[Individual and contextual factors associated with violent behaviours during psychiatric hospitalizations]. / Facteurs individuels et contextuels participant à l'apparition de comportements violents en cours d'hospitalisations psychiatriques.

BACKGROUND: The prevention of Physical Violent Behavior (VB) toward others during psychiatric hospitalization is a major concern of clinicians. These VBs can have a deleterious impact on the victims, inpatients or caregivers, as well as on the therapeutic milieu. Such violence can also have negative consequences for the assailant patients, such as repeatedly being hospitalized under restraint, stigmatization, and difficulties reintegrating into the community. OBJECTIVES: This study explored individual (age, gender, marital status, living status, diagnostic) and institutional (type of admission, length of stay, number of previous hospitalizations) risk factors, and how their interactions could increase the risk of VB during psychiatric hospitalizations. METHOD: The study was carried out over a period of four years in the psychiatry department of the Lausanne University Hospital, on the 15 wards (219 beds) specialized in acute psychiatric care for adults. All the patients admitted to one of these wards during this period (n=4518), aged between 18 and 65 years, were included in the study. The sample was divided in two groups: non-violent patients (NVPs) and violent patients (VPs). VBs, defined as physical aggressions against another person, were assessed by the Staff Observation Aggression Scale - Revised (SOAS - R). Only physical assaults, associated or not with other types of violence, involving hospitalized patients were analyzed. Personal and institutional factors were extracted from the hospital database. Chi2 independence tests were used to assess differences between groups. Logistic regression models were used to identify the links between each factor and the VB. Classification and regression trees were used to study the hierarchical effect of factors, and combinations of factors, on VBs. RESULTS: During the study period, 414 VBs were reported involving 199 patients (4.40 % of all patients). VPs were significantly younger, male, more likely to be unmarried and living in sheltered housing before hospitalization. In this group, the proportion of patients with diagnoses of schizophrenia, and/or schizophrenia with comorbid substance abuse and cognitive impairment, were higher compared to NVPs. VPs were more frequently admitted involuntarily, had a longer average length of stay and a greater number of previous hospitalizations. The logistic regression model performed on individual factors have shown a significant link between age (OR=0.99; CI: 0.97-1.00; P-value=0.024), living in sheltered housing before admission (OR=2.46; CI: 1.61-3.75; P-value<0.000), schizophrenic disorders (OR=2.18; CI: 1.35-3.57; P-value=0.001), schizophrenic disorders with substance abuse comorbidity (OR=2.00; CI: 1.16-3.37; P-value=0.016), cognitive impairment (OR=3.41; CI: 1,21-8.25; P-value=0.010), and VBs. The logistic regression model on institutional factors have shown a significant link between involuntary hospitalization (OR=4.38; CI: 3.20-6.08; P-value<0.000), length of previous stay (OR=1.01; CI: 1.00-1.01; P-value<0.000), number of previous hospitalizations (OR=1.06; CI: 1.00-1.12; P-value=0.031), and VBs. The logistic regression model on individual and institutional factors have shown a significant link between age (OR=0.99; CI: 0.97-1.00; P-value=0.008), living in sheltered housing before admission (OR=2.46: CI: 1.61-3.75; P-value=0.034), cognitive impairment (OR=3.41; CI: 1.21-8.25; P-value=0.074), involuntary hospitalization (OR=3.46; CI: 2.48-4.87; P-value<0.000), length of previous stay (OR=1.01; CI: 1.00-1.01; P-value<0.000), and VBs. The classification and regression trees have shown that the relationship between long length of stay and repeated hospitalizations mainly potentiate the risk of violence. CONCLUSION: The results of this study have shown the existence of a small group of vulnerable patients who accumulate constrained hospital stays during which violence occurs. Exploring the clinical profiles and institutional pathways of patients could help to better identify these patients and promote a more appropriate mode of support, such as intensive clinical case management. This model could facilitate the development of a clinical network and the links between the structures and partners caring for a patient. This would create a continuous support, avoiding or limiting the lack of continuity of care and care disruption.

'Silent' carriage of two familial Mediterranean fever gene mutations in large families with only a single identified patient.

