Classification Regression Tree Analysis Research Articles

Multiplexed serum biomarkers to discriminate nonviable and ectopic pregnancy

ObjectiveThe use of multiplexed biomarkers may improve the diagnosis of normal and abnormal early pregnancies. In this study we assessed 24 markers with multiple machine learning-based methodologies to evaluate combinations of top candidates to develop a multiplexed prediction model for identification of 1) viability and 2) location of an early pregnancy. DesignA nested case-control design evaluating the predictive ability and discrimination of biomarkers in patients at risk of early pregnancy failure in the first trimester to classify viability and location Subjects218 individuals with a symptomatic (pain and/or bleeding) early pregnancy: 75 with an ongoing intrauterine gestation, 68 ectopic pregnancies, and 75 miscarriages. InterventionsSerum values of 24 biomarkers were assessed in the same patients. Multiple machine learning-based methodologies to evaluate combinations of these top candidates to develop a multiplexed prediction model for identification of 1) a nonviable pregnancy (ongoing intrauterine pregnancy vs miscarriage or ectopic pregnancy) and 2) an ectopic pregnancy (ectopic pregnancy vs ongoing intrauterine pregnancy or miscarriage). Main Outcome MeasuresThe predicted classification by each model was compared to actual diagnosis and sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), conclusive classification, and accuracy were calculated. ResultsModels using classification regression tree analysis using three markers (PSG3, CG-Alpha and PAPPA) were able to predict a maximum sensitivity 93.3%, a maximum specificity 98.6%. The model with the highest accuracy was 97.4% (with 70.2% receiving classification). Models using an overlapping group of three markers (sFLT, PSG3 and TFP12) achieved a maximum sensitivity of 98.5%. and a maximum specificity of 95.3%. The model with the highest accuracy was 94.4% (with 65.6% receiving classification). When the models were used simultaneously the conclusive classification increased to 72.7% with an accuracy 95.9%. The predictive ability of the biomarkers random forest produced similar test characteristics when using 11 predictive markers. ConclusionWe have demonstrated a pool of biomarkers from divergent biological pathways that can be used to classify individuals with potential early pregnancy loss. The biomarkers CG-Alpha, PAPPA and PSG3 can be used to predict viability and sFLT, TPFI2 and PSG3 can be used to predict pregnancy location.

Debt as a Source of Financial Energy of the Farm—What Causes the Use of External Capital in Financing Agricultural Activity? A Model Approach

The aim of this study was to identify and assess the factors influencing the increase in the financial energy of a farm through the use of external capital, taking into account the farmer’s and farm characteristics. For its implementation, a logistic regression model and a classification-regression tree analysis (CRT) were used. The study was conducted on a group of farms in Central Pomerania (Poland) participating in the system of collecting and using data from farms (Farm Accountancy Data Network—FADN). Data on 348 farms were used for the analyses, obtained through a survey conducted in 2020 with the use of a questionnaire. Based on the analysis of the research results presented in the literature to date, it was established that the use of external capital in a farm as a factor increasing financial energy is determined, on the one hand, by the socio-demographic characteristics of the farmer and the characteristics of the farm, and on the other hand, by the availability of external financing sources. Factors relating to the first of these aspects were taken into account in the study. Using the logistic regression model, it was established that the propensity to indebtedness of farms is promoted by the following factors: gender of the head of the household (male, GEND), younger age of the head of the household (AGE), having a successor who will take over the farm in the future (SUC), higher value of generated production (PROD_VALUE), larger farm area (AREA) and multi-directional production of the farm (production diversification), as opposed to targeting plant or animal production only (farm specialization—SPEC). The results of the analysis carried out with the use of classification and regression trees (CRT) showed that the key factors influencing the use of outside capital as a source of financial energy in the agricultural production process are, first of all, features relating to an agricultural holding: the value of generated production (PROD_VALUE), agricultural area (AREA) and production direction (SPEC). The age of the farm manager (AGE) turned out to be of key importance among the farmer’s features favoring the tendency to take debt in order to finance agricultural activity.

