169,741 research outputs found
Factors associated with metachronous metastases and survival in locally advanced and recurrent rectal cancer
No full textBackground
Better understanding of the impact of metachronous metastases in locally advanced and recurrent rectal cancer may improve decision‐making. The aim of this study was to investigate factors influencing metachronous metastasis and its impact on survival in patients who have a beyond total mesorectal excision (bTME) operation.
Methods
This was a retrospective study of consecutive patients who had bTME surgery for locally advanced and recurrent rectal cancer at a tertiary referral centre between January 2006 and December 2016. The primary outcome was overall survival. Cox proportional hazards regression analyses were performed. The influence of metachronous metastases on survival was investigated.
Results
Of 220 included patients, 171 were treated for locally advanced primary tumours and 49 for recurrent rectal cancer. Some 90·0 per cent had a complete resection with negative margins. Median follow‐up was 26·0 (range 1·5–119·6) months. The 5‐year overall survival rate was 71·1 per cent. Local recurrence and metachronous metastasis rates were 11·8 and 22·2 per cent respectively. Patients with metachronous metastases had a worse overall survival than patients without metastases (median 52·9 months versus estimated mean 109·4 months respectively; hazard ratio (HR) 6·73, 95 per cent c.i. 3·23 to 14·00). Advancing pT category (HR 2·01, 1·35 to 2·98), pN category (HR 2·43, 1·65 to 3·59), vascular invasion (HR 2·20, 1·22 to 3·97) and increasing numbers of positive lymph nodes (HR 1·19, 1·07 to 1·16) increased the risk of metachronous metastasis. Nine of 17 patients (53 per cent) with curatively treated synchronous metastases at presentation developed metachronous metastases, compared with 40 of 203 (19·7 per cent) without synchronous metastases (P = 0·002). Corresponding median length of disease‐free survival was 17·5 versus 90·8 months (P < 0·001).
Conclusion
As metachronous metastases impact negatively on survival after bTME surgery, factors associated with metachronous metastases may serve as selection tools when determining suitability for treatment with curative intent
A systematic review and meta-analysis comparing adverse events and functional outcomes of different pouch designs after restorative proctocolectomy
No full textAim There is no consensus as to which ileoanal pouch design provides better outcomes after restorative proctocolectomy. This study compares different pouch designs. Method A systematic review of the literature was performed. A random effects meta-analytical model was used to compare adverse events and functional outcome. Results Thirty comparative studies comparing J, W, S and K pouch designs were included. No significant differences were identified between the different pouch designs with regard to anastomotic dehiscence, anastomotic stricture, pelvic sepsis, wound infection, pouch fistula, pouch ischaemia, perioperative haemorrhage, small bowel obstruction, pouchitis and sexual dysfunction. The W and K designs resulted in fewer cases of pouch failure compared with the J and S designs. J pouch construction resulted in a smaller maximum pouch volume compared with W and K pouches. Stool frequency per 24 h and during daytime was higher following a J pouch than W, S or K constructions. The J design resulted in increased faecal urgency and seepage during daytime compared with the K design. The use of protective pads during daytime and night-time was greater with a J pouch compared to S or K. The use of antidiarrhoeal medication was greater after a J reservoir than a W reservoir. Difficulty in pouch evacuation requiring intubation was higher with an S pouch than with W or J pouches. Conclusion Despite its ease of construction and comparable complication rates, the J pouch is associated with higher pouch failure rates and worse function. Patient characteristics, technical factors and surgical expertise should be considered when choosing pouch design
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Abdominal versus perineal approach for external rectal prolapse: systematic review with meta-analysis
