A decision support system to facilitate management of patients with acute gastrointestinal bleeding

Objective: To develop a model to predict the bleeding source and identify the cohort amongst patients with acute gastrointestinal bleeding (GIB) who require urgent intervention, including endoscopy. Patients with acute GIB, an unpredictable event, are most commonly evaluated and managed by non-gastroenterologists. Rapid and consistently reliable risk stratification of patients with acute GIB for urgent endoscopy may potentially improve outcomes amongst such patients by targeting scarce health-care resources to those who need it the most. Design and methods: Using ICD-9 codes for acute GIB, 189 patients with acute GIB and all. available data variables required to develop and test models were identified from a hospital medical records database. Data on 122 patients was utilized for development of the model and on 67 patients utilized to perform comparative analysis of the models. Clinical data such as presenting signs and symptoms, demographic data, presence of co-morbidities, laboratory data and corresponding endoscopic diagnosis and outcomes were collected. Clinical data and endoscopic diagnosis collected for each patient was utilized to retrospectively ascertain optimal management for each patient. Clinical presentations and corresponding treatment was utilized as training examples. Eight mathematical models including artificial neural network (ANN), support vector machine (SVM), k-nearest neighbor, linear discriminant analysis (LDA), shrunken centroid (SC), random forest (RF), logistic regression, and boosting were trained and tested. The performance of these models was compared using standard statistical analysis and ROC curves. Results: Overall the random forest model best predicted the source, need for resuscitation, and disposition with accuracies of approximately 80% or higher (accuracy for endoscopy was greater than 75%). The area under ROC curve for RF was greater than 0.85, indicating excellent performance by the random forest model Conclusion: While most mathematical models are effective as a decision support system for evaluation and management of patients with acute GIB, in our testing, the RF model consistently demonstrated the best performance. Amongst patients presenting with acute GIB, mathematical models may facilitate the identification of the source of GIB, need for intervention and allow optimization of care and healthcare resource allocation; these however require further validation. (c) 2007 Elsevier B.V. All rights reserved.

Experimental Model of Isolated Lung Perfusion in Rats: First Brazilian Experience Using the IL-2 Isolated Perfused Rat or Guinea Pig Lung System

Introduction. Lung transplantation has become the mainstay therapy for patients with end-stage lung disease refractory to medical management. However, the number of patients listed for lung transplantation largely exceeds available donors. The study of lung preservation requires accurate, cost-effective small animal models. We have described a model of ex vivo rat lung perfusion using a commercially available system. Methods. Male Wistar rats weighing 250 g-300 g were anesthetized with intraperitoneal sodium thiopental (50 mg/kg body weight). The surgical technique included heart-lung block extraction, assembly, and preparation for perfusion and data collection. We used an IL-2 Isolated Perfused Rat or Guinea Pig Lung System (Harvard Apparatus, Holliston, Mass, United States; Hugo Sachs Elektronik, Alemanha). Results. Preliminary results included hemodynamic and pulmonary mechanics data gathered in the experiments. Conclusion. The isolated rat lung perfusion system is a reliable method to assess lung preservation.

Validity and reliability of a computer method to estimate vertebral axial rotation from digital radiographs

Axial vertebral rotation, an important parameter in the assessment of scoliosis may be identified on X-ray images. In line with the advances in the field of digital radiography, hospitals have been increasingly using this technique. The objective of the present study was to evaluate the reliability of computer-processed rotation measurements obtained from digital radiographs. A software program was therefore developed, which is able to digitally reproduce the methods of Perdriolle and Raimondi and to calculate semi-automatically the rotation degree of vertebra on digital radiographs. Three independent observers estimated vertebral rotation employing both the digital and the traditional manual methods. Compared to the traditional method, the digital assessment showed a 43% smaller error and a stronger correlation. In conclusion, the digital method seems to be reliable and enhance the accuracy and precision of vertebral rotation measurements.

