Adoption of an incident learning system in a regionally expanding academic radiation oncology department

Aim and BackgroundWe describe a successful implementation of a departmental incident learning system (ILS) across a regionally expanding academic radiation oncology department, dovetailing with a structured integration of the safety and quality program across clinical sites.Materials and methods mOver 6 years between 2011 and 2017, a long-standing departmental ILS was deployed to 4 clinical locations beyond the primary clinical location where it had been established. We queried all events reported to the ILS during this period and analyzed trends in reporting by clinical site. The chi-square test was used to determine whether differences over time in the rate of reporting were statistically significant. We describe a synchronous development of a common safety and quality program over the same period.ResultsThere was an overall increase in the number of event reports from each location over the time period from 2011 to 2017. The percentage increase in reported events from the first year of implementation to 2017 was 457% in site 1, 166.7% in site 2, 194.3% in site 3, 1025% in site 4, and 633.3% in site 5, with an overall increase of 677.7%. A statistically significant increase in the rate of reporting was seen from the first year of implementation to 2017 (p < 0.001 for all sites).ConclusionsWe observed significant increases in event reporting over a 6-year period across 5 regional sites within a large academic radiation oncology department, during which time we expanded and enhanced our safety and quality program, including regional integration. Implementing an ILS and structuring a safety and quality program together result in the successful integration of the ILS into existing departmental infrastructure.     

Incidence of soft tissue sarcoma in Taiwan: A nationwide population-based study (2007–2013)

BackgroundAsian studies on soft tissue sarcoma (STS) incidence, irrespective of the primary site, are scant.MethodsSTS data were acquired from the population-based 2007–2013 Taiwan Cancer Registry of the Health and Welfare Data Science Center, Taiwan. Histological subtype-, site-, sex-, and age-specific STS incidence rates were analyzed according to the 2013 classification of the World Health Organization.ResultsIn total, 11,393 patients with an age-standardized incidence rate (ASIR) of 5.62 (95% confidence interval, 5.51–5.73) per 100,000 person-years were identified. Overall, a male predominance (sex-standardized incidence rate ratio, 1.2) was noted, and the rate increased with age, peaking at >75 years. Approximately 30% of STSs occurred in connective, subcutaneous, and other soft tissues and 70% in other sites. In addition to connective, subcutaneous, and other soft tissues, the three most common primary sites were the stomach (15.9%), skin (14.3%), and small intestines (10.5%). Gastrointestinal stromal tumor was the most common subtype (29.2%; ASIR, 1.55/100,000 person-years), followed by liposarcoma (11.5%; ASIR, 0.63/100,000 person-years) and leiomyosarcoma (9.7%; ASIR, 0.53/100,000 person-years). Compared with relevant data from Western countries, the incidence rate of angiosarcomas was higher than that in other regions, whereas the incidence rates of leiomyosarcoma and Kaposi sarcoma were lower than those in other regions.ConclusionSTS incidence varied by histological subtype, sex, age, and primary site in an Asian population. Our results suggested regional and racial discrepancies in the incidence rates of certain STS subtypes.     

Development of a Newborn Screening Program for Critical Congenital Heart Disease (CCHD) in Taipei

BackgroundEarly detection of critical congenital heart disease (CCHD) can significantly reduce morbidity and mortality among newborns. We investigate the feasibility of implementing a community-based newborn CCHD screening program in Taipei.MethodsTwelve birthing facilities in Taipei participated in a trial screening program between October 1, 2013, and March 31, 2014. Newborns underwent pulse oximetry at 24–36 h old, with probes attached to the right hand and one lower limb. Any screening saturation ≥95% in either extremity, with an absolute difference of ≤3% between the right hand and foot, was accepted as a screening pass. A screening result was considered as a fail if the oxygen saturation was <95% at either probe site, on 3 separate occasions, each separated by 30 min or the first result was <95% at either probe site, and any subsequent oxygen saturation measurement was <90%. Public health nurses would follow up all missed or refused cases.ResultsOf the 6,387 live births, 6,296 newborns (coverage rate: 6,296/6,387 = 98.6%) underwent appropriate pulse oximetry screening. Sixteen newborns (0.25%) were reported to have a failed screening result. Five of these screen positive newborns were confirmed with CCHD; two of them were diagnosed solely attributed to the failed screening results. The false-positive rate was 0.18%. Implementing a 6-month screening program for CCHD produced good case detection rate, while using efficient screening and referral systems.ConclusionThis program was successful in integrating screening, referral and public health tracking systems. The protocol outlined in this report could provide a community-based model for worldwide implementation.     

