Planifier un sevrage aux glucocorticoïdes: stratégie diagnostique et thérapeutique [How to plan glucocorticoid withdrawal: diagnostic and therapeutic strategies]

Glucocorticoïds are widely used in medicine and associated with numerous complications. Whenever possible, dosage reduction or treatment withdrawal should be considered as soon as possible depending on the underlying disease being treated. Administration of glucocorticoids induces a physiologic negative feed-back on the hypothalamic-pituitary-adrenal (HPA) axis and three clinical situations can be distinguished during treatment withdrawal: reactivation of the disease for which the glucocorticoids were prescribed, acute adrenal insufficiency and steroid withdrawal syndrome. Acute adrenal insufficiency is a feared complication but probably rare. It is usually seen during stress situations and can be observed long after steroid withdrawal. There is no good predictive marker to anticipate acute adrenal insufficiency and clinical evaluation of the patient remains a key element in its diagnosis. If adrenal insufficiency is suspected, HPA suppression can be assessed with dynamic tests. During stress situation, steroid administration is then recommended depending on the severity of the stress.

Two mechanisms of caspase 9 processing in double-stranded RNA- and virus-triggered apoptosis.

Viral double-stranded RNA (dsRNA) is a ubiquitous intracellular "alert signal" used by cells to detect viral infection and to mount anti-viral responses. DsRNA triggers a rapid (complete within 2-4 h) apoptosis in the highly-susceptible HeLa cell line. Here, we demonstrate that the apical event in this apoptotic cascade is the activation of procaspase 8. Downstream of caspase 8, the apoptotic signaling cascade bifurcates into a mitochondria-independent caspase 8/caspase 3 arm and a mitochondria-dependent, caspase 8/Bid/Bax/Bak/cytochrome c arm. Both arms impinge upon, and activate, procaspase 9 via two different cleavage sites within the procaspase 9 molecule (D330 and D315, respectively). This is the first in vivo demonstration that the "effector" caspase 3 plays an "initiator" role in the regulation of caspase 9. The dsRNA-induced apoptosis is potentiated by the inhibition of protein synthesis, whose role is to accelerate the execution of all apoptosis steps downstream of, and including, the activation of caspase 8. Thus, efficient apoptosis in response to viral dsRNA results from the co-operation of the two major apical caspases (8 and 9) and the dsRNA-activated protein kinase R (PKR)/ribonuclease L (RNase L) system that is essential for the inhibition of protein synthesis in response to viral infection.

Comparison of three commercially available radio frequency coils for human brain imaging at 3 Tesla.

OBJECTIVE: To evaluate a transverse electromagnetic (TEM), a circularly polarized (CP) (birdcage), and a 12-channel phased array head coil at the clinical field strength of B0 = 3T in terms of signal-to-noise ratio (SNR), signal homogeneity, and maps of the effective flip angle alpha. MATERIALS AND METHODS: SNR measurements were performed on low flip angle gradient echo images. In addition, flip angle maps were generated for alpha(nominal) = 30 degrees using the double angle method. These evaluation steps were performed on phantom and human brain data acquired with each coil. Moreover, the signal intensity variation was computed for phantom data using five different regions of interest. RESULTS: In terms of SNR, the TEM coil performs slightly better than the CP coil, but is second to the smaller 12-channel coil for human data. As expected, both the TEM and the CP coils show superior image intensity homogeneity than the 12-channel coil, and achieve larger mean effective flip angles than the combination of body and 12-channel coil with reduced radio frequency power deposition. CONCLUSION: At 3T the benefits of TEM coil design over conventional lumped element(s) coil design start to emerge, though the phased array coil retains an advantage with respect to SNR performance.

Optimisation of an asymmetric polymerase chain reaction assay for the amplification of single-stranded DNA from Wuchereria bancrofti for electrochemical detection

Single-stranded DNA (ssDNA) is a prerequisite for electrochemical sensor-based detection of parasite DNA and other diagnostic applications. To achieve this detection, an asymmetric polymerase chain reaction method was optimised. This method facilitates amplification of ssDNA from the human lymphatic filarial parasite Wuchereria bancrofti. This procedure produced ssDNA fragments of 188 bp in a single step when primer pairs (forward and reverse) were used at a 100:1 molar ratio in the presence of double-stranded template DNA. The ssDNA thus produced was suitable for immobilisation as probe onto the surface of an Indium tin oxide electrode and hybridisation in a system for sequence-specific electrochemical detection of W. bancrofti. The hybridisation of the ssDNA probe and target ssDNA led to considerable decreases in both the anodic and the cathodic currents of the system's redox couple compared with the unhybridised DNA and could be detected via cyclic voltammetry. This method is reproducible and avoids many of the difficulties encountered by conventional methods of filarial parasite DNA detection; thus, it has potential in xenomonitoring.

