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Sample records for aashto type iv

  1. Interplanetary Type IV Bursts

    NASA Astrophysics Data System (ADS)

    Hillaris, A.; Bouratzis, C.; Nindos, A.

    2016-08-01

    We study the characteristics of moving type IV radio bursts that extend to hectometric wavelengths (interplanetary type IV or type {IV}_{{IP}} bursts) and their relationship with energetic phenomena on the Sun. Our dataset comprises 48 interplanetary type IV bursts observed with the Radio and Plasma Wave Investigation (WAVES) instrument onboard Wind in the 13.825 MHz - 20 kHz frequency range. The dynamic spectra of the Radio Solar Telescope Network (RSTN), the Nançay Decametric Array (DAM), the Appareil de Routine pour le Traitement et l' Enregistrement Magnetique de l' Information Spectral (ARTEMIS-IV), the Culgoora, Hiraso, and the Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation (IZMIRAN) Radio Spectrographs were used to track the evolution of the events in the low corona. These were supplemented with soft X-ray (SXR) flux-measurements from the Geostationary Operational Environmental Satellite (GOES) and coronal mass ejections (CME) data from the Large Angle and Spectroscopic Coronagraph (LASCO) onboard the Solar and Heliospheric Observatory (SOHO). Positional information of the coronal bursts was obtained by the Nançay Radioheliograph (NRH). We examined the relationship of the type IV events with coronal radio bursts, CMEs, and SXR flares. The majority of the events (45) were characterized as compact, their duration was on average 106 minutes. This type of events was, mostly, associated with M- and X-class flares (40 out of 45) and fast CMEs, 32 of these events had CMEs faster than 1000 km s^{-1}. Furthermore, in 43 compact events the CME was possibly subjected to reduced aerodynamic drag as it was propagating in the wake of a previous CME. A minority (three) of long-lived type {IV}_{{IP}} bursts was detected, with durations from 960 minutes to 115 hours. These events are referred to as extended or long duration and appear to replenish their energetic electron content, possibly from electrons escaping from the corresponding coronal

  2. Genetics Home Reference: mucopolysaccharidosis type IV

    MedlinePlus

    ... it is called MPS IV type A (MPS IVA), and when it is caused by mutations in ... Rare Diseases Information Center (1 link) Mucopolysaccharidosis type IVA Additional NIH Resources (1 link) National Institute of ...

  3. Observational properties of decameter type IV bursts

    NASA Astrophysics Data System (ADS)

    Melnik, Valentin; Brazhenko, Anatoly; Rucker, Helmut; Konovalenko, Alexander; Briand, Carine; Dorovskyy, Vladimir; Zarka, Philippe; Frantzusenko, Anatoly; Panchenko, Michael; Poedts, Stefan; Zaqarashvili, Teimuraz; Shergelashvili, Bidzina

    2013-04-01

    Oscillations of decameter type IV bursts were registered during observations of solar radio emission by UTR-2, URAN-2 and NDA in 2011-2012. Large majority of these bursts were accompanied by coronal mass ejections (CMEs), which were observed by SOHO and STEREO in the visible light. Only in some cases decameter type IV bursts were not associated with CMEs. The largest periods of oscillations P were some tens of minutes. There were some modes of long periods of oscillations simultaneously. Periods of oscillations in flux and in polarization profiles were close. Detailed properties of oscillations at different frequencies were analyzed on the example of two type IV bursts. One of them was observed on April 7, 2011 when a CME happened. Another one (August 1, 2011) was registered without any CME. The 7 April type IV burst had two periods in the frames 75-85 and 35-85 minutes. Interesting feature of these oscillations is decreasing periods with time. The observed decreasing rates dP/dt equaled 0.03-0.07. Concerning type IV burst observed on August 1, 2011 the period of its oscillations increases from 17 min. at 30 MHz to 44 min. at 10 MHz. Connection of type IV burst oscillations with oscillations of magnetic arches and CMEs at corresponding altitudes are discussed. The work is fulfilled in the frame of FP7 project "SOLSPANET".

  4. Type IV Pilin Proteins: Versatile Molecular Modules

    PubMed Central

    Giltner, Carmen L.; Nguyen, Ylan

    2012-01-01

    Summary: Type IV pili (T4P) are multifunctional protein fibers produced on the surfaces of a wide variety of bacteria and archaea. The major subunit of T4P is the type IV pilin, and structurally related proteins are found as components of the type II secretion (T2S) system, where they are called pseudopilins; of DNA uptake/competence systems in both Gram-negative and Gram-positive species; and of flagella, pili, and sugar-binding systems in the archaea. This broad distribution of a single protein family implies both a common evolutionary origin and a highly adaptable functional plan. The type IV pilin is a remarkably versatile architectural module that has been adopted widely for a variety of functions, including motility, attachment to chemically diverse surfaces, electrical conductance, acquisition of DNA, and secretion of a broad range of structurally distinct protein substrates. In this review, we consider recent advances in this research area, from structural revelations to insights into diversity, posttranslational modifications, regulation, and function. PMID:23204365

  5. Reconstruction for Type IV Radial Polydactyly.

    PubMed

    Wall, Lindley B; Goldfarb, Charles A

    2015-09-01

    Type IV radial polydactyly represents a thumb with an extra proximal and distal phalanx. Assessment of the thumb for surgical reconstruction includes observing thumb function, evaluating thumb size and stability, and assessing the first web space. Reconstruction includes excision of the smaller thumb, typically the radial thumb, and re-creating thumb stability and alignment by addressing tendon insertion and joint orientation. Although surgical results are satisfying and complications are uncommon, additional surgical intervention may be required over time owing to thumb malalignment or instability.

  6. The Mosaic Type IV Secretion Systems

    PubMed Central

    Christie, Peter J.

    2016-01-01

    Escherichia coli and other Gram-negative and -positive bacteria employ type IV secretion systems (T4SSs) to translocate DNA and protein substrates, generally by contact-dependent mechanisms, to other cells. The T4SSs functionally encompass two major subfamilies, the conjugation systems and the effector translocators. The conjugation systems are responsible for interbacterial transfer of antibiotic resistance genes, virulence determinants, and genes encoding other traits of potential benefit to the bacterial host. The effector translocators are used by many Gram-negative pathogens for delivery of potentially hundreds of virulence proteins termed effectors to eukaryotic cells during infection. In E. coli and other species of Enterobacteriaceae, T4SSs identified to date function exclusively in conjugative DNA transfer. In these species, the plasmid-encoded systems can be classified as the P, F, and I types. The P-type systems are the simplest in terms of subunit composition and architecture, and members of this subfamily share features in common with the paradigmatic Agrobacterium tumefaciens VirB/VirD4 T4SS. This review will summarize our current knowledge of the E. coli systems and the A. tumefaciens P-type system, with emphasis on the structural diversity of the T4SSs. Ancestral P-, F-, and I-type systems were adapted throughout evolution to yield the extant effector translocators, and information about well-characterized effector translocators also is included to further illustrate the adaptive and mosaic nature of these highly versatile machines. PMID:27735785

  7. Re-Evaluation of the AASHTO-Flexible Pavement Design Equation with Neural Network Modeling

    PubMed Central

    Tiğdemir, Mesut

    2014-01-01

    Here we establish that equivalent single-axle loads values can be estimated using artificial neural networks without the complex design equality of American Association of State Highway and Transportation Officials (AASHTO). More importantly, we find that the neural network model gives the coefficients to be able to obtain the actual load values using the AASHTO design values. Thus, those design traffic values that might result in deterioration can be better calculated using the neural networks model than with the AASHTO design equation. The artificial neural network method is used for this purpose. The existing AASHTO flexible pavement design equation does not currently predict the pavement performance of the strategic highway research program (Long Term Pavement Performance studies) test sections very accurately, and typically over-estimates the number of equivalent single axle loads needed to cause a measured loss of the present serviceability index. Here we aimed to demonstrate that the proposed neural network model can more accurately represent the loads values data, compared against the performance of the AASHTO formula. It is concluded that the neural network may be an appropriate tool for the development of databased-nonparametric models of pavement performance. PMID:25397962

  8. Re-evaluation of the AASHTO-flexible pavement design equation with neural network modeling.

    PubMed

    Tiğdemir, Mesut

    2014-01-01

    Here we establish that equivalent single-axle loads values can be estimated using artificial neural networks without the complex design equality of American Association of State Highway and Transportation Officials (AASHTO). More importantly, we find that the neural network model gives the coefficients to be able to obtain the actual load values using the AASHTO design values. Thus, those design traffic values that might result in deterioration can be better calculated using the neural networks model than with the AASHTO design equation. The artificial neural network method is used for this purpose. The existing AASHTO flexible pavement design equation does not currently predict the pavement performance of the strategic highway research program (Long Term Pavement Performance studies) test sections very accurately, and typically over-estimates the number of equivalent single axle loads needed to cause a measured loss of the present serviceability index. Here we aimed to demonstrate that the proposed neural network model can more accurately represent the loads values data, compared against the performance of the AASHTO formula. It is concluded that the neural network may be an appropriate tool for the development of databased-nonparametric models of pavement performance.

  9. Genetics Home Reference: glycogen storage disease type IV

    MedlinePlus

    ... and can lead to joint stiffness (arthrogryposis) after birth. Infants with the fatal perinatal neuromuscular type of GSD IV have very low muscle tone (severe hypotonia) and muscle wasting (atrophy). ...

  10. Type IV pili mechanochemically regulate virulence factors in Pseudomonas aeruginosa

    PubMed Central

    Persat, Alexandre; Inclan, Yuki F.; Engel, Joanne N.; Stone, Howard A.; Gitai, Zemer

    2015-01-01

    Bacteria have evolved a wide range of sensing systems to appropriately respond to environmental signals. Here we demonstrate that the opportunistic pathogen Pseudomonas aeruginosa detects contact with surfaces on short timescales using the mechanical activity of its type IV pili, a major surface adhesin. This signal transduction mechanism requires attachment of type IV pili to a solid surface, followed by pilus retraction and signal transduction through the Chp chemosensory system, a chemotaxis-like sensory system that regulates cAMP production and transcription of hundreds of genes, including key virulence factors. Like other chemotaxis pathways, pili-mediated surface sensing results in a transient response amplified by a positive feedback that increases type IV pili activity, thereby promoting long-term surface attachment that can stimulate additional virulence and biofilm-inducing pathways. The methyl-accepting chemotaxis protein-like chemosensor PilJ directly interacts with the major pilin subunit PilA. Our results thus support a mechanochemical model where a chemosensory system measures the mechanically induced conformational changes in stretched type IV pili. These findings demonstrate that P. aeruginosa not only uses type IV pili for surface-specific twitching motility, but also as a sensor regulating surface-induced gene expression and pathogenicity. PMID:26041805

  11. Epidermal cells adhere preferentially to type IV (basement membrane) collagen

    PubMed Central

    1979-01-01

    Epidermal cells from adult guinea pig skin attach and differentiate preferentially on substrates of type IV (basement membrane) collagen, compared to those of types I--III collagen. In contrast, guinea pig dermal fibroblasts attach equally well to all four collagen substrates. Fibronectin mediates the attachment of fibroblasts but not of epidermal cells to collagen. PMID:422650

  12. Archaeal type IV pili and their involvement in biofilm formation

    PubMed Central

    Pohlschroder, Mechthild; Esquivel, Rianne N.

