HIIphot: Automated Photometry of HII Regions Applied to M51

We have developed a robust, automated method, hereafter designated HIIphot, which enables accurate photometric characterization of HII regions while permitting genuine adaptivity to irregular source morphology. HIIphot utilizes object-recognition techniques to make a first guess at the shapes of all sources then allows for departure from such idealized ``seeds'' through an iterative growing procedure. Photometric corrections for spatially coincident diffuse emission are derived from a low-order surface fit to the background after exclusion of all detected sources. We present results for the well-studied, nearby spiral M51 in which 1229 HII regions are detected above the 5-sigma level. A simple, weighted power-law fit to the measured H-alpha luminosity function (HII LF) above log L_H-alpha = 37.6 gives alpha = -1.75+/-0.06, despite a conspicuous break in the HII LF observed near L_H-alpha = 10^38.9. Our best- fit slope is marginally steeper than measured by Rand (1992), perhaps reflecting our increased sensitivity at low luminosities and to notably diffuse objects. HII regions located in interarm gaps are preferentially less luminous than counterparts which constitute M51's grand-design spiral arms and are best fit with a power-law slope of alpha = -1.96+/-0.15. We assign arm/interarm status for HII regions based upon the varying surface brightness of diffuse emission as a function of position throughout the image. Using our measurement of the integrated flux contributed by resolved HII regions in M51, we estimate the diffuse fraction to be approximately 0.45 -- in agreement with the determination of Greenawalt et al. (1998). Automated processing of degraded datasets is undertaken to gauge systematic effects associated with limiting spatial resolution and sensitivity.Comment: 41 pages, 14 figures, Postscript version with high-resolution figures at ftp://ftp.aoc.nrao.edu/staff/dthilker/preprint

Deep sternal wound infection after open heart surgery: current treatment insights. A retrospective study of 36 cases

The aim of this study was to retrospectively evaluate the results of reconstructing infected post-sternotomy wounds, with either sternal plating and/or pectoralis major flap transposition or pedicled omentoplasty after previous vacuum-assisted closure (VAC) therapy. Between January 2005 and December 2010, 36 patients, suffering from deep sternal wound infection (DSWI) after coronary artery bypass grafting procedure, received (plastic) reconstructive surgery. All patients, treated in the Maastricht University Medical Centre (Departments of Plastic Surgery and Cardiothoracic Surgery), were selected for this study. For 22 patients, sternal refixation and reconstruction were obtained by sternal internal plate fixation combined with bilateral pectoralis major advancement flap. In 11 patients, a pedicled omentoplasty was performed, with or without split-skin graft and additional VAC therapy. Three patients only received a pectoralis plasty. We evaluated preoperative characteristics and post-operative course. Twenty-four patients (66.7%) had an uneventful post-operative course. Complications in the other patients included wound dehiscence, herniation of the donor site and infection of sternal plating material. Average sternal wound healing after sternal plating plus pectoralis plasty, pectoralis plasty and omentoplasty respectively accounted 7.7, 8.0 and 11.6 weeks. From our experience, we recommend VAC therapy plus delayed sternal plating and additional bilateral pectoralis major flap advancement as first repair option in case of DSWI. However, individual clinical conditions need to be taken into account when making a decision between the different available reconstructive options. Omentoplasty should be reserved for cases in which the sternum has recurrently fallen open after previous sternal plate refixation, or for cases in which the sternum defect is too extended

Las espigas de aparición tardía en trigo : condiciones que determinan su ocurrencia y consecuencias sobre el rendimiento

p.35-45Se evaluó la aparición tardía de espigas en el cultivo de trigo, para la sub región triguera II N argentina, discutiéndose las consecuencias sobre el rendimiento y sus componentes. A estos efectos se utilizaron resultados de ensayos multi locales (5 sitios) durante dos campañas (1982-1983) donde se varió la dosis y el momento de aplicación de nitrógeno. Se demostró la incidencia de la disponibilidad y el momento de aplicación del nitrógeno sobre la magnitud de este grupo de espigas, en condiciones de sequía en encañazón seguidas por importantes lluvias en pre floración, pudiendo estas representar el 40 por ciento de las espigas totales a cosecha. La contribución de estas espigas sobre el rendimiento se redujo a cerca de la mitad de la ejercida sobre el número de granos por metro cuadrado. Esto se debió a que los pesos de milgranos de este grupo de espigas fueron afectados por altas temperaturas durante su periodo de llenado, retrasando respecto al primer grupo. Se destaca el interés para el agrónomo de cuantificar este fenómeno para mejorar las estimaciones de rendimientos y los estudios de fechas de adición de nitrógeno

Perioperative Hyperspectral Imaging to Assess Mastectomy Skin Flap and DIEP Flap Perfusion in Immediate Autologous Breast Reconstruction: A Pilot Study.

