Anatomical location of the surgically identifiable bladder branch of the inferior hypogastric plexus for nerve-sparing radical hysterectomy.

Objective: We aimed to demonstrate the entire structure of the inferior hypogastric plexus in the female pelvis focusing on surgically identifiable nerve bundles to the urinary bladder. Methods: Surgical videos of transabdominal nerve-sparing radical hysterectomy for 10 patients with cervical cancer at International Federation of Gynecology and Obstetrics (FIGO 2009) stage IB1-IIB were retrospectively analyzed. The paracervical tissue dorsal to the ureter was separated into the lateral component (dorsal layer of the vesicouterine ligament) and medial component (paracolpium) using Okabayashi's technique. Any bundle-like structures in the paracervical area were isolated and divided using cold scissors, and each cut edge was inspected to determine whether the bundle was a blood vessel or a nerve. Results: In all cases, the surgically identifiable nerve bundle of the bladder branch was identified on the rectovaginal ligament running parallel and dorsal to the vaginal vein of the paracolpium. The bladder branch was revealed only after complete division of the vesical veins in the dorsal layer of the vesicouterine ligament where no definitive nerve bundles were observed. The bladder branch was derived laterally from the pelvic splanchnic nerve and medially from the inferior hypogastric plexus. Conclusions: The surgical identification of the nerve bundle of the bladder branch is essential for a safe and secure nerve-sparing radical hysterectomy. The preservation of the surgically identifiable bladder branch from the pelvic splanchnic nerve as well as from the inferior hypogastric plexus can provide satisfactory postoperative voiding function.

Avascular spaces in radical hysterectomy.

The most common cancer in women worldwide is cervical cancer. For early-stage disease the standard treatment is radical hysterectomy. One of the main issues faced by surgeons performing a radical hysterectomy is the wide variation in the terminology used to define the procedure and the nomenclature used to describe the anatomical spaces critical to the success of the surgery. The aim of this review was to synthesize currently used anatomical landmarks with relation to surgical avascular spaces for the performance of radical hysterectomy.A computer-based comprehensive review of the MEDLINE, Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, Embase, and SciSearch databases, as well as National Comprehensive Cancer Network and European Society of Gynaecological Oncology guidelines, was performed. With all relevant data collected, and previous anatomical studies during surgeries and on cadavers performed by authors, a manuscript of the definition of avascular spaces, methods of dissection, and anatomical limits was prepared.Avascular pelvic spaces developed during radical hysterectomy, such as the paravesical, pararectal, ureter tunnel, and paravaginal, were considered and included in the manuscript. A clear definition of avascular spaces may aid a better understanding of the anatomical aspects of the radical hysterectomy. It could improve surgeon knowledge of the structures that need to be preserved and those that need to be resected during a radical hysterectomy. Additionally, the detailed exposure of anatomical boundaries will facilitate the appropriate tailored radicality depending on the risk factors of the disease. Moreover, knowledge of these spaces could make pelvic surgery safer and easier for other types of gynecological and non-gynecological procedures.

Double-strand breaks: When DNA repair events accidentally meet.

The cellular response to alkylation damage is complex, involving multiple DNA repair pathways and checkpoint proteins, depending on the DNA lesion, the cell type, and the cellular proliferation state. The repair of and response to O-alkylation damage, primarily O6-methylguaine DNA adducts (O6-mG), is the purview of O6-methylguanine-DNA methyltransferase (MGMT). Alternatively, this lesion, if left un-repaired, induces replication-dependent formation of the O6-mG:T mis-pair and recognition of this mis-pair by the post-replication mismatch DNA repair pathway (MMR). Two models have been suggested to account for MMR and O6-mG DNA lesion dependent formation of DNA double-strand breaks (DSBs) and the resulting cytotoxicity - futile cycling and direct DNA damage signaling. While there have been hints at crosstalk between the MMR and base excision repair (BER) pathways, clear mechanistic evidence for such pathway coordination in the formation of DSBs has remained elusive. However, using a novel protein capture approach, Fuchs and colleagues have demonstrated that DSBs result from an encounter between MMR-induced gaps initiated at alkylation induced O6-mG:C sites and BER-induced nicks at nearby N-alkylation adducts in the opposite strand. The accidental encounter between these two repair events is causal in the formation of DSBs and the resulting cellular response, documenting a third model to account for O6-mG induced cell death in non-replicating cells. This graphical review highlights the details of this Repair Accident model, as compared to current models, and we discuss potential strategies to improve clinical use of alkylating agents such as temozolomide, that can be inferred from the Repair Accident model.

