Inflammatory Myofibroblastic Tumor in the Adrenal Gland: A Case Report.

Inflammatory myofibroblastic tumors (IMTs) were first described by Harold Brunn in 1939. IMTs are mainly found in the lungs and other sites of the body; hence, its occurrence in the adrenal gland is exceptional. In the literature, less than 10 cases of IMTs in the adrenal gland have been reported. The etiology of IMT remains unknown, with post-inflammatory changes and a neoplastic origin being proposed. We present a case of a 19-year-old woman and adrenal gland IMT. The patient presented with abdominal pain and low cardiac output without hypovolemic shock. Computed tomography revealed a tumor in the adrenal gland measuring 11.4 cm with extravasation of contrast medium within the tumor. Treatment included conservative management with selective embolization due to minimal invasion of the inferior artery of the adrenal gland. The patient was then discharged with possibility of future elective surgery. Four months later, the size of the tumor decreased to 6.3 cm, and her Eastern Cooperative Oncology Group physical status was 0. The Multidisciplinary Tumor Board suggested surgical management. The final histopathology report was compatible with an IMT of the adrenal gland, with the immunohistochemical report showing positivity for anti-actin muscle-specific and anti-actin smooth muscle and negativity for anaplastic lymphoma kinase. IMTs of the adrenal gland may be treated electively through multidisciplinary management together with interventional radiology and surgery, achieving a favorable outcome for the patient.

Passage through Tetrahymena tropicalis triggers a rapid morphological differentiation in Legionella pneumophila.

The intracellular bacterial pathogen Legionella pneumophila follows a developmental cycle in which replicative forms (RFs) differentiate into infectious stationary-phase forms (SPFs) in vitro and in vivo into highly infectious mature intracellular forms (MIFs). The potential relationships between SPFs and MIFs remain uncharacterized. Previously we determined that L. pneumophila survives, but does not replicate, while it transiently resides (for 1 to 2 h) in food vacuoles of the freshwater ciliate Tetrahymena tropicalis before being expelled as legionellae-laden pellets. We report here that SPFs have the ability to rapidly (<1 h) and directly (in the absence of bacterial replication) differentiate into MIFs while in transit through T. tropicalis, indicating that SPFs and MIFs constitute a differentiation continuum. Mutant RFs lacking the sigma factor gene rpoS, or the response regulator gene letA, were unable to produce normal SPFs in vitro and did not fully differentiate into MIFs in vivo, further supporting the existence of a common mechanism of differentiation shared by SPFs and MIFs. Mutants with a defective Dot/Icm system morphologically differentiated into MIFs while in transit through T. tropicalis. Therefore, T. tropicalis has allowed us to unequivocally conclude that SPFs can directly differentiate into MIFs and that the Dot/Icm system is not required for differentiation, two events that could not be experimentally addressed before. The Tetrahymena model can now be exploited to study the signals that trigger MIF development in vivo and is the only replication-independent model reported to date that allows the differentiation of Dot/Icm mutants into MIFs.

Packaging of live Legionella pneumophila into pellets expelled by Tetrahymena spp. does not require bacterial replication and depends on a Dot/Icm-mediated survival mechanism.

The freshwater ciliate Tetrahymena sp. efficiently ingested, but poorly digested, virulent strains of the gram-negative intracellular pathogen Legionella pneumophila. Ciliates expelled live legionellae packaged in free spherical pellets. The ingested legionellae showed no ultrastructural indicators of cell division either within intracellular food vacuoles or in the expelled pellets, while the number of CFU consistently decreased as a function of time postinoculation, suggesting a lack of L. pneumophila replication inside Tetrahymena. Pulse-chase feeding experiments with fluorescent L. pneumophila and Escherichia coli indicated that actively feeding ciliates maintain a rapid and steady turnover of food vacuoles, so that the intravacuolar residence of the ingested bacteria was as short as 1 to 2 h. L. pneumophila mutants with a defective Dot/Icm virulence system were efficiently digested by Tetrahymena sp. In contrast to pellets of virulent L. pneumophila, the pellets produced by ciliates feeding on dot mutants contained very few bacterial cells but abundant membrane whorls. The whorls became labeled with a specific antibody against L. pneumophila OmpS, indicating that they were outer membrane remnants of digested legionellae. Ciliates that fed on genetically complemented dot mutants produced numerous pellets containing live legionellae, establishing the importance of the Dot/Icm system to resist digestion. We thus concluded that production of pellets containing live virulent L. pneumophila depends on bacterial survival (mediated by the Dot/Icm system) and occurs in the absence of bacterial replication. Pellets of virulent L. pneumophila may contribute to the transmission of Legionnaires' disease, an issue currently under investigation.