Amplification of Antimicrobial Resistance in Gut Flora of Patients Treated with Ceftriaxone.

Although antibacterial therapy has an impact on human intestinal flora and the emergence of resistant bacteria, its role in the amplification of antimicrobial resistance and the quantitative exposure-effect relationship is not clear. An observational prospective study was conducted to determine whether and how ceftriaxone exposure is related to amplification of resistance in non-intensive care unit (non-ICU) patients. Serial stool samples from 122 extended-spectrum β-lactamase-positive (ESBL+) hospitalized patients were analyzed by quantitative real-time PCR to quantify the resistant gene blaCTX-M Drug exposure was calculated for each patient by using a population pharmacokinetic model. Multi- and univariate regression and classification regression tree (CART) analyses were used to explore relationships between measures of exposure and amplification of blaCTX-M genes. Amplification of blaCTX-M was observed in 0% (0/11) of patients with no treatment and 33% (20/61) of patients treated with ceftriaxone. Stepwise regression analysis showed a significant association between amplification of blaCTX-M and the plasma area under the concentration-time curve from 0 to 24 h for the unbound fraction of the drug (fAUC0-24), the maximum concentration of drug in serum for the unbound fraction of the drug (fCmax), and the duration of ceftriaxone therapy. Using CART analysis, amplification of blaCTX-M was observed in 11/16 (69%) patients treated for >14 days and in 9/40 (23%) patients treated for ≤14 days (P = 0.0019). In the latter group, amplification was observed in 5/7 (71%) patients with an fAUC0-24 of ≥222 mg · h/liter and in 4/33 (12%) patients with lower drug exposures (P = 0.0033). A similar association was found for an fCmax of ≥30 mg/liter (63% versus 13%, P = 0.0079). A significant association was found between the amplification of blaCTX-M resistance genes and exposure to ceftriaxone. Both duration of treatment and degree of ceftriaxone exposure have a significant impact on the amplification of resistance genes. (The project described in this paper has been registered at ClinicalTrials.gov under identifier NCT01208519.).

754P - Bone biomarkers and overall survival (OS) in men with castrate resistant prostate cancer (CRPC) and skeletal metastases: Updated results from SWOG 0421, a phase III trial of docetaxel +/- atrasentan

Skeletal metastasis is seen in most CRPC patients and is a common source of morbidity. We previously reported that bone biomarkers in CRPC patients are independently prognostic for OS, and that in men with highly elevated markers there is benefit from bone-targeted therapy (Lara, et al. JNCI 2014). Here we report our prospectively planned classification & regression tree (CART) analysis of clinical covariates and bone biomarkers as part of the phase III S0421 trial of docetaxel +/- atrasentan. Markers for bone resorption [N-telopeptide (NTx) & pyridinoline (PYD)] & formation [C-terminal collagen propeptide (CICP) & bone alkaline phosphatase (BAP)] were measured in pre-treatment sera from men on S0421. Bone biomarkers & baseline clinical covariates were included in a Cox model for OS; significant variables were allowed to compete in a CART analysis to identify prognostic groups using CTREE in the R package "party". Hazard ratios (HR) were calculated by comparing OS in each of the terminal nodes to a reference group in a Cox PH model. Kaplan Meier curves for each prognostic group defined by the tree were constructed. 750 men with evaluable bone marker & clinical data were included. Each bone marker significantly contributed to the final Cox model, with higher levels associated with worse OS. Cox stepwise selection identified BAP, CICP, PYD, hemoglobin (Hgb), pain score, age, black race, PSA, and visceral disease as associated with OS. CART analysis selected CICP, BAP, Hgb, & pain score for the final model, & identified 5 prognostic groups:Tabled 1Prognostic GroupDescriptionNMedian OS (months)Hazard Ratio (95% CI)p-value1Hgb < =11.317712.4REFREF2Hgb > 11.3 CICP < =6.819131.60.28 (0.22, 0.36)<0.0013Hgb > 11.3 CICP > 6.8 Worst pain > =414415.30.79 (0.63, 0.99)0.044Hgb > 11.3 CICP > 6.8 Worst pain < 4 BAP < =90.914027.10.34 (0.27, 0.44)<0.0015Hgb > 11.3 CICP > 6.8 Worst pain < 4 BAP > 90.99817.10.68 (0.53, 0.88)0.003 Open table in a new tab Elevated serum levels of bone biomarkers are strongly associated with worse OS in CRPC. CART analysis incorporating bone biomarkers identified five distinct prognostic CRPC groups with differential OS outcomes. These results further define & establish the role of bone biomarkers in the design and conduct of CRPC clinical trials.