Crosstalk between repair pathways elicits double-strand breaks in alkylated DNA and implications for the action of temozolomide.

Temozolomide (TMZ), a DNA methylating agent, is the primary chemotherapeutic drug used in glioblastoma treatment. TMZ induces mostly N-alkylation adducts (N7-methylguanine and N3-methyladenine) and some O6-methylguanine (O6mG) adducts. Current models propose that during DNA replication, thymine is incorporated across from O6mG, promoting a futile cycle of mismatch repair (MMR) that leads to DNA double-strand breaks (DSBs). To revisit the mechanism of O6mG processing, we reacted plasmid DNA with N-methyl-N-nitrosourea (MNU), a temozolomide mimic, and incubated it in Xenopus egg-derived extracts. We have shown that in this system, MMR proteins are enriched on MNU-treated DNA and we observed robust, MMR-dependent, repair synthesis. Our evidence also suggests that MMR, initiated at O6mG:C sites, is strongly stimulated in cis by repair processing of other lesions, such as N-alkylation adducts. Importantly, MNU-treated plasmids display DSBs in extracts, the frequency of which increases linearly with the square of alkylation dose. We suggest that DSBs result from two independent repair processes, one involving MMR at O6mG:C sites and the other involving base excision repair acting at a nearby N-alkylation adduct. We propose a new, replication-independent mechanism of action of TMZ, which operates in addition to the well-studied cell cycle-dependent mode of action.

Enrichment of plasmid pool from E. coli for mass sequencing to detect untargeted mutagenic events.

Translesion synthesis (TLS) is an event to cope with DNA damages. During TLS, the responsible TLS polymerase frequently elicits untargeted mutagenesis as potentially a source of genetic diversity. Identifying such untargeted mutations in vivo is challenging due to the bulk of DNA that does not undergo TLS. Here, we present a protocol to enrich a plasmid pool that underwent Pol V-mediated TLS in Escherichia coli for mass sequencing. The concept of this protocol could be applied into any species. For complete details on the use and execution of this protocol, please refer to Isogawa et al. (2018).

Targeting Dormant Ovarian Cancer Cells In Vitro and in an In Vivo Mouse Model of Platinum Resistance.

Spheroids exhibit drug resistance and slow proliferation, suggesting involvement in cancer recurrence. The protein kinase C inhibitor UCN-01 (7-hydroxystaurosporine) has shown higher efficacy against slow proliferating and/or quiescent ovarian cancer cells. In this study, tumorigenic potential was assessed using anchorage-independent growth assays and spheroid-forming capacity, which was determined with ovarian cancer cell lines as well as primary ovarian cancers. Of 12 cell lines with increased anchorage-independent growth, 8 formed spheroids under serum-free culture conditions. Spheroids showed reduced proliferation (P < 0.0001) and Ki-67 immunostaining (8% vs. 87%) relative to monolayer cells. Spheroid formation was associated with increased expression of mitochondrial pathway genes (P ≤ 0.001) from Affymetrix HT U133A gene expression data. UCN-01, a kinase inhibitor/mitochondrial uncoupler that has been shown to lead to Puma-induced mitochondrial apoptosis as well as ATP synthase inhibitor oligomycin, demonstrated effectiveness against spheroids, whereas spheroids were refractory to cisplatin and paclitaxel. By live in vivo imaging, ovarian cancer xenograft tumors were reduced after primary treatment with carboplatin. Continued treatment with carboplatin was accompanied by an increase in tumor signal, whereas there was little or no increase in tumor signal observed with subsequent treatment with UCN-01 or oltipraz. Taken together, our findings suggest that genes involved in mitochondrial function in spheroids may be an important therapeutic target in preventing disease recurrence.

A Comprehensive View of Translesion Synthesis in Escherichia coli.

