The dynamic nature of gene expression enables cellular programming, homeostasis, and environmental adaptation in living systems. Dissection of causal gene functions in cellular and organismal processes therefore necessitates approaches that enable spatially and temporally precise modulation of gene expression. Recently, a variety of microbial and plant-derived light-sensitive proteins have been engineered as optogenetic actuators, enabling high precision spatiotemporal control of many cellular functions1-11. However, versatile and robust technologies that enable optical modulation of transcription in the mammalian endogenous genome remain elusive. Here, we describe the development of Light-Inducible Transcriptional Effectors (LITEs), an optogenetic two-hybrid system integrating the customizable TALE DNA-binding domain12-14 with the light-sensitive cryptochrome 2 protein and its interacting partner CIB1 from Arabidopsis thaliana. LITEs do not require additional exogenous chemical co-factors, are easily customized to target many endogenous genomic loci, and can be activated within minutes with reversibility3,4,6,7,15. LITEs can be packaged into viral vectors and genetically targeted to probe specific cell populations. We have applied this system in primary mouse neurons, as well as in the brain of awake mice in vivo to mediate reversible modulation of mammalian endogenous gene expression as well as targeted epigenetic chromatin modifications. The LITE system establishes a novel mode of optogenetic control of endogenous cellular processes and enables direct testing of the causal roles of genetic and epigenetic regulation in normal biological processes and disease states.
Our aim was to reliably identify patients with advanced-stage classical Hodgkin lymphoma (cHL) at increased risk of death by developing a robust predictor of overall survival (OS) using gene expression measured in routinely available formalin-fixed paraffin-embedded tissue (FFPET).
Expression levels of 259 genes, including those previously reported to be associated with outcome in cHL, were determined by digital expression profiling of pretreatment FFPET biopsies from 290 patients enrolled onto the E2496 Intergroup trial comparing doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) and Stanford V regimens in locally extensive and advanced-stage cHL. A model for OS separating patients into low- and high-risk groups was produced using penalized Cox regression. The model was tested in an independent cohort of 78 patients enriched for treatment failure but otherwise similar to patients in a population-based registry of patients treated with ABVD. Weighted analysis methods generated unbiased estimates of predictor performance in the population-based registry.
A 23-gene outcome predictor was generated. The model identified a population at increased risk of death in the validation cohort. There was a 29% absolute difference in 5-year OS between the high- and low-risk groups (63% v 92%, respectively; log-rank P < .001; hazard ratio, 6.7; 95% CI, 2.6 to 17.4). The predictor was superior to the International Prognostic Score and CD68 immunohistochemistry in multivariate analyses.
A gene expression–based predictor, developed in and applicable to routinely available FFPET biopsies, identifies patients with advanced-stage cHL at increased risk of death when treated with standard-intensity up-front regimens.
Using the foraging movements of an insectivorous bat, Myotis mystacinus, we describe temporal switching of foraging behaviour in response to resource availability. These observations conform to predictions of optimized search under the Lévy flight paradigm. However, we suggest that this occurs as a result of a preference behaviour and knowledge of resource distribution. Preferential behaviour and knowledge of a familiar area generate distinct movement patterns as resource availability changes on short temporal scales. The behavioural response of predators to changes in prey fields can elicit different functional responses, which are considered to be central in the development of stable predator–prey communities. Recognizing how the foraging movements of an animal relate to environmental conditions also elucidates the evolution of optimized search and the prevalence of discrete strategies in natural systems. Applying techniques that use changes in the frequency distribution of movements facilitates exploration of the processes that underpin behavioural changes.