    2015-01-01

    Type IV pili are ancient proteinaceous structures present on the cell surface of species in nearly all bacterial and archaeal phyla. These filaments, which are required for a diverse array of important cellular processes, are assembled employing a conserved set of core components. While type IV pilins, the structural subunits of pili, share little sequence homology, their signal peptides are structurally conserved allowing for in silico prediction. Recently, in vivo studies in model archaea representing the euryarchaeal and crenarchaeal kingdoms confirmed that several of these pilins are incorporated into type IV adhesion pili. In addition to facilitating surface adhesion, these in vivo studies also showed that several predicted pilins are required for additional functions that are critical to biofilm formation. Examples include the subunits of Sulfolobus acidocaldarius Ups pili, which are induced by exposure to UV light and promote cell aggregation and conjugation, and a subset of the Haloferax volcanii adhesion pilins, which play a critical role in microcolony formation while other pilins inhibit this process. The recent discovery of novel pilin functions such as the ability of haloarchaeal adhesion pilins to regulate swimming motility may point to novel regulatory pathways conserved across prokaryotic domains. In this review, we will discuss recent advances in our understanding of the functional roles played by archaeal type IV adhesion pili and their subunits, with particular emphasis on their involvement in biofilm formation. PMID:25852657

  13. Archaeal type IV pili and their involvement in biofilm formation.

    PubMed

    Pohlschroder, Mechthild; Esquivel, Rianne N

    2015-01-01

    Type IV pili are ancient proteinaceous structures present on the cell surface of species in nearly all bacterial and archaeal phyla. These filaments, which are required for a diverse array of important cellular processes, are assembled employing a conserved set of core components. While type IV pilins, the structural subunits of pili, share little sequence homology, their signal peptides are structurally conserved allowing for in silico prediction. Recently, in vivo studies in model archaea representing the euryarchaeal and crenarchaeal kingdoms confirmed that several of these pilins are incorporated into type IV adhesion pili. In addition to facilitating surface adhesion, these in vivo studies also showed that several predicted pilins are required for additional functions that are critical to biofilm formation. Examples include the subunits of Sulfolobus acidocaldarius Ups pili, which are induced by exposure to UV light and promote cell aggregation and conjugation, and a subset of the Haloferax volcanii adhesion pilins, which play a critical role in microcolony formation while other pilins inhibit this process. The recent discovery of novel pilin functions such as the ability of haloarchaeal adhesion pilins to regulate swimming motility may point to novel regulatory pathways conserved across prokaryotic domains. In this review, we will discuss recent advances in our understanding of the functional roles played by archaeal type IV adhesion pili and their subunits, with particular emphasis on their involvement in biofilm formation.

  14. Biological role of prolyl 3-hydroxylation in type IV collagen.

    PubMed

    Pokidysheva, Elena; Boudko, Sergei; Vranka, Janice; Zientek, Keith; Maddox, Kerry; Moser, Markus; Fässler, Reinhard; Ware, Jerry; Bächinger, Hans Peter

    2014-01-07

    Collagens constitute nearly 30% of all proteins in our body. Type IV collagen is a major and crucial component of basement membranes. Collagen chains undergo several posttranslational modifications that are indispensable for proper collagen function. One of these modifications, prolyl 3-hydroxylation, is accomplished by a family of prolyl 3-hydroxylases (P3H1, P3H2, and P3H3). The present study shows that P3H2-null mice are embryonic-lethal by embryonic day 8.5. The mechanism of the unexpectedly early lethality involves the interaction of non-3-hydroxylated embryonic type IV collagen with the maternal platelet-specific glycoprotein VI (GPVI). This interaction results in maternal platelet aggregation, thrombosis of the maternal blood, and death of the embryo. The phenotype is completely rescued by producing double KOs of P3H2 and GPVI. Double nulls are viable and fertile. Under normal conditions, subendothelial collagens bear the GPVI-binding sites that initiate platelet aggregation upon blood exposure during injuries. In type IV collagen, these sites are normally 3-hydroxylated. Thus, prolyl 3-hydroxylation of type IV collagen has an important function preventing maternal platelet aggregation in response to the early developing embryo. A unique link between blood coagulation and the ECM is established. The newly described mechanism may elucidate some unexplained fetal losses in humans, where thrombosis is often observed at the maternal/fetal interface. Moreover, epigenetic silencing of P3H2 in breast cancers implies that the interaction between GPVI and non-3-hydroxylated type IV collagen might also play a role in the progression of malignant tumors and metastasis.

  15. Terminal ileum gangrene secondary to a type IV paraesophageal hernia.

    PubMed

    Hsu, Ching Tsai; Hsiao, Po Jen; Chiu, Chih Chien; Chan, Jenq Shyong; Lin, Yee Fung; Lo, Yuan Hung; Hsiao, Chia Jen

    2016-02-28

    Type IV paraesophageal hernia (PEH) is very rare, and is characterized by the intrathoracic herniation of the abdominal viscera other than the stomach into the chest. We describe a 78-year-old woman who presented at our emergency department because of epigastric pain that she had experienced over the past 24 h. On the day after admission, her pain became severe and was accompanied by right chest pain and dyspnea. Chest radiography revealed an intrathoracic intestinal gas bubble occupying the right lower lung field. Emergency explorative laparotomy identified a type IV PEH with herniation of only the terminal ileum through a hiatal defect into the right thoracic cavity. In this report, we also present a review of similar cases in the literature published between 1980 and 2015 in PubMed. There were four published cases of small bowel herniation into the thoracic cavity during this period. Our patient represents a rare case of an individual diagnosed with type IV PEH with incarceration of only the terminal ileum.

  16. Adult presentation of Bartter syndrome type IV with erythrocytosis

    PubMed Central

    Heilberg, Ita Pfeferman; Tótoli, Cláudia; Calado, Joaquim Tomaz

    2015-01-01

    Abstract Bartter syndrome comprises a group of rare autosomal-recessive salt-losing disorders with distinct phenotypes, but one unifying pathophysiology consisting of severe reductions of sodium reabsorption caused by mutations in five genes expressed in the thick ascending limb of Henle, coupled with increased urinary excretion of potassium and hydrogen, which leads to hypokalemic alkalosis. Bartter syndrome type IV, caused by loss-of-function mutations in barttin, a subunit of chloride channel CLC-Kb expressed in the kidney and inner ear, usually occurs in the antenatal-neonatal period. We report an unusual case of late onset presentation of Bartter syndrome IV and mild phenotype in a 20 years-old man who had hypokalemia, deafness, secondary hyperparathyroidism and erythrocytosis. PMID:26537508

  17. SPECIFIC AND NON-SPECIFIC POLYSACCHARIDES OF TYPE IV PNEUMOCOCCUS

    PubMed Central

    Heidelberger, Michael; Kendall, Forrest E.

    1931-01-01

    1. Three nitrogen-containing polysaccharides have been isolated from autolyzed cultures of Type IV pneumococcus: (1) a type-specific carbohydrate differing markedly from those of Type I, II, and III pneumococcus, and representing a type of substance hitherto not observed among specific polysaccharides, (2) a chemically similar carbohydrate without specific function, and (3) the "C" substance, or species-specific polysaccharide of Tillett, Goebel, and Avery. 2. The chemical differences between the specific polysaccharides of Pneumococcus are discussed, and the relationship of the new examples to chitin is pointed out and its bearing indicated on the unsettled controversy as to whether or not chitin occurs in bacteria. 3. The data of Tillett, Goebel, and Avery on the "C" substance have been extended. PMID:19869869

  18. Symptomatic Type IV Dual Left Anterior Descending Coronary Artery

    PubMed Central

    Papadopoulos, Kyriacos; Georgiou, Georgios M.; Nicolaides, Evagoras

    2016-01-01

    Dual left anterior descending coronary artery is a rare congenital anomaly with 4 subtypes. Double left anterior descending coronary artery originating from the left main stem and the right coronary artery (type IV dual left anterior descending artery) has been reported to occur in 0.01% to 0.7% of patients undergoing cardiac catheterization. We report a case of a 49-year-old woman who was found to have this anomaly during coronary angiography. The patient had been complaining of chest pain that mimics angina pectoris and exercise tolerance test was positive for myocardial ischemia. PMID:28203572

  19. Mechanical stability study of type IV cryomodule (ILC prototype)

    SciTech Connect

    McGee, M.W.; Doremus, R.; Wands, C.R.; /Fermilab

    2007-06-01

    An ANSYS modal and harmonic finite element analysis (FEA) was performed in order to investigate cryomodule design mechanical stability for the proposed International Linear Collider (ILC). The current cryomodule, designated Type IV or (T4CM), closely follows the Type III TESLA Test Facility (TTF) version used at DESY, with the exception of a proposed location of the superconducting (SC) quadrupole at the center. This analysis considered the stringent stability criteria established for the ILC, where vertical motion for the SC quadrupole is limited to the micron range at a few Hz. Model validation was achieved through Type III cryomodule vibration measurement studies performed at DESY. The effect of support location, support stiffness and other important parameters were considered in a parametric sensitivity study. FEA results, fast motion investigations and stabilization techniques are discussed.

