High b-value diffusion-weighted imaging: A sensitive method to reveal white matter differences in schizophrenia.

Over the last 10 years, diffusion-weighted imaging (DWI) has become an important tool to investigate white matter (WM) anomalies in schizophrenia. Despite technological improvement and the exponential use of this technique, discrepancies remain and little is known about optimal parameters to apply for diffusion weighting during image acquisition. Specifically, high b-value diffusion-weighted imaging known to be more sensitive to slow diffusion is not widely used, even though subtle myelin alterations as thought to happen in schizophrenia are likely to affect slow-diffusing protons. Schizophrenia patients and healthy controls were scanned with a high b-value (4000s/mm(2)) protocol. Apparent diffusion coefficient (ADC) measures turned out to be very sensitive in detecting differences between schizophrenia patients and healthy volunteers even in a relatively small sample. We speculate that this is related to the sensitivity of high b-value imaging to the slow-diffusing compartment believed to reflect mainly the intra-axonal and myelin bound water pool. We also compared these results to a low b-value imaging experiment performed on the same population in the same scanning session. Even though the acquisition protocols are not strictly comparable, we noticed important differences in sensitivities in the favor of high b-value imaging, warranting further exploration.

Targeting intratumoral B cells with rituximab in addition to CHOP in angioimmunoblastic T-cell lymphoma. A clinicobiological study of the GELA.

Background In angioimmunoblastic T-cell lymphoma, symptoms linked to B-lymphocyte activation are common, and variable numbers of CD20(+) large B-blasts, often infected by Epstein-Barr virus, are found in tumor tissues. We postulated that the disruption of putative B-T interactions and/or depletion of the Epstein-Barr virus reservoir by an anti-CD20 monoclonal antibody (rituximab) could improve the clinical outcome produced by conventional chemotherapy. DESIGN AND METHODS: Twenty-five newly diagnosed patients were treated, in a phase II study, with eight cycles of rituximab + chemotherapy (R-CHOP21). Tumor infiltration, B-blasts and Epstein-Barr virus status in tumor tissue and peripheral blood were fully characterized at diagnosis and were correlated with clinical outcome. RESULTS: A complete response rate of 44% (95% CI, 24% to 65%) was observed. With a median follow-up of 24 months, the 2-year progression-free survival rate was 42% (95% CI, 22% to 61%) and overall survival rate was 62% (95% CI, 40% to 78%). The presence of Epstein-Barr virus DNA in peripheral blood mononuclear cells (14/21 patients) correlated with Epstein-Barr virus score in lymph nodes (P<0.004) and the detection of circulating tumor cells (P=0.0019). Despite peripheral Epstein-Barr virus clearance after treatment, the viral load at diagnosis (>100 copy/μg DNA) was associated with shorter progression-free survival (P=0.06). Conclusions We report here the results of the first clinical trial targeting both the neoplastic T cells and the microenvironment-associated CD20(+) B lymphocytes in angioimmunoblastic T-cell lymphoma, showing no clear benefit of adding rituximab to conventional chemotherapy. A strong relationship, not previously described, between circulating Epstein-Barr virus and circulating tumor cells is highlighted.

New infectious mammary tumor virus superantigen with V beta-specificity identical to staphylococcal enterotoxin B (SEB).

Only few infectious mouse mammary tumor viruses (MMTV) have been characterized which induce a potent superantigen response in vivo. Here we describe the characterization of an MMTV which was isolated from milk of the highly mammary tumor-prone SHN mouse strain. Exposure of newborn mice to milk-borne MMTV (SHN) results in a very slow deletion of V beta 7, 8.1, 8.2 and 8.3 expressing peripheral T cells. Subcutaneous injection of adult mice with this virus induces a rapid and strong stimulation of all four affected V beta-subsets in vivo. Besides the strong T cell effect we observed an early proliferation and activation of the local B cell pool leading to the initial secretion of IgM followed by preferential secretion of IgG2a by day 6. Sequence comparison of the polymorphic C terminus with known open reading frames revealed high homology to the endogenous provirus Mtv-RCS. This is the first report of a virus having a complete overlap in V beta-specificity with a bacterial superantigen stimulating as many as 35% of the whole CD4+ T cell repertoire including V beta 8.2.

