Antifungal coating by biofunctionalized polyelectrolyte multilayered films

The surface of medical devices is a common site of bacterial and fungal adhesion, first step to the constitution of a resistant biofilm leading frequently to chronic infections. In order to prevent such complications, several physical and chemical modifications of the device surface have been proposed. Here, we experiment a new type of topical antifungal coating using the layer-by-layer technique. The nanometric multilayer film obtained by this technique is functionalized by the insertion of a chromogranin A-derived antifungal peptide (CGA 47-66, chromofungin). We show that the embedded peptide keeps its antifungal activity by interacting with the fungal membrane and penetrating into the cell. In vitro studies demonstrate that such an antifungal coating is able to inhibit the growth of yeast Candida albicans by 65% and completely stop the proliferation of filamentous fungus Neurospora crassa. The cytotoxicity of such a coating was also assessed by growing human gingival fibroblasts at its surface. Finally, the antifungal coating of poly(methylmethacrylate), a widely used material for biomedical devices, is successfully tested in an in vivo oral candidiasis rat model. Taken together, these results assessed the functionalized multilayer films containing a new potent antifungal non-toxic peptide, as a novel and promising technique for local antifungal protection.     

X-linked dominant chondrodysplasia with platyspondyly, distinctive brachydactyly, hydrocephaly, and microphthalmia

We describe a family with an X-linked dominant chondrodysplasia. Four males and six females were affected through four generations. Identification of skeletal abnormalities and hydrocephaly during the pregnancy of three male fetuses led to termination of the pregnancies. A fourth affected male died at 6 days of life. The four patients had chondrodysplasia, hydrocephaly, and facial features with microphthalmia. Radiographs showed severe platyspondyly and various bone abnormalities including a distinctive metaphyseal cupping of the metacarpals, metatarsals, and phalanges. The affected females were less affected and showed small stature, sometimes associated with body asymmetry and mild mental retardation. This condition appears to be a previously unrecognized X-linked dominant chondrodysplasia.     

Emergence in Cx knockout mice of a diverse cytotoxic T lymphocyte repertoire that recognizes a single peptide from the immunoglobulin constant x light chain region

Allotype- or idiotype-specific CD4⁺ T cells have been reported to recognize immunoglobulin (Ig) peptides presented by class II molecules. In contrast, few data are available concerning the generation of Ig peptide-specific CD8⁺ T cells. We have therefore investigated whether T-depleted spleen cells from Ig x light chain-expressing 129/Sv mice (129x^+/+) could induce, in Cx knockout mice (129 x^?/?), the generation of Ig constant x light chain region (Cx)-specific cytotoxic T lymphocytes (CTL). The determination of TCRβ chain expressed by nine CTL clones, together with the use of a library of overlapping peptides spanning the whole Cx sequence, show that the B cells from x^+/+ mice are able to elicit in Cx knockout mice, the emergence of a diverse CTL repertoire that recognizes one single Cx peptide presented by the H-2K^b class I molecule. In addition, these data support the notion that B cells are able to process and present on their class I molecules, peptides generated from their own x light chains.     

Disruption of the gene homologous to mammalian Nramp1 in Mycobacterium tuberculosis does not affect virulence in mice

Natural-resistance-associated macrophage protein 1 (Nramp1) is a divalent cation transporter belonging to a family of transporter proteins highly conserved in eukaryotes and prokaryotes. Mammalian and bacterial transporters may compete for essential metal ions during mycobacterial infections. The mycobacterial Nramp homolog may therefore be involved in Mycobacterium tuberculosis virulence. Here, we investigated this possibility by inactivating the M. tuberculosis Nramp1 gene (Mramp) by allelic exchange mutagenesis. Disruption of Mramp did not affect the extracellular growth of bacteria under standard conditions. However, the Mramp mutation was associated with growth impairment under conditions of limited iron availability. The Mramp mutant displayed no impairment of growth or survival in macrophages derived from mouse bone marrow or in Nramp1(+/+) and Nramp1(-/-) congenic murine macrophage cell lines. Following intravenous challenge in BALB/c mice, counts of parental and Mramp mutant strains were similar in the lungs and spleens of the animals at all time points studied. These results indicate that Mramp does not contribute to the virulence of M. tuberculosis in mice.     

DFNB40, a recessive form of sensorineural hearing loss, maps to chromosome 22q11.21-12.1

We report on a novel localization for a recessive form of deafness (DFNB), by linkage analysis in an Iranian consanguineous family. Affected individuals suffer from prelingual profound sensorineural hearing loss. Genome-wide analysis led to the characterization of a new locus, DFNB40, which maps to an approximately 9 Mb interval between markers D22S427 and D22S1144 at chromosome 22q11.21-12.1. Maximum lod score of 3.09 was obtained with D22S1174. Since the Bronx waltzer (bv) mouse mutant, characterized by waltzing behavior, deafness, and degeneration of cochlear inner hair cells, has been mapped to the syntenic region on murine chromosome 5, we suggest that DFNB40 and bv may result from orthologous gene defects.     

Short stature in a girl with a terminal Xp deletion distal to DXYS15: localisation of a growth gene(s) in the pseudoautosomal region.

