: Is Midline Mandibulotomy Necessary for Approaching Benign Base Tongue Lesions?

PubMed Central

Bansal, Sandeep; Kalsotra, Gopika; Mohammed, Abdul Wadood; Bahl, Amanjit; Gupta, Ashok K.

2012-01-01

Objective. To report a rare presentation of pleomorphic adenoma, at base tongue, excised surgically by a transoral midline glossotomy technique without mandibulotomy. Case Report. Pleomorphic adenoma is a benign tumor of the salivary gland found rarely in the base of tongue. Surgery is the definitive treatment for this tumor, and different approaches have been mentioned in the literature. In our case we surgically excised the tumor by a transoral midline glossotomy technique without mandibulotomy where we combined the cosmetic advantage of transoral technique and the exposure advantage of a glossotomy technique. Discussion. We discuss the different approaches to oropharynx, their advantages and disadvantages. Primary transoral approach provides better cosmesis but less exposure whereas median labiomandibuloglossotomy approach provides more exposure but is cosmetically unacceptable. Conclusion. A transoral midline glossotomy approach without mandibulotomy provides wide exposure with acceptable cosmesis. PMID:22953125

Recent Advances in the Structural Mechanisms of DNA Glycosylases

PubMed Central

Brooks, Sonja C.; Adhikary, Suraj; Rubinson, Emily H.; Eichman, Brandt F.

2012-01-01

DNA glycosylases safeguard the genome by locating and excising a diverse array of aberrant nucleobases created from oxidation, alkylation, and deamination of DNA. Since the discovery 28 years ago that these enzymes employ a base flipping mechanism to trap their substrates, six different protein architectures have been identified to perform the same basic task. Work over the past several years has unraveled details for how the various DNA glycosylases survey DNA, detect damage within the duplex, select for the correct modification, and catalyze base excision. Here, we provide a broad overview of these latest advances in glycosylase mechanisms gleaned from structural enzymology, highlighting features common to all glycosylases as well as key differences that define their particular substrate specificities. PMID:23076011

Reflective type objective based spectral-domain phase-sensitive optical coherence tomography for high-sensitive structural and functional imaging of cochlear microstructures through intact bone of an excised guinea pig cochlea

NASA Astrophysics Data System (ADS)

Subhash, Hrebesh M.; Wang, Ruikang K.; Chen, Fangyi; Nuttall, Alfred L.

2013-03-01

Most of the optical coherence tomographic (OCT) systems for high resolution imaging of biological specimens are based on refractive type microscope objectives, which are optimized for specific wave length of the optical source. In this study, we present the feasibility of using commercially available reflective type objective for high sensitive and high resolution structural and functional imaging of cochlear microstructures of an excised guinea pig through intact temporal bone. Unlike conventional refractive type microscopic objective, reflective objective are free from chromatic aberrations due to their all-reflecting nature and can support a broadband of spectrum with very high light collection efficiency.

Genetic instability associated with loop or stem–loop structures within transcription units can be independent of nucleotide excision repair

PubMed Central

Burns, John A; Chowdhury, Moinuddin A; Cartularo, Laura; Berens, Christian; Scicchitano, David A

2018-01-01

Abstract Simple sequence repeats (SSRs) are found throughout the genome, and under some conditions can change in length over time. Germline and somatic expansions of trinucleotide repeats are associated with a series of severely disabling illnesses, including Huntington's disease. The underlying mechanisms that effect SSR expansions and contractions have been experimentally elusive, but models suggesting a role for DNA repair have been proposed, in particular the involvement of transcription-coupled nucleotide excision repair (TCNER) that removes transcription-blocking DNA damage from the transcribed strand of actively expressed genes. If the formation of secondary DNA structures that are associated with SSRs were to block RNA polymerase progression, TCNER could be activated, resulting in the removal of the aberrant structure and a concomitant change in the region's length. To test this, TCNER activity in primary human fibroblasts was assessed on defined DNA substrates containing extrahelical DNA loops that lack discernible internal base pairs or DNA stem–loops that contain base pairs within the stem. The results show that both structures impede transcription elongation, but there is no corresponding evidence that nucleotide excision repair (NER) or TCNER operates to remove them. PMID:29474673

Alkylpurine glycosylase D employs DNA sculpting as a strategy to extrude and excise damaged bases.

PubMed

Kossmann, Bradley; Ivanov, Ivaylo

2014-07-01

Alkylpurine glycosylase D (AlkD) exhibits a unique base excision strategy. Instead of interacting directly with the lesion, the enzyme engages the non-lesion DNA strand. AlkD induces flipping of the alkylated and opposing base accompanied by DNA stack compression. Since this strategy leaves the alkylated base solvent exposed, the means to achieve enzymatic cleavage had remained unclear. We determined a minimum energy path for flipping out a 3-methyl adenine by AlkD and computed a potential of mean force along this path to delineate the energetics of base extrusion. We show that AlkD acts as a scaffold to stabilize three distinct DNA conformations, including the final extruded state. These states are almost equivalent in free energy and separated by low barriers. Thus, AlkD acts by sculpting the global DNA conformation to achieve lesion expulsion from DNA. N-glycosidic bond scission is then facilitated by a backbone phosphate group proximal to the alkylated base.

Metrics of cellular and vascular infiltration of human acellular dermal matrix in ventral hernia repairs.

PubMed

Campbell, Kristin Turza; Burns, Nadja K; Ensor, Joe; Butler, Charles E

2012-04-01

Human acellular dermal matrix is used for ventral hernia repair, as it resists infection and remodels by means of surrounding tissue. However, the tissue source and impact of basement membrane on cell and vessel infiltration have not been determined. The authors hypothesized that musculofascia would be the primary tissue source of cells and vessels infiltrating into human acellular dermal matrix and that the basement membrane would inhibit infiltration. Fifty-six guinea pigs underwent inlay human acellular dermal matrix ventral hernia repair with the basement membrane oriented toward or away from the peritoneum. At postoperative weeks 1, 2, or 4, repair sites were completely excised. Histologic and immunohistochemical analyses were performed to quantify cell and vessel density within repair-site zones, including interface (lateral, beneath musculofascia) and center (beneath subcutaneous fat) zones. Cell and vessel quantities were compared as functions of zone, basement membrane orientation, and time. Cellular and vascular infiltration increased over time universally. The interface demonstrated greater mean cell density than the center (weeks 1 and 2, p = 0.01 and p < 0.0001, respectively). Cell density was greater with the basement membrane oriented toward the peritoneum at week 4 (p = 0.02). The interface zone had greater mean vessel density than the center zone at week 4 (p < 0.0001). Orienting the basement membrane toward the peritoneum increased vessel density at week 4 (p = 0.0004). Cellular and vascular infiltration into human acellular dermal matrix for ventral hernia repairs was greater from musculofascia than from subcutaneous fat, and the basement membrane inhibited cellular and vascular infiltration. Human acellular dermal matrix should be placed adjacent to the best vascularizing tissue to improve fibrovascular incorporation.

Histomorphometric analysis of collagen architecture of auricular keloids in an Asian population.

PubMed

Chong, Yosep; Park, Tae Hwan; Seo, Sang won; Chang, Choong Hyun

2015-03-01

Keloids are a pathologic condition of the reparative process, which present as excessive scar formation that involves various cells and cytokines. Many studies focusing on the histologic feature of keloids, however, have shown discordant results without consideration of architectural aspect of collagen structure. The purpose of this study was to demonstrate a schematic illustration of collagen architecture of keloids, specifically auricular keloids, and to analyze each part on the histomorphologic and morphometric basis. Thirty-nine surgically excised auricular keloids were retrieved from the file of Kangbuk Samsung Hospital. After exhaustive histomorphologic analysis, 3 distinctive structural parts, keloidal collagen, organizing collagen, and proliferating core collagen, were identified and mapped in every case. Cellularity of fibroblasts, blood vessel density, degree of inflammatory cell infiltration, and mast cells counts using Masson trichrome stain, Van Gieson stain, toluidine blue stain, and immunohistochemical stains for CD31 and smooth muscle actin were analyzed in each part of each case. Morphometric analysis on these parameters using ImageJ software was performed using 3 representative images of each part. Three parts were histomorphologically distinct by shape and array of collagen bundles, fibroblasts cellularity, blood vessel density, degree of inflammatory cells, and mast cell infiltration. Morphometric analysis revealed statistically significant difference between each part in fibroblasts cellularity, blood vessel density, degree of inflammatory cell infiltration, and mast cells count. All parameters were exceedingly high in whorling hypercellular fibrous nodules in proliferating core collagen showing simultaneous changes in other parts. Morphologically and morphometrically, 3 distinctive parts were identified in auricular keloids. Mast cell infiltrations, blood vessel density, and fibroblast cellularity are simultaneously increased or decreased according to these parts. Proliferating core collagen might serve as a proliferating center of keloids and might be a key portion for tumor growth and recurrence.

DNA repair pathways and mitochondrial DNA mutations in gastrointestinal carcinogenesis.

PubMed

Basso, Daniela; Navaglia, Filippo; Fogar, Paola; Zambon, Carlo-Federico; Greco, Eliana; Schiavon, Stefania; Fasolo, Michela; Stranges, Alessia; Falda, Alessandra; Padoan, Andrea; Fadi, Elisa; Pedrazzoli, Sergio; Plebani, Mario

2007-05-01

This work focuses on the main DNA repair pathways, highlighting their role in gastrointestinal carcinogenesis and the role of mitochondrial DNA (mtDNA), mutations being described in several tumor types, including those of the gastrointestinal tract. The mismatch repair (MMR) system is inherently altered in patients with hereditary non-polyposis colorectal cancer, and plays a role in carcinogenesis in a subset of sporadic colorectal, gastric and esophageal cancers. Alterations in homologous recombination (HR) and non-homologous end-joining (NHEJ) also contribute to the development of pancreatic cancer. Gene polymorphisms of some X-ray cross-complementing (XRCCs), cofactor proteins involved in the base excision repair pathway, have been investigated in relation to gastric, colorectal and pancreatic cancer. Yet only one polymorphism, XRCC1 Arg194Trp, appears to be involved in smoking-related cancers and in early onset pancreatic cancer. Although evidence in the literature indicates that mtDNA somatic mutations play a role in gastric and colorectal carcinogenesis, no sound conclusions have yet been drawn regarding this issue in pancreatic cancer, although an mtDNA variant at 16519 is believed to worsen the outcome of pancreatic cancer patients, possibly because it is involved in altering cellular metabolism.

Cell biological effects of hyperthermia alone or combined with radiation or drugs: a short introduction to newcomers in the field.

PubMed

Kampinga, Harm H

2006-05-01

Hyperthermia results in protein unfolding that, if not properly chaperoned by Heat Shock Proteins (HSP), can lead to irreversible and toxic protein aggregates. Elevating HSP prior to heating makes cells thermotolerant. Hyperthermia also can enhance the sensitivity of cells to radiation and drugs. This sensitization to drugs or radiation is not directly related to altered HSP expression. However, altering HSP expression before heat and radiation or drug treatment will affect the extent of thermal sensitization because the HSP will attenuate the heat-induced protein damage that is responsible for radiation- or drug-sensitization. For thermal radiosensitization, nuclear protein damage is considered to be responsible for hyperthermic effects on DNA repair, in particular base excision repair. Hyperthermic drug sensitization can be seen for a number of anti-cancer drugs, especially of alkylating agents. Synergy between heat and drugs may arise from multiple events such as heat damage to ABC transporters (drug accumulation), intra-cellular drug detoxification pathways and repair of drug-induced DNA adducts. This may be why cells with acquired drug resistance (often multi-factorial) can be made responsive to drugs again by combining the drug treatment with heat.

Maternal Geophagy of Calabash Chalk on Foetal Cerebral Cortex Histomorphology.

PubMed

Ekanem, Theresa Bassey; Ekong, Moses Bassey; Eluwa, Mokutima Amarachi; Igiri, Anozeng Oyono; Osim, Eme Efiom

2015-01-01

Calabash chalk, a kaolin-base substance is a common geophagic material mostly consumed by pregnant women. This study investigated its effect on the histomorphology of the foetal cerebral cortex. Twelve gestating Wistar rats were divided equally into groups 1 and 2. On pregnancy day seven (PD7), group 2 animals were administered 200 mg/kg body weight of calabash chalk suspension, while group 1 animals served as the control and received 1 ml of distilled water, by oral gavages and for 14 days (PD7-PD20). On PD21, the dams were sacrificed, and the foetuses removed, examined for gross malformations, weighed and culled to two foetuses per mother. Their whole brains were excised, weighed and preserved using 10% buffered formalin, and routinely processed by haematoxylin and eosin, and Luxol fast blue methods. The foetuses showed no morphological change, but their mean body weights was higher (p=0.0001). Histomorphological sections of the cerebral cortex showed hypertrophy and hyperplasia of cells in all the cortical layers, with less demonstrated Nissl and higher (p=0.001) cellular population compared with the control group. Calabash chalk cause body weight increase and histomorphological changes in the cerebral cortex of foetuses.

Replication-mediated disassociation of replication protein A–XPA complex upon DNA damage: implications for RPA handing off

PubMed Central

Jiang, Gaofeng; Zou, Yue; Wu, Xiaoming

2013-01-01

RPA (replication protein A), the eukaryotic ssDNA (single-stranded DNA)-binding protein, participates in most cellular processes in response to genotoxic insults, such as NER (nucleotide excision repair), DNA, DSB (double-strand break) repair and activation of cell cycle checkpoint signalling. RPA interacts with XPA (xeroderma pigmentosum A) and functions in early stage of NER. We have shown that in cells the RPA–XPA complex disassociated upon exposure of cells to high dose of UV irradiation. The dissociation required replication stress and was partially attributed to tRPA hyperphosphorylation. Treatment of cells with CPT (camptothecin) and HU (hydroxyurea), which cause DSB DNA damage and replication fork collapse respectively and also leads to the disruption of RPA–XPA complex. Purified RPA and XPA were unable to form complex in vitro in the presence of ssDNA. We propose that the competition-based RPA switch among different DNA metabolic pathways regulates the dissociation of RPA with XPA in cells after DNA damage. The biological significances of RPA–XPA complex disruption in relation with checkpoint activation, DSB repair and RPA hyperphosphorylation are discussed. PMID:22578086

Contribution of indirect effects to clustered damage in DNA irradiated with protons.

PubMed

Pachnerová Brabcová, K; Štěpán, V; Karamitros, M; Karabín, M; Dostálek, P; Incerti, S; Davídková, M; Sihver, L

2015-09-01

Protons are the dominant particles both in galactic cosmic rays and in solar particle events and, furthermore, proton irradiation becomes increasingly used in tumour treatment. It is believed that complex DNA damage is the determining factor for the consequent cellular response to radiation. DNA plasmid pBR322 was irradiated at U120-M cyclotron with 30 MeV protons and treated with two Escherichia coli base excision repair enzymes. The yields of SSBs and DSBs were analysed using agarose gel electrophoresis. DNA has been irradiated in the presence of hydroxyl radical scavenger (coumarin-3-carboxylic acid) in order to distinguish between direct and indirect damage of the biological target. Pure scavenger solution was used as a probe for measurement of induced OH· radical yields. Experimental OH· radical yield kinetics was compared with predictions computed by two theoretical models-RADAMOL and Geant4-DNA. Both approaches use Geant4-DNA for description of physical stages of radiation action, and then each of them applies a distinct model for description of the pre-chemical and chemical stage. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Metastatic malignant blue nevus: a case report.

PubMed

Ozgür, F; Akyürek, M; Kayikçioğlu, A; Barişta, I; Gököz, A

1997-10-01

This report presents a 63-year-old Caucasian woman with a malignant blue nevus, which is an extremely rare form of melanoma originating from or associated with a preexisting blue nevus. The background blue nevus on the left upper arm, which had been present for 5 to 6 years, increased in size and darkened in color for 3 months prior to histological diagnosis of malignant blue nevus. Although the tumor looked much like a nodular melanoma clinically, the diagnosis of malignant blue nevus was established histologically. The patient had a poor outcome due to metastatic spread of the tumor to the visceral organs 1 year following the initial excision of the tumor. To distinguish this rare tumor from other melanocytic lesions, strict histological criteria are needed to make the diagnosis of malignant blue nevus. Differential diagnosis includes cellular blue nevus, atypical cellular blue nevus, primary malignant melanoma, and metastatic melanoma to the dermis. Malignant blue nevus is most commonly seen on the scalp. The tumor has an aggressive behavior and metastasizes in the majority of patients. This paper describes the second reported case of malignant blue nevus involving the upper arm. Clinical and histological features of this uncommon tumor are presented, along with a review of the literature.

Combined loss of three DNA damage response pathways renders C. elegans intolerant to light.

PubMed

van Bostelen, Ivo; Tijsterman, Marcel

2017-06-01

Infliction of DNA damage initiates a complex cellular reaction - the DNA damage response - that involves both signaling and DNA repair networks with many redundancies and parallel pathways. Here, we reveal the three strategies that the simple multicellular eukaryote, C. elegans, uses to deal with DNA damage induced by light. Separately inactivating repair or replicative bypass of photo-lesions results in cellular hypersensitivity towards UV-light, but impeding repair of replication associated DNA breaks does not. Yet, we observe an unprecedented synergistic relationship when these pathways are inactivated in combination. C. elegans mutants that lack nucleotide excision repair (NER), translesion synthesis (TLS) and alternative end joining (altEJ) grow undisturbed in the dark, but become sterile when grown in light. Even exposure to very low levels of normal daylight impedes animal growth. We show that NER and TLS operate to suppress the formation of lethal DNA breaks that require polymerase theta-mediated end joining (TMEJ) for their repair. Our data testifies to the enormous genotoxicity of light and to the demand of multiple layers of protection against an environmental threat that is so common. Copyright © 2017 Elsevier B.V. All rights reserved.

The gingival Stillman's clefts: histopathology and cellular characteristics.

PubMed

Cassini, Maria Antonietta; Cerroni, Loredana; Ferlosio, Amedeo; Orlandi, Augusto; Pilloni, Andrea

2015-01-01

Stillman's cleft is a mucogingival triangular-shaped defect on the buccal surface of a root with unknown etiology and pathogenesis. The aim of this study is to examine the Stillman's cleft obtained from excision during root coverage surgical procedures at an histopathological level. Harvesting of cleft was obtained from two periodontally healthy patients with a scalpel and a bevel incision and then placed in a test tube with buffered solution to be processed for light microscopy. Microscopic analysis has shown that Stillman's cleft presented a lichenoid hand-like inflammatory infiltration, while in the periodontal patient an inflammatory fibrous hyperplasia was identified. Stillman's cleft remains to be investigated as for the possible causes of such lesion of the gingival margin, although an inflammatory response seems to be evident and active from a strictly histopathological standpoint.

Columnar cell lesions on breast needle biopsies: is surgical excision necessary? A systematic review.

PubMed

Verschuur-Maes, Anoek H J; van Deurzen, Carolien H M; Monninkhof, Evelyn M; van Diest, Paul J

2012-02-01

This systematic review was conducted to provide treatment recommendations for patients with a diagnosis of columnar cell lesions (CCLs) in a breast core needle biopsy (CNB). CCLs are putative breast cancer precursors and are often associated with (in situ) carcinoma in excision specimens. Although several studies reported on the progression risk and underestimation rate of a CNB diagnosis of CCL, there is no consensus regarding optimal clinical management in this context. We searched MEDLINE, Embase, and Cochrane databases from 1990 to October 2010 for studies on patients with a CNB diagnosis of CCL without atypia, CCL with atypia and atypical ductal hyperplasia associated with CCL followed by surgical excision or clinical follow up. Of 1759 selected articles, 24 were included in this review. The pooled underestimation risks for (in situ) carcinoma were as follow: CCL without atypia 1.5% (95% confidence interval [CI] 0.6%-4%), CCL with atypia 9% (95% CI: 5%-14%), and atypical ductal hyperplasia associated with CCL 20% (95% CI: 13%-28%), based on the whole groups of patients with a CNB. Studies including CCLs with long-term clinical follow-up showed a trend toward a limited elevated breast cancer risk. On the basis of the (in situ) carcinoma underestimation rates of patients with a CNB diagnosis of CCL with atypia and atypical ductal hyperplasia associated with CCL, surgical excision should be considered. For CCL without atypia, more studies with a long-term follow-up are required, but so far, surgical excision biopsy does not seem to be necessary.

Disparities in cigarette tax exposure by race, ethnicity, poverty status and sexual orientation, 2006-2014, USA.

PubMed

Golden, Shelley D; Kong, Amanda Y; Lee, Joseph G L; Ribisl, Kurt M

2018-03-01

Cigarette excise taxes are an effective tobacco control strategy but they vary geographically due to differences in state and local taxation. There are also pronounced sociodemographic differences in community composition, suggesting that different population groups might face vastly different cigarette excise tax rates. In this study, we examine how cigarette excise tax rates differ for population groups defined by race, ethnicity, poverty status, and sexual orientation, and how these differences have evolved over time. We constructed annual cigarette tax rates in 109 mutually exclusive jurisdictions within the United States (U.S.) between 2006 and 2014. After merging with Census sociodemographic data, we calculated annual cigarette excise tax exposures for each population group as the average of each place-based tax, weighted by the proportion of the group living there. In 2014, the average U.S. resident was required to pay $2.68 in cigarette taxes, more than 60% of which was due to state and local taxation. On average, Asian/Native Hawaiian and Other Pacific Islander populations faced the highest average tax ($2.95), which was $0.44 more than American Indian populations. Local taxes disproportionately augmented state and federal taxes for non-White populations, same-sex couples, and people living in poverty. Geographic variation in cigarette excise taxes produces sociodemographic variation in cigarette tax exposure. Raising cigarette taxes specifically in those places where groups at risk for tobacco-related disease are more likely to live, or otherwise creating geographically uniform tax levels, could reduce important disparities in cigarette smoking. Copyright © 2017. Published by Elsevier Inc.

[Non-palpable breast cancer malignant on needle core biopsy and no malignancy in surgical excision: how to manage?].

PubMed

Cheurfa, N; Giard, S

2015-01-01

Despite the standard management of non-palpable breast cancer (needle core biopsy diagnostic, accurate preoperative localization), there are differences in some cases between the malignant histo-pathological finding in diagnostic biopsy results and negative histo-pathological finding after surgical excision. The aim of this study is to evaluate this incidence and classifying them under three category: failure of surgical excision after preoperative identification; removal of the tumor was already completed by percutaneous biopsy; percutaneous biopsy true false positive. We conducted a study based on prospective database, all patients included in this study had partial mastectomy for ductal carcinoma in-situ or invasive cancer which was diagnosed by needle core biopsy and normal/benign after surgery. Regarding the partial mastectomy, 1863 was performed in the last three years in our center. Thirty-seven patients (2%) correspond our study criteria. After discussion of cases in our multidisciplinary reunion, 6 patients (16%) were considered as failure of surgical excision, 26 patients (70%) as true removal of the whole lesion in the core, and 5 patients (13%) as true false-positive cores. This is the first study witch investigate all factors that influence the results of negative final histo-pathological finding of surgical excision of the tumor after malignant diagnostic needle core biopsy. This rare situation need a multidisciplinary meeting to analyse all the steps of management and to determine causes of those false results and try to find adequate management to solve this problem. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Wound healing activity of extracts derived from Shorea robusta resin.

PubMed

Yaseen Khan, Mohammad; Ali, Saleh Abbas; Pundarikakshudu, Kilambi

2016-01-01

Shorea robusta Gaertn.f. (Dipterocarpaceae) resin is used for treating infected wounds and burns by tribals in India. The objective of this study was to investigate wound-healing activity of S. robusta resin extracts and essential oil in rats. Methanol extract (SRME), petroleum ether, benzene insoluble fraction of methanol extract (SRPEBIME), and essential oil (SREO) of S. robusta resin were incorporated in soft yellow paraffin (10% w/w) and applied once daily on incision and excision wounds of Wistar rats. Framycetin ointment (1.0% w/w) was applied to the standard group. Tensile strength (on the 10th day), wound contraction, and scar area (on the 14th day) were recorded. On the 15th day, granulation tissues of excision wounds were analyzed for total protein, hydroxyproline, and hexosamine contents and activities of lipid peroxidation and super oxide dismutase (SOD). Histopathology of the wounds was also studied. SRPEBIME and SREO healed incision and excision wounds faster than plain ointment base and framycetin. Tensile strength of SRPEBIME-treated incision wounds was 53% higher than that of control animals. In excision wounds, wound contraction and scar areas were found to be 99% and 7.7 mm(2) (SRPEBIME) and 71.7% and 21 mm(2) (control). Protein and hydroxyproline contents were higher in SRPEBIME (20.8 and 3.5% w/w) and SREO (17.4 and 2.8% w/w) groups as against 9.95 and 1.48% w/w in control groups. Histopathology revealed complete epithelization and new blood vessel formation in SRPEBIME groups. SRPEBIME and SREO have significant wound-healing activities on incision and excision wounds.

Xer1-Mediated Site-Specific DNA Inversions and Excisions in Mycoplasma agalactiae▿ ‡

PubMed Central

Czurda, Stefan; Jechlinger, Wolfgang; Rosengarten, Renate; Chopra-Dewasthaly, Rohini

2010-01-01

Surface antigen variation in Mycoplasma agalactiae, the etiologic agent of contagious agalactia in sheep and goats, is governed by site-specific recombination within the vpma multigene locus encoding the Vpma family of variable surface lipoproteins. This high-frequency Vpma phase switching was previously shown to be mediated by a Xer1 recombinase encoded adjacent to the vpma locus. In this study, it was demonstrated in Escherichia coli that the Xer1 recombinase is responsible for catalyzing vpma gene inversions between recombination sites (RS) located in the 5′-untranslated region (UTR) in all six vpma genes, causing cleavage and strand exchange within a 21-bp conserved region that serves as a recognition sequence. It was further shown that the outcome of the site-specific recombination event depends on the orientation of the two vpma RS, as direct or inverted repeats. While recombination between inverted vpma RS led to inversions, recombination between direct repeat vpma RS led to excisions. Using a newly developed excision assay based on the lacZ reporter system, we were able to successfully demonstrate under native conditions that such Xer1-mediated excisions can indeed also occur in the M. agalactiae type strain PG2, whereas they were not observed in the control xer1-disrupted VpmaY phase-locked mutant (PLMY), which lacks Xer1 recombinase. Unless there are specific regulatory mechanisms preventing such excisions, this might be the cost that the pathogen has to render at the population level for maintaining this high-frequency phase variation machinery. PMID:20562305

One-stop-shop with confocal microscopy imaging vs. standard care for surgical treatment of basal cell carcinoma: an open-label, noninferiority, randomized controlled multicentre trial.

PubMed

Kadouch, D J; Elshot, Y S; Zupan-Kajcovski, B; van Haersma de With, A S E; van der Wal, A C; Leeflang, M; Jóźwiak, K; Wolkerstorfer, A; Bekkenk, M W; Spuls, P I; de Rie, M A

2017-09-01

Routine punch biopsies are considered to be standard care for diagnosing and subtyping basal cell carcinoma (BCC) when clinically suspected. We assessed the efficacy of a one-stop-shop concept using in vivo reflectance confocal microscopy (RCM) imaging as a diagnostic tool vs. standard care for surgical treatment in patients with clinically suspected BCC. In this open-label, parallel-group, noninferiority, randomized controlled multicentre trial we enrolled patients with clinically suspected BCC at two tertiary referral centres in Amsterdam, the Netherlands. Patients were randomly assigned to the RCM one-stop-shop (diagnosing and subtyping using RCM followed by direct surgical excision) or standard care (planned excision based on the histological diagnosis and subtype of a punch biopsy). The primary outcome was the proportion of patients with tumour-free margins after surgical excision of BCC. Of the 95 patients included, 73 (77%) had a BCC histologically confirmed using a surgical excision specimen. All patients (40 of 40, 100%) in the one-stop-shop group had tumour-free margins. In the standard-care group tumour-free margins were found in all but two patients (31 of 33, 94%). The difference in the proportion of patients with tumour-free margins after BCC excision between the one-stop-shop group and the standard-care group was -0·06 (90% confidence interval -0·17-0·01), establishing noninferiority. The proposed new treatment strategy seems suitable in facilitating early diagnosis and direct treatment for patients with BCC, depending on factors such as availability of RCM, size and site of the lesion, patient preference and whether direct surgical excision is feasible. © 2017 The Authors. British Journal of Dermatology published by John Wiley & Sons Ltd on behalf of British Association of Dermatologists.

Removal of N-6-methyladenine by the nucleotide excision repair pathway triggers the repair of mismatches in yeast gap-repair intermediates.

PubMed

Guo, Xiaoge; Jinks-Robertson, Sue

2013-12-01

Gap-repair assays have been an important tool for studying the genetic control of homologous recombination in yeast. Sequence analysis of recombination products derived when a gapped plasmid is diverged relative to the chromosomal repair template additionally has been used to infer structures of strand-exchange intermediates. In the absence of the canonical mismatch repair pathway, mismatches present in these intermediates are expected to persist and segregate at the next round of DNA replication. In a mismatch repair defective (mlh1Δ) background, however, we have observed that recombination-generated mismatches are often corrected to generate gene conversion or restoration events. In the analyses reported here, the source of the aberrant mismatch removal during gap repair was examined. We find that most mismatch removal is linked to the methylation status of the plasmid used in the gap-repair assay. Whereas more than half of Dam-methylated plasmids had patches of gene conversion and/or restoration interspersed with unrepaired mismatches, mismatch removal was observed in less than 10% of products obtained when un-methylated plasmids were used in transformation experiments. The methylation-linked removal of mismatches in recombination intermediates was due specifically to the nucleotide excision repair pathway, with such mismatch removal being partially counteracted by glycosylases of the base excision repair pathway. These data demonstrate that nucleotide excision repair activity is not limited to bulky, helix-distorting DNA lesions, but also targets removal of very modest perturbations in DNA structure. In addition to its effects on mismatch removal, methylation reduced the overall gap-repair efficiency, but this reduction was not affected by the status of excision repair pathways. Finally, gel purification of DNA prior to transformation reduced gap-repair efficiency four-fold in a nucleotide excision repair-defective background, indicating that the collateral introduction of UV damage can potentially compromise genetic interpretations. Copyright © 2013 Elsevier B.V. All rights reserved.

Removal of N-6-methyladenine by the nucleotide excision repair pathway triggers the repair of mismatches in yeast gap-repair intermediates

PubMed Central

Guo, Xiaoge; Jinks-Robertson, Sue

2013-01-01

Gap-repair assays have been an important tool for studying the genetic control of homologous recombination in yeast. Sequence analysis of recombination products derived when a gapped plasmid is diverged relative to the chromosomal repair template additionally has been used to infer structures of strand-exchange intermediates. In the absence of the canonical mismatch repair pathway, mismatches present in these intermediates are expected to persist and segregate at the next round of DNA replication. In a mismatch repair defective (mlh1Δ) background, however, we have observed that recombination-generated mismatches are often corrected to generate gene conversion or restoration events. In the analyses reported here, the source of the aberrant mismatch removal during gap repair was examined. We find that most mismatch removal is linked to the methylation status of the plasmid used in the gap-repair assay. Whereas more than half of Dam-methylated plasmids had patches of gene conversion and/or restoration interspersed with unrepaired mismatches, mismatch removal was observed in less than 10% of products obtained when un-methylated plasmids were used in transformation experiments. The methylation-linked removal of mismatches in recombination intermediates was due specifically to the nucleotide excision repair pathway, with such mismatch removal being partially counteracted by glycosylases of the base excision repair pathway. These data demonstrate that nucleotide excision repair activity is not limited to bulky, helix-distorting DNA lesions, but also targets removal of very modest perturbations in DNA structure. In addition to its effects on mismatch removal, methylation reduced the overall gap-repair efficiency, but this reduction was not affected by the status of excision repair pathways. Finally, gel purification of DNA prior to transformation reduced gap-repair efficiency four-fold in a nucleotide excision repair-defective background, indicating that the cillateral introduction of UV damage can potentially compromise genetic interpretations. PMID:24120148

Public health: tobacco taxes and Internet sales--2005. End of Year Issue Brief.

PubMed

McKinley, Andrew

2005-12-31

Raising tobacco taxes is an action that resonates with lawmakers, public health and anti-tobacco advocates, and the majority of the electorate. The relatively broad base of support for increasing excise taxes and the potential for increased tax revenue mitigate the concerns over targeting tobacco-users--23 percent of the population--to pay for state programs and the unreliability of the tobacco tax as a permanent source of revenue. Tobacco excise taxes generated $10.2 billion, or about 1.5 percent of all states' revenue. Characterized as sin taxes or user fees and viewed as an effective method to deter price-sensitive adolescents from using tobacco, excise taxes on tobacco have increased in an unprecedented number of states since November 2001. Previously, no more than three states, on average, had increased cigarette taxes in a year. The legislative action is viewed as a politically safe and relatively easy way to raise taxes and increase revenue without incurring the wrath of anti-tax voters. During this period the increases in tobacco taxes ranged from a $0.12 per pack increase in Louisiana to a $0.75 increase in Massachusetts and Michigan. Nationwide the state tax rate per pack of cigarettes ranges from a low in South Carolina of $0.07 to $2.46 in Rhode Island. The mean tobacco excise tax for the nation is approximately $0.92. With an excise tax increase, states can channel needed funds to programs favored by voters in economically strapped times. Indeed, many of the 44 states that increased their tobacco tax announced that the revenue would permit the state to restore or at least reduce proposed cuts to Medicaid and other health programs. Excise taxes also place little administrative burden on states, since the wholesaler pays the tax directly to the state and the additional cost then is passed on to the consumer.

Posterior Endoscopic Excision of Os Trigonum in Professional National Ballet Dancers.

PubMed

Ballal, Moez S; Roche, Andy; Brodrick, Anna; Williams, R Lloyd; Calder, James D F

2016-01-01

Previous studies have compared the outcomes after open and endoscopic excision of an os trigonum in patients of mixed professions. No studies have compared the differences in outcomes between the 2 procedures in elite ballet dancers. From October 2005 to February 2010, 35 professional ballet dancers underwent excision of a symptomatic os trigonum of the ankle after a failed period of nonoperative treatment. Of the 35 patients, 13 (37.1%) underwent endoscopic excision and 22 (62.9%) open excision. We compared the outcomes, complications, and time to return to dancing. The open excision group experienced a significantly greater incidence of flexor hallucis longus tendon decompression compared with the endoscopic group. The endoscopic release group returned to full dance earlier at a mean of 9.8 (range 6.5 to 16.1) weeks and those undergoing open excision returned to full dance at a mean of 14.9 (range 9 to 20) weeks (p = .001). No major complications developed in either group, such as deep infection or nerve or vessel injury. We have concluded that both techniques are safe and effective in the treatment of symptomatic os trigonum in professional ballet dancers. Endoscopic excision of the os trigonum offers a more rapid return to full dance compared with open excision. Copyright © 2016 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

29 CFR 779.263 - Excise taxes not at the retail level.

Code of Federal Regulations, 2010 CFR

2010-07-01

... ACT AS APPLIED TO RETAILERS OF GOODS OR SERVICES Employment to Which the Act May Apply; Enterprise Coverage Excise Taxes § 779.263 Excise taxes not at the retail level. There are also a wide variety of... 29 Labor 3 2010-07-01 2010-07-01 false Excise taxes not at the retail level. 779.263 Section 779...

