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The fibrotic encapsulation of implants involves the mechanical activation of myofibroblasts and of pro-fibrotic transforming growth factor beta 1 (TGF-β1). Here, we show that both softening of the implant surfaces and inhibition of the activation of TGF-β1 reduce the fibrotic encapsulation of subcutaneous silicone implants in mice. Conventionally stiff silicones (elastic modulus, ~2 MPa) coated with a soft silicone layer (elastic modulus, ~2 kPa) reduced collagen deposition as well as myofibroblast activation without affecting the numbers of macrophages and their polarization states. Instead, fibroblasts around stiff implants exhibited enhanced intracellular stress, increased the recruitment of αv and β1 integrins, and activated TGF-β1 signalling. In vitro, the recruitment of αv integrin to focal adhesions and the activation of β1 integrin and of TGF-β were higher in myofibroblasts grown on latency-associated peptide (LAP)-coated stiff silicones than on soft silicones. Antagonizing αv integrin binding to LAP through the small-molecule inhibitor CWHM-12 suppressed active TGF-β signalling, myofibroblast activation and the fibrotic encapsulation of stiff subcutaneous implants in mice. The fibrotic encapsulation of subcutaneous silicone implants in mice can be suppressed by softening the implant surface or inhibiting the integrin-mediated activation of transforming growth factor beta 1.

Summary Pulmonary tuberculosis (TB) is an airborne disease caused by the intracellular bacterial pathogen Mycobacterium tuberculosis (Mtb). Alveolar epithelial cells and macrophages are the first point of contact for Mtb in the respiratory tract. However, the mechanisms of mycobacterial attachment to, and internalization by, nonprofessional phagocytes, such as epithelial cells, remain incompletely understood. We identified syndecan 4 (Sdc4) as mycobacterial attachment receptor on alveolar epithelial cells. Sdc4 mRNA expression was increased in human and mouse alveolar epithelial cells after mycobacterial infection. Sdc4 knockdown in alveolar epithelial cells or blocking with anti-Sdc4 antibody reduced mycobacterial attachment and internalization. At the molecular level, interactions between epithelial cells and mycobacteria involved host Sdc and the mycobacterial heparin-binding hemagglutinin adhesin. In vivo, Sdc1/Sdc4 double-knockout mice were more resistant to Mtb colonization of the lung. Our work reveals a role for distinct Sdcs in promoting mycobacterial entry into alveolar epithelial cells with impact on outcome of TB disease.

Dysregulated secretion and extracellular activation of TGF-β1 stimulates myofibroblasts to accumulate disordered and stiff extracellular matrix (ECM) leading to fibrosis. Fibronectin immobilizes latent TGF-β-binding protein-1 (LTBP-1) and thus stores TGF-β1 in the ECM. Because the ED-A fibronectin splice variant is prominently expressed during fibrosis and supports myofibroblast activation, we investigated whether ED-A promotes LTBP-1-fibronectin interactions. Using stiffness-tuneable substrates for human dermal fibroblast cultures, we showed that high ECM stiffness promotes expression and colocalization of LTBP-1 and ED-A-containing fibronectin. When rescuing fibronectin-depleted fibroblasts with specific fibronectin splice variants, LTBP-1 bound more efficiently to ED-A-containing fibronectin than to ED-B-containing fibronectin and fibronectin lacking splice domains. Function blocking of the ED-A domain using antibodies and competitive peptides resulted in reduced LTBP-1 binding to ED-A-containing fibronectin, reduced LTBP-1 incorporation into the fibroblast ECM and reduced TGF-β1 activation. Similar results were obtained by blocking the heparin-binding stretch FNIII12-13-14 (HepII), adjacent to the ED-A domain in fibronectin. Collectively, our results suggest that the ED-A domain enhances association of the latent TGF-β1 by promoting weak direct binding to LTBP-1 and by enhancing heparin-mediated protein interactions through HepII in fibronectin.