Socio-economic and lifestyle parameters associated with diet quality of children and adolescents using classification and regression tree analysis: the DIATROFI study.

To explore factors affecting children's and adolescents' diet quality, in the framework of a food aid and promotion of healthy nutrition programme implemented in areas of low socio-economic status of Greece, during the current financial crisis. From a total of 162 schools participating in the programme during 2012-2013, we gathered 15 897 questionnaires recording sociodemographic characteristics, lifestyle parameters and dietary habits of children and their families. As a measure of socio-economic status, the Family Affluence Scale (FAS) was used; whereas for the assessment of diet quality, the KIDMED score was computed. Associations between KIDMED and FAS, physical activity and socio-economic parameters were examined using regression and classification-regression tree analysis (CART). The higher the FAS score, the greater the percentage of children and adolescents who reported to consume, on a daily basis, fruits and vegetables, dairy products and breakfast (P<0·001). Results from CART showed that children and adolescents in the medium or high FAS groups had higher KIDMED score, compared with those in the low FAS group. For those in the low FAS group, KIDMED score is expected to increase by 12·4 % when they spend more than 0·25 h/week in sports activities. The respective threshold for the medium and high FAS groups is 1·75 h/week, while education of the mother and father affected KIDMED score significantly as well. Diet quality is strongly influenced by socio-economic parameters in children and adolescents living in economically disadvantaged areas of Greece, so that lower family affluence is associated with worse diet quality.

Incident urothelial cancer in the Malmö Diet and Cancer Study: cohort characteristics and further validation of ezrin as a prognostic biomarker.

BackgroundReduced membranous expression of the cytoskeleton-associated protein ezrin has previously been demonstrated to correlate with poor prognosis in urothelial bladder cancer in several independent studies. The present study provides a first description of clinicopathological characteristics of incident urothelial cancers, not only located to the bladder, in the prospective, population-based cohort study Malmö Diet and Cancer. In addition, the prognostic value of ezrin expression is validated in primary tumours, and the longitudinal expression of ezrin examined in a subset of primary and recurrent tumours (n = 28).MethodsAmong a total number of 355 incident tumours registered up until Dec 31 2010, 335 were located to the bladder. Immunohistochemical expression of cytoplasmic and membranous ezrin was evaluated in tissue microarrays with primary tumours from 272 cases and recurrent tumours from 28 cases. A combined score of the minimum, mean and maximum fraction and percentage of staining was calculated. Classification regression tree analysis was applied for selection of prognostic cutoff. Kaplan-Meier analysis, log rank test, univariable and multivariable Cox regression proportional hazards’ modeling were used to evaluate the impact of ezrin expression on 5-year overall survival (OS).ResultsEzrin expression could be evaluated in 263/272 primary and all 28 recurrent tumours. Membranous but not cytoplasmic ezrin was significantly reduced in recurrent compared to primary tumours (p < 0.001). Low cytoplasmic and membranous ezrin expression were associated with more advanced T-stage (p = 0.004, p < 0.001) and high-grade tumours (p = 0.025, p < 0.001), but not with age, sex, tumour location or smoking status. Both low cytoplasmic and membranous ezrin staining were associated with a significantly reduced 5-year OS (HR = 1.65; 95% CI 1.06-2.57 and HR = 2.51, 95% CI 1.52-4.17), but only low membranous ezrin remained prognostic after adjustment for age, sex, stage, grade and smoking status (HR = 1.69, 95% CI 1.00-2.85).ConclusionsThis study provides a first description of the clinicopathological characteristics of 355 incident urothelial cancers in the Malmö Diet and Cancer Study up until 2010. In addition, the value of ezrin expression as a prognostic biomarker is further consolidated in this type of cancer.Virtual SlidesThe virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/13000_2014_189Electronic supplementary materialThe online version of this article (doi:10.1186/s13000-014-0189-5) contains supplementary material, which is available to authorized users.

