Aspects épidemiologiques et cliniques des mycoses superficielles en milieu hospitalier à Cotonou de 2005 à 2014

Introduction : Les mycoses superficielles sont fréquentes en zones tropicales et représentent le premier motif de consultation en dermatologie dans de nombreux pays africains. Matériel et méthodes : Une étude rétrospective, descriptive et analytique a été réalisée dans le service de Dermatologie du Centre National Hospitalier et Universitaire de Cotonou pour décrire le profil épidémiologique et clinique des mycoses superficielles. Elle a inclus sur 10 ans tous les patients chez qui un diagnostic clinique de mycose superficielle a été retenu. Résultats : La prévalence des mycoses superficielles était de 9,6% (1037/10787 patients). Les deux sexes étaient uniformément représentés et l'âge moyen était de 32,2 ans. Trois groupes cliniques de mycoses superficielles étaient retrouvés : dermatophytoses (44,7%), candidoses cutanéo-muqueuses (32,8%) et pityriasis versicolor (31,3%). Les épidermomycoses (93,4%) étaient réparties en dermatophytoses de la peau glabre et des plis (36,4%), pityriasis versicolor (31,3%) et candidoses des plis (25,7%). Les onychomycoses (9,7%) étaient soit de suspicion candidosique (6,4%) ou soit dermatophytique (3,3%). Les teignes représentaient 5% de l'ensemble des mycoses superficielles et la candidose muqueuse 0,7%. Les principaux facteurs favorisants identifiés étaient l'utilisation abusive des savons antiseptiques (20,4%) et l'usage à visée cosmétique de produits dépigmentants (12,7%). Conclusion : Les mycoses superficielles étaient fréquentes avec une prédominance des épidermomycoses dans le service de dermatologie de Cotonou. Les habitudes cosmétiques représentaient un important facteur favorisant de ces épidermomycoses

Zona en milieu hospitalier à Cotonou de 2005 à 2014: aspects épidemiologiques et cliniques

L'objectif de cette étude était de documenter les aspects épidémiologiques et cliniques du zona en milieu hospitalier à Cotonou. Matériel et méthodes : L'étude était rétrospective et descriptive sur 10 ans et a concerné tous les nouveaux patients reçus en consultation dans le service de Dermatologie du Centre National Hospitalier et Universitaire de Cotonou (CNHU-C), chez qui le diagnostic clinique de zona a été retenu. Résultats : Sur les 10787 nouveaux patients reçus durant la période, 70 présentaient un zona correspondant à une prévalence de 0,6%. Le sex-ratio H/F était de 1,1. La moyenne d'âge était de 42,3 ans avec des extrêmes de 1 an et 73 ans. La tranche d'âge la plus touchée était celle des patients de 50-60 ans. L'infection à VIH était associée au zona dans 46,9% des cas. Les formes érythémato-vésiculeuses à disposition unilatérale étaient prédominantes (79%). Les formes nécrotiques (10%) et nécrotico-hémorragiques (4%) étaient l'apanage des patients infectés par le VIH. Conclusion : Le zona était une dermatose rare dans le service de dermatologie du CNHU- C. L'immunodéficience par le VIH et l'immunosénescence étaient les principaux facteurs de co-morbidité

Transient thermal dissipation method for xylem sap flow measurement: implementation with a single probe.

Comparisons of tree water relations between treatments, species and sites are facilitated by the use of simple and low-cost measurements of xylem sap flow rates. The transient thermal dissipation (TTD) method is a variant of the constant thermal dissipation (CTD) method of Granier. It has the advantages of limiting thermal interference and of saving electrical energy. Here, our concern was to test a new step towards simplicity and low cost: the applicability of the TTD method with a single probe, i.e., without a reference sensor, following a cycle of 10 min heating and 10 min cooling, and using the same thermal index and multi-species calibration previously assessed with a dual probe. First, the responses of the dual and single probes were compared in an artificial hydraulic column of sawdust in the laboratory over a complete range of flux densities, from 0.3 to 4.0 l dm⁻² h⁻¹. Second, diurnal kinetics were compared in a young tree with rapid changes in the sapwood reference temperature of up to 5 °C h⁻¹ for 5 consecutive days. With a relatively stable reference temperature, laboratory results showed that a single probe yielded the same temperature signal and thermal index as a dual probe for the full range of sap flux densities. Within the tree, the cooled temperature of the heated probe, linearly interpolated, proved to be an accurate indicator of the change in the reference temperature over time. Logically, the temperature signals and estimates of sap flux density with the single probe did not differ from the dual-sensor measurements when the cooled temperature was interpolated. Additionally, the responses of the thermal index, yielded in the hydraulic experiment with the sawdust column, fell within the variability of the multi-species calibration. This result supports the previous assessment of a non-species-specific calibration for the TTD method with diffuse porous media. In conclusion, our results showed that the TTD method can be directly applied with a single probe. Limitations and possible future progress are pointed out. This measurement system is probably the simplest technique currently available to measure xylem sap flow.