Lévy flight; functional responses; bats; areoecology
The genome of Leishmania mexicana encompasses a cluster of three glucose transporter genes designated LmxGT1, LmxGT2, and LmxGT3. Functional and genetic studies of a cluster null mutant (Δlmxgt1-3) have dissected the roles of these proteins in Leishmania metabolism and virulence. However, null mutants were recovered at very low frequency, and comparative genome hybridizations revealed that Δlmxgt1-3 mutants contained a linear extrachromosomal 40 kb amplification of a region on chromosome 29 not amplified in WT parasites. These data suggested a model where this 29–40k amplicon encoded a second site suppressor contributing to parasite survival in the absence of GT1-3 function. To test this, we quantified the frequency of recovery of knockouts in the presence of individual overexpressed ORFs covering the 29–40k amplicon. The data mapped the suppressor activity to PIFTC3, encoding a component of the intraflagellar transport pathway. We discuss possible models by which PIFTC3 might act to facilitate loss of GTs specifically. Surprisingly, by plasmid segregation we showed that continued PIFTC3 overexpression was not required for Δlmxgt1-3 viability. These studies provide the first evidence that genetic suppression can occur by providing critical biological functions transiently. This novel form of genetic suppression may extend to other genes, pathways and organisms.
Development and optimization of novel species-specific microsatellites, or simple sequence repeats (SSRs) remains an important step for studies in ecology, evolution, and behavior. Numerous approaches exist for identifying new SSRs that vary widely in terms of both time and cost investments. A recent approach of using paired-end Illumina sequence data in conjunction with the bioinformatics pipeline, PAL_FINDER, has the potential to substantially reduce the cost and labor investment while also improving efficiency. However, it does not appear that the approach has been widely adopted, perhaps due to concerns over its broad applicability across taxa. Therefore, to validate the utility of the approach we developed SSRs for 32 species representing 30 families, 25 orders, 11 classes, and six phyla and optimized SSRs for 13 of the species. Overall the IPE method worked extremely well and we identified 1000s of SSRs for all species (mean = 128,485), with 17% of loci being potentially amplifiable loci, and 25% of these met our most stringent criteria designed to that avoid SSRs associated with repetitive elements. Approximately 61% of screened primers yielded strong amplification of a single locus.
Up-regulated expression of endothelial adhesion molecules and subsequent binding to cognate monocytic receptors is an established paradigm in atherosclerosis. However, these proteins are the scaffolds with their post-translational modification with sugars providing the actual ligands. We showed recently that TNFα increased hypoglycosylated (mannose rich) N-glycans on the endothelial surface. In this study our aim was to determine if i) hypoglycosylated N-glycans are upregulated by pro-atherogenic stimuli (oscillatory flow) in vitro and in vivo, and ii) whether mannose residues on hypoglycosylated endothelial N-glycans mediate monocyte rolling and adhesion.
Methods and result
Staining with the mannose specific lectins ConA and LCA was increased in human aortic endothelial cells exposed to oscillatory shear or TNFα, and at sites of plaque development and progression in both mice and human vessels. Increasing surface N-linked mannose by inhibiting N-glycan processing, potentiated monocyte adhesion under flow during TNFα stimulation. Conversely, enzymatic removal of high-mannose N-glycans, or masking mannose residues with lectins, significantly decreased monocyte adhesion under flow. These effects occurred without altering induced expression of adhesion molecule proteins.
Hypoglycosylated (high mannose) N-glycans are present on the endothelial cell surface at sites of early human lesion development and are novel effectors of monocyte adhesion during atherogenesis.
mannose; inflammation; vascular; adhesion; glycobiology
Penicillins inhibit cell wall synthesis; therefore, H. pylori must be dividing for this class of antibiotics to be effective in eradication therapy. Identifying growth responses to varying medium pH may allow design of more effective treatment regimens.
To determine the effect of acidity on bacterial growth and the bactericidal efficacy of ampicillin.
H. pylori were incubated in dialysis chambers suspended in 1.5L of media at various pHs with 5mM urea, with or without ampicillin, for 4, 8 or 16 hours, thus mimicking unbuffered gastric juice. Changes in gene expression, viability and survival were determined.
At pH 3.0, but not at pH 4.5 or 7.4, there was decreased expression of ~400 genes, including many cell envelope biosynthesis, cell division and penicillin-binding protein genes. Ampicillin was bactericidal at pH 4.5 and 7.4 but not at pH 3.0.