Reduced expression of ezrin in urothelial bladder cancer signifies more advanced tumours and an impaired survival: validatory study of two independent patient cohorts.

BackgroundReduced membranous expression of the cytoskeleton-associated protein ezrin has previously been demonstrated to correlate with tumour progression and poor prognosis in patients with T1G3 urothelial cell carcinoma of the bladder treated with non-maintenance Bacillus Calmette-Guérin (n = 92), and the associations with adverse clinicopathological factors have been validated in another, unselected, cohort (n = 104). In the present study, we examined the prognostic significance of ezrin expression in urothelial bladder cancer in a total number of 442 tumours from two independent patient cohorts.MethodsImmunohistochemical expression of ezrin was evaluated in tissue microarrays with tumours from one retrospective cohort of bladder cancer (n = 110; cohort I) and one population-based cohort (n = 342; cohort II). Classification regression tree analysis was applied for selection of prognostic cutoff. Kaplan-Meier analysis, log rank test and Cox regression proportional hazards’ modeling were used to evaluate the impact of ezrin on 5-year overall survival (OS), disease-specific survival (DSS) and progression-free survival (PFS).ResultsEzrin expression could be evaluated in tumours from 100 and 342 cases, respectively. In both cohorts, reduced membranous ezrin expression was significantly associated with more advanced T-stage (p < 0.001), high grade tumours (p < 0.001), female sex (p = 0.040 and p = 0.013), and membranous expression of podocalyxin-like protein (p < 0.001 and p = 0.009). Moreover, reduced ezrin expression was associated with a significantly reduced 5-year OS in both cohorts (HR = 3.09 95% CI 1.71-5.58 and HR = 2.15(1.51-3.06), and with DSS in cohort II (HR = 2.77, 95% CI 1.78-4.31). This association also remained significant in adjusted analysis in Cohort I (HR1.99, 95% CI 1.05-3.77) but not in Cohort II. In pTa and pT1 tumours in cohort II, there was no significant association between ezrin expression and time to progression.ConclusionsThe results from this study validate previous findings of reduced membranous ezrin expression in urothelial bladder cancer being associated with unfavourable clinicopathological characteristics and an impaired survival. The utility of ezrin as a prognostic biomarker in transurethral resection specimens merits further investigation.

662: Association of Montevideo units with uterine rupture in women undergoing a trial of labor after cesarean delivery