Performance of diagnostic biomarkers in predicting liver fibrosis among hepatitis C virus-infected Egyptian children

The aim of the present study was to identify specific markers that mirror liver fibrosis progression as an alternative to biopsy when biopsy is contraindicated, especially in children. After liver biopsies were performed, serum samples from 30 hepatitis C virus (HCV) paediatric patients (8-14 years) were analysed and compared with samples from 30 healthy subjects. All subjects were tested for the presence of serum anti-HCV antibodies. Direct biomarkers for liver fibrosis, including transforming growth factor-β1, tissue inhibitor of matrix metalloproteinase-1 (TIMP-1), hyaluronic acid (HA), procollagen type III amino-terminal peptide (PIIINP) and osteopontin (OPN), were measured. The indirect biomarkers aspartate and alanine aminotransferases, albumin and bilirubin were also tested. The results revealed a significant increase in the serum marker levels in HCV-infected children compared with the healthy group, whereas albumin levels exhibited a significant decrease. Significantly higher levels of PIIINP, TIMP-1, OPN and HA were detected in HCV-infected children with moderate to severe fibrosis compared with children with mild fibrosis (p < 0.05). The diagnostic accuracy of these direct biomarkers, represented by sensitivity, specificity and positive predictive value, emphasises the utility of PIIINP, TIMP-1, OPN and HA as indicators of liver fibrosis among HCV-infected children.

A rapid diagnostic test for schistosomiasis mansoni

This article presents an improvement to the Kato-Katz (KK) method, making it faster and more efficient for the visualisation of fertile eggs in stool samples. This modified KK method uses sodium acetate formalin as a fixative and reveals the intensity of infection in less than 1 h, reducing the diagnostic time without increasing the cost. This modified method may contribute to future epidemiological studies in both hospitals and the field due to its rapid and precise diagnostic, which allow for immediate treatment.

Safety and immunomodulatory effects of three probiotic strains isolated from the feces of breast-fed infants in healthy adults: SETOPROB study.

We previously described the isolation and characterization of three probiotic strains from the feces of exclusively breast-fed newborn infants: Lactobacillus paracasei CNCM I-4034, Bifidobacterium breve CNCM I-4035 and Lactobacillus rhamnosus CNCM I-4036. These strains were shown to adhere to intestinal mucus in vitro, to be sensitive to antibiotics and to resist biliary salts and low pH. In the present study, a multicenter, randomized, double-blind, placebo-controlled trial with 100 healthy volunteers in three Spanish cities was carried out to evaluate the tolerance, safety, gut colonization and immunomodulatory effects of these three probiotics. Volunteers underwent a 15-day washout period, after which they were randomly divided into 5 groups that received daily a placebo, a capsule containing one of the 3 strains or a capsule containing a mixture of two strains for 30 days. The intervention was followed by another 15-day washout period. Patients did not consume fermented milk for the entire duration of the study. Gastrointestinal symptoms, defecation frequency and stool consistency were not altered by probiotic intake. No relevant changes in blood and serum, as well as no adverse events occurred during or after treatment. Probiotic administration slightly modified bacterial populations in the volunteers' feces. Intestinal persistence occurred in volunteers who received L. rhamnosus CNCM I-4036. Administration of B. breve CNCM I-4035 resulted in a significant increase in fecal secretory IgA content. IL-4 and IL-10 increased, whereas IL-12 decreased in the serum of volunteers treated with any of the three strains. These results demonstrate that the consumption of these three bacterial strains was safe and exerted varying degrees of immunomodulatory effects.

Meta-analysis of diagnostic test accuracy in neurosurgical practice.