The association of urbanicity and travel time with lung cancer screening utilization

BackgroundTo examine 1) the rate of lung cancer screening (LCS) utilization in a large healthcare system in South Carolina; 2) associations of urbanicity and travel time with LCS utilization.MethodsLCS-eligible patients from 2019 were identified. The outcome was LCS utilization. The exposures were zip-code level urbanicity and travel time from the centroid of zip-code area to the nearest screening site (<10,10-<20, ≥20 min). Covariates included age, sex, race, marital status, insurance, body mass index, chronic obstructive pulmonary disease, Charlson Comorbidity Index (0, 1, 2, ≥3), and zip-code level median income. Chi-square tests and logistic regressions were employed.ResultsThe analysis included 6930 patients, among whom 1432 (20.66%) received LCS. After adjusting for covariates, living in a non-metropolitan area (adjusted odds ratio: 0.32; 95% confidence interval: 0.26–0.40) and having longer travel time (0.80 [0.65–0.98] and 0.68 [0.54–0.86] for 10-<20 and ≥20 min travel time, respectively, compared to <10 min travel time) were significantly associated with lower odds of LCS utilization.ConclusionsThe LCS utilization rate of a healthcare system was about 20% in 2019. Living in non-metropolitan areas or having longer travel time to LCS site were associated with lower LCS utilization.     

Prognostic significance of accelerated ventricular response during radiofrequency ablation of premature ventricular complexes

BackgroundAccelerated ventricular response is frequently observed during radiofrequency ablation (RFA) of premature ventricular complexes (PVCs). We hypothesized that acceleration indicates an appropriate site and adequate injury to the arrhythmogenic tissue, and sought to investigate its value in predicting the outcome.MethodsWe retrospectively analyzed RFA procedures performed for PVCs in our institution from 2011 to 2019.ResultsFifty-eight patients (29 male; age 42.7 ± 15.6 years) underwent 62 RFA procedures. The most common site was the right ventricular outflow tract (67.7%). Acute success was seen in 88.7%. Accelerated ventricular response was observed in 60.0% of the successful procedures. After a median follow-up of 14.0 months (IQR: 6.0–26.6 months), 16 patients had a recurrence. Recurrence was significantly lower in the group with acceleration than in the group without acceleration (12.5% vs. 57.1%; log-rank P < 0.001). The 1-year recurrence rate was 6.5% in the acceleration group and 41.6% in the group without acceleration. On multivariable analysis the adjusted hazard ratio was 0.17 (95% CI, 0.04–0.64; Cox regression P = 0.009). The sensitivity, specificity, positive predictive, and negative predictive values of accelerated response to predict long-term success were 75.7%, 75.0%, 87.5%, and 57.2%, respectively.ConclusionsThe recurrence after PVC ablation is significantly lower when an accelerated response was observed at the successful location during RFA. This can be an additional useful marker of long-term success.     

髁突-翼外肌解剖复位与游离复位治疗髁状突骨折的疗效比较

目的:比较髁突-翼外肌解剖复位与游离复位治疗髁状突骨折的疗效,促进髁突形态恢复。方法:收治的80例单侧髁状突骨折患者随机分为两组,每组40例,A组行髁突-翼外肌解剖复位术,B组行髁状突游离复位术,术后3个月、6个月观察髁突形态及下颌骨运动功能变化。结果:A组治愈率为90%,高于B组的70.00%(P0.05);术后3个月A组髁状突吸收、张口受限、开口偏斜、咬合关系紊乱、关节弹响发生率分别为12.50%、15.00%、15.00%、7.50%、12.50%,均低于B组的32.50%、35.00%、37.50%、25.00%、35.00%(P0.05);术后6个月A组张口受限、关节弹响发生率为5.00%、2.50%,均低于B组的20.00%、20.00%(P0.05);两组术后并发症发生率比较差异无统计学意义(P0.05)。结论:髁突-翼外肌解剖复位术保留髁状突骨折患者骨折断端血运,髁突形态及下颌骨运动能力恢复良好,疗效优于髁状突游离复位术。     

Patient non-attendance at urgent referral appointments for suspected cancer and its links to cancer diagnosis and one year mortality: A cohort study of patients referred on the Two Week Wait pathway

