[Candida dubliniensis: Identification methods and epidemiologic implication]. / Candida dubliniensis : méthodes d'identification et implications épidémiologiques.

Candida dubliniensis was recently described (1995) associated with oral candidiasis in HIV-positive patients. This organism is very closely related to the pathogenic human yeast, Candida albicans, and share a great number of phenotypic and genotypic characters. This great similarity limits the discrimination between these two species. Several phenotypic and molecular methods were developed. The phenotypic methods are simply used in routine discrimination between these two species and depend on the growth at high temperature, sugar assimilation, growth on special mediums and chlamydospore production…; but these methods are insensitive in discrimination between these two species. The molecular biology methods are highly reliable and able to confirm rapidly the identification of this species. In this article, we will review the various studies run out concerning the methods deployed for the identification of C. dubliniensis as well as the epidemiological implication of this new pathogen.

Candida dubliniensis: first identification in Sfax Hospital, Tunisia.

Candida dubliniensis, a newly described fungal pathogen associated mainly to immunocompromised host's infection, is phenotypically closely related to C. albicans. In this study, we report for the first time, isolation and identification, in Tunisia, of 14 isolates of C. dubliniensis from 12 human immunodeficiency virus-negative patients hospitalised in the intensive care unit (ICU) at Habib Bourguiba Sfax Hospital. Our study was firstly based on the failure to grow at 45 degrees C. This presumptive identification was completed by other tests: chlamydospore production, culture on Candiselect4 (Bio-Rad) and the commercial test Bichro-Dubli fumouze, which specifically identify C. dubliniensis. The confirmation of the discrimination between both species was performed by PCR, targeting the hyphal wall protein (HWP1) gene. The recovery of C. dublinensis by routine laboratory diagnosis is recommended for elucidating the epidemiology of this novel pathogen.

[The solid pseudopapillary tumor of pancreas: two cases and literature review]. / Tumeurs pseudopapillaires et solides du pancréas: deux observations et revue de la littérature.

Solid pseudopapillary tumor (SPT) of the pancreas is a rare exocrine pancreatic tumor behaving in a low-grade fashion, with limited local invasion risk and a rare metastatic evolution. We report SPT in two young females, revealed by abdominal pain and an epigastric mass. The diagnosis of a cystic tumor was based on abdominal ultrasound and CT data in the first case and on MRI in the second. A distal pancreatectomy and splenectomy were successfully performed in the first case and a central pancreatectomy in the second. Histological study confirmed the diagnosis of SPT of the pancreas.

[Laparoscopic treatment of perforated duodenal ulcer: 84 cases in Tunisia]. / Traitement laparoscopique des ulcères duodénaux perforés: 84 cas en Tunisie.

INTRODUCTION: The purpose of this study was to evaluate the feasibility, efficacy and safety of the laporascopic treatment of perforated duodenal ulcer. METHODS: This retrospective study included patients who underwent laparoscopic treatment of perforated duodenal ulcer during the seven-year period from 2001 to 2007. The procedure included direct suture of the perforated ulcer followed by peritoneal lavage. All patients received medical treatment including Helicobacter pylori eradication and proton pump inhibitor therapy. RESULTS: A total of 84 patients underwent laparoscopic surgery for perforated duodenal ulcer during the study period. There were 81 men and 3 women with a mean age of 28 years. Laparoscopic examination confirmed diagnosis of perforated duodenal ulcer in all cases. Direct suture of the ulcer was successful in 72 cases. In the remaining 12 cases conversion to open surgery was necessary due to difficulty in achieving peritoneal lavage in 6 cases, ulcer size and edge friability in 5, and septic shock in one. The mean duration of the procedure was 95 minutes (range, 60 to 180 minutes). The mean postoperative complication rate was 15.4%. Complications included peritonintis in one case and digestive fistula in one. There were no postoperative deaths. All patients were re-examined after 25 months. Two patients presented recurrences after the laparoscopic treatment and required tri-therapy. CONCLUSION: Laparoscopic suture of perforated duodenal ulcer is safe and effective. It avoids the need for laparotomy that is associated with a risk for septic and parietal complications. Since medical treatment is effective for ulcerous disease, there are currently no indications for radical treatment.

Effective implementation of time-frequency matched filter with adapted pre and postprocessing for data-dependent detection of newborn seizures.

Neonatal EEG seizures often manifest as nonstationary and multicomponent signals, necessitating analysis in the time-frequency (TF) domain. This paper presents a novel neonatal seizure detector based on effective implementation of the TF matched filter. In the detection process, the TF signatures of EEG seizure are extracted to construct the TF templates used by the matched filter. Matching pursuit (MP) decomposition and narrowband filtering are proposed for the reduction of artifacts prior to seizure detection. Geometrical correlation is used to consolidate the multichannel detections and to reduce the number of false detections due to remnant artifacts. A data-dependent threshold is defined for the classification of EEG. Using 30 newborn EEG records with seizures, the classification process yielded an overall detection accuracy of 92.4% with good detection rate (GDR) of 84.8% and false detection rate of 0.36FD/h. Better detection performance (accuracy >95%) was recorded for relatively long EEG records with short seizure events.