29 CFR 779.263 - Excise taxes not at the retail level.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 29 Labor 3 2013-07-01 2013-07-01 false Excise taxes not at the retail level. 779.263 Section 779... Coverage Excise Taxes § 779.263 Excise taxes not at the retail level. There are also a wide variety of taxes levied at the manufacturer's or distributor's level and not at the retail level. It should be...

29 CFR 779.263 - Excise taxes not at the retail level.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 29 Labor 3 2012-07-01 2012-07-01 false Excise taxes not at the retail level. 779.263 Section 779... Coverage Excise Taxes § 779.263 Excise taxes not at the retail level. There are also a wide variety of taxes levied at the manufacturer's or distributor's level and not at the retail level. It should be...

29 CFR 779.263 - Excise taxes not at the retail level.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 29 Labor 3 2011-07-01 2011-07-01 false Excise taxes not at the retail level. 779.263 Section 779... Coverage Excise Taxes § 779.263 Excise taxes not at the retail level. There are also a wide variety of taxes levied at the manufacturer's or distributor's level and not at the retail level. It should be...

29 CFR 779.263 - Excise taxes not at the retail level.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 29 Labor 3 2014-07-01 2014-07-01 false Excise taxes not at the retail level. 779.263 Section 779... Coverage Excise Taxes § 779.263 Excise taxes not at the retail level. There are also a wide variety of taxes levied at the manufacturer's or distributor's level and not at the retail level. It should be...

Otoplasty: the case for skin incision by higher volume operators.

PubMed

Arkoulis, Nikolaos; Reid, Jenny; Neill, Conor O '; Stewart, Kenneth J

2015-02-01

Prominent ear correction in the paediatric population is a common and popular procedure, with demonstrable benefit in alleviating psychological distress. Posterior cartilage-sparing techniques for otoplasty have been shown to be consistently safer and better than cartilage-scoring alternatives, however excision of the posterior auricular skin during otoplasty, although a common first step, has not been shown to have any benefits over skin incision alone. In this study, we examined the association between skin excision and recurrence of ear prominence, by examining the collective surgical outcomes of five plastic surgeons, performing 118 otoplasties at the Royal Hospital for Sick Children Edinburgh, between January 2011 and December 2013. Recurrence of prominence at the first follow-up appointment (mean follow-up 3.4 months) was 10.2%. Surgeons with low case volumes had significantly higher recurrence rates than high volume operators. There was no statistically significant association between skin excision and recurrence of prominence. We still favour posterior, cartilage-sparing otoplasties, but based on our findings we do not advocate any skin excision at any stage of the procedure. Surgeons should not include paediatric otoplasty in their portfolio unless they are undertaking significant number of cases each year. Copyright © 2014 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Intra-operative ultrasound-based augmented reality guidance for laparoscopic surgery.

PubMed

Singla, Rohit; Edgcumbe, Philip; Pratt, Philip; Nguan, Christopher; Rohling, Robert

2017-10-01

In laparoscopic surgery, the surgeon must operate with a limited field of view and reduced depth perception. This makes spatial understanding of critical structures difficult, such as an endophytic tumour in a partial nephrectomy. Such tumours yield a high complication rate of 47%, and excising them increases the risk of cutting into the kidney's collecting system. To overcome these challenges, an augmented reality guidance system is proposed. Using intra-operative ultrasound, a single navigation aid, and surgical instrument tracking, four augmentations of guidance information are provided during tumour excision. Qualitative and quantitative system benefits are measured in simulated robot-assisted partial nephrectomies. Robot-to-camera calibration achieved a total registration error of 1.0 ± 0.4 mm while the total system error is 2.5 ± 0.5 mm. The system significantly reduced healthy tissue excised from an average (±standard deviation) of 30.6 ± 5.5 to 17.5 ± 2.4 cm 3 ( p < 0.05) and reduced the depth from the tumor underside to cut from an average (±standard deviation) of 10.2 ± 4.1 to 3.3 ± 2.3 mm ( p < 0.05). Further evaluation is required in vivo, but the system has promising potential to reduce the amount of healthy parenchymal tissue excised.

Visualization of 3D elbow kinematics using reconstructed bony surfaces

NASA Astrophysics Data System (ADS)

Lalone, Emily A.; McDonald, Colin P.; Ferreira, Louis M.; Peters, Terry M.; King, Graham J. W.; Johnson, James A.

2010-02-01

An approach for direct visualization of continuous three-dimensional elbow kinematics using reconstructed surfaces has been developed. Simulation of valgus motion was achieved in five cadaveric specimens using an upper arm simulator. Direct visualization of the motion of the ulna and humerus at the ulnohumeral joint was obtained using a contact based registration technique. Employing fiducial markers, the rendered humerus and ulna were positioned according to the simulated motion. The specific aim of this study was to investigate the effect of radial head arthroplasty on restoring elbow joint stability after radial head excision. The position of the ulna and humerus was visualized for the intact elbow and following radial head excision and replacement. Visualization of the registered humerus/ulna indicated an increase in valgus angulation of the ulna with respect to the humerus after radial head excision. This increase in valgus angulation was restored to that of an elbow with a native radial head following radial head arthroplasty. These findings were consistent with previous studies investigating elbow joint stability following radial head excision and arthroplasty. The current technique was able to visualize a change in ulnar position in a single DoF. Using this approach, the coupled motion of ulna undergoing motion in all 6 degrees-of-freedom can also be visualized.

[Transfusional requirements for escharectomy in burned children].

PubMed

Julia, Analía R; Basílico, Hugo; Magaldi, Gustavo; Demirdjian, Graciela

2010-02-01

Early excision has considerably improved outcome in extensive burns, but massive resections usually mean copious bleeding that must be conveniently corrected. The purpose of this study was to measure blood component use during escharectomies in children. All pediatric patients with acute burns excised at the Burn Unit of the Hospital Garrahan during one year were included. Volume of blood component used during and immediately after surgery was analyzed and related to percent excised, time post-burn, and the coexistence of infection and autograft at the time of excision. Ninety-four surgeries in 51 children aged 0-14 years with total burned body surface areas of 5-80% who underwent resections of 3-70% were studied. Total blood use (intra + post-operatively) was 2.07 ml/kg/%excised for red blood cells (60% during surgery) and 0.7 ml/kg/% excised for plasma. Only 12% of patients required platelet transfusion. There was no significant requirement variation with the existence of infection, grafting or time post-burn. Approximately 2 ml/kg/% excised of red blood cells (2/3 for surgery) and 1 ml/kg/% excised of plasma are needed for escharectomies in children. The need for platelets must be judged considering the individual patient.

Dimer excision in Escherichia coli in the presence of caffeine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rothman, R.H.

1980-07-01

The observation that polA1 and recL152 mutations result in both slow pyrimidine dimer excision and large repair patch size leads to the hypothesis that patch size is directly related to the rate of excision. In this study caffeine, a known inhibitor of excision repair, was used to examine the extent of correlation between excision rate and patch size by measuring patch size in the presence of several concentrations of caffeine. Both the rate of excision and the resistance to ultraviolet radiation were reduced with increasing concentrations of caffeine after irradiation. Caffeine also inhibited the rate at which incisions were mademore » and prolonged the time required to rejoin the discontinuities. Patch size, however, was unaffected by caffeine treatment.« less

Aggressive fibromatosis (fibrosarcoma) of the facial nerve.

PubMed

Pulec, J L

1993-07-01

Aggressive fibromatosis of the facial nerve is a very rare tumor. Three cases have been previously reported. The tumor is locally recurrent and often has a fatal outcome. This report is of a ten-year-old boy whose tumor originally developed in the parotid area with subsequent spread to the base of the skull, the neck and the cerebellopontine angle. Treatment was by wide surgical excision, radiation therapy and chemotherapy. Despite treatment, the patient died. The clinical features of this case will be described. Only wide surgical excision early in the course of the disease may offer a chance for cure.

The human endonuclease III enzyme is a relevant target to potentiate cisplatin cytotoxicity in Y-box-binding protein-1 overexpressing tumor cells.

PubMed

Guay, David; Garand, Chantal; Reddy, Shanti; Schmutte, Chris; Lebel, Michel

2008-04-01

Y-box-binding protein-1 (YB-1) is a multifunctional protein involved in the regulation of transcription, translation, and mRNA splicing. In recent years, several laboratories have demonstrated that YB-1 is directly involved in the cellular response to genotoxic stress. Importantly, YB-1 is increased in tumor cell lines resistant to cisplatin, and the level of nuclear expression of YB-1 is predictive of drug resistance and patient outcome in breast tumors, ovarian cancers, and synovial sarcomas. YB-1 binds to several DNA repair enzymes in vitro including human endonuclease III (hNTH1). Human NTH1 is a bifunctional DNA glycosylase/apurinic/apyrimidinic lyase involved in base excision repair. In this study, we show that YB-1 binds specifically to the auto-inhibitory domain of hNTH1, providing a mechanism by which YB-1 stimulates hNTH1 activity. Indeed, YB-1 strongly stimulates in vitro the activity of hNTH1 toward DNA duplex probes containing oxidized bases, lesions prone to be present in cisplatin treated cells. We also observed an increase in YB-1/hNTH1 complex formation in the mammary adenocarcinoma MCF7 cell line treated with UV light and cisplatin. Such an increase was not observed with mitomycin C or the topoisomerase I inhibitor camptothecin. Accordingly, antisense RNAs against either YB-1 or hNTH1 increased cellular sensitivity to UV and cisplatin but not to mitomycin C. An antisense RNA against YB-1 increased camptothecin sensitivity. In contrast, an antisense against hNTH1 did not. Finally, siRNA against hNTH1 re-established cytotoxicity in otherwise cisplatin-resistant YB-1 overexpressing MCF7 cells. These data indicate that hNTH1 is a relevant target to potentiate cisplatin cytotoxicity in YB-1 overexpressing tumor cells.

The formation of catalytically competent enzyme-substrate complex is not a bottleneck in lesion excision by human alkyladenine DNA glycosylase.

PubMed

Kuznetsov, N A; Kiryutin, A S; Kuznetsova, A A; Panov, M S; Barsukova, M O; Yurkovskaya, A V; Fedorova, O S

2017-04-01

Human alkyladenine DNA glycosylase (AAG) protects DNA from alkylated and deaminated purine lesions. AAG flips out the damaged nucleotide from the double helix of DNA and catalyzes the hydrolysis of the N-glycosidic bond to release the damaged base. To understand better, how the step of nucleotide eversion influences the overall catalytic process, we performed a pre-steady-state kinetic analysis of AAG interaction with specific DNA-substrates, 13-base pair duplexes containing in the 7th position 1-N6-ethenoadenine (εA), hypoxanthine (Hx), and the stable product analogue tetrahydrofuran (F). The combination of the fluorescence of tryptophan, 2-aminopurine, and 1-N6-ethenoadenine was used to record conformational changes of the enzyme and DNA during the processes of DNA lesion recognition, damaged base eversion, excision of the N-glycosidic bond, and product release. The thermal stability of the duplexes characterized by the temperature of melting, T m , and the rates of spontaneous opening of individual nucleotide base pairs were determined by NMR spectroscopy. The data show that the relative thermal stability of duplexes containing a particular base pair in position 7, (T m (F/T) < T m (εA/T) < T m (Hx/T) < T m (A/T)) correlates with the rate of reversible spontaneous opening of the base pair. However, in contrast to that, the catalytic lesion excision rate is two orders of magnitude higher for Hx-containing substrates than for substrates containing εA, proving that catalytic activity is not correlated with the stability of the damaged base pair. Our study reveals that the formation of the catalytically competent enzyme-substrate complex is not the bottleneck controlling the catalytic activity of AAG.

Bisphenol A Promotes Cell Survival Following Oxidative DNA Damage in Mouse Fibroblasts

PubMed Central

Gassman, Natalie R.; Coskun, Erdem; Stefanick, Donna F.; Horton, Julie K.; Jaruga, Pawel; Dizdaroglu, Miral; Wilson, Samuel H.

2015-01-01

Bisphenol A (BPA) is a biologically active industrial chemical used in production of consumer products. BPA has become a target of intense public scrutiny following concerns about its association with human diseases such as obesity, diabetes, reproductive disorders, and cancer. Recent studies link BPA with the generation of reactive oxygen species, and base excision repair (BER) is responsible for removing oxidatively induced DNA lesions. Yet, the relationship between BPA and BER has yet to be examined. Further, the ubiquitous nature of BPA allows continuous exposure of the human genome concurrent with the normal endogenous and exogenous insults to the genome, and this co-exposure may impact the DNA damage response and repair. To determine the effect of BPA exposure on base excision repair of oxidatively induced DNA damage, cells compromised in double-strand break repair were treated with BPA alone or co-exposed with either potassium bromate (KBrO3) or laser irradiation as oxidative damaging agents. In experiments with KBrO3, co-treatment with BPA partially reversed the KBrO3-induced cytotoxicity observed in these cells, and this was coincident with an increase in guanine base lesions in genomic DNA. The improvement in cell survival and the increase in oxidatively induced DNA base lesions were reminiscent of previous results with alkyl adenine DNA glycosylase-deficient cells, suggesting that BPA may prevent initiation of repair of oxidized base lesions. With laser irradiation-induced DNA damage, treatment with BPA suppressed DNA repair as revealed by several indicators. These results are consistent with the hypothesis that BPA can induce a suppression of oxidized base lesion DNA repair by the base excision repair pathway. PMID:25693136

Single incision endoscopic surgery for gynaecomastia.

PubMed

Jarrar, G; Peel, A; Fahmy, R; Deol, H; Salih, V; Mostafa, A

2011-09-01

Surgical excision has been an effective treatment for gynaecomastia. Recently, there has been a shift from the open approach to minimally invasive techniques. In this report we describe our technique which includes endoscopic excision and/or liposuction of gynaecomastia via a single lateral chest wall incision. Between May 2007 and April 2010, a total of 12 gynaecomastia patients were treated with liposuction and/or endoscopic excision. Patients were divided into 3 groups: group I; liposuction only, group II; endoscopic excision plus liposuction and group III; endoscopic excision only. One 15 mm incision was made laterally at the anterior axillary line. A vacuum assisted liposuction removing the fatty tissue was performed. Then endoscopic excision of the remaining fibroglandular tissue was done under vision through the same incision. The parynchyma was then dissected into small pieces and pulled out. Group I had liposuction only (n = 4), group II had liposuction combined with endoscopic excision (n = 7) (58%) while group III had endoscopic excision only (n = 1). The mean operative time for liposuction and endoscopic excision was 58 min for each side. Mean hospital stay was 1.4 days. Postoperative complications included infection with abscess formation and one patient had seroma. Mean follow-up was 56 weeks. Eleven out of twelve patients (92%) were satisfied with their results. Long-term follow-up showed that results were stable over time, and no revisions were necessary. Endoscopic excision of gynaecomastia through a single lateral chest wall incision is a minimally invasive effective and safe technique for the management of gynaecomastia, with excellent aesthetic results and an acceptable complication rate. Copyright © 2011 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Estrogen Drives Cellular Transformation and Mutagenesis in Cells Expressing the Breast Cancer-Associated R438W DNA Polymerase Lambda Protein.

PubMed

Nemec, Antonia A; Bush, Korie B; Towle-Weicksel, Jamie B; Taylor, B Frazier; Schulz, Vincent; Weidhaas, Joanne B; Tuck, David P; Sweasy, Joann B

2016-11-01

Repair of DNA damage is critical for maintaining the genomic integrity of cells. DNA polymerase lambda (POLL/Pol λ) is suggested to function in base excision repair (BER) and nonhomologous end-joining (NHEJ), and is likely to play a role in damage tolerance at the replication fork. Here, using next-generation sequencing, it was discovered that the POLL rs3730477 single-nucleotide polymorphism (SNP) encoding R438W Pol λ was significantly enriched in the germlines of breast cancer patients. Expression of R438W Pol λ in human breast epithelial cells induces cellular transformation and chromosomal aberrations. The role of estrogen was assessed as it is commonly used in hormone replacement therapies and is a known breast cancer risk factor. Interestingly, the combination of estrogen treatment and the expression of the R438W Pol λ SNP drastically accelerated the rate of transformation. Estrogen exposure produces 8-oxoguanine lesions that persist in cells expressing R438W Pol λ compared with wild-type (WT) Pol λ-expressing cells. Unlike WT Pol λ, which performs error-free bypass of 8-oxoguanine lesions, expression of R438W Pol λ leads to an increase in mutagenesis and replicative stress in cells treated with estrogen. Together, these data suggest that individuals who carry the rs3730477 POLL germline variant have an increased risk of estrogen-associated breast cancer. The Pol λ R438W mutation can serve as a biomarker to predict cancer risk and implicates that treatment with estrogen in individuals with this mutation may further increase their risk of breast cancer. Mol Cancer Res; 14(11); 1068-77. ©2016 AACR. ©2016 American Association for Cancer Research.

The financial burden of reexcising incompletely excised soft tissue sarcomas: a cost analysis.

PubMed

Alamanda, Vignesh K; Delisca, Gadini O; Mathis, Shannon L; Archer, Kristin R; Ehrenfeld, Jesse M; Miller, Mark W; Homlar, Kelly C; Halpern, Jennifer L; Schwartz, Herbert S; Holt, Ginger E

2013-09-01

Although survival outcomes have been evaluated between those undergoing a planned primary excision and those undergoing a reexcision following an unplanned resection, the financial implications associated with a reexcision have yet to be elucidated. A query for financial data (professional, technical, indirect charges) for soft tissue sarcoma excisions from 2005 to 2008 was performed. A total of 304 patients (200 primary excisions and 104 reexcisions) were identified. Wilcoxon rank sum tests and χ2 or Fisher's exact tests were used to compare differences in demographics and tumor characteristics. Multivariable linear regression analyses were performed with bootstrapping techniques. The average professional charge for a primary excision was $9,694 and $12,896 for a reexcision (p<.001). After adjusting for tumor size, American Society of Anesthesiologists status, grade, and site, patients undergoing reexcision saw an increase of $3,699 in professional charges more than those with a primary excision (p<.001). Although every 1-cm increase in size of the tumor results in an increase of $148 for a primary excision (p=.006), size was not an independent factor in affecting reexcision charges. The grade of the tumor was positively associated with professional charges of both groups such that higher-grade tumors resulted in higher charges compared to lower-grade tumors (p<.05). Reexcision of an incompletely excised sarcoma results in significantly higher professional charges when compared to a single, planned complete excision. Additionally, when the cost of the primary unplanned surgery is considered, the financial burden nearly doubles.

Oxidized nucleotide insertion by pol β confounds ligation during base excision repair

PubMed Central

Çağlayan, Melike; Horton, Julie K.; Dai, Da-Peng; Stefanick, Donna F.; Wilson, Samuel H.

2017-01-01

Oxidative stress in cells can lead to accumulation of reactive oxygen species and oxidation of DNA precursors. Oxidized purine nucleotides can be inserted into DNA during replication and repair. The main pathway for correcting oxidized bases in DNA is base excision repair (BER), and in vertebrates DNA polymerase β (pol β) provides gap filling and tailoring functions. Here we report that the DNA ligation step of BER is compromised after pol β insertion of oxidized purine nucleotides into the BER intermediate in vitro. These results suggest the possibility that BER mediated toxic strand breaks are produced in cells under oxidative stress conditions. We observe enhanced cytotoxicity in oxidizing-agent treated pol β expressing mouse fibroblasts, suggesting formation of DNA strand breaks under these treatment conditions. Increased cytotoxicity following MTH1 knockout or treatment with MTH1 inhibitor suggests the oxidation of precursor nucleotides. PMID:28067232

Low-level laser irradiation alters mRNA expression from genes involved in DNA repair and genomic stabilization in myoblasts

NASA Astrophysics Data System (ADS)

Trajano, L. A. S. N.; Sergio, L. P. S.; Silva, C. L.; Carvalho, L.; Mencalha, A. L.; Stumbo, A. C.; Fonseca, A. S.

2016-07-01

Low-level lasers are used for the treatment of diseases in soft and bone tissues, but few data are available regarding their effects on genomic stability. In this study, we investigated mRNA expression from genes involved in DNA repair and genomic stabilization in myoblasts exposed to low-level infrared laser. C2C12 myoblast cultures in different fetal bovine serum concentrations were exposed to low-level infrared laser (10, 35 and 70 J cm-2), and collected for the evaluation of DNA repair gene expression. Laser exposure increased gene expression related to base excision repair (8-oxoguanine DNA glycosylase and apurinic/apyrimidinic endonuclease 1), nucleotide excision repair (excision repair cross-complementation group 1 and xeroderma pigmentosum C protein) and genomic stabilization (ATM serine/threonine kinase and tumor protein p53) in normal and low fetal bovine serum concentrations. Results suggest that genomic stability could be part of a biostimulation effect of low-level laser therapy in injured muscles.

Base excision repair in Archaea: back to the future in DNA repair.

PubMed

Grasso, Stefano; Tell, Gianluca

2014-09-01

Together with Bacteria and Eukarya, Archaea represents one of the three domain of life. In contrast with the morphological difference existing between Archaea and Eukarya, these two domains are closely related. Phylogenetic analyses confirm this evolutionary relationship showing that most of the proteins involved in DNA transcription and replication are highly conserved. On the contrary, information is scanty about DNA repair pathways and their mechanisms. In the present review the most important proteins involved in base excision repair, namely glycosylases, AP lyases, AP endonucleases, polymerases, sliding clamps, flap endonucleases, and ligases, will be discussed and compared with bacterial and eukaryotic ones. Finally, possible applications and future perspectives derived from studies on Archaea and their repair pathways, will be taken into account. Copyright © 2014 Elsevier B.V. All rights reserved.

Preoperative immunosuppressive therapy and surgery as a treatment for anal furunculosis.

PubMed

Klein, Arnaud; Deneuche, Aymeric; Fayolle, Pascal; Hidalgo, Antoine; Scotti, Stefano; Zylberstein, Luca; Desbois, Christophe; Tessier, Dominique; Moissonnier, Pierre; Viateau, Véronique

2006-12-01

To evaluate the efficacy of combining preoperative immunosuppressive therapy with surgical excision for treatment of anal furunculosis (AF) in dogs. Retrospective study. Dogs (n=25) with stages 1-4 AF. Preoperative immunosuppressive therapy was either cyclosporine A (CyA) alone or in combination with ketoconazole (Group 1; n=18), or azathioprine combined with prednisolone (Group 2; n=7). Surgical excision of residual draining tracts, cryptectomy, and anal sacculectomy were performed. Only dogs with postoperative clinical follow-up exceeding 9 months were retained for the study. Both immunosuppressive protocols were effective in reducing progression of AF. Subsequent draining tracts excision, cryptectomy, and anal sacculectomy were bilateral (12 dogs) or unilateral (13 dogs of which 4 had bilateral anal sacculectomy). Postoperative recovery was uneventful, except for 2 dogs that had wound breakdown. Recurrence was not observed in any of the dogs that had bilateral surgical excision and or in 9 dogs that had unilateral excision. Preoperative immunosuppressive therapy, combined with bilateral surgical resection of affected tissue consistently, resulted in resolution of AF. Four dogs that had recurrence had unilateral excision despite initial bilateral involvement, suggesting that all diseased tissue should be excised. These preliminary results suggest that immunosuppressive therapy before surgical excision for AF yields minimizes recurrence in dogs.

Infrequent transposition of Ac in lettuce, Lactuca sativa.

PubMed

Yang, C H; Ellis, J G; Michelmore, R W

1993-08-01

The maize transposable element Activator (Ac) is being used to develop a transposon mutagenesis system in lettuce, Lactuca sativa. Two constructs containing the complete Ac from the waxy-m7 locus of maize were introduced into lettuce and monitored for activity using Southern analysis and PCR amplification of the excision site. No transposition of Ac was detected in over 32 transgenic R1 plants, although these constructs were known to provide frequent transposition in other species. Also, no transposition was observed in later generations. In subsequent experiments, transposition was detected in lettuce calli using constructs that allowed selection for excision events. In these constructs, the neomycin phosphotransferase II gene was interrupted by either Ac or Ds. Excision was detected as the ability of callus to grow on kanamycin. Synthesis of the transposase from the cDNA of Ac expressed from the T-DNA 2' promoter resulted in more frequent excision of Ds than was observed with the wild-type Ac. No excision was observed with Ds in the absence of the transposase. The excision events were confirmed by amplification of the excision site by PCR followed by DNA sequencing. Excision and reintegration were also confirmed by Southern analysis. Ac/Ds is therefore capable of transposition in at least calli of lettuce.

The NEIL1 G83D germline DNA glycosylase variant induces genomic instability and cellular transformation

PubMed Central

Galick, Heather A.; Marsden, Carolyn G.; Kathe, Scott; Dragon, Julie A.; Volk, Lindsay; Nemec, Antonia A.; Wallace, Susan S.; Prakash, Aishwarya; Doublié, Sylvie; Sweasy, Joann B.

2017-01-01

Base excision repair (BER) is a key genome maintenance pathway. The NEIL1 DNA glycosylase recognizes oxidized bases, and likely removes damage in advance of the replication fork. The rs5745906 SNP of the NEIL1 gene is a rare human germline variant that encodes the NEIL1 G83D protein, which is devoid of DNA glycosylase activity. Here we show that expression of G83D NEIL1 in MCF10A immortalized but non-transformed mammary epithelial cells leads to replication fork stress. Upon treatment with hydrogen peroxide, we observe increased levels of stalled replication forks in cells expressing G83D NEIL1 versus cells expressing the wild-type (WT) protein. Double-strand breaks (DSBs) arise in G83D-expressing cells during the S and G2/M phases of the cell cycle. Interestingly, these breaks result in genomic instability in the form of high levels of chromosomal aberrations and micronuclei. Cells expressing G83D also grow in an anchorage independent manner, suggesting that the genomic instability results in a carcinogenic phenotype. Our results are consistent with the idea that an inability to remove oxidative damage in an efficient manner at the replication fork leads to genomic instability and mutagenesis. We suggest that individuals who harbor the G83D NEIL1 variant face an increased risk for human cancer. PMID:29156764

Uniform Free-Energy Profiles of the P-O Bond Formation and Cleavage Reactions Catalyzed by DNA Polymerases β and λ.

PubMed

Klvaňa, Martin; Bren, Urban; Florián, Jan

2016-12-29

Human X-family DNA polymerases β (Polβ) and λ (Polλ) catalyze the nucleotidyl-transfer reaction in the base excision repair pathway of the cellular DNA damage response. Using empirical valence bond and free-energy perturbation simulations, we explore the feasibility of various mechanisms for the deprotonation of the 3'-OH group of the primer DNA strand, and the subsequent formation and cleavage of P-O bonds in four Polβ, two truncated Polλ (tPolλ), and two tPolλ Loop1 mutant (tPolλΔL1) systems differing in the initial X-ray crystal structure and nascent base pair. The average calculated activation free energies of 14, 18, and 22 kcal mol -1 for Polβ, tPolλ, and tPolλΔL1, respectively, reproduce the trend in the observed catalytic rate constants. The most feasible reaction pathway consists of two successive steps: specific base (SB) proton transfer followed by rate-limiting concerted formation and cleavage of the P-O bonds. We identify linear free-energy relationships (LFERs) which show that the differences in the overall activation and reaction free energies among the eight studied systems are determined by the reaction free energy of the SB proton transfer. We discuss the implications of the LFERs and suggest pK a of the 3'-OH group as a predictor of the catalytic rate of X-family DNA polymerases.

Uniform Free-Energy Profiles of the P–O Bond Formation and Cleavage Reactions Catalyzed by DNA Polymerases β and λ

PubMed Central

2016-01-01

Human X-family DNA polymerases β (Polβ) and λ (Polλ) catalyze the nucleotidyl-transfer reaction in the base excision repair pathway of the cellular DNA damage response. Using empirical valence bond and free-energy perturbation simulations, we explore the feasibility of various mechanisms for the deprotonation of the 3′-OH group of the primer DNA strand, and the subsequent formation and cleavage of P–O bonds in four Polβ, two truncated Polλ (tPolλ), and two tPolλ Loop1 mutant (tPolλΔL1) systems differing in the initial X-ray crystal structure and nascent base pair. The average calculated activation free energies of 14, 18, and 22 kcal mol–1 for Polβ, tPolλ, and tPolλΔL1, respectively, reproduce the trend in the observed catalytic rate constants. The most feasible reaction pathway consists of two successive steps: specific base (SB) proton transfer followed by rate-limiting concerted formation and cleavage of the P–O bonds. We identify linear free-energy relationships (LFERs) which show that the differences in the overall activation and reaction free energies among the eight studied systems are determined by the reaction free energy of the SB proton transfer. We discuss the implications of the LFERs and suggest pKa of the 3′-OH group as a predictor of the catalytic rate of X-family DNA polymerases. PMID:27992186

Frequency of invasive cancer in surgically excised vulvar lesions with intraepithelial neoplasia (VIN 3).

PubMed

Husseinzadeh, N; Recinto, C

1999-04-01

The aim of this study was to determine the frequency of invasive cancer found from specimens removed by surgical excision on patients with diagnosis of VIN 3. Seventy-eight patients with biopsy-proven vulvar intraepithelial neoplasia 3 (VIN 3) were treated by surgical excision. Sixteen patients (20.5%) were found to have invasion in the excised surgical specimen. Superficial invasion was seen in 7 patients (9%), 9 were noted to have >1 mm invasion (11.5%), and 1 patient had in situ Paget's disease (1.3%). Surgical excision should be considered a preferable method in management of patients with VIN 3. Copyright 1999 Academic Press.

The effect of alcoholic beverage excise tax on alcohol-attributable injury mortalities.

PubMed

Son, Chong Hwan; Topyan, Kudret

2011-04-01

This study examines the effect of state excise taxes on different types of alcoholic beverages (spirits, wine, and beer) on alcohol-attributable injury mortalities--deaths caused by motor vehicle accidents, suicides, homicides, and falls--in the United States between 1995 and 2004, using state-level panel data. There is evidence that injury deaths attributable to alcohol respond differently to changes in state excise taxes on alcohol-specific beverages. This study examines the direct relationship between injury deaths and excise taxes without testing the degree of the association between excise taxes and alcohol consumption. The study finds that beer taxes are negatively related to motor vehicle accident mortality, while wine taxes are negatively associated with suicides and falls. The positive coefficient of the spirit taxes on falls implies a substitution effect between spirits and wine, suggesting that an increase in spirit tax will cause spirit buyers to purchase more wine. This study finds no evidence of a relationship between homicides and state excise taxes on alcohol. Thus, the study concludes that injury deaths attributable to alcohol respond differently to the excise taxes on different types of alcoholic beverages.

Re-excision rates after breast conserving surgery following the 2014 SSO-ASTRO guidelines.

PubMed

Heelan Gladden, Alicia A; Sams, Sharon; Gleisner, Ana; Finlayson, Christina; Kounalakis, Nicole; Hosokawa, Patrick; Brown, Regina; Chong, Tae; Mathes, David; Murphy, Colleen

2017-12-01

In 2014, SSO-ASTRO published guidelines which recommended "no ink on tumor" as adequate margins for patients undergoing breast conservation for invasive breast cancer. In 2016, new SSO-ASTRO-ASCO guidelines recommended 2 mm margins for DCIS. We evaluated whether these guidelines affected re-excision rates at our institution. Patients treated with breast conservation surgery from January 1, 2010-March 1, 2016 were identified. Re-excision rates, tumor characteristics, and presence of residual disease were recorded. The 2016 guidelines were retrospectively applied to the same cohort and expected re-excision rates calculated. Re-excision rates did not significantly decline before and after 2014 guideline adoption (11.9% before, 10.9% after; p = 0.65) or when the 2016 guidelines were retrospectively applied (8.4%; p = 0.10). The 2014 and 2016 guidelines had minimal impact on our re-excision rates, as most re-excisions were done for DCIS and 2016 guidelines supported our prior institutional practices of 2 mm margins for these patients. Copyright © 2017 Elsevier Inc. All rights reserved.

Subtalar Coalitions: Does the Morphology of the Subtalar Joint Involvement Influence Outcomes After Coalition Excision?

PubMed

Mahan, Susan T; Prete, Victoria I; Spencer, Samantha A; Kasser, James R; Bixby, Sarah D

Posteromedial subtalar (PMST) coalitions are a recently described anatomic subtype of tarsal coalitions. We compared with clinical patient-based outcomes of patients with PMST and standard middle facet (MF) coalitions who had undergone surgical excision of their coalition. The included patients had undergone surgical excision of a subtalar tarsal coalition, preoperative computed tomography (CT), and patient-based outcomes measures after surgery (including the American Orthopaedic Foot and Ankle Society [AOFAS] scale and University of California, Los Angeles [UCLA], activity score). Blinded analysis of the preoperative CT scan findings determined the presence of a standard MF versus a PMST coalition. The perioperative factors and postoperative outcomes between the MF and PMST coalitions were compared. A total of 51 feet (36 patients) were included. The mean follow-up duration was 2.6 years after surgery. Of the 51 feet, 15 (29.4%) had a PMST coalition and 36 (70.6%) had an MF coalition. No difference was found in the UCLA activity score; however, the mean AOFAS scale score was higher for patients with PMST (95.7) than for those with MF (86.5; p = .018). Of the patients with a PMST, none had foot pain limiting their activities at the final clinical follow-up visit. However, in the group with an MF subtalar coalition, 10 (27.8%) had ongoing foot pain limiting activity at the final follow-up visit (p = .024). Compared with MF subtalar tarsal coalitions, patients with PMST coalitions showed significantly improved clinical outcomes after excision. Preoperative identification of the facet morphology can improve patient counseling and expectations after surgery. Copyright © 2017 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

The Chromatin Remodeler Isw1 Prevents CAG Repeat Expansions During Transcription in Saccharomyces cerevisiae

PubMed Central

Koch, Melissa R.; House, Nealia C. M.; Cosetta, Casey M.; Jong, Robyn M.; Salomon, Christelle G.; Joyce, Cailin E.; Philips, Elliot A.; Su, Xiaofeng A.; Freudenreich, Catherine H.

