BACKGROUNDPoorly differentiated thyroid carcinomas (PDTC) occupy an intermediate position at the prognostic level on the spectrum of thyroid carcinoma progression. However, their histologic definition is controversial. The objective of the current study was to assess the prognostic significance of PDTC defined on the basis of mitosis and necrosis and search for prognostic markers within this group of tumors that are predictive of overall survival (OS) and progression‐free survival (PFS).METHODSPDTC was defined as thyroid carcinoma with follicular cell differentiation at the histologic and/or immunohistochemical levels and displaying tumor necrosis and/or ≥ 5 mitoses per 10 high‐power fields (×400). Retrospective chart review and microscopic examination identified 58 patients with primary tumors meeting the above criteria and seen at the Memorial Sloan‐Kettering Cancer Center between 1992 and 2004. These 58 patients were analyzed for various histologic, clinical, and imaging parameters. Each parameter was correlated with OS and PFS.RESULTSOf the 58 patients studied, 22 (38%) patients died of disease with a 5‐year OS rate of 60%. Forty‐three of the 58 patients (74%) developed disease recurrence or disease progression, with a 5‐year PFS rate of 25%. The median follow‐up for the entire patient population was 42.6 months (range, 4–205 mos). A tumor size > 4 cm was found to be correlated with a decreased PFS time (P < 0.001). Those tumors with a capsule demonstrated a significantly improved OS compared with unencapsulated tumors (P = 0.001). The extent of capsular invasion was found to be a significant adverse factor for PFS (P = 0.05). The presence of extrathyroid extension into perithyroid soft tissue was found to be correlated with a decreased OS (P = 0.001) and PFS (P = 0.004). Of 27 patients with distant metastasis, 19 (70%) had concentrated radioactive iodine (RAI) at their metastatic sites. On multivariate analysis, extrathyroid extension and tumor size emerged as the only significant variables in predicting PFS (P = 0.04 and P = 0.01, respectively) whereas extrathyroid extension was found to be the sole independent prognostic factor for OS (P = 0.01). Growth pattern and cell type did not appear to influence outcome.CONCLUSIONSPDTC defined on the basis of mitosis and necrosis constitutes a group of tumors that is more aggressive and homogeneous than PDTC defined by growth pattern. Within this group of patients, microstaging (tumor size, the extent of capsular invasion, and, especially, extrathyroid extension), and not growth pattern or cell type, is able to stratify patients into different prognostic categories. RAI uptake occurs in a significant number of patients with PDTC. Cancer 2006. © 2006 American Cancer Society.

Background:We studied ribosome and nucleoid distribution in Escherichia coli under growth and quiescence. Results: Spatially segregated ribosomes and nucleoids show drastically altered distribution in stationary phase or when treated with drugs affecting translation, transcription, nucleoid-topology, or cytoskeleton. Ribosome inheritance in daughter cells is frequently unequal. Conclusion: Cellular growth processes modulate ribosome and nucleoid distribution. Significance: This provides insight into subcellular organization of molecular machines.

Using Caenorhabditis elegans as an infection host model for Vibrio cholerae predator interactions, we discovered a bacterial cytotoxin, MakA, whose function as a virulence factor relies on secretion via the flagellum channel in a proton motive force-dependent manner. The MakA protein is expressed from the polycistronic makDCBA (motility-associated killing factor) operon. Bacteria expressing makDCBA induced dramatic changes in intestinal morphology leading to a defecation defect, starvation and death in C. elegans. The Mak proteins also promoted V. cholerae colonization of the zebrafish gut causing lethal infection. A structural model of purified MakA at 1.9 Å resolution indicated similarities to members of a superfamily of bacterial toxins with unknown biological roles. Our findings reveal an unrecognized role for V. cholerae flagella in cytotoxin export that may contribute both to environmental spread of the bacteria by promoting survival and proliferation in encounters with predators, and to pathophysiological effects during infections.

Mycobacteria owe their success as pathogens to their ability to persist for long periods within host cells in asymptomatic, latent forms before they opportunistically switch to the virulent state. The molecular mechanisms underlying the transition into dormancy and emergence from it are not clear. Here we show that old cultures of Mycobacterium marinum contained spores that, upon exposure to fresh medium, germinated into vegetative cells and reappeared again in stationary phase via endospore formation. They showed many of the usual characteristics of well-known endospores. Homologues of well-known sporulation genes of Bacillus subtilis and Streptomyces coelicolor were detected in mycobacteria genomes, some of which were verified to be transcribed during appropriate life-cycle stages. We also provide data indicating that it is likely that old Mycobacterium bovis bacillus Calmette-Gué rin cultures form spores. Together, our data show sporulation as a lifestyle adapted by mycobacteria under stress and tempt us to suggest this as a possible mechanism for dormancy and/or persistent infection. If so, this might lead to new prophylactic strategies.Mycobacterium marinum ͉ cell division ͉ DNA replication ͉ cell cycle ͉ endosporulation

TCV without ETE is biologically a more aggressive tumor than classical PTC without ETE independent of age, gender, and tumor size.