  20. Clinical presentations of Ehlers Danlos syndrome type IV.

    PubMed Central

    Pope, F M; Narcisi, P; Nicholls, A C; Liberman, M; Oorthuys, J W

    1988-01-01

    Ehlers Danlos syndrome type IV is an often lethal disease caused by various mutations of type III collagen genes. It presents in infancy and childhood in several ways, and the symptoms and signs include low birth weight, prematurity, congenital dislocation of the hips, easy inappropriate bruising (sometimes suspected as child battering), and a diagnostic facial phenotype. These features predict a lethal adult disease often complicated by fatal arterial rupture in early or middle adult life. Most affected patients can be diagnosed from radiolabelled collagen protein profiles by polyacrylamide gel electrophoresis. Prenatal diagnosis by specific type III collagen restriction fragment length polymorphisms is possible in some families, and will become increasingly important. Prenatal diagnosis and prevention of the disease in selected families is already possible and will be widely available in the future. Images Fig 1 Fig 2 Fig 3 Fig 4 Fig 5 Fig 6 Fig 7 Fig 8 Fig 9 Fig 10 Fig 11 PMID:3178263

  1. Possible association of elevated serum collagen type IV level with skin sclerosis in systemic sclerosis.

    PubMed

    Motegi, Sei-Ichiro; Sekiguchi, Akiko; Fujiwara, Chisako; Toki, Sayaka; Ishikawa, Osamu

    2016-08-29

    Collagen type IV is the primary collagen in the basement membranes around blood vessels and in the dermoepidermal junction in the skin. Perivascular collagen type IV is synthesized by endothelial cells and pericytes, and contributes to the homeostasis and remodeling of blood vessels. It has been well recognized that elevated serum collagen type IV levels are associated with the liver fibrosis. The objective was to examine serum collagen type IV levels and their clinical associations in patients with systemic sclerosis (SSc), and to examine the expression of collagen type IV in the fibrotic skin in SSc. Serum collagen type IV levels in SSc patients and diffuse cutaneous type SSc patients were significantly higher than those in healthy individuals. Serum collagen type IV levels were positively correlated with modified Rodnan total skin score. Serum collagen type IV levels in early stage (disease duration ≤3 years) diffuse cutaneous SSc patients were significantly elevated. Serum collagen type IV levels in SSc patients with digital ulcers (DU) were significantly elevated. In immunohistochemical staining, the expression of collagen type IV around dermal small vessels in the affected skin was reduced compared with those of normal individuals. These results suggest that elevated serum collagen type IV levels may be associated with the skin sclerosis in the early stage of SSc. The measurement of serum collagen type IV levels in SSc patients may be useful as a disease activity marker in skin sclerosis and DU.

  2. Named entity recognition for bacterial Type IV secretion systems.

    PubMed

    Ananiadou, Sophia; Sullivan, Dan; Black, William; Levow, Gina-Anne; Gillespie, Joseph J; Mao, Chunhong; Pyysalo, Sampo; Kolluru, Balakrishna; Tsujii, Junichi; Sobral, Bruno

    2011-03-29

    Research on specialized biological systems is often hampered by a lack of consistent terminology, especially across species. In bacterial Type IV secretion systems genes within one set of orthologs may have over a dozen different names. Classifying research publications based on biological processes, cellular components, molecular functions, and microorganism species should improve the precision and recall of literature searches allowing researchers to keep up with the exponentially growing literature, through resources such as the Pathosystems Resource Integration Center (PATRIC, patricbrc.org). We developed named entity recognition (NER) tools for four entities related to Type IV secretion systems: 1) bacteria names, 2) biological processes, 3) molecular functions, and 4) cellular components. These four entities are important to pathogenesis and virulence research but have received less attention than other entities, e.g., genes and proteins. Based on an annotated corpus, large domain terminological resources, and machine learning techniques, we developed recognizers for these entities. High accuracy rates (>80%) are achieved for bacteria, biological processes, and molecular function. Contrastive experiments highlighted the effectiveness of alternate recognition strategies; results of term extraction on contrasting document sets demonstrated the utility of these classes for identifying T4SS-related documents.

  3. Conjugative type IV secretion systems in Gram-positive bacteria.

    PubMed

    Goessweiner-Mohr, Nikolaus; Arends, Karsten; Keller, Walter; Grohmann, Elisabeth

    2013-11-01

    Bacterial conjugation presents the most important means to spread antibiotic resistance and virulence factors among closely and distantly related bacteria. Conjugative plasmids are the mobile genetic elements mainly responsible for this task. All the genetic information required for the horizontal transmission is encoded on the conjugative plasmids themselves. Two distinct concepts for horizontal plasmid transfer in Gram-positive bacteria exist, the most prominent one transports single stranded plasmid DNA via a multi-protein complex, termed type IV secretion system, across the Gram-positive cell envelope. Type IV secretion systems have been found in virtually all unicellular Gram-positive bacteria, whereas multicellular Streptomycetes seem to have developed a specialized system more closely related to the machinery involved in bacterial cell division and sporulation, which transports double stranded DNA from donor to recipient cells. This review intends to summarize the state of the art of prototype systems belonging to the two distinct concepts; it focuses on protein key players identified so far and gives future directions for research in this emerging field of promiscuous interbacterial transport.

  4. Named Entity Recognition for Bacterial Type IV Secretion Systems

    PubMed Central

    Black, William; Levow, Gina-Anne; Gillespie, Joseph J.; Mao, Chunhong; Pyysalo, Sampo; Kolluru, BalaKrishna; Tsujii, Junichi; Sobral, Bruno

    2011-01-01

    Research on specialized biological systems is often hampered by a lack of consistent terminology, especially across species. In bacterial Type IV secretion systems genes within one set of orthologs may have over a dozen different names. Classifying research publications based on biological processes, cellular components, molecular functions, and microorganism species should improve the precision and recall of literature searches allowing researchers to keep up with the exponentially growing literature, through resources such as the Pathosystems Resource Integration Center (PATRIC, patricbrc.org). We developed named entity recognition (NER) tools for four entities related to Type IV secretion systems: 1) bacteria names, 2) biological processes, 3) molecular functions, and 4) cellular components. These four entities are important to pathogenesis and virulence research but have received less attention than other entities, e.g., genes and proteins. Based on an annotated corpus, large domain terminological resources, and machine learning techniques, we developed recognizers for these entities. High accuracy rates (>80%) are achieved for bacteria, biological processes, and molecular function. Contrastive experiments highlighted the effectiveness of alternate recognition strategies; results of term extraction on contrasting document sets demonstrated the utility of these classes for identifying T4SS-related documents. PMID:21468321

  5. Ehlers-Danlos Syndrome Type IV: A Case Report.

    PubMed

    Soo-Hoo, Sarah; Porten, Brandon R; Engstrom, Bjorn I; Skeik, Nedaa

    2016-04-01

    Ehlers-Danlos syndrome (EDS) encompasses a group of rare genetic connective tissue disorders. The vascular type (type IV) poses the most serious risk to patients. Diagnosis is usually difficult, especially if patients lack a family history. Life-threatening vascular emergency such as dissection or rupture can be the first presenting symptom. Management of the disease can pose a clinical challenge due to the emergency of presentation, tissue friability, and lack of clear management recommendations. We report a unique case of a 40-year-old man who presented with a ruptured celiac artery and a strong family history of EDS. This case highlights the difficulties and complications associated with treating this uncommon and serious disease.

  6. Bacterial Type IV Secretion Systems: Versatile Virulence Machines

    PubMed Central

    Voth, Daniel E.; Broederdorf, Laura J.; Graham, Joseph G.

    2013-01-01

    Many bacterial pathogens employ multicomponent protein complexes to deliver macromolecules directly into their eukaryotic host cell to promote infection. Some Gram-negative pathogens use a versatile type IV secretion system (T4SS) that can translocate DNA or proteins into host cells. T4SSs represent major bacterial virulence determinants and have recently been the focus of intense research efforts designed to better understand and combat infectious diseases. Interestingly, although the two major classes of T4SSs function in a similar manner to secrete proteins, the translocated “effectors” vary substantially from one organism to another. In fact, differing effector repertoires likely contribute to organism-specific host cell interactions and disease outcomes. In this review, we discuss the current state of T4SS research, with an emphasis on intracellular bacterial pathogens of humans and the diverse array of translocated effectors used to manipulate host cells. PMID:22324993

  7. Structure of the Neisseria meningitidis Type IV pilus

    PubMed Central

    Kolappan, Subramania; Coureuil, Mathieu; Yu, Xiong; Nassif, Xavier; Egelman, Edward H.; Craig, Lisa

    2016-01-01

    Neisseria meningitidis use Type IV pili (T4P) to adhere to endothelial cells and breach the blood brain barrier, causing cause fatal meningitis. T4P are multifunctional polymers of the major pilin protein, which share a conserved hydrophobic N terminus that is a curved extended α-helix, α1, in X-ray crystal structures. Here we report a 1.44 Å crystal structure of the N. meningitidis major pilin PilE and a ∼6 Å cryo-electron microscopy reconstruction of the intact pilus, from which we built an atomic model for the filament. This structure reveals the molecular arrangement of the N-terminal α-helices in the filament core, including a melted central portion of α1 and a bridge of electron density consistent with a predicted salt bridge necessary for pilus assembly. This structure has important implications for understanding pilus biology. PMID:27698424

  8. Judet type-IV radial neck fractures in children

    PubMed Central

    Kaiser, Margarita; Eberl, Robert; Castellani, Christoph; Kraus, Tanja; Till, Holger; Singer, Georg

    2016-01-01

    Background and purpose Heavily displaced radial neck fractures in children are sometimes associated with poor outcome. A substantial number of these fractures require open reduction. We hypothesized that Judet type-IV fractures with a completely displaced radial head would result in a worse outcome than radial neck fractures with remaining bony contact. Patients and methods We analyzed 19 children (median age 9.7 (4–13) years) who were treated for Judet type-IV radial neck fractures between 2001 and 2014. The outcome was assessed at the latest outpatient visit using the Linscheid-Wheeler score at a median time of 3.5 (1–8) years after injury. The patients were assigned either to group A (9 fractures with remaining bony contact between the radial head and the radial neck) or to group B (10 fractures without any bony contact). Results The 2 groups were similar concerning age and sex. The rate of additional injuries was higher in group B (7/10 vs. 1/9 in group A; p = 0.009). The rate of open reduction was higher in group B (5/10 vs. 0/9 in group A; p = 0.01). Poor outcome was more common in group B (4/10 vs. 0/9 in group A; p = 0.03). In group B, the proportion of children with poor outcome (almost half) was the same irrespective of whether open or closed reduction had been done. Interpretation The main causes of unfavorable results of radial neck fracture in children appear to be related to the energy of the injury and the amount of displacement—and not to whether open reduction was used. PMID:27348024

  9. Specific DNA recognition mediated by a type IV pilin

    PubMed Central

    Cehovin, Ana; Simpson, Peter J.; McDowell, Melanie A.; Brown, Daniel R.; Noschese, Rossella; Pallett, Mitchell; Brady, Jacob; Baldwin, Geoffrey S.; Lea, Susan M.; Matthews, Stephen J.; Pelicic, Vladimir