662 Association of Montevideo units with uterine rupture in women undergoing a trial of labor after cesarean delivery Lindsay Maggio, Joanna Forbes, Haleh Sangi-Haghpeykar, Christina Davidson Baylor College of Medicine, Obstetrics and Gynecology, Houston, TX OBJECTIVE: To investigate if there is a threshold of uterine contraction strength, as measured by Montevideo units (MVUs), at which catastrophic uterine rupture always occurs and/or never occurs, as well as to determine if the rate of uterine rupture increases as MVUs increase. STUDY DESIGN: Retrospective chart review of women who underwent a trial of labor after cesarean (TOLAC) at a tertiary care academic hospital in Houston, TX, between January 2007 and June 2010. We included women with one prior cesarean delivery (CD) attempting TOLAC at 36 0/7 weeks gestational age or greater with a singleton gestation who had an intrauterine pressure catheter placed during their labor. Cases were those women who experienced a catastrophic uterine rupture during their TOLAC and controls had a successful vaginal birth after cesarean (VBAC). For each case, 6 controls were randomly selected. MVUs were calculated in 10 minute intervals for a total of 120 minutes prior to either delivery (controls) or to the time of planned CD for suspected uterine rupture (cases). Time zero was that time of delivery or planned CD. Cases and controls were compared via chi-square/fisher exact test for grouped variables and t-test for continuous outcomes. Ability of MVU time points to predict uterine rupture was assessed via logistic regression models and the corresponding Area Under the Curve (AUC) and Receiver Operative Characteristic (ROC). RESULTS: Eight cases were identified during the study time period and compared against 48 controls. When comparing MVUs, there was no statistically significant difference between the two groups at any time period except in the zero to ten minute interval (the 10 minutes immediately prior to successful VBAC or planned CD for uterine rupture). At this time point, the mean MVUs in the control group were actually higher than in the cases (271.2 vs. 151.9, p 0.0008), which remains true for almost every other time point, although not statistically significant. CONCLUSION: We did not find a correlation between MVUs and risk of uterine rupture in women undergoing a TOLAC. 663 Predicting cesarean delivery in the second stage of labor: a classification & regression tree (CART) analysis Lorie Harper, Anthony Odibo, George Macones, Alison Cahill Washington University in St. Louis, Department of Obstetrics and Gynecology, St. Louis, MO OBJECTIVE: While uncommon, cesarean delivery (CD) performed in the second stage is associated with increased maternal and neonatal morbidity compared to CD in the first stage of labor. We aimed to develop a prediction model for CD in the second stage of labor using a classification and regression tree (CART) analysis. STUDY DESIGN: A retrospective cohort study of all consecutive women admitted for labor 37.0 weeks gestation from 2004-2008 who reached the second stage of labor. The primary outcome was CD after reaching 10-cm dilation. Univariate and multivariate analyses were used to identify candidate risk factors for CD in the second stage of labor, and CART analysis was performed to identify risk factor scenarios that best discriminate between women who undergo a second stage CD and those who do not. Only factors known at the time a patient reaches 10-cm dilation were used in the analysis. RESULTS: Of 5,388 subjects who reached 10-cm dilation, 88 (1.6%) required CD. The logistic regression model identified 4 risk factors for CD and produced a receiver operator characteristic (ROC) curve with an area under the curve of 0.75. The ROC curve identified no optimal trade-off between sensitivity and specificity for predicting CD. CART analysis identified 6 dominant risk factors applied in 4 specific pathways to predict CD. The most important variable in predicting CD in the second stage was a station higher than 0 at complete dilatation. Pathways predicting no CD resulted in CD rates of 0-0.6%. Pathways that predicted CD had CD rates of 2.5-5.1%. Using this prediction model, 1,791 (34%) of women who delivered vaginally would have been misclassified as requiring CD. CONCLUSION: Despite being able to identify risk factors associated with need for cesarean in the second stage of labor, cesarean delivery in the second stage of labor cannot be reliably predicted based on antenatal and intrapartum characteristics by logistic regression or CART techniques. PosterSessionIV Epidemiology, Infectious Disease, Intrapartum Fetal Assessment, Operative Obstetrics, Obstetric Quality & Safety, Public Health-Global Health www.AJOG.org

A classification and regression tree analysis for the evaluation of the role of nutritional services on cardiovascular disease risk status of older people living in Greek islands and Cyprus

Introduction: The purpose of this study was to evaluate, with classification–regression tree analysis, the structure of the associations between nutritional and health care services and the cumulative prevalence of the classical cardiovascular disease (CVD) risk factors of older individuals living in Greek islands and Cyprus. Methods: During 2005–2009, 744 men and 742 women (>65 years) from nine Greek islands and Cyprus Republic were voluntarily enrolled in the Mediterranean Islands study; various socio-demographic, clinical and lifestyle characteristics were recorded. Moreover, information regarding practising dieticians (n = 88) and nutritional services provided in these islands was also recorded. Results: Both medical and nutrition services act more effectively to elders' cardiovascular health. For example, older individuals living in areas with nutritional services' support for at least five years, with collaboration between dieticians and physicians, reduced the CVD risk factors (CVD RF) burden by 42%. Whereas, in areas with dietetic support less than five years, but more than two, the presence of advanced health care system seemed to control the CVD RF burden to the population average. Conclusions: Despite the fact that the present work shares some limitations mainly because of its cross-sectional design, the classification and regression tree approach has clearly demonstrated the interrelation between nutritional services and the health care system towards achieving benefits among the elders' quality of life.

