Chemical VOC sensing mechanism of sol-gel ZnO pellets and linear discriminant analysis for instantaneous selectivity.

This work reports on the integration of ZnO pellets for use as a virtual sensor array (VSA) of volatile organic compounds (VOCs). ZnO pellets consist of nano-powder prepared using a sol-gel technique. The microstructure of the obtained samples was characterized by XRD and TEM methods. The response to VOCs at different concentrations was measured over a range of operating temperatures (250-450 °C) using DC electrical characterization. The ZnO based sensor showed a good response towards ethanol, methanol, isopropanol, acetone and toluene vapors. We note that the highest sensitivity (0.26 ppm-1) is obtained with ethanol while the lowest one (0.041 ppm-1) corresponds to methanol. Consequently, the limit of detection (LOD) estimated analytically reached 0.3 ppm for ethanol and 2.0 ppm for methanol at an operating temperature of 450 °C. The sensing mechanism of the ZnO semiconductor was developed on the basis of the reaction between the reducing VOCs with the chemisorbed oxygen. We verify through the Barsan model that mainly O- ions in the layer react with VOC vapor. Furthermore, dynamic response was investigated to construct mathematical features with distinctly different values for each vapor. Basic linear discrimination analysis (LDA) shows a good job of separating two groups by combining features. In the same way we have shown an original reason embodying the distinction between more than two volatile compounds. With relevant features and VSA formalism, the sensor is clearly selective towards individual VOCs.

Efficacy and safety of methylphenidate on attention deficit hyperactivity disorder in children with Down syndrome.

BACKGROUND: Attention deficit hyperactivity disorder (ADHD) is a common co-morbidity that affects up to 44% of children with Down syndrome (DS). There is a need for reliable, good quality research on the use of methylphenidate within this population. The objective of this study is to report our experience regarding the management of ADHD in these children using methylphenidate. METHODS: This study is a retrospective observation of 21 children with DS, followed at Jérôme Lejeune Institute between 2000 and 2018. The diagnosis of ADHD was made using the Diagnostic and Statistical Manual of Mental Disorders criteria. Efficacy was measured as response or non-response on two main symptoms: attention/concentration and hyperactivity/impulsivity. Safety was evaluated by the presence or absence of side effects. RESULTS: Sixteen out of the 21 children (76%) showed improvement with methylphenidate. The average age of treatment onset in responding children was 8 years and 10 months versus 6 years and 3 months in non-responders (P = 0.05). Average dose/weight was significantly different in responders and non-responders (0.82 vs. 0.54 mg/kg/day, respectively; P = 0.03). Twelve children out of 21 (57%) experienced side effects; only three experienced side effects severe enough to require treatment interruption. Most common side effects were loss of appetite and difficulties in falling asleep. CONCLUSION: Methylphenidate was effective and safe in treating ADHD in 76% of cases in children with DS, with few serious side effects to report. Early diagnosis of ADHD is important to improve the quality of life, learning, inclusion and socialisation of children with DS.

[Assessment of mental states at risk of psychotic transition in a sample of young male prisoners in Tunisia]. / Évaluation des états mentaux à risque de transition psychotique dans un échantillon de jeunes détenus de sexe masculin en Tunisie.

