Encapsulation of chemicals in liposomes and microneedling are currently used techniques to enhance the penetration of several substances through skin and hair. In this study, we apply a liposomal melanin–fluorescein compound to an ex vivo model of human skin, using a new electrical microneedling device (Nanopore turbo roller). The product was applied by hand massage (A) or with the assistance of the electrical roller for 2 minutes (B). An additional test was performed free of product and with only the E-roller (C). Histological changes and product absorption were evaluated by optical and fluorescent microscopy 60 and 90 minutes after the treatment. Site B showed larger deposits of melanin–fluorescein at superficial and deep levels of hair structures in comparison to site A. Light, epidermal deposits of the melanin–fluorescein complex were also observed. Sites B and C showed a significant widening (47%) of the follicular infundibulum which could explain the increased penetration of the formulation. Microneedling also removed the scales and sebum residues in the neighborhood of the infundibulum. Targeting hair follicles with melanin may be useful to dye poorly pigmented hairs, improving laser hair removal. The procedure accelerates the delivery of melanin into hair structures allowing an even absorption, larger pigment deposits, and deeper penetration of the formulation into the hair.

Actinobacillus pleuropneumoniae has been considered nonmotile and nonflagellate. In this work, it is demonstrated that A. pleuropneumoniae produces flagella composed of a 65-kDa protein with an N-terminal amino acid sequence that shows 100% identity with those of Escherichia coli, Salmonella, and Shigella flagellins. The DNA sequence obtained through PCR of the fliC gene in A. pleuropneumoniae showed considerable identity (93%) in its 5 and 3 ends with the DNA sequences of corresponding genes in E. coli, Salmonella enterica, and Shigella spp. The motility of A. pleuropneumoniae was observed in tryptic soy or brain heart infusion soft agar media, and it is influenced by temperature. Flagella and motility may be involved in the survival and pathogenesis of A. pleuropneumoniae in pigs.Actinobacillus pleuropneumoniae is a gram-negative bacterium that is the etiologic agent of porcine pleuropneumonia, a disease associated with widespread morbidity and mortality among all ages of growing pigs. Animals become ill and often die due to the fibrino-hemorrhagic lesions produced. Survivors grow poorly and spread the infection to nonimmune herds (3, 16). A. pleuropneumoniae possesses both secreted and nonsecreted virulence factors (6,14,18).A. pleuropneumoniae has been described as a nonmotile organism unable to produce flagellar locomotive appendages (10). A connection between virulence and flagellum-based motility has long been observed for many pathogens which require functional flagella for virulence (9,12,13). Nonmotile flagellated strains and mutants lacking flagellar filaments, as well as aflagellated strains of Campylobacter jejuni, were all rapidly cleared from the intestines following experimental infection of animals (17). However, in some pathogens motility must be suppressed to allow successful colonization (2). For example, Bordetella strains with a wild-type virulence control system, Bvg ϩ strains, are motile under certain conditions, producing peritrichous flagella only in the presence of modulating signals, and they are able to colonize the trachea. However, Bvg Ϫ (⌬bvgAS or ⌬bvgS) strains are motile in the absence of modulators; thus, constitutive expression of this Bvg Ϫ phenotype resulted in a defect affecting colonization (1).This work aims to demonstrate the presence of flagella in A. pleuropneumoniae and their relevance for motility. The Nterminal amino acid sequence of the flagellin of this bacterium and both the 3Ј and 5Ј nucleotide sequences of the gene displayed strong homology with the flagellins and flagellin genes of other gram-negative bacteria, suggesting that flagellin is a conserved protein.Methods. A. pleuropneumoniae serotype 1 (strain BC5235) was isolated from a lung abscess of a pig suffering acute porcine pleuropneumonia (13), and the bacterium was verified by biochemical characteristics and immunological reaction with specific antiserum. This strain and all A. pleuropneumoniae reference strains (15) were maintained on tryptic soy (TS) agar (Bioxón, Oaxaca, Mexico) or brain heart infusi...

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Actin has been described in all eukaryotic cells as the major microfilament cytoskeletal protein. Although prokaryotic cells do not have a cytoskeleton, proteins related to the latter have been found in different prokaryotic species. We have found prokaryotic actin-related proteins in the enterobacterium Escherichia coli and in the cyanobacteria Anabaena cylindrica and Anabaena variabilis. They were identified by the following criteria: (1) by cross-reaction with a fluorescent conjugated anti-actin (rat-brain) mAb by Western blot analysis (in total cellular extracts); (2) specific binding of acetone powder and soluble cellular extracts to DNase 1; and (3) specific binding of cells and total cellular extracts to phalloidin. In E. coli, specific binding of phalloidin labelled with rhodamine to cells was detected by spectrofluorometry. In total cellular extracts, three bands of 60, 43 and 35 kDa were weakly recognized by the mAb by Western blot analysis; this recognition increased when phalloidin was added to the extracts. Furthermore, three polypeptides of 60 kDa were isolated by binding to DNase I, showing pl values of 6.7, 6.65 and 6.6, less acidic than all reported actin pl values. In A. cylindrica and A. variabilis, specific binding of phalloidin labelled with rhodamine to cells was also detected by spectrofluorometry. In total and soluble cellular extracts, the mAb recognized two bands of 45 and 40 kDa by Western blot analysis, but only the first was purified by binding to DNase I, and it showed three isoforms of pl values 6.8, 6.5 and 6.4. These results suggest the presence, in prokaryotes, of proteins with similar biochemical characteristics to eukaryotic actin.

Proteolytic activities of the protozoan parasite Entamoeba histolytica strain HM1:IMSS and the cytochalasin D-resistant mutant BG-3 were analyzed following stimulation with collagen type I and Ca2+, which induces electron-dense associated collagenase secretion. The mutant BG-3 had a protease activity of 73 kDa and secretion of total protease activity was not stimulated by collagen type I and Ca2+, which produced, in contrast, a 2-fold increase in protease secretion by the parental strain. This collagen-stimulated protease secretion was inhibited by cytochalasin D at a concentration of 1 microgram/ml. Cytochalasin D did not have any effect on the protease activity released by the mutant BG-3. These findings suggest that cytoskeleton integrity is necessary for collagen-induced protease secretion.