Spread of bacteria via the bloodstream to vital organs causes most mortality due to bacterial infection. To exit the bloodstream and enter these organs, bacteria must be able to resist the forces generated by flowing blood so that they can adhere to the endothelial cells lining blood vessels without being washed away. This process is not yet understood for most disease-causing bacteria. Here, we show that the Lyme disease pathogen Borrelia burgdorferi exploits an abundant constituent of blood, plasma fibronectin, to form endothelial interactions that become stronger as forces due to blood-flow increase. The ability to recruit this highly conserved molecule may also be important for the vascular interaction mechanisms of other pathogens.

Bacterial dissemination via the cardiovascular system is the most common cause of infection mortality. A key step in dissemination is bacterial interaction with endothelia lining blood vessels, which is physically challenging because of the shear stress generated by blood flow. Association of host cells such as leukocytes and platelets with endothelia under vascular shear stress requires mechanically specialized interaction mechanisms, including force-strengthened catch bonds. However, the biomechanical mechanisms supporting vascular interactions of most bacterial pathogens are undefined. Fibronectin (Fn), a ubiquitous host molecule targeted by many pathogens, promotes vascular interactions of the Lyme disease spirochete Borrelia burgdorferi. Here, we investigated how B. burgdorferi exploits Fn to interact with endothelia under physiological shear stress, using recently developed live cell imaging and particle-tracking methods for studying bacterial–endothelial interaction biomechanics. We found that B. burgdorferi does not primarily target insoluble matrix Fn deposited on endothelial surfaces but, instead, recruits and induces polymerization of soluble plasma Fn (pFn), an abundant protein in blood plasma that is normally soluble and nonadhesive. Under physiological shear stress, caps of polymerized pFn at bacterial poles formed part of mechanically loaded adhesion complexes, and pFn strengthened and stabilized interactions by a catch-bond mechanism. These results show that B. burgdorferi can transform a ubiquitous but normally nonadhesive blood constituent to increase the efficiency, strength, and stability of bacterial interactions with vascular surfaces. Similar mechanisms may promote dissemination of other Fn-binding pathogens.

Aims Pathological tissue remodelling by myofibroblast contraction is a hallmark of cardiac fibrosis. Myofibroblasts differentiate from cardiac fibroblasts under the action of transforming growth factor-β1 (TGF-β1), which is secreted into the extracellular matrix as a large latent complex. Integrin-mediated traction forces activate TGF-β1 by inducing a conformational change in the latent complex. The mesenchymal integrins αvβ5 and αvβ3 are expressed in the heart, but their role in the activation of TGF-β1 remains elusive. Here, we test whether targeting αvβ5 and αvβ3 integrins reduces latent TGF-β1 activation by cardiac fibroblasts with the goal to prevent the formation of α-smooth muscle actin (α-SMA)-expressing cardiac myofibroblasts and their contribution to fibrosis. Methods and results Using a porcine model of induced right ventricular fibrosis and pro-fibrotic culture conditions, we show that integrins αvβ5 and αvβ3 are up-regulated in myofibroblast-enriched fibrotic lesions and differentiated cultured human cardiac myofibroblasts. Both integrins autonomously contribute to latent TGF-β1 activation and myofibroblast differentiation, as demonstrated by function-blocking peptides and antibodies. Acute blocking of both integrins leads to significantly reduced TGF-β1 activation by cardiac fibroblast contraction and loss of α-SMA expression, which is restored by adding active TGF-β1. Manipulating integrin protein levels in overexpression and shRNA experiments reveals that both integrins can compensate for each other with respect to TGF-β1 activation and induction of α-SMA expression. Conclusions Integrins αvβ5 and αvβ3 both control myofibroblast differentiation by activating latent TGF-β1. Pharmacological targeting of mesenchymal integrins is a possible strategy to selectively block TGF-β1 activation by cardiac myofibroblasts and progression of fibrosis in the heart.