BackgroundThe ‘Two Week Wait’ policy aims to ensure patients with suspected cancer are seen within two weeks of referral. However, patient non-attendance can result in this target being missed. This study aimed to identify predictors of non-attendance; and analyse the relationship between attendance and outcomes including cancer diagnosis and early mortality.MethodsA cohort study of 109,433 adults registered at 105 general practices, referred to a cancer centre within a large NHS hospital trust (April 2009 to December 2016) on the ‘Two Week Wait’ pathway.Results5673 (5.2%) patients did not attend. Non-attendance was largely predicted by patient factors (younger and older age, male gender, greater deprivation, suspected cancer site, earlier year of referral, greater distance to the hospital) over practice factors (greater deprivation, lower Quality and Outcomes Framework score, lower cancer conversion rate, lower cancer detection rate). 10,360 (9.6%) patients were diagnosed with cancer within six months of referral (9.8% attending patients, 5.6% non-attending patients). Among these patients, 2029 (19.6%) died within 12 months of diagnosis: early mortality risk was 31.3% in non-attenders and 19.2% in attending patients.ConclusionsNon-attendance at urgent referral appointments for suspected cancer involves a minority of patients but happens in predictable groups. Cancer diagnosis was less likely in non-attending patients but these patients had worse early mortality outcomes than attending patients. The study findings have implications for cancer services and policy.     

Translation-Initiation Promoting Site on Transcripts of Highly Expressed Genes From Saccharomyces cerevisiae and the Role of Hairpin Stems to Position the Site Near the Initiation Codon

Abstract

It is reported that the AUG-upstream region on mRNAs of highly expressed genes from S. cerevisiae invariably possesses a translation-initiation promoting site, that can base pair with a well-conserved site on 18S rRNA during the formation of 40S initiation complex. Weak hairpin stem in the mRNA region between such a site and the initiation codon brings the site nearer to the initiation codon and also extends the length of base pairing. Such a base pairing can lead to a comparatively more stable 40S initiation complex, resulting in a higher rate of formation of the 80S initiation complex and consequently in an enhancement of the rate of initiation of translation. The site on 18S rRNA can interchange its base pairing between the site on mRNA and a well-conserved site on 25S rRNA in the formation of the 80S initiation complex.     

Collision risk and micro-avoidance rates of birds with wind turbines in Flanders

Capsule Local factors can lead to strong variation in mortality rate and collision risk that obscures possible effects of turbine size in wind farms.

Aims The impact of bird collisions was studied at eight land-based wind farm sites with a total of 66 small to large turbines in order to assess the mortality rate and collision risk.

Methods Searches for collision fatalities were performed under all turbines with a minimum search interval of 14 days. Mortality rate was calculated with corrections for available search area, scavenging and search efficiency. Flight movements of birds crossing five of the wind farm sites were recorded during a minimum of four days per site. Actual collision risk was then calculated as the number of collision fatalities relative to the average surveyed flight intensity.

Results Mortality rate was 21 birds per turbine per year on average. Most fatalities were local common species (e.g. gulls) but rarer species were also found (e.g. terns, raptors and waders). Collision risk of gulls was 0.05% and 0.08% on average for birds, respectively, flying at turbine and rotor height through the wind farms (0.09% and 0.14% maximum). Large gulls had a significant higher collision risk than small gulls at rotor height. Mortality rate and collision risk were not significantly related to turbine size. The results were integrated in a widely used collision risk model to obtain information of micro-avoidance, i.e. the proportion of birds that fly through the wind farm but avoid passing through the rotor swept area of the turbines. For gulls, this micro-avoidance was 96.1% and 96.3% on average for birds, respectively, flying at turbine and rotor height through the wind farms.

Conclusion The results indicate that local factors can lead to strong variation in mortality rate and collision risk that obscures possible effects of turbine size in wind farms. However, large turbines have more installed capacity (MW), so repowering wind farms with larger but fewer wind turbines, could reduce total mortality at certain locations.     

巨噬细胞装载纳米颗粒用于药物递送

目的:活细胞药物递送系统具有主动靶向至肿瘤部位,防止被免疫系统清除等诸多优势。本文提供了一种巨噬细胞负载纳米颗粒的递送方法,并探讨不同载药量对巨噬细胞的活性以及运动性的影响。方法:通过超声乳化法制备包载阿霉素的DOX@PLGA纳米颗粒。纳米粒度分析仪测量粒径和表面电位,透射电镜观察纳米颗粒形态。将DOX@PLGA纳米颗粒与巨噬细胞共同孵育,即得到负载DOX@PLGA纳米颗粒的巨噬细胞用以药物递送。然后通过CCK-8法、LDH法以及细胞迁移实验检测不同载药量情况下细胞活力水平、细胞损伤程度以及细胞运动性。结果:制备的DOX@PLGA纳米颗粒呈圆形或椭圆形,粒径为109.2±2.3 nm;表面电位为-45.0±2.0 m V;载药量为4.61%。当单个巨噬细胞负载0.15 pg DOX时细胞存活率为:71.5±4.4(%);细胞损伤率为:26.3±1.8(%);迁移率为:61.6±5.7(%)。结论:成功制备巨噬细胞负载DOX@PLGA纳米颗粒的递药系统,载药量适当的情况下载体细胞依然具有良好的活性和运动性。     

