Chlamydia trachomatis growth depends on eukaryotic cholesterol esterification and is affected by Acyl-CoA:cholesterol acyltransferase inhibition.

Chlamydia trachomatis is auxotrophic for a variety of essential metabolites. Inhibitors that interrupt host cell catabolism may inhibit chlamydial growth and reveal Chlamydia metabolite requirements. We used the known indoleamine-2,3-dioxygenase (IDO)-inhibitor 4-phenyl imidazole (4-PI) to reverse Interferon (IFN)-γ-induced chlamydial growth inhibition.

Infection with Chlamydia pneumoniae as a cause of coronary heart disease: the hypothesis is still untested.

Review of the possible role of infection in the pathogenesis of heart disease.

Anaphylactic reaction to platelet transfusion as the initial symptom of an undiagnosed systemic mastocytosis: a case report and review of the literature.

Introduction: The association between anaphylactic reactions and systemic mastocytosis is well documented. However, platelet transfusion has not previously been reported as a potential elicitor of anaphylaxis in the context of systemic mastocytosis.

Case Presentation: We describe the clinicopathological findings of a 59-year-old Latin American man who presented to the emergency room with fatigue, leukocytosis, thrombocytopenia and mild hepatosplenomegaly.

Analysis of CPAF mutants: new functions, new questions (the ins and outs of a chlamydial protease).

The role of the chlamydial protease CPAF, previously described as a secreted serine protease processing a wealth of host and chlamydial proteins to promote chlamydial intracellular growth, has recently been questioned by studies from the groups of Tan and Sütterlin, who demonstrated that the reported proteolysis of almost a dozen substrates by CPAF occurred during preparation of cell lysates rather than in intact cells. Valdivia et al. have now compared near-isogenic pairs of CPAF-deficient and secretion-deficient mutants of Chlamydia trachomatis and their wild-type parent.

Chlamydia exploit the mammalian tryptophan-depletion defense strategy as a counter-defensive cue to trigger a survival state of persistence.

We previously proposed that in Chlamydiaceae rapid vegetative growth and a quiescent state of survival (persistence) depend upon alternative protein translational profiles dictated by host tryptophan (Trp) availability. These alternative profiles correspond, respectively, with a set of chlamydial proteins having higher-than-predicted contents of Trp ("Up-Trp" selection), or with another set exhibiting lower-than-predicted contents of Trp ("Down-Trp" selection). A comparative evaluation of Chlamydiaceae proteomes for Trp content has now been extended to a number of other taxon families within the Chlamydiales Order.

Genetic variation in Chlamydia trachomatis and their hosts: impact on disease severity and tissue tropism.

Chlamydia trachomatis infections are a global health problem. This obligate intracellular bacterial pathogen comprises lymphogranuloma venereum (L1-L3), ocular (A-C) and genital (D-K) serovars. Although genetically similar, each serovar group differs in disease severity and tissue tropism through mechanisms that are not well understood.

Challenges and Practices in Building and Implementing Biosafety and Biosecurity Programs to Enable Basic and Translational Research with Select Agents.

Select agent research in the United States must meet federally-mandated biological surety guidelines and rules which are comprised of two main components: biosecurity and biosafety. Biosecurity is the process employed for ensuring biological agents are properly safeguarded against theft, loss, diversion, unauthorized access or use/release. Biosafety is those processes that ensure that operations with such agents are conducted in a safe, secure and reliable manner.

The Chlamydia trachomatis CT149 protein exhibits esterase activity in vitro and catalyzes cholesteryl ester hydrolysis when expressed in HeLa cells.

Chlamydia, like other intracellular bacteria, are auxotrophic for a variety of essential metabolites and obtain cholesterol and fatty acids from their eukaryotic host cell, however not many Chlamydia-specific enzymes have been identified that are involved in lipid metabolism. In silico analysis of one candidate Chlamydia trachomatis enzyme, annotated as a conserved putative hydrolase (CT149), identified two lipase/esterase GXSXG motifs, and a potential cholesterol recognition/interaction amino acid consensus (CRAC) sequence. His-tag purified recombinant CT149 exhibited ester hydrolysis activity in a nitrophenyl acetate-based cell-free assay system.

Host genetics and Chlamydia disease: prediction and validation of disease severity mechanisms.

Genetic mapping studies may provide association between sequence variants and disease susceptibility that can, with further experimental and computational analysis, lead to discovery of causal mechanisms and effective intervention. We have previously demonstrated that polymorphisms in immunity-related GTPases (IRG) confer a significant difference in susceptibility to Chlamydia psittaci infection in BXD recombinant mice. Here we combine genetic mapping and network modeling to identify causal pathways underlying this association.

Platelet satellitism and dual surface immunoglobulin light-chain expression in circulating splenic marginal zone lymphoma cells.