Magnetic purification of biotinylated cDNA removes false priming and ensures strand-specificity of RT-PCR for enteroviral RNAs

The detection of replicative intermediate RNAs as markers of active replication of RNA viruses is an essential tool to investigate pathogenesis in acute viral infections, as well as in their long-term sequelae. In this regard, strand-specific PCR has been used widely to distinguish (-) and (+) enteroviral RNAs in pathogenesis studies of diseases such as dilated cardiomyopathy. It has been generally assumed that oligonucleotide-primed reverse transcription of a given RNA generates only the corresponding specific cDNA, thus assuring the specificity of a PCR product amplified from it. Nevertheless, such assumed strand-specificity is a fallacy, because falsely primed cDNAs can be produced by RNA reverse transcription in the absence of exogenously added primers, (cDNA(primer)(-)), and such falsely primed cDNAs are amplifiable by PCR in the same way as the correctly primed cDNAs. Using as a prototype the coxsackievirus B5 (CVB5), a (+) strand RNA virus, it was shown that cDNA(primer)(-) renders the differential detection of viral (-) and (+) RNAs by conventional PCR virtually impossible, due to gross non-specificity. Using in vitro transcribed CVB5 RNAs (+) and (-), it was shown that cDNA(primer)(-) could be removed effectively by magnetic physical separation of correctly primed biotinylated cDNA. Such strategy enabled truly strand-specific detection of RNA (-) and (+), not only for CVB5, but also for other non-polio enteroviruses. These findings indicate that previous conclusions supporting a role for the persistence of actively replicating enterovirus in the pathogenesis of chronic myocarditis should be regarded with strong skepticism and purification of correctly primed cDNA should be used for strand-specific PCR of viral RNA in order to obtain reliable information on this important subject. (C) 2009 Elsevier B.V. All rights reserved.

Characterization of juvenile and young adult mice following induction of hydrocephalus with kaolin

Hydrocephalus is a common neurological problem in humans, Usually caused by an impairment of cerebrospinal fluid (CSF) flow or absorption. A reliable induced model of chronic hydrocephalus in mice would be useful to test hypotheses using genetic mutants. Our goal was to characterize behavioral and histological changes in juvenile and Young adult mice with kaolin (aluminum silicate) -induced hydrocephalus. Seven-day old and 7-8 week old mice received injection of kaolin into the cisterna magna. Behavior was assessed repeatedly. Seven or 14 days following kaolin, magnetic resonance (MR) imaging was used to assess ventricle size. In hydrocephalic mice, body weight was significantly lower than in age-matched saline-injected sham controls and the gait and posture score were impaired. Juvenile mice developed severe ventriculomegaly and had reduced corpus callosum thickness with gross white matter destruction by 14 days. Reactive astroglial change in white matter and cortex and reduced cellular proliferation in the subependymal zone were also apparent. Young adult mice developed only moderate ventricular enlargement without overt white matter destruction, although there was corpus callosum atrophy and mild astroglial reaction in white matter. Glial fibrillary acidic protein content was significantly higher in juvenile and young adult hydrocephalic mice at 7 and 14 days, but myelin basic protein content was not significantly altered. In conclusion, hydrocephalus induced by percutaneous injection of kaolin in juvenile and young adult mice is feasible. The associated periventricular alterations are essentially the same as those reported in rats of comparable ages. (C) 2009 Elsevier Inc. All rights reserved.

Validation of ACB in vitro and in vivo as a biomagnetic method for measuring stomach contraction