Accelerometer-based fetal movement detection.

Monitoring fetal wellbeing is a compelling problem in modern obstetrics. Clinicians have become increasingly aware of the link between fetal activity (movement), well-being, and later developmental outcome. We have recently developed an ambulatory accelerometer-based fetal activity monitor (AFAM) to record 24-hour fetal movement. Using this system, we aim at developing signal processing methods to automatically detect and quantitatively characterize fetal movements. The first step in this direction is to test the performance of the accelerometer in detecting fetal movement against real-time ultrasound imaging (taken as the gold standard). This paper reports first results of this performance analysis.

Kalman filter-based time-varying cortical connectivity analysis of newborn EEG.

Multivariate Granger causality in the time-frequency domain as a representation of time-varying cortical connectivity in the brain has been investigated for the adult case. This is, however, not the case in newborns as the nature of the transient changes in the newborn EEG is different from that of adults. This paper aims to evaluate the performance of the time-varying versions of the two popular Granger causality measures, namely Partial Directed Coherence (PDC) and direct Directed Transfer Function (dDTF). The parameters of the time-varying AR, that models the inter-channel interactions, are estimated using Dual Extended Kalman Filter (DEKF) as it accounts for both non-stationarity and non-linearity behaviors of the EEG. Using simulated data, we show that fast changing cortical connectivity between channels can be measured more accurately using the time-varying PDC. The performance of the time-varying PDC is also tested on a neonatal EEG exhibiting seizure.

[Pancreatic hydatid cyst: an exceptional localization]. / Kyste hydatique du pancréas: une localisation exceptionnelle.

Pancreatic hydatid cysts are rare. They account for 1% of all hydatid cysts and are extremely rare in children. This may explain the problems diagnosing this condition. We report on a new case of pancreatic hydatic cyst in an 11-year-old girl who was admitted with a previous history of abdominal pain and jaundice. We discuss the diagnostic features of pancreatic hydatid cyst and therapeutic modalities.

Evaluation of nested and real-time PCR assays in the diagnosis of candidaemia.

Polymerase chain reaction (PCR) assays have a very low theoretical detection threshold and are therefore advocated for the diagnosis of fungaemia. However, their effectiveness in this respect remains to be assessed. This study compared real-time PCR (Can-G) and nested PCR assays with blood culture for the diagnosis of Candida spp. bloodstream infections. A total of 200 clinical blood samples obtained from 110 patients at risk for developing a systemic fungal infection, hospitalized in the University Hospital of Sfax (Tunisia), were submitted to testing by culture, nested PCR and real-time PCR. Blood culture was positive in 36 patients. When compared with culture, the Can-G assay (81% sensitivity, 96% specificity) performed better than the nested PCR assay (86% sensitivity, 54% specificity). The real-time PCR assay, which avoids both the contamination hazard with amplicons that may cause false-positive results and the use of time-consuming post-PCR steps, appears more suitable than the nested PCR assay for the laboratory diagnosis of Candida spp. bloodstream infections. In this study, real-time PCR did not enhance the diagnostic sensitivity for Candida spp. bloodstream infections compared with conventional blood culture; however, it may lead to earlier implementation of an adequately targeted antifungal treatment.

Detection of neonatal EEG seizure using multichannel matching pursuit.

It is unusual for a newborn to have the classic "tonic-clonic" seizure experienced by adults and older children. Signs of seizure in newborns are either subtle or may become clinically silent. Therefore, the electroencephalogram (EEG) is becoming the most reliable tool for detecting neonatal seizure. Being non-stationary and multicomponent, EEG signals are suitably analyzed using time-frequency (TF) based methods. In this paper, we present a seizure detection method using a new measure based on the matching pursuit (MP) decomposition of EEG data. Signals are represented in the TF domain where seizure structural characteristics are extracted to form a new coherent TF dictionary to be used in the MP decomposition. A new approach to set data-dependent thresholds, used in the seizure detection process, is proposed. To enhance the performance of the detector, the concept of areas of incidence is utilized to determine the geometrical correlation between EEG recording channels.

Multichannel-based newborn EEG seizure detection using time-frequency matched filter.

In recent years, much effort has been made toward developing computerized methods to detect seizures. In adults, the clinical signs of seizures are well defined and easily recognizable. But in newborns, these signs are either subtle or completely absent. For this reason, the electroencephalogram (EEG) has been the most dependable tool used for detecting seizures in newborns. Considering the non-stationary and multicomponent nature of the EEG signals, time-frequency (TF) based methods were found to be very suitable for the analysis of such signals. Using TF representation of EEG signals allows extracting TF signatures that are characteristic of EEG seizures. In this paper we present a TF method for newborn EEG seizure detection using a TF matched filter. The threshold used to distinguish between seizure and non-seizure is data-dependent and is set using the EEG background. Multichannel geometrical correlation, based on a concept of incidence matrix, was utilized to further enhance the performance of the detector.