The lesion bypass pathway, translesion synthesis (TLS), exists in essentially all organisms and is considered a pathway for postreplicative gap repair and, at the same time, for lesion tolerance. As with the saying "a trip is not over until you get back home," studying TLS only at the site of the lesion is not enough to understand the whole process of TLS. Recently, a genetic study uncovered that polymerase V (Pol V), a poorly expressed Escherichia coli TLS polymerase, is not only involved in the TLS step per se but also participates in the gap-filling reaction over several hundred nucleotides. The same study revealed that in contrast, Pol IV, another highly expressed TLS polymerase, essentially stays away from the gap-filling reaction. These observations imply fundamentally different ways these polymerases are recruited to DNA in cells. While access of Pol IV appears to be governed by mass action, efficient recruitment of Pol V involves a chaperone-like action of the RecA filament. We present a model of Pol V activation: the 3' tip of the RecA filament initially stabilizes Pol V to allow stable complex formation with a sliding ß-clamp, followed by the capture of the terminal RecA monomer by Pol V, thus forming a functional Pol V complex. This activation process likely determines higher accessibility of Pol V than of Pol IV to normal DNA. Finally, we discuss the biological significance of TLS polymerases during gap-filling reactions: error-prone gap-filling synthesis may contribute as a driving force for genetic diversity, adaptive mutation, and evolution.

Chromatin Pull-Down Methodology Based on DNA Triple Helix Formation.

Identification of the protein complexes associated with defined DNA sequence elements is essential to understand the numerous transactions in which DNA is involved, such as replication, repair, transcription, and chromatin dynamics. Here we describe two protocols, IDAP (Isolation of DNA Associated Proteins) and CoIFI (Chromatin-of-Interest Fragment Isolation), that allow for isolating DNA/protein complexes (i.e., nucleoprotein elements) by means of a DNA capture tool based on DNA triple helix (triplex) formation. Typically, IDAP is used to capture proteins that bind to a given DNA element of interest (e.g., a specific DNA sequence, an unusual DNA structure, a DNA lesion) that can be introduced at will into plasmids. The plasmids are immobilized by means of a triplex-forming probe on magnetic beads and incubated in nuclear extracts; by using in parallel a control plasmid (that lacks the DNA element of interest), proteins that preferentially bind to the DNA element of interest are captured and identified by mass spectrometry. Similarly, CoIFI also uses a triplex-forming probe to capture a specific chromatin fragment from a cultured cell line that has been engineered to contain multiple copies of the DNA element of interest.

Nerve-sparing radical hysterectomy: steps to standardize surgical technique.

AIM: The primary objective of this review was to study and analyze techniques of nerve-sparing radical hysterectomy so as to be able to characterize and elucidate intricate steps for the dissection of each component of the pelvic autonomic nerve plexuses during nerve-sparing radical hysterectomy. METHODS: This review was based on a five-step study design that included searching for relevant publications, selecting publications by applying inclusion and exclusion criteria, quality assessment of the identified studies, data extraction, and data synthesis. RESULTS: There are numerous differences in the published literature concerning nerve-sparing radical hysterectomy including variations in techniques and surgical approaches. Techniques that claim to be nerve-sparing by staying above the dissection level of the hypogastric nerves do not highlight the pelvic splanchnic nerve, do not take into account the intra-operative patient position, nor the fact that the bladder branches leave the inferior hypogastric plexus in a ventrocranial direction, and the fact that inferior hypogastric plexus will be drawn cranially with the vaginal walls (if this is not recognized and isolated earlier) above the level of hypogastric nerves by drawing the uterus cranially during the operation. CONCLUSIONS: The optimal nerve-sparing radical hysterectomy technique has to be radical (type C1) and must describe surgical steps to highlight all three components of the pelvic autonomic nervous system (hypogastric nerves, pelvic splanchnic nerves, and the bladder branches of the inferior hypogastric plexus). Recognizing the pelvic splanchnic nerves in the caudal parametrium and the isolation of the bladder branches of the inferior hypogastic plexus requires meticulous preparation of the caudal part of the ventral parametrium.

Chronological Switch from Translesion Synthesis to Homology-Dependent Gap Repair In Vivo.