Background The aim of this study was to validate a biomagnetic method (alternate current biosusceptometry, ACB) for monitoring gastric wall contractions in rats. Methods In vitro data were obtained to establish the relationship between ACB and the strain-gauge (SG) signal amplitude. In vivo experiments were performed in pentobarbital-anesthetized rats with SG and magnetic markers previously implanted under the gastric serosa or after ingestion of magnetic material. Gastric motility was quantified from the tracing amplitudes and frequency profiles obtained by Fast Fourier Transform. Key Results The correlation between in vitro signal amplitudes was strong (R = 0.989). The temporal cross-correlation coefficient between the ACB and SG signal amplitude was higher (P < 0.0001) in the postprandial (88.3 +/- 9.1 V) than in the fasting state (31.0 +/- 16.9 V). Irregular signal profiles, low contraction amplitudes, and smaller signal-to-noise ratios explained the poor correlation between techniques for fasting-state recordings. When a magnetic material was ingested, there was also strong correlation in the frequency and signal amplitude and a small phase-difference between the techniques. The contraction frequencies using ACB were 0.068 +/- 0.007 Hz (postprandial) and 0.058 +/- 0.007 Hz (fasting) (P < 0.002) and those using SG were 0.066 +/- 0.006 Hz (postprandial) and 0.059 +/- 0.008 Hz (fasting) (P < 0.005). Conclusions & Inferences In summary, ACB is reliable for monitoring gastric wall contractions using both implanted and ingested magnetic materials, and may serve as an accurate and sensitive technique for gastrointestinal motility studies.

Comparative analysis of two immunohistochemical methods for antigen retrieval in the optical lobe of the honeybee Apis mellifera: Myosin-v assay

The present study compared two heating methods currently used for antigen retrieval (AR) immunostaining: the microwave oven and the steam cooker. Myosin-V, a molecular motor involved in vesicle transport, was used as a neuronal marker in honeybee Apis mellifera brains fixed in formalin. Overall, the steam cooker showed the most satisfactory AR results. At 100 degrees C, tissue morphology was maintained and revealed epitope recovery, while evaporation of the AR solution was markedly reduced; this is important for stabilizing the sodium citrate molarity of the AR buffer and reducing background effects. Standardization of heat-mediated AR of formalin-fixed and paraffin-embedded tissue sections results in more reliable immunostaining of the honeybee brain.

Study of spontaneous recurrent seizures and morphological alterations after status epilepticus induced by intrahippocampal injection of pilocarpine

Epileptic seizures are clinical manifestations of neuronal discharges characterized by hyperexcitability and/or hypersynchrony in the cortex and other subcortical regions. The pilocarpine (PILO) model of epilepsy mimics temporal lobe epilepsy (TLE) in humans. In the present study, we used a more selective approach: microinjection of PILO into the hilus of the dentate gyrus (H-PILO). Our main goal was to evaluate the behavioral and morphological alterations present in this model of TLE. Seventy-six percent of all animals receiving H-PILO injections had continuous seizures called status epilepticus (SE). A typical pattern of evolution of limbic seizures during the SE with a latency of 29.3 +/- 16.3 minutes was observed using an analysis of behavioral sequences. During the subsequent 30 days, 71% of all animals exhibited spontaneous recurrent seizures (SRSs) during a daily 8-hour videotaping session. These SRSs had a very conspicuous and characteristic pattern detected by behavioral sequences or neuroethological analysis. Only the animals that had SE showed positive Neo-Timm staining in the inner molecular layer of the dentate gyrus (sprouting) and reduced cell density in Ammon`s horn pyramidal cell subfield CA1. However, no correlation between the intensity of sprouting and the mean number and total number of SRSs was found. Additionally, using Fluoro-Jade staining, we observed neurodegeration in the hilus and pyramidal cell subfields CA3 and CM 24 hours after SE. These data indicate that H-PILO is a reliable, selective, efficient, low-mortality model that mimics the acute and chronic behavioral and morphological aspects of TLE. (C) 2010 Elsevier Inc. All rights reserved.