BACKGROUND: Prevalence of psychotic disorders in a prison population is higher than in the general population. Recent research has shown that early intervention is feasible in prison settings, and that approximately 5% of screened prisoners have met ultra-high-risk (UHR) for psychosis criteria. We aimed to identify the prevalence of the UHR states for developing psychosis in a group of newly incarcerated men in the Jendouba Civil Prison and to analyze the association between UHR states and socio-demographic data and substance use. METHOD: We carried-out a cross-sectional study among 120 prisoners. Every prisoner was interviewed using the Comprehensive Assessment of At-Risk Mental States (CAARMS). The Social and Occupational Functioning Assessment Scale (SOFAS) was used to assess the participant's level of functioning. RESULTS: We found a prevalence of subjects meeting the UHR criteria of 21.3%. UHR subjects had significantly more psychiatric family history (P=0.035), personal history of suicide attempt(s) (0.035) and self-injury (P=0.013) compared to non-UHR subjects. Clinical self-evaluation found significantly more depression and anxiety in the UHR group (P=0.020 and P=0.035, respectively). In addition, social and occupational functioning was significantly more impaired in the UHR group (P=0.007). UHR subjects used significantly more cannabis in lifetime (P=0.015) as well as in the past year (P=0.022) and had a significantly higher frequency of cannabis use (P=0.01) compared to non-UHRs. CONCLUSION: Prison mental health teams face the challenge of identifying prisoners who need mental health services and providing early care to this vulnerable group; this challenge may offer a unique opportunity for intervention among a population that might not otherwise have had access to it.

Thickness effect on VOC sensing properties of sprayed In2S3 films.

This work reports the thickness effect on the sensing performances of In2S3 material for some Volatile Organic Compounds (VOCs). In2S3 films were deposited on glass substrates by the spray pyrolysis technique. Different samples were prepared via changing the spray time in the range of 10-90 min. The film thickness varies from 0.8 µm to 6.1 µm. The X-ray diffraction results demonstrate that the In2S3 films are polycrystalline in nature and exhibit a cubic structure. Additionally, Scanning Electron Microscopy (SEM) and 3D profilometry examinations show that the surface roughness increases with the rising spray time. On the other hand, the oxygen adsorption versus working temperature was investigated. Sensing measurements with ethanol, methanol and acetone gases were carried out by a dynamic control of the current passing through the sensitive layers. The best sensitivity was obtained for the film matching a 70 min deposit time. An understanding of the detection mechanism based on the oxidation reaction between reduced vapors and chemisorbed oxygen was confirmed. The selectivity of the sensor was analyzed for several volatile organic compounds (VOCs).

[Mesenteric lymph node cavitation in celiac disease: Report of four cases and literature review]. / Le syndrome de cavitation ganglionnaire mésentérique, complication rare de la maladie cœliaque de l'adulte : à propos de quatre cas et revue de la littérature.

INTRODUCTION: Mesenteric lymph node cavitation is an exceptional complication of celiac disease. We report four original observations of this syndrome, completed by a literature review. DISCUSSION: The analysis of 38 cases showed that this complication occurred exclusively in adults, with a mean age at diagnosis of 54 years. It revealed the celiac disease in the majority of cases. Hyposplenism was almost systematically associated. The risk of lymphoma appeared higher, especially enteropathy-associated T-cell lymphoma. The prognosis was poor with nearly 50% mortality and seemed related to the clinical response to the gluten-free diet. CONCLUSION: The severity of this complication deserves to be known and should lead to its research in celiac patients, especially in cases diagnosed in adulthood or in case of refractory disease.

[Analysis of the diagnostic efficiency of the Schirmer test versus the lacrimal meniscus biometric technique in impaired tear production].

The paper analyzes the diagnostic capacities of two studies (the routine Schirmer test and lacrimal meniscus biometry). It indicates the basic limitations of the Schirmer test and describes a procedure for lacrimal meniscus biometry. Based on the results of studying the lacrimal meniscus in healthy individuals from a control group, the authors revealed a relationship of the height of the lacrimal meniscus to the area and horizontal size of the palpebral fissure. Comparison of the results of studies of basal lacrimal secretion in the presence of dry keratoconjunctivitis and dry eye syndrome in the study patients with hypolacrimation defined the latter as mild, moderate, and severe. There was discordance between the values in 33.85% of cases. The Schirmer test has not shown to be the method of choice in examining basal lacrimal production; erroneous results may be obtained in a third of patients. Lacrimal meniscus biometry makes it possible to identify the degree of significant hypolacrimation more exactly and to minimize the indices of preserved basal secretion.

Mycobacterium recombinant vaccines.