    2013-01-01

    Natural transformation is a dominant force in bacterial evolution by promoting horizontal gene transfer. This process may have devastating consequences, such as the spread of antibiotic resistance or the emergence of highly virulent clones. However, uptake and recombination of foreign DNA are most often deleterious to competent species. Therefore, model naturally transformable Gram-negative bacteria, including the human pathogen Neisseria meningitidis, have evolved means to preferentially take up homotypic DNA containing short and genus-specific sequence motifs. Despite decades of intense investigations, the DNA uptake sequence receptor in Neisseria species has remained elusive. We show here, using a multidisciplinary approach combining biochemistry, molecular genetics, and structural biology, that meningococcal type IV pili bind DNA through the minor pilin ComP via an electropositive stripe that is predicted to be exposed on the filaments surface and that ComP displays an exquisite binding preference for DNA uptake sequence. Our findings illuminate the earliest step in natural transformation, reveal an unconventional mechanism for DNA binding, and suggest that selective DNA uptake is more widespread than previously thought. PMID:23386723

  10. Delayed type IV muscle flap in a feline model.

    PubMed

    Snyder, Ned; Craven, Cameron; Phillips, Linda G

    2006-03-01

    The concept of delaying a skin flap is well established and has been implemented into plastic surgery practice for years. Some investigators have delayed musculocutaneous flaps to improve the perforator inflow. To our knowledge, the concept of delaying a muscle flap had previously never been tested in a model with segmental pedicles. Five cats each underwent 3 sequential operations providing them with a sartorius muscle whose blood supply was a single distal pedicle. The opposite leg was used as a control. Our delayed type IV muscle flap demonstrated perfusion to the proximal tip of the sartorius muscle without necrosis or loss of muscle mass (P < 0.0001). The control showed no evidence of perfusion beyond the distal portion of the muscle when infused through the distal pedicle. The delayed flap can survive on a distal blood supply that would not be adequate in a single-stage procedure. This flap has an increased arc of rotation that may provide solutions to difficult reconstructive problems in the groin, lower abdomen, genitalia, knee, proximal leg, and might be suitable as a free flap.

  11. Type-IV Pilus Deformation Can Explain Retraction Behavior

    PubMed Central

    Ghosh, Ranajay; Kumar, Aloke; Vaziri, Ashkan

    2014-01-01

    Polymeric filament like type IV Pilus (TFP) can transfer forces in excess of 100 pN during their retraction before stalling, powering surface translocation(twitching). Single TFP level experiments have shown remarkable nonlinearity in the retraction behavior influenced by the external load as well as levels of PilT molecular motor protein. This includes reversal of motion near stall forces when the concentration of the PilT protein is loweblack significantly. In order to explain this behavior, we analyze the coupling of TFP elasticity and interfacial behavior with PilT kinetics. We model retraction as reaction controlled and elongation as transport controlled process. The reaction rates vary with TFP deformation which is modeled as a compound elastic body consisting of multiple helical strands under axial load. Elongation is controlled by monomer transport which suffer entrapment due to excess PilT in the cell periplasm. Our analysis shows excellent agreement with a host of experimental observations and we present a possible biophysical relevance of model parameters through a mechano-chemical stall force map. PMID:25502696

  12. Mechanical Properties of Type IV Pili in P. Aeruginosa

    NASA Astrophysics Data System (ADS)

    Lu, Shun; Touhami, Ahmed; Scheurwater, Edie; Harvey, Hanjeong; Burrows, Lori; Dutcher, John

    2009-03-01

    Type IV pili (Tfp) are thin flexible protein filaments that extend from the cell membrane of bacteria such as Pseudomonas aeruginosa and Neisseria gonorrhoeae. The mechanical properties of Tfp are of great importance since they allow bacteria to interact with and colonize various surfaces. In the present study, we have used atomic force microscopy (AFM) for both imaging and pulling on Tfp from P. aeruginosa (PAO1) and from its PilA, PilT, and FliC mutants. A single pilus filament was mechanically stretched and the resulting force-extension profiles were fitted using the worm-like-chain (WLC) model. The statistical distributions obtained for contour length, persistence length, and number of pili per bacteria pole, were used to evaluate the mechanical properties of a single pilus and the biogenesis functions of different proteins (PilA, PilT) involved in its assembly and disassembly. Importantly, the persistence length value of ˜ 1 μm measured in the present study, which is consistent with the curvature of the pili observed in our AFM images, is significantly lower than the value of 5 μm reported earlier by Skerker et al. (1). Our results shed new light on the role of mechanical forces that mediate bacteria-surface interactions and biofilm formation. 1- J.M. Skerker and H.C. Berg, Proc. Natl. Acad. Sci. USA, 98, 6901-6904 (2001).

  13. The spatial organization of Descemet's membrane-associated type IV collagen in the avian cornea

    PubMed Central

    1990-01-01

    The organization of type IV collagen in the unconventional basement membrane of the corneal endothelium (Descemet's membrane) was investigated in developing chicken embryos using anti-collagen mAbs. Both immunofluorescence histochemistry and immunoelectron microscopy were performed. In mature embryos (greater than 15 d of development), the type IV collagen of Descemet's membrane was present as an array of discrete aggregates of amorphous material at the interface between Descemet's membrane and the posterior corneal stroma. Immunoreactivity for type IV collagen was also observed in the posterior corneal stroma as irregular plaques of material with a morphology similar to that of the Descemet's membrane-associated aggregates. This arrangement of Descemet's membrane-associated type IV collagen developed from a subendothelial mat of type IV collagen-containing material. This mat, in which type IV collagen-specific immunoreactivity was always discontinuous, first appeared at the time a confluent endothelium was established, well before the onset of Descemet's membrane formation. Immunoelectron microscopy of mature corneas revealed that the characteristic nodal matrix of Descemet's membrane itself was unreactive for type IV collagen, but was penetrated at intervals by projections of type IV collagen-containing material. These projections frequently appeared to contact cell processes from the underlying corneal endothelium. This spatial arrangement of type IV collagen suggests that it serves to suture the corneal endothelium/Descemet's membrane to the dense interfacial matrix of the posterior stroma. PMID:2182654

  14. Use of right lobe graft with type IV portal vein accompanied by type IV biliary tree in living donor liver transplantation: report of a case

    PubMed Central

    Shehata, Mahmoud Refaat; Jung, Sung-Won; Yu, Young-Dong; Suh, Sung-Ock

    2014-01-01

    Anatomic variations of the portal vein (PV) and bile duct (BD) are more common on the right lobe as compared with left lobe grafts in living donor liver transplantation (LDLT). We recently experienced a case of LDLT for hepatocellular carcinoma combined with liver cirrhosis secondary to hepatitis B virus and hepatitis C virus infection. The only available donor had right lobe graft with type IV PV associated with type IV BD. The patient underwent relaparotomy for PV stenting due to PV stenosis. Percutaneous transhepatic biliary drainage was done for a stricture at the site of biliary reconstruction. Thereafter, the patient was discharged in good health. Our experience suggests that, the use of right lobe graft with type IV PV accompanied by type IV BD should be the last choice for LDLT, because of its technical difficulty and risks of associated complications. PMID:24949326

  15. Evolution of conjugation and type IV secretion systems.

    PubMed

    Guglielmini, Julien; de la Cruz, Fernando; Rocha, Eduardo P C

    2013-02-01

    Genetic exchange by conjugation is responsible for the spread of resistance, virulence, and social traits among prokaryotes. Recent works unraveled the functioning of the underlying type IV secretion systems (T4SS) and its distribution and recruitment for other biological processes (exaptation), notably pathogenesis. We analyzed the phylogeny of key conjugation proteins to infer the evolutionary history of conjugation and T4SS. We show that single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA) conjugation, while both based on a key AAA(+) ATPase, diverged before the last common ancestor of bacteria. The two key ATPases of ssDNA conjugation are monophyletic, having diverged at an early stage from dsDNA translocases. Our data suggest that ssDNA conjugation arose first in diderm bacteria, possibly Proteobacteria, and then spread to other bacterial phyla, including bacterial monoderms and Archaea. Identifiable T4SS fall within the eight monophyletic groups, determined by both taxonomy and structure of the cell envelope. Transfer to monoderms might have occurred only once, but followed diverse adaptive paths. Remarkably, some Firmicutes developed a new conjugation system based on an atypical relaxase and an ATPase derived from a dsDNA translocase. The observed evolutionary rates and patterns of presence/absence of specific T4SS proteins show that conjugation systems are often and independently exapted for other functions. This work brings a natural basis for the classification of all kinds of conjugative systems, thus tackling a problem that is growing as fast as genomic databases. Our analysis provides the first global picture of the evolution of conjugation and shows how a self-transferrable complex multiprotein system has adapted to different taxa and often been recruited by the host. As conjugation systems became specific to certain clades and cell envelopes, they may have biased the rate and direction of gene transfer by conjugation within prokaryotes.

  16. Structural Characterization of Novel Pseudomonas aeruginosa Type IV Pilins

    SciTech Connect

    Nguyen, Y.; Jackson, S; Aidoo, F; Junop, M; Burrows, L

    2010-01-01

    Pseudomonas aeruginosa type IV pili, composed of PilA subunits, are used for attachment and twitching motility on surfaces. P. aeruginosa strains express one of five phylogenetically distinct PilA proteins, four of which are associated with accessory proteins that are involved either in pilin posttranslational modification or in modulation of pilus retraction dynamics. Full understanding of pilin diversity is crucial for the development of a broadly protective pilus-based vaccine. Here, we report the 1.6-{angstrom} X-ray crystal structure of an N-terminally truncated form of the novel PilA from strain Pa110594 (group V), which represents the first non-group II pilin structure solved. Although it maintains the typical T4a pilin fold, with a long N-terminal {alpha}-helix and four-stranded antiparallel {beta}-sheet connected to the C-terminus by a disulfide-bonded loop, the presence of an extra helix in the {alpha}{beta}-loop and a disulfide-bonded loop with helical character gives the structure T4b pilin characteristics. Despite the presence of T4b features, the structure of PilA from strain Pa110594 is most similar to the Neisseria gonorrhoeae pilin and is also predicted to assemble into a fiber similar to the GC pilus, based on our comparative pilus modeling. Interactions between surface-exposed areas of the pilin are suggested to contribute to pilus fiber stability. The non-synonymous sequence changes between group III and V pilins are clustered in the same surface-exposed areas, possibly having an effect on accessory protein interactions. However, based on our high-confidence model of group III PilA{sub PA14}, compensatory changes allow for maintenance of a similar shape.

  17. Characterization of hydra type IV collagen. Type IV collagen is essential for head regeneration and its expression is up-regulated upon exposure to glucose.