Introduction: Selection of patients for endovascular therapy (EVT) may depend on the hospital providing first line assessment. In our collaborative stroke network, we aimed to compare clinical characteristics and outcomes in ischemic stroke patients undergoing EVT who were transferred from telestroke hospitals following teleconsultation and in those transferred from hospitals providing on-site neurology service. Methods: We analyzed prospectively collected data from consecutive ischemic stroke patients who underwent emergent EVT at our comprehensive stroke center (01/2010 to 12/2014) after acute transfer from either telestroke hospitals or non-telestroke hospitals with on-site neurology service. We compared baseline characteristics, onset-to-EVT time, symptomatic intracranial hemorrhage (sICH), favorable functional outcome (mRS 0-2) at discharge and in-hospital mortality. Results: Among 133 transferred patients who underwent emergent EVT: median age 67 years (IQR, 15); 56% men; median NIHSS score 17 (21); 52% had anterior and 48% posterior circulation stroke. Sixty-five patients (49%) were transferred from telestroke and 68 (51%) from non-telestroke hospitals. Telestroke patients were less severely affected (median NIHSS scores: 15 [7] vs. 22 [20]; p=.0005) and more likely to have anterior circulation stroke (69% vs. 35%; p Conclusions: Patients transferred from telestroke hospitals were twice as often treated for anterior circulation stroke than those from non-telestroke neurological hospitals within our stroke network. This might be explained by more conservative selection of patients potentially amenable for EVT in hospitals harboring on-site neurology service but no EVT-capability. As our data was acquired prior to evidence from the positive EVT trials, further research is warranted to elaborate these findings.

Background: The diagnostic value of cerebrospinal fluid (CSF) analysis in identification of stroke etiology in patients with juvenile stroke remains not well studied. We sought to determine the frequency and underlying causes of pathological CSF-findings in juvenile stroke patients who underwent CSF-analysis as part of their diagnostic work-up. Methods: We retrospectively abstracted data from consecutive (01/2008 to 12/2015) patients aged 18 to 45 years with acute ischemic stroke or transient ischemic attack. Routine work-up included MRI with dissection-sensitive sequences, Holter-ECG, transthoracic and transesophageal echocardiography, duplex ultrasound of extra- and intracranial arteries and screening for coagulopathies, vasculitis and Fabry disease. CSF-analysis was routinely performed in patients with hitherto cryptogenic stroke. We assessed frequency and causes of pathological CSF-findings including microbiological and virological abnormalities, and their impact on the choice of specific therapy for secondary stroke prevention. Results: Among 379 juvenile patients with acute ischemic stroke or transient ischemic attack, CSF analysis was performed in 201 patients (53%). Of these, 26 patients (13%) had CSF pleocytosis (leucocyte cell count ≥5 Mpt/l). CSF-pleocytosis was rated false positive (e.g. traumatic lumbar puncture, reactive pleocytosis due to acute stroke) after exclusion of specific conditions in 23 of these patients. Only 2 patients with CSF-pleocytosis (1% of patients who underwent CSF analysis) had specific CSF-findings (Lyme disease and neurosyphilis with consecutive cerebral vasculitis) as a cause of stroke and subsequent impact on secondary stroke prevention therapy. One patient had serological evidence of chronic infection with Mycoplasma pneumoniae that was rated as a contributing factor to stroke pathophysiology. Conclusions: The diagnostic yield of routine CSF-analysis in juvenile stroke patients was remarkably low in our study. Our data suggest that CSF-analysis should only be performed if further findings raise the suspicion of cerebral vasculitis.

A lack of host-derived SPARC promotes disease progression in an intraperitoneal (IP) ID8 mouse model of epithelial ovarian cancer (EOC). Since orthotopic injection (OT) of ID8 cells better recapitulates high-grade serous cancer, we examined the impact of host-derived SPARC following OT injection. Sparc−/− and wild-type (WT) mice were injected with ID8 cells either OT or IP and tumors were analyzed at the moribund stage. Sparc−/− mice had reduced survival and fewer well-defined abdominal lesions compared with WT controls after IP injection, whereas no differences were observed in survival or abdominal lesions between Sparc−/− and WT mice after OT injection. No differences in mass or collagen content were observed in ovarian tumors between OT-injected Sparc−/− and WT mice. The abdominal wall of the IP-injected Sparc−/− mice exhibited immature and less abundant collagen fibrils compared with WT mice both in injected and non-injected controls. In contrast to human EOC, SPARC was expressed by the tumor cells but was absent in reactive stroma of WT mice. Exposure to the ovarian microenvironment through OT injections alters the metastatic behaviour of ID8 cells, which is not affected by the absence of host-derived SPARC.