Evaluation of the prognostic significance of MSMB and CRISP3 in prostate cancer using automated image analysis

Despite prostate cancer being the most frequent cancer in men in the Western world, tissue biomarkers for predicting disease recurrence after surgery have not been incorporated into clinical practice. Our group has previously identified β-microseminoprotein (MSMB) and cysteine-rich secretory protein-3 (CRISP3) as independent predictors of biochemical recurrence after radical prostatectomy. The purpose of the present study was to use automated image analysis, enabling quantitative determination of MSMB and CRISP3 expressions in a large cohort and to validate the previous findings. MSMB and CRISP3 protein expressions were assessed on tissue microarrays constructed from 3268 radical prostatectomy specimens. Whole-slide digital images were captured, and a novel cytoplasmic algorithm was used to develop a quantitative scoring model for cytoplasmic staining. Classification regression tree analysis was used to group patients, with different risk for biochemical recurrence, depending on level of protein expression. Patients with tumors expressing high levels of MSMB had a significantly reduced risk for biochemical recurrence after radical prostatectomy (HR=0.468; 95% CI 0.394–0.556; P<0.001). Multivariate analysis adjusted for clinicopathological parameters revealed that MSMB expression was an independent predictor of decreased risk of recurrence (HR=0.710; 95% CI 0.578–0.872; P<0.001). We found no correlation between CRISP3 expression and biochemical recurrence. In this current study, we applied a novel image analysis on a large independent cohort and successfully verified that MSMB is a strong independent factor, predicting favorable outcome after radical prostatectomy for localized prostate cancer.

Effects of perindopril on cardiac remodelling and prognostic value of pre-discharge quantitative echocardiographic parameters in elderly patients after acute myocardial infarction: the PREAMI echo sub-study

To determine (i) the effect of perindopril on several geometric and functional parameters of the left and right ventricles assessed by echocardiography in the unique Perindopril and Remodelling in Elderly with Acute Myocardial Infarction (PREAMI) population of post-acute myocardial infarction (AMI) elderly patients with preserved left ventricular (LV) function; and (ii) the prognostic predictors at pre-discharge derived from echo-Doppler measurements in the same population. PREAMI included 1252 post-AMI patients (age 73 +/- 6 years, LV ejection fraction 59.1 +/- 7.7%) receiving optimal therapy after AMI, randomized to perindopril 8 mg/day (n = 631) or placebo (n = 621); n = 896 had complete echo-Doppler data. Outcome measures were clinical [death, heart failure (HF)] and standard echo-Doppler parameters. Pre-discharge LV end-diastolic volume (LVEDV) was similar: 81.1 +/- 23.1 (perindopril) and 79.6 +/- 22.7 mL (placebo). At 6 months and 1 year, LVEDV remained unchanged with perindopril (81.2 +/- 24.4 and 81.8 +/- 26.8 mL, respectively), but increased with placebo (83.0 +/- 25.3 and 83.6 +/- 25.7 mL, respectively, both P < 0.001 vs. baseline). Perindopril reduced cardiac sphericity vs. placebo (P = 0.015 at 6 months; P = 0.020 at 1 year). Classification regression tree analysis showed treatment as the most important predictor of remodelling. Multiple pre-discharge echocardiographic variables predicted the death/HF endpoint, independently of treatment (P < or = 0.05). Remodelling occurs in post-AMI in elderly patients with normal LV function. Echo-Doppler variables at baseline have prognostic implications. Treatment with perindopril reduces progressive LV remodelling that can occur even in the case of small infarct size.