    PubMed

    Fowler, S J; Jose, S; Zhang, X; Deutzmann, R; Sarras, M P; Boot-Handford, R P

    2000-12-15

    Hydra vulgaris mesoglea is a primitive basement membrane that also exhibits some features of an interstitial matrix. We have characterized cDNAs that encode the full-length hydra alpha1(IV) chain. The 5169-base pair transcript encodes a protein of 1723 amino acids, including an interrupted 1455-residue collagenous domain and a 228-residue C-terminal noncollagenous domain. N-terminal sequence analyses of collagen IV peptides suggest the molecule is homotrimeric. Denatured hydra type IV collagen protein occurs as dimers and higher order aggregates held together by nonreducible cross-links. Hydra collagen IV exhibits no functional evidence for the presence of a 7 S domain. Type IV collagen is expressed by the ectoderm along the entire longitudinal axis of the animal but is most intense at the base of the tentacles at the site of battery cell transdifferentiation. Antisense studies show that inhibition of collagen IV translation causes a blockage in head regeneration, indicating its importance in normal hydra development. Exposure of adult hydra to 15 mm glucose resulted in up-regulation of type IV collagen mRNA levels within 48 h and significant thickening of the mesoglea within 14 days, suggesting that basement membrane thickening seen in diabetes may be, in evolutionary terms, an ancient glucose-mediated response.

  18. Diversity and Evolution of Type IV pili Systems in Archaea

    PubMed Central

    Makarova, Kira S.; Koonin, Eugene V.; Albers, Sonja-Verena

    2016-01-01

    Many surface structures in archaea including various types of pili and the archaellum (archaeal flagellum) are homologous to bacterial type IV pili systems (T4P). The T4P consist of multiple proteins, often with poorly conserved sequences, complicating their identification in sequenced genomes. Here we report a comprehensive census of T4P encoded in archaeal genomes using sensitive methods for protein sequence comparison. This analysis confidently identifies as T4P components about 5000 archaeal gene products, 56% of which are currently annotated as hypothetical in public databases. Combining results of this analysis with a comprehensive comparison of genomic neighborhoods of the T4P, we present models of organization of 10 most abundant variants of archaeal T4P. In addition to the differentiation between major and minor pilins, these models include extra components, such as S-layer proteins, adhesins and other membrane and intracellular proteins. For most of these systems, dedicated major pilin families are identified including numerous stand alone major pilin genes of the PilA family. Evidence is presented that secretion ATPases of the T4P and cognate TadC proteins can interact with different pilin sets. Modular evolution of T4P results in combinatorial variability of these systems. Potential regulatory or modulating proteins for the T4P are identified including KaiC family ATPases, vWA domain-containing proteins and the associated MoxR/GvpN ATPase, TFIIB homologs and multiple unrelated transcription regulators some of which are associated specific T4P. Phylogenomic analysis suggests that at least one T4P system was present in the last common ancestor of the extant archaea. Multiple cases of horizontal transfer and lineage-specific duplication of T4P loci were detected. Generally, the T4P of the archaeal TACK superphylum are more diverse and evolve notably faster than those of euryarchaea. The abundance and enormous diversity of T4P in hyperthermophilic archaea

  19. Clinical significance of serum laminin and type-IV collagen levels in cutaneous melanoma patients.

    PubMed

    Tas, Faruk; Bilgin, Elif; Karabulut, Senem; Duranyildiz, Derya

    2016-07-01

    Laminin and type-IV collagen constitute a significant portion of the extracellular matrix. The objective of the present study was to evaluate whether the serum concentrations of laminin and type-IV collagen may serve as biomarkers for cutaneous melanoma. Sixty pathologically confirmed melanoma patients were enrolled in the study. Serum laminin and type-IV collagen levels were assessed using an ELISA. Thirty healthy controls were also examined. No significant differences in the baseline serum levels of laminin were identified between melanoma patients and healthy controls (P=0.45). However, the baseline serum levels of type-IV collagen were significantly elevated in melanoma patients compared with those in the control group (P<0.001). Clinical parameters, including patient age, gender, localization of lesion, histopathology, stage of disease, serum lactate dehydrogenase concentrations and responsiveness to chemotherapy were found not to be associated with the serum levels of laminin and type-IV collagen (P>0.05). Furthermore, the serum levels of laminin and type-IV collagen had no prognostic value regarding the outcome for melanoma patients (P=0.36 and P=0.26, respectively). While laminin levels showed no diagnostic value, the serum concentrations of type-IV collagen were indicated to serve as a diagnostic marker in patients with cutaneous melanoma. In conclusion, type-IV collagen levels may be used as a diagnostic marker for cutaneous melanoma, while being void of any prognostic value.

  20. Clinical significance of serum laminin and type-IV collagen levels in cutaneous melanoma patients

    PubMed Central

    TAS, FARUK; BILGIN, ELIF; KARABULUT, SENEM; DURANYILDIZ, DERYA

    2016-01-01

    Laminin and type-IV collagen constitute a significant portion of the extracellular matrix. The objective of the present study was to evaluate whether the serum concentrations of laminin and type-IV collagen may serve as biomarkers for cutaneous melanoma. Sixty pathologically confirmed melanoma patients were enrolled in the study. Serum laminin and type-IV collagen levels were assessed using an ELISA. Thirty healthy controls were also examined. No significant differences in the baseline serum levels of laminin were identified between melanoma patients and healthy controls (P=0.45). However, the baseline serum levels of type-IV collagen were significantly elevated in melanoma patients compared with those in the control group (P<0.001). Clinical parameters, including patient age, gender, localization of lesion, histopathology, stage of disease, serum lactate dehydrogenase concentrations and responsiveness to chemotherapy were found not to be associated with the serum levels of laminin and type-IV collagen (P>0.05). Furthermore, the serum levels of laminin and type-IV collagen had no prognostic value regarding the outcome for melanoma patients (P=0.36 and P=0.26, respectively). While laminin levels showed no diagnostic value, the serum concentrations of type-IV collagen were indicated to serve as a diagnostic marker in patients with cutaneous melanoma. In conclusion, type-IV collagen levels may be used as a diagnostic marker for cutaneous melanoma, while being void of any prognostic value. PMID:27330797

  1. A type IV burst associated with a coronal streamer disruption event

    NASA Technical Reports Server (NTRS)

    Kundu, M. R.

    1987-01-01

    A type IV burst was observed on February 17, 1985 with the Clark Lake Radio Observatory multifrequency radioheliograph operating in the frequency range 20-125 MHz. This burst was associated with a coronal streamer disruption event. From two-dimensional images produced at 50 MHz, evidence of a type II burst and a slow moving type IV burst are shown. The observations of the moving type IV burst suggests that a plasmoid containing energetic electrons can result from the disruption of a coronal streamer.

  2. 7S Fragment of Type IV Collagen as a Serum Marker of Canine Liver Fibrosis.

    PubMed

    Glińska-Suchocka, K; Orłowska, A; Kubiak, K; Spużak, J; Jankowski, M

    2016-09-01

    The aim of this study was to assess whether the serum levels of the 7S fragment of type IV collagen may aid in diagnosing liver fibrosis in dogs. The study was carried out on 20 dogs with liver disease. Serum levels of the 7S fragment of type IV collagen were measured in all dogs. The analysis showed that healthy dogs and dogs with type 1, 2 and 3 liver fibrosis had low serum concentrations of the 7S fragment of type IV collagen compared to dogs with type 4 liver fibrosis. The study revealed that the assessment of serum levels of the 7S fragment of type IV collagen is useful in the diagnosis of advanced liver fibrosis and cirrhosis.

  3. Type IV collagen aggregates promote keratinocyte proliferation and formation of epidermal layer in human skin equivalents.

    PubMed

    Matsuura-Hachiya, Yuko; Arai, Koji Y; Muraguchi, Taichi; Sasaki, Tasuku; Nishiyama, Toshio

    2017-03-07

    Type IV collagen isolated from lens capsule without enzymatic treatment is known to form a gel under physiological condition and influences cellular activities. In case of human keratinocytes, the suppression of proliferation on reconstituted type IV collagen gels was reported in monolayer culture. In this study, we examined effects of type IV collagen isolated from porcine lens capsule on epidermal formation in human skin equivalents. Type IV collagen aggregates were prepared under the culture condition and the aggregates suppressed keratinocyte proliferation in monolayer culture as well as the culture on the gels. In human skin equivalents type IV collagen aggregates were reconstituted on the surface of contracted collagen gels containing human dermal fibroblasts and the keratinocytes were then cultured on the aggregates for 14 days. Interestingly, in human skin equivalents with type IV collagen aggregates, the BrdU-positive keratinocytes were increased and the thickness of the epidermal layer was around twice than that of control culture. Epidermal differentiation markers were expressed in the upper layer of the epidermis and the defined deposition of human basement membrane components were increased at the dermal-epidermal junction. These results indicate that the type IV collagen aggregates stimulate the proliferation of basal keratinocytes and improve the stratification of epidermal layers in human skin equivalents. This article is protected by copyright. All rights reserved.

  4. Type IV collagen is a novel DEJ biomarker that is reduced by radiotherapy.

    PubMed

    McGuire, J D; Gorski, J P; Dusevich, V; Wang, Y; Walker, M P

    2014-10-01

    The dental basement membrane (BM) is composed of collagen types IV, VI, VII, and XVII, fibronectin, and laminin and plays an inductive role in epithelial-mesenchymal interactions during tooth development. The BM is degraded and removed during later-stage tooth morphogenesis; however, its original position defines the location of the dentin-enamel junction (DEJ) in mature teeth. We recently demonstrated that type VII collagen is a novel component of the inner enamel organic matrix layer contiguous with the DEJ. Since it is frequently co-expressed with and forms functional complexes with type VII collagen, we hypothesized that type IV collagen should also be localized to the DEJ in mature human teeth. To identify collagen IV, we first evaluated defect-free erupted teeth from various donors. To investigate a possible stabilizing role, we also evaluated extracted teeth exposed to high-dose radiotherapy--teeth that manifest post-radiotherapy DEJ instability. We now show that type IV collagen is a component within the morphological DEJ of posterior and anterior teeth from individuals aged 18 to 80 yr. Confocal microscopy revealed that immunostained type IV collagen was restricted to the 5- to 10-µm-wide optical DEJ, while collagenase treatment or previous in vivo tooth-level exposure to > 60 Gray irradiation severely reduced immunoreactivity. This assignment was confirmed by Western blotting with whole-tooth crown and enamel extracts. Without reduction, type IV collagen contained macromolecular α-chains of 225 and 250 kDa. Compositionally, our results identify type IV collagen as the first macromolecular biomarker of the morphological DEJ of mature teeth. Given its network structure and propensity to stabilize the dermal-epidermal junction, we propose that a collagen-IV-enriched DEJ may, in part, explain its well-known fracture toughness, crack propagation resistance, and stability. In contrast, loss of type IV collagen may represent a biochemical rationale for the DEJ

  5. Type IV Collagen is a Novel DEJ Biomarker that is Reduced by Radiotherapy

    PubMed Central

    McGuire, J.D.; Gorski, J.P.; Dusevich, V.; Wang, Y.; Walker, M.P.