Regional Differences in Thyroid Cancer Presentation and Survival: a Seer Study

ObjectiveThe incidence of thyroid cancer has been steadily increasing. Several studies have identified gender and racial/ethnic differences in the incidence and prognosis of thyroid cancer. In this study, we sought to determine if the stage of presentation and survival rate of patients with thyroid cancer in the United States is affected by geographic region.MethodsUsing the Surveillance, Epidemiology, and End Results (SEER) database, we identified 100,404 patients diagnosed with thyroid cancer from 1973 through 2009. We assessed historical stage of diagnosis and cancer-free survival rate according to geographic region. To compare stages of diagnosis, we used multinomial logistic regression. To compare survival rates, we used Cox proportional hazards regression. Models were adjusted for age, year of diagnosis, cancer type, registry site, race/ethnicity, and stage.ResultsOf 100,404 patients, 52,902 (52.7%) were from the West, 17,915 (17.8%) from the East, 15,302 (15.2%) from the South, and 14,285 (14.2%) from the Midwest. Overall, most patients presented with localized disease. Those from the West had a higher risk of presenting with regional and distant metastases. When we double-stratified by cancer subtype and racial group, we found no significant associations between geographic region and cancer-free survival rate.ConclusionThe presentation stage and survival rate of patients with thyroid cancer differs by geographic region, but not within separate racial/ethnic groups. (Endocr Pract. 2013;19:998-1006)     

Anti-predator function of not covering eggs in the initial phase of nesting in Grey Partridge Perdix perdix: a field experiment

ABSTRACT

Capsule: An experiment in the field supports the hypothesis that Grey Partridges Perdix perdix purposely expose their first laid eggs in order to test the predation risk at their nest site.

Aims: To test the hypothesis that female Grey Partridges leave first laid eggs uncovered to assess the predation risk at their chosen nesting site.

Methods: Four area-independent experiments with artificial nests were used. Predation risk was estimated by daily nest failure rate. Generalized linear mixed-effects models were used in statistical analysis.

Results: We found that Grey Partridge females could predict nest site safety. At nest sites where the first uncovered egg was depredated, there was a higher predation risk for the whole clutch.

Conclusion: Our data statistically support the hypothesis that leaving the first egg uncovered serves to provide a more conspicuous bait for potential predators and could be a female tactic for better recognizing predation risk at a nesting site. Thus, if the first uncovered egg is depredated, the female may start a new clutch elsewhere without wasting investment in the clutch at a site under high predation risk.     

Clinical application of a gantry-attachable plastic scintillating plate dosimetry system in pencil beam scanning proton therapy beam monitoring

PurposeThe entrance beam fluence of therapeutic proton scanning beams can be monitored using a gantry-attachable plastic scintillating plate (GAPSP). This study evaluated the clinical application of the GAPSP using a method that measures intensity modulated proton therapy (IMPT) beams for patient treatment.MethodsIMPT beams for the treatment of nine patients, at sites that included the spine, head and neck, pelvis, and lung, were measured using the GAPSP, composed of an EJ-212 plastic scintillator and a CMOS camera. All energy layers distinguished by the GAPSP were accumulated to determine the dose distribution of the treatment field. The evaluated fields were compared with reference dose maps verified by quality assurance.ResultsComparison of dose distributions of evaluation treatment fields with reference dose distributions showed that the 3%/1 mm average gamma passing rate was 96.4%, independent of the treatment site, energy range and field size. When dose distributions were evaluated using the same criteria for each energy layer, the average gamma passing rate was 91.7%.ConclusionsThe GAPSP is a suitable, low-cost method for monitoring pencil beam scanning proton therapy, especially for non-spot scanning or additional collimation. The GAPSP can also estimate the treatment beam by the energy layer, a feature not common to other proton dosimetry tools.     