Intracellular diseases are difficult to treat and constitute a major problem for modern medicine. In this type of diseases, a TH-1 immune response favors protection, while a TH-2 response is detrimental to the host. Current vaccines are using antigens to initiate an immune response regardless of its nature and its mechanism. New vaccines are designed to combine selected antigens with potent adjuvants to stimulate the appropriate pathway of the immune system and deliver a lasting protective immunity. The Mycobacterium recombinant vaccine system for treatment of intracellular diseases utilizes antigen delivery systems in the form of non pathogenic Mycobacterium strains, genetic transfer systems in the form of cloning and expression vectors, and related technologies to provide products containing non toxic immuno-regulating Mycobacterium adjuvants, non toxic immuno-stimulating exogenous antigens specific for a variety of diseases, and non toxic amounts of cytokines that boost the TH-1 pathway. The cloning and expression Mycobacterium vectors include both pAL5000-based extra-chromosomal and D29-based integrative vectors.

Cloning and DNA sequence of the Mycobacterium fortuitum var fortuitum plasmid pAL5000.

The complete nucleotide sequence of the Mycobacterium fortuitum var fortuitum plasmid pAL5000 has been determined. Computer analysis of this 4821-bp plasmid for protein coding regions, based on mycobacterial codon usage preferences, reveals the presence of two putative protein coding regions immediately downstream from typical mycobacterial promoter and ribosome binding sites. Both open reading frames, ORF1 and ORF2, produced proteins with the predicted respective sizes previously shown in minicell expression experiments [A. Labidi et al. (1985) FEMS Microbiol. Lett. 30, 221-225]. ORF1 encodes a putative 20-kDa basic protein with characteristics of a DNA binding protein involved in plasmid DNA replication. ORF2 encodes a 67-kDa protein with an amino-terminal sequence suggestive of a transported protein and a possible transmembrane anchor near its carboxyl-terminal. The current sequence and its analysis are more consistent with the minicell expression experiments than the previously published sequence of the pAL5000 plasmid [J. Rauzier et al. (1988) Gene 71, 315-321].

BRO beta-lactamases of Branhamella catarrhalis and Moraxella subgenus Moraxella, including evidence for chromosomal beta-lactamase transfer by conjugation in B. catarrhalis, M. nonliquefaciens, and M. lacunata.

Two closely related beta-lactamases, BRO-1 and BRO-2 (formerly called Ravasio and 1908), are found in Moraxella (Branhamella) catarrhalis. We screened strains of B. catarrhalis recovered in the United States since 1952 and identified the first beta-lactamase-positive isolate in August 1976. The prevalence of the enzymes among 394 clinical isolates from one Texas hospital has averaged 75% since testing began in 1983. Screening of isolates of Moraxella subgenus Moraxella revealed the BRO enzymes in two other human respiratory tract species, M. lacunata and M. nonliquefaciens, beginning in 1978. A different beta-lactamase with a pI of 6.4 predominated in other species of subgenus Moraxella. BRO-2 had a different isoelectric focusing pattern and was produced in lesser amounts than BRO-1, but the two enzymes were indistinguishable by substrate or inhibitor profile. BRO enzymes from B. catarrhalis, M. nonliquefaciens, and M. lacunata could be transferred by conjugation and, for B. catarrhalis, also by transformation to B. catarrhalis. Plasmid bands were demonstrated in 90% of M. nonliquefaciens and in one previously reported strain of B. catarrhalis, but no change in plasmid profiles was seen in beta-lactamase-positive recombinants, supporting previous studies that suggested the beta-lactamase genes are chromosomal.

Heterogeneity among isolates of rapidly growing mycobacteria responsible for infections following augmentation mammaplasty despite case clustering in Texas and other southern coastal states.