Mastectomy skin flap necrosis (MSFN) and partial DIEP (deep inferior epigastric artery perforator) flap loss represent two frequently reported complications in immediate autologous breast reconstruction. These complications could be prevented when areas of insufficient tissue perfusion are detected intraoperatively. Hyperspectral imaging (HSI) is a relatively novel, non-invasive imaging technique, which could be used to objectively assess tissue perfusion through analysis of tissue oxygenation patterns (StO2%), near-infrared (NIR%), tissue hemoglobin (THI%), and tissue water (TWI%) perfusion indices. This prospective clinical pilot study aimed to evaluate the efficacy of HSI for tissue perfusion assessment and to identify a cut-off value for flap necrosis. Ten patients with a mean age of 55.4 years underwent immediate unilateral autologous breast reconstruction. Prior, during and up to 72 h after surgery, a total of 19 hyperspectral images per patient were acquired. MSFN was observed in 3 out of 10 patients. No DIEP flap necrosis was observed. In all MSFN cases, an increased THI% and decreased StO2%, NIR%, and TWI% were observed when compared to the vital group. StO2% was found to be the most sensitive parameter to detect MSFN with a statistically significant lower mean StO2% (51% in the vital group versus 32% in the necrosis group, p < 0.0001) and a cut-off value of 36.29% for flap necrosis. HSI has the potential to accurately assess mastectomy skin flap perfusion and discriminate between vital and necrotic skin flap during the early postoperative period prior to clinical observation. Although the results should be confirmed in future studies, including DIEP flap necrosis specifically, these findings suggest that HSI can aid clinicians in postoperative mastectomy skin flap and DIEP flap monitoring

Substantial chest-wall deformity following tissue expansion after radiotherapy

We present the case of a 54-year-old woman who underwent a two-stage breast reconstruction with a tissue expander after sustaining a lumpectomy and local radiotherapy for breast cancer. During expansion, the woman developed an abnormal concave deformity of the chest wall. Although respiratory or aesthetic consequences were expected, our patient reported only pain and was satisfied with the end result. Osteoporosis or local recurrence was excluded as predisposing factors, and radiotherapy was considered to be the causal factor in our patient. On the basis of this finding, we advise surgeons to take the risk of chest-wall deformity into consideration when planning a reconstruction with tissue expanders, especially in patients with a history of radiotherapy, and we recommend an alternative reconstructive method in this group of patients

Double sampling of a faecal immunochemical test is not superior to single sampling for detection of colorectal neoplasia: a colonoscopy controlled prospective cohort study

<p>Abstract</p> <p>Background</p> <p>A single sampled faecal immunochemical test (FIT) has moderate sensitivity for colorectal cancer and advanced adenomas. Repeated FIT sampling could improve test sensitivity. The aim of the present study is to determine whether any of three different strategies of double FIT sampling has a better combination of sensitivity and specificity than single FIT sampling.</p> <p>Methods</p> <p>Test performance of single FIT sampling in subjects scheduled for colonoscopy was compared to double FIT sampling intra-individually. Test positivity of double FIT sampling was evaluated in three different ways: 1) "one of two FITs+" when at least one out of two measurements exceeded the cut-off value, 2) "two of two FITs+" when both measurements exceeded the cut-off value, 3) "mean of two FITs+" when the geometric mean of two FITs exceeded the cut-off value. Receiver operator curves were calculated and sensitivity of single and the three strategies of double FIT sampling were compared at a fixed level of specificity.</p> <p>Results</p> <p>In 124 of 1096 subjects, screen relevant neoplasia (SRN) were found (i.e. early stage CRC or advanced adenomas). At any cut-off, "two of two FITs+" resulted in the lowest and "one of two FITs+" in the highest sensitivity for SRN (range 35-44% and 42%-54% respectively). ROC's of double FIT sampling were similar to single FIT sampling. At specificities of 85/90/95%, sensitivity of any double FIT sampling strategy did not differ significantly from single FIT (p-values 0.07-1).</p> <p>Conclusion</p> <p>At any cut off, "one of two FITs+" is the most sensitive double FIT sampling strategy. However, at a given specificity level, sensitivity of any double FIT sampling strategy for SRN is comparable to single FIT sampling at a different cut-off value. None of the double FIT strategies has a superior combination of sensitivity and specificity over single FIT.</p

