Biocatalyst immobilization on magnetic nano-architectures for potential applications in condensation reactions.

In this review article, a perspective on the immobilization of various hydrolytic enzymes onto magnetic nanoparticles for synthetic organic chemistry applications is presented. After a first part giving short overview on nanomagnetism and highlighting advantages and disadvantages of immobilizing enzymes on magnetic nanoparticles (MNPs), the most important hydrolytic enzymes and their applications were summarized. A section reviewing the immobilization techniques with a particular focus on supporting enzymes on MNPs introduces the reader to the final chapter describing synthetic organic chemistry applications of small molecules (flavour esters) and polymers (polyesters and polyamides). Finally, the conclusion and perspective section gives the author's personal view on further research discussing the new idea of a synergistic rational design of the magnetic and biocatalytic component to produce novel magnetic nano-architectures.

Navigating the multifaceted intricacies of the Na+-Cl- cotransporter, a highly regulated key effector in the control of hydromineral homeostasis.

The Na+-Cl- cotransporter (NCC; SLC12A3) is a highly regulated integral membrane protein that is known to exist as three splice variants in primates. Its primary role in the kidney is to mediate the cosymport of Na+ and Cl- across the apical membrane of the distal convoluted tubule. Through this role and the involvement of other ion transport systems, NCC allows the systemic circulation to reclaim a fraction of the ultrafiltered Na+, K+, Cl-, and Mg+ loads in exchange for Ca2+ and [Formula: see text]. The physiological relevance of the Na+-Cl- cotransport mechanism in humans is illustrated by several abnormalities that result from NCC inactivation through the administration of thiazides or in the setting of hereditary disorders. The purpose of the present review is to discuss the molecular mechanisms and overall roles of Na+-Cl- cotransport as the main topics of interest. On reading the narrative proposed, one will realize that the knowledge gained in regard to these themes will continue to progress unrelentingly no matter how refined it has now become.

Multiple Facets and Roles of Na+-K+-Cl- Cotransport: Mechanisms and Therapeutic Implications.

The Na+-K+-Cl- cotransporters play key physiological and pathophysiological roles by regulating the membrane potential of many cell types and the movement of fluid across a variety of epithelial or endothelial structures. As such, they should soon become invaluable targets for the treatment of various disorders including pain, epilepsy, brain edema, and hypertension. This review highlights the nature of these roles, the mechanisms at play, and the unresolved issues in the field.

Magnetic mesoporous silica nanostructures: investigation of magnetic properties.

Magnetic mesoporous silica (MS) nanocomposites provide the possibility of generating multi-functional objects for application in different technological areas. This paper focuses on the magnetic properties of nanocomposites constituted by spinel iron oxide nanoparticles (magnetic nanoparticles (MNPs), < D > ≈ 8-9 nm) embedded in an MS matrix. The mesoporous structure of the silica matrix and the presence of the nanoparticles inside clearly emerge from transmission electron microscopy (TEM) measurements. Low temperature (5 K) field-dependent magnetization measurements reveal saturation magnetization (MS ) close to bulk value (M S bulk ∼ 90 emu g-1) for both MNPs and MNP/MS nanocomposites, indicating that the presence of silica does not affect the magnetic features of the single MNPs. Moreover, the dependence of the remanent magnetization on field (i.e. δM plots) at low temperature has shown a small but evident decrease of interaction in an MNP/MS sample with respect to MNP samples A m2 Kg-1. Finally, a partial orientation of the easy axis is observed when the MNPs are embedded in the silica matrix.

K+-Cl- cotransporter 1 (KCC1): a housekeeping membrane protein that plays key supplemental roles in hematopoietic and cancer cells.

During the 1970s, a Na+-independent, ouabain-insensitive, N-ethylmaleimide-stimulated K+-Cl- cotransport mechanism was identified in red blood cells for the first time and in a variety of cell types afterward. During and just after the mid-1990s, three closely related isoforms were shown to account for this mechanism. They were termed K+-Cl- cotransporter 1 (KCC1), KCC3, and KCC4 according to the nomenclature of Gillen et al. (1996) who had been the first research group to uncover the molecular identity of a KCC, that is, of KCC1 in rabbit kidney. Since then, KCC1 has been found to be the most widely distributed KCC isoform and considered to act as a housekeeping membrane protein. It has perhaps received less attention than the other isoforms for this reason, but as will be discussed in the following review, there is probably more to KCC1 than meets the eye. In particular, the so-called housekeeping gene also appears to play crucial and specific roles in normal as well as pathological hematopoietic and in cancer cells.

