Identification of infectious Pseudomonas aeruginosa strains in an occupational saturation diving environment

OBJECTIVES: Occupational saturation divers have various skin disorders, of which skin infections are the most serious and frequent. Pseudomonas aeruginosa is the microbe most often isolated from skin infections in divers. The purpose of the present work was (a) to report the occurrence of P aeruginosa in skin infections in operational saturation diving in the North Sea from 1987 to 1995; (b) to report the environmental occurrence of P aeruginosa in saturation diving systems, and finally (c) to identify possible relations between infection related to strains of P aeruginosa and environmental isolates of the microbe. RESULTS: During the period 1987-95, P aeruginosa was isolated from 257 skin infections in operational saturation divers. Most of the isolates related to infection by P aeruginosa show a unique growth inhibition pattern towards the normal skin flora, and the serotype pattern of P aeruginosa from skin infections is limited compared with similar infections in non-divers. In a mini-epidemiological study on board one diving vessel during one operational diving period, five significantly different DNA fragment profiles were found among the 12 isolates related to infection by P aeruginosa obtained from the saturation system. In two cases the infectious genotypes were detected in the fresh water for the saturation chambers weeks before the arrival of the infected diver. CONCLUSIONS: The most commonly used epidemiological marker for P aeruginosa world wide, also used in earlier studies, is serotyping, but with pulsed field gel electrophoresis (PFGE) miniepidemiology it was shown to be insufficient for epidemiological purposes in saturation environments. PFGE analyses were shown to be superior both to antibacterial factor and to serotyping in epidemiological analyses of P aeruginosa infections in saturation diving.     

Mice lacking E-selectin show normal numbers of rolling leukocytes but reduced leukocyte stable arrest on cytokine-activated microvascular endothelium

OBJECTIVE: Previous work indicated that E-selectin mediates transient interactions between leukocytes and cytokine-activated endothelium in vitro. Here we examine the role of E-selectin in blood leukocyte interactions with microvascular endothelium in vivo. METHODS: E-selectin-deficient (E-/-) mice were produced by gene targeting. The effect of this null mutation on leukocyte-endothelial interactions was determined by intravital microscopy before and 4 to 5 hours after local administration of the proinflammatory cytokine tumor necrosis factor alpha (TNF alpha) in dermal microvessels with low blood flow (dorsal skin-fold chambers, intact ear skin), and after endotoxin activation in exteriorized mesenteric microvessels with higher blood flow. RESULTS: E-/- mice were viable, fertile with normal circulating leukocyte and platelet profiles. Approximately 60% of circulating leukocytes rolled in dermal microvessels of both normal (E+/+) and E-/- mice without inflammatory stimulation. After local administration of TNF alpha, rolling increased modestly and equivalently in both genotypes. The main effect of TNF alpha was a dramatic increase in leukocyte stable adhesion and, unlike rolling, this manifestation of endothelial activation was significantly reduced in E-/- animals. This reflected fewer dermal microvessels supporting higher adhesion densities in E-/- mice, and a similar trend was observed in mesenteric microvessels. CONCLUSIONS: E-selectin plays a previously unappreciated role in facilitating and/or mediating stable adhesion of leukocytes to inflamed microvascular endothelium.     

Diver''s hand: a skin disorder common in occupational saturation diving

We describe the prenatal ultrasonographic features that led to the diagnosis of a lingual lymphangioma. The risk of upper airway obstruction, which is associated with this rare abnormality, prompted us to plan careful perinatal management. We believe that, in cases of suspected lymphangioma of the tongue or other oropharyngeal tumors, elective delivery should be carried out in a tertiary referral center in which emergency ventilation and tracheostomy are possible.     

Interleukin-12 enhances CD26 expression and dipeptidyl peptidase IV function on human activated lymphocytes

Research of a cellular pathway activated by IL-12 which may result in new therapeutical approaches for IL-12, led us to find an intriguing relationship between IL-12 and CD26/DPPIV ectopeptidase on activated T cells. Both the percentage and median fluorescence intensity (MFI) of CD26+ cells in the PHA-stimulated PBMC or lymphoblasts increased when IL-12 (optimum dose, 2 ng/ml) was present. Maximum CD26 expression was observed on day-2 cultures of lymphoblasts, the presence of IL-12 receptor probably being necessary for this upregulation. In addition, CD26 upregulation correlated with enhanced DPPIV function. Enzyme affinity and secretion of the soluble form of DPPIV were not affected by IL-12. Kinetic behaviours of Ag expression and enzymatic activity support a different CD26 regulation pathway by IL-12. These data suggest that the correlation found in vivo between the CD26 expression and Th1-like immune responses is due to this IL-12-dependent upregulation.     