Thirty-seven cases of rapidly growing mycobacterial wound infections following augmentation mammaplasty were identified between 1979 and 1988. The infections were usually unilateral and had a narrow geographic distribution: almost 60% were from Texas and 92% from five southern coastal states. In Texas a seasonal incidence was observed; 45% of all previously reported and current patients had undergone mammaplasty in April, May, or June. Although these findings suggested a possible common source, analysis of 35 available isolates revealed 19 different phenotype patterns. Five different taxonomic groups were represented, although most isolates (70%) were Mycobacterium fortuitum biovar fortuitum. Plasmid bands were identified in 10 of 15 strains studied, with nine different profiles. An additional 11 cases of breast infection due to rapidly growing mycobacteria not associated with augmentation were also identified, of which nine came from the same states that contributed mammaplasty cases. Rapidly growing mycobacterial infections of the breast are endemic in Texas and other southern coastal states, and the heterogeneity of the isolates suggests that most cases are unrelated.

Diversity and sources of rapidly growing mycobacteria associated with infections following cardiac surgery.

Eighty-nine isolates of rapidly growing mycobacteria associated with cardiac bypass-related infections were characterized. Isolates from sporadic infections belonged to eight taxonomic groups and displayed numerous multilocus enzyme genotypes, plasmid profiles, and heavy metal and antibiotic resistance patterns. Compared with 449 noncardiac wound isolates, 45 sporadic cardiac isolates were more likely to be Mycobacterium fortuitum and M. smegmatis and less likely to be M. chelonae. About 80% of cardiac and noncardiac isolates were from southern coastal states. Eight outbreaks of cardiac bypass-related infections were identified. Strains from each outbreak were genotypically distinctive, and five outbreaks involved more than one strain. In two outbreaks, isolates from environmental sources and noncardiac infections were similar or identical to isolates from sternal wound infections. The heterogeneity of these isolates suggests that most isolates are unrelated and are derived from local environmental sources rather than from contaminated commercial surgical materials or devices.

Genetic relatedness among Mycobacterium tuberculosis and M. bovis.

Total DNA from two slowly-growing pathogenic mycobacterial species propagated in vitro was isolated, digested with each of 34 restriction endonucleases and analyzed by agarose gel electrophoresis. The most resolved patterns for M. tuberculosis (ATCC 27294) and for M. bovis (ATCC 19210) were obtained respectively using (BamHI, DraI, ClaI, EcoRI, EcoRV, HindIII, HpaI, SalI, SmaI, XbaI and XmaI). The patterns produced for these strains were reproducible and distinguishable from each other respectively using (HindIII, DraI, EcoRI, MboI, Sau3AI and AvaI). However, with several enzymes (SalI, AsuI, Sau96I, MspI and HpaII) the patterns for M. tuberculosis and M. bovis were similar. Evidence was obtained for the presence of dam and dcmI methylations in the DNA of each mycobacterial species respectively using (MboI, Sau3AI, EcoRII, BstNI, Sau96I and AsuI).

Genetic relatedness among Mycobacterium paratuberculosis and M. avium complex.

Total DNA was extracted from M. paratuberculosis (ATCC 19698) and from M. avium complex (ATCC 25291) cultivated on RVB-10 enriched liquid media. Restriction endonuclease analysis of total DNA was performed with 34 enzymes and DNA digestion profiles were compared. Fifteen enzymes revealed important differences between the two species. Two pairs of enzymes (EcoRII, BstNI) and (MboI, Sau3AI) provide evidence for the presence of dcmI and dam methylation in DNA of M. avium complex and M. paratuberculosis. The differences in DNA fragments of these two species could be of potential value in differentiating these clinically significant mycobacteria.

Restriction endonuclease analysis of total deoxyribonucleic acid of Mycobacterium tuberculosis H37RV (ATCC 27294) and of M. bovis (ATCC 19210).

Total DNA from two slowly-growing pathogenic mycobacterial species propagated in vitro was isolated, digested with each of 34 restriction endonucleases and analyzed by agarose gel electrophoresis. The most distinct profiles for M. tuberculosis (ATCC 27294) and for M. bovis (ATCC 19210) were obtained respectively using (BamHI, DraI, ClaI, EcoRI, EcoRV, HindIII, HpaI, SalI, SmaI, XbaI, and XmaI). The patterns produced for these strains were reproducible and distinguishable from each other. However, with several enzymes the patterns for M. tuberculosis and M. bovis were similar. Evidence was obtained for the presence of dam and dcmI methylations in the DNA of each mycobacterial species.