Cells are constantly exposed to endogenous and exogenous chemical and physical agents that damage their genome by forming DNA lesions. These lesions interfere with the normal functions of DNA such as transcription and replication, and need to be either repaired or tolerated. DNA lesions are accurately removed via various repair pathways. In contrast, tolerance mechanisms do not remove lesions but only allow replication to proceed despite the presence of unrepaired lesions. Cells possess two major tolerance strategies, namely translesion synthesis (TLS), which is an error-prone strategy and an accurate strategy based on homologous recombination (homology-dependent gap repair [HDGR]). Thus, the mutation frequency reflects the relative extent to which the two tolerance pathways operate in vivo. In the present paper, we review the present understanding of the mechanisms of TLS and HDGR and propose a novel and comprehensive view of the way both strategies interact and are regulated in vivo.

Pol V-Mediated Translesion Synthesis Elicits Localized Untargeted Mutagenesis during Post-replicative Gap Repair.

In vivo, replication forks proceed beyond replication-blocking lesions by way of downstream repriming, generating daughter strand gaps that are subsequently processed by post-replicative repair pathways such as homologous recombination and translesion synthesis (TLS). The way these gaps are filled during TLS is presently unknown. The structure of gap repair synthesis was assessed by sequencing large collections of single DNA molecules that underwent specific TLS events in vivo. The higher error frequency of specialized relative to replicative polymerases allowed us to visualize gap-filling events at high resolution. Unexpectedly, the data reveal that a specialized polymerase, Pol V, synthesizes stretches of DNA both upstream and downstream of a site-specific DNA lesion. Pol V-mediated untargeted mutations are thus spread over several hundred nucleotides, strongly eliciting genetic instability on either side of a given lesion. Consequently, post-replicative gap repair may be a source of untargeted mutations critical for gene diversification in adaptation and evolution.

Versatile and efficient chromatin pull-down methodology based on DNA triple helix formation.

The goal of present paper is to develop a reliable DNA-based method for isolation of protein complexes bound to DNA (Isolation of DNA Associated Proteins: IDAP). We describe a robust and versatile procedure to pull-down chromatinized DNA sequences-of-interest by formation of a triple helix between a sequence tag present in the DNA and a complementary triple helix forming oligonucleotide (TFO) coupled to a desthiobiotin residue. Following optimization to insure efficient recovery of native plasmids via TFO probe in vitro, the procedure is shown to work under various experimental situations. For instance, it allows capture proteins associated to plasmids hosted in E. coli, and is also successfully applied to recovering nucleosomes in vitro opening many possibilities to study post translational modifications of histones in a genuine nucleosome context. Incubation in human nuclear extracts of a plasmid carrying a NF-κB model promoter is shown to pull-down a specific transcription factor. Finally, isolation of a specific locus from human genomic chromatin has been successfully achieved (Chromatin-of-Interest Fragment Isolation: CoIFI). In conclusion, the methodology can be implemented for capturing proteins that specifically bind to any sequence-of-interest, DNA adduct or secondary structure provided a short sequence tag for triple helix formation is located nearby.

Processing closely spaced lesions during Nucleotide Excision Repair triggers mutagenesis in E. coli.

It is generally assumed that most point mutations are fixed when damage containing template DNA undergoes replication, either right at the fork or behind the fork during gap filling. Here we provide genetic evidence for a pathway, dependent on Nucleotide Excision Repair, that induces mutations when processing closely spaced lesions. This pathway, referred to as Nucleotide Excision Repair-induced Mutagenesis (NERiM), exhibits several characteristics distinct from mutations that occur within the course of replication: i) following UV irradiation, NER-induced mutations are fixed much more rapidly (t ½ ≈ 30 min) than replication dependent mutations (t ½ ≈ 80-100 min) ii) NERiM specifically requires DNA Pol IV in addition to Pol V iii) NERiM exhibits a two-hit dose-response curve that suggests processing of closely spaced lesions. A mathematical model let us define the geometry (infer the structure) of the toxic intermediate as being formed when NER incises a lesion that resides in close proximity of another lesion in the complementary strand. This critical NER intermediate requires Pol IV / Pol II for repair, it is either lethal if left unrepaired or mutation-prone when repaired. Finally, NERiM is found to operate in stationary phase cells providing an intriguing possibility for ongoing evolution in the absence of replication.