2018-01-01

CAG/CTG trinucleotide repeats are unstable sequences that are difficult to replicate, repair, and transcribe due to their structure-forming nature. CAG repeats strongly position nucleosomes; however, little is known about the chromatin remodeling needed to prevent repeat instability. In a Saccharomyces cerevisiae model system with CAG repeats carried on a YAC, we discovered that the chromatin remodeler Isw1 is required to prevent CAG repeat expansions during transcription. CAG repeat expansions in the absence of Isw1 were dependent on both transcription-coupled repair (TCR) and base-excision repair (BER). Furthermore, isw1∆ mutants are sensitive to methyl methanesulfonate (MMS) and exhibit synergistic MMS sensitivity when combined with BER or TCR pathway mutants. We conclude that CAG expansions in the isw1∆ mutant occur during a transcription-coupled excision repair process that involves both TCR and BER pathways. We observed increased RNA polymerase II (RNAPII) occupancy at the CAG repeat when transcription of the repeat was induced, but RNAPII binding did not change in isw1∆ mutants, ruling out a role for Isw1 remodeling in RNAPII progression. However, nucleosome occupancy over a transcribed CAG tract was altered in isw1∆ mutants. Based on the known role of Isw1 in the reestablishment of nucleosomal spacing after transcription, we suggest that a defect in this function allows DNA structures to form within repetitive DNA tracts, resulting in inappropriate excision repair and repeat-length changes. These results establish a new function for Isw1 in directly maintaining the chromatin structure at the CAG repeat, thereby limiting expansions that can occur during transcription-coupled excision repair. PMID:29305386

Development of a long-term ovine model of cutaneous burn and smoke inhalation injury and the effects of early excision and skin autografting

PubMed Central

Yamamoto, Yusuke; Enkhbaatar, Perenlei; Sakurai, Hiroyuki; Rehberg, Sebastian; Asmussen, Sven; Ito, Hiroshi; Sousse, Linda E.; Cox, Robert A.; Deyo, Donald J.; Traber, Lillian D.; Traber, Maret G.; Herndon, David N.; Traber, Daniel L.

2013-01-01

Smoke inhalation injury frequently increases the risk of pneumonia and mortality in burn patients. The pathophysiology of acute lung injury secondary to burn and smoke inhalation is well studied, but long-term pulmonary function, especially the process of lung tissue healing following burn and smoke inhalation, has not been fully investigated. By contrast, early burn excision has become the standard of care in the management of major burn injury. While many clinical studies and small-animal experiments support the concept of early burn wound excision, and show improved survival and infectious outcomes, we have developed a new chronic ovine model of burn and smoke inhalation injury with early excision and skin grafting that can be used to investigate lung pathophysiology over a period of 3 weeks. Materials and methods Eighteen female sheep were surgically prepared for this study under isoflurane anesthesia. The animals were divided into three groups: an Early Excision group (20% TBSA, third-degree cutaneous burn and 36 breaths of cotton smoke followed by early excision and skin autografting at 24 h after injury, n = 6), a Control group (20% TBSA, third-degree cutaneous burn and 36 breaths of cotton smoke without early excision, n = 6) and a Sham group (no injury, no early excision, n = 6). After induced injury, all sheep were placed on a ventilator and fluid-resuscitated with Lactated Ringers solution (4 mL/% TBS/kg). At 24 h post-injury, early excision was carried out to fascia, and skin grafting with meshed autografts (20/1000 in., 1:4 ratio) was performed under isoflurane anesthesia. At 48 h post-injury, weaning from ventilator was begun if PaO2/FiO2 was above 250 and sheep were monitored for 3 weeks. Results At 96 h post-injury, all animals were weaned from ventilator. There are no significant differences in PaO2/FiO2 between Early Excision and Control groups at any points. All animals were survived for 3 weeks without infectious complication in Early Excision and Sham groups, whereas two out of six animals in the Control group had abscess in lung. The percentage of the wound healed surviving area (mean ± SD) was 74.7 ± 7.8% on 17 days post-surgery in the Early Excision group. Lung wet-to-dry weight ratio (mean ± SD) was significantly increased in the Early Excision group vs. Sham group (p < 0.05). The calculated net fluid balance significantly increased in the early excision compared to those seen in the Sham and Control groups. Plasma protein, oncotic pressure, hematocrit of % baseline, hemoglobin of % baseline, white blood cell and neutrophil were significantly decreased in the Early Excision group vs. Control group. Conclusions The early excision model closely resembles practice in a clinical setting and allows long-term observations of pulmonary function following burn and smoke inhalation injury. Further studies are warranted to assess lung tissue scarring and measuring collagen deposition, lung compliance and diffusion capacity. PMID:22459154

Detection of damaged DNA bases by DNA glycosylase enzymes.

PubMed

Friedman, Joshua I; Stivers, James T

2010-06-22

A fundamental and shared process in all forms of life is the use of DNA glycosylase enzymes to excise rare damaged bases from genomic DNA. Without such enzymes, the highly ordered primary sequences of genes would rapidly deteriorate. Recent structural and biophysical studies are beginning to reveal a fascinating multistep mechanism for damaged base detection that begins with short-range sliding of the glycosylase along the DNA chain in a distinct conformation we call the search complex (SC). Sliding is frequently punctuated by the formation of a transient "interrogation" complex (IC) where the enzyme extrahelically inspects both normal and damaged bases in an exosite pocket that is distant from the active site. When normal bases are presented in the exosite, the IC rapidly collapses back to the SC, while a damaged base will efficiently partition forward into the active site to form the catalytically competent excision complex (EC). Here we review the unique problems associated with enzymatic detection of rare damaged DNA bases in the genome and emphasize how each complex must have specific dynamic properties that are tuned to optimize the rate and efficiency of damage site location.

Cost-effectiveness of risk stratified followup after urethral reconstruction: a decision analysis.

PubMed

Belsante, Michael J; Zhao, Lee C; Hudak, Steven J; Lotan, Yair; Morey, Allen F

2013-10-01

We propose a novel risk stratified followup protocol for use after urethroplasty and explore potential cost savings. Decision analysis was performed comparing a symptom based, risk stratified protocol for patients undergoing excision and primary anastomosis urethroplasty vs a standard regimen of close followup for urethroplasty. Model assumptions included that excision and primary anastomosis has a 94% success rate, 11% of patients with successful urethroplasty had persistent lower urinary tract symptoms requiring cystoscopic evaluation, patients in whom treatment failed undergo urethrotomy and patients with recurrence on symptom based surveillance have a delayed diagnosis requiring suprapubic tube drainage. The Nationwide Inpatient Sample from 2010 was queried to identify the number of urethroplasties performed per year in the United States. Costs were obtained based on Medicare reimbursement rates. The 5-year cost of a symptom based, risk stratified followup protocol is $430 per patient vs $2,827 per patient using standard close followup practice. An estimated 7,761 urethroplasties were performed in the United States in 2010. Assuming that 60% were excision and primary anastomosis, and with more than 5 years of followup, the risk stratified protocol was projected to yield an estimated savings of $11,165,130. Sensitivity analysis showed that the symptom based, risk stratified followup protocol was far more cost-effective than standard close followup in all settings. Less than 1% of patients would be expected to have an asymptomatic recurrence using the risk stratified followup protocol. A risk stratified, symptom based approach to urethroplasty followup would produce a significant reduction in health care costs while decreasing unnecessary followup visits, invasive testing and radiation exposure. Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Negative pressure wound therapy, staged excision and definitive closure with split-thickness skin graft for axillary hidradenitis suppurativa: a retrospective study.

PubMed

Pearce, F B; Richardson, K A

2017-01-02

Bilateral axillary hidradenitis is a chronic, suppurative, and scarring disease that is most effectively treated by complete excision of all hair-bearing tissues. We assessed our staged procedure for excision and placement of a split-thickness skin graft for bilateral axillary hidradenitis in terms of costs, outcomes, and timing of excision. An IRB approved retrospective case analysis was performed on patients that underwent bilateral axillary hidradenitis skin excision with eventual placement of split-thickness skin grafting using the current LSUHSC/University Health hidradenitis surgical treatment protocol. Using ICD-9 codes (705.83) and CPT codes (11041, 11042, 11451, 11600, 11601, 11602, 11603, 11604) we reviewed cases performed at our institution from 1 January 2008 to 24 Febuary 2014 and we selected patients based on bilateral axillary involvement (alone) and >1 year history of active disease. Patients were excluded if resection of tissue encompassed regions outside of the immediately adjacent axillary. A total of seven patients matching criteria for bilateral axillary hidradenitis were selected for analysis. Clinical course, cost and surgical techniques were assessed. Of the seven patients, six required admission throughout their treatment due to lack of funding making use of negative pressure wound therapy at home not possible. These patients stayed an average of 10 days with a mean hospital charge of $35,178 and a mean hospital provider charge of $10,019. No recurrence was demonstrated. All patients attained full range of motion, post grafting. No patient required a further operation due to graft failure. Split-thickness skin grafting without use of bilayer dermal regenerative templates yielded definitive results with acceptable cosmesis and functionality, without the added cost of treatments such as a bilayer dermal regenerative template.

Sphincter-sparing local excision and hypofractionated radiation therapy for anorectal melanoma: a 20-year experience.

PubMed

Kelly, Patrick; Zagars, Gunar K; Cormier, Jancie N; Ross, Merrick I; Guadagnolo, B Ashleigh

2011-10-15

Anorectal melanoma is a rare disease with a poor prognosis. Because survival is determined by distant failure, many centers have adopted sphincter-sparing excision for primary tumor control. However, this approach is associated with high rates of local failure (∼50%). In this study, the authors report their 20-year experience with sphincter-sparing excision combined with radiation therapy (RT) for the treatment of localized anorectal melanoma. The authors reviewed the records of 54 patients with localized anorectal melanoma who were treated at the University of Texas MD Anderson Cancer Center from 1989 to 2008. All patients underwent definitive local excision with or without sentinel lymph node biopsy or lymph node dissection. RT (25-36 grays in 5-6 fractions) was delivered to extended fields that targeted the primary site and draining pelvic/inguinal lymphatics in 39 patients and to limited fields that targeted only the primary site in 15 patients. The 5-year rates of local control (LC), lymph node control (NC), and sphincter preservation were 82%, 88%, and 96%, respectively. However, because of the high rate of distant metastasis, the overall survival (OS) rate at 5 years was only 30%. Although there were no significant differences in LC, NC, or OS based on RT field extent, patients who received extended-field RT had higher rates of lymphedema than patients who received limited-field RT. The current results indicated that combined sphincter-sparing local excision and RT is a well tolerated approach that provides effective LC for patients with anorectal melanoma. Inclusion of the inguinal lymph node basins in the RT fields did not improve outcomes and was associated with an increased risk of lymphedema. Copyright © 2011 American Cancer Society.

Excision Repair-Initiated Enzyme-Assisted Bicyclic Cascade Signal Amplification for Ultrasensitive Detection of Uracil-DNA Glycosylase.

PubMed

Wang, Li-Juan; Ren, Ming; Zhang, Qianyi; Tang, Bo; Zhang, Chun-Yang

2017-04-18

Uracil-DNA glycosylase (UDG) is an important base excision repair (BER) enzyme responsible for the repair of uracil-induced DNA lesion and the maintenance of genomic integrity, while the aberrant expression of UDG is associated with a variety of cancers. Thus, the accurate detection of UDG activity is essential to biomedical research and clinical diagnosis. Here, we develop a fluorescent method for ultrasensitive detection of UDG activity using excision repair-initiated enzyme-assisted bicyclic cascade signal amplification. This assay involves (1) UDG-actuated uracil-excision repair, (2) excision repair-initiated nicking enzyme-mediated isothermal exponential amplification, (3) ribonuclease H (RNase H)-induced hydrolysis of signal probes for generating fluorescence signal. The presence of UDG enables the removal of uracil from U·A pairs and generates an apurinic/apyrimidinic (AP) site. Endonuclease IV (Endo IV) subsequently cleaves the AP site, resulting in the break of DNA substrate. The cleaved DNA substrate functions as both a primer and a template to initiate isothermal exponential amplification, producing a large number of triggers. The resultant trigger may selectively hybridize with the signal probe which is modified with FAM and BHQ1, forming a RNA-DNA heterogeneous duplex. The subsequent hydrolysis of RNA-DNA duplex by RNase H leads to the generation of fluorescence signal. This assay exhibits ultrahigh sensitivity with a detection limit of 0.0001 U/mL, and it can even measure UDG activity at the single-cell level. Moreover, this method can be applied for the measurement of kinetic parameters and the screening of inhibitors, thereby providing a powerful tool for DNA repair enzyme-related biomedical research and clinical diagnosis.

Reasons for excision of skin tumors: a one-year prospective study in a tertiary skin cancer unit.

PubMed

Lallas, Aimilios; Longo, Caterina; Moscarella, Elvira; Lombardi, Mara; Specchio, Francesca; Raucci, Margherita; Zalaudek, Iris; Argenziano, Giuseppe

2015-01-01

Biopsies and surgical excisions represent routine procedures in clinical settings dealing with skin cancer. To evaluate the impact of clinical examination, dermoscopy, reflectance confocal microscopy and digital monitoring on the decision to excise or biopsy a lesion in routine practice. Patients scheduled for biopsy or excision of a skin lesion were prospectively enrolled. The expert dermatologist was asked to select the main factor that prompted him/her to excise or biopsy the lesion. The most common reason for melanoma excision was clinical and dermoscopic morphology (70.3%), followed by dermoscopy (11.4%), monitoring (8.9%) and clinical context (8.2%). Most basal and squamous cell carcinomas were recognized both clinically and dermoscopically, while 18.6 and 15.0%, respectively, could only be detected with dermoscopic examination. Each part of the clinical examination has a contributory role in the diagnosis of melanoma and other skin cancers.

En bloc excision of a dermal sinus tract.

PubMed

Coumans, Jean-Valery; Walcott, Brian P; Redjal, Navid; Kahle, Kristopher T; Nahed, Brian V

2011-04-01

Dermal sinus tracts are a form of spinal dysraphism that arises from a failure of dysjunction early in embryogenesis. They are diagnosed in pediatric patients and who present with a dimple, infection, or neurologic deficit. The tract is surgically excised en bloc to avoid contamination from the tract, which harbors bacteria. However, dermal sinus tracts typically terminate intradurally, rendering their en bloc excision difficult. To avoid entering the tract, allowing for an en bloc excision, we modified the usual technique employed for accessing the spinal intradural space. An en bloc excision of the dermal sinus tract was successfully performed. The patient recovered from the procedure neurologically intact and her postoperative course was uncomplicated. We conclude that en bloc excision of a dermal sinus tract down to the intradural space is feasible with modifications to standard operative technique. Copyright © 2010 Elsevier Ltd. All rights reserved.

Silencing Inhibits Cre-Mediated Recombination of the Z/AP and Z/EG Reporters in Adult Cells

PubMed Central

Long, Michael A.; Rossi, Fabio M. V.

2009-01-01

Background The Cre-loxP system has been used to enable tissue specific activation, inactivation and mutation of many genes in vivo and has thereby greatly facilitated the genetic dissection of several cellular and developmental processes. In such studies, Cre-reporter strains, which carry a Cre-activated marker gene, are frequently utilized to validate the expression profile of Cre transgenes, to act as a surrogate marker for excision of a second allele, and to irreversibly label cells for lineage tracing experiments. Principal Findings We have studied three commonly used Cre-reporter strains, Z/AP, Z/EG and R26R-EYFP and have demonstrated that although each reporter can be reliably activated by Cre during early development, exposure to Cre in adult hematopoietic cells results in a much lower frequency of marker-positive cells in the Z/AP or Z/EG strains than in the R26R-EYFP strain. In marker negative cells derived from the Z/AP and Z/EG strains, the transgenic promoter is methylated and Cre-mediated recombination of the locus is inhibited. Conclusions These results show that the efficiency of Cre-mediated recombination is not only dependent on the genomic context of a given loxP-flanked sequence, but also on stochastic epigenetic mechanisms underlying transgene variegation. Furthermore, our data highlights the potential shortcomings of utilizing the Z/AP and Z/EG reporters as surrogate markers of excision or in lineage tracing experiments. PMID:19415111

Silencing inhibits Cre-mediated recombination of the Z/AP and Z/EG reporters in adult cells.

PubMed

Long, Michael A; Rossi, Fabio M V

2009-01-01

The Cre-loxP system has been used to enable tissue specific activation, inactivation and mutation of many genes in vivo and has thereby greatly facilitated the genetic dissection of several cellular and developmental processes. In such studies, Cre-reporter strains, which carry a Cre-activated marker gene, are frequently utilized to validate the expression profile of Cre transgenes, to act as a surrogate marker for excision of a second allele, and to irreversibly label cells for lineage tracing experiments. We have studied three commonly used Cre-reporter strains, Z/AP, Z/EG and R26R-EYFP and have demonstrated that although each reporter can be reliably activated by Cre during early development, exposure to Cre in adult hematopoietic cells results in a much lower frequency of marker-positive cells in the Z/AP or Z/EG strains than in the R26R-EYFP strain. In marker negative cells derived from the Z/AP and Z/EG strains, the transgenic promoter is methylated and Cre-mediated recombination of the locus is inhibited. These results show that the efficiency of Cre-mediated recombination is not only dependent on the genomic context of a given loxP-flanked sequence, but also on stochastic epigenetic mechanisms underlying transgene variegation. Furthermore, our data highlights the potential shortcomings of utilizing the Z/AP and Z/EG reporters as surrogate markers of excision or in lineage tracing experiments.

Intraoperative diagnosis of nonpigmented nail tumours with ex vivo fluorescence confocal microscopy: 10 cases.

PubMed

Debarbieux, S; Gaspar, R; Depaepe, L; Dalle, S; Balme, B; Thomas, L

2015-04-01

Ex vivo fluorescence confocal microscopy (FCM) permits real-time imaging of freshly excised skin tissues. Its usefulness as a time-sparing alternative to frozen sections in Mohs surgery of basal cell carcinoma is well documented. The purpose of this study was to describe the ex vivo FCM features of a series of benign and malignant nonpigmented tumours of the nail unit, and to correlate them with conventional histopathology. Nail apparatus tumours from 10 patients were imaged during surgical exploration using ex vivo FCM after immersion in acridine orange. Confocal mosaics of the freshly performed biopsies were evaluated in real time and retrospectively compared with haematoxylin and eosin sections. Our series included two invasive epithelial tumours (Group 1), four in situ or minimally invasive squamous cell carcinomas (SCC) (Group 2), three benign epithelial tumours (Group 3) and one nodular melanoma (Group 4). The correlation was excellent for malignant epithelial tumours exhibiting marked cytological and architectural atypias (Bowen disease, invasive SCC and onycholemmal carcinoma). Onychomatricomas exhibited a very peculiar aspect with densely cellular papillae. The correlation was less favourable for minimally invasive well-differentiated SCCs with slight cytological atypias. The correlation was poor for our case of amelanotic invasive subungual melanoma. Ex vivo FCM could be a useful tool to shorten management of nonpigmented nail tumours: in the case of a malignant tumour, it could indeed lead to performing wide excision during the same surgical procedure and possibly assessing the surgical margins. © 2014 British Association of Dermatologists.

Stratified Mucin-Producing Intraepithelial Lesion of the Cervix: Subtle Features Not to Be Missed.

PubMed

Schwock, Joerg; Ko, Hyang Mi; Dubé, Valérie; Rouzbahman, Marjan; Cesari, Matthew; Ghorab, Zeina; Geddie, William R

2016-01-01

Stratified mucin-producing intraepithelial lesion (SMILE) is an uncommon premalignant lesion of the uterine cervix. A detailed examination of preinvasive SMILE cases including a comparison of the cytologic features with usual-type adenocarcinoma in situ (AIS) and human papillomavirus (HPV) genotyping was performed. Excisions and preceding Papanicolaou (Pap) tests were retrieved from the files of 2 tertiary care centers. Histologic review estimated the lesional SMILE proportion. Pap tests were reviewed and assessed for architectural, cellular and background features. Cobas® HPV test was performed. 13 cases were identified. Mean/median patient age was 35/33 years (range 23-51 years). Concurrent high-grade squamous intraepithelial lesion was found in 10/13 (77%) and AIS in 8/13 (62%) cases. In 6 cases, SMILE was dominant (≥50%) and represented in 5/6 corresponding Pap tests. Cytology interpretations differed more often in the SMILE-dominant group (p < 0.05). SMILE and AIS had overlapping features. Feathering and prominent nucleoli were absent in SMILE. HPV DNA was detected in all 12 cases tested. HPV 18 was most common (7/12). Excisions with positive/suspicious margins were reported in 5/6 SMILE-dominant versus 3/7 nondominant cases. SMILE is best considered as an AIS variant for cytologic, etiologic and management purposes. Cytologic features overlap with AIS, but are more subtle and easily missed. HPV testing may play a role in facilitating SMILE detection. © 2016 S. Karger AG, Basel.

Benign Intraductal Papilloma without Atypia on Core Needle Biopsy Has a Low Rate of Upgrading to Malignancy after Excision.

PubMed

Han, Song-Hee; Kim, Milim; Chung, Yul Ri; Yun, Bo La; Jang, Mijung; Kim, Sun Mi; Kang, Eunyoung; Kim, Eun-Kyu; Park, So Yeon

2018-03-01

The management of benign intraductal papilloma (IDP) without atypia diagnosed on core needle biopsy (CNB) remains controversial. This study was performed to evaluate the rate of upgrading to malignancy or high-risk lesions after excision and to identify factors associated with upgrading using a large series of benign IDP cases without atypia. We included patients who were diagnosed as having benign IDP without atypia on CNB and underwent surgical or vacuum-assisted excision between 2010 and 2015. We analyzed the clinical, radiologic, and histopathologic features of IDPs that were upgraded to malignancy or high-risk lesions after excision. A total of 511 benign IDPs without atypia diagnosed via CNB were identified, of which 398 cases were treated with excision. After reviewing these cases, four cases of high-risk lesions in adjacent tissue on CNB, two cases which were revealed as papilloma with atypia, and nine cases of malignancy in the same breast were excluded. In the remaining 383 cases, the rate of upgrading to malignancy and high-risk lesions after excision was 0.8% and 4.4%, respectively. The presence of concurrent contralateral breast cancer, the presence of symptoms, and multifocality were factors significantly associated with upgrading to malignancy on subsequent excision. Surgical excision rather than vacuum-assisted excision was significantly associated with upgrading to high-risk lesions or malignancy. The rate of upgrading to malignancy for benign IDP without atypia was very low, suggesting that close clinical and radiologic observation may be sufficient for patients with benign IDP without atypia on CNB under proper settings.

Covalent trapping of human DNA polymerase beta by the oxidative DNA lesion 2-deoxyribonolactone.

PubMed

DeMott, Michael S; Beyret, Ergin; Wong, Donny; Bales, Brian C; Hwang, Jae-Taeg; Greenberg, Marc M; Demple, Bruce

2002-03-08

Oxidized abasic residues in DNA constitute a major class of radiation and oxidative damage. Free radical attack on the nucleotidyl C-1' carbon yields 2-deoxyribonolactone (dL) as a significant lesion. Although dL residues are efficiently incised by the main human abasic endonuclease enzyme Ape1, we show here that subsequent excision by human DNA polymerase beta is impaired at dL compared with unmodified abasic sites. This inhibition is accompanied by accumulation of a protein-DNA cross-link not observed in reactions of polymerase beta with unmodified abasic sites, although a similar form can be trapped by reduction with sodium borohydride. The formation of the stably cross-linked species with dL depends on the polymerase lysine 72 residue, which forms a Schiff base with the C-1 aldehyde during excision of an unmodified abasic site. In the case of a dL residue, attack on the lactone C-1 by lysine 72 proceeds more slowly and evidently produces an amide linkage, which resists further processing. Consequently dL residues may not be readily repaired by "short-patch" base excision repair but instead function as suicide substrates in the formation of protein-DNA cross-links that may require alternative modes of repair.

Strand displacement synthesis by yeast DNA polymerase ε

PubMed Central

Ganai, Rais A.; Zhang, Xiao-Ping; Heyer, Wolf-Dietrich; Johansson, Erik

2016-01-01

DNA polymerase ε (Pol ε) is a replicative DNA polymerase with an associated 3′–5′ exonuclease activity. Here, we explored the capacity of Pol ε to perform strand displacement synthesis, a process that influences many DNA transactions in vivo. We found that Pol ε is unable to carry out extended strand displacement synthesis unless its 3′–5′ exonuclease activity is removed. However, the wild-type Pol ε holoenzyme efficiently displaced one nucleotide when encountering double-stranded DNA after filling a gap or nicked DNA. A flap, mimicking a D-loop or a hairpin structure, on the 5′ end of the blocking primer inhibited Pol ε from synthesizing DNA up to the fork junction. This inhibition was observed for Pol ε but not with Pol δ, RB69 gp43 or Pol η. Neither was Pol ε able to extend a D-loop in reconstitution experiments. Finally, we show that the observed strand displacement synthesis by exonuclease-deficient Pol ε is distributive. Our results suggest that Pol ε is unable to extend the invading strand in D-loops during homologous recombination or to add more than two nucleotides during long-patch base excision repair. Our results support the hypothesis that Pol ε participates in short-patch base excision repair and ribonucleotide excision repair. PMID:27325747

Primary surgical excision for pediatric orbital capillary hemangioma.

PubMed

Krema, Hatem

2015-05-01

We report the technique and outcome of surgical excision of subcutaneous orbital capillary hemangioma causing eye globe displacement in two children. Primary surgical excision was performed with blunt dissection along the tumor walls using a cotton-tipped applicator as the dissecting tool with simultaneous outward gentle traction on the tumor wall. Despite the deep and extensive orbital involvement, complete excision of the hemangiomas was achievable with this technique, which permitted excellent visualization of the surgical planes throughout the procedures. Deep and extensive pediatric orbital capillary hemangioma can be surgically excised with the suggested technique, which obviates the need for intralesional or systemic medical therapy, yielding optimal cosmetic and functional outcomes, shortly after surgery.

Pilonidal sinus disease surgery in children: the first study to compare crystallized phenol application to primary excision and closure.

PubMed

Ates, Ufuk; Ergun, Ergun; Gollu, Gulnur; Sozduyar, Sumeyye; Kologlu, Meltem; Cakmak, Murat; Dindar, Huseyin; Yagmurlu, Aydin

2018-03-01

Pilonidal sinus (PS) is an infectious and inflammatory disease of sacrococcygeal region. Current methods include; surgical excision with/without suturing the defect, rhomboid excision and flap and chemical substance application. In this study, crystallized phenol application was compared to excision and primary closure. This retrospective study included pediatric patients with PS who were treated with excision and primer closure technique and phenol application. The patients' medical data were analyzed retrospectively. This study included 117 patients with PS. There were 52 girls (44%) and 65 boys (56%). Mean age of children was 15.6 (12-20) years. Excision and primary closure were applied to 77 patients (66%) and phenol was applied to 40 patients (34%). The children in phenol group were discharged on the operation day; mean hospitalization time in the excision and primary closure group was 2.7 (1-14) days. Mean follow up was 44.6 (8-82) months for primary excision and closure group and 8.1 (1-19) months for phenol group. Although many surgical and non-surgical treatment modalities have been described for PS, the optimal one remains unknown. Limited with the retrospective nature of the data, crystallized phenol application seems a feasible minimal invasive alternative to primary closure of PS with lower recurrence and complication rates in children. Level III. Copyright © 2017 Elsevier Inc. All rights reserved.

The Management Strategy of Benign Solitary Intraductal Papilloma on Breast Core Biopsy.

PubMed

Ko, Dayoung; Kang, Eunyoung; Park, So Yeon; Kim, Sun Mi; Jang, Mijung; Yun, Bo La; Chae, Sumin; Jang, Yerang; Kim, Hye Jin; Kim, Sung-Won; Kim, Eun-Kyu

2017-08-01

Intraductal papilloma (IDP) is well-known as one of the common benign breast lesions requiring excision. However, treatment of IDP without atypia is controversial. The aim of our study was to determine the proper management of solitary IDP by core needle biopsy (CNB). We retrospectively reviewed patients with solitary IDP confirmed by CNB from March 2003 to March 2015. We collected data about final pathology after excision, as well as clinical, histologic, and radiologic findings at initial diagnosis. The final pathology was categorized as benign or malignant. We evaluated the rate of upgrade to malignancy and factors associated with malignancy. We identified 405 patients who presented benign solitary IDP by CNB. The mean age was 46.1 years (range, 15-86 years). In total, 135 patients underwent surgical excision, and 211 underwent vacuum-assisted excision. Of 346 patients, malignant lesions were found in 8 patients (2.3%): 7 underwent surgical excision, and 1 underwent vacuum-assisted excision. Only the size of IDP was significantly associated with cancer upgrade (P = .003). Our study shows that overall malignancy upgrade rate of benign solitary IDP after excision is very low (2.3%). Even when the size of IDP was less than 1 cm, the upgrade rate to cancer was only 0.9%. Therefore, for patients with small solitary IDP, we recommend close follow-up with ultrasound instead of excision. Copyright © 2017 Elsevier Inc. All rights reserved.

Germinal and Somatic Activity of the Maize Element Activator (Ac) in Arabidopsis

PubMed Central

Keller, J.; Lim, E.; James-Jr., D. W.; Dooner, H. K.

1992-01-01

We have investigated the germinal and somatic activity of the maize Activator (Ac) element in Arabidopsis with the objective of developing an efficient transposon-based system for gene isolation in that plant. Transposition activity was assayed with a chimeric marker that consists of the cauliflower mosaic virus 35S promoter and a bacterial streptomycin phosphotransferase gene (SPT). Somatic activity was detected in seedlings germinated on plates containing streptomycin as green-resistant sectors against a background of white-sensitive cells. Germinal excisions resulted in fully green seedlings. The transposition frequency was extremely low when a single copy of the transposon was present, but appeared to increase with an increase in Ac copy number. Plants that were selected as variegated produced an increased number of green progeny. The methylation state of the Ac elements in lines with either low or high levels of excision was assessed by restriction analysis. No difference was found between these lines, indicating that the degree of methylation did not contribute to the level of Ac activity. Germinal excision events were analyzed molecularly and shown to carry reinserted transposons in about 50% of the cases. In several instances, streptomycin-resistant siblings carried the same transposed Ac element, indicating that excision had occurred prior to meiosis in the parent. We discuss parameters that need to be considered to optimize the use of Ac as a transposon tag in Arabidopsis. PMID:1322854

Comparing initial diagnostic excision biopsy of cutaneous malignant melanoma in primary versus secondary care: A study of Irish National data.

PubMed

Doherty, Sarah M; Jackman, Louise M; Kirwan, John F; Dunne, Deirdre; O'Connor, Kieran G; Rouse, John M

2016-12-01

The incidence of melanoma is rising worldwide. Current Irish guidelines from the National Cancer Control Programme state suspicious pigmented lesions should not be removed in primary care. There are conflicting guidelines and research advising who should remove possible melanomas. To determine whether initial diagnostic excision biopsy of cutaneous malignant melanoma in primary versus secondary care leads to poorer survival. Analysis of data comprising 7116 cases of cutaneous malignant melanoma from the National Cancer Registry Ireland between January 2002 and December 2011. Single predictor variables were examined by the chi-square or Mann-Whitney U test. The effects of single predictor variables on survival were examined by Cox proportionate hazards modelling and a multivariate Cox model of survival based on excision in a non-hospital setting versus hospital setting was derived with adjusted and unadjusted hazard ratios. Over a 10-year period 8.5% of melanomas in Ireland were removed in a non-hospital setting. When comparing melanoma death between the hospital and non-hospital groups, the adjusted hazard ratio was 1.56 (95%CI: 1.08-2.26); (P = .02), indicating a non-inferior outcome for the melanoma cases initially treated in the non-hospital group, after adjustment for significant covariates. This study suggests that initial excision biopsy carried out in general practice does not lead to a poorer outcome. [Box: see text].

A rare case of atypical pleomorphic adenoma arising from periocular ectopic lacrimal gland.

PubMed

Wajda, Brynn N; Mancini, Ronald; Evers, Bret; Nick Hogan, R

2018-06-23

To describe features of atypical pleomorphic adenoma, a rare clinical entity, particularly when found in ectopic periocular lacrimal gland tissue. Case report of biopsy-confirmed periocular atypical pleomorphic adenoma. A 35-year-old female presented with a unique orbital lesion found to be ectopic lacrimal gland demonstrating atypical pleomorphic adenoma on formal histopathologic review. Pleomorphic adenoma is pathologically characterized as an epithelial lesion intermixed with mesenchymal elements. It is further classified as atypical with the presence of features such as hypercellularity, regions of necrosis or hyalinization, cellular dysplasia, capsular violation, and malignant characteristics without frank local extension or distant metastases. Due to its rarity, the natural history and prognosis of atypical pleomorphic adenoma is unclear. Physicians need to recognize this entity, and complete surgical excision with strict follow-up regimens are likely warranted.

Structure and specificity of FEN-1 from Methanopyrus kandleri

DOE PAGES

Shah, Santosh; Dunten, Pete; Stiteler, Amanda; ...

2014-11-18

DNA repair is fundamental to genome stability and is found in all three domains of life. However, many archaeal species, such as Methanopyrus kandleri, contain only a subset of the eukaryotic nucleotide excision repair (NER) homologues, and those present often contain significant differences compared to their eukaryotic homologues. To clarify the role of the NER XPG-like protein Mk0566 from M. kandleri, its biochemical activity and three dimensional structure were investigated. Ultimately, we found both to be more similar to human FEN-1 than human XPG, suggesting a biological role in replication and long-patch base excision repair rather than in NER.

The Extract of Lycium depressum Stocks Enhances Wound Healing in Streptozotocin-Induced Diabetic Rats.

PubMed

Naji, Siamak; Zarei, Leila; Pourjabali, Masoumeh; Mohammadi, Rahim

2017-06-01

In diabetes, impaired wound healing and other tissue abnormalities are considered major concerns. The aim of the present study was to assess the wound-healing activity of methanolic extracts of the extract of Lycium depressum leaves. A total of 60 healthy male Wistar diabetic rats weighing approximately 160 to 180 g and 7 weeks of age were randomized into 10 groups for incision and excision wound models: sham surgery group (SHAM), including creation of wounds and no treatment; base formulation group (FG) with creation of wounds and application of base formulation ointment; treatment group 1 (TG1) with 1 g of powder extract of the plant material in ointment; treatment group 2 (TG2) with 2 g; and treatment group 4 (TG3) with 4 g of powder extract of the plant material in ointment. A wound was induced by an excision- and incision-based wound model in male rats. The mature green leaves of L depressum were collected and authenticated. Extractions of dried leaves were carried out. For wound-healing activity, the extracts were applied topically in the form of ointment and compared with control groups. The healing of the wound was assessed based on excision, incision, hydroxyproline estimation, and biomechanical and biochemical studies. The extract of L depressum leaves enhanced wound contraction, decreased epithelialization time, increased hydroxyproline content, and improved mechanical indices and histological characteristics in treatment groups compared with SHAM and FG ( P < .05). These findings permit the conclusion the extract of L depressum benefits parameters of wound healing in a diabetes induced model.