No full textBACKGROUND: External rectal prolapse (ERP) is a debilitating condition in which surgery plays an important role. The aim of this study was to evaluate the outcomes of abdominal approaches (AA) and perineal approaches (PA) to ERP. METHODS: This was a PRISMA-compliant systematic review with meta-analysis. Studies published between 1990 and 2021 were retrieved. The primary endpoint was recurrence at the last available follow-up. Secondary endpoints included factors associated with recurrence and function. All studies were assessed for bias using the Newcastle-Ottawa Scale and Cochrane tool. RESULTS: Fifteen studies involving 1611 patients (AA = 817; PA = 794) treated for ERP were included, three of which were randomized controlled trials (RCTs; 114 patients (AA = 54; PA = 60)). Duration of follow-up ranged from 12 to 82 months. Recurrence in non-randomized studies was 7.7 per cent in AA versus 20.1 per cent in PA (odds ratio (OR) 0.29, 95 per cent confidence interval (c.i.) 0.17 to 0.50; P < 0.001, I2 = 45 per cent). In RCTs, there was no significant difference (9.8 per cent versus 16.3 per cent, AA versus PA (OR 0.82, 95 per cent c.i. 0.29 to 2.37; P = 0.72, I2 = 0.0 per cent)). Age at surgery and duration of follow-up were risk factors for recurrence. Following AA, the recurrence rates were 10.1 per cent and 6.2 per cent in patients aged 65 years and older and less than 65 years of age, respectively (effect size [e.s.] 7.7, 95 per cent c.i. 4.5 to 11.5). Following PA, rates were 27 per cent and 16.3 per cent (e.s. 20.1, 95 per cent c.i. 13 to 28.2). Extending follow-up to at least 40 months increased the likelihood of recurrence. The median duration of hospital stay was 4.9 days after PA versus 7.2 days after AA. Overall, incontinence was less likely after AA (OR 0.32), but constipation occurred more frequently (OR 1.68). Most studies were retrospective, and several outcomes from RCTs were not consistent with those observed in non-RCTs. CONCLUSION: The overall risk of recurrence of ERP appears to be higher with PA versus AA. Incontinence is less frequent after AA but at the cost of increased constipation. Age at surgery and duration of follow-up are associated with increased risk of recurrence, which warrants adequate reporting of future studies on this topic
Mitomycin C in highly myopic eyes - Author reply
No full textOphthalmology. 2005 Feb;112(2):208-18; discussion 219.
Mitomycin C modulation of corneal wound healing after photorefractive keratectomy in highly myopic eyes.
Gambato C, Ghirlando A, Moretto E, Busato F, Midena E.
SourceRefractive Surgery Service and Antimetabolite Therapy Research Unit, Department of Ophthalmology, University of Padova, Padova, Italy.
Abstract
PURPOSE: To evaluate the role of topical mitomycin C in corneal wound healing (CWH) after photorefractive keratectomy (PRK) in highly myopic eyes.
DESIGN: Prospective, double-masked, randomized clinical trial.
PARTICIPANTS: Seventy-two eyes of 36 patients affected by high (>7 diopters) myopia.
METHODS: In each patient, one eye was randomly assigned to PRK with intraoperative topical 0.02% mitomycin C application, and the fellow eye was treated with a placebo. Postoperatively, mitomycin C-treated eyes received artificial tears (3 times daily, tapered in 3 months), whereas the fellow eye was treated with fluorometholone sodium 2% and artificial tears (3 times daily, tapered in 3 months).
MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), contrast sensitivity, manifest refraction, and biomicroscopy. Contrast sensitivity was determined using the Pelli-Robson chart. Corneal confocal microscopy documented CWH.
RESULTS: Mean follow-up was 18 months (range, 12-36). No side effects or toxic effects were documented. At 12-month follow-up examination, UCVAs (logarithm of the minimum angle of resolution) were 0.4+/-0.48 and 0.5+/-0.53 (P = .03) in mitomycin C-treated eyes and corticosteroid-treated eyes, respectively. At 1 year, corneal haze developed in 20% of corticosteroid-treated eyes, versus 0% of mitomycin C-treated eyes. At 12, 24, and 36 months, corneal confocal microscopy showed activated keratocytes and extracellular matrix significantly more evident in untreated eyes (Ps = 0.004, 0.024, and 0.046, respectively).
CONCLUSION: Topical intraoperative application of 0.02% mitomycin C can reduce haze formation in highly myopic eyes undergoing PRK.