Identification of genetic alterations by multiple ligation-dependent probe amplification (MLPA) analysis in oligodendrogliomas

Concurrent deletion at 1p/19q is a common signature of oligodendrogliomas, and it may, be identified in low-grade tumours (grade II) suggesting it represents an early event in the development of these brain neoplasms. Additional non-random changes primarily involve CDKN2A, PTEN and EGFR. Identification of all of these genetic changes has become an additional parameter in the evaluation of the clinical patients` prognosis, including good response to conventional chemotherapy. Multiple ligation-dependent probe amplification (MLPA) analysis is a new methodology that allows an easy identification of the oligodendrogliomas` abnormalities in a single step. No need of the respective constitutional DNA from each patient is another advantage of this method. We used MLPA kits P088 and P105 to determine the molecular characteristics of a series of 40 oligodendrogliomas. Deletions at I p and 19q were identified in 45% and 65% of cases, respectively. Alterations of EGFR, CDKN2A, ERBB2, PTEN and TP53 were also identified in variable frequencies among 7% to 35% of tumours. These findings demonstrate that MLPA is a reliable technique to the detection of molecular genetic changes in oligodendrogliomas.

PULSATILITY INDEX CHANGE OF BRACHIAL ARTERY SHOWS BETTER REPRODUCIBILITY THAN FLOW-MEDIATED VASODILATION

We aim to evaluate intra- and interobserver reproducibility of brachial artery flow-mediated dilation (FMD) and of pulsatility index change (PI-C) 1 min after a 5-min forearm compression in pregnant women. Flow-mediated dilation and PI-C were assessed in 31 healthy pregnant women in 3 consecutive days, by two observers. A broader range of response to the stimulus was observed for PI-C (-58.99%-86.71%) than FMD (2.38%-27.01%). The intraclass correlation coefficients were higher for PI-C than for FMD (intra = 0.90 vs. 0.69, p = 0.047; inter = 0.94 vs. 0.61, p = 0.007). Therefore, PI-C measurements were more reliable than FMD. However, studies comprising of subjects with cardiovascular risk factors relating FMD and PI-C become necessary to validate this method for the study of endothelial dysfunction. (E-mail: wpmartins@gmail.com) (C) 2010 World Federation for Ultrasound in Medicine & Biology.

Influence of third-generation oral contraceptives on the complexity analysis and symbolic dynamics of heart rate variability

Objective To evaluate the influence of oral contraceptives (OCs) containing 20 mu mu g ethinylestradiol (EE) and 150 mu mu g gestodene (GEST) on the autonomic modulation of heart rate (HR) in women. Methods One-hundred and fifty-five women aged 24 +/-+/- 2 years were divided into four groups according to their physical activity and the use or not of an OC: active-OC, active-non-OC (NOC), sedentary-OC, and sedentary-NOC. The heart rate was registered in real time based on the electrocardiogram signal for 15 minutes, in the supine-position. The heart rate variability (HRV) was analysed using Shannon`s entropy (SE), conditional entropy (complexity index [CInd] and normalised CInd [NCI]), and symbolic analysis (0V%, 1V%, 2LV%, and 2ULV%). For statistical analysis the Kruskal-Wallis test with Dunn post hoc and the Wilcoxon test (p < 0.05 was considered significant) were applied. Results Treatment with this COC caused no significant changes in SE, CInd, NCI, or symbolic analysis in either active or sedentary groups. Active groups presented higher values for SE and 2ULV%, and lower values for 0V% when compared to sedentary groups (p < 0.05). Conclusion HRV patterns differed depending on life style; the non-linear method applied was highly reliable for identifying these changes. The use of OCs containing 20 mu mu g EE and 150 mu mu g GEST does not influence HR autonomic modulation.

A standardized measurement technique may improve the reliability of measurements of endometrial thickness and volume