Ampicillin is bactericidal at pH 4.5 and 7.4, but not at pH 3.0, due to decreased expression of cell envelope and division genes with loss of cell division at pH 3.0. Therefore, at pH 3.0, the likely pH at the gastric surface, the bacteria are non-dividing and persist with ampicillin treatment. A more effective inhibitor of acid secretion that maintains gastric pH near neutrality for 24 hours/day should enhance the efficacy of amoxicillin, improving triple therapy and likely even allowing dual amoxicillin based therapy for H. pylori eradication.
Helicobacter pylori; medium pH; bacterial growth; ampicillin/amoxicillin; gastric acid inhibition; proton pump inhibitor
In this perspective, we revise the historic notion that cancer is a disease of mitochondria. We summarize recent findings on the function and rewiring of central carbon metabolism in melanoma. Metabolic profiling studies using stable isotope tracers show that glycolysis is decoupled from the tricarboxylic acid (TCA) cycle. This decoupling is not ‘dysfunction’ but rather an alternate wiring required by tumor cells to remain metabolically versatile. In large part, this requirement is met by glutamine feeding the TCA cycle as an alternative source of carbon. Glutamine is also used in non-conventional ways, like traveling in reverse through the TCA flux to feed fatty acid biosynthesis. The biosynthetic networks linked with non-essential amino acids alanine, serine, arginine, and proline are also significantly impacted by the use of glutamine as an alternate carbon source.
metabolism; mitochondria; glutamine; systems biology; NMR
Sphingolipids (SLs) play essential roles in most eukaryotes, but in the trypanosomatid protozoan Leishmania major their functions differ significantly. Previously we showed that null mutants defective in de novo sphingoid base synthesis (spt2−) lacked SLs but grew well and retained lipid rafts while replicating as promastigotes in vitro. However, they experienced catastrophic defects in membrane trafficking on entry into stationary phase, and failed to differentiate to the infective metacyclic form. Here we showed this mutant retained the ability to enter macrophages silently and inhibit activation, although as expected most parasites were destroyed. However, in mouse infections, after a delay rapidly progressive lesions appeared, and purified amastigotes were fully virulent to macrophages and mice. Mass spectrometry of spt2− amastigote lipids revealed the presence of high levels of parasite-specific inositol phosphorylceramides (IPCs) not synthesized by the mammalian hosts. Inhibitor studies showed that salvage occurs at the level of complex SLs, suggesting that parasites carry out ‘headgroup’ remodelling. Additionally, we describe a new defect of the spt2− promastigotes involving ‘empty’ acidocalcisomes (ACs), which may point to the origin of this organelle from the lysosome-related organelle/multivesicular body biogenesis pathway. However, ACs in spt2− amastigotes appeared quantitatively and morphologically normal. Thus salvage of SLs and other molecules by intracellular amastigotes play key roles in AC biogenesis and parasite survival in the host.
Diabetes is the leading cause of chronic kidney disease, and the prevalence of both diseases is rising worldwide. Treatment of type 2 diabetes is difficult in patients with chronic kidney disease because most oral antidiabetic agents are affected by renal function and their use may be contraindicated in this patient population. Antidiabetic agents that can be used in patients with type 2 diabetes and declining renal function are needed. Incretin-based therapies, such as dipeptidyl peptidase-4 inhibitors, are a recent therapeutic class of glucose-lowering agents that may offer an effective treatment option in patients with chronic kidney disease. Within the dipeptidyl peptidase-4 class, linagliptin has a unique profile with a primarily nonrenal route of elimination, requiring no dose adjustment in patients with chronic kidney disease. This communication summarizes the findings of a 1-year, randomized, double-blind, placebo-controlled study demonstrating the favorable safety and efficacy profile of linagliptin in patients with type 2 diabetes and severe renal impairment.
renal impairment; incretin; DPP-4 inhibitor; type 2 diabetes
Diffuse large B-cell lymphoma (DLBCL) is curable in 60% of patients treated with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP). MYC translocations, with or without BCL2 translocations, have been associated with inferior survival in DLBCL. We investigated whether expression of MYC protein, with or without BCL2 protein expression, could risk-stratify patients at diagnosis.
