[Kerion Celsi due to Microsporum canis infection]. / Kerion Celsi durch Microsporum canis.

Tinea capitis is seen world-wide among children up to 12 years. The most severe type is Kerion Celsi with painful abscesses and lymphadenopathy. We report on an 11-year-old boy with Kerion Celsi, who was initially treated using antibiotics under the common misdiagnosis of a bacterial infection. Mycological investigations could identify Microsporum canis. The patient was treated orally with griseofulvin, which resulted in complete mycological remission after 8 weeks. Cicatrical alopecia, however, could not be prevented. Purulent infections of the scalp should lead to early mycological diagnostics in children.

Soil mite communities (Acari: Mesostigmata) as indicators of urban ecosystems in Bucharest, Romania.

The aim of the present study was to establish the effect of management type and of environmental variables on the structure, abundance and species richness of soil mites (Acari: Mesostigmata) in twelve urban green areas in Bucharest-Romania. Three categories of ecosystem based upon management type were investigated: protected area, managed (metropolitan, municipal and district parks) and unmanaged urban areas. The environmental variables which were analysed were: soil and air temperature, soil moisture and atmospheric humidity, soil pH and soil penetration resistance. In June 2017, 480 soil samples were taken, using MacFadyen soil core. The same number of measures was made for quantification of environmental variables. Considering these, we observed that soil temperature, air temperature, air humidity and soil penetration resistance differed significantly between all three types of managed urban green area. All investigated environmental variables, especially soil pH, were significantly related to community assemblage. Analysing the entire Mesostigmata community, 68 species were identified, with 790 individuals and 49 immatures. In order to highlight the response of the soil mite communities to the urban conditions, Shannon, dominance, equitability and soil maturity indices were quantified. With one exception (numerical abundance), these indices recorded higher values in unmanaged green areas compared to managed ecosystems. The same trend was observed between different types of managed green areas, with metropolitan parks having a richer acarological fauna than the municipal or district parks.

[Incidence of tuberculous infection in Caracal in 2000]. / Incidenta infectiei tuberculoase în municipiul Caracal în anul 2000.

Taking into consideration the informational value of the yearly risk of tuberculous infection as an isolated epidemic indicator which is able to define by itself the present phase and the trends of the tuberculous endemic in a population, we tried to establish its value at the first grade pupils in the city of Caracal by using two methods: 1. the indirect one starting from the prevalence of infection using the A. Lotte formula: YRI = 1.24% +/- 0.45, p = 0.05, s = 0.32, Es = 0.16 (the average level in 1992, 1993, 1994, 1999 and 2000); 2. the direct one, by testing with tuberculin a group of 184 pupils twice at one year's interval. YRI = 2.65% in 1999/2000. By using the student test we demonstrated that the two values are statistically different, without being able to state which one is closer to reality, but irrespective of the chosen value, to reach the present level of yearly tuberculous infection of the western countries we need about ten to twenty years, if we admit that beginning from this moment the annual decrease will be maximal (14%).

Insights into transition state stabilization of the beta-1,4-glycosidase Cex by covalent intermediate accumulation in active site mutants.

The catalytic mechanism of 'retaining' beta-glycosidases has been the subject of considerable interest and debate for many years. The visualization of a covalent glycosyl enzyme intermediate by X-ray crystallography was first accomplished with a saccharide substrate substituted with fluorine at its 2-position. The structure implicated major roles for residue His 205 and for the 2-hydroxyl position of the proximal saccharide in binding and catalysis. Here we have studied the kinetic behavior of various His 205 mutants. One of these mutants, a double mutant H205N/E127A, has been used to stabilize a covalent glycosyl-enzyme intermediate involving an unsubstituted sugar, permitting crystallographic analysis of the interactions between its 2-hydroxyl group and the enzyme.

Exploring the cellulose/xylan specificity of the beta-1,4-glycanase cex from Cellulomonas fimi through crystallography and mutation.

The retaining beta-1,4-glycanase Cex from Cellulomonas fimi, a family 10 glycosyl hydrolase, hydrolyzes xylan 40-fold more efficiently than cellulose. To gain insight into the nature of its preference for xylan, we determined the crystal structure of the Cex catalytic domain (Cex-cd) trapped as its covalent 2-deoxy-2-fluoroxylobiosyl-enzyme intermediate to 1.9 A resolution. Together with the crystal structure of unliganded Cex-cd [White, A., et al. (1994) Biochemistry 33, 12546-12552] and the previously determined crystal structure of the covalent 2-deoxy-2-fluorocellobiosyl-Cex-cd intermediate [White, A., et al. (1996) Nat. Struct. Biol. 3, 149-154], this structure provides a convincing rationale for the observed substrate specificity in Cex. Two active site residues, Gln87 and Trp281, are found to sterically hinder the binding of glucosides and must rearrange to accommodate these substrates. Such rearrangements are not necessary for the binding of xylobiosides. The importance of this observation was tested by examining the catalytic behavior of the enzyme with Gln87 mutated to Met. This mutation had no measurable effect on substrate affinity or turnover number relative to the wild type enzyme, indicating that the Met side chain could accommodate the glucoside moiety as effectively as the wild type Gln residue. Subsequent mutagenesis studies will address the role of entropic versus enthalpic contributions to binding by introducing side chains that might be more rigid in the unliganded enzyme.