Objective To investigate whether standardization of the multiplanar view (SMV) when evaluating the uterus using three-dimensional ultrasonography (3D-US) improves intra-and interobserver reliability and agreement with regard to endometrial measurement. Methods Two-dimensional (2D) and 3D-US was used to measure endometrial thickness by two observers in 30 women undergoing assisted reproduction treatment. Endometrial volume was measured with Virtual Organ Computer-aided AnaLysis (VOCAL (TM)) in the longitudinal (A) and coronal (C) planes using an unmodified multiplanar view (UMV) and a standardized multiplanar view (SMV). Measurement reliability was evaluated by intraclass correlation coefficient (ICC) and agreement was examined using Bland-Altman plots with limits of agreement (LoA). The ease of outlining the endometrial-myometrial interface was compared between the A-and C-planes using subjective assessment. Results Endometrial volume measurements using the SMV and A-plane were more reliable (intra-and interobserver ICCs, 0.979 and 0.975, respectively) than were measurements of endometrial thickness using 2D-US (intra-and interobserver ICCs, 0.742 and 0.702, respectively) or 3D-US (intra-and interobserver ICCs, 0.890 and 0.784, respectively). The LoAs were narrower for SMV than for UMV. Reliability and agreement were not much different between the A- and C-planes. However the observers agreed that delineating the endometrial-myometrial interface using the A-plane was easier (first and second observer, 50.0 and 46.7%, respectively) or `comparable` (50 and 53.3%, respectively), but never more difficult than using the C-plane. Conclusions Endometrial volume measurements are more reliable than endometrial thickness measurements and are best performed using SMV and the A-plane. Copyright (C) 2011 ISUOG. Published by John Wiley & Sons, Ltd.

Expanded protocol of orofacial myofunctional evaluation with scores: Validity and reliability

Objective: Clinical evaluation of the stomatognathic system is indispensable for the diagnosis of orofacial myofunctional disorders. In order to obtain a more precise diagnosis, the protocol of orofacial myofunctional evaluation with scores (OMES protocol) (Int. J. Pediatr. Otorhinolaryngol. 72 (2008) 367-375) was expanded in terms of number of items and scale amplitude. The proposal of this study is to describe the expanded OMES protocol (OMES-E) for the evaluation of children. Validity of the protocol, reliability of the examiners and agreement between them were analyzed, as also were the sensitivity, specificity and predictive values of the instrument. Methods: The sample consisted of videorecorded images of 50 children, 25 boys (mean age = 8.4 years, SD = 1.8) and 25 girls (mean age = 8.2 years, SD = 1.7) selected at random from 200 samples. Three speech therapists prepared for orofacial myofunctional evaluation participated as examiners (E). The OMES and OMES-E protocols were used for evaluation on different days. E1 evaluated all images, E2 analyzed children with recordings from 1 to 25 and E3 analyzed children with recordings from 26 to 50. The validity of OMES-E was analyzed by comparing the instrument to the OMES protocol using the Pearson correlation test complemented with the split-half reliability test (p < 0.05). The linear weighted Kappa coefficient of agreement (Kw`), the sensitivity, specificity and predictive values and the prevalence of OMD were calculated. Results: There was a statistically significant correlation between the OMES and OMES-E protocols (0.79 > r < 0.94, p < 0.01) and a significant test-retest correlation with the OMES-E (0.75 > r < 0.86, p < 0.01), with a reliability range of 0.86-0.93. The correlation and reliability coefficients between examiners were: E1 x E2 (r = 0.74, 0.84), E1 x E3 (r = 0.70, 0.83) (p < 0.01). Kw` coefficients with moderate and good strength predominated. The OMES-E protocol presented mean sensitivity = 0.91, specificity = 0.77, positive predictive value = 0.87 and negative predictive value = 0.85. The mean prevalence of OMD was 0.58. Conclusion: The OMES-E protocol is valid and reliable for orofacial myofunctional evaluation. (C) 2010 Elsevier Ireland Ltd. All rights reserved.