The presence of two mutations in the familial Mediterranean fever gene, without overt familial Mediterranean fever (FMF), designated as phenotype III, predisposes to developing 'silent' AA amyloidosis, recognized as phenotype II, due to the absence of medical supervision and colchicine prophylaxis. We sought to determine the prevalence of phenotype III in large families with only one subject affected with FMF, in order to assess the population at risk for transformation to phenotype II. A total of seven large families were recruited for the study. Siblings were screened for MEFV mutations and underwent a clinical interview to assess for unrecognized FMF manifestations. Phenotype III, most commonly associated with a V726A/E148Q genotype, was detected in 10% of siblings of index cases from informative families, corresponding to a 10-fold increase in comparison to the expected rate in the general population (p < 0.01). Unnoticed 'FMF-like' manifestations were detected among two siblings in the five families in which the index case was heterozygous, but in none of the siblings of the homozygous index cases. The enrichment for phenotype III and detection of occult FMF in large families, in which only a single member is afflicted with FMF, mandates routine clinical evaluation and genetic screening of siblings.

Primary structure of the 175K Plasmodium falciparum erythrocyte binding antigen and identification of a peptide which elicits antibodies that inhibit malaria merozoite invasion.

The Plasmodium falciparum gene encoding erythrocyte binding antigen-175 (EBA-175), a putative receptor for red cell invasion (Camus, D., and T. J. Hadley. 1985. Science (Wash. DC). 230:553-556.), has been isolated and characterized. DNA sequencing demonstrated a single open reading frame encoding a translation product of 1,435 amino acid residues. Peptides corresponding to regions on the deduced amino acid sequence predicted to be B cell epitopes were assessed for immunogenicity. Immunization of mice and rabbits with EBA-peptide 4, a synthetic peptide encompassing amino acid residues 1,062-1,103, produced antibodies that recognized P. falciparum merozoites in an indirect fluorescent antibody assay. When compared to sera from rabbits immunized with the same adjuvant and carrier protein, sera from rabbits immunized with EBA-peptide 4 inhibited merozoite invasion of erythrocytes in vitro by 80% at a 1:5 dilution. Furthermore, these sera inhibited the binding of purified, authentic EBA-175 to erythrocytes, suggesting that their activity in inhibiting merozoite invasion of erythrocytes is mediated by blocking the binding of EBA-175 to erythrocytes. Since the nucleotide sequence of EBA-peptide 4 is conserved among seven strains of P. falciparum from throughout the world (Sim, B. K. L. 1990. Mol. Biochem. Parasitol. 41:293-296.), these data identify a region of the protein that should be a focus of vaccine development efforts.

A Plasmodium falciparum antigen that binds to host erythrocytes and merozoites.

Antigens that bind to erythrocytes were identified in the supernatant fluids of a cultured human malaria parasite (Plasmodium falciparum). A 175-kilodalton (175K) antigen bound only to erythrocytes susceptible to invasion. The 175K antigen from the Camp or the FCR-3 strain also bound to merozoites. However, the antigen did not bind to merozoites when merozoites and supernatant antigens were from different strains unless proteinase inhibitors were present. Moreover, erythrocytes coated with supernatant antigens from the Camp or FCR-3 strain were invaded normally by merozoites of the homologous strain but were partially resistant to invasion by merozoites of the heterologous strain. The 175K antigen may be a receptor acting as a "bridge" between erythrocytes and merozoites.

Diagnosis of invasive aspergillosis using bronchoalveolar lavage in haematology patients: influence of bronchoalveolar lavage human DNA content on real-time PCR performance.

In order to improve invasive pulmonary aspergillosis (IPA) diagnosis, a real-time polymerase chain reaction (PCR) assay detecting Aspergillus spp. was developed. Its detection limit reached 2-20 conidia. The retrospective evaluation on 64 bronchoalveolar lavage (BAL) fluids from 57 patients at risk for IPA, including 20 probable and five proven IPA patients, revealed a 88% or 38% sensitivity in direct examination (DE)/culture-positive or culture-negative BAL, respectively, whereas galactomannan (GM) sensitivity reached 88% or 58%, respectively. Influence on the Aspergillus-PCR yield of BAL fluid volume, cellular count and DNA content (evaluated by human beta-globin quantification) was assessed. Significantly higher beta-globin levels were detected in Aspergillus PCR-positive (median 5,112 pg/microl) than negative (median 1,332 pg/microl) BAL fluids, suggesting that the beta-globin level could reflect BAL yields and DNA extraction. Using beta-globin for the interpretation of fungal PCR could improve the negative predictive value of this test.