TNF deficiency fails to protect BAFF transgenic mice against autoimmunity and reveals a predisposition to B cell lymphoma.

TNF is well characterized as a mediator of inflammatory responses. TNF also facilitates organization of secondary lymphoid organs, particularly B cell follicles and germinal centers, a hallmark of T-dependent Ab responses. TNF also mediates defense against tumors. We examined the role of TNF in the development of inflammatory autoimmune disorders resembling systemic lupus erythematosus and Sjögren's syndrome induced by excess B cell-activating factor belonging to the TNF family (BAFF), by generating BAFF-transgenic (Tg) mice lacking TNF. TNF(-/-) BAFF-Tg mice resembled TNF(-/-) mice, in that they lacked B cell follicles, follicular dendritic cells, and germinal centers, and have impaired responses to T-dependent Ags. Nevertheless, TNF(-/-) BAFF-Tg mice developed autoimmune disorders similar to that of BAFF-Tg mice. Disease in TNF(-/-) BAFF-Tg mice correlates with the expansion of transitional type 2 and marginal zone B cell populations and enhanced T-independent immune responses. TNF deficiency in BAFF-Tg mice also led to a surprisingly high incidence of B cell lymphomas (&gt;35%), which most likely resulted from the combined effects of BAFF promotion of neoplastic B cell survival, coupled with lack of protective antitumor defense by TNF. Thus, TNF appears to be dispensable for BAFF-mediated autoimmune disorders and may, in fact, counter any proneoplastic effects of high levels of BAFF in diseases such as Sjögren's syndrome, systemic lupus erythematosus, and rheumatoid arthritis.

The Cul3-KLHL21 E3 ubiquitin ligase targets aurora B to midzone microtubules in anaphase and is required for cytokinesis.

Cul3 (Cullin3)-based E3 ubiquitin ligases recently emerged as critical regulators of mitosis. In this study, we identify two mammalian BTB (Bric-a-brac-Tramtrack-Broad complex)-Kelch proteins, KLHL21 and KLHL22, that interact with Cul3 and are required for efficient chromosome alignment. Interestingly, KLHL21 but not KLHL22 is necessary for cytokinesis and regulates translocation of the chromosomal passenger complex (CPC) from chromosomes to the spindle midzone in anaphase, similar to the previously described BTB-Kelch proteins KLHL9 and KLHL13. KLHL21 directly binds to aurora B and mediates ubiquitination of aurora B in vitro. In contrast to KLHL9 and KLHL13, KLHL21 localizes to midzone microtubules in anaphase and recruits aurora B and Cul3 to this region. Together, our results suggest that different Cul3 adaptors nonredundantly regulate aurora B during mitosis, possibly by ubiquitinating different pools of aurora B at distinct subcellular localizations.

Molecular phylogenetics of soricid shrews (Mammalia) based on mitochondrial cytochrome b gene sequences: with special reference to the Soricinae

Molecular phylogeny of soricid shrews (Soricidae, Eulipotyphla, Mammalia) based on 1140 bp mitochondrial cytochrome b gene (cytb) sequences was inferred by the maximum likelihood (ML) method. All 13 genera of extant Soricinae and two genera of Crocidurinae were included in the analyses. Anourosorex was phylogenetically distant from the main groupings within Soricinae and Crocidurinae in the ML tree. Thus, it could not be determined to which subfamily Anourosorex should be assigned: Soricinae, Crocidurinae or a new subfamily. Soricinae (excluding Anourosorex) should be divided into four tribes: Neomyini, Notiosoricini, Soricini and Blarinini. However, monophyly of Blarinini was not robust in the present data set. Also, branching orders among tribes of Soricinae and those among genera of Neomyini could not be determined because of insufficient phylogenetic information of the cytb sequences. For water shrews of Neomyini (Chimarrogale, Nectogale and Neomys), monophyly of Neomys and the Chimarrogale-Nectogale group could not be verified, which implies the possibility of multiple origins for the semi-aquatic mode of living among taxa within Neomyini. Episoriculus may contain several separate genera. Blarinella was included in Blarinini not Soricini, based on the cytb sequences, but the confidence level was rather low; hence more phylogenetic information is needed to determine its phylogenetic position. Furthermore, some specific problems of taxonomy of soricid shrews were clarified, for example phylogeny of local populations of Notiosorex crawfordi, Chimarrogale himalayica and Crocidura attenuata.