Method and device for intraoperative imaging of lumpectomy specimens to provide feedback to breast surgeon for prompt re-excision during the same procedure

NASA Astrophysics Data System (ADS)

Krol, Andrzej; Hemingway, Susan; Kort, Kara; de la Rosa, Gustavo; Adhikary, Ravi; Masrani, Deepa; Feiglin, David; O'Connell, Avice; Nagarajan, Mahesh; Yang, Chien-Chun; Wismüller, Axel

2014-03-01

Breast conserving therapy (BCT) of breast cancer is now widely accepted due to improved cosmetic outcome and improved patients' quality of life. One of the critical issues in performing breast-conserving surgery is trying to achieve microscopically clear surgical margins while maintaining excellent cosmesis. Unfortunately, unacceptably close or positive surgical margins occur in at least 20-25% of all patients undergoing BCT requiring repeat surgical excision days or weeks later, as permanent histopathology routinely takes days to complete. Our aim is to develop a better method for intraoperative imaging of non-palpable breast malignancies excised by wire or needle localization. Providing non-deformed three dimensional imaging of the excised breast tissue should allow more accurate assessment of tumor margins and consequently allow further excision at the time of initial surgery thus limiting the enormous financial and emotional burden of additional surgery. We have designed and constructed a device that allows preservation of the excised breast tissue in its natural anatomic position relative to the breast as it is imaged to assess adequate excision. We performed initial tests with needle-guided lumpectomy specimens using micro-CT and digital breast tomosynthesis (DBT). Our device consists of a plastic sphere inside a cylindrical holder. The surgeon inserts a freshly excised piece of breast tissue into the sphere and matches its anatomic orientation with the fiducial markers on the sphere. A custom-shaped foam is placed inside the sphere to prevent specimen deformation due to gravity. DBT followed by micro-CT images of the specimen were obtained. We confirmed that our device preserved spatial orientation of the excised breast tissue and that the location error was lower than 10mm and 10 degrees. The initial obtained results indicate that breast lesions containing microcalcifications allow a good 3D imaging of margins providing immediate intraoperative feedback for further excision as needed at the initial operation.

Three surgical planes identified in laparoscopic complete mesocolic excision for right-sided colon cancer.

PubMed

Zhu, Da-Jian; Chen, Xiao-Wu; OuYang, Man-Zhao; Lu, Yan

2016-01-12

Complete mesocolic excision provides a correct anatomical plane for colon cancer surgery. However, manifestation of the surgical plane during laparoscopic complete mesocolic excision versus in computed tomography images remains to be examined. Patients who underwent laparoscopic complete mesocolic excision for right-sided colon cancer underwent an abdominal computed tomography scan. The spatial relationship of the intraoperative surgical planes were examined, and then computed tomography reconstruction methods were applied. The resulting images were analyzed. In 44 right-sided colon cancer patients, the surgical plane for laparoscopic complete mesocolic excision was found to be composed of three surgical planes that were identified by computed tomography imaging with cross-sectional multiplanar reconstruction, maximum intensity projection, and volume reconstruction. For the operations performed, the mean bleeding volume was 73±32.3 ml and the mean number of harvested lymph nodes was 22±9.7. The follow-up period ranged from 6-40 months (mean 21.2), and only two patients had distant metastases. The laparoscopic complete mesocolic excision surgical plane for right-sided colon cancer is composed of three surgical planes. When these surgical planes were identified, laparoscopic complete mesocolic excision was a safe and effective procedure for the resection of colon cancer.

[Animal experiment comparison of the therapeutic efficacy of tumor excision with a scalpel or with a CO2 laser in subcutaneously implanted Lewis lung cancer].

PubMed

Mahn, H R; Nowak, C; Audring, H; Liebetruth, J; Lindenau, K F

1982-02-01

An animal experimental study was carried out in order to compare the therapeutical value of two different surgical methods for excising the subcutaneous implanted Lewis lung carcinoma - tumor excision with scalpel or with carbon dioxide laser. The radicalism of operation methods, the survival time, and the tumor local recurrences were performed. The therapeutic effectivity of tumor excision with the carbon dioxide laser is more favourable than the scalpel method.

Robotic assisted excision of a left ventricular myxoma.

PubMed

Hassan, Mohammed; Smith, J Michael

2012-01-01

We present a rare case of left ventricular myxoma discovered incidentally in an asymptomatic 16-year old male. The patient underwent the appropriate work-up and a robotic-assisted excision of the mass. The patient had an uneventful recovery and was discharged home at postoperative day 3. To our knowledge, this is the first case of robotic-assisted left ventricular myxoma excision in the literature. Robotic-assisted surgery of left ventricular myxomas is a safe and feasible method of excision.

Multiple schwannomas of the digital nerves and superficial radial nerve: two unusual cases of segmental schwannomatosis.

PubMed

Gosk, Jerzy; Gutkowska, Olga; Kuliński, Sebastian; Urban, Maciej; Hałoń, Agnieszka

2015-01-01

Two cases of segmental sporadic schwannomatosis characterized by unusual location of multiple schwannomas in digital nerves (case 1) and the superficial radial nerve (case 2) are described in this paper. In the first of the described cases, 6 tumours located at the base of the middle finger and in its distal portion were excised from both digital nerves. In the second case, 3 tumours located in the proximal 1/3 and halfway down the forearm were removed from the superficial radial nerve. In both cases, symptoms such as palpable tumour mass, pain, paraesthesias, and positive Tinel-Hoffman sign resolved after operative treatment. Final diagnoses were made based on histopathological examination results. In the second of the described cases, the largest of the excised lesions had features enabling diagnosis of a rare tumour type - ancient schwannoma.

Magnetic resonance imaging (MRI)-based indication for neoadjuvant treatment of rectal carcinoma and the surrogate endpoint CRM status.

PubMed

Strassburg, Joachim; Junginger, Theo; Trinh, Trong; Püttcher, Olaf; Oberholzer, Katja; Heald, Richard J; Hermanek, Paul

2008-11-01

Is it possible to reduce the frequency of neoadjuvant therapy for rectal carcinoma and nevertheless achieve a rate of more than 90% circumferential resection margin (CRM)-negative resection specimens by a novel concept of magnetic resonance imaging (MRI)-based therapy planning? One hundred eighty-one patients from Berlin and Mainz, Germany, with primary rectal carcinoma, without distant metastasis, underwent radical surgery with curative intention. Surgical procedures applied were anterior resection with total mesorectal excision (TME) or partial mesorectal excision (PME; PME for tumours of the upper rectum) or abdominoperineal excision with TME. With MRI selection of the highest-risk cases, neoadjuvant therapy was given to only 62 of 181 (34.3%). The rate of CRM-negative resection specimens on histology was 170 of 181 (93.9%) for all patients, and in Berlin, only 1 of 93 (1%) specimens was CRM-positive. Patients selected for primary surgery had CRM-negative specimens on histology in 114 of 119 (95.8%). Those selected for neoadjuvant therapy had a lower rate of clear margin: 56 of 62 (90%). By applying a MRI-based indication, the frequency of neoadjuvant treatment with its acute and late adverse effects can be reduced to 30-35% without reduction of pathologically CRM-negative resection specimens and, thus, without the danger of worsening the oncological long-term results. This concept should be confirmed in prospective multicentre observation studies with quality assurance of MRI, surgery and pathology.

Effect of Amalaki rasayana on DNA damage and repair in randomized aged human individuals.

PubMed

Vishwanatha, Udupi; Guruprasad, Kanive P; Gopinath, Puthiya M; Acharya, Raviraj V; Prasanna, Bokkasa V; Nayak, Jayakrishna; Ganesh, Rajeshwari; Rao, Jayalaxmi; Shree, Rashmi; Anchan, Suchitra; Raghu, Kothanahalli S; Joshi, Manjunath B; Paladhi, Puspendu; Varier, Panniampilly M; Muraleedharan, Kollath; Muraleedharan, Thrikovil S; Satyamoorthy, Kapaettu

2016-09-15

Preparations from Phyllanthus emblica called Amalaki rasayana is used in the Indian traditional medicinal system of Ayurveda for healthy living in elderly. The biological effects and its mechanisms are not fully understood. Since the diminishing DNA repair is the hallmark of ageing, we tested the influence of Amalaki rasayana on recognized DNA repair activities in healthy aged individuals. Amalaki rasayana was prepared fresh and healthy aged randomized human volunteers were administrated with either rasayana or placebo for 45 days strictly as per the traditional text. The DNA repair was analyzed in peripheral blood mononuclear cells before and after rasayana administration and after 45 days post-rasayana treatment regimen. UVC-induced DNA strand break repair (DSBR) based on extent of DNA unwinding by fluorometric analysis, nucleotide excision repair (NER) by flow cytometry and constitutive base excision repair (BER) by gap filling method were analyzed. Amalaki rasayana administration stably maintained/enhanced the DSBR in aged individuals. There were no adverse side effects. Further, subjects with different body mass index showed differential DNA strand break repair capacity. No change in unscheduled DNA synthesis during NER and BER was observed between the groups. Intake of Amalaki rasayana by aged individuals showed stable maintenance of DNA strand break repair without toxic effects. However, there was no change in nucleotide and base excision repair activities. Results warrant further studies on the effects of Amalaki rasayana on DSBR activities. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

A multistep damage recognition mechanism for global genomic nucleotide excision repair

PubMed Central

Sugasawa, Kaoru; Okamoto, Tomoko; Shimizu, Yuichiro; Masutani, Chikahide; Iwai, Shigenori; Hanaoka, Fumio

2001-01-01

A mammalian nucleotide excision repair (NER) factor, the XPC–HR23B complex, can specifically bind to certain DNA lesions and initiate the cell-free repair reaction. Here we describe a detailed analysis of its binding specificity using various DNA substrates, each containing a single defined lesion. A highly sensitive gel mobility shift assay revealed that XPC–HR23B specifically binds a small bubble structure with or without damaged bases, whereas dual incision takes place only when damage is present in the bubble. This is evidence that damage recognition for NER is accomplished through at least two steps; XPC–HR23B first binds to a site that has a DNA helix distortion, and then the presence of injured bases is verified prior to dual incision. Cyclobutane pyrimidine dimers (CPDs) were hardly recognized by XPC–HR23B, suggesting that additional factors may be required for CPD recognition. Although the presence of mismatched bases opposite a CPD potentiated XPC–HR23B binding, probably due to enhancement of the helix distortion, cell-free excision of such compound lesions was much more efficient than expected from the observed affinity for XPC–HR23B. This also suggests that additional factors and steps are required for the recognition of some types of lesions. A multistep mechanism of this sort may provide a molecular basis for ensuring the high level of damage discrimination that is required for global genomic NER. PMID:11238373

A multistep damage recognition mechanism for global genomic nucleotide excision repair.

PubMed

Sugasawa, K; Okamoto, T; Shimizu, Y; Masutani, C; Iwai, S; Hanaoka, F

2001-03-01

A mammalian nucleotide excision repair (NER) factor, the XPC-HR23B complex, can specifically bind to certain DNA lesions and initiate the cell-free repair reaction. Here we describe a detailed analysis of its binding specificity using various DNA substrates, each containing a single defined lesion. A highly sensitive gel mobility shift assay revealed that XPC-HR23B specifically binds a small bubble structure with or without damaged bases, whereas dual incision takes place only when damage is present in the bubble. This is evidence that damage recognition for NER is accomplished through at least two steps; XPC-HR23B first binds to a site that has a DNA helix distortion, and then the presence of injured bases is verified prior to dual incision. Cyclobutane pyrimidine dimers (CPDs) were hardly recognized by XPC-HR23B, suggesting that additional factors may be required for CPD recognition. Although the presence of mismatched bases opposite a CPD potentiated XPC-HR23B binding, probably due to enhancement of the helix distortion, cell-free excision of such compound lesions was much more efficient than expected from the observed affinity for XPC-HR23B. This also suggests that additional factors and steps are required for the recognition of some types of lesions. A multistep mechanism of this sort may provide a molecular basis for ensuring the high level of damage discrimination that is required for global genomic NER.

Clinical, biomechanical and morphological assessment of anterior cruciate ligament Kevlar®-based artificial prosthesis in rabbit model.

PubMed

de la Garza-Castro, Santiago; González-Rivera, Carlos E; Vílchez-Cavazos, Félix; Morales-Avalos, Rodolfo; Barrera-Flores, Francisco J; Elizondo-Omaña, Rodrigo E; Soto-Dominguez, Adolfo; Acosta-Olivo, Carlos; Mendoza-Lemus, Oscar F

2017-07-27

The aim of this study was to evaluate the clinical, biomechanical and morphological characteristics of a Kevlar®-based prosthetic ligament as a synthetic graft of the anterior cruciate ligament (ACL) in an experimental animal model in rabbits. A total of 27 knees of rabbits randomly divided into 3 groups (control, ACL excision and ACL replacement with a Kevlar® prosthesis) were analyzed using clinical, biomechanical and morphological tests at 6, 12 and 18 weeks postprocedure. The mean displacement in mechanical testing was 0.73 ± 0.06 mm, 1.58 ± 0.19 mm and 0.94 ± 0.20 mm for the control, ACL excision and ACL replacement with synthetic prosthesis groups, respectively. The results showed an improvement in the stability of the knee with the use of the Kevlar® synthetic prosthesis in the biomechanical testing (p<0.05) compared with rabbits that underwent ACL excision, in addition to displacements that were larger but comparable to that in the control group (p>0.05), between the replacement group and the control group. The histological study revealed a good morphological adaptation of the synthetic material to the knee. This study proposes a new animal model for the placement and evaluation of Kevlar®-based synthetic ACL implants. The studied prosthesis showed promising behavior in the clinical and biomechanical tests and in the histological analysis. This study lays the foundation for further basic and clinical studies of artificial ACL prostheses using this material.

Early post-operative weight loss after laparoscopic sleeve gastrectomy correlates with the volume of the excised stomach and not with that of the sleeve! Preliminary data from a multi-detector computed tomography-based study.

PubMed

Pawanindra, Lal; Vindal, Anubhav; Midha, Manoj; Nagpal, Prashant; Manchanda, Alpana; Chander, Jagdish

2015-10-01

Pre- and post-operative stomach volumes can be important determinants for effectiveness of laparoscopic sleeve gastrectomy (LSG) in causing weight loss. There is little existing data on the volumes of stomach preoperatively and that excised during LSG. This study was designed to evaluate the change in gastric volume after LSG using multi-detector CT and to correlate it with early post-operative weight loss. Twenty consecutive patients with BMI ≥ 40 kg/m(2) and medical comorbidities underwent LSG between October 2011 and October 2013 and were analysed prospectively. The pre-operative stomach volume was measured by MDCT done 1-3 days before the surgery. LSG was performed in the standard manner using a 36F bougie. The volume of excised stomach was measured by distending the specimen with saline. MDCT of the upper abdomen was repeated 3 months postoperatively to calculate the gastric sleeve volume. Weight loss and resolution of comorbidities were documented. The mean pre-operative weight of patients was 123.90 kg, and the mean pre-operative stomach volume on MDCT was 1,067 ml. The stomach volume on pre-operative MDCT correlated with pre-operative weight and BMI. The mean volume of the excised stomach was 859 ml when measured by distension of the specimen and 850 ml on MDCT. After 3 months post surgery, the mean volume of gastric sleeve on MDCT was 217 ml, and the mean weight of the patients was 101.22 kg. The volume of the excised stomach calculated by MDCT correlated with the weight loss achieved 3 months postoperatively. However, no correlation was seen between the gastric sleeve volume 3 months postoperatively and weight loss during this period. MDCT is a good method to measure gastric volume before and after LSG. Early post-operative weight loss (3 months) correlates well with the volume of the excised stomach but not with that of the gastric sleeve.

All atypia diagnosed at stereotactic vacuum-assisted breast biopsy do not need surgical excision.

PubMed

de Mascarel, Isabelle; Brouste, Véronique; Asad-Syed, Maryam; Hurtevent, Gabrielle; Macgrogan, Gaëtan

2011-09-01

The necessity of excision is debatable when atypia are diagnosed at stereotactic vacuum-assisted breast biopsy (microbiopsy). Among the 287 surgical excisions performed at Institut Bergonié from 1999 to 2009, we selected a case-control study group of 151 excisions; 52 involving all the diagnosed cancers and 99 randomly selected among the 235 excisions without cancer, following atypical microbiopsy (24 flat epithelial atypia; 50 atypical ductal hyperplasia; 14 lobular neoplasia; 63 mixed lesions). Mammographical calcification (type, extension, complete removal) and histological criteria of epithelial atypia (type, number of foci, size/extension), topography and microcalcification extension at microbiopsy were compared according to the presence or absence of cancer at excision. Factors associated with cancer at excision were Breast Imaging Reporting and Data System (BI-RADS5) lesions, large and/or multiple foci of mammographical calcifications, histological type, number, size and extension of atypical foci. Flat epithelial atypia alone was never associated with cancer at excision. BI-RADS5, atypical ductal hyperplasia (alone or predominant) and >3 foci of atypia were identified as independent pejorative factors. There was never any cancer at excision when these pejorative factors were absent (n=31). Presence of one (n=59), two (n=23) or three (n=14) factors was associated with cancer in 24, 15 and 13 cases with an odds ratio=5.8 (95% CI: 3-11.2) for each additional factor. We recommend that mammographical data and histological characteristics be taken into account in the decision-making process after diagnosis of atypia on microbiopsy. With experienced senologists and strict histological criteria, some patients could be spared surgery resulting in significant patient, financial and time advantages.

Benign Intraductal Papilloma without Atypia on Core Needle Biopsy Has a Low Rate of Upgrading to Malignancy after Excision

PubMed Central

Han, Song-Hee; Kim, Milim; Chung, Yul Ri; Yun, Bo La; Jang, Mijung; Kim, Sun Mi; Kang, Eunyoung; Kim, Eun-Kyu

2018-01-01

Purpose The management of benign intraductal papilloma (IDP) without atypia diagnosed on core needle biopsy (CNB) remains controversial. This study was performed to evaluate the rate of upgrading to malignancy or high-risk lesions after excision and to identify factors associated with upgrading using a large series of benign IDP cases without atypia. Methods We included patients who were diagnosed as having benign IDP without atypia on CNB and underwent surgical or vacuum-assisted excision between 2010 and 2015. We analyzed the clinical, radiologic, and histopathologic features of IDPs that were upgraded to malignancy or high-risk lesions after excision. Results A total of 511 benign IDPs without atypia diagnosed via CNB were identified, of which 398 cases were treated with excision. After reviewing these cases, four cases of high-risk lesions in adjacent tissue on CNB, two cases which were revealed as papilloma with atypia, and nine cases of malignancy in the same breast were excluded. In the remaining 383 cases, the rate of upgrading to malignancy and high-risk lesions after excision was 0.8% and 4.4%, respectively. The presence of concurrent contralateral breast cancer, the presence of symptoms, and multifocality were factors significantly associated with upgrading to malignancy on subsequent excision. Surgical excision rather than vacuum-assisted excision was significantly associated with upgrading to high-risk lesions or malignancy. Conclusion The rate of upgrading to malignancy for benign IDP without atypia was very low, suggesting that close clinical and radiologic observation may be sufficient for patients with benign IDP without atypia on CNB under proper settings. PMID:29628987

Green and non-green callus induction from excised rice (Oryza sativa) embryos: effects of exogenous plant growth regulators

NASA Technical Reports Server (NTRS)

Kim, D.; Brock, T. G.; Kaufman, P. B.

1992-01-01

Calli were induced either from excised rice embryos or from whole seeds in the presence of 1 to 5 mg l-1 NAA. After 12 days of culture, calli were induced only from excised rice embryos. We found that excised embryos accumulated NAA up to 6 times higher concentration than did whole seeds. In the presence of 1 to 5 mg l-1 NAA and 2 to 10 mg l-1 kinetin, chlorophyllous calli were induced from excised rice embryos. Chlorophyll contents in the callus tissue increased with increasing kinetin concentration while percent callus induction decreased. The total chlorophyll content was linearly correlated with the ratio of kinetin to NAA in the medium.

Study on the excision and integration mediated by class 1 integron in Streptococcus pneumoniae.

PubMed

Lin, Qun; Xu, Pusheng; Li, Jiaowu; Huang, Jinhua; Chen, Yin; Deng, Shuhuan

2017-10-01

As a novel antibiotic resistance mobile element, integron was recognized as a primary source of antibiotic genes among Gram-positive organisms for its excision and integration of exogenous genes. In this study, Streptococcus pneumoniae was subjected to investigate the excision and integration of class 1 integron with eight different plasmids. As the results indicated, excision in both att site and gene cassettes were successfully observed, which was further confirmed by integration assays and PCR amplification. The observation of class 1 integron mediated excision and integration of various exogenous antibiotics resistance genes may raise the attention of integrons as novel antibiotic resistance determinant in Gram-positive bacteria, especially in Streptococcus. Copyright © 2017 Elsevier Ltd. All rights reserved.

Early excision and grafting versus delayed excision and grafting of deep thermal burns up to 40% total body surface area: a comparison of outcome

PubMed Central

Saaiq, M.; Zaib, S.; Ahmad, S.

2012-01-01

Summary This is a study of 120 patients of either sex and all ages who had sustained deep burns of up to 40% of the total body surface area. Half the patients underwent early excision and skin autografting (i.e., within 4-7 days of sustaining burn injury) while the rest underwent delayed excision and skin autografting (i.e., within 1-4 weeks post-burn). Significant differences were found in favour of the early excision and grafting group with regard to the various burn management outcome parameters taken into consideration, i.e. culture positivity of wounds, graft take, duration of post-graft hospitalization, and mortality. PMID:23467391

P element excision in drosophila melanogaster and related drosophilids

USDA-ARS?s Scientific Manuscript database

The frequency of P element excision and the structure of the resulting excision products were determined in three drosophilid species, Drosophila melanogaster, D. virilis, and Chymomyza procnemis. A transient P element mobility assay was conducted in the cells of developing insect embryos, but unlik...

Cigarette price minimization strategies in the United States: price reductions and responsiveness to excise taxes.

PubMed

Pesko, Michael F; Licht, Andrea S; Kruger, Judy M

2013-11-01

Because cigarette price minimization strategies can provide substantial price reductions for individuals continuing their usual smoking behaviors following federal and state cigarette excise tax increases, we examined independent price reductions compensating for overlapping strategies. The possible availability of larger independent price reduction opportunities in states with higher cigarette excise taxes is explored. Regression analysis used the 2006-2007 Tobacco Use Supplement of the Current Population Survey (N = 26,826) to explore national and state-level independent price reductions that smokers obtained from purchasing cigarettes (a) by the carton, (b) in a state with a lower average after-tax cigarette price than in the state of residence, and (c) in "some other way," including online or in another country. Price reductions from these strategies are estimated jointly to compensate for known overlapping strategies. Each strategy reduced the price of cigarettes by 64-94 cents per pack. These price reductions are 9%-22% lower than conventionally estimated results not compensating for overlapping strategies. Price reductions vary substantially by state. Following cigarette excise tax increases, the price reduction available from purchasing cigarettes by cartons increased. Additionally, the price reduction from purchasing cigarettes in a state with a lower average after-tax cigarette price is positively associated with state cigarette excise tax rates and border state cigarette excise tax rate differentials. Findings from this large, nationally representative study of cigarette smokers suggest that price reductions are larger in states with higher cigarette excise taxes, and increase as cigarette excise taxes rise.

Transposon based functional characterization of soybean genes

USDA-ARS?s Scientific Manuscript database

Type II transposable elements that use cut and paste mechanism for jumping from one genomic region to another is ideal in tagging and cloning genes. Precise excision from an insertion site in a mutant gene leads to regaining the wild-type function. Thus, function of a gene can be established based o...

26 CFR 48.0-1 - Introduction.

Code of Federal Regulations, 2010 CFR

2010-04-01

... MANUFACTURERS AND RETAILERS EXCISE TAXES Introduction § 48.0-1 Introduction. The regulations in this part 48 are designated “Manufacturers and Retailers Excise Tax Regulations.” The regulations relate to the excise taxes... automobiles, highway-type tires, taxable fuel, aviation fuel, coal, certain vaccines, and sporting goods...

Lymphoma diagnosis in histopathology using a multi-stage visual learning approach

NASA Astrophysics Data System (ADS)

Codella, Noel; Moradi, Mehdi; Matasar, Matt; Sveda-Mahmood, Tanveer; Smith, John R.

2016-03-01

This work evaluates the performance of a multi-stage image enhancement, segmentation, and classification approach for lymphoma recognition in hematoxylin and eosin (H and E) stained histopathology slides of excised human lymph node tissue. In the first stage, the original histology slide undergoes various image enhancement and segmentation operations, creating an additional 5 images for every slide. These new images emphasize unique aspects of the original slide, including dominant staining, staining segmentations, non-cellular groupings, and cellular groupings. For the resulting 6 total images, a collection of visual features are extracted from 3 different spatial configurations. Visual features include the first fully connected layer (4096 dimensions) of the Caffe convolutional neural network trained from ImageNet data. In total, over 200 resultant visual descriptors are extracted for each slide. Non-linear SVMs are trained over each of the over 200 descriptors, which are then input to a forward stepwise ensemble selection that optimizes a late fusion sum of logistically normalized model outputs using local hill climbing. The approach is evaluated on a public NIH dataset containing 374 images representing 3 lymphoma conditions: chronic lymphocytic leukemia (CLL), follicular lymphoma (FL), and mantle cell lymphoma (MCL). Results demonstrate a 38.4% reduction in residual error over the current state-of-art on this dataset.

26 CFR 53.4965-7 - Taxes on prohibited tax shelter transactions.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 26 Internal Revenue 17 2011-04-01 2011-04-01 false Taxes on prohibited tax shelter transactions... (CONTINUED) MISCELLANEOUS EXCISE TAXES (CONTINUED) FOUNDATION AND SIMILAR EXCISE TAXES Second Tier Excise Taxes § 53.4965-7 Taxes on prohibited tax shelter transactions. (a) Entity-level taxes—(1) In general...

27 CFR 70.412 - Excise taxes.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 27 Alcohol, Tobacco Products and Firearms 2 2011-04-01 2011-04-01 false Excise taxes. 70.412 Section 70.412 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT... Beer § 70.412 Excise taxes. (a) Collection. Taxes on distilled spirits, wines, and beer are paid by...

Alternative Fuels Data Center

Science.gov Websites

Idle Reduction Equipment Excise Tax Exemption Qualified on-board idle reduction devices and advanced insulation are exempt from the federal excise tax imposed on the retail sale of heavy-duty highway ) SmartWay Technology Program Federal Excise Tax Exemption website. The exemption applies to equipment that

A Study to Determine the Best Method of Caring for Certain Short-Stay Surgical Patients at Reynolds Army Community Hospital

DTIC Science & Technology

1988-09-01

Perineoplasty Vaginal cyst, cautery Vaginal web, excision Surgical Patients 95 ORTHOPEDIC Arthrodesis of phalanges Arthroscopy Bone biopsy Bunionectomy...Manipulation of shoulder, knee, or hip Mass excision with scar revision Meniscectomy (if done through arthroscopy ) Metatarsal head, excision unilateral

76 FR 46677 - Indoor Tanning Services; Cosmetic Services Excise Taxes

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-03

... 1545-BJ40 Indoor Tanning Services; Cosmetic Services Excise Taxes AGENCY: Internal Revenue Service (IRS... of public hearing on proposed rulemaking providing guidance on the indoor tanning services excise tax... indoor tanning services. DATES: The public hearing is being held on Tuesday, October 11, 2011, at 10 a.m...

Excision of an enlarging vaginal epidermal inclusion cyst during pregnancy: a case report.

PubMed

Pereira, Nigel; Guilfoil, Daniel S

2012-07-01

The study aimed to report the case of a patient with an enlarging and symptomatic epidermal inclusion cyst during pregnancy that required surgical excision. This study was a case report of a 28-year-old woman (gravida 8, para 5, aborta 2) at a gestational age of 18 weeks 5 days who reported a tender vaginal mass that had grown larger for more than a week. An enlarging symptomatic cystic mass was surgically excised. Histopathologic findings of the excised mass were consistent with an epidermal inclusion cyst with surrounding moderate chronic inflammation and cyst rupture. The patient's symptoms resolved completely by her postoperative visit. Although most epithelial inclusion cysts are asymptomatic and can be managed expectantly, cysts that enlarge or become symptomatic should be excised surgically.

[Anesthetic management of the ex-utero intrapartum treatment (EXIT) procedure for giant epignathus and of the tumor excision].

PubMed

Aoyama, Tadashi; Nakata, Jun; Sakakibara, Michiko; Takahashi, Tetsuyuki; Hara, Masato; Yamaguchi, Shinya; Maseki, Megumi; Teramoto, Yuzo

2008-10-01

We report an anesthetic management of the ex-utero intrapartum treatment (EXIT) procedure performed in a fetus with giant epignathus due to laryngeal atresia at 28 weeks' gestation. Anesthesia of the mother was induced with thiamylal and vecuronium, and maintained with 4% sevoflurane in 100% oxygen before delivery. Sevoflurane provided excellent uterine relaxation. To maintain the arterial pressure, the patient received acetate Ringer and ephedrine 4mg. After hysterotomy, a pulse oxymeter and an ultrasound transducer were applied to monitor fetal Sp(O2) and heart rate. No anesthetic agents were injected into the fetus in addition to transplacental sevoflurane. Tracheostomy was performed on the fetus by pediatric surgeons on placental support. The uterine tone improved soon after discontinuing sevoflurane, intramyometrial injection of oxytocin and ergometrine infusion after delivery. Excision of the tumor was performed on day 2 of life. Pediatric surgeons tried to excise it totally, but it was hard to differentiate the tumor from the normal tissue, and partial excision was performed. After the excision, the neonate weighed 944 g and excised specimen weighed 253 g. Though the neonate was immature and the tumor was very large, no perioperative complications were associated with EXIT and the tumor excision.

In-Office Excision En Masse of a Vocal Process Granuloma Using the Potassium-Titanyl-Phosphate Laser.

PubMed

Mascarella, Marco A; Young, Jonathan

2016-01-01

In-office laryngeal surgery is taking on a more commonplace role in the treatment of laryngeal disorders. The potassium-titanyl-phosphate (KTP) laser has been a resourceful adjunct to the management of patients with mucosal lesions of the vocal cords. However, a paucity of data exists for its use in postintubation granulomas treated in-office. A 43-year-old female presented with voice hoarseness and found to have a large obstructing postintubation granuloma which was treated by in-office KTP laser and en masse excision. We report the successful case of a patient receiving in-office treatment for a large vocal process granuloma using the KTP laser with en masse excision. The combined use of the KTP laser and forceps in-office can be valuable to the surgical management of vocal process granulomas, given their numerous recurrences. New avenues in office-based surgical management of laryngeal disorders can offer accessibility and decreased morbidity to patients. Copyright © 2016 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Overexpression of dominant negative PARP interferes with tumor formation of HeLa cells in nude mice: evidence for increased tumor cell apoptosis in vivo.

PubMed

Hans, M A; Müller, M; Meyer-Ficca, M; Bürkle, A; Küpper, J H

1999-11-25

Poly(ADP-ribose) polymerase (PARP4) catalyzes the formation of ADP-ribose polymers covalently attached to proteins by using NAD+ as substrate. PARP is strongly activated by DNA single- or double-strand breaks and is thought to be involved in cellular responses to DNA damage. We characterized a dominant negative PARP mutant, i.e. the DNA-binding domain of this enzyme, whose overexpression in cells leads to increased genetic instability following DNA damage. In order to study whether PARP activity is also implicated in the process of tumorigenesis, we generated stably transfected HeLa cell clones with constitutive overexpression of dominant negative PARP and investigated tumor formation of these clones in nude mice. We found that inhibition of PARP activity dramatically reduces tumor forming ability of HeLa cells. Moreover, we provide strong evidence that the observed reduction in tumor forming ability is due to increased tumor cell apoptosis in vivo. Viewed together, our data and those from other groups show that inhibition of PARP enzyme activity interferes with DNA base excision repair and leads to increased genetic instability and recombination but, on the other hand, can sensitize cells to apoptotic stimuli and by this mechanism may prevent tumor formation.

Evidence for a Role of FEN1 in Maintaining Mitochondrial DNA Integrity

PubMed Central

Kalifa, Lidza; Beutner, Gisela; Phadnis, Naina; Sheu, Shey-Shing; Sia, Elaine A.

2009-01-01

Although the nuclear processes responsible for genomic DNA replication and repair are well characterized, the pathways involved in mitochondrial DNA (mtDNA) replication and repair remain unclear. DNA repair has been identified as being particularly important within the mitochondrial compartment due to the organelle’s high propensity to accumulate oxidative DNA damage. It has been postulated that continual accumulation of mtDNA damage and subsequent mutagenesis may function in cellular aging. Mitochondrial base excision repair (mtBER) plays a major role in combating mtDNA oxidative damage; however, the proteins involved in mtBER have yet to be fully characterized. It has been established that during nuclear long-patch (LP) BER, FEN1 is responsible for cleavage of 5′ flap structures generated during DNA synthesis. Furthermore, removal of 5′ flaps has been observed in mitochondrial extracts of mammalian cell lines; yet, the mitochondrial localization of FEN1 has not been clearly demonstrated. In this study, we analyzed the effects of deleting the yeast FEN1 homolog, RAD27, on mtDNA stability in Saccharomyces cerevisiae. Our findings demonstrate that Rad27p/FEN1 is localized in the mitochondrial compartment of both yeast and mice and that Rad27p has a significant role in maintaining mtDNA integrity. PMID:19699691

Evaluation of experimental transection and partial excision of the caudal cruciate ligament in dogs.

PubMed

Harari, J; Johnson, A L; Stein, L E; Kneller, S K; Pijanowski, G

1987-01-01

The caudal cruciate ligament (CaCL) of one stifle joint in seven dogs was transected and a 2 to 4 mm section was removed. Six months after surgery, none of the dogs were lame. Thigh muscle circumference, stifle range of motion, and internal tibial rotation in the operated limb were not significantly different from the preoperative measurements or the contralateral, unoperated limb. A caudal drawer motion was consistently present in the stifle joints with a transected CaCL. A radiographic evaluation of the operated stifle joints did not reveal osteoarthritic changes; four of seven stifle joints had an irregular fat pad 6 months after surgery. Results of a joint fluid analysis revealed a slight increase in synovial cells within treated stifle joints; inflammatory cells were not observed. The only gross morphologic change in stifle joints with a severed ligament was enlarged knobby remnants of the CaCL. Articular cartilage defects or osteophytes were not observed. Results of a histologic examination of the CaCL remnants revealed synovial cellular capping and intraligamentous fibroplasia. Based on a limited number of dogs, it was concluded that isolated transection of the CaCL produced minimal clinical and pathologic changes in the stifle joint during a 6 month period.