Antioxidant vitamin supplementation reduces benzo(a)pyrene-DNA adducts and potential cancer risk in female smokers.

BACKGROUND: Elevated benzo(a)pyrene [B(a)P]-DNA adducts have been associated with 3-fold increased risk of lung cancer in current smokers. We assessed the chemopreventive effects of antioxidant supplementation using B(a)P-DNA adducts in leukocytes as an intermediate cancer risk marker. METHODS: Subjects were randomized to a double-blinded placebo-controlled clinical trial of antioxidant vitamin supplementation [500 mg vitamin C and 400 IU vitamin E (dl-alpha-tocopherol) daily] or placebo. Smokers with > or =10 cigarettes per day and serum cotinine > or =25 ng/mL were eligible for the study. B(a)P-DNA adduct level was the outcome. The randomization was stratified by gender and cigarettes per day (< or =20 or >20). Smoking habits and blood samples were collected every 3 months during the 15-month treatment period. Samples were analyzed for B(a)P-DNA adducts (high-performance liquid chromatography), plasma cotinine, vitamin levels, and GSTM1 genotype. The intent-to-treat model adjusted for B(a)P-DNA and cotinine at randomization. RESULTS: Overall and among men, there was no effect of treatment on B(a)P-DNA adduct levels. Among treated women, B(a)P-DNA adducts decreased by 31% compared with women on placebo (P = 0.03). Among treated women with the GSTM1 genotype, there was a 43% decrease in adducts (P = 0.04). CONCLUSION: Our primary hypothesis that the mean level of smoking-related B(a)P-DNA adducts would be lower in all subjects in the vitamin treatment group compared with all placebo-treated subjects was not substantiated. However, oursecondary gender-specific analysis found a significant reduction in B(a)P-DNA adducts in women with vitamin treatment, suggesting that antioxidant supplementation maymitigate some of the procarcinogenic effects of exposuretoB(a)P. The effect in GSTM1-null women suggeststhat certain subgroups may derive more benefit fromsupplementation. Although the results of this trial showthe potential chemopreventive role of antioxidants, thebest way for smokers to reduce their cancer risk remains smoking cessation.

Application of an immunoaffinity-based preconcentration method for mass spectrometric analysis of the O-chain polysaccharide of Aeromonas salmonicida from in vitro- and in vivo-grown cells.

In this study, application of magnetic beads (Dynabeads) coated with Aeromonas salmonicida lipopolysaccharide-specific polyclonal antisera to MS-based characterization of bacterial lipopolysaccharides has been evaluated. The results showed that the affinity-based preconcentration strategy resulted in at least a 100-fold increase in the detection of sensitivity, affording direct capillary electrophoresis (CE)-MS analysis of A. salmonicida lipopolysaccharide O-chain polysaccharide from in vitro-cultured cells. Subsequent CE-MS analysis of in vivo-grown cells of A. salmonicida confirmed significant changes in the structure of the lipopolysaccharide O-chain polysaccharide as a result of in vivo cultivation.

Intracellular growth of Legionella pneumophila gives rise to a differentiated form dissimilar to stationary-phase forms.