Total shoulder prosthesis with humeral resurfacing: Impact on lateral offset and short-term clinical consequences.

BACKGROUND: Reports of early glenoid wear after humeral resurfacing hemiarthroplasty have prompted the use, in combination with this procedure, of newly developed glenoid implants. This combination can increase global humeral offset. The objectives of this study were to assess changes in overall lateral offset and their potential short-term clinical consequences after combined humeral resurfacing and glenoid replacement. HYPOTHESIS: Combined humeral resurfacing and glenoid replacement induces a large increase in overall lateral offset, resulting in short-term clinical consequences. MATERIAL AND METHODS: A single-centre prospective study was started in November 2011. Consecutive patients scheduled for total shoulder arthroplasty with humeral resurfacing were included. The primary outcome measure was the change in lateral offset between radiographs obtained pre-operatively and 3 months post-operatively. The functional outcome assessed using the Constant score was compared between the groups with a lateral offset change <10mm vs. ≥10mm. RESULTS: From November 2011 to November 2014, 35 total shoulder arthroplasties with humeral resurfacing were performed in 32 patients with a mean age of 72.1 years (range, 55-86 years). Mean follow-up was 20±6 months (range, 12-31 months). Overall lateral offset was significantly greater post-operatively than pre-operatively (14±6mm vs. 5±7mm, p<0.0001), the mean difference being 8mm (range, 2-20mm). Post-operative range of motion was better in the group with an overall lateral offset ≥10mm (p=0.0016). DISCUSSION: Combined humeral resurfacing and glenoid replacement markedly increases overall lateral offset. This increase is not associated with adverse effects on short-term function and may improve post-operative motion range. However, greater lateral offset elevates the loads on the glenoid implant, which may increase the risk of glenoid implant loosening and rotator cuff tearing. Close radiological monitoring is therefore imperative. LEVEL OF EVIDENCE: IV, prospective cohort study.

[Relevance of the toxoplasma IgG avidity test in the serological surveillance of pregnant women]. / Intérêt de l'indice d'avidité des IgG pour le diagnostic d'exclusion d'une toxoplasmose récente : comparaison de la trousse Toxo IgG Avidité SFRI à la trousse Toxo IgG Avidity Vidas.

In addition to the serological systematic screening tests, kits to measure the avidity of toxoplasma IgG antibodies are currently available. Since high-avidity IgG toxoplasma antibodies have been shown to exclude recent infection, IgG avidity determination is especially useful in ruling out acute infection having occurred in the 3-4 prior months of pregnancy. We therefore compared the efficacy of two toxoplasma IgG avidity ELISA kits: SFRI (SFRI Laboratoire) and VIDAS Toxo-IgG avidity kit (bioMérieux). The agreement of the results from the 2 commercial assays were analysed using 55 serum samples, in terms of global mother-child Toxoplasma results and outcome, specially with light of the results of Toxoplasma antenatal, postnatal assays and of clinical follow up of children.

Beta-1,2-linked oligomannosides inhibit Candida albicans binding to murine macrophage.

Interaction of Candida albicans with cells of the macrophage lineage was examined by using heat-killed (HK) and live yeast cells. Laminarin, an analogue of the cell wall beta-glucans, strongly inhibited HK yeasts adherence to J774 cell line but had no effect on live yeast binding. Phosphopeptidomannan (PPM) from Saccharomyces cerevisiae had a limited effect on the binding of both HK and live yeasts but significant inhibition was achieved by the use of C. albicans PPM. The role of beta-1,2-oligomannosides was examined with regard to their exclusive presence within C. albicans PPM. PPM acid labile beta-1,2-oligomannosides or a synthetic beta-1,2-mannotetraose, inhibited yeasts binding in a manner comparable to the original PPM. These latter results were confirmed by using mouse peritoneal macrophages, thus suggesting a general role for beta-1,2-oligomannosides in the adherence of the yeast to the macrophage membrane.

[Candida albicans meningo-encephalo-myelo-radiculitis at an addict]. / Méningo-encéphalo-myélo-radiculite à Candida albicans chez un toxicomane.