Descriptive epidemiology of cancer of unknown primary in South Korea, 1999–2017

BackgroundCancers of unknown primary (CUPs) are tumors found after metastasizing from unidentified primary sites; these tumors generally have unknown treatment strategies, expected treatment results, and prognosis. We assessed the epidemiological characteristics of CUPs in Korea.MethodsWe extracted records for 1999 through 2017 from the Korea Central Cancer Registry using the International Statistical Classification of Diseases and Related Health Problems (10th revision) codes for CUP as defined by the International Agency for Research on Cancer. Age-standardized rates and relative survival rates were calculated.ResultsThe CUPs constituted 2.1 % of the total number of cancer registrations in 1999, declining to 0.7 % in 2017. The incidence rate decreased for both sexes (5.35 to 2.20 for men, 3.15 to 1.77 for women). Patients aged 80 years and older had the highest incidence rate at 40.2, and 86.3 % of CUPs occurred in those 50 years of age or older. The cases of retroperitoneum and peritoneum sites increased over time. Cases diagnosed by microscopic methods and death certification only were 62.3 % and 7.9 %, respectively. The malignant neoplasm of the retroperitoneum and peritoneum and unknown primary site had the highest and lowest survival rates, respectively. The 5-year relative survival rate increased over time from 14.2 % (1999–2002) to 27.3 % (2013–2017).ConclusionsOur analysis of data from the Korea Central Cancer Registry found decreasing rates of CUP, although with consistent disparities by patient age and sex. Advancements in diagnostic technology may be decreasing the number of CUP diagnoses. Expanding the amount of information recorded in the registry may further improve diagnostic accuracy.     

Clinical profile and outcomes of semi-permanent pacing in a tertiary care institute in southern India

BackgroundSemi-permanent pacing (SPP) includes the placement of a permanent lead through the internal jugular vein and connection to a pulse generator on the skin outside the venous access site.AimTo evaluate the clinical profile and outcomes of semi-permanent pacing in a tertiary care institute in Southern India.MethodsThis is a retrospective observational study. All patients admitted and requiring management with semi-permanent pacing from January 2017 to June 2020 were included.ResultsFrom January 2017 to June 2020, 20 patients underwent semi-permanent pacing (SPP) with a median age of 54 (21–74) years. Males comprised a majority of the patients (55%). Hypertension was noted in 50% of patients and 30% were diabetic. The right internal jugular vein was the most common access in 95% of patients. The most common indication for semi-permanent pacing was pocket site infection in 30% of patients. There were no procedural complications. The median duration on SPP was 7 (5–14) days and the median duration of hospital stay was 13 (8–21) days. Permanent pacemaker implantation was done in 55% of patients. Mortality in our study group was 15% with 10% dying due to cardiogenic shock (post resuscitated cardiac arrest) and 5% dying due to non-cardiac cause (Epidural hematoma).ConclusionIn our study, semi-permanent pacing was noted to be a safe procedure and was more commonly indicated in emergent conditions with complete heart block secondary to underlying reversible causes and in the management of pocket site infection.     

Epidemiological trends of neuroendocrine tumours over three decades in Queensland,Australia

IntroductionWhile neuroendocrine tumours (NETs) account for only a small proportion of cancer diagnoses, incidence has been rising over time. We examined incidence, mortality and survival over three decades in a large population-based registry study.MethodsThis retrospective study included all cases (n = 4580) of NETs diagnosed from 1986 to 2015 in Queensland, Australia. We examined directly age-standardised incidence and mortality rates. The impact on overall survival according to demographic factors and primary site was modelled using multivariable Cox proportional hazards regression (HR). Cause-specific and relative survival were estimated using the Kaplan-Meier survival function.ResultsAnnual incidence increased from 2.0 in 1986 to 6.3 per 100,000 in 2015, while mortality remained stable. The most common primary site was appendix followed by lung, small intestine and rectum. Rectal, stomach, appendiceal and pancreatic NETs had the greatest rate increase, while lung NETs decreased over the same period. Five-year cause-specific survival improved from 69.4% during 1986–1995 to 92.6% from 2006 to 2015. Survival was highest for appendiceal and rectal NETs and lowest for pancreas and unknown primary sites. The risk of dying within five years of diagnosis was about 40% higher for males (HR = 1.41, 95%CI 1.20–1.65) and significantly higher for patients aged over 40 years compared to younger patients (p < 0.001).ConclusionThis study, including 30 years of data, found significantly increasing rates of NETs and confirms results from elsewhere. Increasing survival over time in this study, likely reflects increased awareness, improvements in diagnostic imaging, greater use of endoscopy and colonoscopy, and the development of new therapies.     