660: Uterine rupture in VBAC: Prediction with classification & regression tree analysis

TREE ANALYSIS DAVID STAMILIO, ALISON CAHILL, ANTHONY ODIBO, WILLIAM SHANNON, JEFFREY PEIPERT, GEORGE MACONES, Washington University in St. Louis, St. Louis, Missouri OBJECTIVE: To predict uterine rupture in vaginal birth after cesarean (VBAC) patients using classification & regression tree (CART) analysis. Prior attempts to predict uterine rupture in VBAC using classic logistic regression modelling have been unsuccessful. The CART method can assess more complex risk factor relationships and provide more accurate & practical prediction rules by progressively splitting patients into intuitive risk factor subgroups. STUDY DESIGN: A multi-center retrospective cohort study of pregnant women with at least one prior cesarean between 1995 & 2000. This secondary analysis includes only patients that attempted VBAC. The primary outcome is symptomatic uterine rupture. We used univariate & multivariable methods to identify over 20 candidate risk factors and CART analysis to develop a multivariable prediction model for uterine rupture. RESULTS: Of 13,705 VBAC attempts, 128 cases (0.9%) of uterine rupture occurred. CART analysis identified 5 dominant risk factors applied in 5 specific pathways (or scenarios) to predict uterine rupture (see table). Only scenario 1 had a uterine rupture rate appreciably higher than baseline risk.

Immunohistochemical markers for intracranial ependymoma recurrence: An analysis of 88 cases

Intracranial ependymomas are the third most common primary brain tumor in children. Although clinical and histological criteria for ependymoma prognosis are recognized, studies have reported contradictory results. Prognostic significance based on immunohistochemistry of ependymomas has been reported in a few studies. Eighty-eight patients with intracranial ependymomas were examined retrospectively for immunoexpression of various tumor-associated antigens and apoptosis. The results demonstrated significant preponderance of expression of the tenascin, vascular endothelial growth factor protein (VEGF), epidermal growth factor (EGFR), and p53 protein in high-grade tumors. Also high-grade ependymomas revealed more prominent labeling indices (LI) for proliferative marker Ki-S1 and lower LI for cyclin-dependent kinase inhibitor p27/Kip1. For low-grade ependymomas the progression free survival time (PFS) was found to be significantly shorter for Ki-S1 LI≥5%, and for tenascin, VEGF, and EGFR positivity. For high-grade ependymomas PFS was found to be significantly reduced for age <16 years, subtotal tumor removal, p27 LI <20%, p53 positivity, and for apoptotic index (AI) <1%. The classification regression tree analysis exhibited four groups of ependymomas; (1) low-grade tenascin negative (32 cases, recurrence rate=0), (2) high-grade with AI ≥1% (21 cases, recurrence rate=57%), (3) low-grade tenascin-positive (10 cases, recurrence rate=89%), and (4) high-grade with AI <1% (25 cases, recurrence rate=100%). So, the immunohistochemical variables were found to be strongest predictors of ependymoma recurrence and they seem to be useful for assessing individual tumor prognosis in routinely processed biopsy specimen.

Prevalence of feeding tube placement errors & associated risk factors in children.

The purpose of this study was to determine the prevalence of feeding tube placement errors in children. The hospital records of 201 children having both an enteral tube and at least one radiograph showing tube placement were retrospectively reviewed. Chart review was also used to determine the risk factors associated with these errors. Tube placement error was defined as tube tip or orifices in the esophagus or intestine (if the tube was supposed to be in the stomach) or tip or orifices in the esophagus or stomach (if the tube was supposed to be in the intestine.) On the first day, a radiograph documenting tube placement showed that 32 of the 201 children (15.9%) had tube placement errors. Overall, 53 tube placement errors were evident during the 385 observation days on which radiographs were obtained (13.8%). Of the 201 children, 42 (20.9%) had experienced tube placement errors at some time during the period reviewed. Over all radiograph days, activity level was independently related to radiographic tube placement (p = < 0.02), with more errors among active children. Also, classification regression tree analysis showed that age, level of consciousness (alert or comatose versus semicomatose), abdominal distention, vomiting, and orogastric tubes were associated with more tube placement errors. Nurses need to be especially careful in assessing tube placement if the pediatric client has one or more of the identified risk factors. Health care providers need to carefully weigh the benefits and risks of feeding by nasal or oral enteral tubes versus the benefits and risks of feeding by endoscopically or surgically placed enteral tubes.