Comparison of Cornea Module and DermaInspect for noninvasive imaging of ocular surface pathologies

NASA Astrophysics Data System (ADS)

Steven, Philipp; Müller, Maya; Koop, Norbert; Rose, Christian; Hüttmann, Gereon

2009-11-01

Minimally invasive imaging of ocular surface pathologies aims at securing clinical diagnosis without actual tissue probing. For this matter, confocal microscopy (Cornea Module) is in daily use in ophthalmic practice. Multiphoton microscopy is a new optical technique that enables high-resolution imaging and functional analysis of living tissues based on tissue autofluorescence. This study was set up to compare the potential of a multiphoton microscope (DermaInspect) to the Cornea Module. Ocular surface pathologies such as pterygia, papillomae, and nevi were investigated in vivo using the Cornea Module and imaged immediately after excision by DermaInspect. Two excitation wavelengths, fluorescence lifetime imaging and second-harmonic generation (SHG), were used to discriminate different tissue structures. Images were compared with the histopathological assessment of the samples. At wavelengths of 730 nm, multiphoton microscopy exclusively revealed cellular structures. Collagen fibrils were specifically demonstrated by second-harmonic generation. Measurements of fluorescent lifetimes enabled the highly specific detection of goblet cells, erythrocytes, and nevus-cell clusters. At the settings used, DermaInspect reaches higher resolutions than the Cornea Module and obtains additional structural information. The parallel detection of multiphoton excited autofluorescence and confocal imaging could expand the possibilities of minimally invasive investigation of the ocular surface toward functional analysis at higher resolutions.

Alternative splicing at exon 2 results in the loss of the catalytic activity of mouse DNA polymerase iota in vitro.

PubMed

Kazachenko, Konstantin Y; Miropolskaya, Nataliya A; Gening, Leonid V; Tarantul, Vyacheslav Z; Makarova, Alena V

2017-02-01

Y-family DNA polymerase iota (Pol ι) possesses both DNA polymerase and dRP lyase activities and was suggested to be involved in DNA translesion synthesis and base excision repair in mammals. The 129 strain of mice and its derivatives have a natural nonsense codon mutation in the second exon of the Pol ι gene resulting in truncation of the Pol ι protein. These mice were widely used as a Pol ι-null model for in vivo studies of the Pol ι function. However whether 129-derived strains of mice are fully deficient in the Pol ι functions was a subject of discussion since Pol ι mRNA undergoes alternative splicing at exon 2. Here we report purification of mouse Pol ι lacking the region encoded by exon 2, which includes several conserved residues involved in catalysis. We show that the deletion abrogates both the DNA polymerase and dRP lyase activities of Pol ι in the presence of either Mg 2+ or Mn 2+ ions. Thus, 129-derived strains of mice express catalytically inactive alternatively spliced Pol ι variant, whose cellular functions, if any exist, remain to be established. Copyright © 2017 Elsevier B.V. All rights reserved.

Detection of Damaged DNA Bases by DNA Glycosylase Enzymes†

PubMed Central

Friedman, Joshua I.; Stivers, James T.

2010-01-01

A fundamental and shared process in all forms of life is the use of DNA glycosylase enzymes to excise rare damaged bases from genomic DNA. Without such enzymes, the highly-ordered primary sequences of genes would rapidly deteriorate. Recent structural and biophysical studies are beginning to reveal a fascinating multistep mechanism for damaged base detection that begins with short-range sliding of the glycosylase along the DNA chain in a distinct conformation we refer to as the search complex (SC). Sliding is frequently punctuated by the formation of a transient “interrogation” complex (IC) where the enzyme extrahelically inspects both normal and damaged bases in an exosite pocket that is distant from the active site. When normal bases are presented in the exosite, the IC rapidly collapses back to the SC, while a damaged base will efficiently partition forward into the active site to form the catalytically competent excision complex (EC). Here we review the unique problems associated with enzymatic detection of rare damaged DNA bases in the genome, and emphasize how each complex must have specific dynamic properties that are tuned to optimize the rate and efficiency of damage site location. PMID:20469926

Developing an in silico model of the modulation of base excision repair using methoxyamine for more targeted cancer therapeutics.

PubMed

Gurkan-Cavusoglu, Evren; Avadhani, Sriya; Liu, Lili; Kinsella, Timothy J; Loparo, Kenneth A

2013-04-01

Base excision repair (BER) is a major DNA repair pathway involved in the processing of exogenous non-bulky base damages from certain classes of cancer chemotherapy drugs as well as ionising radiation (IR). Methoxyamine (MX) is a small molecule chemical inhibitor of BER that is shown to enhance chemotherapy and/or IR cytotoxicity in human cancers. In this study, the authors have analysed the inhibitory effect of MX on the BER pathway kinetics using a computational model of the repair pathway. The inhibitory effect of MX depends on the BER efficiency. The authors have generated variable efficiency groups using different sets of protein concentrations generated by Latin hypercube sampling, and they have clustered simulation results into high, medium and low efficiency repair groups. From analysis of the inhibitory effect of MX on each of the three groups, it is found that the inhibition is most effective for high efficiency BER, and least effective for low efficiency repair.

Microbiological sampling of swine carcasses: a comparison of data obtained by swabbing with medical gauze and data collected routinely by excision at Swedish abattoirs.

PubMed

Lindblad, M

2007-09-15

Swab sample data from a 13-month microbiological baseline study of swine carcasses at Swedish abattoirs were combined with excision sample data collected routinely at five abattoirs. The aim was to compare the numbers of total aerobic counts, Enterobacteriaceae, and Escherichia coli, recovered by swabbing four carcass sites with gauze (total area 400 cm2) with those obtained by excision at equivalent sites (total area 20 cm2). The results are considered in relation to the process hygiene criteria that are stated in Commission Regulation (EC) No 2073/2005. These criteria apply only to destructive sampling of total aerobic counts and Enterobacteriaceae, but alternative sampling schemes, as well as alternative indicator organisms such as E. coli, are allowed if equivalent guarantees of food safety can be provided. Swab sampling resulted in higher mean log numbers of total aerobic counts at four of the five abattoirs, compared with excision, and lower or equal standard deviations at all abattoirs. The percentage of swab and excision samples positive for Enterobacteriaceae at the different abattoirs ranged from 68 to 100% and 15 to 24%, respectively. Similarly, the percentages of swab samples that were positive for E. coli were higher than the percentages of positive excision samples (range 52 to 84% and 3 to 14%, respectively). Due to the low percentage of positive excision results, the mean log numbers of Enterobacteriaceae and E. coli were only compared at two and one abattoirs, respectively, using log probability regression to substitute censored observations. Higher mean log numbers of Enterobacteriaceae were recovered by swabbing compared with excision at one abattoir, whereas the numbers of Enterobacteriaceae and E. coli did not differ significantly between sampling methods at one abattoir. This study suggests that the same process hygiene criteria as those stipulated for excision can be used for swabbing with gauze without compromising food safety. For monitoring of low numbers of Enterobacteriaceae and E. coli, like those found on swine carcasses at Swedish abattoirs, the results also show that swabbing of a relatively large area is superior to excision of a smaller area.

Pathogenicity Island Cross Talk Mediated by Recombination Directionality Factors Facilitates Excision from the Chromosome.

PubMed

Carpenter, Megan R; Rozovsky, Sharon; Boyd, E Fidelma

2015-12-14

Pathogenicity islands (PAIs) are mobile integrated genetic elements (MIGEs) that contain a diverse range of virulence factors and are essential in the evolution of pathogenic bacteria. PAIs are widespread among bacteria and integrate into the host genome, commonly at a tRNA locus, via integrase-mediated site-specific recombination. The excision of PAIs is the first step in the horizontal transfer of these elements and is not well understood. In this study, we examined the role of recombination directionality factors (RDFs) and their relationship with integrases in the excision of two PAIs essential for Vibrio cholerae host colonization: Vibrio pathogenicity island 1 (VPI-1) and VPI-2. VPI-1 does not contain an RDF, which allowed us to answer the question of whether RDFs are an absolute requirement for excision. We found that an RDF was required for efficient excision of VPI-2 but not VPI-1 and that RDFs can induce excision of both islands. Expression data revealed that the RDFs act as transcriptional repressors to both VPI-1- and VPI-2-encoded integrases. We demonstrated that the RDFs Vibrio excision factor A (VefA) and VefB bind at the attachment sites (overlapping the int promoter region) of VPI-1 and VPI-2, thus supporting this mode of integrase repression. In addition, V. cholerae RDFs are promiscuous due to their dual functions of promoting excision of both VPI-1 and VPI-2 and acting as negative transcriptional regulators of the integrases. This is the first demonstration of cross talk between PAIs mediated via RDFs which reveals the complex interactions that occur between separately acquired MIGEs. Deciphering the mechanisms of pathogenicity island excision is necessary for understanding the evolution and spread of these elements to their nonpathogenic counterparts. Such mechanistic insight would assist in predicting the mobility of uncharacterized genetic elements. This study identified extensive RDF-mediated cross talk between two nonhomologous VPIs and demonstrated the dual functionality of RDF proteins: (i) inducing PAI excision and (ii) acting as transcriptional regulators. Findings from this study may be implicated in determining the mobilome contribution of other bacteria with multiple MIGEs. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

A case of hemangiopericytoma of the soft palate with articulate disorder and dysphagia

PubMed Central

Michi, Yasuyuki; Suzuki, Miho; Kurohara, Kazuto; Harada, Kiyoshi

2013-01-01

We report a case of hemangiopericytoma of the soft palate of 60-year-old patient, who noticed a mass of the soft palate and experienced difficulty in speaking. We found a pediculate, hard, elastic mass measuring 38 mm (cross-sectional diameter). Computed tomography (CT) scans and dynamic magnetic resonance imaging (MRI) confirmed irregularly shaped mass and revealed a heterogeneous internal composition, consistent with vascular tumors. We excised the tumor under general anesthesia. Histopathological diagnosis was based on positive immunoreactivity of CD99 and vimentin and weak, positive staining of CD34. Three and half years following tumor excision, there is no recurrence or metastasis. PMID:23703709

Radial scars diagnosed on breast core biopsy: Frequency of atypia and carcinoma on excision and implications for management.

PubMed

Donaldson, Alana R; Sieck, Leah; Booth, Christine N; Calhoun, Benjamin C

2016-12-01

The risk of finding carcinoma in excisions following a core needle biopsy diagnosis of radial scar is not well defined and clinical management is variable. The aim of this study is to determine the frequency of high-risk lesions, ductal carcinoma in situ, and invasive carcinoma in excisions following a core biopsy diagnosis of radial scar. Dedicated breast pathologists and radiologists correlated the histologic and radiologic findings and categorized radial scars as the target lesion or an incidental finding. High-risk lesions were defined as atypical hyperplasia or classical lobular carcinoma in situ. Of the 79 radial scars identified over a 14-year period, 22 were associated with atypia or carcinoma in the core biopsy. Thirty-seven (37) of the 57 benign radial scars underwent excision with benign findings in 30 (81%), high-risk lesions in six (16%), and flat epithelial atypia in one (3%). There were no upgrades to carcinoma. One patient with a benign radial scar developed a 3-mm focus of intermediate-grade estrogen receptor-positive ductal carcinoma in situ in the same quadrant of the ipsilateral breast 72 months after excision. One patient with an incidental un-excised benign radial scar was diagnosed with ductal carcinoma in situ at a separate site of suspicious calcifications. In this series, none of the benign radial scars was upgraded to carcinoma. Radial scar was the targeted lesion in all cases with high-risk lesions on excision. Surgical excision may not be mandatory for patients with benign incidental radial scars on core biopsy. Copyright © 2016 Elsevier Ltd. All rights reserved.

Histologic effects of a high-repetition pulsed Nd:YAG laser on intraoral soft tissue

NASA Astrophysics Data System (ADS)

White, Joel M.; Goodis, Harold E.; Yessik, Michael J.; Myers, Terry D.

1995-05-01

High-repetition rate, fiberoptic-delivered Nd:YAG lasers have increased oral soft tissue laser applications. This study focused on three parameters: the temperature rise occurring in deeper tissue during excision, the histology of thermal coagulation during excision of oral tissue, and effects of accidental exposure to adjacent hard tissue. Thermocouples were placed 5.0 +/- 0.5 mm in bone below fresh bovine gingiva and at the same depth in tongue; temperatures in the underlying tissue were measured during laser excision. An Nd:YAG laser with 100 microsecond(s) pulse duration was used to excise the tissue using a 200 or 300 micrometers diameter fiber in contact with the tissue. The soft tissue was excised using constant force and rate with laser powers of 1.5, 3, 5, and 10 W, and a variety of pulse rates. The tissue was bioprepared, sectioned and stained with hematoxylin and eosin. The width and depth of the tissue removed as well as lateral and deep thermal coagulation were measured in histologic sections with a measuring microscope (10x). Multifactor randomized ANOVA showed that probe diameter and repetition rates were not significant variables (p

Factors associated with the number of lesions excised for each skin cancer: a study of primary care physicians in Queensland, Australia.

PubMed

Baade, Peter D; Youl, Philippa H; Janda, Monika; Whiteman, David C; Del Mar, Christopher B; Aitken, Joanne F

2008-11-01

To assess physician, patient, and skin lesion characteristics that affect the number of benign skin lesions excised by primary care physicians for each skin cancer. Prospective study collecting clinical, patient, and histopathologic details of excisions or biopsies of skin lesions by random samples of primary care physicians. Southeast Queensland involving traditional family medicine physicians (n = 104; response rate, 53.9%) and family medicine physicians working in 27 primary care skin cancer clinics (n = 50; response rate, 75.0%). Of 28 755 skin examinations recorded during the study, 11 403 skin lesions were excised or biopsied; 97.5% of the excised lesions had clinical and histologic diagnoses recorded. Number of lesions needed to excise or biopsy (NNE) for 1 melanoma (pigmented lesions only) and NNE for 1 nonmelanoma skin cancer (nonpigmented lesions only). The NNE for nonpigmented lesions (n = 8139) was 1.5 (95% confidence interval, 1.4-1.6) and for pigmented lesions (n = 2977) was 19.6 (16.2-22.9). The NNE estimates were up to 8 times lower if the physician thought the lesion was likely to be malignant and up to 2.5 times higher if there was strong patient pressure to excise. The NNE estimates varied by other physician-, patient-, and lesion-related variables. Clinical impressions of excised skin lesions were strongly associated with NNE estimates. By focusing on pigmented skin lesions and by addressing the physician- and patient-specific factors identified, the effectiveness of future training for primary care physicians in the clinical management of skin cancer could be improved.

Cigarette Price Minimization Strategies in the United States: Price Reductions and Responsiveness to Excise Taxes

PubMed Central

2013-01-01

Introduction: Because cigarette price minimization strategies can provide substantial price reductions for individuals continuing their usual smoking behaviors following federal and state cigarette excise tax increases, we examined independent price reductions compensating for overlapping strategies. The possible availability of larger independent price reduction opportunities in states with higher cigarette excise taxes is explored. Methods: Regression analysis used the 2006–2007 Tobacco Use Supplement of the Current Population Survey (N = 26,826) to explore national and state-level independent price reductions that smokers obtained from purchasing cigarettes (a) by the carton, (b) in a state with a lower average after-tax cigarette price than in the state of residence, and (c) in “some other way,” including online or in another country. Price reductions from these strategies are estimated jointly to compensate for known overlapping strategies. Results: Each strategy reduced the price of cigarettes by 64–94 cents per pack. These price reductions are 9%–22% lower than conventionally estimated results not compensating for overlapping strategies. Price reductions vary substantially by state. Following cigarette excise tax increases, the price reduction available from purchasing cigarettes by cartons increased. Additionally, the price reduction from purchasing cigarettes in a state with a lower average after-tax cigarette price is positively associated with state cigarette excise tax rates and border state cigarette excise tax rate differentials. Conclusions: Findings from this large, nationally representative study of cigarette smokers suggest that price reductions are larger in states with higher cigarette excise taxes, and increase as cigarette excise taxes rise. PMID:23729501

Optimization of the Ussing chamber setup with excised rat intestinal segments for dissolution/permeation experiments of poorly soluble drugs.

PubMed

Forner, Kristin; Roos, Carl; Dahlgren, David; Kesisoglou, Filippos; Konerding, Moritz A; Mazur, Johanna; Lennernäs, Hans; Langguth, Peter

2017-02-01

Prediction of the in vivo absorption of poorly soluble drugs may require simultaneous dissolution/permeation experiments. In vivo predictive media have been modified for permeation experiments with Caco-2 cells, but not for excised rat intestinal segments. The present study aimed at improving the setup of dissolution/permeation experiments with excised rat intestinal segments by assessing suitable donor and receiver media. The regional compatibility of rat intestine in Ussing chambers with modified Fasted and Fed State Simulated Intestinal Fluids (Fa/FeSSIF mod ) as donor media was evaluated via several parameters that reflect the viability of the excised intestinal segments. Receiver media that establish sink conditions were investigated for their foaming potential and toxicity. Dissolution/permeation experiments with the optimized conditions were then tested for two particle sizes of the BCS class II drug aprepitant. Fa/FeSSIF mod were toxic for excised rat ileal sheets but not duodenal sheets, the compatibility with jejunal segments depended on the bile salt concentration. A non-foaming receiver medium containing bovine serum albumin (BSA) and Antifoam B was nontoxic. With these conditions, the permeation of nanosized aprepitant was higher than of the unmilled drug formulations. The compatibility of Fa/FeSSIF mod depends on the excised intestinal region. The chosen conditions enable dissolution/permeation experiments with excised rat duodenal segments. The experiments correctly predicted the superior permeation of nanosized over unmilled aprepitant that is observed in vivo. The optimized setup uses FaSSIF mod as donor medium, excised rat duodenal sheets as permeation membrane and a receiver medium containing BSA and Antifoam B.

Identification of a residue critical for the excision of 3′-blocking ends in apurinic/apyrimidinic endonucleases of the Xth family

PubMed Central

Castillo-Acosta, Víctor M.; Ruiz-Pérez, Luis M.; Yang, Wei; González-Pacanowska, Dolores; Vidal, Antonio E.

2009-01-01

DNA single-strand breaks containing 3′-blocking groups are generated from attack of the sugar backbone by reactive oxygen species or after base excision by DNA glycosylase/apurinic/apyrimidinic (AP) lyases. In human cells, APE1 excises sugar fragments that block the 3′-ends thus facilitating DNA repair synthesis. In Leishmania major, the causal agent of leishmaniasis, the APE1 homolog is the class II AP endonuclease LMAP. Expression of LMAP but not of APE1 reverts the hypersensitivity of a xth nfo repair-deficient Escherichia coli strain to the oxidative compound hydrogen peroxide (H2O2). To identify the residues specifically involved in the repair of oxidative DNA damage, we generated random mutations in the ape1 gene and selected those variants that conferred protection against H2O2. Among the resistant clones, we isolated a mutant in the nuclease domain of APE1 (D70A) with an increased capacity to remove 3′-blocking ends in vitro. D70 of APE1 aligns with A138 of LMAP and mutation of the latter to aspartate significantly reduces its 3′-phosphodiesterase activity. Kinetic analysis shows a novel role of residue D70 in the excision rate of 3′-blocking ends. The functional and structural differences between the parasite and human enzymes probably reflect a divergent molecular evolution of their DNA repair responses to oxidative damage. PMID:19181704

Temporal fossa hemangiopericytoma: a case series.

PubMed

Heiser, Marc A; Waldron, James S; Tihan, Tarik; Parsa, Andrew T; Cheung, Steven W

2009-10-01

Review clinical experience with temporal fossa hemangiopericytomas (HPCs). Retrospective case series review. Tertiary referral center. Intracranial HPCs within the temporal fossa. Craniotomy for either subtotal or gross total tumor excision. Determination of clinical outcome (alive with no evidence of disease, alive with disease, and died of disease). Five cases of HPC involving the temporal fossa were treated at our tertiary referral center for the period from 1995 to 2008. All but 1 patient were men. The age of presentation ranged from 31 to 62 years, and duration of follow-up ranged from 8 to 153 months. Clinical presentation was protean; headache was the most common symptom. Gross total tumor excision was achieved in 2 patients, whereas subtotal tumor excision was achieved in 3 patients. Reasons for subtotal resection included excessive intraoperative blood loss and inextricable tumor. Histologically, all tumors were composed of tightly packed, randomly oriented (jumbled-up) tumor cells with little intervening collagen. CD34 staining mostly highlighted the vascular background. One patient died of disease, 2 patients were alive with disease, and 2 patients had no evidence of disease. Management of temporal fossa HPC is challenging because clinical presentation is often late, and extent of tumor excision is constrained by vital structures in the cranial base and intracranial contents. A multidisciplinary approach with neurosurgery and neurotology undertaken to achieve the most complete tumor resection possible, whereas minimizing morbidity are likely to confer a longer period of symptom-free survival and improves curability of these difficult lesions.

Genetic Effects of Uv Irradiation on Excision-Proficient and -Deficient Yeast during Meiosis

PubMed Central

Resnick, Michael A.; Game, John C.; Stasiewicz, Stanley

1983-01-01

The lethal and recombinational responses to ultraviolet light irradiation (UV) by excision-proficient (RAD+) and deficient strains (rad1) of Saccharomyces cerevisiae has been examined in cells undergoing meiosis. Cells that exhibit high levels of meiotic synchrony were irradiated either at the beginning or at various times during meiosis and allowed to proceed through meiosis. Based on survival responses, the only excision repair mechanism for UV damage available during meiosis is that controlled by the RAD1 pathway. The presence of pyrimidine dimers at the beginning of meiosis does not prevent cells from undergoing meiosis; however, the spore products exhibit much lower survival than cells from earlier stages of meiosis. The reduced survival is probably due to effects of UV on recombination. Meiotic levels of gene conversion are reduced only two to three times in these experiments; however, intergenic recombination is nearly abolished after a dose of 4 J/m 2 to the rad1 strain. Exposure to 25 J/m2 had little effect on the wild-type strain. Since normal meiotic reciprocal recombination is generally considered to involve gene conversion-type intermediates, it appears that unrepaired UV damage dissociates the two processes. These results complement those obtained with the mei-9 mutants of Drosophila which also demonstrate a dissociation between gene conversion and reciprocal recombination. These results are consistent with molecular observations on the UV-irradiated rad1 strain in that there is no excision of pyrimidine dimers or exchange of dimers during meiosis. PMID:6352405

Strand displacement synthesis by yeast DNA polymerase ε.

PubMed

Ganai, Rais A; Zhang, Xiao-Ping; Heyer, Wolf-Dietrich; Johansson, Erik

2016-09-30

DNA polymerase ε (Pol ε) is a replicative DNA polymerase with an associated 3'-5' exonuclease activity. Here, we explored the capacity of Pol ε to perform strand displacement synthesis, a process that influences many DNA transactions in vivo We found that Pol ε is unable to carry out extended strand displacement synthesis unless its 3'-5' exonuclease activity is removed. However, the wild-type Pol ε holoenzyme efficiently displaced one nucleotide when encountering double-stranded DNA after filling a gap or nicked DNA. A flap, mimicking a D-loop or a hairpin structure, on the 5' end of the blocking primer inhibited Pol ε from synthesizing DNA up to the fork junction. This inhibition was observed for Pol ε but not with Pol δ, RB69 gp43 or Pol η. Neither was Pol ε able to extend a D-loop in reconstitution experiments. Finally, we show that the observed strand displacement synthesis by exonuclease-deficient Pol ε is distributive. Our results suggest that Pol ε is unable to extend the invading strand in D-loops during homologous recombination or to add more than two nucleotides during long-patch base excision repair. Our results support the hypothesis that Pol ε participates in short-patch base excision repair and ribonucleotide excision repair. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

The Influence of Hepatitis C Virus Therapy on the DNA Base Excision Repair System of Peripheral Blood Mononuclear Cells.

PubMed

Czarny, Piotr; Merecz-Sadowska, Anna; Majchrzak, Kinga; Jabłkowski, Maciej; Szemraj, Janusz; Śliwiński, Tomasz; Karwowski, Bolesław

2017-07-01

Hepatitis C virus (HCV) can infect extrahepatic tissues, including lymphocytes, creating reservoir of the virus. Moreover, HCV proteins can interact with DNA damage response proteins of infected cells. In this article we investigated the influence of the virus infection and a new ombitasvir/paritaprevir/ritonavir ± dasabuvir ± ribavirin (OBV/PTV/r ± DSV ± RBV) anti-HCV therapy on the PBMCs (peripheral blood mononuclear cells, mainly lymphocytes) DNA base excision repair (BER) system. BER protein activity was analyzed in the nuclear and mitochondrial extracts (NE and ME) of PBMC isolated from patients before and after therapy, and from subjects without HCV, using modeled double-strand DNA, with 2'-deoxyuridine substitution as the DNA damage. The NE and ME obtained from patients before therapy demonstrated lower efficacy of 2'-deoxyuridine removal and DNA repair polymerization than those of the control group or patients after therapy. Moreover, the extracts from the patients after therapy had similar activity to those from the control group. However, the efficacy of apurinic/apyrimidinic site excision in NE did not differ between the studied groups. We postulate that infection of lymphocytes by the HCV can lead to a decrease in the activity of BER enzymes. However, the use of novel therapy results in the improvement of glycosylase activity as well as the regeneration of endonuclease and other crucial repair enzymes.

Biopsy and selective recall compared with immediate large loop excision in management of women with low grade abnormal cervical cytology referred for colposcopy: multicentre randomised controlled trial.

PubMed

2009-07-28

To compare the effectiveness of punch biopsy and selective recall for treatment versus a policy of immediate treatment by large loop excision in the management of women with low grade abnormal cervical cytology referred for colposcopy. Multicentre individually randomised controlled trial, nested within the NHS cervical screening programmes. Grampian, Tayside, and Nottingham. 1983 women, aged 20-59, with cytology showing borderline nuclear abnormalities or mild dyskaryosis, October 1999-October 2002. Immediate large loop excision or up to four targeted punch biopsies taken immediately with recall for treatment (by large loop excision) if these showed cervical intraepithelial neoplasia grade II or III or worse. Participants were followed for three years, concluding with an exit colposcopy. Clinical end points: cumulative incidence of cervical intraepithelial neoplasia grade II or worse and grade III or worse at three years. Clinically significant anxiety and depression and self reported after effects assessed six weeks after colposcopy, biopsies, or large loop excision. 879 women (44%) had a normal transformation zone at colposcopy and had no further procedures at that time. Colposcopists were less likely to classify the transformation zone as abnormal when the allocation was large loop excision (603 (60%) in the biopsy and selective recall group; 501 (51%) in the immediate large loop excision group). Of women randomised to biopsy and recall, 157 (16%) required a second clinic visit for treatment. Specimens from almost 60% (n=296) of women who underwent immediate large loop excision showed no cervical intraepithelial neoplasia (31%; n=156) or showed cervical intraepithelial neoplasia grade I (28%; n=140). The percentages of women diagnosed with grade II or worse up to and including the exit examination were 22% (n=216) in the biopsy and recall arm and 23% (n=228) in the immediate large loop excision arm. There was no significant difference between the arms in cumulative incidence of cervical intraepithelial neoplasia grade II or worse (adjusted relative for risk large loop excision v biopsy 1.04, 95% confidence interval 0.86 to 1.25) or grade III or worse (1.03, 0.79 to 1.34). A greater proportion of disease was detected at initial investigation and less during follow-up and at exit in the immediate large loop excision arm, but time of detection did not differ significantly between arms. Levels of anxiety and depression and reported pain did not differ between arms. Higher proportions of women randomised to large loop excision reported moderate or more severe bleeding and discharge. A policy of targeted punch biopsies with subsequent treatment for cervical intraepithelial neoplasia grade II or III and cytological surveillance for grade I or less provides the best balance between benefits and harms for the management of women with low grade abnormal cytology referred for colposcopy. Immediate large loop excision results in overtreatment and more after effects and should not be recommended. ISRCTN 34841617.

26 CFR 53.4965-3 - Prohibited tax shelter transactions.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 26 Internal Revenue 17 2011-04-01 2011-04-01 false Prohibited tax shelter transactions. 53.4965-3...) MISCELLANEOUS EXCISE TAXES (CONTINUED) FOUNDATION AND SIMILAR EXCISE TAXES Second Tier Excise Taxes § 53.4965-3 Prohibited tax shelter transactions. (a) In general. Under section 4965(e), the term prohibited tax shelter...

27 CFR 24.323 - Excise Tax Return form.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Excise Tax Return form. 24.323 Section 24.323 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS WINE Records and Reports § 24.323 Excise Tax Return form. A proprietor who...

29 CFR 794.121 - Exclusion of excise taxes.

Code of Federal Regulations, 2010 CFR

2010-07-01

... From Overtime Pay Requirements Under Section 7(b)(3) of the Act Annual Gross Volume of Sales § 794.121 Exclusion of excise taxes. The computation of the annual gross volume of sales of the enterprise for... excise taxes which are included in the sales price may be excluded in computing the annual gross volume...

26 CFR 53.4952-1 - Black lung trusts-taxes on taxable expenditures.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 26 Internal Revenue 17 2011-04-01 2011-04-01 false Black lung trusts-taxes on taxable expenditures... (CONTINUED) MISCELLANEOUS EXCISE TAXES (CONTINUED) FOUNDATION AND SIMILAR EXCISE TAXES Black Lung Benefit Trust Excise Taxes § 53.4952-1 Black lung trusts—taxes on taxable expenditures. (a) In general. Section...

26 CFR 53.4951-1 - Black lung trusts-taxes on self-dealing.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 17 2010-04-01 2010-04-01 false Black lung trusts-taxes on self-dealing. 53... (CONTINUED) MISCELLANEOUS EXCISE TAXES (CONTINUED) FOUNDATION AND SIMILAR EXCISE TAXES Black Lung Benefit Trust Excise Taxes § 53.4951-1 Black lung trusts—taxes on self-dealing. (a) In general. Section 4951...

26 CFR 53.4951-1 - Black lung trusts-taxes on self-dealing.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 26 Internal Revenue 17 2011-04-01 2011-04-01 false Black lung trusts-taxes on self-dealing. 53... (CONTINUED) MISCELLANEOUS EXCISE TAXES (CONTINUED) FOUNDATION AND SIMILAR EXCISE TAXES Black Lung Benefit Trust Excise Taxes § 53.4951-1 Black lung trusts—taxes on self-dealing. (a) In general. Section 4951...

26 CFR 53.4952-1 - Black lung trusts-taxes on taxable expenditures.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 17 2010-04-01 2010-04-01 false Black lung trusts-taxes on taxable expenditures... (CONTINUED) MISCELLANEOUS EXCISE TAXES (CONTINUED) FOUNDATION AND SIMILAR EXCISE TAXES Black Lung Benefit Trust Excise Taxes § 53.4952-1 Black lung trusts—taxes on taxable expenditures. (a) In general. Section...

Aerodynamic and Nonlinear Dynamic Acoustic Analysis of Tension Asymmetry in Excised Canine Larynges

ERIC Educational Resources Information Center

Devine, Erin E.; Bulleit, Erin E.; Hoffman, Matthew R.; McCulloch, Timothy M.; Jiang, Jack J.

2012-01-01

Purpose: To model tension asymmetry caused by superior laryngeal nerve paralysis (SLNP) in excised larynges and apply perturbation, nonlinear dynamic, and aerodynamic analyses. Method: SLNP was modeled in 8 excised larynges using sutures and weights to mimic cricothyroid (CT) muscle function. Weights were removed from one side to create tension…

Exonuclease of human DNA polymerase gamma disengages its strand displacement function.

PubMed

He, Quan; Shumate, Christie K; White, Mark A; Molineux, Ian J; Yin, Y Whitney

2013-11-01

Pol γ, the only DNA polymerase found in human mitochondria, functions in both mtDNA repair and replication. During mtDNA base-excision repair, gaps are created after damaged base excision. Here we show that Pol γ efficiently gap-fills except when the gap is only a single nucleotide. Although wild-type Pol γ has very limited ability for strand displacement DNA synthesis, exo(-) (3'-5' exonuclease-deficient) Pol γ has significantly high activity and rapidly unwinds downstream DNA, synthesizing DNA at a rate comparable to that of the wild-type enzyme on a primer-template. The catalytic subunit Pol γA alone, even when exo(-), is unable to synthesize by strand displacement, making this the only known reaction of Pol γ holoenzyme that has an absolute requirement for the accessory subunit Pol γB. © 2013. Published by Elsevier B.V.

Staged marginal contoured and central excision technique in the surgical management of perianal Paget's disease.

PubMed

Möller, Mecker G; Lugo-Baruqui, Jose Alejandro; Milikowski, Clara; Salgado, Christopher J

2014-04-01

Extramammary Paget's disease (EMPD) is an adenocarcinoma of the apocrine glands with unknown exact prevalence and obscure etiology. It has been divided into primary EMPD and secondary EMPD, in which an internal malignancy is usually associated. Treatment for primary EMPD usually consists of wide lesion excision with negative margins. Multiple methods have been proposed to obtain free-margin status of the disease. These include visible border lesion excision, punch biopsies, and micrographic and frozen-section surgery, with different results but still high recurrence rates. The investigators propose a method consisting of a staged contoured marginal excision using "en face" permanent pathologic analysis preceding the steps of central excision of the lesion and the final reconstruction of the surgical defect. Advantages of this method include adequate margin control allowing final reconstruction and tissue preservation, while minimizing patient discomfort. The staged contoured marginal and central excision technique offers a new alternative to the armamentarium for surgical oncologists for the management of EMPD in which margin control is imperative for control of recurrence rates. Copyright © 2014 Elsevier Inc. All rights reserved.

Rational Inhibitors of DNA Base Excision Repair (BER) Enzymes: New Tools for Elucidating the Role of the BER in Cancer Chemotherapy

DTIC Science & Technology

2005-05-01

Revised Manuscript Received March 3, 2005 ABSTRACT: Base flipping is a highly conserved strategy used by enzymes to gain catalytic access to DNA bases that...73.13. Jencks, W. P. (1985) A primer for the bema hapothle-an between uracil and other normal DNA bases at this inter- empirical-approach to the

Fe-S Clusters and MutY Base Excision Repair Glycosylases: Purification, Kinetics, and DNA Affinity Measurements.

PubMed

Nuñez, Nicole N; Majumdar, Chandrima; Lay, Kori T; David, Sheila S

2018-01-01

A growing number of iron-sulfur (Fe-S) cluster cofactors have been identified in DNA repair proteins. MutY and its homologs are base excision repair (BER) glycosylases that prevent mutations associated with the common oxidation product of guanine (G), 8-oxo-7,8-dihydroguanine (OG) by catalyzing adenine (A) base excision from inappropriately formed OG:A mispairs. The finding of an [4Fe-4S] 2+ cluster cofactor in MutY, Endonuclease III, and structurally similar BER enzymes was surprising and initially thought to represent an example of a purely structural role for the cofactor. However, in the two decades subsequent to the initial discovery, purification and in vitro analysis of bacterial MutYs and mammalian homologs, such as human MUTYH and mouse Mutyh, have demonstrated that proper Fe-S cluster coordination is required for OG:A substrate recognition and adenine excision. In addition, the Fe-S cluster in MutY has been shown to be capable of redox chemistry in the presence of DNA. The work in our laboratory aimed at addressing the importance of the MutY Fe-S cluster has involved a battery of approaches, with the overarching hypothesis that understanding the role(s) of the Fe-S cluster is intimately associated with understanding the biological and chemical properties of MutY and its unique damaged DNA substrate as a whole. In this chapter, we focus on methods of enzyme expression and purification, detailed enzyme kinetics, and DNA affinity assays. The methods described herein have not only been leveraged to provide insight into the roles of the MutY Fe-S cluster but have also been provided crucial information needed to delineate the impact of inherited variants of the human homolog MUTYH associated with a colorectal cancer syndrome known as MUTYH-associated polyposis or MAP. Notably, many MAP-associated variants have been found adjacent to the Fe-S cluster further underscoring the intimate relationship between the cofactor, MUTYH-mediated DNA repair, and disease. © 2018 Elsevier Inc. All rights reserved.