Protocol of orofacial myofunctional evaluation with scores

Objective: In the literature there is no validated instrument for the clinical evaluation of the orofacial myofunctional condition of children that will permit the examiner to express numerically his perception of the characteristics and behaviors observed. The proposal of this study is to describe a protocol for the evaluation of children aged 6-12 years in order to establish relations between the orofacial. myofunctional conditions and numerical scales. The protocol validity, reliability of the examiners and agreement between them was analyzed. Methods: Eighty children aged 6-12 years participated in the study. All were evaluated and 30 were selected at random for the analyses (age range: 72-149 months, mean = 103.3, S.D. = 23.57). Individuals with and without orofacial myofunctional. disorders were included. The examiners were two speech therapists property calibrated in orofacial myofunctional evaluation. Two protocols were constructed. One, based on traditional models, was called traditional orofacial. myofunctional. evaluation (TOME), and the other, with the addition of numerical scales, was called orofacial myofunctional. evaluation with scores (OMES). The clinical conditions included were: appearance, posture and mobility of lips, tongue, cheeks and jaws, respiration, mastication and deglutition. Statistical analysis was performed using the split-half reliability method. Means, standard deviations and the Spearman correlation coefficient were also calculated. Results: There was a statistically significant correlation between the evaluations of 30 children assessed with the TOME and OMES protocols (r = 0.85, p < 0.01). The reliability between protocols was 0.92. The test-retest reliability of the OMES instrument was 0.99 and the correlation was 0.98. Reliability between examiners 1 and 2 using the OMES protocol was 0.99, and the correlation was 0.98 (P < 0.01). Conclusion: The OMES protocot proved to be a valid and reliable instrument for orofacial myofunctional evaluation, permitting the grading of orofacial myofunctional conditions within the limits of the selected items. (c) 2007 Elsevier Ireland Ltd. All rights reserved.

Methotrexate Withdrawal at 6 vs 12 Months in Juvenile Idiopathic Arthritis in Remission A Randomized Clinical Trial

Context Novel therapies have improved the remission rate in chronic inflammatory disorders including juvenile idiopathic arthritis (JIA). Therefore, strategies of tapering therapy and reliable parameters for detecting subclinical inflammation have now become challenging questions. Objectives To analyze whether longer methotrexate treatment during remission of JIA prevents flares after withdrawal of medication and whether specific biomarkers identify patients at risk for flares. Design, Setting, and Patients Prospective, open, multicenter, medication-withdrawal randomized clinical trial including 364 patients (median age, 11.0 years) with JIA recruited in 61 centers from 29 countries between February 2005 and June 2006. Patients were included at first confirmation of clinical remission while continuing medication. At the time of therapy withdrawal, levels of the phagocyte activation marker myeloid-related proteins 8 and 14 heterocomplex (MRP8/14) were determined. Intervention Patients were randomly assigned to continue with methotrexate therapy for either 6 months (group 1 [n = 183]) or 12 months (group 2 [n = 181]) after induction of disease remission. Main Outcome Measures Primary outcome was relapse rate in the 2 treatment groups; secondary outcome was time to relapse. In a prespecified cohort analysis, the prognostic accuracy of MRP8/14 concentrations for the risk of flares was assessed. Results Intention-to-treat analysis of the primary outcome revealed relapse within 24 months after the inclusion into the study in 98 of 183 patients (relapse rate, 56.7%) in group 1 and 94 of 181 (55.6%) in group 2. The odds ratio for group 1 vs group 2 was 1.02 (95% CI, 0.82-1.27; P=.86). The median relapse-free interval after inclusion was 21.0 months in group 1 and 23.0 months in group 2. The hazard ratio for group 1 vs group 2 was 1.07 (95% CI, 0.82-1.41; P=.61). Median follow-up duration after inclusion was 34.2 and 34.3 months in groups 1 and 2, respectively. Levels of MRP8/14 during remission were significantly higher in patients who subsequently developed flares (median, 715 [IQR, 320-1110] ng/mL) compared with patients maintaining stable remission (400 [IQR, 220-800] ng/mL; P=.003). Low MRP8/14 levels indicated a low risk of flares within the next 3 months following the biomarker test (area under the receiver operating characteristic curve, 0.76; 95% CI, 0.62-0.90). Conclusions In patients with JIA in remission, a 12-month vs 6-month withdrawal of methotrexate did not reduce the relapse rate. Higher MRP8/14 concentrations were associated with risk of relapse after discontinuing methotrexate.