    2014-01-01

    The dental basement membrane (BM) is composed of collagen types IV, VI, VII, and XVII, fibronectin, and laminin and plays an inductive role in epithelial-mesenchymal interactions during tooth development. The BM is degraded and removed during later-stage tooth morphogenesis; however, its original position defines the location of the dentin-enamel junction (DEJ) in mature teeth. We recently demonstrated that type VII collagen is a novel component of the inner enamel organic matrix layer contiguous with the DEJ. Since it is frequently co-expressed with and forms functional complexes with type VII collagen, we hypothesized that type IV collagen should also be localized to the DEJ in mature human teeth. To identify collagen IV, we first evaluated defect-free erupted teeth from various donors. To investigate a possible stabilizing role, we also evaluated extracted teeth exposed to high-dose radiotherapy – teeth that manifest post-radiotherapy DEJ instability. We now show that type IV collagen is a component within the morphological DEJ of posterior and anterior teeth from individuals aged 18 to 80 yr. Confocal microscopy revealed that immunostained type IV collagen was restricted to the 5- to 10-µm-wide optical DEJ, while collagenase treatment or previous in vivo tooth-level exposure to > 60 Gray irradiation severely reduced immunoreactivity. This assignment was confirmed by Western blotting with whole-tooth crown and enamel extracts. Without reduction, type IV collagen contained macromolecular α-chains of 225 and 250 kDa. Compositionally, our results identify type IV collagen as the first macromolecular biomarker of the morphological DEJ of mature teeth. Given its network structure and propensity to stabilize the dermal-epidermal junction, we propose that a collagen-IV-enriched DEJ may, in part, explain its well-known fracture toughness, crack propagation resistance, and stability. In contrast, loss of type IV collagen may represent a biochemical rationale for the

  6. A Comprehensive Functional Analysis of NTRK1 Missense Mutations Causing Hereditary Sensory and Autonomic Neuropathy Type IV (HSAN IV)

    PubMed Central

    Shaikh, Samiha S.; Chen, Ya‐Chun; Halsall, Sally‐Anne; Nahorski, Michael S.; Omoto, Kiyoyuki; Young, Gareth T.

    2016-01-01

    ABSTRACT Hereditary sensory and autonomic neuropathy type IV (HSAN IV) is an autosomal recessive disorder characterized by a complete lack of pain perception and anhidrosis. Here, we studied a cohort of seven patients with HSAN IV and describe a comprehensive functional analysis of seven novel NTRK1 missense mutations, c.1550G >A, c.1565G >A, c.1970T >C, c.2096T >C, c.2254T >A, c.2288G >C, and c.2311C >T, corresponding to p.G517E, p.G522E, p.L657P, p.I699T, p.C752S, p.C763S, and p.R771C, all of which were predicted pathogenic by in silico analysis. The results allowed us to assess the pathogenicity of each mutation and to gain novel insights into tropomyosin receptor kinase A (TRKA) downstream signaling. Each mutation was systematically analyzed for TRKA glycosylation states, intracellular and cell membrane expression patterns, nerve growth factor stimulated TRKA autophosphorylation, TRKA‐Y496 phosphorylation, PLCγ activity, and neurite outgrowth. We showed a diverse range of functional effects: one mutation appeared fully functional, another had partial activity in all assays, one mutation affected only the PLCγ pathway and four mutations were proved null in all assays. Thus, we conclude that complete abolition of TRKA kinase activity is not the only pathogenic mechanism underlying HSAN IV. By corollary, the assessment of the clinical pathogenicity of HSAN IV mutations is more complex than initially predicted and requires a multifaceted approach. PMID:27676246

  7. A Comprehensive Functional Analysis of NTRK1 Missense Mutations Causing Hereditary Sensory and Autonomic Neuropathy Type IV (HSAN IV).

    PubMed

    Shaikh, Samiha S; Chen, Ya-Chun; Halsall, Sally-Anne; Nahorski, Michael S; Omoto, Kiyoyuki; Young, Gareth T; Phelan, Anne; Woods, Christopher Geoffrey

    2017-01-01

    Hereditary sensory and autonomic neuropathy type IV (HSAN IV) is an autosomal recessive disorder characterized by a complete lack of pain perception and anhidrosis. Here, we studied a cohort of seven patients with HSAN IV and describe a comprehensive functional analysis of seven novel NTRK1 missense mutations, c.1550G >A, c.1565G >A, c.1970T >C, c.2096T >C, c.2254T >A, c.2288G >C, and c.2311C >T, corresponding to p.G517E, p.G522E, p.L657P, p.I699T, p.C752S, p.C763S, and p.R771C, all of which were predicted pathogenic by in silico analysis. The results allowed us to assess the pathogenicity of each mutation and to gain novel insights into tropomyosin receptor kinase A (TRKA) downstream signaling. Each mutation was systematically analyzed for TRKA glycosylation states, intracellular and cell membrane expression patterns, nerve growth factor stimulated TRKA autophosphorylation, TRKA-Y496 phosphorylation, PLCγ activity, and neurite outgrowth. We showed a diverse range of functional effects: one mutation appeared fully functional, another had partial activity in all assays, one mutation affected only the PLCγ pathway and four mutations were proved null in all assays. Thus, we conclude that complete abolition of TRKA kinase activity is not the only pathogenic mechanism underlying HSAN IV. By corollary, the assessment of the clinical pathogenicity of HSAN IV mutations is more complex than initially predicted and requires a multifaceted approach.

  8. Metachronous Bilateral Posterior Tibial Artery Aneurysms in Ehlers-Danlos Syndrome Type IV

    SciTech Connect

    Hagspiel, Klaus D.; Bonatti, Hugo; Sabri, Saher; Arslan, Bulent; Harthun, Nancy L.

    2011-04-15

    Ehlers-Danlos syndrome type IV is a life-threatening genetic connective tissue disorder. We report a 24-year-old woman with EDS-IV who presented with metachronous bilateral aneurysms/pseudoaneurysms of the posterior tibial arteries 15 months apart. Both were treated successfully with transarterial coil embolization from a distal posterior tibial approach.

  9. Farber's disease type IV presenting with cholestasis and neonatal liver failure: report of two cases.

    PubMed

    Willis, Asha; Vanhuse, Cherie; Newton, Kimberly P; Wasserstein, Melissa; Morotti, Raffaella A

    2008-01-01

    We report 2 siblings diagnosed with Farber's disease type IV. Type IV is a subtype of Farber's disease that presents in the neonatal period and usually initially lacks the triad of symptoms, including painful and deformed joints, subcutaneous nodules, and hoarse cry, classically seen in the other subtypes. While it is well known that all neonates with type IV present with hepatomegaly, a previously unrecognized presentation is that of cholestatic jaundice and rapidly evolving liver failure. We describe 2 siblings who presented with jaundice in the neonatal period and discuss the clinical data and variation in pathologic findings that should be considered for the diagnosis.

  10. UNIFICATION OF LUMINOUS TYPE 1 QUASARS THROUGH C IV EMISSION

    SciTech Connect

    Richards, Gordon T.; Kruczek, Nicholas E.; Deo, Rajesh P.; Kratzer, Rachael M.; Gallagher, S. C.; Hall, Patrick B.; Hewett, Paul C.; Leighly, Karen M.; Shen, Yue

    2011-05-15

    Using a sample of {approx}30,000 quasars from the 7th Data Release of the Sloan Digital Sky Survey, we explore the range of properties exhibited by high-ionization, broad emission lines, such as C IV {lambda}1549. Specifically, we investigate the anti-correlation between continuum luminosity and emission-line equivalent width (the Baldwin Effect (BEff)) and the 'blueshifting' of the high-ionization emission lines with respect to low-ionization emission lines. Employing improved redshift determinations from Hewett and Wild, the blueshift of the C IV emission line is found to be nearly ubiquitous, with a mean shift of {approx}810 km s{sup -1} for radio-quiet (RQ) quasars and {approx}360 km s{sup -1} for radio-loud (RL) quasars. The BEff is present in both RQ and RL samples. We consider these phenomena within the context of an accretion disk-wind model that is modulated by the nonlinear correlation between ultraviolet and X-ray continuum luminosity. Composite spectra are constructed as a function of C IV emission-line properties in an attempt to reveal empirical relationships between different line species and the continuum. Within a two-component disk+wind model of the broad emission-line region (BELR), where the wind filters the continuum seen by the disk component, we find that RL quasars are consistent with being dominated by the disk component, while broad absorption line quasars are consistent with being dominated by the wind component. Some RQ objects have emission-line features similar to RL quasars; they may simply have insufficient black hole (BH) spin to form radio jets. Our results suggest that there could be significant systematic errors in the determination of L{sub bol} and BH mass that make it difficult to place these findings in a more physical context. However, it is possible to classify quasars in a paradigm where the diversity of BELR parameters is due to differences in an accretion disk wind between quasars (and over time); these differences are

  11. Salter-Harris type-IV displaced distal radius fracture in a 5-year-old.

    PubMed

    Huntley, Samuel R; Summers, Spencer H; Stricker, Stephen J

    2016-03-01

    Displaced Salter-Harris type-IV fractures are rare in young children and can result in articular incongruity or premature physeal arrest. We describe a 5-year-old boy who sustained a displaced left distal radial Salter-Harris type-IV fracture. The patient had normal wrist function and physeal growth at the 3-year postoperative follow-up. Our patient is by far the youngest reported child with a displaced Salter-Harris type-IV fracture of the distal radius. Prompt anatomic reduction and fixation of a displaced distal radial Salter-Harris type-IV fracture can result in excellent short-term wrist motion with maintenance of physeal function.

  12. Struggling with a Gastric Volvulus Secondary to a Type IV Hiatal Hernia

    PubMed Central

    George, Dafnomilis; Apostolos, Pappas V.; Athanasios, Panoutsopoulos; Emmanuel, Lagoudianakis E.; Nikolaos, Koronakis E.; Nikolaos, Panagiotopoulos; Charalampos, Seretis; George, Karanikas; Andreas, Manouras J.