Transient thermal dissipation method of xylem sap flow measurement: multi-species calibration and field evaluation.

The transient thermal dissipation (TTD) method developed by Do and Rocheteau (2002b) is a close evolution of the original constant thermal dissipation (CTD) method of Granier (1985). The TTD method has the advantage of limiting the influence of passive natural temperature gradients and of yielding more stable zero-flux references at night. By analogy with the CTD method, the transient method was first calibrated on synthetic porous material (sawdust) on the assumption that the relationship was independent of the woody species. Here, our concern was to test the latter hypothesis with a 10-min heating time in three tropical species: Hevea brasiliensis Müll. Arg., Mangifera indica L. and Citrus maxima Merr. A complementary objective was to compare the field estimates of daily transpiration for mature rubber trees with estimates based on a simplified soil water balance in the dry season. The calibration experiments were carried out in the laboratory on cut stems using an HPFM device and gravimetric control of water flow up to 5 L dm(-2) h(-1). Nineteen response curves were assessed on fully conductive xylem, combining 11 cut stems and two probes. The field evaluation comprised five periods from November 2007 to February 2008. Estimates of daily transpiration from the measurement of sap flow were based on the 41 sensors set up on 11 trees. Soil water depletion was monitored by neutron probe and 12 access tubes to a depth of 1.8 m. The calibrations confirmed that the response of the transient thermal index to flow density was independent of the woody species that were tested. The best fit was a simple linear response (R(2) = 0.88, n = 276 and P < 0.0001). The previous calibration performed by Do and Rocheteau (2002b) on sawdust fell within the variability of the multi-species calibration; however, there were substantial differences with the average curve at extreme flow rates. Field comparison with soil water depletion in the dry season validated to a reasonable extent the absolute estimates of transpiration acquired with the 10-min TTD method. In conclusion, evidence for the independence of calibration from woody species and the simple linear response of the thermal index strengthen the interest of the TTD method with 10-min heating.

A inter-relação ortodontia/periodontia em pacientes adultos / Interrelationship between orthodontics and periodontology in adult patients

A movimentação dentária em pacientes adultos com periodonto reduzido necessita de uma estreita associação entre a Periodontia e a Ortodontia, permitindo aos pacientes uma melhora das condições de saúde bucal, através de benefícios advindos da atuação combinada dessas duas especialidades. O objetivo deste artigo é discutir como os conceitos vigentes nessas áreas podem ser utilizados para melhorar o plano de tratamento, o comportamento clínico e a manutenção desses pacientes, nos quais diferentes formas de maloclusão são gerados ou agravadas pela descrição periodontal moderada ou avançada. Portanto, a avaliação clínica da condição periodontal do paciente a ser submetido ao tratamento ortodôntico deve ser realizada, minunsiosamente, pelo ortotontista e periodontista, estabelecendo um programa efetivo da manutenção da saúde de tecidos, assegurando mínimos danos aos mesmos durante a terapia ortodôntica. Essa avaliação deve envolver a análise do aspecto tecidual (cor, textura e grau de plasticidade), da severidade da inflação (sangramento e sondagem espontâneo; presença de superação) e das mudanças no nível de inserção dos tecidos moles (regressão gengival) e dos tecidos duros (perda óssea horizontal, profundidade da bolsa periodontal), a fim de estabelecer-se um adequado diagnóstico e plano de tratamento. Os apectos mecânicos da terapia ortodôntica também deve ser criteriosamente analisados. Deste modo, sistemas de forças ideais devem ser individualizados para cada caso, por meio da utilização de dispositivos que apliquem forças compatíveis com a estrutura periodontal debilitada apresentada pelo paciente

Influence of natural temperature gradients on measurements of xylem sap flow with thermal dissipation probes. 1. Field observations and possible remedies.