Comparative effectiveness research (CER) allows evidence to be evaluated on the effectiveness, benefits, and detriments of management options, diagnostic tests, or ways to deliver health care. This process can be achieved in different ways, such as with well-designed randomized controlled trials or by meta-analyses. Several medical subspecialties are increasingly using CER, but CER remains underused by the neurosurgical community. Meta-analysis is a highly accurate method that permits results from multiple well-designed research studies to be quantitatively compared. Meta-analysis can be performed in many settings, such as the evaluation of treatment or of a diagnostic test or prognostic factor. Meta-analyses of randomized controlled treatment trials are well known, but there is a paucity of papers describing the ways to perform a meta-analysis of a diagnostic test. The aim of this paper is to improve neurosurgeons' familiarity with the meta-analysis of diagnostic test accuracy by describing and detailing each stage leading to publication.

Paralysie faciale: diagnostic et prise en charge [Diagnosis and management of facial paralysis]

Facial palsy is an unusual pathology that requires standard investigations and management. A clinical overview of the current attitudes is suggested to the general practitioners in order to help them in initiating the adequate investigations and treatment before referring the patient to a specialist.

Localization of peroxisome proliferator-activated receptor alpha (PPARα) and N-acyl phosphatidylethanolamine phospholipase D (NAPE-PLD) in cells expressing the Ca(2+)-binding proteins calbindin, calretinin, and parvalbumin in the adult rat hippocampus.

The N-acylethanolamines (NAEs), oleoylethanolamide (OEA) and palmithylethanolamide (PEA) are known to be endogenous ligands of PPARα receptors, and their presence requires the activation of a specific phospholipase D (NAPE-PLD) associated with intracellular Ca(2+) fluxes. Thus, the identification of a specific population of NAPE-PLD/PPARα-containing neurons that express selective Ca(2+)-binding proteins (CaBPs) may provide a neuroanatomical basis to better understand the PPARα system in the brain. For this purpose, we used double-label immunofluorescence and confocal laser scanning microscopy for the characterization of the co-existence of NAPE-PLD/PPARα and the CaBPs calbindin D28k, calretinin and parvalbumin in the rat hippocampus. PPARα expression was specifically localized in the cell nucleus and, occasionally, in the cytoplasm of the principal cells (dentate granular and CA pyramidal cells) and some non-principal cells of the hippocampus. PPARα was expressed in the calbindin-containing cells of the granular cell layer of the dentate gyrus (DG) and the SP of CA1. These principal PPARα(+)/calbindin(+) cells were closely surrounded by NAPE-PLD(+) fiber varicosities. No pyramidal PPARα(+)/calbindin(+) cells were detected in CA3. Most cells containing parvalbumin expressed both NAPE-PLD and PPARα in the principal layers of the DG and CA1/3. A small number of cells containing PPARα and calretinin was found along the hippocampus. Scattered NAPE-PLD(+)/calretinin(+) cells were specifically detected in CA3. NAPE-PLD(+) puncta surrounded the calretinin(+) cells localized in the principal cells of the DG and CA1. The identification of the hippocampal subpopulations of NAPE-PLD/PPARα-containing neurons that express selective CaBPs should be considered when analyzing the role of NAEs/PPARα-signaling system in the regulation of hippocampal functions.

Automated four-color interphase fluorescence in situ hybridization approach for the simultaneous detection of specific aneuploidies of diagnostic and prognostic significance in high hyperdiploid acute lymphoblastic leukemia.

In high hyperdiploid acute lymphoblastic leukemia (ALL), the concurrence of specific trisomies confers a more favorable outcome than hyperdiploidy alone. Interphase fluorescence in situ hybridization (FISH) complements conventional cytogenetics (CC) through its sensitivity and ability to detect chromosome aberrations in nondividing cells. To overcome the limits of manual I-FISH, we developed an automated four-color I-FISH approach and assessed its ability to detect concurrent aneuploidies in ALL. I-FISH was performed using centromeric probes for chromosomes 4, 6, 10, and 17. Parameters established for nucleus selection and signal detection were evaluated. Cutoff values were determined. Combinations of aneuploidies were considered relevant when each aneuploidy was individually significant. Results obtained in 10 patient samples were compared with those obtained with CC. Various combinations of aneuploidies were identified. All clones detected by CC were observed also by I-FISH, and I-FISH revealed numerous additional abnormal clones in all patients, ranging from < or =1% to 31.6% of cells analyzed. We conclude that four-color automated I-FISH permits the identification of concurrent aneuploidies of potential prognostic significance. Large numbers of cells can be analyzed rapidly. The large number of nuclei scored revealed a high level of chromosome variability both at diagnosis and relapse, the prognostic significance of which is of considerable clinical interest and merits further evaluation.