Comment in
Ophthalmology. 2006 Feb;113(2):357; author reply 357-8
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
A systematic review and network meta-analysis comparing energy devices used in colorectal surgery
No full textBackground The aim of this study was to compare energy devices used for intraoperative hemostasis during colorectal surgery. Methods A systematic literature review and Bayesian network meta-analysis performed. MEDLINE, EMBASE, Science Citation Index Expanded, and Cochrane were searched from inception to August 11th 2021. Intraoperative outcomes were operative blood loss, operative time, conversion to open, conversion to another energy source. Postoperative outcomes were mortality, overall complications, minor complications and major complications, wound complications, postoperative ileus, anastomotic leak, time to first defecation, day 1 and 3 drainage volume, duration of hospital stay. Results Seven randomized controlled trials (RCTs) were included, reporting on 680 participants, comparing conventional hemostasis, LigaSure (TM), Thunderbeat(R) and Harmonic(R). Harmonic(R) had fewer overall complications compared to conventional hemostasis. Operative blood loss was less with LigaSure (TM) (mean difference [MD] = 24.1 ml; 95% confidence interval [CI] - 46.54 to - 1.58 ml) or Harmonic(R) (MD = 24.6 ml; 95% CI - 42.4 to - 6.7 ml) compared to conventional techniques. Conventional hemostasis ranked worst for operative blood loss with high probability (p = 0.98). LigaSure (TM), Harmonic(R) or Thunderbeat(R) resulted in a significantly shorter mean operative time by 42.8 min (95% CI - 53.9 to - 31.5 min), 28.3 min (95% CI - 33.6 to - 22.6 min) and 26.1 min (95% CI - 46 to - 6 min), respectively compared to conventional electrosurgery. LigaSure (TM) resulted in a significantly shorter mean operative time than Harmonic(R) by 14.5 min (95% CI 1.9-27 min) and ranked first for operative time with high probability (p = 0.97). LigaSure (TM) and Harmonic(R) resulted in a significantly shorter mean duration of hospital stay compared to conventional electrosurgery of 1.3 days (95% CI - 2.2 to - 0.4) and 0.5 days (95% CI - 1 to - 0.1), respectively. LigaSure (TM) ranked as best for hospital stay with high probability (p = 0.97). Conventional hemostasis was associated with more wound complications than Harmonic(R) (odds ratio [OR] = 0.27; CI 0.08-0.92). Harmonic(R) ranked best with highest probability (p = 0.99) for wound complications. No significant differences between energy devices were identified for the remaining outcomes. Conclusions LigaSure (TM), Thunderbeat(R) and Harmonic(R) may be advantageous for reducing operative blood loss, operative time, overall complications, wound complications, and duration of hospital stay compared to conventional techniques. The energy devices result in comparable perioperative outcomes and no device is superior overall. However, included RCTs were limited in number and size, and data were not available to compare all energy devices for all outcomes of interest
The role of adjuvant chemotherapy on survival and recurrence after curative rectal cancer surgery on patients who are histologically node negative after neoadjuvant chemoradiotherapy.
No full textAIM: The aim of this study is to evaluate whether adjuvant chemotherapy will affect recurrence rates, disease free and overall survival in patients with rectal adenocarcinoma who were staged with MRI node positive disease (mrN+) preoperatively and underwent neoadjuvant chemoradiotherapy with curative rectal cancer surgery and their pathological staging was negative for nodal disease (ypN0). There is no consensus on the role of adjuvant chemotherapy in these patients. METHOD: Patients who received neoadjuvant chemoradiotherapy and underwent curative rectal cancer surgery for rectal adenocarcinoma staged as [mrTxN+M0] on MRI staging and on pathological staging were found to be [ypTxN0M0] were retrospectively identified from 01/2008-12/2012 from two tertiary referral centers (Royal Marsden Hospital and Saint-Andre Hospital). RESULTS: 163 patients were recruited and after propensity matching at a ratio of 2:1 n=80 patients were divided into adjuvant (n=28) and no adjuvant treatment (n=52) respectively. A comparison of adjuvant chemotherapy vs no adjuvant therapy showed that the mean overall survival was 2.67 vs 3.60 years (p=0.42), disease free survival was 2.27 vs 3.32 years (p=0.14). CONCLUSION: This study found no significant difference in survival or disease recurrence between patients who received adjuvant chemotherapy and patients who did not. There is no clear evidence to support or dismiss the use of adjuvant chemotherapy for patients who have been node positive on pre-operative MRI and node negative on histopathological staging. Further multicenter prospective randomised trials are needed to identify the appropriate treatment regime for this group of patients
A Multi-Language Comparison of Influences on Author Verification using Character N-Grams
No full textWe create a new multi-language corpus for author verification based on Wikipedia talkpages, and evaluate the influence that differences in topic and time have on character n-gram author profiles. Topic alignment between two texts is found to increase author verification precision, and an authors writing style is found to change over time, but not more significantly after 3 years than after 1 year.Information ArchitectureWISElectrical Engineering, Mathematics and Computer Scienc
A 0.12mm<sup>2</sup> Wien-Bridge Temperature Sensor with 0.1°C (3σ) Inaccuracy from -40°C to 180°C
No full text Resistor-based temperature sensors can achieve much higher resolution and energy efficiency than conventional BJT-based sensors [1], but they typically occupy more area (> 0.25 mm 2 ) and have lower operating temperatures (le 125 {circ} {C}) [2]-[4]. This work describes a 0.12mm 2 resistor-based sensor that uses a Wien-bridge (WB) filter to achieve 0.1 {circ} {C} (3 sigma) inaccuracy from - 40 {circ} {C} to 180 {circ} {C}. Compared to a state-of-the-art WB sensor [4], it occupies 6 × less area and achieves comparable relative accuracy over a 76% wider operating range. Session 10.3 Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic
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