Physiological roles and molecular mechanisms of K+ -Cl- cotransport in the mammalian kidney and cardiovascular system: where are we?

In the early 80s, renal microperfusion studies led to the identification of a basolateral K+ -Cl- cotransport mechanism in the proximal tubule, thick ascending limb of Henle and collecting duct. More than ten years later, this mechanism was found to be accounted for by three different K+ -Cl- cotransporters (KCC1, KCC3 and KCC4) that are differentially distributed along the renal epithelium. Two of these isoforms (KCC1 and KCC3) were also found to be expressed in arterial walls, the myocardium and a variety of neurons. Subsequently, valuable insights have been gained into the molecular and physiological properties of the KCCs in both the mammalian kidney and cardiovascular system. There is now robust evidence indicating that KCC4 sustains distal renal acidification and that KCC3 regulates myogenic tone in resistance vessels. However, progress in understanding the functional significance of these transporters has been slow, probably because each of the KCC isoforms is not identically distributed among species and some of them share common subcellular localizations with other KCC isoforms or sizeable conductive Cl- pathways. In addition, the mechanisms underlying the process of K+ -Cl- cotransport are still ill defined. The present review focuses on the knowledge gained regarding the roles and properties of KCCs in renal and cardiovascular tissues.

Molecular features and physiological roles of K+-Cl- cotransporter 4 (KCC4).

A K+-Cl- cotransport system was documented for the first time during the mid-seventies in sheep and goat red blood cells. It was then described as a Na+-independent and ouabain-insensitive ion carrier that could be stimulated by cell swelling and N-ethylmaleimide (NEM), a thiol-reacting agent. Twenty years later, this system was found to be dispensed by four different isoforms in animal cells. The first one was identified in the expressed sequence tag (EST) database by Gillen et al. based on the assumption that it would be homologous to the Na+-dependent K+-Cl- cotransport system for which the molecular identity had already been uncovered. Not long after, the three other isoforms were once again identified in the EST databank. Among those, KCC4 has generated much interest a few years ago when it was shown to sustain distal renal acidification and hearing development in mouse. As will be seen in this review, many additional roles were ascribed to this isoform, in keeping with its wide distribution in animal species. However, some of them have still not been confirmed through animal models of gene inactivation or overexpression. Along the same line, considerable knowledge has been acquired on the mechanisms by which KCC4 is regulated and the environmental cues to which it is sensitive. Yet, it is inferred to some extent from historical views and extrapolations.

Biochips for Direct Detection and Identification of Bacteria in Blood Culture-Like Conditions.

Bloodstream bacterial infections are life-threatening conditions necessitating prompt medical care. Rapid pathogen identification is essential for early setting of the best anti-infectious therapy. However, the bacterial load in blood samples from patients with bacteremia is too low and under the limit of detection of most methods for direct identification of bacteria. Therefore, a preliminary step enabling the bacterial multiplication is required. To do so, blood cultures still remain the gold standard before bacteremia diagnosis. Bacterial identification is then usually obtained within 24 to 48 hours -at least- after blood sampling. In the present work, the fast and direct identification of bacteria present in blood cultures is completed in less than 12 hours, during bacterial growth, using an antibody microarray coupled to a Surface Plasmon Resonance imager (SPRi). Less than one bacterium (Salmonella enterica serovar Enteritidis) per milliliter of blood sample is successfully detected and identified in blood volumes similar to blood tests collected in clinics (i.e. several milliliters). This proof of concept demonstrates the workability of our method for human samples, despite the highly complex intrinsic nature of unprocessed blood. Our label-free method then opens new perspectives for direct and faster bacterial identification in a larger range of clinical samples.

[Adult intramedullary gliomas]. / Tumeurs gliales intramédullaires de l'adulte : la série du rapport.