Nematocysts containing coiled polar filaments are a distinguishing feature of members of the phylum Cnidaria. As a first step to characterizing the molecular structure of polar filaments, a polyclonal antiserum was raised in rabbits against a cyanogen bromide–resistant protein extract of mature cysts containing spores of Myxobolus pendula. The antiserum reacted only with proteins associated with extruded polar filaments. Western blot and whole-mount immunohistochemical analyses indicated a conservation of polar filament epitopes between M. pendula and 2 related cnidarians, i.e., the anthozoan, Nematostella vectensis, and the hydrozoan, Hydra vulgaris. This conservation of polar filament epitopes lends further support to a shared affinity between Myxozoa and cnidarians.

Introduction: Elevated arterial blood pressure (BP) increases the risk of intracerebral hemorrhage after intravenous (IV) thrombolysis with tPA in acute ischemic stroke (AIS). While arterial BP is usually monitored using intermittent oscillometric measurements with an upper arm cuff, the vascular unloading technique (VUT) provides non-invasive continuous BP monitoring with a finger cuff. Hypothesis: We hypothesized that VUT monitoring is feasible in AIS patients receiving IV tPA, is comparable to the standard technique, and allows detection of BP peaks that might be missed in oscillometric BP monitoring. Methods: We performed an interim analysis of an ongoing prospective method comparison study. AIS patients were simultaneously monitored over 24 h following IV tPA bolus using VUT and contralateral oscillometric BP assessment every 30 min. Results: We present interim data from 15 out of 24 AIS (4 m, 11 f; aged 72.5±14.9 y, mean±SD) receiving IV tPA. Nominal significance level was set to 0.029 in accordance with Pocock’s rule. Missing data were less than 5% for both techniques. There was a positive correlation between VUT and oscillometric BP assessment (Pearson’s correlation coefficient r=0.91, p180 or diastolic BP>110 mmHg) were detected by VUT monitoring (at least one episode≥5 min) in 12 patients, and by oscillometric BP assessment (≥one time point of measurement) in 7 patients (p Conclusions: Our interim data suggest that VUT-based BP monitoring is feasible in AIS patients receiving IV tPA, and might be more sensitive than intermittent oscillometric BP assessment in detecting potentially harmful blood pressure peaks. Figure 1: Bland Altman plot

Dipetarudin is a potent direct thrombin inhibitor that was genetically engineered as a chimera between dipetalogastin II and hirudin. Dipetarudin was initially cloned and purified from Escherichia coli, but with a very low yield of about 0.3 mg/l of culture medium. In this study, we report the production of dipetarudin in the methylotrophic yeast Pichia pastoris using pPIC9 vector. The His+ transformants were screened for the best expression performances by prolongation of the ecarin clotting time. An optimal dipetarudin’s expression was reached by addition of methanol in culture medium to a final concentration of 0.5%, every 8 h during 4 days. Secreted dipetarudin was purified essentially using a two-step purification scheme: anion exchange chromatography in a Resource Q column, followed by C18-reversed phase HPLC. About 150 mg purified dipetarudin was obtained from 1 l culture supernatant. This yield is 500-fold higher than the yield obtained with the E. coli system. The molecular mass of dipetarudin calculated by MALDI-TOF (7450 Da) was in agreement with the mass calculated by the amino acid composition (7454 Da), indicating correct processing of the signal sequence. The Ki value of dipetarudin was 399 ± 83 fM, which is in agreement with that calculated for the inhibitor isolated from E. coli. This efficient and cost-effective expression system facilitates large-scale production and purification of dipetarudin for further structural, functional and pharmacological investigations.