Fluid hydration to prevent post-ERCP pancreatitis in average- to high-risk patients receiving prophylactic rectal NSAIDs (FLUYT trial): Study protocol for a randomized controlled trial

Background: Post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP) is the most common complication of ERCP and may run a severe course. Evidence suggests that vigorous periprocedural hydration can prevent PEP, but studies to date have significant methodological drawbacks. Importantly, evidence for its added value in patients already receiving prophylactic rectal non-steroidal anti-inflammatory drugs (NSAIDs) is lacking and the cost-effectiveness of the approach has not been investigated. We hypothesize that combination therapy of rectal NSAIDs and periprocedural hydration would significantly lower the incidence of post-ERCP pancreatitis compared to rectal NSAIDs alone in moderate- to high-risk patients undergoing ERCP. Methods: The FLUYT trial is a multicenter, parallel group, open label, superiority randomized controlled trial. A total of 826 moderate- to high-risk patients undergoing ERCP that receive prophylactic rectal NSAIDs will be randomized to a control group (no fluids or normal saline with a maximum of 1.5 mL/kg/h and 3 L/24 h) or intervention group (lactated Ringer's solution with 20 mL/kg over 60 min at start of ERCP, followed by 3 mL/kg/h for 8 h thereafter). The primary endpoint is the incidence of post-ERCP pancreatitis. Secondary endpoints include PEP severity, hydration-related complications, and cost-effectiveness. Discussion: The FLUYT trial design, including hydration schedule, fluid type, and sample size, maximize its power of identifying a potential difference in post-ERCP pancreatitis incidence in patients receiving prophylactic rectal NSAIDs

Does delay in diagnosing colorectal cancer in symptomatic patients affect tumor stage and survival? A population-based observational study

<p>Abstract</p> <p>Background</p> <p>Diagnosing colorectal cancer (CRC) at an early stage improves survival. To what extent any delay affects outcome once patients are symptomatic is still unclear.</p> <p>Our objectives were to evaluate the association between diagnostic delay and survival in symptomatic patients with early stage CRC and late stage CRC.</p> <p>Methods</p> <p>Prospective population-based observational study evaluating daily clinical practice in Northern Holland. Diagnostic delay was determined through questionnaire-interviews. Dukes' stage was classified into two groups: early stage (Dukes A or B) and late stage (Dukes C or D) cancer. Patients were followed up for 3.5 years after diagnosis.</p> <p>Results</p> <p>In total, 272 patients were available for analysis. Early stage CRC was present in 136 patients while 136 patients had late stage CRC. The mean total diagnostic delay (SE) was 31 (1.5) weeks in all CRC patients. No significant difference was observed in the mean total diagnostic delay in early versus late stage CRC (<it>p </it>= 0.27).</p> <p>In early stage CRC, no difference in survival was observed between patients with total diagnostic delay shorter and longer than the median (Kaplan-Meier, log-rank <it>p </it>= 0.93).</p> <p>In late stage CRC, patients with a diagnostic delay shorter than the median had a shorter survival than patients with a diagnostic delay longer than the median (log-rank <it>p </it>= 0.01). In the multivariate Cox regression model with survival as dependent variable and median delay, age, open access endoscopy, number and type of symptoms as independent variables, the odd's ratio for survival in patients with long delay (>median) versus short delay (≤median) was 1.8 (95% confidence interval (CI) 1.1 to 3.0; <it>p </it>= 0.01). Tumor-site was not associated with patient survival. When separating late stage CRC in Dukes C and Dukes D tumors, a shorter delay was associated with a shorter survival in Dukes D tumors only and not in Dukes C tumors.</p> <p>Conclusion</p> <p>In symptomatic CRC patients, a longer diagnostic and therapeutic delay in routine clinical practice was not associated with an adverse effect on survival. The time to CRC diagnosis and initiation of treatment did not differ between early stage and late stage colorectal cancer.</p