High b-value Diffusion-weighted Imaging: A Sensitive Method to Reveal White Matter Changes in Schizophrenia

Background: b-value is the parameter characterizing the intensity of the diffusion weighting during image acquisition. Data acquisition is usually performed with low b value (b~1000 s/mm2). Evidence shows that high b-values (b>2000 s/mm2) are more sensitive to the slow diffusion compartment (SDC) and maybe more sensitive in detecting white matter (WM) anomalies in schizophrenia.Methods: 12 male patients with schizophrenia (mean age 35 +/-3 years) and 16 healthy male controls matched for age were scanned with a low b-value (1000 s/mm2) and a high b-value (4000 s/mm2) protocol. Apparent diffusion coefficient (ADC) is a measure of the average diffusion distance of water molecules per time unit (mm2/s). ADC maps were generated for all individuals. 8 region of interests (frontal and parietal region bilaterally, centrum semi-ovale bilaterally and anterior and posterior corpus callosum) were manually traced blind to diagnosis.Results: ADC measures acquired with high b-value imaging were more sensitive in detecting differences between schizophrenia patients and healthy controls than low b-value imaging with a gain in significance by a factor of 20- 100 times despite the lower image Signal-to-noise ratio (SNR). Increased ADC was identified in patient's WM (p=0.00015) with major contributions from left and right centrum semi-ovale and to a lesser extent right parietal region.Conclusions: Our results may be related to the sensitivity of high b-value imaging to the SDC believed to reflect mainly the intra-axonal and myelin bound water pool. High b-value imaging might be more sensitive and specific to WM anomalies in schizophrenia than low b-value imaging

NFκB activation by modified vaccinia virus as a novel strategy to enhance neutrophil migration and HIV-specific T-cell responses.

Neutrophils are antigen-transporting cells that generate vaccinia virus (VACV)-specific T-cell responses, yet how VACV modulates neutrophil recruitment and its significance in the immune response are unknown. We generated an attenuated VACV strain that expresses HIV-1 clade C antigens but lacks three specific viral genes (A52R, K7R, and B15R). We found that these genes act together to inhibit the NFκB signaling pathway. Triple ablation in modified virus restored NFκB function in macrophages. After virus infection of mice, NFκB pathway activation led to expression of several cytokines/chemokines that increased the migration of neutrophil populations (Nα and Nβ) to the infection site. Nβ cells displayed features of antigen-presenting cells and activated virus-specific CD8 T cells. Enhanced neutrophil trafficking to the infection site correlated with an increased T-cell response to HIV vector-delivered antigens. These results identify a mechanism for poxvirus-induced immune response and alternatives for vaccine vector design.

Extrafollicular plasmablast B cells play a key role in carrying retroviral infection to peripheral organs.

B cells can either differentiate in germinal centers or in extrafollicular compartments of secondary lymphoid organs. Here we show the migration properties of B cells after differentiation in murine peripheral lymph node infected with mouse mammary tumor virus. Naive B cells become activated, infected, and carry integrated retroviral DNA sequences. After production of a retroviral superantigen, the infected B cells receive cognate T cell help and differentiate along the two main differentiation pathways analogous to classical Ag responses. The extrafollicular differentiation peaks on day 6 of mouse mammary tumor virus infection, and the follicular one becomes detectable after day 10. B cells participating in this immune response carry a retroviral DNA marker that can be detected by using semiquantitative PCR. We determined the migration patterns of B cells having taken part in the T cell-B cell interaction from the draining lymph node to different tissues. Waves of immigration and retention of infected cells in secondary lymphoid organs, mammary gland, salivary gland, skin, lung, and liver were observed correlating with the two peaks of B cell differentiation in the draining lymph node. Other organs revealed immigration of infected cells at later time points. The migration properties were correlated with a strong up-regulation of alpha(4)beta(1) integrin expression. These results show the migration properties of B cells during an immune response and demonstrate that a large proportion of extrafolliculary differentiating plasmablasts can escape local cell death and carry the retroviral infection to peripheral organs.