Expansion on stiff culture substrates activates pro-fibrotic cell programs that are retained by mechanical memory. Here, we show that priming on physiologically soft silicone substrates suppresses fibrogenesis and desensitizes mesenchymal stem cells (MSCs) against subsequent mechanical activation in vitro and in vivo, and identify the microRNA miR-21 as a long-term memory keeper of the fibrogenic program in MSCs. During stiff priming, miR-21 levels were gradually increased by continued regulation through the acutely mechanosensitive myocardin-related transcription factor-A (MRTF-A/MLK-1) and remained high over 2 weeks after removal of the mechanical stimulus. Knocking down miR-21 once by the end of the stiff-priming period was sufficient to erase the mechanical memory and sensitize MSCs to subsequent exposure to soft substrates. Soft priming and erasing mechanical memory following cell culture expansion protects MSCs from fibrogenesis in the host wound environment and increases the chances for success of MSC therapy in tissue-repair applications.

Spores of Myxobolus pendula develop within the cores of complex cysts on the gill arch of creek chub Semotilus atromaculatus. Adjacent to, and surrounding, the spores are concentric layers of stratified interdigitating cells, whose nature was examined by transmission electron microscopy and by immunohistochemical and molecular biological techniques. In situ hybridization data using parasite-derived ribosomal DNA as a probe indicate that infection leads to the encapsulation of developing plasmodia by host immune cells that form an epithelioid granuloma. Epithelioid cell-cell adhesion is effected by desmosomes anchored intracellularly to cytokeratin intermediate filaments. High levels of alkaline phosphatase activity are associated with regions of cellular interdigitation. The granuloma may serve to limit the spread of the parasite to surrounding tissues but does not appear to inhibit diffusion of oxygen and nutrients to the developing spores.

L'organisation de la structure musculaire de l'intestin moyen des femelles de l'espece ornithophile Simulium rugglesi et de l'espece mammalophile Simulium venustum a ete examinee par microscopie confocale. De plus, l'association entre les muscles longitudinaux et circulaires de S. rugglesi alimentes a ete determinee par microscopie electronique a transmission. Les muscles longitudinaux et circulaires des deux especes sont places en arrangement orthogonal pour former une structure en grille. Chez S. rugglesi, le nombre de muscles longitudinaux a ete estime a 181 et le nombre de muscles circulaires, a 90, alors que, chez S. venustum, il y a environ 156 muscles longitudinaux et 69 muscles circulaires. Les muscles longitudinaux ont un espacement inegal et ils sont arranges en paquets de faisceaux paralleles. La bifurcation des muscles longitudinaux se produit au hasard le long de l'intestin moyen chez S. rugglesi, mais chez S. venustum, elle se situe anterieurement et posterieurement a la partie la plus renflee de la region posterieure de l'intestin moyen. Les muscles circulaires affichent moins de variation dans l'espacement de leurs faisceaux et leur embranchement est plus regulier. Les faisceaux de muscles circulaires partagent des fibres avec les faisceaux voisins, ce qui les rattache tout le long de l'intestin moyen. L'observation d'intestins moyens de S. rugglesi au microscope electronique a permis de constater l'existence de connections entre les muscles longitudinaux et les muscles circulaires. La comparaison de ces resultats avec ceux obtenus chez les moustiques revele que l'organisation et la structure de la musculature de l'intestin moyen sont semblables chez les deux groupes.

A mild strain induced by matrix remodeling mechanically primes latent TGF-β1 for its subsequent activation and release in response to contractile forces., Integrin-mediated force application induces a conformational change in latent TGF-β1 that leads to the release of the active form of the growth factor from the extracellular matrix (ECM). Mechanical activation of TGF-β1 is currently understood as an acute process that depends on the contractile force of cells. However, we show that ECM remodeling, preceding the activation step, mechanically primes latent TGF-β1 akin to loading a mechanical spring. Cell-based assays and unique strain devices were used to produce a cell-derived ECM of controlled organization and prestrain. Mechanically conditioned ECM served as a substrate to measure the efficacy of TGF-β1 activation after cell contraction or direct force application using magnetic microbeads. The release of active TGF-β1 was always higher from prestrained ECM as compared with unorganized and/or relaxed ECM. The finding that ECM prestrain regulates the bioavailability of TGF-β1 is important to understand the context of diseases that involve excessive ECM remodeling, such as fibrosis or cancer.