Platelet satellitism is believed to be an in vitro phenomenon induced at room temperature in ethylenediamine tetraacetic acid-anticoagulated blood. Most reports involve neutrophils; involvement with circulating lymphoma cells are exceedingly rare. Normally, mature B cells exhibit allelic exclusion in which a single class of surface immunoglobulin light chains (either κ or λ) is expressed.

Chlamydia psittaci genetic variants differ in virulence by modulation of host immunity.

Background: Psittacosis is a zoonosis caused by Chlamydia psittaci and is characterized by severe pneumonia and systemic infection. We sought to determine the basis of the 1000-fold difference in lethal dose of 2 C. psittaci 6BC strains in mice.

CD28 expressed on malignant plasma cells induces a prosurvival and immunosuppressive microenvironment.

Interactions between the malignant plasma cells of multiple myeloma and stromal cells within the bone marrow microenvironment are essential for myeloma cell survival, mirroring the same dependence of normal bone marrow-resident long-lived plasma cells on specific marrow niches. These interactions directly transduce prosurvival signals to the myeloma cells and also induce niche production of supportive soluble factors. However, despite their central importance, the specific molecular and cellular components involved remain poorly characterized.

Oral and extraoral plasmablastic lymphoma: similarities and differences in clinicopathologic characteristics.

Plasmablastic lymphoma (PBL), initially characterized as an aggressive lymphoma arising in the jaw and oral mucosa in HIV-infected patients, was recently reported to occur with extraoral manifestations, heterogeneous histologic findings, and variable association with immunodeficiency states. We reviewed clinical, morphologic, and immunophenotypic features of 13 cases of PBL to determine whether these different subtypes represent distinct morphologic and clinical entities. Two distinct subtypes of PBL were identified and classified as oral and extraoral PBL.

Summary: The natural history and immunobiology of Chlamydia trachomatis genital infection and implications for Chlamydia control.

In 2008, the US Centers for Disease Control and Prevention held the Chlamydia Immunology and Control Expert Advisory Meeting to foster a dialogue among basic scientists, clinical researchers, and epidemiologists studying genital Chlamydia trachomatis infection. The objectives of the meeting were to determine key questions related to C. trachomatis natural history and immunobiology, with implications for control programs;to review existing data on these key questions; and to delineate research needs to address remaining gaps in knowledge.

Chlamydia trachomatis strains and virulence: rethinking links to infection prevalence and disease severity.

An unanswered question concerning prevalence and disease severity of Chlamydia trachomatis genital infection is whether more prevalent strains or strains more likely to cause serious disease complications are causally associated with specific virulence attributes. The major method for distinguishing chlamydial strains is based on differences in the major outer membrane protein (MOMP). A subset of MOMP serovars (D and E serovars) are easily the most prevalent strains identified worldwide, but MOMP serovar and genovar analyses have not yielded consistent strain-dependent virulence distinctions.

EUS-guided biopsy for the diagnosis and classification of lymphoma.

Background: EUS-guided FNA and Tru-cut biopsy (TCB) is highly accurate in the diagnosis of lymphoma. Subclassification, however, may be difficult in low-grade non-Hodgkin lymphoma and Hodgkin lymphoma.

Objective: To determine the yield of EUS-guided biopsy to classify lymphoma based on the World Health Organization classification of tumors of hematopoietic lymphoid tissues.

High rate and prolonged duration of complete remissions induced by rituximab, methotrexate, doxorubicin, cyclophosphamide, vincristine, ifosfamide, etoposide, cytarabine, and thalidomide (R-MACLO-IVAM-T), a modification of the National Cancer Institute 89-C-41 regimen, in patients with newly diagnosed mantle cell lymphoma.

Novel therapeutic approaches are needed in mantle cell lymphoma (MCL). We conducted a phase II study in MCL testing an intensive regimen, R-MACLO-IVAM-T, a modification of the NCI 89-C-41 protocol. Newly diagnosed patients were treated with rituximab, methotrexate, doxorubicin, cyclophosphamide, and vincristine (cycle 1) followed by rituximab, ifosfamide (and mesna), etoposide, and cytarabine (cycle 2).

Primary bone lymphoma--the University of Miami experience.

Primary bone lymphoma (PBL) is a rare disease. There has been paucity of studies addressing its therapy and prognosis. We retrospectively examined PBL cases seen at the University of Miami from June 2000 to August 2007 to describe our single institution experience and review the literature.

Ocular Adnexal Lymphoma: no evidence for bacterial DNA associated with lymphoma pathogenesis.

Ocular Adnexal Lymphomas (OALs) are the most common tumors of the eye, the majority being extranodal mucosa-associated lymphoid tissue (MALT) lymphomas. Association with Chlamydia psittaci was described in some geographic areas. OAL response to antibiotic therapy was reported in cases not harboring Chlamydia psittaci DNA, suggesting that other bacterial infection might be implicated in the pathogenesis.