Beside immunodepression induced by the human immunodeficiency virus, fungal infections of the central nervous system are extremely rare in heroin-addict patients. We report here a case of meningo-encephalitis with myelo-radicular lesions in a 25-year-old intravenous heroin addict but non-HIV patient, who was admitted for an acute confusion associated with gait disorders. The diagnosis of Candida albicans meningo-encephalo-myelo-radiculitis was established by magnetic resonance imagery and mycological and serological examinations of cerebrospinal fluid. The infection was cured with amphotericin B lipid complex and 5-fluorocytosine. Early diagnosis and antifungal therapy for 6 months resulted in a favorable outcome. The detection of circulating Candida mannan in cerebrospinal fluid with a more sensitive technique combined to MRI were particularly decisive to confirm Candida infection diagnosis, allowing an appropriate antifungal therapy.

[Real-time quantitative PCR for toxoplasmosis diagnosis]. / Apport de la PCR quantitative en temps réel dans le diagnostic de la toxoplasmose congénitale.

Congenital toxoplasmosis results from foetus contamination by Toxoplasma gondii during pregnancy. It is a frequent and severe condition calling for close monitoring of mothers at risk. During the last decades, numerous advances have been made specially in the antenatal diagnosis. The congenital toxoplasmosis diagnosis relies currently on PCR test of amniotic fluid, with a sensitivity of 80%. More recently, real-time quantitative PCR has been developed to improve toxoplasmosis diagnosis. We therefore compared the diagnosis value of quantitative real-time PCR with our conventional PCR-hybridization for the diagnosis of congenital toxoplasmosis.

Increase in glutathione peroxidase activity in malaria parasite after selenium supplementation.

Glutathione peroxidase (GPx), a key enzyme involved in the detoxification of many peroxides, has been investigated in two malaria parasite species: P. yoelii in vivo (murine malaria) and P. falciparum in vitro (human malaria). We demonstrate the presence of an endogenous GPx activity in these two Plasmodia species. Enzymatic assays and the use of specific substrates and inhibitors allowed us to determine that the activity is selenium dependent. As this activity was shown to be lower in P. falciparum than in P. yoelii, and selenium levels were found to be low in culture medium and culture red blood cells, we hypothesized that a severe selenium deficiency could be responsible for this difference. After selenium supplementation, with either sodium selenite or selenocystine, we observed an increase in growth of P. falciparum only in with sodium selenite, whereas higher GPx activities were noted in parasites grown in media supplemented with both. An increase in GPx activities was also observed in parasites that had undergone an experimental oxidative stress with TBOOH. As the erythrocyte is unable to synthesize new proteins, these results provide further evidence for the existence of an endogenous parasitic selenium-dependent glutathione peroxidase.

Characterization of microneme proteins of Toxoplasma gondii.

Three microneme proteins of Toxoplasma gondii have been characterized using 3 monoclonal antibodies and a recombinant protein specific antiserum. In all cases, apical labeling of tachyzoites and bradyzoites was observed by indirect immunofluorescence assay. Immunogold localization on ultrathin sections of bradyzoites or tachyzoites showed a specific labeling of micronemes. The following proteins were characterized using 2-dimensional gel electrophoresis and Western immunoblotting: Mic 1 (60 kDa, Pi 6.5), Mic 2 (120 kDa, Pi 5) and Mic 3 (90 kDa, Pi 6.75). The 90-kDa protein (Mic 3) is a heterodimer of two 38-kDa polypeptides (Pi 6.7 and 6.75 respectively) linked by disulfide bridges. Metabolic labeling and immunoprecipitation assays showed that at least one of the 38-kDa polypeptides was processed from a 40-kDa precursor. No processing was observed during the biosynthesis of the 120- and 60-kDa polypeptides.

Characterization of gp195 processed products purified from Plasmodium falciparum culture supernates.

Schizonts of the malaria parasite Plasmodium falciparum synthesize a 195 kDa surface glycoprotein (gp195) that is processed into several smaller products including one of 83 kDa, which, in the case of the Camp strain, is sequentially processed into 73 and 67 kDa products. gp195 and its processing intermediates larger than 83 kDa were not precipitated from culture supernates, but the 83 and 73 kDa products were precipitated by three monoclonal antibodies (McAbs). The 83 and 73 kDa products were affinity purified from culture supernates by adsorbing to McAb 7B2 coupled to Affigel 10 and eluting either with 0.2 N acetic acid, pH 2.8, or with 3 M potassium isothiocyanate (KSCN). The epitope recognized by McAb 7B2 was denatured by acid elution but could be regenerated by treating with 8 M urea followed by dialysis. The implications of renaturing antigens to regenerate epitopes should be considered in studies on the purification, function and immunogenicity of malaria antigens.

