Polarized expression of cystic fibrosis transmembrane conductance regulator and associated epithelial proteins during the regeneration of human airway surface epithelium in three-dimensional culture

We have previously shown that, in normal human airway tissue, localization of the cystic fibrosis transmembrane conductance regulator (CFTR) can be affected by epithelial maturation, polarity, and differentiation and that CFTR trafficking and apical localization depend on the integrity of the airway epithelium. In this study, we addressed the question of whether the three-dimensional (3-D) organization of adult human airway epithelial cells in suspension culture under rotation, leading to spheroid-like structures, could mimic the in vivo phenomenon of differentiation and polarization. The kinetics of the differentiation, polarity, and formation of the CFTR-ZO-1-ezrin complex was analyzed by transmission, scanning, and immunofluorescence microscopy. Functional activity of the airway surface epithelium was assessed by monitoring the degree of cAMP-stimulated chloride efflux from cultured cells. Our results show that after the initial step of dedifferentiation, characterized by a loss of ciliated cells and disappearance of epithelial subapical CFTR-ezrin-ZO-1 complex, the isolated cells formed 3-D spheroid structures within 24 hours. After 15 days, progressive ciliogenesis was observed and secretory cells could be identified. After 35 days of 3-D culture, ZO-1, CFTR, ezrin, and CD59 were apically or subapically located, and well-differentiated secretory and ciliated cells were identified. CFTR functionality was assessed by analyzing the Cl(-) secretion after amiloride and forskolin perfusion. After 35 days of culture of spheroids in suspension, a significant increase in Cl(-) efflux was observed in well-differentiated ciliated cells.     

Retrograde trans-synaptic transfer of green fluorescent protein allows the genetic mapping of neuronal circuits in transgenic mice

The function of the nervous system is a consequence of the intricate synaptic connectivity of its neurons. Our understanding of these highly complex networks has profited enormously from methods used over the past two decades that are based on the mechanical injection of tracer molecules into brain regions. We have developed a genetic system for the mapping of synaptic connections during development of the mammalian central nervous system and in the mature brain. It is based on the transsynaptic transfer of green fluorescent protein (GFP) in the brains of mice using a fusion protein with a nontoxic fragment of tetanus toxin (TTC) expressed in defined neurons. These transgenic mice allowed us to visualize neurons, at single-cell resolution, that are in synaptic contact by the detection of GFP in interconnected circuits. Targeted genetic expression with a specific promoter permitted us to transfer GFP to defined subsets of neurons and brain regions. GFP-TTC is coexpressed with a lacZ reporter gene to discriminate neurons that produce the tracer from cells that have acquired it transneuronally. The marker shows selective transfer in the retrograde direction. We have used electron microscopic detection of GFP to define the ultrastructural features of the system. Our work opens up a range of possibilities for brain slice and in vivo studies taking advantage of the fluorescence of GFP. We point the way toward the use of powerful multiphoton technology and set the stage for the transsynaptic transfer of other proteins in the brains of mice.     

Estimation of Ochratoxin A in human blood of healthy Tunisian population

Human exposure to Ochratoxin A (OTA) has been investigated in many Mediterranean countries, where OTA was found with a higher frequency in foodstuffs and blood samples. The aim of this study was to assess OTA concentrations in human blood serum in Tunisia and to evaluate the impact of several factors (age, origin, sex) on these prevalence reference values. One hundred and seven blood serum samples from healthy subjects were analyzed using a solid-phase extraction linked to a high-performance liquid chromatography (HPLC) method. OTA values ranged from 0 to 3.43 ng/mL with a mean value of 0.49±0.67 ng/mL. OTA levels were higher in the Sahal group. Our results reflect OTA concentration previously detected for human blood in Tunisia. Origin, but not age and sex, may affect the OTA reference values.     

Effects of Heavy Metals Artificial Contamination on Porcellio laevis (Latreille, 1804) (Crustacea: Isopoda: Oniscidea)

Bulletin of Environmental Contamination and Toxicology - This study aimed at determining the competition of cadmium (Cd), lead (Pb), zinc (Zn) and copper (Cu) on their assimilation, on the food...     