Identification and prevalence of adverse drug events caused by potentially inappropriate medication in homebound elderly patients: a retrospective study using a nationwide survey in Japan.

OBJECTIVES: A nationwide large-scale survey was conducted to identify the prevalence and causal medications of adverse drug events (ADEs) that are caused by potentially inappropriate medications (PIMs) given to homebound elderly patients, factors associated with ADEs, and measures taken by pharmacists to manage ADEs and their effects on ADEs. SETTINGS: A questionnaire was mailed to 3321 pharmacies nationwide. It asked about the details of PIMs and ADEs of up to 5 patients for whom home visits were provided by a pharmacist. Questionnaire forms were filled in by pharmacists who visited the patients. DESIGN AND PARTICIPANTS: Between 23 January and 13 February 2013, comprehensive assessment forms were sent to 3321 pharmacies. Data collected from 1890 pharmacies including data of 4815 patients were analysed and 28 patients of unknown sex were excluded. Their average age was 82.7 years. PIMs were identified based on the 2003 Beers Criteria Japan. RESULTS: There were 600 patients who did not provide valid answers regarding the medications. In the remaining 4243 patients, one or more medications that were considered to be PIMs had been prescribed to 48.4% of patients. PIM-induced ADEs were found in 8% of these patients by pharmacists during home visits. The top ADE-inducing medications were strong anticholinergic antihistamines, benzodiazepines, sulpiride and digoxin. The most common ADEs associated with benzodiazepines were frequent lightheadedness, somnolence and sleepiness, which increase the risk of falls and subsequent fractures in elderly patients. The following factors associated with ADEs were identified: sex, pharmacist awareness of prescription issues, frequency of visits and time spent at patients' homes, and the frequency of detailed checks for patient adverse reactions by pharmacists. CONCLUSIONS: The PIM prevalence associated with home healthcare in Japan was relatively high, as reported in previous studies. The present study suggests that pharmacists could reduce the incidence of PIMs and consequent ADEs.

[Nationwide study on relations between workload and outcomes of home visiting service by community pharmacists].

A nationwide survey was conducted to verify relations between the workload of home-visiting service by community pharmacists and outcomes. Data were collected on 5447 patients from 1890 pharmacies. Most (61.9%) pharmacists visited patients' homes twice monthly, spending there a net average of 20.6 work minutes. At the time of the survey, 29.8% of the patients had improvement of adherence compared with at start of home visits; 65.5% had no change, and 1.4% had gotten worse. Similarly, 41.6% had decreased unused medications, 54.4% had no change, and 2.3% had increased. Home-visiting pharmacists found adverse drug events (ADEs) caused by drug administration in 14.4% of their patients. They dealt with 44.2% of these cases by discontinuing administration of the responsible drug, 24.5% by reducing the dosage, and 18.3% by changing drugs, with a total of 88.1% having been improved. Prescription changes intended to correct problems occurred in 37.1% of the patients. In patients whom the pharmacists visited more often, a higher percent had ADEs, had their prescription changed to correct problems, and had improved adherence and unused medications. The average actual work time was longer in patients whose outcomes improved than in those whose outcomes did not. A higher involvement in homecare by pharmacists was found to improve outcomes of drug treatment.

Surgical and systemic management of endometrial cancer: an international survey.

PURPOSE: To ascertain the spectrum of clinical management of endometrial carcinoma (EC) the largest international survey was conducted to evaluate and identify differences worldwide. METHODS: After validation of a 15-item questionnaire regarding surgical and adjuvant treatment of EC in Germany, an English-adapted questionnaire was put online and posted to all the major gynecological cancer Societies worldwide for further distribution commencing in 2010 and continued for 26 months. RESULTS: A total of 618 Institutions around the world participated: Central Europe (CE), Southern Europe (SE), Northern Europe (NE), Asia and USA/Canada/UK. Both a therapeutic and staging value was attributed to systematic pelvic and paraaortic lymph node dissection (LND) in CE (74.6%) and in Asia (67.2%), as opposed to USA/UK where LND was mainly for staging purposes (53.5%; p < 0.001). LND was performed up to the renal veins in CE in 86.8%, in Asia in 80.8%, in USA/UK in 51.2% and in SE in 45.1% (p < 0.001) of cases. In advanced disease, centers from Asia were treated most with adjuvant chemotherapy alone (93.6%), as opposed to centers in SE, CE and UK/USA that employed combination chemo-radiotherapy in 90.9% (p < 0.001) of cases. Paclitaxel/carboplatin was mostly used followed by doxorubicin/cisplatin (75 vs. 23.3%; p < 0.001). In total, 94% of all participants supported the concept of treating EC patients within appropriate clinical trials. CONCLUSIONS: There is broad range in both the surgical and adjuvant treatment of EC across different countries. Large-scale multicenter prospective trials are warranted to establish consistent, evidence-based guidelines to optimize treatment worldwide.