Intramolecular mapping of Plasmodium falciparum P126 proteolytic fragments by N-terminal amino acid sequencing.

Protein P126 (also called P140, P113, SERA, SERP1) is a major parasitophorous vacuole antigen of Plasmodium falciparum. This protein is processed upon merozoite release into 2 fragments of 73 kDa (P73) and 50 kDa (P50), which are found in the culture medium. P73 is composed of 2 polypeptides of 47 and 18 kDa linked by disulfide bridges. In the presence of leupeptin, an inhibitor of serine and cysteine proteases which inhibits merozoite release, a 56-kDa intermediate product (P56) is recovered in the culture medium instead of P50. In order to map these proteolytic fragments on the 126-kDa precursor, we purified them from Plasmodium falciparum culture medium by immunoadsorption, SDS-electrophoresis and Western blotting on PVDF membrane and determined the N termini of P126, P73 (P47 and P18), P50 and P56. Comparison of these sequences with the amino acid sequence deduced from the P126 gene allowed the mapping of the different fragments on the precursor. P47 was at the N-terminal and P18 at the C-terminal end of P126. P56 and P50 had the same N-termini and were located in the middle of P126. This latter result indicates that the proteolysis of P56-P50 occurs at the C-terminus of P56. The peptide bonds cleaved by leupeptin-insensitive activities are Glu-Thr and Gln-Asp; C-terminal sequencing of P50 will be needed to identify the leupeptin-sensitive cleavage site.

Molecular characterization of the glutathione peroxidase gene of the human malaria parasite Plasmodium falciparum.

In this paper we report the isolation and the characterization of a gene encoding the antioxidant enzyme glutathione peroxidase from the human malaria parasite Plasmodium falciparum. This gene contains two introns of 208 and 168 bp and is present in a single copy on chromosome 13. The open reading frame encodes a protein with a predicted length of 205 amino acids, which possesses a potential cleavage site between residues 21 and 22 after a hydrophobic region with the characteristics of a signal sequence. Therefore, the mature protein is predicted to be 184 residues long with a molecular mass of 21404 Da. In comparison with other known glutathione peroxidases many amino acid residues implicated in catalysis are conserved in the malarial enzyme. Phylogenetic analysis indicates that the deduced protein sequence is more closely related to plant glutathione peroxidase and phospholipid hydroperoxide glutathione peroxidase. A 1.5-kb transcript was identified in asynchronous erythrocytic stages.

Isolation and characterization of a subtractive library enriched for developmentally regulated transcripts expressed during encystation of Toxoplasma gondii.

To survive within infected hosts, Toxoplasma gondii undergoes profound metabolic and morphological changes by differentiating into a cyst characterized by its resistance to the immune system and chemotherapy. The stimulus that triggers Toxoplasma encystation and the molecular mechanisms regulating the bradyzoite phenotype are still unknown. Here, we developed a differentiation method in conjunction with a selective and subtracted cDNA strategy devised to identify developmentally regulated transcripts. We isolated and analyzed 65 cDNA clones. In addition to bradyzoite specific cDNAs previously reported, we demonstrate that twelve genes are exclusively or preferentially transcribed in the encysted bradyzoite forms of T. gondii using semi-quantitative RT-PCR. Among cDNAs identified, are those encoding predicted homologues of chaperones (mitochondrial heat shock protein 60, T-complex protein 1), DNA-damage repair protein, phosphatidylinositol synthase, glucose-6-phosphate isomerase and enolase. The identification of these genes opens the way for further study of molecular mechanisms controlling gene expression during T. gondii encystation.

Molecular cloning of the Toxoplasma gondii sag4 gene encoding an 18 kDa bradyzoite specific surface protein.