This report describes a Japanese girl with short stature and a rearranged X chromosome. Her height remained below the 3rd centile growth curve for Japanese girls, and her predicted adult height (148.5 cm) was below her target height (163 cm) and target range (155 to 171 cm). Cytogenetic studies showed that the rearranged X chromosome was formed by a breakage at q26 and a transfer of the Xq fragment onto the tip of Xp. The abnormal X was always late replicating. No mosaicism was detected. Molecular analysis showed an Xp terminal deletion distal to DXYS15. Biochemical and radiological studies for short stature disclosed no abnormality. On the basis of height analysis of previous reports and a genotype-phenotype correlation of this patient, we propose that a growth gene(s) is present in the distal part of the pseudoautosomal region.     

Pathology of inverted Takotsubo cardiomyopathy

Myocardial dysfunction without coronary involvement may occur in acute cerebral diseases. The inverted Takotsubo pattern has been recently recognized as a novel heart neurologic stress-related syndrome. We report on the case of a 40-year-old woman presenting with massive subarachnoid hemorrhage and brain death. Echocardiography revealed an extensive left ventricular circumferential akinesis except at the apex. Histologic analysis of the heart confirmed the absence of myocardial infarction and revealed only sparse foci of myocyte necrosis with contraction bands in the akinetic areas.     

Analysis of tetanus toxin peptide/DR recognition by human T cell receptors reconstituted into a murine T cell hybridoma

We have previously reported that human T cell receptors (TcR) selected in the class II-restricted (HLA-DRB1*1302) response to a tetanus toxin peptide (tt830-843) frequently used the Vβ2 germ-line segment which paired with several Vα segments and that the putative CDR3 of both α and β chains showed remarkable heterogeneity. To analyze the structural basis for recognition of the tt830-843/DR complex, five of these TcR were reconstituted into a murine T cell hybridoma, 58 α^?β^?, by expressing the human α and β variable regions joined to the mouse α and β constant regions, respectively. The chimeric TcR, expressing the same Vβ germ-line segment (Vβ2), two expressing Vα21.1, twoVα17.1 and one Vα8.1 were shown to have the expected antigen specificity and DR restriction. Two lines of evidence suggested that the putative CDR3, although not conserved in these TcR, played a key role in recognition. First, two TcR with identical V germ-line segments but distinct CDR3 showed large differences in their capacity to react with the ligand. Second, interchanging the α and β chains from tt830-843/DR1302-specific TcR which differed in their CDR3 sequences invariably led to loss of recognition. We also asked whether germ-line Vα17.1 could functionally replace Vα21.1, as they appear to be related in their primary sequence. However, as in the case of CDR3 exchanges, Vα replacement abrogated TcR reactivity. Taken together, these data underline the fine interdependence of the structural components of the TcR binding site in defining a given specificity. Four of the TcR studied displaying promiscuous recognition were also tested against different DR alleles and site-directed mutants. The results of these experiments suggested that, in spite of their structural heterogeneity, anti-tt830-843 TcR may have a similar orientation with respect to the peptide/DR complex. The reconstitution system described herein should represent a valuable tool for detailed studies of human TcR specificity.     

Use of an automated multiple-locus, variable-number tandem repeat-based method for rapid and high-throughput genotyping of Staphylococcus aureus isolates

Fast and reliable genotyping methods that allow real-time epidemiological surveillance would be instrumental to monitoring of the spread of methicillin-resistant Staphylococcus aureus. We describe an automated variable-number tandem repeat-based method for the rapid genotyping of Staphylococcus aureus. Multiplex PCR amplifications with eight primer pairs that target gene regions with variable numbers of tandem repeats were resolved by microcapillary electrophoresis and automatically assessed by cluster analysis. This genotyping technique was evaluated for its discriminatory power and reproducibility with clinical isolates of various origins, including a panel of control strains previously characterized by several typing methods and collections from either long-term carriers or defined nosocomial outbreaks. All steps of this new procedure were developed to ensure a rapid turnaround time and moderate cost. The results obtained suggest that this rapid approach is a valuable tool for the genotyping of S. aureus isolates in real time.     

Amantadine therapy in renal transplant patients with hepatitis C virus infection.

BACKGROUND: To date, there is no safe and efficient treatment of hepatitis C virus (HCV) infection after renal transplantation. Recently, there were encouraging reports after using amantadine in HCV-positive immunocompetent patients. OBJECTIVES: In an open pilot study, we evaluated the efficacy and the safety of amantadine monotherapy in 8 HCV positive renal-transplant patients with chronic active hepatitis and increased alanine aminotransferase (ALT) levels. RESULTS: After 6 months of amantadine therapy (200 mg per day), there were no decrease in HCV viremia (5.87 +/- 0.37 log copies/ml at M6 versus 5.71 +/- 0.5 log copies/ml at baseline; P > 0.05). However, we found a significant decrease in ALT activity (71 +/- 17 IU/l at M6 versus 100 +/- 9 IU/l at baseline; P = 0.04), whereas the decrease in aspartate aminotransferase activity did not reach statistical significance. There were no significant changes in liver histology. The clinical and biological tolerance was very good. Finally, there were a significant decrease in cyclosporine A whole blood trough levels during therapy. CONCLUSIONS: Our study is the first one to demonstrate that amantadine monotherapy lack of efficacy in HCV renal-transplant patients. It is able to improve liver enzymes but it has no impact neither upon HCV viremia nor upon liver histology.