Stuck in Neutral: Stalled Progress in Statewide Comprehensive Smoke-Free Laws and Cigarette Excise Taxes, United States, 2000–2014

PubMed Central

King, Brian A.; Babb, Stephen D.

2016-01-01

Introduction Increasing tobacco excise taxes and implementing comprehensive smoke-free laws are two of the most effective population-level strategies to reduce tobacco use, prevent tobacco use initiation, and protect nonsmokers from secondhand smoke. We examined state laws related to smoke-free buildings and to cigarette excise taxes from 2000 through 2014 to see how implementation of these laws from 2000 through 2009 differs from implementation in more recent years (2010–2014). Methods We used legislative data from LexisNexis, an online legal research database, to examine changes in statewide smoke-free laws and cigarette excise taxes in effect from January 1, 2000, through December 31, 2014. A comprehensive smoke-free law was defined as a statewide law prohibiting smoking in all indoor areas of private work sites, restaurants, and bars. Results From 2000 through 2009, 21 states and the District of Columbia implemented comprehensive smoke-free laws prohibiting smoking in work sites, restaurants, and bars. In 2010, 4 states implemented comprehensive smoke-free laws. The last state to implement a comprehensive smoke-free law was North Dakota in 2012, bringing the total number to 26 states and the District of Columbia. From 2000 through 2009, 46 states and the District of Columbia implemented laws increasing their cigarette excise tax, which increased the national average state excise tax rate by $0.92. However, from 2010 through 2014, only 14 states and the District of Columbia increased their excise tax, which increased the national average state excise tax rate by $0.20. Conclusion The recent stall in progress in enacting and implementing statewide comprehensive smoke-free laws and increasing cigarette excise taxes may undermine tobacco prevention and control efforts in the United States, undercutting efforts to reduce tobacco use, exposure to secondhand smoke, health disparities, and tobacco-related illness and death. PMID:27309417

Stuck in Neutral: Stalled Progress in Statewide Comprehensive Smoke-Free Laws and Cigarette Excise Taxes, United States, 2000-2014.

PubMed

Holmes, Carissa Baker; King, Brian A; Babb, Stephen D

2016-06-16

Increasing tobacco excise taxes and implementing comprehensive smoke-free laws are two of the most effective population-level strategies to reduce tobacco use, prevent tobacco use initiation, and protect nonsmokers from secondhand smoke. We examined state laws related to smoke-free buildings and to cigarette excise taxes from 2000 through 2014 to see how implementation of these laws from 2000 through 2009 differs from implementation in more recent years (2010-2014). We used legislative data from LexisNexis, an online legal research database, to examine changes in statewide smoke-free laws and cigarette excise taxes in effect from January 1, 2000, through December 31, 2014. A comprehensive smoke-free law was defined as a statewide law prohibiting smoking in all indoor areas of private work sites, restaurants, and bars. From 2000 through 2009, 21 states and the District of Columbia implemented comprehensive smoke-free laws prohibiting smoking in work sites, restaurants, and bars. In 2010, 4 states implemented comprehensive smoke-free laws. The last state to implement a comprehensive smoke-free law was North Dakota in 2012, bringing the total number to 26 states and the District of Columbia. From 2000 through 2009, 46 states and the District of Columbia implemented laws increasing their cigarette excise tax, which increased the national average state excise tax rate by $0.92. However, from 2010 through 2014, only 14 states and the District of Columbia increased their excise tax, which increased the national average state excise tax rate by $0.20. The recent stall in progress in enacting and implementing statewide comprehensive smoke-free laws and increasing cigarette excise taxes may undermine tobacco prevention and control efforts in the United States, undercutting efforts to reduce tobacco use, exposure to secondhand smoke, health disparities, and tobacco-related illness and death.

A Hyalinized Trichilemmoma of the Eyelid in a Teenager.

PubMed

Jakobiec, Frederick A; Stagner, Anna M; Sassoon, Jodi; Goldstein, Scott; Mihm, Martin C

2016-01-01

A 16-year-old African American male, the youngest patient to date, presented with a well-circumscribed upper eyelid lesion. On excision, the dermal nodule was contiguous with the epidermis, displayed trichohyalin-like bodies in an expanded outer root sheath, and was composed chiefly of small cellular clusters separated by a prominent network of periodic acid Schiff -positive hyaline bands of basement membrane material. The tumor cells were positive for high molecular weight cytokeratins (CK) 5/6, CK14, and CK34βE12 and were negative for CK7, carcinoembryonic antigen and epithelial membrane antigen. Negative S100, glial fibrillary acidic protein, and smooth muscle actin immunoreactions ruled out a myoepithelial lesion. The Ki-67 proliferation index was <10%. The diagnosis was a hyalinized trichilemmoma, contrasting with the more common lobular type. As an isolated lesion, trichilemmoma does not portend Cowden syndrome.

Effects of suspension on tissue levels of glucocorticoid receptors

NASA Technical Reports Server (NTRS)

Steffen, J. M.

1984-01-01

Differential muscle responses can be simulated by hypokinetic/hypodynamic (H/H) suspension of rats with complete unloading of the hindlimb muscles. Since mechanism(s) underlying these atrophic effects were not clearly elucidated, experiments were initiated to investigate a possible role for glucocorticoids in the physiological and biochemical responses to H/H. The principal objective was to assess the potential for alterations in peripheral responsiveness to glucocorticoids in response to H/H. Studies have initially focused on the determination of tissue levels of glucocorticoid receptors as one index of hormonal sensitivity at the cellular level. Four hindlimb muscles (soleus, gastrocnemius, plantaris and EDL), previously demonstrated to exhibit differential responses to H/H, were investigated. Receptor levels in other glucocorticoid sensitive tissues (heart, liver, and kidney) were determined. Male rats (180-200g) were suspended for 7 or 14 days, sacrificed by cervical dislocation, and the tissues excised.

SON is a spliceosome-associated factor required for mitotic progression.

PubMed

Huen, Michael S Y; Sy, Shirley M H; Leung, Ka Man; Ching, Yick-Pang; Tipoe, George L; Man, Cornelia; Dong, Shuo; Chen, Junjie

2010-07-01

The eukaryotic RNA splicing machinery is dedicated to the daunting task of excising intronic sequences on the many nascent RNA transcripts in a cell, and in doing so facilitates proper translation of its transcriptome. Notably, emerging evidence suggests that RNA splicing may also play direct roles in maintaining genome stability. Here we report the identification of the RNA/DNA-binding protein SON as a component of spliceosome that plays pleiotropic roles during mitotic progression. We found that SON is essential for cell proliferation, and that its inactivation triggers a MAD2-dependent mitotic delay. Moreover, SON deficiency is accompanied by defective chromosome congression, compromised chromosome segregation and cytokinesis, which in turn contributes to cellular aneuploidy and cell death. In summary, our study uncovers a specific link between SON and mitosis, and highlights the potential of RNA processing as additional regulatory mechanisms that govern cell proliferation and division. © 2010 Landes Bioscience

SON is a spliceosome-associated factor required for mitotic progression

PubMed Central

Sy, Shirley MH; Leung, Ka Man; Ching, Yick-Pang; Tipoe, George L; Man, Cornelia; Dong, Shuo

2010-01-01

The eukaryotic RNA splicing machinery is dedicated to the daunting task of excising intronic sequences on the many nascent RNA transcripts in a cell, and in doing so facilitates proper translation of its transcriptome. Notably, emerging evidence suggests that RNA splicing may also play direct roles in maintaining genome stability. Here we report the identification of the RNA/DNA-binding protein SON as a component of spliceosome that plays pleiotropic roles during mitotic progression. We found that SON is essential for cell proliferation, and that its inactivation triggers a MAD2-dependent mitotic delay. Moreover, SON deficiency is accompanied by defective chromosome congression, compromised chromosome segregation and cytokinesis, which in turn contributes to cellular aneuploidy and cell death. In summary, our study uncovers a specific link between SON and mitosis, and highlights the potential of RNA processing as additional regulatory mechanisms that govern cell proliferation and division. PMID:20581448

Hereditary Disorders with Defective Repair of UV-Induced DNA Damage

PubMed Central

Moriwaki, Shinichi

2013-01-01

Nucleotide excision repair (NER) is an essential system for correcting ultraviolet (UV)—induced DNA damage. Lesions remaining in DNA due to reduced capacity of NER may result in cellular death, premature aging, mutagenesis and carcinogenesis of the skin. So, NER is an important protection against these changes. There are three representative genodermatoses resulting from genetic defects in NER: xeroderma pigmentosum (XP), Cockayne syndrome (CS), and trichothiodystrophy (TTD). In Japan, CS is similarly rare but XP is more common and TTD is less common compared to Western countries. In 1998, we established the system for the diagnosis of these disorders and we have been performing DNA repair and genetic analysis for more than 400 samples since then. At present, there is no cure for any human genetic disorder. Early diagnosis and symptomatic treatment of neurological, ocular and dermatological abnormalities should contribute to prolonging life and elevating QOL in patients. PMID:23966815

Non-invasive imaging of skin cancer with fluorescence lifetime imaging using two photon tomography

NASA Astrophysics Data System (ADS)

Patalay, Rakesh; Talbot, Clifford; Alexandrov, Yuriy; Munro, Ian; Breunig, Hans Georg; König, Karsten; Warren, Sean; Neil, Mark A. A.; French, Paul M. W.; Chu, Anthony; Stamp, Gordon W.; Dunsby, Christopher

2011-07-01

Multispectral fluorescence lifetime imaging (FLIM) using two photon microscopy as a non-invasive technique for the diagnosis of skin lesions is described. Skin contains fluorophores including elastin, keratin, collagen, FAD and NADH. This endogenous contrast allows tissue to be imaged without the addition of exogenous agents and allows the in vivo state of cells and tissues to be studied. A modified DermaInspect® multiphoton tomography system was used to excite autofluorescence at 760 nm in vivo and on freshly excised ex vivo tissue. This instrument simultaneously acquires fluorescence lifetime images in four spectral channels between 360-655 nm using time-correlated single photon counting and can also provide hyperspectral images. The multispectral fluorescence lifetime images were spatially segmented and binned to determine lifetimes for each cell by fitting to a double exponential lifetime model. A comparative analysis between the cellular lifetimes from different diagnoses demonstrates significant diagnostic potential.

Evaluation of the SAVI SCOUT Surgical Guidance System for Localization and Excision of Nonpalpable Breast Lesions: A Feasibility Study.

PubMed

Mango, Victoria; Ha, Richard; Gomberawalla, Ameer; Wynn, Ralph; Feldman, Sheldon

2016-06-15

The purpose of this study is to evaluate the feasibility of the SAVI SCOUT surgical guidance system, which uses a nonradioactive infrared-activated electromagnetic wave reflector, to localize and excise nonpalpable breast lesions. We evaluated the system's use in 15 nonpalpable breast lesions in 13 patients. Image-guided placement was successful for 15 of 15 (100%) reflectors. The final pathologic analysis found that lesion excision was successful, including five malignancies with negative margins. No patients required reexcision or experienced complications. SAVI SCOUT is a feasible method for breast lesion localization and excision.

High Rate of Osteoarthritis After Osteochondritis Dissecans Fragment Excision Compared With Surgical Restoration at a Mean 16-Year Follow-up.

PubMed

Sanders, Thomas L; Pareek, Ayoosh; Obey, Mitchel R; Johnson, Nicholas R; Carey, James L; Stuart, Michael J; Krych, Aaron J

2017-07-01

Osteochondritis dissecans (OCD) is a disorder of subchondral bone that causes adverse effects on the overlying cartilage and commonly affects the knee. The incidence of OCD and its long-term effect on the knee joint are controversial. Hypothesis/Purpose: The purpose of this study was to (1) evaluate the rate of osteoarthritis and knee arthroplasty in a population-based cohort of patients with OCD lesions treated operatively and (2) evaluate factors that may predispose patients to knee osteoarthritis and arthroplasty. The investigators hypothesized that OCD lesions diagnosed after skeletal maturity and treatment with fragment excision would be predictive of a diagnosis of osteoarthritis. Cohort study; Level of evidence, 3. The investigators identified 221 patients (mean ± SD age, 26.1 ± 13.6 years) with OCD lesions treated operatively between 1976 and 2010 and followed for 16.3 ± 11.4 years (mean ± SD) from diagnosis. Information related to the diagnosis, laterality of lesion, details of treatment, and progression to osteoarthritis was obtained from the medical record. Surgical treatment was classified as fragment excision, fragment preservation (lesion drilling and/or fragment fixation), or chondral defect grafting (osteochondral allograft or autograft). Factors predictive of osteoarthritis and arthroplasty were examined. There were 134 patients in the fragment excision group, 78 patients in the fragment preservation group, and 9 patients in the chondral defect grafting group. In the fragment excision group, the cumulative incidence of osteoarthritis was 12.0% at 5 years, 17.0% at 10 years, 26.0% at 15 years, 39.0% at 20 years, and 70% at 30 years. The cumulative incidence of arthroplasty was 2.0% at 5 years, 4.0% at 10 years, 4.0% at 15 years, 10.0% at 20 years, and 32.0% at 30 years. In the fragment preservation group, the cumulative incidence of osteoarthritis was 3.0% at 5 years, 7.0% at 10 years, 16.0% at 15 years, 25.0% at 20 years, and 51% at 30 years. The cumulative incidence of arthroplasty was 0.0% at 5 years, 0.0% at 10 years, 3.0% at 15 years, 6.0% at 20 years, and 11.0% at 30 years. No patients in the chondral defect grafting group developed osteoarthritis or underwent arthroplasty. Body mass index (BMI) greater than 25 kg/m 2 (hazard ratio [HR] 3.3; 95% CI, 1.6-7.0), older age at diagnosis (HR 4.9; 95% CI, 1.8-17.3), and fragment excision (HR 2.3; 95% CI, 1.2-4.6) were predictive of osteoarthritis. OCD patients treated with fragment excision have a high rate of osteoarthritis and knee arthroplasty at long-term follow-up. In contrast, patients treated with fragment preservation or chondral defect grafting have lower rates of osteoarthritis and arthroplasty. BMI greater than 25 kg/m 2 , older age at diagnosis, and fragment excision were predictive of osteoarthritis.

Base excision DNA repair in the embryonic development of the sea urchin, Strongylocentrotus intermedius.

PubMed

Torgasheva, Natalya A; Menzorova, Natalya I; Sibirtsev, Yurii T; Rasskazov, Valery A; Zharkov, Dmitry O; Nevinsky, Georgy A

2016-06-21

In actively proliferating cells, such as the cells of the developing embryo, DNA repair is crucial for preventing the accumulation of mutations and synchronizing cell division. Sea urchin embryo growth was analyzed and extracts were prepared. The relative activity of DNA polymerase, apurinic/apyrimidinic (AP) endonuclease, uracil-DNA glycosylase, 8-oxoguanine-DNA glycosylase, and other glycosylases was analyzed using specific oligonucleotide substrates of these enzymes; the reaction products were resolved by denaturing 20% polyacrylamide gel electrophoresis. We have characterized the profile of several key base excision repair activities in the developing embryos (2 blastomers to mid-pluteus) of the grey sea urchin, Strongylocentrotus intermedius. The uracil-DNA glycosylase specific activity sharply increased after blastula hatching, whereas the specific activity of 8-oxoguanine-DNA glycosylase steadily decreased over the course of the development. The AP-endonuclease activity gradually increased but dropped at the last sampled stage (mid-pluteus 2). The DNA polymerase activity was high at the first cleavage division and then quickly decreased, showing a transient peak at blastula hatching. It seems that the developing sea urchin embryo encounters different DNA-damaging factors early in development within the protective envelope and later as a free-floating larva, with hatching necessitating adaptation to the shift in genotoxic stress conditions. No correlation was observed between the dynamics of the enzyme activities and published gene expression data from developing congeneric species, S. purpuratus. The results suggest that base excision repair enzymes may be regulated in the sea urchin embryos at the level of covalent modification or protein stability.

Assessment of HER2 status in breast cancer biopsies is not affected by accelerated tissue processing.

PubMed

Bulte, Joris P; Halilovic, Altuna; Kalkman, Shona; van Cleef, Patricia H J; van Diest, Paul J; Strobbe, Luc J A; de Wilt, Johannes H W; Bult, Peter

2018-03-01

To establish whether core needle biopsy (CNB) specimens processed with an accelerated processing method with short fixation time can be used to determine accurately the human epidermal growth factor receptor 2 (HER2) status of breast cancer. A consecutive case-series from two high-volume breast clinics was created. We compared routine HER2 immunohistochemistry (IHC) assessment between accelerated processing CNB specimens and routinely processed postoperative excision specimens. Additional amplification-based testing was performed in cases with equivocal results. The formalin fixation time was less than 2 h and between 6 and 72 h, respectively. Fluorescence in-situ hybridisation and multiplex ligation-dependent probe amplification were used for amplification testing. One hundred and forty-four cases were included, 15 of which were HER2-positive on the routinely processed excision specimens. On the CNB specimens, 44 were equivocal on IHC and required an amplification-based test. Correlation between the CNB specimens and the corresponding excision specimens was high for final HER2 status, with an accuracy of 97% and a kappa of 0.85. HER2 status can be determined reliably on CNB specimens with accelerated processing time using standard clinical testing methods. Using this accelerated technology the minimum 6 h of formalin fixation, which current guidelines consider necessary, can be decreased safely. This allows for a complete and expedited histology-based diagnosis of breast lesions in the setting of a one-stop-shop, same-day breast clinic. © 2018 The Authors. Histopathology Published by John Wiley & Sons Ltd.

The potential of liquid-based cytology in lymph node cytological evaluation: the role of morphology and the aid of ancillary techniques.

PubMed

Rossi, E D; Martini, M; Straccia, P; Bizzarro, T; Fadda, G; Larocca, L M

2016-02-01

Our aim was to evaluate the feasibility and diagnostic accuracy of liquid-based cytology (LBC) on lymph node fine needle aspiration (FNA). FNA may fulfil a challenging role in the evaluation of the majority of primary (benign and malignant) diagnoses as well as metastatic lymph node lesions. Although the morphological features may be quite easily recognized, cytological samples with a scant cellular component may raise some issues. We appraised 263 cytological lymph nodes from different body regions analysed between January and December 2013, including 137 male and 126 female patients, and processed with LBC. The cytological diagnoses included 160 benign and 103 malignant lesions. We reported 35 benign and 73 malignant lesions from 108 with surgical follow-up. The latter malignant series included 68 metastatic lesions, four suspicious for malignancy and one inadequate sample. The cytological diagnoses were supported by 62 conclusive immunocytochemical and 28 molecular analyses. Of the 108 cases, we documented 35 true negatives, 72 true positives, one false negative and no false positives, resulting in 98.6% sensitivity, 100% specificity, 99% diagnostic accuracy, 97.2% negative predictive value and 100% positive predictive value. FNA represents the first diagnostic tool in lymph node management and a reliable approach in order to avoid an excision biopsy. Furthermore, LBC is a feasible method for ancillary tests for which methanol-fixed samples are suitable, such as immunocytochemistry and molecular analysis. © 2014 John Wiley & Sons Ltd.

Impact of surgical margins on survival of 37 dogs with massive hepatocellular carcinoma.

PubMed

Matsuyama, A; Takagi, S; Hosoya, K; Kagawa, Y; Nakamura, K; Deguchi, T; Takiguchi, M

2017-09-01

To compare the survival of dogs with completely resected massive hepatocellular carcinoma (HCC) with that of dogs in which HCC were incompletely excised. A retrospective cohort study was conducted. Dogs that underwent surgical excision of massive HCC between November 2006 and April 2015 were included. Dogs that died in the perioperative period or were lost to follow-up within 2 months after surgery were excluded. Data were collected from the medical records and a single pathologist examined all available histology slides to confirm the diagnosis of HCC. Surgical margins were defined as complete if no neoplastic cells were seen at the edge of excised tissues, based on original histopathology reports. Progression-free survival (PFS) and overall survival (OS) were compared between dogs with complete surgical margins (CM) and those with incomplete margins (IM) using a log-rank test. Of the 37 dogs included in the study, 25 were allocated to the CM group and 12 to the IM group. Progressive local disease developed after surgery in three dogs in the CM group and seven dogs in the IM group. Three dogs in the CM group and five dogs in the IM group died due to tumour progression. Median PFS was longer for dogs in the CM group (1,000 (95% CI=562-1,438) days) compared to dogs in the IM group (521 (95% CI=243-799) days; p=0.007). OS was also longer for dogs in the CM group (>1,836 days) compared to those in the IM group (median 765 (95% CI=474-1,056) days; p=0.02). Compared with complete resection, incomplete resection decreased PFS and OS in dogs with massive HCC. Dogs with incompletely excised HCC should be closely monitored for local recurrence, although median OS was >2 years following incomplete excision. Further prospective studies are warranted to confirm these findings.

Biophysical interpretation and ex-vivo characterization of scattered light from tumor-associated breast stroma

NASA Astrophysics Data System (ADS)

Laughney, Ashley; Krishnaswamy, Venkat; Schwab, Mary; Wells, Wendy A.; Paulsen, Keith D.; Pogue, Brian W.

2009-02-01

The purpose of this study was to extract scatter parameters related to tissue ultra-structures from freshly excised breast tissue and to assess whether evident changes in scatter across diagnostic categories is primarily influenced by variation in the composition of each tissues subtypes or by physical remodeling of the extra-cellular environment. Pathologists easily distinguish between epithelium, stroma and adipose tissues, so this classification was adopted for macroscopic subtype classification. Micro-sampling reflectance spectroscopy was used to characterize single-backscattered photons from fresh, excised tumors and normal reduction specimens with sub-millimeter resolution. Phase contrast microscopy (sub-micron resolution) was used to characterize forward-scattered light through frozen tissue from the DHMC Tissue Bank, representing normal, benign and malignant breast tissue, sectioned at 10 microns. The packing density and orientation of collagen fibers in the extracellular matrix (ECM) associated with invasive, normal and benign epithelium was evaluated using transmission electron microscopy (TEM). Regions of interest (ROIs) in the H&E stained tissues were identified for analysis, as outlined by a pathologist as the gold standard. We conclude that the scatter parameters associated with tumor specimens (Npatients=6, Nspecimens=13) significantly differs from that of normal reductions (Npatients=6, Nspecimens=10). Further, tissue subtypes may be identified by their scatter spectra at sub-micron resolution. Stromal tissue scatters significantly more than the epithelial cells embedded in its ECM and adipose tissue scatters much less. However, the scatter signature of the stroma at the sub-micron level is not particularly differentiating in terms of a diagnosis.

Nucleotide Excision Repair and Vitamin D--Relevance for Skin Cancer Therapy.

PubMed

Pawlowska, Elzbieta; Wysokinski, Daniel; Blasiak, Janusz

2016-04-06

Ultraviolet (UV) radiation is involved in almost all skin cancer cases, but on the other hand, it stimulates the production of pre-vitamin D3, whose active metabolite, 1,25-dihydroxyvitamin D3 (1,25VD3), plays important physiological functions on binding with its receptor (vitamin D receptor, VDR). UV-induced DNA damages in the form of cyclobutane pyrimidine dimers or (6-4)-pyrimidine-pyrimidone photoproducts are frequently found in skin cancer and its precursors. Therefore, removing these lesions is essential for the prevention of skin cancer. As UV-induced DNA damages are repaired by nucleotide excision repair (NER), the interaction of 1,25VD3 with NER components can be important for skin cancer transformation. Several studies show that 1,25VD3 protects DNA against damage induced by UV, but the exact mechanism of this protection is not completely clear. 1,25VD3 was also shown to affect cell cycle regulation and apoptosis in several signaling pathways, so it can be considered as a potential modulator of the cellular DNA damage response, which is crucial for mutagenesis and cancer transformation. 1,25VD3 was shown to affect DNA repair and potentially NER through decreasing nitrosylation of DNA repair enzymes by NO overproduction by UV, but other mechanisms of the interaction between 1,25VD3 and NER machinery also are suggested. Therefore, the array of NER gene functioning could be analyzed and an appropriate amount of 1.25VD3 could be recommended to decrease UV-induced DNA damage important for skin cancer transformation.

Direct, Differential Effects of Tamoxifen, 4-Hydroxytamoxifen, and Raloxifene on Cardiac Myocyte Contractility and Calcium Handling

PubMed Central

Asp, Michelle L.; Martindale, Joshua J.; Metzger, Joseph M.

2013-01-01

Tamoxifen (Tam), a selective estrogen receptor modulator, is in wide clinical use for the treatment and prevention of breast cancer. High Tam doses have been used for treatment of gliomas and cancers with multiple drug resistance, but long QT Syndrome is a side effect. Tam is also used experimentally in mice for inducible gene knockout in numerous tissues, including heart; however, the potential direct effects of Tam on cardiac myocyte mechanical function are not known. The goal of this study was to determine the direct, acute effects of Tam, its active metabolite 4-hydroxytamoxifen (4OHT), and related drug raloxifene (Ral) on isolated rat cardiac myocyte mechanical function and calcium handling. Tam decreased contraction amplitude, slowed relaxation, and decreased Ca2+ transient amplitude. Effects were primarily observed at 5 and 10 μM Tam, which is relevant for high dose Tam treatment in cancer patients as well as Tam-mediated gene excision in mice. Myocytes treated with 4OHT responded similarly to Tam-treated cells with regard to both contractility and calcium handling, suggesting an estrogen-receptor independent mechanism is responsible for the effects. In contrast, Ral increased contraction and Ca2+ transient amplitudes. At 10 μM, all drugs had a time-dependent effect to abolish cellular contraction. In conclusion, Tam, 4OHT, and Ral adversely and differentially alter cardiac myocyte contractility and Ca2+ handling. These findings have important implications for understanding the Tam-induced cardiomyopathy in gene excision studies and may be important for understanding effects on cardiac performance in patients undergoing high-dose Tam therapy. PMID:24205315

Spectrally Encoded Confocal Microscopy (SECM) for Diagnosing of Breast Cancer in Excision and Margin Specimens

PubMed Central

Brachtel, Elena F.; Johnson, Nicole B.; Huck, Amelia E.; Rice-Stitt, Travis L.; Vangel, Mark G.; Smith, Barbara L.; Tearney, Guillermo J.; Kang, Dongkyun

2016-01-01

A large percentage of breast cancer patients treated with breast conserving surgery need to undergo multiple surgeries due to positive margins found during post-operative margin assessment. Carcinomas could be removed completely during the initial surgery and additional surgery avoided if positive margins can be determined intra-operatively. Spectrally-encoded confocal microscopy (SECM) is a high-speed reflectance confocal microscopy technology that has a potential to rapidly image the entire surgical margin at sub-cellular resolution and accurately determine margin status intra-operatively. In this paper, in order to test feasibility of using SECM for intra-operative margin assessment, we have evaluated the diagnostic accuracy of SECM for detecting various types of breast cancers. Forty-six surgically-removed breast specimens were imaged with a SECM system. Side-by-side comparison between SECM and histologic images showed that SECM images can visualize key histomorphologic patterns of normal/benign and malignant breast tissues. Small (500 µm × 500 µm) spatially-registered SECM and histologic images (n=124 for each) were diagnosed independently by three pathologists with expertise in breast pathology. Diagnostic accuracy of SECM for determining malignant tissues was high, average sensitivity of 0.91, specificity of 0.93, positive predictive value of 0.95, and negative predictive value of 0.87. Intra-observer agreement and inter-observer agreement for SECM were also high, 0.87 and 0.84, respectively. Results from this study suggest that SECM may be developed into an intra-operative margin assessment tool for guiding breast cancer excisions. PMID:26779830

Oxygen Transport and Root Respiration of Maize Seedlings

PubMed Central

Saglio, Pierre H.; Raymond, Philippe; Pradet, Alain

1983-01-01

Oxygen uptake and ATP/ADP ratio were simultaneously monitored during incubation of excised maize (Zea mays L. INRA 508) root tips under varying O2 partial pressure. Both variables were independent of O2 tension until a critical O2 pressure was reached. Below this pressure, ATP/ADP ratio and respiratory rate declined. However, in tissues having a high glycolytic capacity, the correlation between the ATP/ADP ratio and the respiratory rate breaks down as O2 tension decreases, due to the increasing contribution of fermentative processes. In presence of 2 millimolar NaF, the ATP/ADP ratio varied solely as a function of the O2 tension, without interference by fermentative activity, and a close correlation links the ATP/ADP ratio and the respiratory rate of excised maize root tips over the whole range of O2 tensions tested. Using this correlation, a method is proposed for the quantitative determination of the relative cellular respiratory rate permitted by O2 transport from the aerial part of young maize seedlings along the seminal root placed in an anoxic environment. Data are presented which demonstrate the preeminent part played by the cortical air spaces in O2 transport. Their contribution to respiration was high in the first few centimeters nearest the seed and decreased rapidly as the distance from the aerated source increased. It is concluded that O2 transport might contribute to the survival or to adaptive responses of root tissues in flooded soils but that the ventilation of the apical growing zone was inadequate to sustain the growth. PMID:16663116

Mutations in Replicative Stress Response Pathways Are Associated with S Phase-specific Defects in Nucleotide Excision Repair*

PubMed Central

Bélanger, François; Angers, Jean-Philippe; Fortier, Émile; Hammond-Martel, Ian; Costantino, Santiago; Drobetsky, Elliot; Wurtele, Hugo

2016-01-01

Nucleotide excision repair (NER) is a highly conserved pathway that removes helix-distorting DNA lesions induced by a plethora of mutagens, including UV light. Our laboratory previously demonstrated that human cells deficient in either ATM and Rad3-related (ATR) kinase or translesion DNA polymerase η (i.e. key proteins that promote the completion of DNA replication in response to UV-induced replicative stress) are characterized by profound inhibition of NER exclusively during S phase. Toward elucidating the mechanistic basis of this phenomenon, we developed a novel assay to quantify NER kinetics as a function of cell cycle in the model organism Saccharomyces cerevisiae. Using this assay, we demonstrate that in yeast, deficiency of the ATR homologue Mec1 or of any among several other proteins involved in the cellular response to replicative stress significantly abrogates NER uniquely during S phase. Moreover, initiation of DNA replication is required for manifestation of this defect, and S phase NER proficiency is correlated with the capacity of individual mutants to respond to replicative stress. Importantly, we demonstrate that partial depletion of Rfa1 recapitulates defective S phase-specific NER in wild type yeast; moreover, ectopic RPA1–3 overexpression rescues such deficiency in either ATR- or polymerase η-deficient human cells. Our results strongly suggest that reduction of NER capacity during periods of enhanced replicative stress, ostensibly caused by inordinate sequestration of RPA at stalled DNA replication forks, represents a conserved feature of the multifaceted eukaryotic DNA damage response. PMID:26578521

26 CFR 53.4941(b)-1 - Imposition of additional taxes.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 26 Internal Revenue 17 2011-04-01 2011-04-01 false Imposition of additional taxes. 53.4941(b)-1...) MISCELLANEOUS EXCISE TAXES (CONTINUED) FOUNDATION AND SIMILAR EXCISE TAXES Taxes on Self-Dealing § 53.4941(b)-1 Imposition of additional taxes. (a) Tax on self-dealer. Section 4941(b)(1) of the Code imposes an excise tax...

75 FR 33888 - Proposed Collection; Comment Request for Regulation Project

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-15

... Gas, and PS-120-90 (TD 8241), Gasoline Excise Tax (Sec. Sec. 48.4041-21, 48.4081-2(c)(2), 48.4081-3(d... . SUPPLEMENTARY INFORMATION: Title: PS-66-93, Gasohol; Compressed Natural Gas; and PS-120-90, Gasoline Excise Tax...: This regulation relates to the federal excise tax on gasoline. It affects refiners, importers, and...

76 FR 3584 - Time for Payment of Certain Excise Taxes, and Quarterly Excise Tax Payments for Small Alcohol...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-20

... 40 Cigars and cigarettes, Claims, Electronic fund transfers, Excise taxes, Labeling, Packaging and..., Regulations.gov , we will post, and you may view, copies of this notice, any electronic or mailed comments we... material that we consider unsuitable for posting. You also may view copies of this notice, any electronic...

26 CFR 31.3402(t)-4 - Certain payments excepted from withholding.

Code of Federal Regulations, 2012 CFR

2012-04-01

... contemplated in the agreement. (n) Sales tax, excise tax, value-added tax, and other taxes. For purposes of this section, section 3402(t) withholding applies to any payment of sales tax, excise tax, value-added.... Notwithstanding the foregoing, the payment of sales tax, excise tax, value-added tax, or other tax may be excluded...

26 CFR 46.4701-1 - Tax on issuer of registration-required obligation not in registered form.

Code of Federal Regulations, 2010 CFR

2010-04-01

... obligation not in registered form. 46.4701-1 Section 46.4701-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) MISCELLANEOUS EXCISE TAXES EXCISE TAX ON POLICIES ISSUED BY FOREIGN INSURERS AND OBLIGATIONS NOT IN REGISTERED FORM Excise Tax on Obligations Not in Registered Form § 46.4701...

Estimated impacts of alternative Australian alcohol taxation structures on consumption, public health and government revenues.

PubMed

Doran, Christopher M; Byrnes, Joshua M; Cobiac, Linda J; Vandenberg, Brian; Vos, Theo

2013-11-04

To examine health and economic implications of modifying taxation of alcohol in Australia. Economic and epidemiological modelling of four scenarios for changing the current taxation of alcohol products, including: replacing the wine equalisation tax (WET) with a volumetric tax; applying an equal tax rate to all beverages equivalent to a 10% increase in the current excise applicable to spirits and ready-to-drink products; applying an excise tax rate that increases exponentially by 3% for every 1% increase in alcohol content above 3.2%; and applying a two-tiered volumetric tax. We used annual sales data and taxation rates for 2010 as the base case. Alcohol consumption, taxation revenue, disability-adjusted life-years (DALYs) averted and health care costs averted. In 2010, the Australian Government collected close to $8.6 billion from alcohol taxation. All four of the proposed variations to current rates of alcohol excise were shown to save money and more effectively reduce alcohol-related harm compared with the 2010 base case. Abolishing the WET and replacing it with a volumetric tax on wine would increase taxation revenue by $1.3 billion per year, reduce alcohol consumption by 1.3%, save $820 million in health care costs and avert 59 000 DALYs. The alternative scenarios would lead to even higher taxation receipts and greater reductions in alcohol use and harm. Our research findings suggest that any of the proposed variations to current rates of alcohol excise would be a cost-effective health care intervention; they thus reinforce the evidence that taxation is a cost-effective strategy. Of all the scenarios, perhaps the most politically feasible policy option at this point in time is to abolish the WET and replace it with a volumetric tax on wine. This analysis supports the recommendation of the National Preventative Health Taskforce and the Henry Review towards taxing alcohol according to alcohol content.