Fibroblasts differentiate into the highly synthetic and contractile myofibroblast phenotype when exposed to substrates with an elastic modulus corresponding to pathologically stiff fibrotic tissue. Cellular responses to changes in substrate stiffness are typically analyzed after hours or days, which does not enable the monitoring of myofibroblast persistence, a hallmark of fibrosis. To determine long-lasting effects on the fibrotic behavior of lung fibroblasts, we followed a novel approach of explanting and repeatedly passaging fibroblasts on silicone substrates with stiffness representing various states of lung health. Fibrotic activity was determined by assaying for myofibroblast proliferation, cell contractility, expression of α-smooth muscle actin, extracellular matrix and active TGFβ1. As predicted, myofibroblast activity was low on healthy soft substrates and increased with increasing substrate stiffness. However, explanting and mechanically priming lung fibroblasts for 3 weeks on pathologically stiff substrates resulted in sustained myofibroblast activity even after the cells were returned to healthy soft cultures for 2 weeks. Such primed cells retained higher fibrotic activity than cells that had been exclusively cultured on soft substrates, and were not statistically different from cells continuously passaged on stiff surfaces. Inversely, priming lung fibroblasts for 3 weeks on soft substrates partially protected from myofibroblast activation after the shift to stiff substrates. Hence, mechano-sensed information relating to physical conditions of the local cellular environment could permanently induce fibrotic behavior of lung fibroblasts. This priming effect has important implications for the progression and persistence of aggressive fibrotic diseases such as idiopathic pulmonary fibrosis.

A lack of host-derived SPARC promotes disease progression in an intraperitoneal (IP) ID8 mouse model of epithelial ovarian cancer (EOC). Since orthotopic injection (OT) of ID8 cells better recapitulates high-grade serous cancer, we examined the impact of host-derived SPARC following OT injection. Sparc(-/-) and wild-type (WT) mice were injected with ID8 cells either OT or IP and tumors were analyzed at the moribund stage. Sparc(-/-) mice had reduced survival and fewer well-defined abdominal lesions compared with WT controls after IP injection, whereas no differences were observed in survival or abdominal lesions between Sparc(-/-) and WT mice after OT injection. No differences in mass or collagen content were observed in ovarian tumors between OT-injected Sparc(-/-) and WT mice. The abdominal wall of the IP-injected Sparc(-/-) mice exhibited immature and less abundant collagen fibrils compared with WT mice both in injected and non-injected controls. In contrast to human EOC, SPARC was expressed by the tumor cells but was absent in reactive stroma of WT mice. Exposure to the ovarian microenvironment through OT injections alters the metastatic behaviour of ID8 cells, which is not affected by the absence of host-derived SPARC.

SummaryDipetarudin was coupled to polyethylene glycol (PEG)-5000 residues in order to improve its pharmacokinetic profile and to enhance its anticoagulant efficacy. The resulting compounds, mono-and di-PEGylated dipetarudin were purified by gel filtration. Mono-PEGylated dipetarudin exhibited similar activity like its non-conjugated equivalent both in vitro and in vivo. However, di-PEGylated dipetarudin showed longer distribution and elimination half-lives and higher area under the time-concentration curve in comparison with the unmodified inhibitor which may be attributed to decreased renal clearance. Futhermore, ratio k 12/k 21 decreased when the number of PEG chains coupled to dipetarudin increased. It means that the intercompartment transfer of dipetarudin, characterised by a fast distribution and a high retention in the peripheral compartment, is reverted by coupling to PEG. Thus, the transfer of mono-PEGylated dipetarudin between these compartments is similar in both senses and the transfer of di-PEGylated dipetarudin is slower from vascular to extravascular compartment than vice versa. Our results show that di-PEGylated dipetarudin produces a better and longer anticoagulant effect than unmodified dipetarudin which is a desirable attribute for future therapeutic application.