Characterization of total deoxyribonucleic acid of Mycobacterium paratuberculosis (ATCC 19698) and of M. avium complex (ATCC 25291) using restriction enzymes.

Total DNA was extracted from M. paratuberculosis (ATCC 19698) and from M. avium complex (ATCC 25291) cultivated on RVB-10 enriched liquid media. Restriction endonuclease analysis was conducted of Total DNA using 34 enzymes and DNA digestion profiles were compared. Fifteen enzymes revealed important differences between the two species. Two pairs of enzymes (EcoRII, BstNI) and (MboI, Sau3AI) provide evidence for the presence of dcmI and dam methylation in DNA of M. avium complex and M. paratuberculosis. The differences in DNA fragments of these two species could be of potential value in differentiating these clinically significant mycobacteria.

Restriction endonuclease mapping and cloning of Mycobacterium fortuitum var. fortuitum plasmid pAL5000.

A restriction map of Mycobacterium fortuitum var. fortuitum plasmid pAL5000 was established. The unique sites for ApaI, BamHI, BglII, BstEII, ClaI, EcoRI, EcoRV, HpaI, KpnI and NarI were located on the 5.0-Kb plasmid. The plasmid had no sites for AhaIII, BclI, HindIII, PstI, SphI and XbaI. pAL5000 was cloned into pBR322 and propagated in Escherichia coli. Three hybrid pAL5000-pBR322 plasmids carrying the complete pAL5000 sequence were constructed by joining the plasmids at their BamHI, EcoRI or EcoRV sites. We also cloned into these plasmids a 1489-bp DNA fragment conferring resistance to kanamycin and originating from the streptococcal plasmid pJH1. The construction of these plasmids will facilitate the analysis and manipulation of pAL5000, and may allow the development of a vector system for genetic analysis in mycobacteria.

[Gonococcus producers of beta-lactamase isolated in Dakar. Sensitivity to different antibiotics, auxotype and plasmid content]. / A propos des gonocoques producteurs de bêtalactamase isolés à Dakar. Sensibilité à divers antibiotiques, auxotype et contenu plasmidique.

More than 12.5% of gonococci isolated in Dakar during the first six months of 1984 were penicillinase producers (PPNG). PPNG strains were susceptible to a number of antibiotics: spectinomycin, thiamphenicol and tetracycline. No significant differences were found between distribution of auxotypes in PPNG and in non-penicillinase producing strains. Study of plasmidic content of PPNG (36 strains isolated from 1981 to 1984) revealed that 68.75% were of the "African" type and 31.25% of the "South-East Asian" type. Ratio of isolation of these two plasmidic content types remained consistent throughout the last four years. The criteria defined in 1977 to classify PPNG into two types need to be reviewed, specifically with regard to geographical areas, auxotype and tetracycline susceptibility. We found a significant correlation between the 4.5 Md plasmid (bla+) and the auxotype (PRO-). This finding has been reported by other authors but has not yet been explained.

[Epidemiological surveillance of beta-lactamase-producing gonococci. II--Characterization of plasmids of 66 strains isolated in France (May 1979-March 1983)]. / Surveillance épidémiologique des gonocoques producteurs de bêta-lactamase. II--Caractérisation des plasmides de 66 souches isol7es en France (mai 1979 - mars 1983).

Penicillinase producing Neisseria gonorrhoeae PPNG (66 strains have been examined for the presence of plasmids coding for bêta-lactamase. The 3.2 Mdal plasmid was present in 27/66 (41%) of strains. The 4.5 Mdal plasmid was present in 30/66 (45%) of strains. The association 2.6 Mdal 4.5 Mdal plasmids were only present in 9/66 (13.6%) of strains. The cryptic plasmid of 2.6 Mdal was always present.