09028-014 Tributary B to Fourmile Creek Final Report

The city of Ankeny is submitting this WIRB application for development of green urban stormwater practices on city and private property in the Fourmile Creek watershed. The stormwater project proposed includes stream restoration of the SE Tributary to Fourmile Creek (Tributary B), including weirs, bank shaping, toe protection, trees, and native plantings. The project also includes the creation of a native buffer along the stream channel in the city’s Summerbrook Park, installing four native planting beds, installing a pervious surface trail, installing a series of rain gardens/biorentention cells, and installing educational signage. Polk County Soil and Water Conservation District has committed $17,000 towards the native buffer and rain garden/biorentention cell. The city of Ankeny was also awarded a $100,000 I-JOBS grant from IDNR to complete the stormwater retrofit practices. The largest component of this project is public education. Our vision for this project is to take the entire 281 acre watershed and address it as a whole. We want to make a collaborative watershed that not only addresses the water entering the stream channel through adjacent properties, but takes each individual parcel within the watershed and strives to reduce contributions to the stormwater system. The stormwater issues of concern for Tributary B include stormwater volume, sediment, and nutrients. The stream restoration, best management practices (BMP) at Summerbrook Park, and BMPs on private property should help decrease the volume of stormwater and reduce the amount of sediment and nutrients that enter Tributary B and ultimately Fourmile Creek.

Inflammasome-activated caspase 7 cleaves PARP1 to enhance the expression of a subset of NF-κB target genes.

Caspase 1 is part of the inflammasome, which is assembled upon pathogen recognition, while caspases 3 and/or 7 are mediators of apoptotic and nonapoptotic functions. PARP1 cleavage is a hallmark of apoptosis yet not essential, suggesting it has another physiological role. Here we show that after LPS stimulation, caspase 7 is activated by caspase 1, translocates to the nucleus, and cleaves PARP1 at the promoters of a subset of NF-κB target genes negatively regulated by PARP1. Mutating the PARP1 cleavage site D214 renders PARP1 uncleavable and inhibits PARP1 release from chromatin and chromatin decondensation, thereby restraining the expression of cleavage-dependent NF-κB target genes. These findings propose an apoptosis-independent regulatory role for caspase 7-mediated PARP1 cleavage in proinflammatory gene expression and provide insight into inflammasome signaling.

Susceptibility of clinical isolates of Leishmania aethiopica to miltefosine, paromomycin, amphotericin B and sodium stibogluconate using amastigote-macrophage in vitro model.

Cutaneous Leishmaniasis (CL) caused by Leishmania aethiopica is a public health and social problem with a sequel of severe and mutilating skin lesions. It is manifested in three forms: localized CL (LCL), mucosal CL (MCL) and diffuse CL (DCL). Unresponsiveness to sodium stibogluconate (Sb(V)) is common in Ethiopian CL patients. Using the amastigote-macrophage in vitro model the susceptibility of 24 clinical isolates of L. aethiopica derived from untreated patients was investigated. Eight strains of LCL, 9 of MCL, and 7 of DCL patients together with a reference strain (MHOM/ET/82/117/82) were tested against four antileishmanial drugs: amphotericin B, miltefosine, Sb(V) and paromomycin. In the same order of drugs, IC(50) (μg/ml±SD) values for the 24 strains tested were 0.16±0.18, 5.88±4.79, 10.23±8.12, and 13.63±18.74. The susceptibility threshold of isolates originating from the 3 categories of patients to all 4 drugs was not different (p>0.05). Maximal efficacy was superior for miltefosine across all the strains. Further susceptibility test could validate miltefosine as a potential alternative drug in cases of sodium stibogluconate treatment failure in CL patients.