The effect of excise tax increases on cigarette prices in South Africa

PubMed Central

Linegar, Daniel J; van Walbeek, Corne

2018-01-01

Introduction The effectiveness of excise tax increases as a tool for reducing tobacco consumption depends largely on how the tax increases impact the retail price. We estimate this relationship in South Africa for 2001–2015. Data Statistics South Africa provided disaggregated cigarette price data, used in the calculation of the Consumers’ Price Index. Data on the excise tax per cigarette were obtained from Budget Reviews prepared by the National Treasury of South Africa. Methods Regression equations were estimated for each month. The month-on-month change in cigarette prices in February through April was regressed against March’s excise tax change to estimate the pass-through coefficient. For the other 9 months, the month-on-month change in cigarette price was regressed against monthly dummy variables to determine the size of the non-tax-related price increase in each of these months. The analysis was performed in both nominal and real (inflation-adjusted) terms. Findings Expressed in real terms, the excise tax was undershifted. A R1.00 (one rand) increase in the excise tax is associated with an increase in the retail price of cigarettes of R0.90 in the pre-2010 period, and R0.49 in the post-2010 period. In the pre-2010 period, the tobacco industry increased the retail price of cigarettes in July/August, independent of the excise tax increase. The discretionary July/August price increases largely disappeared after 2010, primarily because the market became more competitive. Conclusion The degree of excise tax pass-through, and the magnitude of discretionary increases in cigarette prices, is significantly determined by the competitive environment in the cigarette market. PMID:28341767

Beyond the excised ensemble: modelling elliptic curve L-functions with random matrices

NASA Astrophysics Data System (ADS)

Cooper, I. A.; Morris, Patrick W.; Snaith, N. C.

2016-02-01

The ‘excised ensemble’, a random matrix model for the zeros of quadratic twist families of elliptic curve L-functions, was introduced by Dueñez et al (2012 J. Phys. A: Math. Theor. 45 115207) The excised model is motivated by a formula for central values of these L-functions in a paper by Kohnen and Zagier (1981 Invent. Math. 64 175-98). This formula indicates that for a finite set of L-functions from a family of quadratic twists, the central values are all either zero or are greater than some positive cutoff. The excised model imposes this same condition on the central values of characteristic polynomials of matrices from {SO}(2N). Strangely, the cutoff on the characteristic polynomials that results in a convincing model for the L-function zeros is significantly smaller than that which we would obtain by naively transferring Kohnen and Zagier’s cutoff to the {SO}(2N) ensemble. In this current paper we investigate a modification to the excised model. It lacks the simplicity of the original excised ensemble, but it serves to explain the reason for the unexpectedly low cutoff in the original excised model. Additionally, the distribution of central L-values is ‘choppier’ than the distribution of characteristic polynomials, in the sense that it is a superposition of a series of peaks: the characteristic polynomial distribution is a smooth approximation to this. The excised model did not attempt to incorporate these successive peaks, only the initial cutoff. Here we experiment with including some of the structure of the L-value distribution. The conclusion is that a critical feature of a good model is to associate the correct mass to the first peak of the L-value distribution.

Optimal Timing for Early Excision in a Deep Partial Thickness Porcine Burn Model.

PubMed

Toussaint, Jimmy; Chung, Won Taek; Mc Clain, Steve; Raut, Vivek; Singer, Adam J

Many deep partial thickness burns require more than 3 weeks to heal resulting in disfiguring and dysfunctional scarring. Early excision of the eschar has been shown to improve outcomes in deep burns; however, the optimal timing of the excision remains controversial. We compared wound healing and scarring of deep partial thickness burns that were excised at different time points in a porcine model. Deep partial thickness burns (2.5 by 2.5 cm each) were created on the backs of six anesthetized pigs using a previously validated model. The burns were randomly assigned to excision at days 2, 4, or 7 using an electric dermatome. Full thickness 4-mm punch biopsies were obtained at several time points for determination of re-epithelialization and at day 28 for determination of scar depth. Digital imaging was used to calculate percentage wound contraction at day 28. There were no statistically significant differences in wound re-epithelialization at any of the studied time points. Scar depth and percentage wound contraction were also similar among the wounds excised at 2, 4, and 7 days (4.4 ± 1.1 mm vs 3.9 ± 1.1 mm vs 4.1 ± 1.2 mm and 52.9 ± 17.9% vs 52.6 ± 15.6% vs 52.5 ± 13.8%, respectively). Timing of eschar excision (at 2, 4, or 7 days) does not affect the rates of re-epithelialization and scarring in a deep partial thickness porcine burn model. Timing of eschar excision may not change outcomes if performed within the first 2 to 7 days after injury.

Developmentally-Regulated Excision of the SPβ Prophage Reconstitutes a Gene Required for Spore Envelope Maturation in Bacillus subtilis

PubMed Central

Abe, Kimihiro; Kawano, Yuta; Iwamoto, Keito; Arai, Kenji; Maruyama, Yuki; Eichenberger, Patrick; Sato, Tsutomu

2014-01-01

Temperate phages infect bacteria by injecting their DNA into bacterial cells, where it becomes incorporated into the host genome as a prophage. In the genome of Bacillus subtilis 168, an active prophage, SPβ, is inserted into a polysaccharide synthesis gene, spsM. Here, we show that a rearrangement occurs during sporulation to reconstitute a functional composite spsM gene by precise excision of SPβ from the chromosome. SPβ excision requires a putative site-specific recombinase, SprA, and an accessory protein, SprB. A minimized SPβ, where all the SPβ genes were deleted, except sprA and sprB, retained the SPβ excision activity during sporulation, demonstrating that sprA and sprB are necessary and sufficient for the excision. While expression of sprA was observed during vegetative growth, sprB was induced during sporulation and upon mitomycin C treatment, which triggers the phage lytic cycle. We also demonstrated that overexpression of sprB (but not of sprA) resulted in SPβ prophage excision without triggering the lytic cycle. These results suggest that sprB is the factor that controls the timing of phage excision. Furthermore, we provide evidence that spsM is essential for the addition of polysaccharides to the spore envelope. The presence of polysaccharides on the spore surface renders the spore hydrophilic in water. This property may be beneficial in allowing spores to disperse in natural environments via water flow. A similar rearrangement occurs in Bacillus amyloliquefaciens FZB42, where a SPβ-like element is excised during sporulation to reconstitute a polysaccharide synthesis gene, suggesting that this type of gene rearrangement is common in spore-forming bacteria because it can be spread by phage infection. PMID:25299644

The specialty of the treating physician affects the likelihood of tumor-free resection margins for basal cell carcinoma: results from a multi-institutional retrospective study.

PubMed

Fleischer, A B; Feldman, S R; Barlow, J O; Zheng, B; Hahn, H B; Chuang, T Y; Draft, K S; Golitz, L E; Wu, E; Katz, A S; Maize, J C; Knapp, T; Leshin, B

2001-02-01

Basal cell carcinoma (BCC) is the most common cutaneous malignancy. Surgical experience and physician specialty may affect the outcome quality of surgical excision of BCC. We performed a multicenter retrospective study of BCC excisions submitted to the respective Departments of Pathology at 4 major university medical centers. Our outcome measure was presence of histologic evidence of tumor present in surgical margins of excision specimens (incomplete excision). Clinician experience was defined as the number of excisions that a clinician performed during the study interval. The analytic sample pool included 1459 tumors that met all inclusion and exclusion criteria. Analyses included univariate and multivariate techniques involving the entire sample and separate subsample analyses that excluded 2 outlying dermatologists. Tumor was present at the surgical margins in 243 (16.6%) of 1459 specimens. A patient's sex, age, and tumor size were not significantly related to the presence of tumor in the surgical margin. Physician experience did not demonstrate a significant difference either in the entire sample (P <.09) or in the subsample analysis (P >.30). Tumors of the head and neck were more likely to be incompletely excised than truncal tumors in all the analyses (P <.03). Compared with dermatologists, otolaryngologists (P <.02) and plastic surgeons (P <.008) were more likely to incompletely excise tumors; however, subsample analysis for plastic surgeons found only a trend toward significance (P <.10). Dermatologists and general surgeons did not differ in the likelihood of performing an incomplete excision (P >.4). The physician specialty may affect the quality of care in the surgical management of BCC.

Intractable epilepsy and structural lesions of the brain: mapping, resection strategies, and seizure outcome.

PubMed

Awad, I A; Rosenfeld, J; Ahl, J; Hahn, J F; Lüders, H

1991-01-01

Forty-seven patients with structural brain lesions on neuroimaging studies and partial epilepsy intractable to medical therapy were studied. Prolonged noninvasive interictal and ictal EEG recording was performed, followed by more focused mapping using chronically implanted subdural electrode plates. Surgical procedures included lesion biopsy, maximal lesion excision, and/or resection of zones of epileptogenesis depending on accessibility and involvement of speech or other functional areas. The epileptogenic zone involved exclusively the region adjacent to the structural lesion in 11 patients. It extended beyond the lesion in 18 patients. Eighteen other patients had remote noncontiguous zones of epileptogenesis. Postoperative control of epilepsy was accomplished in 17 of 18 patients (94%) with complete lesion excision regardless of extent of seizure focus excision. Postoperative control of epilepsy was accomplished in 5 of 6 patients (83%) with incomplete lesion excision but complete seizure focus excision and in 12 of 23 patients (52%) with incomplete lesion excision and incomplete focus excision. The extent of lesion resection was strongly associated with surgical outcome either in itself (p less than 0.003), or in combination with focus excision. Focus resection was marginally associated with surgical outcome as a dichotomous variable (p = 0.048) and showed a trend toward significance (p = 0.07) only as a three-level outcome variable. We conclude that structural lesions are associated with zones of epileptogenesis in neighboring and remote areas of the brain. Maximum resection of the lesion offers the best chance at controlling intractable epilepsy; however, seizure control is achieved in many patients by carefully planned subtotal resection of lesions or foci.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of excise tax increases on cigarette prices in South Africa.

PubMed

Linegar, Daniel J; van Walbeek, Corne

2018-01-01

The effectiveness of excise tax increases as a tool for reducing tobacco consumption depends largely on how the tax increases impact the retail price. We estimate this relationship in South Africa for 2001-2015. Statistics South Africa provided disaggregated cigarette price data, used in the calculation of the Consumers' Price Index. Data on the excise tax per cigarette were obtained from Budget Reviews prepared by the National Treasury of South Africa. Regression equations were estimated for each month. The month-on-month change in cigarette prices in February through April was regressed against March's excise tax change to estimate the pass-through coefficient. For the other 9 months, the month-on-month change in cigarette price was regressed against monthly dummy variables to determine the size of the non-tax-related price increase in each of these months. The analysis was performed in both nominal and real (inflation-adjusted) terms. Expressed in real terms, the excise tax was undershifted. A R1.00 (one rand) increase in the excise tax is associated with an increase in the retail price of cigarettes of R0.90 in the pre-2010 period, and R0.49 in the post-2010 period. In the pre-2010 period, the tobacco industry increased the retail price of cigarettes in July/August, independent of the excise tax increase. The discretionary July/August price increases largely disappeared after 2010, primarily because the market became more competitive. The degree of excise tax pass-through, and the magnitude of discretionary increases in cigarette prices, is significantly determined by the competitive environment in the cigarette market. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Should we excise? Are there any clinical or histologic features that predict upgrade in papillomas, incidental or non-incidental?

PubMed

Zaleski, Michael; Chen, Yun An; Chetlen, Alison L; Mack, Julie; Xu, Liyan; Dodge, Daleela G; Karamchandani, Dipti M

2018-05-11

The clinical decision to excise intraductal papilloma (IDP) without atypia diagnosed on biopsy remains controversial. We sought to establish clinical and histologic predictors (if any) which may predict upgrade in IDP. 296 biopsies (in 278 women) with histologic diagnosis of IDP without atypia were retrospectively identified and placed into Incidental (no corresponding imaging correlate), or Non-incidental (positive imaging correlate) groups. 253/296 (85.5%) cases were non-incidental, and 43/296 (14.5%) were incidental. 73.1% (185/253) non-incidental and 48.8% (21/43) incidental cases underwent excision. 12.4% (23/185) non-incidental cases underwent an upgrade to cancer or high-risk lesion; namely 8-Ductal carcinoma in situ (DCIS), 8-atypical ductal hyperplasia (ADH), 6-lobular neoplasia, and 1-flat epithelial atypia. There was no histopathologic feature on the biopsy in the non-incidental group which predicted upgrade; however a past history of atypia was significantly associated with upgrade. 2 of the 21 incidental cases upgraded (1 to ADH and 1 to lobular neoplasia); the former had a past history of ADH. Both incidental upgrades were >1 mm in size, and were not completely excised on the biopsy. None of the incidental cases which appeared completely excised on biopsy upgraded, irrespective of the size on biopsy. These findings suggest that all non-incidental IDPs should be considered candidates for surgical excision, given the 12.4% upgrade rate and no definitive histologic predictors of upgrade. Patients with incidental IDPs (if <1 mm, completely excised on biopsy and with no history of high risk breast lesion) can be spared excision. Copyright © 2018 Elsevier Inc. All rights reserved.

Technique for laparoscopic autonomic nerve preserving total mesorectal excision.

PubMed

Breukink, S O; Pierie, J P E N; Hoff, C; Wiggers, T; Meijerink, W J H J

2006-05-01

With the introduction of total mesorectal excision (TME) for treatment of rectal cancer, the prognosis of patients with rectal cancer is improved. With this better prognosis, there is a growing awareness about the quality of life of patients after rectal carcinoma. Laparoscopic total mesorectal excision (LTME) for rectal cancer offers several advantages in comparison with open total mesorectal excision (OTME), including greater patient comfort and an earlier return to daily activities while preserving the oncologic radicality of the procedure. Moreover, laparoscopy allows good exposure of the pelvic cavity because of magnification and good illumination. The laparoscope seems to facilitate pelvic dissection including identification and preservation of critical structures such as the autonomic nervous system. The technique for laparoscopic autonomic nerve preserving total mesorectal excision is reported. A three- or four-port technique is used. Vascular ligation, sharp mesorectal dissection and identification and preservation of the autonomic pelvic nerves are described.

Critical concepts and important anatomic landmarks encountered during transanal total mesorectal excision (taTME): toward the mastery of a new operation for rectal cancer surgery.

PubMed

Atallah, S; Albert, M; Monson, J R T

2016-07-01

Over the past 3 years, colorectal surgeons have begun to adapt the technique of transanal total mesorectal excision. As international experience has been quickly forged, an improved recognition of the pitfalls and the practical details of this disruptive technique have been realized. The purpose of this technical note was to express the various nuances of transanal total mesorectal excision as learned during the course of its clinical application and international teaching, so as to rapidly communicate and share important insights with other surgeons who are in the early adoption phase of this approach. The technical points specific to transanal total mesorectal excision are addressed herein. When correctly applied, these will likely improve the quality of surgery and decrease morbidity attributable to inexperience with the transanal approach to total mesorectal excision.

Expression and the Peculiar Enzymatic Behavior of the Trypanosoma cruzi NTH1 DNA Glycosylase

PubMed Central

Ormeño, Fernando; Barrientos, Camila; Ramirez, Santiago; Ponce, Iván; Valenzuela, Lucía; Sepúlveda, Sofía; Bitar, Mainá; Kemmerling, Ulrike; Machado, Carlos Renato; Cabrera, Gonzalo; Galanti, Norbel

2016-01-01

Trypanosoma cruzi, the etiological agent of Chagas’ disease, presents three cellular forms (trypomastigotes, epimastigotes and amastigotes), all of which are submitted to oxidative species in its hosts. However, T. cruzi is able to resist oxidative stress suggesting a high efficiency of its DNA repair machinery.The Base Excision Repair (BER) pathway is one of the main DNA repair mechanisms in other eukaryotes and in T. cruzi as well. DNA glycosylases are enzymes involved in the recognition of oxidative DNA damage and in the removal of oxidized bases, constituting the first step of the BER pathway. Here, we describe the presence and activity of TcNTH1, a nuclear T. cruzi DNA glycosylase. Surprisingly, purified recombinant TcNTH1 does not remove the thymine glycol base, but catalyzes the cleavage of a probe showing an AP site. The same activity was found in epimastigote and trypomastigote homogenates suggesting that the BER pathway is not involved in thymine glycol DNA repair. TcNTH1 DNA-binding properties assayed in silico are in agreement with the absence of a thymine glycol removing function of that parasite enzyme. Over expression of TcNTH1 decrease parasite viability when transfected epimastigotes are submitted to a sustained production of H2O2.Therefore, TcNTH1 is the only known NTH1 orthologous unable to eliminate thymine glycol derivatives but that recognizes and cuts an AP site, most probably by a beta-elimination mechanism. We cannot discard that TcNTH1 presents DNA glycosylase activity on other DNA base lesions. Accordingly, a different DNA repair mechanism should be expected leading to eliminate thymine glycol from oxidized parasite DNA. Furthermore, TcNTH1 may play a role in the AP site recognition and processing. PMID:27284968

Frequency and characteristics of melanomas missed at a pigmented lesion clinic: a registry-based study.

PubMed

Carli, Paolo; Nardini, Paolo; Crocetti, Emanuele; De Giorgi, Vincenzo; Giannotti, Benvenuto

2004-10-01

To ensure the removal of all melanomas at an early phase, a number of benign lesions are currently excised for diagnostic evaluation. Nevertheless, little is known about the frequency of melanomas missed (neither recognized nor excised for diagnostic verification) by early detection practices. This study aimed to investigate the diagnostic performance of a specialized pigmented lesion clinic (PLC) through linkage with a local cancer registry. In 1997, 1741 individuals resident in the area of Florence and Prato, Italy, the catchment area of the Tuscany Cancer Registry (RTT), were consecutively examined at a specialized PLC that has been running since 1992 at the Department of Dermatology of Florence. The outcomes of dermatological consultations retrieved from PLC case notes were compared with all the diagnoses of both in situ and invasive melanoma recorded by the RTT until 31 December 1999. The performance of the PLC in detecting cutaneous melanoma was evaluated in terms of sensitivity, specificity and predictive values, with the RTT data as the gold standard. In the population examined at the PLC, 15 newly incident melanomas, all histologically demonstrated, were recorded by the RTT. In 13 of the 15 cases, excision of the lesion had been recommended by PLC staff, while two melanomas, one in situ and one level II 0.60 mm thick invasive, were missed and were subsequently excised 586 and 824 days, respectively, after the first PLC examination. The clinical and dermoscopic features of the invasive lesion were in agreement with a 'featureless' melanoma, and lacked the well-established parameters of malignancy. A total of 67 benign pigmented skin lesions were excised for diagnostic evaluation. Thus the PLC showed a sensitivity in detecting cutaneous melanoma of 86.7% (95% confidence interval [CI] 85.1-88.3%), a specificity of 95.4% (95% CI 94.3-96.3%), a positive predictive value of 13.7% (95% CI 12.1-15.3%) and a negative predictive value of 99.9% (95% CI 99.7-100.0%). The ratio of melanomas to benign skin lesions excised was 1:5.1. In conclusion, specialized examination of pigmented skin lesions at the PLC offered good level of diagnostic performance, with an acceptable cost in terms of benign lesions removed and overall a low risk of missing melanomas.

29 CFR 779.245 - Conditions for coverage of retail or service enterprises.

Code of Federal Regulations, 2010 CFR

2010-07-01

... annual gross volume of sales made or business done, exclusive of excise taxes at the retail level which... annual gross volume of sales made or business done of at least $250,000, exclusive of excise taxes at the... volume of sales of $1 million or more, exclusive of excise taxes at the retail level which are separately...

26 CFR 54.4975-14 - Election to pay an excise tax for certain pre-1975 prohibited transactions.

Code of Federal Regulations, 2010 CFR

2010-04-01

...-14 Election to pay an excise tax for certain pre-1975 prohibited transactions. (a) In general... the district director to extend the time within which the election is permitted. (d) Computation of... 26 Internal Revenue 17 2010-04-01 2010-04-01 false Election to pay an excise tax for certain pre...

A Novel Esthetic Approach using Connective Tissue Graft for Soft Tissue Defect Following Surgical Excision of Gingival Fibrolipoma

PubMed Central

Parthasarathy, Harinath; Kumar, Praveenkrishna; Gajendran, Priyalochana; Appukuttan, Devapriya

2014-01-01

The aim of the present case report is to evaluate the adjunctive use of a connective tissue graft to overcome soft tissue defects following excision of a gingival fibrolipoma in the aesthetic region. Connective tissue graft has been well documented for treating defects of esthetic concern. However, the literature does not contain many reports on the esthetic clinical outcome following the use of connective tissue graft secondary to excision of soft tissue tumours. A 28-year-old male patient reported with a complaint of a recurrent growth in relation to his lower front tooth region. The lesion which was provisionally diagnosed as fibroma was treated with a complete surgical excision, following which a modified coronally advanced flap and connective tissue graft was adopted to overcome the soft tissue defect. The excised growth was diagnosed histologically as fibrolipoma. One year follow up showed no recurrence of the lesion and good esthetics.The adjunctive use of the connective tissue graft and modified coronally advanced flap predictably yields optimal soft tissue fill and excellent esthetics. Hence, routine use of this procedure may be recommended for surgical excision of soft tissue growths in esthetically sensitive areas. PMID:25584336

Developmentally programmed DNA splicing in Paramecium reveals short-distance crosstalk between DNA cleavage sites

PubMed Central

Gratias, Ariane; Lepère, Gersende; Garnier, Olivier; Rosa, Sarah; Duharcourt, Sandra; Malinsky, Sophie; Meyer, Eric; Bétermier, Mireille

2008-01-01

Somatic genome assembly in the ciliate Paramecium involves the precise excision of thousands of short internal eliminated sequences (IESs) that are scattered throughout the germline genome and often interrupt open reading frames. Excision is initiated by double-strand breaks centered on the TA dinucleotides that are conserved at each IES boundary, but the factors that drive cleavage site recognition remain unknown. A degenerate consensus was identified previously at IES ends and genetic analyses confirmed the participation of their nucleotide sequence in efficient excision. Even for wild-type IESs, however, variant excision patterns (excised or nonexcised) may be inherited maternally through sexual events, in a homology-dependent manner. We show here that this maternal epigenetic control interferes with the targeting of DNA breaks at IES ends. Furthermore, we demonstrate that a mutation in the TA at one end of an IES impairs DNA cleavage not only at the mutant end but also at the wild-type end. We conclude that crosstalk between both ends takes place prior to their cleavage and propose that the ability of an IES to adopt an excision-prone conformation depends on the combination of its nucleotide sequence and of additional determinants. PMID:18420657

Tobacco excise and declining tobacco consumption: the case of Papua New Guinea.

PubMed Central

Chapman, S; Richardson, J

1990-01-01

Excise elasticities of demand for non-cigarette tobacco and cigarettes were calculated for Papua New Guinea for the 14 years 1973-86. Respectively, these were -0.50 and -0.71. This means that 10 percent increases in cigarette and non-cigarette tobacco excise are associated with an estimated 7.1 percent fall in demand for cigarettes and a 5 percent decrease in the demand for tobacco. As tax (excise) elasticities would normally be significantly smaller than price elasticities, these results imply that the consumption of cigarettes and tobacco in Papua New Guinea are more responsive to prices than in the United States and other Western countries. The level of excise is therefore an important and practical instrument for the control of consumption. These elasticities appear to be the first reported for a developing country. It is suggested that if they are indicative of consumer behavior in lower income countries then increasing tobacco and cigarette excise should be considered as an important strategy for the control of smoking in these countries which, because of their large populations, are huge markets for tobacco products and thus major targets for tobacco control measures. PMID:2327528

DNA bending and a flip-out mechanism for base excision by the helix–hairpin–helix DNA glycosylase, Escherichia coli AlkA

PubMed Central

Hollis, Thomas; Ichikawa, Yoshitaka; Ellenberger, Tom

2000-01-01

The Escherichia coli AlkA protein is a base excision repair glycosylase that removes a variety of alkylated bases from DNA. The 2.5 Å crystal structure of AlkA complexed to DNA shows a large distortion in the bound DNA. The enzyme flips a 1–azaribose abasic nucleotide out of DNA and induces a 66° bend in the DNA with a marked widening of the minor groove. The position of the 1–azaribose in the enzyme active site suggests an SN1-type mechanism for the glycosylase reaction, in which the essential catalytic Asp238 provides direct assistance for base removal. Catalytic selectivity might result from the enhanced stacking of positively charged, alkylated bases against the aromatic side chain of Trp272 in conjunction with the relative ease of cleaving the weakened glycosylic bond of these modified nucleotides. The structure of the AlkA–DNA complex offers the first glimpse of a helix–hairpin–helix (HhH) glycosylase complexed to DNA. Modeling studies suggest that other HhH glycosylases can bind to DNA in a similar manner. PMID:10675345

Alternative Fuels Data Center

Science.gov Websites

rate of $0.32 per gasoline gallon equivalent, measured at 5.66 lbs. or 126.67 cubic feet at a base also subject to the excise tax rate of $0.349 per diesel gallon equivalent, measured at 6.06 lbs

[Multivisceral organ procurement for transplantation derived mobilization maneouvres: very helpful auxiliary techniques in the excision of large retroperitoneal masses].

PubMed

González, Javier; Shirodkar, S P; Ciancio, G

2011-04-01

The excision of large retroperitoneal masses poses a challenge for every surgeon. Sometimes the urologist must face situations that do not fit to any conventional approach or technique previously described. Obtaining adequate exposure for safe and oncologically correct management of these masses is based, on many cases, in the mobilization of anatomical adjacent structures to generate a sufficient field in abdominal areas of difficult access. Complex visceral mobilization maneuvers derived from multivisceral transplantation organ procurement surgery provides ancillary techniques that used properly facilitate their successful resolution. The main purpose of this paper is the description of these surgical maneuvers essential to increase both exposure and vascular control in addressing the ever-dreaded high-volume retroperitoneal masses.

Society of Behavioral Medicine (SBM) position statement: Enact taxes on sugar sweetened beverages to prevent chronic disease.

PubMed

Taber, Daniel R; Dulin-Keita, Akilah; Fallon, Megan; Chaloupka, Frank J; Andreyeva, Tatiana; Schwartz, Marlene B; Harris, Jennifer L

2018-04-10

The Society of Behavioral Medicine (SBM) encourages stakeholders to implement a sugar sweetened beverage excise tax. Sugar sweetened beverages are the largest source of added sugars in the USA and have detrimental effects on population health by increasing risks for chronic diseases. Based on existing research evidence, SBM supports an excise tax equivalent to at least 20% to meaningfully affect consumption patterns. As evidenced by research studies in Mexico and the USA, sugar sweetened beverage taxes can have positive impacts on population health and can raise significant tax revenue. To avoid potential unintended consequences that may arise from taxes to improve diet-related behaviors, it is important to monitor industry and consumer behavior in response to the tax.

Vectorology and Factor Delivery in Induced Pluripotent Stem Cell Reprogramming

PubMed Central

2014-01-01

Induced pluripotent stem cell (iPSC) reprogramming requires sustained expression of multiple reprogramming factors for a limited period of time (10–30 days). Conventional iPSC reprogramming was achieved using lentiviral or simple retroviral vectors. Retroviral reprogramming has flaws of insertional mutagenesis, uncontrolled silencing, residual expression and re-activation of transgenes, and immunogenicity. To overcome these issues, various technologies were explored, including adenoviral vectors, protein transduction, RNA transfection, minicircle DNA, excisable PiggyBac (PB) transposon, Cre-lox excision system, negative-sense RNA replicon, positive-sense RNA replicon, Epstein-Barr virus-based episomal plasmids, and repeated transfections of plasmids. This review provides summaries of the main vectorologies and factor delivery systems used in current reprogramming protocols. PMID:24625220

Comparing projected impacts of cigarette floor price and excise tax policies on socioeconomic disparities in smoking

PubMed Central

Golden, Shelley D; Farrelly, Matthew C; Luke, Douglas A; Ribisl, Kurt M

2016-01-01

Background About half of all US states have cigarette minimum price laws (MPLs) that require a per cent mark-up on prices, but research suggests they may not be very effective in raising prices. An alternative type of MPL sets a floor price below which packs cannot be sold, and may be more promising. This new type of MPL policy has only been implemented in 1 city, therefore its benefits relative to excise taxes is difficult to assess. Methods We constructed a set of possible state floor price MPL options, and matched them to possible state excise tax hikes designed to produce similar average price increases. Using self-reported price and cigarette consumption data from 23 521 participants in the 2010–2011 Tobacco Use Supplement of the Current Population Survey, we projected changes in pack prices and cigarette consumption following implementation of each paired MPL and tax option, for lower and higher income groups. Results We project that state MPLs set at the average reported pack price would raise prices by $0.33 and reduce cigarette consumption by about 4%; a tax with a similar average price effect would reduce consumption by 2.3%. MPLs and taxes that raise average prices by more than $2.00 would reduce consumption by 15.9% and 13.5%, respectively. In all models, we project that MPLs will reduce income-based smoking disparities more than their comparable excise taxes. Conclusions Floor price cigarette MPLs set at or above what consumers currently report paying could reduce both tobacco use and socioeconomic disparities in smoking. PMID:27697949

Ultrasound-guided core biopsy in the diagnosis of lymphoma of the head and neck. A 9 year experience

PubMed Central

Burke, C; Thomas, R; Inglis, C; Baldwin, A; Ramesar, K; Grace, R; Howlett, D C

2011-01-01

Objectives This retrospective study aimed to evaluate the diagnostic utility of ultrasound-guided core biopsy (USCB) in lymphoma of the head and neck, in particular whether core biopsy can provide sufficient diagnostic information for definitive treatment. Methods All lymphomas diagnosed in the head and neck at Eastbourne General Hospital between January 2000 and June 2009 were identified. Radiology and pathology reports were reviewed and the diagnostic techniques recorded. The type of biopsy (fine needle aspiration, needle core, surgical excision biopsy) used to establish a diagnosis sufficient to allow treatment, i.e. the "index" diagnostic technique, was identified. Previous inconclusive or inadequate biopsies were noted. Pathology reports based on USCB were graded 0–3 according to diagnostic completeness and ability to provide treatment information. Results Of 691 overall cases of lymphoma diagnosed over the 9 year period, 171 different patients presented with lymphoma in the head and neck. Of these 171, 83 had USCB biopsy during diagnostic work up. 60 were regarded as grade 3 where a confident diagnosis of lymphoma was made. In seven patients, clinical management proceeded on the basis of a suggestive (grade 2) pathology report without surgical excision, and these were therefore also included as "index" biopsies. Overall therefore, 67/83 core biopsies (81%) provided adequate information to allow treatment. Surgical excision biopsy was the index modality in 104 cases. Conclusion In the majority of cases USCB is adequate for confident histopathological diagnosis avoiding the need for surgical excision biopsy in cases of suspected head and neck lymphoma. PMID:21427181

Bench model surgical skill training improves novice ability to multitask: a randomized controlled study.

PubMed

Grierson, Lawrence; Melnyk, Megan; Jowlett, Nathan; Backstein, David; Dubrowski, Adam

2011-01-01

Skills training in simulation laboratories is becoming increasingly common. However, the educational benefit of these laboratories remains unclear. This study examined whether such training enables better performance on the simultaneous execution of technical skill and knowledge retention. Twenty-four novice trainees completed the elliptical excision on baseline testing. Following baseline testing twelve of the novices completed a technical practice (simulation training group) session, while the other twelve did not (control group). One week later, all participants returned for dual-task follow up testing in which they performed the excision while listening to a didactic lesson on the staging and treatment of cutaneous melanoma. The dual-tasking during the post test was standardized, whereby excision sutures 3 and 5 were performed alone (single), and sutures 4 and 6 were performed concurrently with the didactic lecture (dual). Seven additional trainees also participated as controls that were randomized to listen to the didactic lesson alone (knowledge retention alone group). Knowledge retention was assessed by a multiple choice questionnaire (MCQ). Technical performance was evaluated with computer and expert-based measures. Time to complete the performance improved among both groups completing the elliptical excision on follow-up testing (p<0.01). The simulation training group demonstrated superior hand motion performance on simultaneous didactic lesson testing (p<0.01). Novices from the no-training group performed statistically worse while suturing concurrently with the didactic lesson (p<0.01). The pretraining of novices in surgical skills laboratories leads to improved technical performance during periods of increased attention demands.

Mammotome-Assisted Liposuction: A Novel Technique for Accessory Breasts.

PubMed

Tang, Xin

2017-06-01

Due to its minimally invasive and highly precise nature, the mammotome, a vacuum-assisted breast biopsy device, has proven effective for the treatment of benign breast lesions. Taking advantage of both liposuction and the mammotome, we utilized the mammotome device for the excision of accessory breasts. Between July 2010 and June 2014, 16 patients with accessory breasts received mammotome-assisted liposuction. After adipose was removed using this procedure, the mammotome system was used to excise the fibro-glandular tissue in accessory breasts under ultrasound monitoring. All patients were satisfied with their appearance after surgery. A single 5-mm incision, which was well hidden in the axillary skin folds and allowed for restoration, provided an aesthetically pleasing contour to the axilla. Mammotome-assisted liposuction is a new approach that can be used to excise both adipose and fibro-glandular breast tissue simultaneously with a minimal incision, and provides a favorable contour to the axilla. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Immunosuppression and temporary skin transplantation in the treatment of massive third degree burns.

PubMed Central

Burke, J F; Quinby, W C; Bondoc, C C; Cosimi, A B; Russell, P S; Szyfelbein, S K

1975-01-01

A method of burn treatment (immunosuppression and temporary skin transplantation) for patients suffering from massive third degree burns is evaluated. The method is based on the prompt excision of all dead tissue (burn eschar) and immediate closure of the wound by skin grafts. Total wound closure is achieved before bacterial infection or organ failure takes place by carrying out all initial excision and grafting procedures within the first ten days post burn and supplementing the limited amount of autograft with allograft. Continuous wound closure is maintained for up to 50 days through immunosuppression. Both azathioprine and ATG have been used but ATG is preferred. During the period of immunosuppression, allograft is stepwise excised and replaced with autograft donor sites regenerate for recropping. Bacterial complications are minimized by housing the patient in the protected environment of the Bacteria Controlled Nursing Unit. Intensive protein and calorie alimentation are provided, and 0.5% aqueous AgNO3 dressings are used. A swinging febrile illness has been associated with large areas of allograft rejection. Eleven children have been treated and seven have been returned to normal, productive schooling. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. PMID:809014

Carbon dioxide (CO2) laser third eyelid excision: surgical description and report of 7 cases.