Efficacy and safety of leadless pacemaker: A systematic review,pooled analysis and meta-analysis

BackgroundLeadless pacemakers have been designed as an alternative to transvenous systems which avoid some of the complications associated with transvenous devices. We aim to perform a systematic review of the literature to report the safety and efficacy findings of leadless pacemakers.MethodsWe searched MEDLINE and EMBASE to identify studies reporting the safety, efficacy and outcomes of patients implanted with a leadless pacemaker. The pooled rate of adverse events was determined and random-effects meta-analysis was performed to compare rates of adverse outcomes for leadless compared to transvenous pacemakers.ResultsA total of 18 studies were included with 2496 patients implanted with a leadless pacemaker and success rates range between 95.5 and 100%. The device or procedure related death rate was 0.3% while any complication and pericardial tamponade occurred in 3.1% and 1.4% of patients, respectively. Other complications such as pericardial effusion, device dislodgement, device revision, device malfunction, access site complications and infection occurred in less than 1% of patients. Meta-analysis of four studies suggests that there was no difference in hematoma (RR 0.67 95%CI 0.21–2.18, 3 studies), pericardial effusion (RR 0.59 95%CI 0.15–2.25, 3 studies), device dislocation (RR 0.33 95%CI 0.06–1.74, 3 studies), any complication (RR 0.44 95%CI 0.17–1.09, 4 studies) and death (RR 0.45 95%CI 0.15–1.35, 2 studies) comparing patients who received leadless and transvenous pacemakers.ConclusionLeadless pacemakers are safe and effective for patients who have an indication for single chamber ventricular pacing and the findings appear to be comparable to transvenous pacemakers.     

Does elevated wall tension cause aortic aneurysm rupture? Investigation using a subject-specific heterogeneous model

ObjectiveTo investigate whether peak wall tension in abdominal aortic aneurysm occurs at the site of rupture to test for a causative relationship.MethodsFour ruptured and nine unruptured AAA were harvested whole from cadavers, followed by regional measurements of wall thickness, elastic parameters and failure tension. Finite element models were developed with subject-specific load-free AAA morphology and heterogeneous properties interpolated using a geodesic distance weighted approach from the measurements. The wall tension under uniform pressure and tension to failure tension ratio as an index of susceptibility to rupture were computed. As a secondary aim, the peak wall tension using this heterogeneous model approach was compared to the traditional homogeneous model approach in order to evaluate the reliability of the latter.ResultsThe average peak wall tension in the ruptured group was 43% higher than in the unruptured group without statistical significance even though it was 54% larger in diameter. The site of peak wall tension was in the vicinity of the site of rupture in two ruptured AAA. The peak tension did not breach failure tension at the rupture site in any of the AAA. The traditional population-wide homogeneous model approach overestimated peak wall tension by just 3% compared to the subject-specific heterogeneous model approach.ConclusionWe failed to find adequate evidence of a causative relationship between peak wall tension and AAA rupture. The findings are not conclusive owing to study limitations such as ignoring intraluminal thrombus, sparse distribution of specimens procured and small study population.     

超声引导下Mammotome微创旋切术治疗乳腺良性肿块

目的:研究超声引导下Mammotome微创旋切术对乳腺良性肿块的治疗价值。方法:回顾性分析2014年9月至2016年9月在本院就诊的BI-RADS分级为2~3级的387例乳腺良性肿块患者,运用Mammotome对729处乳腺病灶行微创旋切术,分析术后病理、并发症、随访半年后的治疗结果。结果:387例患者的729处乳腺病灶均获一次性成功切除。病理示均为良性病灶,其中32个合并不典型增生。术后出现局部血肿共11例(2.8%),皮下瘀斑共16例(4.1%),所有患者均未发生感染及气胸等严重并发症。术后6个月18个在病灶原部位发现肿块;手术无残留率为97.5%。结论:应用超声引导下Mammotome微创旋切术治疗乳腺良性肿块临床可行。     

Structurally Altered Substrates for DNA Topoisomerase. I. Effects of Inclusion of a Single 3′-Deoxynucleotide Within the Scissile Strand†

Abstract

A partial DNA duplex containing a high efficiency topoisomerase I cleavage site was substituted singly at each of three sites with 3′-deoxyadenosine. Depending on the site of substitution, the facility of the topoisomerase I-mediated cleavage or ligation reactions was altered. Inclusion of the modified nucleoside at the 5′-end of the acceptor oligonucleotide diminished the rate of religation following substrate cleavage by the enzyme.