OBJECTIVES: Intramedullary gliomas are rare tumors accounting for less than 4% of all primary central nervous system tumors. The aims of this retrospective multicenter study were to assess their natural outcome as well as management. METHODS AND MATERIALS: We studied 332 patients from 1984 to 2011. Histopathological examination revealed 72% ependymomas (94% were low grade tumors), 24% astrocytomas (29% were high grade tumors), 2.4% mixed gliomas and 1.7% oligodendrogliomas. RESULTS: The mean age at diagnosis was 42.4 years for ependymomas, with male predominance, versus 39.6 years for astrocytomas. Pain was the most common initial presentation. In 20% of cases, astrocytomas were biopsied alone, but more than 80% of ependymomas had surgical resection. Radiotherapy and chemotherapy were reserved for malignant tumors, especially if they were ependymomas. The 5-year survival rate was 76.8% for astrocytomas and 94.5% for ependymomas. Histology, functional status prior to surgery, and tumor grade are among the prognostic factors. CONCLUSION: Our study showed that surgical treatment of gliomas is well codified, at least for ependymomas, but adjuvant treatment continues to play a marginal role in the management even in astrocytomas, which are infiltrative tumors.

Fast detection of both O157 and non-O157 shiga-toxin producing Escherichia coli by real-time optical immunoassay.

UNLABELLED: Among bacterial pathogens involved in food-illnesses, seven serogroups (O26, O45, O103, O111, O121, O145 and O157) of Shiga-toxin producing Escherichia coli (STEC), are frequently identified. During such outbreak, and due to the perishable property of most foodstuff, the time laps for the identification of contaminated products and pathogens is thus critical to better circumvent their spread. Traditional detection methods using PCR or culture plating are time consuming and may present some limitations. In this study, we present a multiplexed immunoassay for the optical detection of most commonly enterohemorrhagic E. coli serogroups: O26, O45, O103, O111, O121, O145 and O157:H7 in a single device. The use of Surface Plasmon Resonance imaging not only enabled the label-free analysis of the samples but gave results in a real-time manner. A dedicated protocol was set up for the detection of both low contaminating bacterial concentrations of food samples (5 CFU per 25 g) and postenrichment aliquots. By combining one single device for the detection of O157 and non-O157 STEC in a label-free manner, this rapid approach may have an important economic and societal impact. SIGNIFICANCE AND IMPACT OF THE STUDY: This article presents a simple-to-operate immunoassay for the specific detection of Shiga-toxin producing Escherichia coli (STEC). This approach consists in the on-chip assay detection of viable cells on a specifically designed antibody microarray. By skipping any enrichment step and avoiding the use of labelling agent, this approach based on the Surface Plasmon Resonance imaging of the microarrays turns out to be much faster and more cost effective by comparison with standardized methods.

[A paraneoplastic Sharp syndrome reversible after resection of a benign schwannoma: a paraneoplastic syndrome?]. / Syndrome de Sharp réversible après l'ablation d'un schwannome bénin : un syndrome paranéoplasique ?

Paraneoplastic syndromes commonly occur in malignancies and often precede the first symptoms of the tumor. By definition, paraneoplastic syndromes are only associated with malignancies although some exceptions have been reported, occurring with benign tumors. We report a patient presenting with a clinical and serological Sharp syndrome, followed a few months later by a cervical schwannoma. Curative surgical resection of the mass resulted in a clinical and serological healing from the Sharp syndrome. To our knowledge, this is the first report of a benign schwannoma complicated by a possible paraneoplastic Sharp syndrome.

Hospital washbasin water: risk of Legionella-contaminated aerosol inhalation.

The contamination of aerosols by washbasin water colonized by Legionella in a hospital was evaluated. Aerosol samples were collected by two impingement technologies. Legionella was never detected by culture in all the (aerosol) samples. However, 45% (18/40) of aerosol samples were positive for Legionella spp. by polymerase chain reaction, with measurable concentrations in 10% of samples (4/40). Moreover, immunoassay detected Legionella pneumophila serogroup 1 and L. anisa, and potentially viable bacteria were seen on viability testing. These data suggest that colonized hospital washbasins could represent risks of exposure to Legionella aerosol inhalation, especially by immunocompromised patients.

Contribution of amoebic coculture to recovery of Legionella isolates from respiratory samples: prospective analysis over a period of 32 months.

We evaluated the contribution of amoebic coculture to the recovery of Legionella spp. from 379 respiratory samples. The sensitivity of axenic culture was 42.1%. The combination of axenic culture with amoebic coculture increased the Legionella isolation rate to 47.1%. Amoebic coculture was particularly efficient in isolating Legionella spp. from respiratory samples contaminated with oropharyngeal flora.