Translesion DNA synthesis and mutagenesis in prokaryotes.

The presence of unrepaired lesions in DNA represents a challenge for replication. Most, but not all, DNA lesions block the replicative DNA polymerases. The conceptually simplest procedure to bypass lesions during DNA replication is translesion synthesis (TLS), whereby the replicative polymerase is transiently replaced by a specialized DNA polymerase that synthesizes a short patch of DNA across the site of damage. This process is inherently error prone and is the main source of point mutations. The diversity of existing DNA lesions and the biochemical properties of Escherichia coli DNA polymerases will be presented. Our main goal is to deliver an integrated view of TLS pathways involving the multiple switches between replicative and specialized DNA polymerases and their interaction with key accessory factors. Finally, a brief glance at how other bacteria deal with TLS and mutagenesis is presented.

Expression of p53 and p21(WAF-1), apoptosis, and proliferation of smooth muscle cells in normal myometrium during the menstrual cycle: implication of DNA damage and repair for leiomyoma development.

Uterine leiomyoma is the most common tumor in the female genital tract, although its pathogenesis remains unclear. Molecular analyses have demonstrated that each leiomyoma nodule is monoclonal and harbors various DNA abnormalities, suggesting that DNA damage in normal smooth muscle cells plays an important role in the pathogenesis of leiomyoma. The aim of this study is to evaluate precisely when and where DNA damage occurs in the myometrium. The localization of damaged, apoptotic, and proliferating cells was evaluated by immunohistochemical staining of p53, p21(WAF-1), TUNEL, and the cell proliferation marker, Ki-67, in normal myometrium during the menstrual cycle. p53-positive cells and p21(WAF-1)-positive cells were observed during the follicular phase, mostly in the submucosal layer of the myometrium. TUNEL-positive cells were sporadically identified in this layer during either the menstrual or follicular phase. In contrast, the number of Ki-67-positive cells was higher in the luteal phase. These results suggest that DNA damage, repair, and apoptosis occur cyclically in normal myometrium during the follicular phase. In addition, smooth muscle cells proliferate in the luteal phase, which may be a vulnerable period for DNA damage. Thus, these cyclic events during the menstrual cycle may contribute to a high incidence of leiomyoma development.

Escherichia coli DNA polymerase III is responsible for the high level of spontaneous mutations in mutT strains.

Reactive oxygen species induce oxidative damage in DNA precursors, i.e. dNTPs, leading to point mutations upon incorporation. Escherichia coli mutT strains, deficient in the activity hydrolysing 8-oxo-7,8-dihydro-2'-deoxyguanosine 5'-triphosphate (8-oxo-dGTP), display more than a 100-fold higher spontaneous mutation frequency over the wild-type strain. 8-oxo-dGTP induces A to C transversions when misincorporated opposite template A. Here, we report that DNA pol III incorporates 8-oxo-dGTP ≈ 20 times more efficiently opposite template A compared with template C. Single, double or triple deletions of pol I, pol II, pol IV or pol V had modest effects on the mutT mutator phenotype. Only the deletion of all four polymerases led to a 70% reduction of the mutator phenotype. While pol III may account for nearly all 8-oxo-dGTP incorporation opposite template A, it only extends ≈ 30% of them, the remaining 70% being extended by the combined action of pol I, pol II, pol IV or pol V. The unique property of pol III, a C-family DNA polymerase present only in eubacteria, to preferentially incorporate 8-oxo-dGTP opposite template A during replication might explain the high spontaneous mutation frequency in E. coli mutT compared with the mammalian counterparts lacking the 8-oxo-dGTP hydrolysing activities.