Sperm immobilizing activity of a synthetic bioactive peptide 20-44 of 37-kDa cationic antimicrobial protein (CAP37) of human neutrophils

We have previously reported that human sperm coincubated with human peripheral blood neutrophils in the presence of complement (C)-fixing antisperm antibody (ASA)-positive sera are rapidly internalized and degraded within the neutrophil phagolysosome. However, the mechanism by which motile sperm are processed within the phagolysosome is unknown. Various spermicidal/antimicrobial proteins contained in azurophilic granules that can be secreted into the phagolysosome may play a role in sperm disposal. In this study, we examined the expression of a 37-kDa cationic antimicrobial protein (CAP37) during sperm phagocytosis and the effect of its synthetic bioactive fragment, Peptide 20-44 (P20-44), on sperm motility, acrosomal integrity, and mitochondrial functionality. CAP37 expression by neutrophils undergoing ASA- and C-dependent sperm phagocytosis was increased as measured by flow cytometry. Exposure of motile sperm to a cationic P20-44, the bioactive antimicrobial fragment of CAP37, resulted in the loss of sperm motility without disruption of the acrosomal membrane. The sperm immobilizing activity (SIA) of P20-44 was modulated by the length of incubation, the concentration of the peptide, and the pH of the assay medium. SIA induced by P20-44 was partially reversible and was unaffected by the presence of anionic heparin or seminal plasma. Similar to the antimicrobial activity of P20-44, the SIA was also dependent on the presence of a disulfide bond between cysteine residues at positions 26 and 42 and was inhibited by Lipid A. However, the mechanism of action of P20-44 on sperm is not totally dependent on the molecule's cationicity, because five other cationic antimicrobial peptides had no detectable effect on sperm viability. Thus, the mechanism of action of P20-44 on human sperm is different from its cationic antibactericidal effect. These findings established that motile human sperm are sensitive to CAP37 or its synthetic bioactive peptide and suggested that this protein could play a role in neutrophil-mediated immune destruction of sperm in the female genital tract. P20-44 of CAP37 may be useful in investigating the regulation of human sperm motility and to construct "hybrid peptides" with enhanced potency as a component of vaginal contraceptive that could doubly be effective by killing infectious agents and inhibiting sperm transport.     

The immunochemical approach to the characterization of membrane proteins. Human erythrocyte membrane proteins analysed as a model system

1. Crossed immunoelectrophoresis was used for extensive characterization of individual proteins of human erythrocyte membranes solubilized in non-ionic detergent. 2. The precipitates were assigned to extrinsic or intrinsic proteins. 3. Four glycoproteins were identified by their lectin binding behaviour, whilst five proteins were affected by neuraminidase, indicating them to be sialoglycoproteins. 4. Enzymatic activity is retained in the solubilized system and the presence of acetylcholinesterase and an ATPase was demonstrated. The formation of phosphorylated membrane proteins on incubation with [32P]ATP was demonstrated by autoradiography on the immunoelectrophoresis plates. 5. Five proteins located on the outer cell surface were identified by antibody binding to intact cells. These same proteins were degraded by proteolytic enzymes in intact cells but only three of them were labelled by lactoperoxidase-catalysed 125I-iodination. 6. Analysis of erythrocyte membrane proteins using quantitive immunoelectrophoresis yields results concordant with those obtained by dodecyl sulfate-polyacrylamide gel electrophoresis.     

Primary myxoid leiomyoma of the liver

We describe a case of hepatic leiomyoma in a 41-year-old woman who complained of abdominal discomfort due to a right upper quadrant abdominal mass. A computed tomographic scan revealed a large hepatic mass with unusual cystic change. Light and electron microscopic findings and an immunohistochemical study demonstrated diffuse and scattered proliferation of smooth muscle cells in a myxoid matrix. In contrast to previously reported cases of primary leiomyoma of the liver, the present tumor developed in a patient without an immunosuppressive condition. To the best of our knowledge, this is the first reported case of primary "myxoid" leiomyoma of the liver.