Hatem Bellaaj

Clinical utility and prognostic value of galactomannan in neutropenic patients with invasive aspergillosis

UNLABELLED Invasive aspergillosis (IA) is a major cause of morbidity and mortality in profoundly neutropenic patients. Delayed diagnosis and therapy may lead to poor outcomes. AIMS The objective of this study was to assess the performance characteristics of the galactomannan (GM) assay in serum and bronchoalveolar lavage specimens for the diagnosis of IA in neutropenic patients with hematological malignancies. We also evaluated the prognostic outcome. PATIENTS AND METHODS A total of 1198 serum samples and 42 BAL from 235 neutropenic patients were tested with a GM elisa platelia test. We used Cox modeling of time to 6- and 12-week mortality for GM level at the time of diagnosis (GM0) and GM decay in the week following diagnosis in proven and probable IA patients with more than two GM values. RESULTS There were three proven, 55 probable, and four possible cases of IA. The sensitivity and specificity of the GM test were 96.8% and 82.4% respectively. In BAL samples, sensitivity was 86% and the specificity 93%. BAL GM was more sensitive than microscopy (22.2%) and BAL culture (38.9%). Among patients with proven/probable IA, serum and BAL GM were in agreement for 92.8% of paired samples. The hazard ratio (HR) of GM0 and 1-week GM decay per unit increase in Aspergillus enzyme immunoassay (EIA) was 1.044 (95% CI, 0.738 to 1.476) and 0.709 (95% CI, 0.236 to 2.130) respectively. CONCLUSION We found good correlation between the GM0 and GM decay combination and outcome of IA patients. The GM is a useful tool for diagnosis and monitoring of IA.

Acute acalculous cholecystitis complicating chemotherapy for acute myeloblastic leukemia

Acute acalculous cholecystitis is a rare complication in the treatment of acute myeloblastic leukemia. Diagnosis of acute acalculous cholecystitis remains difficult during neutropenic period. We present two acute myeloblastic leukemia patients that developed acute acalculous cholecystitis during chemotherapy-induced neutropenia. They suffered from fever, vomiting and acute pain in the epigastrium. Ultrasound demonstrated an acalculous gallbladder. Surgical management was required in one patient and conservative treatment was attempted in the other patient. None treatment measures were effective and two patients died. Acute acalculous cholecystitis is a serious complication in neutropenic patients. Earlier diagnosis could have expedited the management of these patients.

A Web-Based Knowledge Management System for Scientific Research Team

Scientific research teams have immense valuable knowledge that need to be managed. Organizing scientific contributions of team members constitutes a major challenge for the monitoring of knowledge evolution, team member’s competences discovery, and facilitating information retrieval processes. However, performing manual annotations is often time consuming and labor-intensive task, especially in case of complex annotation schemas. Currently, existing knowledge management systems focus on ensuring the scientific knowledge creation, sharing, organization and evaluation but don’t provide a way for helping researchers in the classification task. In this paper, we introduce a knowledge management system that offers an annotation service for researchers’ contributions by including some natural language processing techniques. The provided service process comprises four phases: (1) the semantic enrichment of domain ontology based on the extraction of background data from Babelnet knowledge base, (2) the automatic generation of candidate categories using the enriched domain ontology, (3) the forwarding of the pre-annotated papers to our web-based system to interact with researchers, and finally (4) the human revision of the generated annotations. Evaluation results show its advantage not only in reducing human effort and time consumption during the annotation task but also in improving annotations quality.

An adaptive neuro-fuzzy inference system for improving data quality in disease registries

The purpose of disease registries is to collect and analyze data related to specific diseases in terms of incidence and prevalence. Since the data is typically entered by wearable sensors and/or human caregivers, errors in the data fields are often inevitable. In this paper, we propose a new approach to improve data quality in disease registries based on (a) a semi-random combination of parameters and (b) a learning algorithm for detecting and signaling the loss of quality of the entered data. To implement the approach, we have developed a novel adaptive neuro-fuzzy inference system. It is applied to specific sections of the Tunisian Fanconi Anemia Registry with the aims of reducing false alarms and automatically adjusting the parameters of coefficients of the disease. Our experimental results indicate that both aims can be achieved and effectively lead to improved data quality in disease registries.

rMatcher: A Tool for Semantic Web Services Discovery & Publication

Web services have become an industrial standard offering interoperability among various platforms. With their proliferation, it is becoming increasingly difficult to find a web service that satisfies ones requirements. Yet, discovering the most relevant ones is a key solution to benefit from the large number of web services available nowadays on the Internet. This paper presents a practical tool - called rMatcher - to measure the similarity of semantic web services in order to suggest to its user the best ones meeting his requirements. The tool has been developed and experimented on semantic web services described using the OWL-S language.

An Adaptive Scrum Model for Developing Disease Registries.

This paper presents an adaptive model for developing disease registries. The proposed model is based on the Scrum methodology. It can be used to draw a road map to identify priorities, inputs, outputs, team members and exchanges for all tasks required to develop disease registries. Our model has been applied to real cases from several Tunisian hospitals where it has improved the efficiency of the team members. The developed disease registries are currently used in Tunisia. They allow medical researchers to identify origins of diseases, establish new protocols, perform surveys and compute morbidity.