Urinary markers of workers chronically exposed to mercury vapor.

The effects of chronic mercury intoxication on urinary markers in workers from northeast Algeria were investigated. Workmen were chosen from highly and moderately mercury-exposed factories, while controls were selected from a nonexposed site. The number of proteinuria cases were higher in the highly exposed subjects, although the nature (glomerular or tubular) of proteinuria remains unclear. However, it appears difficult to assess the degree of renal disturbance among the different exposure levels, such as the amount of excreted proteins, which have not clearly reflected the kidney lesion severity. The results also reveal that urine acidity increased progressively with increased levels of exposure, while a remarkable inverse relationship between urinary pH and urinary Hg in the highly exposed workers has been recorded. Furthermore, the significant differences in blood and urinary mercury concentrations of the three sites reflect the dose-response relationships.

[Absence of interaction between thiomersal and aluminum occlusion chambers]. / Absence d'interaction entre le thiomersal et les chambres d'occlusion en aluminium.

BACKGROUND: Positive patch tests to thiomersal are frequent, but of little relevance. Interaction between aluminium occlusive chambers and the mercury of thiomersal may elicit skin irritation and cause false positive results. METHODS: Between January 1998 and May 1999, the patients were simultaneously patch tested with aluminium and plastic chambers. Positive skin tests were compared. RESULTS: Seventeen of 213 subjects showed positive tests: 15 with the 2 materials, 1 only for the aluminium chamber, 1 for the plastic chamber. DISCUSSION: The results did not differ for the two materials. We concluded that positive reactions observed were not caused by interaction between aluminium and thiomersal.

Clinical efficacy and safety of a topical combination of retinaldehyde 0.1% with erythromycin 4% in acne vulgaris.

The objective of this randomized, controlled, multicentre study was to assess the efficacy and safety of a topically applied retinaldehyde 0.1% gel in combination with a topical erythromycin 4% lotion for the treatment of acne vulgaris. Treatment consisted of applying either retinaldehyde or its vehicle every morning and erythromycin every evening for 8 weeks. Efficacy parameters were sequential lesion counts for papules and pustules, and a 6-point semiquantitative scale for comedones and microcysts. Safety parameters were local tolerance and adverse events. Of 74 recruited patients, 73 were appraisable for efficacy and safety. In both treatment groups, papules and pustules were reduced significantly at the end of treatment (P < 0.001), and no statistical difference was observed between the groups. Comedones and microcysts were significantly improved with retinaldehyde combined with erythromycin (P = 0.005), but not with erythromycin alone. However, no statistical difference between the groups could be demonstrated (test power, 50%). Local tolerance of the combined treatment group was very satisfactory, as only a few patients experienced local irritation. In conclusion, retinaldehyde combined with erythromycin appears to be a valuable topical therapy in polymorphic acne.

[Diagnosis and evaluation of mitral endocarditis complicating obstructive cardiomyopathy using cardiac echo-Doppler]. / Diagnostic et bilan d'une endocardite mitrale compliquant une cardiomyopathie obstructive par écho-Doppler cardiaque.

The authors report a case of mitral endocarditis diagnosed by cardiac echo-Doppler and complicating an obstructive cardiomyopathy (OCM) in a 37-year-old woman. Despite the high degree of sub-aortic obstruction and the existence of an apparently severe mitral leak by Doppler analysis, the patient remained totally asymptomatic and the outcome was favourable with appropriate antibiotics. A review of the literature revealed 11 cases of endocarditis in a context of OCM, documented by echocardiography. Echo-Doppler enables precise evaluation of this grave and often poorly tolerated complication of OCM.

[Partial epilepsy in children in Algeria. Electroclinical and tomodensitometric study]. / Les épilepsies partielles de l'enfant en Algérie. Etude électro-clinique et tomodensitométrique.

The authors report the results of an electroclinical and tomographic study of 145 cases of partial epilepsy in children. Without advancing any views on etiology or symptomatologic classification, they analyse the various prognoses on the basis of case history, clinical aspects, symptomatology of seizures, EEG and tomographic signs. None of these factors in isolation appears to determine the prognosis of epilepsy. A significant percentage of apparently idiopathic epilepsies may develop adversely whereas half of the cases show a good prognosis.