The thermal dissipation method is simple and widely used for measuring sap flow in large stems. As with several other thermal methods, natural temperature gradients are assumed to be negligible in the sapwood being measured. We studied the magnitude and variability of natural temperature gradients in sapwood of Acacia trees growing in the Sahelian zone of Senegal, analyzed their effects on sap flow measurements, and investigated possible solutions. A new measurement approach employing cyclic heating (45 minutes of heating and 15 minutes of cooling; 45/15) was also tested. Three-day measurement sequences that included 1 day without heating, a second day with continuous heating and a third day with cyclic heating were recorded during a 6.5-month period using probes installed at three azimuths in a tree trunk. Natural temperature gradients between the two probes of the sensor unit, spaced 8 to 10 cm vertically, were rarely negligible (i.e., < 0.2 degrees C): they were positive during the night and negative during the day, with an amplitude ranging from 0.3 to 3.5 degrees C depending on trunk azimuth, day and season. These temperature gradients had a direct influence on the signal from the continuously heated sensors, inducing fluctuations in the nighttime reference signal. The resulting errors in sap flow estimates can be greater than 100%. Correction protocols have been proposed in previous studies, but they were unsuitable because of the high spatial and temporal variability of the natural temperature gradients. We found that a measurement signal derived from a noncontinuous heating system could be an attractive solution because it appears to be independent of natural temperature gradients. The magnitude and variability of temperature gradients that we observed were likely exacerbated by the combination of open stand, high solar radiation and low sap flow rate. However, for all applications of the thermal dissipation method, it is wise to check regularly for natural temperature gradients by switching off the heater.

Influence of natural temperature gradients on measurements of xylem sap flow with thermal dissipation probes. 2. Advantages and calibration of a noncontinuous heating system.

Natural temperature gradients in stems of trees growing in open stands give rise to errors when measuring sap flow by the continuous thermal dissipation method. Previously, we obtained evidence from field measurements that a noncontinuous thermal dissipation system can prevent these errors (Do and Rocheteau 2002). Cyclic heating (i.e., 45 minutes on and 15 minutes off; 45/15) allowed the derivation of an alternate signal, defined as the difference between the temperature signal at the end of the heating period and the temperature signal at the end of the cooling period. By analogy with the continuous system, we calculated an alternate flow index. Analysis in an artificial flow system confirmed that external temperature gradients have an additive effect on the continuous signal, whereas the alternate signal is unaffected by such gradients. The response of the alternate flow index to flow densities was similar for five combinations of heating and cooling times (45/15, 40/20, 30/30, 15/15 and 10/10 min). The relationship was markedly different from Granier's (1985) calibration because measurements in cyclic systems are made under non-steady-state temperature conditions. We recommend the 15/15 min cycle, which allows two sap flow measurements per hour. We compared flow density estimates obtained from field measurements with the continuous and cyclic systems over 192 days with 1-day lags between systems. Comparisons based on daily maximum values (between 0.5 and 2.5 l dm(-2) h(-1) for the cyclic system) confirmed that differences between the continuous and cyclic systems, which could be greater than 100%, were linked to the effect of temperature gradients on the continuous system. The results demonstrate that, in situations where significant natural temperature gradients (i.e., > 0.2 degrees C) are likely, the cyclic system improves the accuracy of sap flow measurements made with thermal dissipation probes.

Cadmium uptake by hydroxyapatite synthesized in different conditions and submitted to thermal treatment.

This paper intends to evaluate the uptake of cadmium ions from aqueous solution by 21 hydroxyapatite samples which have been synthesized in different conditions. It has been determined thatthe variation on the hydroxyapatite sorption capacity is neither related to sample solubility nor to hydroxyapatite Ca/P molar ratio. Cd2+ sorption is controlled by sample BET surface area, which shows a direct dependence on the hydroxyapatite crystallite dimensions. The hydroxyapatite pore distribution presented modes at 1000 and 60,000 A, corresponding to intracrystallite voids and voids between the agglomerate of these crystallites, respectively. Pores belonging to the former mode immobilize the major part of Cd2+. The influence of sample thermal treatment on Cd2+ sorption efficiency has been studied using hydroxyapatite samples calcined at temperatures ranging from 500 to 1140 degrees C. Similarly to nonthermally treat samples, the Cd2+ sorption on calcined hydroxyapatite could be described by Langmuir isotherms. The results showed that the maximum sorption capacity decreased from 0.631 mmol g(-1) for the noncalcined sample to 0.150 mmol g(-1) for the one calcined at 900 degrees C. This drop in the sorption capacity could also be explained by a reduction in its specific surface area, which is induced bythe increase of the crystal size.

Synthesis and antiviral activity of monobactams inhibiting the human cytomegalovirus protease.

A series of monobactam inhibitors of HCMV (N(o)) protease bearing a heterocycle linked by a methylene group at C-4 is described. Inhibitors containing a heterocycle such as a 2-furyl, 2-thiophenyl, 4-methyl-2-tetrazole and 2-benzothiazole were found to be active in a plaque reduction assay. Furthermore, 2-benzothiazole derivatives were shown to inhibit the HCMV protease activity inside cells by using a cell transfection assay, indicating that their antiviral activity in the plaque reduction assay could be attributed to protease inhibition.