Patients and Methods
We determined the correlation between presence of MYC and BCL2 proteins by immunohistochemistry (IHC) with survival in two independent cohorts of patients with DLBCL treated with R-CHOP. We further determined if MYC protein expression correlated with high MYC mRNA and/or presence of MYC translocation.
In the training cohort (n = 167), MYC and BCL2 proteins were detected in 29% and 44% of patients, respectively. Concurrent expression (MYC positive/BCL2 positive) was present in 21% of patients. MYC protein correlated with presence of high MYC mRNA and MYC translocation (both P < .001), but the latter was less frequent (both 11%). MYC protein expression was only associated with inferior overall and progression-free survival when BCL2 protein was coexpressed (P < .001). Importantly, the poor prognostic effect of MYC positive/BCL2 positive was validated in an independent cohort of 140 patients with DLBCL and remained significant (P < .05) after adjusting for presence of high-risk features in a multivariable model that included elevated international prognostic index score, activated B-cell molecular subtype, and presence of concurrent MYC and BCL2 translocations.
Assessment of MYC and BCL2 expression by IHC represents a robust, rapid, and inexpensive approach to risk-stratify patients with DLBCL at diagnosis.
To describe the long-term (≥ 10 years) benefits of clinical human papillomavirus (HPV) DNA testing for cervical precancer and cancer risk prediction.
Cervicovaginal lavages collected from 19,512 women attending a health maintenance program were retrospectively tested for HPV using a clinical test. HPV positives were tested for HPV16 and HPV18 individually using a research test. A Papanicolaou (Pap) result classified as atypical squamous cells of undetermined significance (ASC-US) or more severe was considered abnormal. Women underwent follow-up prospectively with routine annual Pap testing up to 18 years. Cumulative incidence rates (CIRs) of ≥ grade 3 cervical intraepithelial neoplasia (CIN3+) or cancer for enrollment test results were calculated.
A baseline negative HPV test provided greater reassurance against CIN3+ over the 18-year follow-up than a normal Pap (CIR, 0.90% v 1.27%). Although both baseline Pap and HPV tests predicted who would develop CIN3+ within the first 2 years of follow-up, only HPV testing predicted who would develop CIN3+ 10 to 18 years later (P = .004). HPV16- and HPV18-positive women with normal Pap were at elevated risk of CIN3+ compared with other HPV-positive women with normal Pap and were at similar risk of CIN3+ compared with women with a low-grade squamous intraepithelial Pap.
HPV testing to rule out cervical disease followed by Pap testing and possibly combined with the detection of HPV16 and HPV18 among HPV positives to identify those at immediate risk of CIN3+ would be an efficient algorithm for cervical cancer screening, especially in women age 30 years or older.
Objective. To assess the prevalence and characteristics of curriculum in dual doctor of pharmacy (PharmD)/master of public health (MPH) degree programs offered by US pharmacy programs.
Methods. An 18-item survey instrument was developed and distributed online to faculty members at US colleges and schools of pharmacy.
Results. Of the 110 colleges and schools that responded, 23 (21%) offered a PharmD/MPH degree. Common characteristics of these 23 programs included current PharmD program structure (3 + 1 year), early curricular recruitment, small enrollment, and interdisciplinary coursework occurring online and in the classroom. The impact of the dual degree on the curriculum and longevity of the dual-degree programs varied. About 55% of responding programs without a formal dual-degree program reported that additional public health training was available.
Conclusion. Twenty-one percent of colleges and schools of pharmacy offer a combined PharmD/MPH dual degree. Most programs required an additional 1 or 2 semesters to complete both degrees.
pharmacy education; public health; masters of public health; dual degree
Endothelial cell responses during inflammation are heterogeneous and key for selectivity in how leukocytes hone in on specific sites and why vascular diseases are highly bed specific. However, mechanisms for this specificity remain unclear.