Psychometric evaluation of the Moroccan version of the Bath Ankylosing Spondylitis Functional Index (BASFI) and Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) for use in patients with ankylosing spondylitis

The objectives of this study are to translate, adapt in the Moroccan cultural context, and validate in patients with ankylosing spondylitis (AS) the Bath Ankylosing Spondylitis Functional Index (BASFI) and Bath Ankylosing Spondylitis Disease Activity Index (BASDAI). The cross-cultural adaptation of the BASFI and BASDAI was obtained in accordance with the guidelines for translation of the health status measures. Eighty-five patients with AS were included in the study. The test–retest reliability and the internal consistency were analyzed, and both questionnaires were assessed for external construct validity. Structural validity was analyzed with correlation matrix. Twenty-four-hour test–retest reliability was good: BASFI intraclass correlation coefficient (ICC) = 0.96 (confidence interval (CI) at 95%, 0.93–0.97), BASDAI ICC = 0.93 (CI at 95%, 0.90–0.95). Cronbach’s alpha was 0.90 for the BASFI and 0.86 for BASDAI. The construct validity of the instruments was evaluated. The BASFI showed a strong validity when correlating its results with Schober’s test (r = −0.56), occipital wall distance (r = 0.46), chest expansion (r = −0.46), BASDAI (r = 0.54), Bath Ankylosing Spondylitis Metrology Index (r = 0.70), Bath Ankylosing Spondylitis Global Score (BAS-G; r = 0.58), Bath Ankylosing Spondylitis Radiology Index (r = 0.61), and the radiological changes in sacroiliac joints (r = 0.54). A good correlation was observed between the BASDAI and the spinal pain (r = 0.53), the number of nocturnal awakenings (r = 0.57), the morning stiffness (r = 0.65), the enthesic index (r = 0.47), the BAS-G (r = 0.53), the BASFI (r = 0.54), and the erythrocyte sedimentation rate (r = 0.41; for all p < 0.001). The correlation matrix showed an intermediate correlation between items. The Moroccan version of the BASFI and the BASDAI showed adequate reliability and validity. These instruments can be used in the clinical evaluation of Moroccan and Arabic-speaking patients with AS.     

Predictive factors of septic shock and mortality in neutropenic patients

Neutropenia is a major risk factor for developing a serious infection. Bacteremia still causes significant mortality among neutropenic patients with cancer. The purpose of this study was to identify risk factors for septic shock and for mortality in neutropenic patients with leukemia and bacteremia. Consecutive samples from 20 patients with acute myeloid leukemia and bacteremia were studied during a 1 year period (January-December 2003). All patients received empirical antibiotic therapies for febrile episodes using ceftazidime plus amikacin. About 110 neutropenic febrile episodes were noted: clinically documented 14.54%, microbiologically documented 16.36% and fever of unknown origin 69.09%. Gram-negative organism caused eight febrile episodes: Pseudomonas (5), Klebsiella (3). Gram-positive organism caused 10 episodes: Staphylococcus (6), Streptococci (2), Enterococci (2). Pulmonary infection accounted for 25% of clinically documented infections. About 14 of the 110 febrile episodes were associated with septic shock causing mortality in 7 patients. In a univariate analysis variables associated with septic shock were: pulmonary infection (OR = 17, p = 0.001), serum bicarbonate < 17 mmol/l (OR = 68, p < 0.001) and serum lactate >3 mmol/l (OR = 62, p < 0.001). Variables associated with mortality were: pulmonary infection (OR = 83, p < 0.001) and serum bicarbonate < 17 mmol/l (OR = 61, p < 0.001). In a multivariate analysis two variables were associated with septic shock: pulmonary infection (OR = 5, p = 0.043) and serum lactate >3 mmol/l (OR = 10, p = 0.003). An elevated serum lactate (>3 mmol/l) and low serum bicarbonate ( < 17 mmol/l) at the onset of bacteremia are useful biomarkers in predicting septic shock and mortality in neutropenic patients.