Self-association of herpes simplex virus type 1 ICP35 is via coiled-coil interactions and promotes stable interaction with the major capsid protein.

The ordered copolymerization of viral proteins to form the herpes simplex virus (HSV) capsid occurs within the nucleus of the infected cell and is a complex process involving the products of at least six viral genes. In common with capsid assembly in double-stranded DNA bacteriophages, HSV capsid assembly proceeds via the assembly of an outer capsid shell around an interior scaffold. This capsid intermediate matures through loss of the scaffold and packaging of the viral genomic DNA. The interior of the HSV capsid intermediate contains the viral protease and assembly protein which compose the scaffold. Proteolytic processing of these proteins is essential for and accompanies capsid maturation. The assembly protein (ICP35) is the primary component of the scaffold, and previous studies have demonstrated it to be capable of intermolecular association with itself and with the major capsid protein, VP5. We have defined structural elements within ICP35 which are responsible for intermolecular self-association and for interaction with VP5. Yeast (Saccharomyces cerevisiae) two-hybrid assays and far-Western studies with purified recombinant ICP35 mapped a core self-association domain between Ser165 and His219. Site-directed mutations in this domain implicate a putative coiled coil in ICP35 self-association. This coiled-coil motif is highly conserved within the assembly proteins of other alpha herpesviruses. In the two-hybrid assay the core self-association domain was sufficient to mediate stable self-association only in the presence of additional structural elements in either N- or C-terminal flanking regions. These regions also contain conserved sequences which exhibit a high propensity for alpha helicity and may contribute to self-association by forming additional short coiled coils. Our data supports a model in which ICP35 molecules have an extended conformation and associate in parallel orientation through homomeric coiled-coil interactions. In additional two-hybrid experiments we evaluated ICP35 mutants for association with VP5. We discovered that in addition to the C-terminal 25 amino acids of ICP35, previously shown to be required for VP5 binding, an additional upstream region was required. This region is between Ser165 and His234 and contains the core self-association domain. Site-directed mutations and construction of chimeric molecules in which the self-association domain of ICP35 was replaced by the GCN4 leucine zipper indicated that this region contributes to VP5 binding through mediating self-association of ICP35 and not through direct binding interactions. Our results suggest that self-association of ICP35 strongly promotes stable association with VP5 in vivo and are consistent with capsid formation proceeding via formation of stable subassemblies of ICP35 and VP5 which subsequently assemble into capsid intermediates in the nucleus.

Microtube batch protein crystallization: applications to human immunodeficiency virus type 2 (HIV-2) protease and human renin.

For therapeutically relevant targets, the evaluation of enzymes in complex with their inhibitors by cocrystallization and high resolution structural analysis has become a vital component of structure-driven drug design and development. Two approaches, hanging drop vapor diffusion and a novel microtube batch method, were utilized in parallel to grow crystals of recombinant HIV-2 protease and recombinant human renin in complex with inhibitors. In the case of HIV-2 protease in complex with a reduced amide inhibitor, crystallization was achieved only by the microbatch method. In the case of human renin, the addition of precipitant was required for crystal growth. The microbatch method described here is a useful supplementary or alternative approach for screening parameters and generating crystals suitable for high resolution structural analysis.

Crystal structure of human immunodeficiency virus (HIV) type 2 protease in complex with a reduced amide inhibitor and comparison with HIV-1 protease structures.

The crystal structure of HIV-2 protease in complex with a reduced amide inhibitor [BI-LA-398; Phe-Val-Phe-psi (CH2NH)-Leu-Glu-Ile-amide] has been determined at 2.2-A resolution and refined to a crystallographic R factor of 17.6%. The rms deviation from ideality in bond lengths is 0.018 A and in bond angles is 2.8 degrees. The largest structural differences between HIV-1 and HIV-2 proteases are located at residues 15-20, 34-40, and 65-73, away from the flap region and the substrate binding sites. The rms distance between equivalent C alpha atoms of HIV-1 and HIV-2 protease structures excluding these residues is 0.5 A. The shapes of the S1 and S2 pockets in the presence of this inhibitor are essentially unperturbed by the amino acid differences between HIV-1 and HIV-2 proteases. The interaction of the inhibitor with HIV-2 protease is similar to that observed in HIV-1 protease structures. The unprotected N terminus of the inhibitor interacts with the side chains of Asp-29 and Asp-30. The glutamate side chain of the inhibitor forms hydrogen bonds with the main-chain amido groups of residues 129 and 130.