    2010-01-01

    Type IV hiatal hernias are characterized by herniation of the stomach along with associated viscera such as the spleen, colon, small bowel, and pancreas through the esophageal hiatus. They are relatively rare, representing only about 5%–7% of all hernias, and can be associated with severe complications. We report a 71-year-old veteran wrestler who presented to our department with a type IV paraesophageal hernia containing a gastric volvulus and treated successfully with emergency operation. PMID:20981251

  13. Cells that emerge from embryonic explants produce fibers of type IV collagen

    PubMed Central

    1985-01-01

    Double immunofluorescence staining experiments designed to examine the synthesis and deposition of collagen types I and IV in cultured explants of embryonic mouse lung revealed the presence of connective tissue-like fibers that were immunoreactive with anti-type IV collagen antibodies. This observation is contrary to the widely accepted belief that type IV collagen is found only in sheet-like arrangements beneath epithelia or as a sheath-like layer enveloping bundles of nerve or muscle cells. The extracellular matrix produced by cells that migrate from embryonic mouse lung rudiments in vitro was examined by double indirect immunofluorescence microscopy. Affinity-purified monospecific polyclonal antibodies were used to examine cells after growth on glass or native collagen substrata. The data show that embryonic mesenchymal cells can produce organized fibers of type IV collagen that are not contained within a basement membrane, and that embryonic epithelial cells deposit fibers and strands of type IV collagen beneath their basal surface when grown on glass; however, when grown on a rat tail collagen substratum the epithelial cells produce a fine meshwork. To our knowledge this work represents the first report that type IV collagen can be organized by cells into a fibrous extracellular matrix that is not a basement membrane. PMID:3900085

  14. Specific cleavage of human type III and IV collagens by Pseudomonas aeruginosa elastase.

    PubMed Central

    Heck, L W; Morihara, K; McRae, W B; Miller, E J

    1986-01-01

    Purified Pseudomonas aeruginosa elastase cleaved human type III and IV collagens with the formation of specific cleavage products. Furthermore, type I collagen appeared to be slowly cleaved by both P. aeruginosa elastase and alkaline protease. These cleavage fragments from type III and IV collagens were separated from the intact collagen chains by SDS polyacrylamide gradient gel electrophoresis run under reducing conditions, and they were detected by their characteristic Coomassie blue staining pattern. The results of these studies suggest that the pathogenesis of tissue invasion and hemorrhagic tissue necrosis observed in P. aeruginosa infections may be related to the degradation of these collagen types by bacterial extracellular proteases. Images PMID:3079727

  15. On the Directivity of Low-Frequency Type IV Radio Bursts

    NASA Technical Reports Server (NTRS)

    Gopalswamy, N.; Akiyama, S.; Makela, P.; Yashiro, S.; Cairns, I. H.

    2016-01-01

    An intense type IV radio burst was observed by the STEREO Behind (STB) spacecraft located about 144 deg. behind Earth. The burst was associated with a large solar eruption that occurred on the backside of the Sun (N05E151) close to the disk center in the STB view. The eruption was also observed by the STEREO Ahead (STA) spacecraft (located at 149 deg. ahead of Earth) as an eruption close to the west limb (N05W60) in that view. The type IV burst was complete in STB observations in that the envelope reached the lowest frequency and then receded to higher frequencies. The burst was partial viewed from STA, revealing only the edge coming down to the lowest frequency. The type IV burst was not observed at all near Earth because the source was 61 deg. behind the east limb. The eruption was associated with a low-frequency type II burst observed in all three views, although it was not very intense. Solar energetic particles were also observed at both STEREOs and at SOHO, suggesting that the shock was much extended, consistent with the very high speed of the CME (2048 km/s). These observations suggest that the type IV emission is directed along a narrow cone above the flare site. We confirm this result statistically using the type IV bursts of solar cycle 23.

  16. Type IV Ehlers-Danlos Syndrome: A Surgical Emergency? A Case of Massive Retroperitoneal Hemorrhage.

    PubMed

    Chun, Stephen G; Pedro, Patrick; Yu, Mihae; Takanishi, Danny M

    2011-01-01

    Retroperitoneal hemorrhagic bleeding is a known manifestation of Type-IV Ehlers-Danlos Syndrome that is caused by loss-of-function mutations of the pro-alpha-1 chains of type III pro-collagen (COL3A1) resulting in vascular fragility. A number of previous reports describe futile surgical intervention for retroperitoneal bleeding in Type-IV Ehlers-Danlos Syndrome with high post-operative mortality, although the rarity of retroperitoneal bleeding associated with Type-IV Ehlers-Danlos Syndrome precludes an evidence-based approach to clinical management. We report a 23-year-old male with history of Type-IV Ehlers-Danlos Syndrome who presented with severe abdominal pain and tachycardia following an episode of vomiting. Further work-up of his abdominal pain revealed massive retroperitoneal bleeding by CT-scan of the abdomen. Given numerous cases of catastrophic injury caused by surgical intervention in Type-IV Ehlers-Danlos Syndrome, the patient was treated non-operatively, and the patient made a full recovery. This case suggests that even in cases of large retroperitoneal hemorrhages associated with Ehlers-Danlos Syndrome, it may not truly represent a surgical emergency.

  17. High resolution observations with Artemis-IV and the NRH. I. Type IV associated narrow-band bursts

    NASA Astrophysics Data System (ADS)

    Bouratzis, C.; Hillaris, A.; Alissandrakis, C. E.; Preka-Papadema, P.; Moussas, X.; Caroubalos, C.; Tsitsipis, P.; Kontogeorgos, A.

    2016-02-01

    Context. Narrow-band bursts appear on dynamic spectra from microwave to decametric frequencies as fine structures with very small duration and bandwidth. They are believed to be manifestations of small scale energy release through magnetic reconnection. Aims: We analyzed 27 metric type IV events with embedded narrow-band bursts, which were observed by the ARTEMIS-IV radio spectrograph from 30 June 1999 to 1 August 2010. We examined the morphological characteristics of isolated narrow-band structures (mostly spikes) and groups or chains of structures. Methods: The events were recorded with the SAO high resolution (10 ms cadence) receiver of ARTEMIS-IV in the 270-450 MHz range. We measured the duration, spectral width, and frequency drift of ~12 000 individual narrow-band bursts, groups, and chains. Spike sources were imaged with the Nançay radioheliograph (NRH) for the event of 21 April 2003. Results: The mean duration of individual bursts at fixed frequency was ~100 ms, while the instantaneous relative bandwidth was ~2%. Some bursts had measurable frequency drift, either positive or negative. Quite often spikes appeared in chains, which were closely spaced in time (column chains) or in frequency (row chains). Column chains had frequency drifts similar to type-IIId bursts, while most of the row chains exhibited negative frequently drifts with a rate close to that of fiber bursts. From the analysis of NRH data, we found that spikes were superimposed on a larger, slowly varying, background component. They were polarized in the same sense as the background source, with a slightly higher degree of polarization of ~65%, and their size was about 60% of their size in total intensity. Conclusions: The duration and bandwidth distributions did not show any clear separation in groups. Some chains tended to assume the form of zebra, lace stripes, fiber bursts, or bursts of the type-III family, suggesting that such bursts might be resolved in spikes when viewed with high

  18. Angiogenesis and collagen type IV expression in different endothelial cell culture systems.

    PubMed

    Bahramsoltani, M; Slosarek, I; De Spiegelaere, W; Plendl, J

    2014-04-01

    In vitro angiogenesis assays constitute an important tool for studying the mechanisms of angiogenesis and for identification of pro- and anti-angiogenic substances. Therefore, endothelial cell and media systems used for in vitro angiogenesis assays are required to mimic the angiogenic process in vivo including endothelial capability to express collagen type IV as a component of the basement membrane. In this study, the expression of collagen type IV and its α chains (α1-6) was investigated in different endothelial cell culture systems in vitro qualitatively and quantitatively. These systems included four different batches of microvascular endothelial cells derived from the human skin, heart and lung, from which only two batches were found to be angiogenic and two batches were classified as non-angiogenic. Distribution of the transcripts of the α chains of collagen type IV was similar in all cell and media systems investigated. However, secretion and deposition of a stable extracellular network of collagen type IV could only be observed in the angiogenic cultures. In conclusion, the consecutive steps of the angiogenic cascade in vivo as well as in vitro depend on an increasing secretion and subsequent extracellular deposition of collagen type IV.

  19. Immunohistochemical expression of Type IV Collagen and Autocrine Motility Factor Receptor in Odontogenic Tumours

    PubMed Central

    Sethi, Sneha

    2014-01-01

    Background: Autocrine motility factor receptor (AMFR) is a tumour motility stimulating protein secreted by tumour cells. The protein encoded by this gene is a glycosylated transmembrane protein and a receptor for autocrine motility factor. It has been known to play a role in progression of neoplastic lesions. Basement membranes are specialized extracellular matrices that serve as structural barriers as well as substrates for cellular interactions. The network of type IV collagen is thought to define the scaffold integrating other components such as laminins and perlecan into highly organized supramolecular architecture. The aim of this study was to determine and evaluate the immunohistochemical expression of Type IV Collagen and Autocrine motility factor receptor in odontogenic lesions. Materials and Methods: Immunohistochemical expression of Type IV Collagen and Autocrine motility factor receptor was evaluated in 31 odontogenic lesions, including unicystic ameloblastoma, multicystic ameloblastoma, keratocystic odontogenic tumour and ameloblastic carcinoma. Normal follicular tissue formed the control. Results: Maximum expression for Type IV Collagen was seen in multicystic ameloblastoma and minimum expression in keratocystic odontogenic tumour. The maximum expression of AMFR was seen in ameloblastic carcinoma and minimum expression in multicystic ameloblastoma. Conclusion: The results of this study suggested an association of loss of expression of type IV Collagen with progression of lesion. AMFR expression was found to be associated with the aggressive potential of tumours. PMID:25478440

  20. Type IV carbonic anhydrase is present in the gills of spiny dogfish (Squalus acanthias).

    PubMed

    Gilmour, K M; Bayaa, M; Kenney, L; McNeill, B; Perry, S F

    2007-01-01

    Physiological and biochemical studies have provided indirect evidence for a membrane-associated carbonic anhydrase (CA) isoform, similar to mammalian type IV CA, in the gills of dogfish (Squalus acanthias). This CA isoform is linked to the plasma membrane of gill epithelial cells by a glycosylphosphatidylinositol anchor and oriented toward the plasma, such that it can catalyze the dehydration of plasma HCO(3)(-) ions. The present study directly tested the hypothesis that CA IV is present in dogfish gills in a location amenable to catalyzing plasma HCO(3)(-) dehydration. Homology cloning techniques were used to assemble a 1,127 base pair cDNA that coded for a deduced protein of 306 amino acids. Phylogenetic analysis suggested that this protein was a type IV CA. For purposes of comparison, a second cDNA (1,107 base pairs) was cloned from dogfish blood; it encoded a deduced protein of 260 amino acids that was identified as a cytosolic CA through phylogenetic analysis. Using real-time PCR and in situ hybridization, mRNA expression for the dogfish type IV CA was detected in gill tissue and specifically localized to pillar cells and branchial epithelial cells that flanked the pillar cells. Immunohistochemistry using a polyclonal antibody raised against rainbow trout type IV CA revealed a similar pattern of CA IV immunoreactivity and demonstrated a limited degree of colocalization with Na(+)-K(+)-ATPase immunoreactivity. The presence and localization of a type IV CA isoform in the gills of dogfish is consistent with the hypothesis that branchial membrane-bound CA with an extracellular orientation contributes to CO(2) excretion in dogfish by catalyzing the dehydration of plasma HCO(3)(-) ions.