An 18 kDa bradyzoite specific surface protein of Toxoplasma gondii (T. gondii) has been purified by affinity chromatography with a specific monoclonal antibody using parasites grown in vitro under conditions inducing the biosynthesis of bradyzoite specific proteins. N-terminal and internal amino acid sequences obtained by microsequencing enabled us to design degenerate oligonucleotides. A fragment of 187 bp was amplified by polymerase chain reaction (PCR). It was used as a probe to clone a 4 kb-Bam HI fragment encompassing the gene encoding the 18 kDa protein. Nucleotide sequence analysis revealed a single open reading frame of 516 nucleotides encoding a 172 amino acid protein. The deduced amino acid sequence matched perfectly the peptides microsequenced from the native protein. The N-terminal hydrophobic region was found to possess the characteristics of a signal peptide of 27 amino acids. The hydrophobic C-terminal part could represent a signal for a glycan-phosphoinositide anchor. The full-length cDNA was also isolated and both the 5' and 3' untranslated regions were determined. Reverse transcriptase-PCR (RT-PCR) using p18-specific primers showed a stage-specific expression of this gene. Comparison of the nucleic acid sequence and the predicted amino acid sequence with databases did not reveal significant homology with known genes or proteins. This gene is proposed to be named sag4, according to the existing T. gondii nomenclature.

Characterization of iron-dependent endogenous superoxide dismutase of Plasmodium falciparum.

Two main superoxide dismutase activities at isoelectric points (pI) 6.2 and 6.8 and two minor at pI 5.6 and 6.4 were found in crude extracts of Plasmodium falciparum. These activities were cyanide-resistant and hydrogen peroxide-sensitive and represented 20-30% of the total SOD activity found in the crude extract. A fragment of 424 bp, amplified from genomic DNA from P. falciparum, was cloned and sequenced. The deduced amino acid sequence identified this fragment as a coding region of an SOD gene. A cDNA corresponding to SOD was then isolated from a P. falciparum cDNA library and sequenced. The deduced amino acid sequence of SOD (197 aa) was compared with 32 known Feor Mn-SODs by the 'DARWIN' system. This analysis showed that the parasitic enzyme was related to typical Fe-SODs. The SOD subunit was purified and the N-terminal sequence, determined up to 29 residues, corresponded to that of cDNA isolated. The iron-dependent SOD activity found in Plasmodium falciparum represents the first level of the antioxidant defence system of the parasite. It is also the first SOD characterized in the parasitic Apicomplexa phylum whose sequence can be compared to equivalent iron-dependent enzymes known in other protozoa and bacteria.

Molecular cloning, expression analysis and iron metal cofactor characterisation of a superoxide dismutase from Toxoplasma gondii.

A genomic region of 12 kb encompassing the gene encoding the superoxide dismutase (SOD) of Toxoplasma gondii has been cloned. The gene contains four exons of 121, 42, 381 and 59 bp which are separated by three introns of 321, 202, and 577 bp, respectively. The open reading frame can be translated into a protein of 201 amino acids with a molecular mass of 22.6 kDa. Alignment indicated that it is a FeSOD, a type only found in bacteria, protozoa and chloroplast of higher plants. Recombinant SOD was expressed in a Escherichia coli double mutant lacking both MnFeSOD and FeSODs. The presence of iron as metal cofactor was confirmed by measurements of iron by absorption mass spectrometry and electron paramagnetic resonance studies. Semi-quantitative reverse transcribed polymerase chain reaction experiments showed a similar amount of SOD transcripts in two developmental stages of T. gondii. Antibodies raised against the purified recombinant protein detected SOD protein in both bradyzoite and tachyzoite forms suggesting this SOD might be essential for the intracellular growth of both developmental stages. Southern blot analysis indicated that SOD occured as a single copy gene in T. gondii genome.

The MIC1 microneme protein of Toxoplasma gondii contains a duplicated receptor-like domain and binds to host cell surface.

The cDNA encoding the Toxoplasma gondii microneme protein MIC1 and the corresponding gene have been cloned and sequenced. The MIC1 gene contains three introns. The cDNA encodes a 456 amino acid (aa) sequence, with a typical signal sequence and no other trans-membrane domain. The protein contains a tandemly duplicated domain with conservation of cysteines and presents distant homology with the Plasmodium sp. microneme protein TRAP-SSP2. The MIC1 protein from tachyzoite lysates and a PMAL recombinant expressing the N-terminal duplicated domain of the protein bound to the surface of putative host cells, suggesting a possible involvement of MIC1 in host cell binding/recognition.