When Legionella pneumophila grows in HeLa cells, it alternates between a replicative form and a morphologically distinct "cyst-like" form termed MIF (mature intracellular form). MIFs are also formed in natural amoebic hosts and to a lesser extent in macrophages, but they do not develop in vitro. Since MIFs accumulate at the end of each growth cycle, we investigated the possibility that they are in vivo equivalents of stationary-phase (SP) bacteria, which are enriched for virulence traits. By electron microscopy, MIFs appeared as short, stubby rods with an electron-dense, laminar outer membrane layer and a cytoplasm largely occupied by inclusions of poly-beta-hydroxybutyrate and laminations of internal membranes originating from the cytoplasmic membrane. These features may be responsible for the bright red appearance of MIFs by light microscopy following staining with the phenolic Giménez stain. In contrast, SP bacteria appeared as dull red rods after Giménez staining and displayed a typical gram-negative cell wall ultrastructure. Outer membranes from MIFs and SP bacteria were equivalent in terms of the content of the peptidoglycan-bound and disulfide bond cross-linked OmpS porin, although additional proteins, including Hsp60 (which acts as an invasin for HeLa cells), were detected only in preparations from MIFs. Proteomic analysis revealed differences between MIFs and SP forms; in particular, MIFs were enriched for an approximately 20-kDa protein, a potential marker of development. Compared with SP bacteria, MIFs were 10-fold more infectious by plaque assay, displayed increased resistance to rifampin (3- to 5-fold) and gentamicin (10- to 1,000-fold), resisted detergent-mediated lysis, and tolerated high pH. Finally, MIFs had a very low respiration rate, consistent with a decreased metabolic activity. Collectively, these results suggest that intracellular L. pneumophila differentiates into a cyst-like, environmentally resilient, highly infectious, post-SP form that is distinct from in vitro SP bacteria. Therefore, MIFs may represent the transmissible environmental forms associated with Legionnaires' disease.

Expression of magA in Legionella pneumophila Philadelphia-1 is developmentally regulated and a marker of formation of mature intracellular forms.

Legionella pneumophila displays a biphasic developmental cycle in which replicating forms (RFs) differentiate postexponentially into highly infectious, cyst-like mature intracellular forms (MIFs). Using comparative protein profile analyses (MIFs versus RFs), we identified a 20-kDa protein, previously annotated as "Mip-like" protein, that was enriched in MIFs. However, this 20-kDa protein shared no similarity with Mip, a well-characterized peptidyl-prolyl isomerase of L. pneumophila, and for clarity we renamed it MagA (for "MIF-associated gene"). We monitored MagA levels across the growth cycle (in vitro and in vivo) by immunoblotting and established that MagA levels increased postexponentially in vitro (approximately 3-fold) and nearly 10-fold during MIF morphogenesis in HeLa cells. DNA sequence analysis of the magA locus revealed an upstream divergently transcribed gene, msrA, encoding a peptide methionine sulfoxide reductase and a shared promoter region containing direct and indirect repeat sequences as well as -10 hexamers often associated with stationary-phase regulation. While MagA has no known function, it contains a conserved CXXC motif commonly found in members of the thioredoxin reductase family and in AhpD reductases that are associated with alkylhydroperoxide reductase (AhpC), suggesting a possible role in protection from oxidative stress. MIFs from L. pneumophila strain Lp02 containing a magA deletion exhibited differences in Giménez staining, as well as an apparent increase in cytopathology to HeLa cells, but otherwise were unaltered in virulence traits. As demonstrated by this study, MagA appears to be a MIF-specific protein expressed late in intracellular growth that may serve as a useful marker of development.

A 65-kilobase pathogenicity island is unique to Philadelphia-1 strains of Legionella pneumophila.

Nucleotide sequence analysis of an approximately 80-kb genomic region revealed an approximately 65-kb locus that bears hallmarks of a pathogenicity island. This locus includes homologues of a type IV secretion system, mobile genetic elements, and known virulence factors. Comparative studies with other Legionella pneumophila strains and serogroups indicated that this approximately 65-kb locus is unique to L. pneumophila serogroup 1 Philadelphia-1 strains.