Methods and Results
Here, we exposed human endothelial cells isolated from 5 systemic arterial beds from 1 donor (to overcome donor‐to‐donor genetic/epigenetic differences), the umbilical vein, and pulmonary microvasculature to TNF‐α, LPS, and IL‐1β and assessed acute (ERK1/2 and p65) and chronic (ICAM‐1, VCAM‐1 total and surface expression) signaling responses and assessed changes in surface N‐glycans and monocyte adhesion. Significant diversity in responses was evident by disparate changes in ERK1/2 and p65 NF‐κB phosphorylation, which varied up to 5‐fold between different cells and in temporal and magnitude differences in ICAM‐1 and VCAM‐1 expression (maximal VCAM‐1 induction typically being observed by 4 hours, whereas ICAM‐1 expression was increased further at 24 hours relative to 4 hours). N‐glycan profiles both basally and with stimulation were also bed specific, with hypoglycosylated N‐glycans correlating with increased THP‐1 monocyte adhesion. Differences in surface N‐glycan expression tracked with dynamic up‐ or downregulation of α‐mannosidase activity during inflammation.
These results demonstrate a critical role for the vascular bed of origin in controlling endothelial responses and function to inflammatory stimuli and suggest that bed‐specific expression of N‐linked sugars may provide a signature for select leukocyte recruitment.
heterogeneity; mannose; N‐glycans
Despite advances in the understanding of diffuse large B-cell lymphoma (DLBCL) biology, only the clinically based International Prognostic Index (IPI) is used routinely for risk stratification at diagnosis. To find novel prognostic markers, we analyzed flow cytometric data from 229 diagnostic DLBCL samples using an automated multiparameter data analysis approach developed in our laboratory. By using the developed automated data analysis pipeline, we identified 71 of 229 cases as having more than 35% B cells with a high side scatter (SSC) profile, a parameter reflecting internal cellular complexity. This high SSC B-cell feature was associated with inferior overall and progression-free survival (P = .001 and P = .01, respectively) and remained a significant predictor of overall survival in multivariate Cox regression analysis (IPI, P = .001; high SSC, P = .004; rituximab, P = .53).
This study suggests that high SSC among B cells may serve as a useful biomarker to identify patients with DLBCL at high risk for relapse. This is of particular interest because this biomarker is readily available in most clinical laboratories without significant alteration to existing routine diagnostic strategies or incurring additional costs.
Side scatter; Flow cytometry; Diffuse large B-cell lymphoma; Lymphoma; Survival
Rheumatoid arthritis (RA) remains a major clinical problem with many patients having continuing systemic inflammatory disease resulting in progressive erosive damage and high levels of disability. A range of pro-inflammatory cytokines including tumor necrosis factor (TNF), interleukin (IL)-1 and IL-6 are involved in RA pathogenesis; these cytokines can be specifically inhibited by biological agents. Tocilizumab (TCZ) is a recombinant humanized anti-IL-6 receptor monoclonal antibody, administered monthly by intravenous infusion that prevents IL-6 signal transduction. There is strong evidence that it is both clinically efficacious and cost-effective. There have been several key clinical trials evaluating the safety and efficacy of TCZ in RA patients. We review five Phase II trials and seven Phase III trials enrolling a total of 626 and 5268 RA patients respectively. The American College of Rheumatology (ACR) response criteria were used as the primary or secondary outcome measure in all trials. Overall these trials demonstrated that TCZ was effective in the treatment of RA in a number of patient groups, including those with an inadequate response to methotrexate (MTX) or TNF inhibition. TCZ use, both as monotherapy and in combination with MTX, improved the signs and symptoms of RA within several weeks of commencing treatment. Additionally, TCZ was shown to reduce radiological disease progression and improve physical function, both as monotherapy and in combination with MTX. A 5-year extension study demonstrated that TCZ sustained good long-term efficacy and safety profiles. TCZ was generally well tolerated. Although its use increased the risk of an adverse event, these were usually mild to moderate in severity and treatment did not increase the risk of a serious adverse event in comparison to controls. Due to moderate increases in serum levels of total cholesterol, triglycerides, high-density lipoproteins and serum transaminases seen in those patients treated with TCZ, as well as severe neutropenia in some, regular blood monitoring of full blood count, liver function and lipids is recommended. Given its clinical efficacy in the treatment of RA, TCZ may be beneficial in the treatment of other autoimmune diseases where IL-6 plays a role in the inflammatory cascade.