PubMed

Dees, Dustin D; Knollinger, Amy M; MacLaren, Nicole E

2015-09-01

To describe a novel technique for third eyelid (TEL) excision using a carbon dioxide (CO2) laser. Prospective. The procedure was performed on six canine patients and one feline patient. The laser was set to 6 Watts (W) of power and a linear continuous setting. Forceps were used to elevate the TEL and, with a protective shield covering the cornea, the base was cut and cauterized simultaneously. Minimal to no hemorrhage was observed, and the conjunctiva was left to heal by second intention. Seven patients underwent unilateral surgical TEL excision. All patients had suspected neoplasms affecting either the glandular tissues or conjunctival surfaces of the TEL. Clean surgical margins were achieved in all but one patient. All surgical sites were considered healed by 14 days showing mild-to-moderate conjunctival hyperemia and accumulation of mucoid discharge at the ventronasal fornix. One patient experienced postoperative keratoconjunctivitis sicca. Prolapse of orbital fat was not observed in any patient. Use of CO2 laser appears to be an efficient and effective means for surgical third eyelid removal with excellent postoperative comfort and minimal complications. © 2014 American College of Veterinary Ophthalmologists.

[Arthroscopic excision of elastofibroma dorsi at scapulothoracic joint: a surgical technique].

PubMed

Çakmak, Gökhan; Ergün, Tarkan; Şahin, M Şükrü

2014-01-01

Elastofibroma dorsi is a rare soft tissue pseudotumor which is located at the anteroinferior aspect of the scapula. In this article, we report a 19-year-old female case who had arthroscopic marginal excision of elastofibroma dorsi at the scapulothoracic joint without recurrences during follow-up. The arthroscopic marginal excision of the elastofibroma dorsi may have good clinical results in selected cases.

Crystal structures of 3-methyladenine DNA glycosylase MagIII and the recognition of alkylated bases

PubMed Central

Eichman, Brandt F.; O’Rourke, Eyleen J.; Radicella, J.Pablo; Ellenberger, Tom

2003-01-01

DNA glycosylases catalyze the excision of chemically modified bases from DNA. Although most glycosylases are specific to a particular base, the 3-methyladenine (m3A) DNA glycosylases include both highly specific enzymes acting on a single modified base, and enzymes with broader specificity for alkylation-damaged DNA. Our structural understanding of these different enzymatic specificities is currently limited to crystal and NMR structures of the unliganded enzymes and complexes with abasic DNA inhibitors. Presented here are high-resolution crystal structures of the m3A DNA glycosylase from Helicobacter pylori (MagIII) in the unliganded form and bound to alkylated bases 3,9-dimethyladenine and 1,N6-ethenoadenine. These are the first structures of a nucleobase bound in the active site of a m3A glycosylase belonging to the helix–hairpin–helix superfamily. MagIII achieves its specificity for positively-charged m3A not by direct interactions with purine or methyl substituent atoms, but rather by stacking the base between two aromatic side chains in a pocket that excludes 7-methylguanine. We report base excision and DNA binding activities of MagIII active site mutants, together with a structural comparison of the HhH glycosylases. PMID:14517230

Surface-functionalized polymethacrylic acid based hydrogel microparticles for oral drug delivery.

PubMed

Sajeesh, S; Bouchemal, K; Sharma, C P; Vauthier, C

2010-02-01

Aim of the present work was to develop novel thiol-functionalized hydrogel microparticles based on poly(methacrylic acid)-chitosan-poly(ethylene glycol) (PCP) for oral drug delivery applications. PCP microparticles were prepared by a modified ionic gelation process in aqueous medium. Thiol modification of surface carboxylic acid groups of PCP micro particles was carried out by coupling l-cysteine with a water-soluble carbodiimide. Ellman's method was adopted to quantify the sulfhydryl groups, and dynamic light-scattering technique was used to measure the average particle size. Cytotoxicity of the modified particles was evaluated on Caco 2 cells by MTT assay. Effect of thiol modification on permeability of paracellular marker fluorescence dextran (FD4) was evaluated on Caco 2 cell monolayers and freshly excised rat intestinal tissue with an Ussing chamber set-up. Mucoadhesion experiments were carried out by an ex vivo bioadhesion method with excised rat intestinal tissue. The average size of the PCP microparticles was increased after thiol modification. Thiolated microparticles significantly improved the paracellular permeability of FD4 across Caco 2 cell monolayers, with no sign of toxicity. However, the efficacy of thiolated system remained low when permeation experiments were carried out across excised intestinal membrane. This was attributed to the high adhesion of the thiolated particles on the gut mucosa. Nevertheless, it can be concluded that surface thiolation is an interesting strategy to improve paracellular permeability of hydrophilic macromolecules. Copyright (c) 2009 Elsevier B.V. All rights reserved.

DIFFERENTIAL ROLE OF BASE EXCISION REPAIR PROTEINS IN MEDIATING CISPLATIN CYTOTOXICITY

PubMed Central

Sawant, Akshada; Floyd, Ashley M.; Dangeti, Mohan; Lei, Wen; Sobol, Robert W.; Patrick, Steve M.

2017-01-01

Interstrand crosslinks (ICLs) are covalent lesions formed by cisplatin. The mechanism for the processing and removal of ICLs by DNA repair proteins involves nucleotide excision repair (NER), homologous recombination (HR) and fanconi anemia (FA) pathways. In this report, we monitored the processing of a flanking uracil adjacent to a cisplatin ICL by the proteins involved in the base excision repair (BER) pathway. Using a combination of extracts, purified proteins, inhibitors, functional assays and cell culture studies, we determined the specific BER proteins required for processing a DNA substrate with a uracil adjacent to a cisplatin ICL. Uracil DNA glycosylase (UNG) is the primary glycosylase responsible for the removal of uracils adjacent to cisplatin ICLs, whereas other uracil glycosylases can process uracils in the context of undamaged DNA. Repair of the uracil adjacent to cisplatin ICLs proceeds through the classical BER pathway, highlighting the importance of specific proteins in this redundant pathway. Removal of uracil is followed by the generation of an abasic site and subsequent cleavage by AP endonuclease 1 (APE1). Inhibition of either the repair or redox domain of APE1 gives rise to cisplatin resistance. Inhibition of the lyase domain of Polymerase β (Polβ) does not influence cisplatin cytotoxicity. In addition, lack of XRCC1 leads to increased DNA damage and results in increased cisplatin cytotoxicity. Our results indicate that BER activation at cisplatin ICLs influences crosslink repair and modulates cisplatin cytotoxicity via specific UNG, APE1 and Polβ polymerase functions. PMID:28110804

Beyond Wires and Seeds: Reflector-guided Breast Lesion Localization and Excision.

PubMed

Mango, Victoria L; Wynn, Ralph T; Feldman, Sheldon; Friedlander, Lauren; Desperito, Elise; Patel, Sejal N; Gomberawalla, Ameer; Ha, Richard

2017-08-01

Purpose To evaluate outcomes of Savi Scout (Cianna Medical, Aliso Viejo, Calif) reflector-guided localization and excision of breast lesions by analyzing reflector placement, localization, and removal, along with target excision and rates of repeat excision (referred to as re-excision). Materials and Methods A single-institution retrospective review of 100 women who underwent breast lesion localization and excision by using the Savi Scout surgical guidance system from June 2015 to May 2016 was performed. By using image guidance 0-8 days before surgery, 123 nonradioactive, infrared-activated, electromagnetic wave reflectors were percutaneously inserted adjacent to or within 111 breast targets. Twenty patients had two or three reflectors placed for bracketing or for localizing multiple lesions, and when ipsilateral, they were placed as close as 2.6 cm apart. Target and reflector were localized intraoperatively by one of two breast surgeons who used a handpiece that emitted infrared light and electromagnetic waves. Radiographs of the specimen and pathologic analysis helped verify target and reflector removal. Target to reflector distance was measured on the mammogram and radiograph of the specimen, and reflector depth was measured on the mammogram. Pathologic analysis was reviewed. Re-excision rates and complications were recorded. By using statistics software, descriptive statistics were generated with 95% confidence intervals (CIs) calculated. Results By using sonographic (40 of 123; 32.5%; 95% CI: 24.9%, 41.2%) or mammographic (83 of 123; 67.5%; 95% CI: 58.8% 75.1%) guidance, 123 (100%; 95% CI: 96.4%, 100%) reflectors were placed. Mean mammographic target to reflector distance was 0.3 cm. All 123 (100%; 95% CI: 96.4%, 100%) targets and reflectors were excised. Pathologic analysis yielded 54 of 110 malignancies (49.1%; 95% CI: 39.9%, 58.3%; average, 1.0 cm; range, 0.1-5 cm), 32 high-risk lesions (29.1%; 95% CI: 21.4%, 38.2%), and 24 benign lesions (21.8%; 95% CI: 115.1%, 30.4%). Four of 54 malignant cases (7.4%; 95% CI: 2.4%, 18.1%) demonstrated margins positive for cancer that required re-excision. Five of 110 radiographs of the specimen (4.5%; 95% CI: 1.7%, 10.4%) demonstrated increased distance between the target and reflector distance of greater than 1.0 cm (range, 1.1-2.6 cm) compared with postprocedure mammogram the day of placement, three of five were associated with hematomas, two of five migrated without identifiable cause. No related postoperative complications were identified. Conclusion Savi Scout is an accurate, reliable method to localize and excise breast lesions with acceptable margin positivity and re-excision rates. Bracketing is possible with reflectors as close as 2.6 cm. Savi Scout overcomes many limitations of other localization methods, which warrants further study. © RSNA, 2017.

Margins in Skin Excision Biopsies: Principles and Guidelines

PubMed Central

Ranjan, Richa; Singh, Lavleen; Arava, Sudheer K; Singh, Manoj Kumar

2014-01-01

Skin biopsies are usually undertaken to confirm a clinical diagnosis, to remove a lesion, and to determine the adequacy of excised tissue margin. A surgical margin is technically defined as the “edge” of the tissue removed. The term is especially pertinent when the tissue excised is suspected of being involved by a malignant process. One of the most important predictive and prognostic factors of a malignant lesion is whether the margins of the resected specimen are involved by the tumor or not. The purpose of this review is to provide an insight into grossing of a skin biopsy specimen with emphasis on techniques and reporting of excision biopsy margins. PMID:25484385

Retinal detachment 7 years after prophylactic schisis cavity excision in juvenile X-linked retinoschisis.

PubMed

Sobrin, Lucia; Berrocal, Audina M; Murray, Timothy G

2003-01-01

A 7-year-old boy with X-linked juvenile retinoschisis developed a retinal detachment at the site of previous prophylactic excision of a schisis cavity. The patient underwent a scleral buckle procedure, pars plana vitrectomy, membrane peel, and silicone oil injection with successful reattachment. At last follow-up, the visual acuity was 20/400 and the retina was attached. Prophylactic excision of a schisis cavity may be complicated by retinal detachment several years after the surgery. Given the favorable natural history of schisis cavities in X-linked juvenile retinoschisis, the decision to perform prophylactic excision should be undertaken cautiously after full consideration of the potential complications.

Orange Peel Excision of Gland: A Novel Surgical Technique for Treatment of Gynecomastia.

PubMed

S S, Shirol

2016-12-01

Gynecomastia is a common aesthetic problem faced by men with reported incidence as high as 65% with serious psychosocial impact. Although various techniques of liposculpture combined with glandular excision is the standard of treatment, many of the glandular excision techniques have inherent limitations and complications such as leaving a long scar, long operative time, contour abnormalities, and increased risk of hematoma. Here, we describe an innovative "the orange peel excision of gland (OPEG) technique" which overcomes these limitations with excellent cosmetic results. A total of 38 breasts were operated in 20 patients (18 bilateral and 2 unilateral). All the patients underwent suction-assisted liposuction and glandular excision under general anesthesia by our OPEG technique. The average operative time per breast was 60 minutes. One patient had a small hematoma which did not require evacuation. The patient satisfaction rate was 95%. The technique has reduced operative time and avoids residual gland and hematoma with excellent aesthetic outcome.

CO2 laser versus cold steel margin analysis following endoscopic excision of glottic cancer

PubMed Central

2014-01-01

Objective To compare the suitability of CO2 laser with steel instruments for margin excision in transoral laser microsurgery. Methods Prospective randomized blinded study. Patients with glottic cancer undergoing laser resection were randomized to margin excision by either steel instruments or CO2 laser. Margins were analyzed for size, interpretability and degree of artifact by a pathologist who was blinded to technique. Results 45 patients were enrolled in the study with 226 total margins taken. 39 margins taken by laser had marked artifact and 0 were uninterpretable. 20 margins taken by steel instruments had marked artifact, and 2 were uninterpretable. Controlling for margin size, the laser technique was associated with increasing degrees of margin artifact (p = 0.210), but there was no difference in crude rates of uninterpretability (p = 0.24). Conclusion Laser margin excision is associated with a greater degree of artifact than steel instrument excision, but was not associated with higher rate of uninterpretability. PMID:24502856

Recurrence case of rare scalp dermatofibrosarcoma protuberans: Two case reports of a wide radical excision, craniectomy bone involvement followed by cranioplasty and reconstruction

PubMed Central

Faried, Ahmad; Hadisaputra, Wargian; Arifin, Muhammad Z.

2017-01-01

Background: Dermatofibrosarcoma protuberans (DFSP) is a rare low-grade sarcoma of the fibroblast originating from the dermal layer of the skin, characterized by a locally aggressive growth and high rate of local recurrence. Case Description: Two patients underwent a wide radical excision of recurrent scalp DFSP which was reconstructed with translational skin flap and split-thickness skin graft. We described above cases several years ago with a local excision of the tumor; recently, they developed local recurrence of DFSP with calvarial involvement. We then performed a wide radical excision, with craniectomy of the cranial defect followed by cranioplasty using titanium mesh, continuing with reconstruction. Conclusion: A successful treatment and management depends on achieving local control and preventing cosmetic and functional deficit; all efforts should be made for complete excision. Postoperative follow-up recommended for highly suspicious cases and annual checkups should be performed up to 5 years after definitive therapy. PMID:28607816

Cigarette Excise Taxes in Context: Cautionary Lessons from the U.S. Experience.

PubMed

Campbell, Richard B; Balbach, Edith D

2015-01-01

Cigarette excise taxes are an important tool in the World Health Organization Framework Convention on Tobacco Control strategy for reducing global tobacco consumption. However, contemporary tobacco control efforts also coincide with the proliferation of neoliberal economic programs calling for the withdrawal of state activity from the economy to facilitate trade. In this environment, cigarette excise taxes may be seen less as an instrument of tobacco control than a feature of an economic program that is punitive to lower-income people. This article reviews collaboration between progressive organizations in the United States and the tobacco industry in the 1980s and 1990s, documenting potential sources of unanticipated resistance to excise taxes and highlighting the tobacco industry's capacity to engage in policy issues through third-party surrogates. It is important for those implementing cigarette excise tax increases to distance tobacco control objectives from larger economic policy measures and for tobacco control advocates to build alliances with organizations working for economic fairness in order to address mutual concerns. © SAGE Publications 2015.

Functional Polymorphisms of Base Excision Repair Genes XRCC1 and APEX1 Predict Risk of Radiation Pneumonitis in Patients With Non-Small Cell Lung Cancer Treated With Definitive Radiation Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yin Ming; Liao Zhongxing; Liu Zhensheng

2011-11-01

Purpose: To explore whether functional single nucleotide polymorphisms (SNPs) of base-excision repair genes are predictors of radiation treatment-related pneumonitis (RP), we investigated associations between functional SNPs of ADPRT, APEX1, and XRCC1 and RP development. Methods and Materials: We genotyped SNPs of ADPRT (rs1136410 [V762A]), XRCC1 (rs1799782 [R194W], rs25489 [R280H], and rs25487 [Q399R]), and APEX1 (rs1130409 [D148E]) in 165 patients with non-small cell lung cancer (NSCLC) who received definitive chemoradiation therapy. Results were assessed by both Logistic and Cox regression models for RP risk. Kaplan-Meier curves were generated for the cumulative RP probability by the genotypes. Results: We found that SNPsmore » of XRCC1 Q399R and APEX1 D148E each had a significant effect on the development of Grade {>=}2 RP (XRCC1: AA vs. GG, adjusted hazard ratio [HR] = 0.48, 95% confidence interval [CI], 0.24-0.97; APEX1: GG vs. TT, adjusted HR = 3.61, 95% CI, 1.64-7.93) in an allele-dose response manner (Trend tests: p = 0.040 and 0.001, respectively). The number of the combined protective XRCC1 A and APEX1 T alleles (from 0 to 4) also showed a significant trend of predicting RP risk (p = 0.001). Conclusions: SNPs of the base-excision repair genes may be biomarkers for susceptibility to RP. Larger prospective studies are needed to validate our findings.« less

Heat shock protein 70 stimulation of the deoxyribonucleic acid base excision repair enzyme polymerase β

PubMed Central

Mendez, Frances; Kozin, Elliott; Bases, Robert

2003-01-01

Base excision repair (BER) of damaged deoxyribonucleic acid (DNA) is a multistep process during which potentially lethal abasic sites temporarily exist. Repair of these lesions is greatly stimulated by heat shock protein 70 (Hsp70), which enhances strand incision and removal of the abasic sites by human apurinic-apyrimidinic endonuclease (HAP1). The resulting single-strand gaps must then be filled in. Here, we show that Hsp70 and its 48- and 43-kDa N-terminal domains greatly stimulated filling in the single-strand gaps by DNA polymerase β, a novel finding that extends the role of Hsps in DNA repair. Incorporation of deoxyguanosine monophosphate (dGMP) to fill in single-strand gaps in DNA phagemid pBKS by DNA polymerase β was stimulated by Hsp70. Truncated proteins derived from the C-terminus of Hsp70 as well as unrelated proteins were less effective, but proteins derived from the N-terminus of Hsp70 remained efficient stimulators of DNA polymerase β repair of DNA single-strand gaps. In agreement with these results, repair of a gap in a 30-bp oligonucleotide by polymerase β also was strongly stimulated by Hsp70 although not by a truncated protein from the C-terminus of Hsp70. Sealing of the repaired site in the oligonucleotide by human DNA ligase 1 was not specifically stimulated by Hsp-related proteins. Results presented here now implicate and extend the role of Hsp70 as a partner in the enzymatic repair of damaged DNA. The participation of Hsp70 jointly with base excision enzymes improves repair efficiency by mechanisms that are not yet understood. PMID:14627201

Roll-your-own cigarettes in Europe: use, weight and implications for fiscal policies.

PubMed

Gallus, Silvano; Lugo, Alessandra; Ghislandi, Simone; La Vecchia, Carlo; Gilmore, Anna B

2014-05-01

Excise duties on roll-your-own (RYO) tobacco, which are generally based on RYO cigarettes containing 1 g of tobacco, are lower than duties on factory-made (FM) cigarettes. This provides a price incentive for smokers to switch to RYO, the use of which is increasing across Europe. To effectively approximate duties on the two types of products, accurate data on the weight of RYO cigarettes are required. We provide updated information on RYO use and RYO cigarette weight across Europe. From a representative face-to-face survey conducted in 2010 in 18 European countries (Albania, Austria, Bulgaria, Czech Republic, Croatia, England, Finland, France, Greece, Hungary, Ireland, Italy, Latvia, Poland, Portugal, Romania, Spain and Sweden), we considered data from 5158 current smokers aged 15 years or above, with available information on daily consumption of FM and RYO cigarettes separately. In Europe, 10.4% of current smokers (12.9% of men and 7.5% of women) were 'predominant' RYO users (i.e. >50% of cigarettes smoked). This proportion was highest in England (27.3%), France (16.5%) and Finland (13.6%). The median weight of one RYO cigarette is 0.75 g (based on 192 smokers consuming exclusively RYO cigarettes). The proportion of RYO smokers is substantial in several European countries. Our finding on the weight of RYO cigarettes is consistent with the scientific literature and industry documents showing that the weight of RYO cigarettes is substantially lower than that of FM ones. Basing excise duties on RYO on an average cigarette weight of 0.75 g rather than 1 g would help increase the excise levels to those on FM cigarettes.

RPA physically interacts with the human DNA glycosylase NEIL1 to regulate excision of oxidative DNA base damage in primer-template structures.

PubMed

Theriot, Corey A; Hegde, Muralidhar L; Hazra, Tapas K; Mitra, Sankar

2010-06-04

The human DNA glycosylase NEIL1, activated during the S-phase, has been shown to excise oxidized base lesions in single-strand DNA substrates. Furthermore, our previous work demonstrating functional interaction of NEIL1 with PCNA and flap endonuclease 1 (FEN1) suggested its involvement in replication-associated repair. Here we show interaction of NEIL1 with replication protein A (RPA), the heterotrimeric single-strand DNA binding protein that is essential for replication and other DNA transactions. The NEIL1 immunocomplex isolated from human cells contains RPA, and its abundance in the complex increases after exposure to oxidative stress. NEIL1 directly interacts with the large subunit of RPA (K(d) approximately 20 nM) via the common interacting interface (residues 312-349) in NEIL1's disordered C-terminal region. RPA inhibits the base excision activity of both wild-type NEIL1 (389 residues) and its C-terminal deletion CDelta78 mutant (lacking the interaction domain) for repairing 5-hydroxyuracil (5-OHU) in a primer-template structure mimicking the DNA replication fork. This inhibition is reduced when the damage is located near the primer-template junction. Contrarily, RPA moderately stimulates wild-type NEIL1 but not the CDelta78 mutant when 5-OHU is located within the duplex region. While NEIL1 is inhibited by both RPA and Escherichia coli single-strand DNA binding protein, only inhibition by RPA is relieved by PCNA. These results showing modulation of NEIL1's activity on single-stranded DNA substrate by RPA and PCNA support NEIL1's involvement in repairing the replicating genome. Copyright 2010 Elsevier B.V. All rights reserved.

The contribution of Nth and Nei DNA glycosylases to mutagenesis in Mycobacterium smegmatis.

PubMed

Moolla, Nabiela; Goosens, Vivianne J; Kana, Bavesh D; Gordhan, Bhavna G

2014-01-01

The increased prevalence of drug resistant strains of Mycobacterium tuberculosis (Mtb) indicates that significant mutagenesis occurs during tuberculosis disease in humans. DNA damage by host-derived reactive oxygen/nitrogen species is hypothesized to be critical for the mutagenic process in Mtb thus, highlighting an important role for DNA repair enzymes in maintenance of genome fidelity. Formamidopyrimidine (Fpg/MutM/Fapy) and EndonucleaseVIII (Nei) constitute the Fpg/Nei family of DNA glycosylases and together with EndonucleaseIII (Nth) are central to the base excision repair pathway in bacteria. In this study we assess the contribution of Nei and Nth DNA repair enzymes in Mycobacterium smegmatis (Msm), which retains a single nth homologue and duplications of the Fpg (fpg1 and fpg2) and Nei (nei1 and nei2) homologues. Using an Escherichia coli nth deletion mutant, we confirm the functionality of the mycobacterial nth gene in the base excision repair pathway. Msm mutants lacking nei1, nei2 and nth individually or in combination did not display aberrant growth in broth culture. Deletion of nth individually results in increased UV-induced mutagenesis and combinatorial deletion with the nei homologues results in reduced survival under oxidative stress conditions and an increase in spontaneous mutagenesis to rifampicin. Deletion of nth together with the fpg homolgues did not result in any growth/survival defects or changes in mutation rate. Furthermore, no differential emergence of the common rifampicin resistance conferring genotypes were noted. Collectively, these data confirm a role for Nth in base excision repair in mycobacteria and further highlight a novel interplay between the Nth and Nei homologues in spontaneous mutagenesis. Copyright © 2013 Elsevier B.V. All rights reserved.

ICE Afe 1, an actively excising genetic element from the biomining bacterium Acidithiobacillus ferrooxidans.

PubMed

Bustamante, Paula; Covarrubias, Paulo C; Levicán, Gloria; Katz, Assaf; Tapia, Pablo; Holmes, David; Quatrini, Raquel; Orellana, Omar

2012-01-01

Integrative conjugative elements (ICEs) are self-transferred mobile genetic elements that contribute to horizontal gene transfer. An ICE (ICEAfe1) was identified in the genome of Acidithiobacillus ferrooxidans ATCC 23270. Excision of the element and expression of relevant genes under normal and DNA-damaging growth conditions was analyzed. Bioinformatic tools and DNA amplification methods were used to identify and to assess the excision and expression of genes related to the mobility of the element. Both basal and mitomycin C-inducible excision as well as expression and induction of the genes for integration/excision are demonstrated, suggesting that ICEAfe1 is an actively excising SOS-regulated mobile genetic element. The presence of a complete set of genes encoding self-transfer functions that are induced in response to DNA damage caused by mitomycin C additionally suggests that this element is capable of conjugative transfer to suitable recipient strains. Transfer of ICEAfe1 may provide selective advantages to other acidophiles in this ecological niche through dissemination of gene clusters expressing transfer RNAs, CRISPRs, and exopolysaccharide biosynthesis enzymes, probably by modification of translation efficiency, resistance to bacteriophage infection and biofilm formation, respectively. These data open novel avenues of research on conjugative transformation of biotechnologically relevant microorganisms recalcitrant to genetic manipulation. Copyright © 2013 S. Karger AG, Basel.

Another heritage from the RNA world: self-excision of intron sequence from nuclear pre-tRNAs.

PubMed

Weber, U; Beier, H; Gross, H J

1996-06-15

The intervening sequences of nuclear tRNA precursors are known to be excised by tRNA splicing endonuclease. We show here that a T7 transcript corresponding to a pre-tRNA(Tyr) from Arabidopsis thaliana has a highly specific activity for autolytic intron excision. Self-cleavage occurs precisely at the authentic 3'-splice site and at the phosphodiester bond one nucleotide downstream of the authentic 5'-splice site. The reaction results in fragments with 2',3'-cyclic phosphate and 5'-OH termini. It is resistant to proteinase K and/or SDS treatment and is not inhibited by added tRNA. The self-cleavage depends on Mg2+ and is stimulated by spermine and Triton X-100. A set of sequence variants at the cleavage sites has been analysed for autolytic intron excision and, in parallel, for enzymatic in vitro splicing in wheat germ S23 extract. Single-stranded loops are a prerequisite for both reactions. Self-cleavage not only occurs at pyrimidine-A but also at U-U bonds. Since intron self-excision is only about five times slower than the enzymatic intron excision in a wheat germ S23 extract, we propose that the splicing endonuclease may function by improving the preciseness and efficiency of an inherent pre-tRNA self-cleavage activity.

Physiological Function of Rac Prophage During Biofilm Formation and Regulation of Rac Excision in Escherichia coli K-12.

PubMed

Liu, Xiaoxiao; Li, Yangmei; Guo, Yunxue; Zeng, Zhenshun; Li, Baiyuan; Wood, Thomas K; Cai, Xingsheng; Wang, Xiaoxue

2015-11-04

Rac or rac-like prophage harbors many genes with important physiological functions, while it remains excision-proficient in several bacterial strains including Escherichia coli, Salmonella spp. and Shigella spp. Here, we found that rac excision is induced during biofilm formation, and the isogenic stain without rac is more motile and forms more biofilms in nutrient-rich medium at early stages in E. coli K-12. Additionally, the presence of rac genes increases cell lysis during biofilm development. In most E. coli strains, rac is integrated into the ttcA gene which encodes a tRNA-thioltransferase. Rac excision in E. coli K-12 leads to a functional change of TtcA, which results in reduced fitness in the presence of carbenicillin. Additionally, we demonstrate that YdaQ (renamed as XisR) is the excisionase of rac in E. coli K-12, and that rac excision is induced by the stationary sigma factor RpoS through inducing xisR expression. Taken together, our results reveal that upon rac integration, not only are new genes introduced into the host, but also there is a functional change in a host enzyme. Hence, rac excision is tightly regulated by host factors to control its stability in the host genome under different stress conditions.

Physiological Function of Rac Prophage During Biofilm Formation and Regulation of Rac Excision in Escherichia coli K-12

PubMed Central

Liu, Xiaoxiao; Li, Yangmei; Guo, Yunxue; Zeng, Zhenshun; Li, Baiyuan; Wood, Thomas K.; Cai, Xingsheng; Wang, Xiaoxue

2015-01-01

Rac or rac-like prophage harbors many genes with important physiological functions, while it remains excision-proficient in several bacterial strains including Escherichia coli, Salmonella spp. and Shigella spp. Here, we found that rac excision is induced during biofilm formation, and the isogenic stain without rac is more motile and forms more biofilms in nutrient-rich medium at early stages in E. coli K-12. Additionally, the presence of rac genes increases cell lysis during biofilm development. In most E. coli strains, rac is integrated into the ttcA gene which encodes a tRNA-thioltransferase. Rac excision in E. coli K-12 leads to a functional change of TtcA, which results in reduced fitness in the presence of carbenicillin. Additionally, we demonstrate that YdaQ (renamed as XisR) is the excisionase of rac in E. coli K-12, and that rac excision is induced by the stationary sigma factor RpoS through inducing xisR expression. Taken together, our results reveal that upon rac integration, not only are new genes introduced into the host, but also there is a functional change in a host enzyme. Hence, rac excision is tightly regulated by host factors to control its stability in the host genome under different stress conditions. PMID:26530864

Controlling biofilm formation, prophage excision and cell death by rewiring global regulator H‐NS of Escherichia coli

PubMed Central

Hong, Seok Hoon; Wang, Xiaoxue; Wood, Thomas K.

2010-01-01

Summary The global regulator H‐NS of Escherichia coli controls genes related to stress response, biofilm formation and virulence by recognizing curved DNA and by silencing acquired genes. Here, we rewired H‐NS to control biofilm formation using protein engineering; H‐NS variant K57N was obtained that reduces biofilm formation 10‐fold compared with wild‐type H‐NS (wild‐type H‐NS increases biofilm formation whereas H‐NS K57N reduces it). Whole‐transcriptome analysis revealed that H‐NS K57N represses biofilm formation through its interaction with the nucleoid‐associated proteins Cnu and StpA and in the absence of these proteins, H‐NS K57N was unable to reduce biofilm formation. Significantly, H‐NS K57N enhanced the excision of defective prophage Rac while wild‐type H‐NS represses excision, and H‐NS controlled only Rac excision among the nine resident E. coli K‐12 prophages. Rac prophage excision not only led to the change in biofilm formation but also resulted in cell lysis through the expression of toxin HokD. Hence, the H‐NS regulatory system may be evolved through a single‐amino‐acid change in its N‐terminal oligomerization domain to control biofilm formation, prophage excision and apoptosis. PMID:21255333

Union Women, the Tobacco Industry, and Excise Taxes

PubMed Central

Balbach, Edith D.; Campbell, Richard B.

2009-01-01

Between 1987 and 1997, the tobacco industry used the issue of cigarette excise tax increases to create a political partnership with the Coalition of Labor Union Women (CLUW), a group representing female trade unionists in the U.S. This paper documents how the industry created this relationship and the lessons tobacco-control advocates can learn from the industry’s example, in order to mitigate possible unintended consequences of advocating excise tax increases In 1998, under the terms of the Master Settlement Agreement, the tobacco industry began making documents produced in litigation available publicly. Currently, approximately 50 million pages are available online, including substantial documentation of the industry–CLUW relationship. For this study, a comprehensive search of these documents was conducted. The tobacco industry encouraged CLUW’s opposition to excise tax increases by emphasizing the economic regressivity of these taxes, discussing excise taxes generically to deflect attention from cigarettes, and encouraging opposition to earmarking cigarette taxes to pay for specific programs. In addition, CLUW received at least $221,500 in financial support between 1987 and 1997 and in-kind support for its conferences, membership materials, and other services. Excise tax increases, if pursued without considering the impacts they may have on low-SES populations, may have unintended consequences. In this case, such proposals may have helped to create a relationship between CLUW and the tobacco industry. Because excise taxes are endorsed in the Framework Convention on Tobacco Control, tobacco-control advocates must understand how to build relationships with low-SES populations and mitigate potential alliances with the tobacco industry. PMID:19591750

Simulating the impact of excise taxation for disease prevention in low-income and middle-income countries: an application to South Africa

PubMed Central

Summan, Amit; Tugendhaft, Aviva; Laxminarayan, Ramanan; Hofman, Karen

2018-01-01

Introduction Excise taxes are policy tools that have been applied internationally with some success to reduce consumption of products adversely impacting population health including tobacco, alcohol and increasingly junk foods and sugary beverages. As in other low-income and middle-income countries, South Africa faces a growing burden of lifestyle diseases; accordingly we simulate the impact of multiple excise tax interventions in this setting. Methods We construct a mathematical model to simulate the health and revenue effects of increased excise taxes, which is adaptable to a variety of settings given its limited data requirements. Applying the model to South Africa, we simulate the impact of increased tax rates on tobacco and beer and of the introduction of a tax on sugar-sweetened beverages (SSB). Drawing on surveys of product usage and risk factor prevalence, the model uses a potential impact fraction to simulate the health effects of tax interventions. Results Adopting an excise rate of 60% on tobacco would result in a gain of 858 923 life-years (95% uncertainty interval (UI) 480 188 to 1 310 329), while adopting an excise rate of 25% on beer would result in a gain of 568 063 life-years (95% UI 412 110 to 775 560) and the adoption of a 20% tax on SSBs would result in a gain of 688 719 life-years (95% UI 321 788 to 1 079 653). Conclusion More aggressive excise tax policies on tobacco, beer and SSBs in South Africa could result in meaningful improvements in population health and raised revenue. PMID:29515917

Simulating the impact of excise taxation for disease prevention in low-income and middle-income countries: an application to South Africa.

PubMed

Stacey, Nicholas; Summan, Amit; Tugendhaft, Aviva; Laxminarayan, Ramanan; Hofman, Karen

2018-01-01

Excise taxes are policy tools that have been applied internationally with some success to reduce consumption of products adversely impacting population health including tobacco, alcohol and increasingly junk foods and sugary beverages. As in other low-income and middle-income countries, South Africa faces a growing burden of lifestyle diseases; accordingly we simulate the impact of multiple excise tax interventions in this setting. We construct a mathematical model to simulate the health and revenue effects of increased excise taxes, which is adaptable to a variety of settings given its limited data requirements. Applying the model to South Africa, we simulate the impact of increased tax rates on tobacco and beer and of the introduction of a tax on sugar-sweetened beverages (SSB). Drawing on surveys of product usage and risk factor prevalence, the model uses a potential impact fraction to simulate the health effects of tax interventions. Adopting an excise rate of 60% on tobacco would result in a gain of 858 923 life-years (95% uncertainty interval (UI) 480 188 to 1 310 329), while adopting an excise rate of 25% on beer would result in a gain of 568 063 life-years (95% UI 412 110 to 775 560) and the adoption of a 20% tax on SSBs would result in a gain of 688 719 life-years (95% UI 321 788 to 1 079 653). More aggressive excise tax policies on tobacco, beer and SSBs in South Africa could result in meaningful improvements in population health and raised revenue.