The matricellular glycoprotein SPARC is composed of three functional domains that are evolutionarily conserved in organisms ranging from nematodes to mammals: a Ca(2+)-binding glutamic acid-rich acidic domain at the N-terminus (domain I), a follistatin-like module (domain II), and an extracellular Ca(2+)-binding (EC) module that contains two EF-hands and two collagen-binding epitopes (domain III). We report that four SPARC orthologs (designated nvSPARC1-4) are expressed by the genome of the starlet anemone Nematostella vectensis, a diploblastic basal cnidarian composed of an ectoderm and endoderm separated by collagen-based mesoglea. We also report that domain I is absent from all N. vectensis SPARC orthologs. In situ hybridization data indicate that N. vectensis SPARC mRNAs are restricted to the endoderm during post-gastrula development. The absence of the Ca(2+)-binding N-terminal domain in cnidarians and conservation of collagen-binding epitopes suggests that SPARC first evolved as a collagen-binding matricellular glycoprotein, an interaction likely to be dependent on the binding of Ca(2+)-ions to the two EF-hands in the EC domain. We propose that further Ca(2+)-dependent activities emerged with the acquisition of an acidic N-terminal module in triplobastic organisms.

A new species of microsporidian, Trichonosema algonquinensis, is described from a freshwater bryozoan, Pectinatella magnifica from Ontario, Canada. The parasite develops in epithelial cells and appears as white, spherical masses throughout the tissues. Trichonosema algonquinensis is diplokaryotic, diploblastic and undergoes development in direct contact with the cytoplasm of the host cell. Mature spores are ovoid, tapered at one end, and measure 8.5 +/- 0.3 x 4.4 +/- 0.1 microm. The polar filament is wound in 20 to 23 helical coils. Although the parasite resembles T. pectinatellae described from the same host in Michigan and Ohio, it differs in the length of the spore and number of coils of the polar filament. Analysis of 16S rDNA by maximum likelihood, parsimony and Baysian inference, complements the morphological data in supporting the placement of T. algonquinensis as a sister species of T. pectinatellae.