tocilizumab; rheumatoid arthritis; review; IL-6
Signal Regulatory Protein γ (SIRPγ) is a member of a closely related family of three cell surface receptors implicated in modulating immune/inflammatory responses. SIRPγ is expressed on T lymphocytes where it appears to be involved in the integrin-independent adhesion of lymphocytes to antigen-presenting cells. Here we describe the first full length structure of the extracellular region of human SIRPγ.
We obtained crystals of SIRPγ by making a complex of the protein with the Fab fragment of the anti-SIRP antibody, OX117, which also binds to SIRPα and SIRPβ. We show that the epitope for FabOX117 is formed at the interface of the first and second domains of SIRPγ and comprises residues which are conserved between all three SIRPs. The FabOX117 binding site is distinct from the region in domain 1 which interacts with CD47, the physiological ligand for both SIRPγ and SIRPα but not SIRPβ. Comparison of the three domain structures of SIRPγ and SIRPα showed that these receptors can adopt different overall conformations due to the flexibility of the linker between the first two domains. SIRPγ in complex with FabOX117 forms a dimer in the crystal. Binding to the Fab fixes the position of domain 1 relative to domains 2/3 exposing a surface which favours formation of a homotypic dimer. However, the interaction appears to be relatively weak since only monomers of SIRPγ were observed in sedimentation velocity analytical ultracentrifugation of the protein alone. Studies of complex formation by equilibrium ultracentrifugation showed that only a 1:1 complex of SIRPγ: FabOX117 was formed with a dissociation constant in the low micromolar range (Kd = 1.2 +/− 0.3 μM).
The three-domain extracellular regions of SIRPs are structurally conserved but show conformational flexibility in the disposition of the amino terminal ligand-binding Ig domain relative to the two membrane proximal Ig domains. Binding of a cross-reactive anti-SIRP Fab fragment to SIRPγ stabilises a conformation that favours SIRP dimer formation in the crystal structure, though this interaction does not appear sufficiently stable to be observed in solution.
Antigen-binding complex; Signal regulatory protein; Receptor structure
Slow axonal transport conveys perikaryally-synthesized cytosolic proteins in a rate-class called Slow Component-b (SCb). One such protein – α-synuclein – is largely conveyed in SCb, and is also a key player in a group of neurodegenerative diseases called synucleinopathies. Axonal transport defects of α-synuclein have been hypothesized to play a role in synucleinopathies, but mechanisms moving α-synuclein in slow axonal transport are unclear. Here we use a recently developed model-system in our laboratory to visualize the slow transport of α-synuclein, comparing it to another SCb protein synapsin. Despite differences inbiological properties and overallsolubility in axons, the anterograde transport of both SCb proteins was strikingly similar, suggesting commonalities in slow axonal transport mechanisms of seemingly diverse cytosolic cargoes. The data support a model where SCb proteins dynamically organize into ‘transport-competent’ complexes that are conveyed via transient associations with other persistently-moving cargoes (“mobile-units”). The identity of the latter is yet unknown. Visualizing normal α-synuclein transport may also open the door to studies of α-synuclein transport in pathologic states.
