Modifications of the responses of barrel field neurons to vibrissal stimulation during theta in the awake and undrugged rat

In partially restrained but awake and undrugged rats, excitatory unit responses of the somatic cortex barrel field to vibrissal stimulation, were recorded in two conditions: during spontaneous episodes of theta and in the absence of this rhythm. Two main variables were considered: a signal-to-noise ratio and an index of the "afferent inhibition". Both measures were extracted from peristimulus time histograms. "Theta effects" were characterized by an increase in signal-to-noise ratio and afferent inhibition. They were most important in neurons located in infragranular layers of the cortex; they went in the same direction but only approached significance in supragranular neurons; neurons of the granular layer were not affected. Spontaneous unit activity and latencies were not modified in any group. These data were obtained during a preliminary step of a sensory-sensory conditioning procedure which in some cases modified the receptive field of the neurons. Theta effects were less marked in future "conditioned" than in future non-conditioned neurons but this was probably due to the fact that conditioned neurons had significantly higher signal-to-noise ratio and afferent inhibition. The origin of these "theta effects", hippocampal versus non-hippocampal, and their functional significance, relation to selective attention, are discussed.     

Prevalence of Middle East Respiratory Syndrome Coronavirus in Dromedary Camels,Tunisia

Free-roaming camels, especially those crossing national borders, pose a high risk for spreading Middle East respiratory syndrome coronavirus (MERS-CoV). To prevent outbreaks, active surveillance is necessary. We found that a high percentage of dromedaries in Tunisia are MERS-CoV seropositive (80.4%) or actively infected (19.8%), indicating extensive MERS-CoV circulation in Northern Africa.     

Cholangite tuberculeuse simulant une maladie de Caroli : difficultés diagnostiques

Abstract

The liver and the bile ducts represent an exceptional location of tuberculosis. The clinical symptomatology is not specific.We describe three aspects macronodular, micronodular and canalicular which are the rarest.

Purpose

Precise the diagnostic difficulties of this entity insisting on the clinical, biological and morphological signs.

Case report

We report the case of 70 year old man without medical history, admitted for a clinicobiological cholangitis syndrome evolving in a context of impaired general condition. Acute cholecystitis was documented by ultrasound with a moderate dilatationof the common hepatic duct. The bili-MRI showed a dilation of the left intrahepatic bile ducts suggestive of Caroli’s disease. A bi-segmentectomy were performed. Histological examination finds a hepatic tuberculosis and infirm the diagnosis of Caroli’s disease.

Conclusion

Tuberculous cholangitis is rare and poses a diagnostic problem. It can simulate a Caroli disease leading to an unnecessary liver resection. Percutaneous liver biopsy can help to rectify the diagnosis for TBC.     

Endo/exo-proteolysis in neoplastic progression and metastasis

Biological control of individual cells, organs, and organisms is achieved through interplay of a host of specific interactions that involve various peptidic molecules as modulators or effectors. In tumor cells, these processes may result in uncontrolled growth as a consequence of autocrine and/or paracrine actions. In recent years, growing evidence has accumulated for the important role of proprotein convertases (PCs) and peptide -amidation enzymes in these processes. The widespread belief that these enzymes are involved in the major features of tumor progression, namely, invasiveness and metastasis, has taken place because of their capacity to process and activate many protein precursors involved in the neoplastic progression and metastasis. This includes degrading extracellular matrix proteases, growth promoting factors, and adhesion molecules. Usually, when the processing of these precursor proteins is achieved by one or more of the known PC family members within the general motif (K/R)-(X)_n-(K/R), where n=0, 2, 4, or 6, and X, any amino acid except Cys, the accomplishment of the maturation of these molecules is attained by various posttranslational modifications, including the carboxy-terminal -amidation. This review article summarizes recent findings on the role of these enzymatic systems in multiple cellular functions that impact on the invasive/metastatic potential of cancer cells and highlight the potential use of their inhibitors in the treatment of multiple cancers.     

Potter's reno-facial syndrome

Potter's reno-facial syndrome is a rare innate abnormality. We bring 4 observations repertoried at the maternity of military hospital of Tunis over a period of 6 years (1997 - 2002). The purpose of our work is to determine after a review of the literature the echographic and foetopathologic characteristics, and the forecast of this syndrome. The frequency of the bilateral renale agenesis is of 0.27 per thousand. Positive diagnosis bases essentially on the ultrasound of the 2th, or the 3-th trimester. The signs of appeal are essentially the oligoamnios associated to an hypotrophy. The caryotype is systematic to eliminate an associeted chromosomic abnormality. Foetopathologic exam is usefull for the diagnosis. Main abnormality except the urinary pathology is the lung hypoplasia. Therapeutic interruption of the pregnancy in this situation not compatible with the extra-uterine life., only type IV authorize the development of the pregnancy according to echographic data and of foetal urinaire biochemistry. We insist on the early practice of the morphological ultrasound between 20 - 22 weeks for the diagnosis of foetal abnormalities and the place of the genetic advice in association with the geneticist in the coverage of the couple.     

Infantile Blount's disease treated by hemiplateau elevation and epiphyseal distraction using a specific external fixator: preliminary report

The treatment of infantile Blount's disease remains controversial. The progressive development of epiphysiodesis of the medial tibial physis induced a complex deformity of the lower limb such as severe genu varum, joint incongruity, torsion instability and leg length discrepancy with major functional consequences. Nine knees on eight children (average age was 7 years and 2 months) were treated by a one-time procedure using a specific external fixator that combined elevation of the medial tibial plateau, axial correction in the valgus, complete sterilization of the upper tibial growth cartilage, leg lengthening anticipation and de-rotation if necessary. Magnetic resonance imaging was useful to describe the deformity and to prepare for surgery. Corrections were progressively obtained through the physis plan by means of short incisions and the use of a specific external fixator. The primary results at an average of 24 months were good with a low rate of complications but final evaluation will be conducted at the end of the children's growth period.