In retrospective studies, CALR mutation is found to be a favorable prognostic variable in myelofibrosis (MF) compared with JAK2, or MPL mutations. With the availability of the JAK1/JAK2 inhibitor ruxolitinib (RUX) for treatment of MF, it is not yet known whether response varies across mutational subgroups and whether the prognostic implication of the driver mutations in terms of survival (OS) changes under RUX. We studied the prevalence and prognostic weight of clinical parameters in the IPSS and DIPSS-plus and the impact of RUX on OS in the context of mutation status. Patient and Methods: As of November 2009, RUX for treatment of splenomegaly and/or constitutional symptoms became an option at the University of Leipzig. All patients (pt) with MF seen since then were included (n=127; f=43%, median age 58 years) with the exception of pt with MPL mut+ because of small number. Screening for the JAK2V617F and CALR mutations was performed as previously published. Cytogenetic-risk categorization was conducted as published (Caramazza et al. Leukemia 2011). Results: JAK2 mut+ (group A; 60.6%) constituted the largest group, followed by CALR mut+ (group B; 19.7%), and “triple-negative” (group C; 19.7%). The median duration of MF was 22 months with no difference in the 3 groups. Higher-risk IPSS was present in the majority [Int-II 34.4%; high-risk 42.4%]. Constitutional symptoms were present across all groups, although more frequent in group A which was also characterized by prominent splenomegaly (Table). Group B pt were younger with low WBC in contrast to goup C pt who were older, anemic, with high WBC and low platelets, unfavorable cytogenetics and high-risk IPSS. Hb < 100 g/L (54%), and transfusion-dependency (32%) were frequently present in group B and was similar to group A. RUX was given to 72 (57%) pt [graoup A (66%), group B (56%), group C (29%)] with a median exposure of 8 months. The response of 80% was not influenced by the mutation status, cytogenetics, or IPSS variables. Leukemic transformation was documented in 22 pt [14 (64%) pt had no RUX exposure] after a median of 18 months after diagnosis. The incidence was highest in group C (36%) and lowest in group B (4%) (p=0.004). Unfavorable cytogenetics were 75%, and 27% in group C and A respectively. After a median follow-up of 31 months, OS at 3-years was 82% and worst in group C (72%) vs 80% for group A (p=0.05) vs 96% in goup B (p=0.003). In univariate analysis, non-mutated status (p=0.02), Int-2/high-risk IPSS (p=0.06), anemia (p=0.03), transfusion dependency (p=0.04), and platelets < 100 x109/L (p=0.06) but not unfavorable cytogenetics were associated with an inferior OS. In multivariate analysis, advanced IPSS only (p=0.04) but not the mutation status (p=0.4) retained its negative impact on OS. Generally, in group A pt treated with RUX (n=50), OS was only marginally inferior to group B (p=0.08). In pt with int-2/high-risk IPSS, OS in group A with RUX (n=41) was similar to that of group B (p=0.4). Conclusions: The mutation status in MF bestows distinct clinical phenotypes and has crucial prognostic and therapeutic implications. Patients with non-mutated MF had the worst prognosis, unfavourable cytogenetics, and the highest rate of leukemic transformation. Although the IPSS retains its value, the prognostic power of certain factors such as anemia and constitutional symptoms in CALR-mutated pt needs to be re-evaluated. Response to ruxolitinib seems to be independent of the mutation status. More importantly, a JAK1/JAK2 inhibition appears to be capable of attenuating the prognostic implication of the different mutation profiles by improving the less-favorable survival associated with non-CALR-mutated MF through a disease-modifying effect. The full potential of a sustained JAK1/JAK2 inhibition in modifying survival in the context of the various mutational profiles needs to be further studied in a larger cohort of patients. Table Clinical variables in patients with different driver mutations Variable JAK2 mut+ CALR mut+ Triple-negative p N (%) 77 (60.6) 25 (19.7) 25 (19.7) Median age (years) 59 51 61 0.02 Constitutional symptoms (%) 69 52 46 0.08 Median palpable spleen (cm) 10 4 3 0.001 Int-2/high-risk IPSS (%) 79 52 96 0.01 WBC > 25 x109/L (%) 21 11.5 44 0.008 Median peripheral blasts (%) 1 0.5 2 ns Median Hb (g/L) 106 99 86 0.008 Hb < 100 g/L (%) 42 54 80 0.03 Transfusion dependency (%) 33 32 67 0.009 Platelets < 100 x109/L (%) 30 8 52 0.04 Unfavorable cytogenetics (%) 31 14 48 0.06 Disclosures Al-Ali: Novartis: Honoraria, Research Funding. Jaekel:Novartis: Honoraria. Lange:Novartis: Honoraria. Roskos:Novartis: Honoraria. Niederwieser:Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.

In 1999, 4 species of cyprinid were surveyed for myxozoan parasites in a watershed in Algonquin Park, Canada; Kathlyn Lake, Broadwing Lake, and Lake Sasajewun were included. Eight species of Myxobolus were found that differed in their prevalence and distribution among the 3 lakes. The oligochaetes and environmental parameters, including sediment types and aquatic plants, of these 3 lakes were surveyed the following year. Oligochaetes belonging to 17 species were collected from the 3 lakes. The distribution patterns of the oligochaete fauna, with respect to the environmental variables, were examined using canonical correspondence analysis. Naidids were predominant in all 3 lakes, particularly in the pebbly and sandy sediment of Lake Sasajewun. The highest percentage of tubificids occurred in the detritus and muddy substrate of Broadwing Lake. These findings indicate that the prevalence of certain oligochaetes is congruent with the absence or presence of particular myxozoan species and that substrates and aquatic plants influence the distribution of certain oligochaete species.

In this paper R R denotes an associative ring with an identity, and all modules are unital left R R -modules. It is shown that the existence of a quasi-projective cover for each module implies that each module has a projective cover. By a similar technique the following statements are shown to be equivalent: 1. R R is semisimple and Artinian; 2. Every finitely generated module is quasi-projective; and 3. The direct sum of every pair of quasi-projective modules is quasi-projective. Direct sums of quasi-injective modules are also investigated.