Cytosolic synaptic proteins; synapsin; α-synuclein; slow axonal transport; transport packets; cargo complexes; diffusion; slow component – b; SCb
The TCA cycle is the central hub of oxidative metabolism, running in the classic forward direction to provide carbon for biosynthesis and reducing agents for generation of ATP. Our metabolic tracer studies in melanoma cells showed that in hypoxic conditions the TCA cycle is largely disconnected from glycolysis. By studying the TCA branch point metabolites, acetyl CoA and citrate, as well as the metabolic endpoints glutamine and fatty acids, we developed a comprehensive picture of the rewiring of the TCA cycle that occurs in hypoxia. Hypoxic tumor cells maintain proliferation by running the TCA cycle in reverse. The source of carbon for acetyl CoA, citrate, and fatty acids switches from glucose in normoxia to glutamine in hypoxia. This hypoxic flux from glutamine into fatty acids is mediated by reductive carboxylation. This reductive carboxylation is catalyzed by two isocitrate dehydrogenases, IDH1 and IDH2. Their combined action is necessary and sufficient to effect the reverse TCA flux and maintain cellular viability.
Objectives. Granulomatosis with polyangiitis (Wegener's) (GPA) and microscopic polyangiitis (MPA) are uncommon and have unknown aetiology. The aim of the study was to investigate the epidemiology of GPA and MPA in a stable, well-defined population looking for differences in the pattern of occurrence, which might suggest a different aetiology.
Methods. Since 1988, we have maintained a prospective register of all patients with systemic vasculitis attending the Norfolk and Norwich University Hospital. Patients presenting with new-onset GPA and MPA as defined by the European Medicines Agency algorithm and registered with general practitioners in the former Norwich Health Authority area between 1988 and 2010 were identified. The population in 2008 was estimated to be 459 000 (221 000 males).
Results. One hundred and eleven GPA and 58 MPA incident cases were identified during 1988–2010. The overall annual incidence of GPA and MPA was 11.3/million and 5.9/million, respectively. There was evidence of a cyclical pattern of occurrence with a periodicity of 7.6 years for GPA with a peak incidence of 28.3/million in 2005 and the lowest in 2002 (2.2/million). Other lesser peaks occurred in 1990 and 1996. While the peak incidence of MPA was in 2008 (15.2/million), there was no convincing evidence of periodicity. The incidence of cANCA/PR3- or pANCA/MPO-positive vasculitis showed a similar pattern to GPA and MPA, respectively.
Conclusion. This study lends support to the notion that the aetiology of GPA and MPA may be distinct conditions with different aetiologies. The cyclical incidence of GPA is possibly an indication for the influence of infection.
granulomatosis with polyangiitis (Wegener's); Wegener's granulomatosis; microscopic polyangiitis; epidemiology; vasculitis
HLA class II-restricted regulatory T cell (Treg) epitopes in IgG (also called “Tregitopes”) have been reported to suppress immune responses to coadministered antigens by stimulating the expansion of natural Tregs (nTregs). Here we evaluate their impact on human immune responses to islet cell antigens ex vivo and on the modulation of type 1 diabetes (T1D) in a murine model in vivo. Co-administration of Tregitopes and T1D antigens delayed development of hyperglycemia and reduced the incidence of diabetes in NOD mice. Suppression of diabetes could be observed even following onset of disease. To measure the impact of Tregitope treatment on T cell responses, we evaluated the effect of Tregitope treatment in DO11.10 mice. Upregulation of FoxP3 in KJ1-26-stained OVA-specific CD4+ T cells was observed following treatment of DO11.10 mice with Tregitopes, along with reductions in anti-OVA Ig and T effector responses. In ex vivo studies of human T cells, peripheral blood mononuclear cells' (PBMC) responses to GAD65 epitopes in the presence and absence of Tregitope were variable. Suppression of immune responses to GAD65 epitopes ex vivo by Tregitope appeared to be more effective in assays using PBMC from a newly diagnosed diabetic subject than for other more established diabetic subjects, and correlation of the degree of suppression with predicted HLA restriction of the Tregitopes was confirmed. Implementation of these defined regulatory T cell epitopes for therapy of T1D and other autoimmune diseases may lead to a paradigm shift in disease management.
Helicobacter pylori survives and grows at low pHs via acid acclimation mechanisms that enable periplasmic pH homeostasis. Important components include a cytoplasmic urease; a pH-gated urea channel, UreI; and periplasmic α-carbonic anhydrase. To allow the rapid adjustment of periplasmic pH, acid acclimation components are recruited to the inner membrane in acid. The ArsRS two-component system, in an acid-responsive manner, controls the transcription of the urease gene cluster and α-carbonic anhydrase. The aim of this study is to determine the role of ArsS in protein trafficking as a component of acid acclimation. H. pylori wild-type and ΔarsS bacteria were incubated at acidic and neutral pHs. Intact bacteria, purified membranes, and total protein were analyzed by Western blotting and urease activity measurements. The total urease activity level was decreased in the ΔarsS strain, but the acid activation of UreI was unaffected. A 30-min acid exposure increased the level and activity of urease proteins at the membrane in the wild type but not in the ΔarsS strain. The urease levels and activity of the ΔarsS strain after a 90-min acid exposure were similar to those of the wild type. ArsS, in addition to its role in urease gene transcription, is also involved in the recruitment of urease proteins to the inner membrane to augment acid acclimation during acute acid exposure. Urease membrane recruitment following prolonged acid exposure in the absence of ArsS was similar to that of the wild type, suggesting a compensatory mechanism, possibly regulated by FlgS, underscoring the importance of urease membrane recruitment and activation in periplasmic pH homeostasis.
We report the case of a 64-year-old patient in whom a pulmonary artery catheter formed a knot fixed within the right ventricle in the region of the tricuspid valve apparatus. Knot formation is a recognized complication associated with pulmonary artery catheters (PAC) insertion. This problem is usually dealt with by simply withdrawing the PAC until the knot impacts onto the introducer and after enlarging the puncture site by a small skin incision removing the introducer-PAC as one unit. However, we recently encountered a situation where the PAC was knotted around the tricuspid valve apparatus and could not be withdrawn. An interventional radiologist was able to unknot the catheter and release it from the tricuspid valve. We reviewed the literature related to this topic. We believe our experience could be of use to others.
Invasive hemodynamic monitoring; pulmonary artery catheter; pulmonary artery catheter complications; tricuspid valve
Complementary and alternative medicine includes a number of exercise modalities, such as tai chi, qigong, yoga, and a variety of lesser-known movement therapies. A meta-analysis of the current literature was conducted estimating the effect size of the different modalities, study quality and bias, and adverse events. The level of research has been moderately weak to date, but most studies report a medium-to-high effect size in pain reduction. Given the lack of adverse events, there is little risk in recommending these modalities as a critical component in a multimodal treatment plan, which is often required for fibromyalgia management.
fibromyalgia; exercise; complementary and alternative; efficacy; safety
The downstream targets of amyloid β (Aβ)-oligomers remain elusive. One hypothesis is that Aβ-oligomers interrupt axonal transport. Although previous studies have demonstrated Aβ-induced transport blockade, early effects of low-n soluble Aβ-oligomers on axonal transport remain unclear. Furthermore, the cargo selectivity for such deficits (if any) or the specific effects of Aβ on the motility kinetics of transported cargoes are also unknown. Toward this, we visualized axonal transport of vesicles in cultured hippocampal neurons treated with picomolar (pm) levels of cell-derived soluble Aβ-oligomers. We examined select cargoes thought to move as distinct organelles and established imaging parameters that allow organelle tracking with consistency and high fidelity – analyzing all data in a blinded fashion. Aβ-oligomers induced early and selective diminutions in velocities of synaptic cargoes but had no effect on mitochondrial motility, contrary to previous reports. These changes were N-methyl d-aspartate receptor/glycogen synthase kinase-3β dependent and reversible upon washout of the oligomers. Cluster-mode analyses reveal selective attenuations in faster-moving synaptic vesicles, suggesting possible decreases in cargo/motor associations, and biochemical experiments implicate tau phosphorylation in the process. Collectively, the data provide a biological basis for Aβ-induced axonal transport deficits.
amyloid β-oligomers; axonal transport; cargo-motor regulation; molecular motors; synaptic loss; transport packets