  1. Serotype IV Sequence Type 468 Group B Streptococcus Neonatal Invasive Disease, Minnesota, USA

    PubMed Central

    Teatero, Sarah; Ferrieri, Patricia

    2016-01-01

    To further understand the emergence of serotype IV group B Streptococcus (GBS) invasive disease, we used whole-genome sequencing to characterize 3 sequence type 468 strains isolated from neonates in Minnesota, USA. We found that strains of tetracycline-resistant sequence type 468 GBS have acquired virulence genes from a putative clonal complex 17 GBS donor by recombination. PMID:27767922

  2. Oxyhydroxy Silicate Colloids: A New Type of Waterborne Actinide(IV) Colloids

    PubMed Central

    Weiss, Stephan; Hennig, Christoph; Brendler, Vinzenz; Ikeda‐Ohno, Atsushi

    2016-01-01

    Abstract At the near‐neutral and reducing aquatic conditions expected in undisturbed ore deposits or in closed nuclear waste repositories, the actinides Th, U, Np, and Pu are primarily tetravalent. These tetravalent actinides (AnIV) are sparingly soluble in aquatic systems and, hence, are often assumed to be immobile. However, AnIV could become mobile if they occur as colloids. This review focuses on a new type of AnIV colloids, oxyhydroxy silicate colloids. We herein discuss the chemical characteristics of these colloids and the potential implication for their environmental behavior. The binary oxyhydroxy silicate colloids of AnIV could be potentially more mobile as a waterborne species than the well‐known mono‐component oxyhydroxide colloids. PMID:27957406

  3. Thyroid follicular adenoma with accumulation of collagen type IV in a common marmoset (Callithrix jacchus).

    PubMed

    Kawasako, K; Doi, T; Kanno, T; Wako, Y; Hamamura, M; Tsuchitani, M

    2014-01-01

    A thyroid tumour was identified in a 10-year-old male common marmoset (Callithrix jacchus). The tumour was encapsulated by fibrous connective tissue and compressed the adjacent normal thyroid. The tumour was composed of variably sized and irregularly shaped thyroid follicles lined by a single layer of columnar epithelial cells. Eosinophilic material at the base of the neoplastic cells stained black with periodic acid-methenamine silver and red with periodic acid-Schiff. Immunohistochemistry confirmed that this eosinophilic material was collagen type IV. Ultrastructurally, highly dense and amorphous material was observed at the base of the neoplastic cells. Small vesicles in the basolateral cytoplasm of the neoplastic cells contained similar material to that at the base of the cells. The tumour was diagnosed as a thyroid follicular adenoma with accumulation of collagen type IV. This is the first description of an endocrine tumour with accumulation of collagen type IV in animals.

  4. Anaplasma phagocytophilum and Ehrlichia chaffeensis type IV secretion and Ank proteins

    PubMed Central

    RIKIHISA, YASUKO; LIN, MINGQUN

    2011-01-01

    Summary of recent advances The obligatory intracellular bacterial pathogens Anaplasma and Ehrlichia infect leukocytes by hijacking host-cell components and processes. The type IV secretion system is up-regulated during infection. Among type IV secretion candidate substrates, an ankyrin repeat protein of Anaplasma phagocytophilum, AnkA, is delivered into the host cytoplasm via a complex that includes VirD4. AnkA is highly tyrosine-phosphorylated and binds to the Abl interactor 1, SHP-1, and nuclear DNA fragments. Ehrlichia chaffeensis AnkA was recently reported to be translocated into host cell nucleus. The recent discovery of several ankyrin repeat proteins secreted via the type IV secretion system of different intracellular bacteria suggests that a common strategy evolved to subvert host-cell functions. PMID:20053580

  5. Spontaneous Carotid-Cavernous Fistula in the Type IV Ehlers-Danlos Syndrome.

    PubMed

    Kim, Jeong Gyun; Cho, Won-Sang; Kang, Hyun-Seung; Kim, Jeong Eun

    2014-02-01

    Ehlers-Danlos syndrome (EDS) is a rare inherited connective disease. Among several subgroups, type IV EDS is frequently associated with spontaneous catastrophic bleeding from a vascular fragility. We report on a case of carotid-cavernous fistula (CCF) in a patient with type IV EDS. A 46-year-old female presented with an ophthalmoplegia and chemosis in the right eye. Subsequently, seizure and cerebral infarction with micro-bleeds occurred. CCF was completely occluded with transvenous coil embolization without complications. Thereafter, the patient was completely recovered. Transvenous coil embolization can be a good treatment of choice for spontaneous CCF with type IV EDS. However, every caution should be kept during invasive procedure.

  6. Spontaneous Carotid-Cavernous Fistula in the Type IV Ehlers-Danlos Syndrome

    PubMed Central

    Kim, Jeong Gyun; Cho, Won-Sang; Kim, Jeong Eun

    2014-01-01

    Ehlers-Danlos syndrome (EDS) is a rare inherited connective disease. Among several subgroups, type IV EDS is frequently associated with spontaneous catastrophic bleeding from a vascular fragility. We report on a case of carotid-cavernous fistula (CCF) in a patient with type IV EDS. A 46-year-old female presented with an ophthalmoplegia and chemosis in the right eye. Subsequently, seizure and cerebral infarction with micro-bleeds occurred. CCF was completely occluded with transvenous coil embolization without complications. Thereafter, the patient was completely recovered. Transvenous coil embolization can be a good treatment of choice for spontaneous CCF with type IV EDS. However, every caution should be kept during invasive procedure. PMID:24653803

  7. Clinical presentation and outcomes in type IV dual left anterior descending artery anomaly

    PubMed Central

    Çanga, Yiğit; Güvenç, Tolga Sinan; Karataş, Mehmet Baran; Güngör, Bariş; Çetin, Rengin; Bolca, Osman

    2016-01-01

    Type IV dual left anterior descending artery (LAD) anomaly constitutes a rare subset of coronary anomalies in which the anterior and anterolateral wall of the left ventricle is supplied by a short LAD originating from the left coronary artery along with a long LAD that originates from the right sinus of Valsalva. Albeit rare, the angiographic presentation is challenging since the appearance of the short LAD is similar to a total occlusion beyond first few diagonal or septal branches. Here, we present a series of four cases with type IV dual LAD anomaly with different clinical and angiographic presentations. PMID:28250981

  8. Different assembly of type IV collagen on hydrophilic and hydrophobic substrata alters endothelial cells interaction.

    PubMed

    Coelho, N Miranda; González-García, C; Planell, J A; Salmerón-Sánchez, M; Altankov, G

    2010-06-09

    Considering the structural role of type IV collagen (Col IV) in the assembly of the basement membrane (BM) and the perspective of mimicking its organization for vascular tissue engineering purposes, we studied the adsorption pattern of this protein on model hydrophilic (clean glass) and hydrophobic trichloro(octadecyl)silane (ODS) surfaces known to strongly affect the behavior of other matrix proteins. The amount of fluorescently labeled Col IV was quantified showing saturation of the surface for concentration of the adsorbing solution of about 50microg/ml, but with approximately twice more adsorbed protein on ODS. AFM studies revealed a fine - nearly single molecular size - network arrangement of Col IV on hydrophilic glass, which turns into a prominent and growing polygonal network consisting of molecular aggregates on hydrophobic ODS. The protein layer forms within minutes in a concentration-dependent manner. We further found that human umbilical vein endothelial cells (HUVEC) attach less efficiently to the aggregated Col IV (on ODS), as judged by the significantly altered cell spreading, focal adhesions formation and the development of actin cytoskeleton. Conversely, the immunofluorescence studies for integrins revealed that the fine Col IV network formed on hydrophilic substrata is better recognized by the cells via both alpha1 and alpha2 heterodimers which support cellular interaction, apart from these on hydrophobic ODS where almost no clustering of integrins was observed.

  9. Dipeptidyl peptidase IV inhibitors: a promising new therapeutic approach for the management of type 2 diabetes.

    PubMed

    Deacon, Carolyn F; Holst, Jens J

    2006-01-01

    Glucagon-like peptide-1 is an insulinotropic hormone with antidiabetic potential due to its spectrum of effects, which include glucose-dependent stimulation of insulin and inhibition of glucagon secretion, tropic effects on the pancreatic beta-cells, inhibition of gastric emptying and the reduction of appetite. Glucagon-like peptide-1 is, however, extremely rapidly inactivated by the serine peptidase, dipeptidyl peptidase IV, so that the native peptide is not useful clinically. A new approach to utilise the beneficial effects of glucagon-like peptide-1 in the treatment of type 2 diabetes has been the development of orally active dipeptidyl peptidase IV inhibitors. Preclinical studies have demonstrated that this approach is effective in enhancing endogenous levels of glucagon-like peptide-1, resulting in improved glucose tolerance in glucose-intolerant and diabetic animal models. In recent studies of 3-12 months duration in patients with type 2 diabetes, dipeptidyl peptidase IV inhibitors have proved efficacious, both as monotherapy and when given in combination with metformin. Fasting and postprandial glucose concentrations were reduced, leading to reductions in glycosylated haemoglobin levels, while beta-cell function was preserved. Current information suggests dipeptidyl peptidase IV inhibitors are body weight neutral and are well tolerated. A number of dipeptidyl peptidase IV inhibitors are now in the late stages of clinical development. These have different properties, in terms of their duration of action and anticipated dosing frequency, but data from protracted dosing studies is presently not available to allow comparison of their clinical efficacy.

  10. Soft tissue reconstruction for type IV-D duplicated thumb: a new surgical technique.

    PubMed

    Tien, Yin-Chun; Chih, Tsai-Tung; Wang, Tai-Lung; Fu, Yin-Chih; Chen, Jian-Chih

    2007-06-01

    Type IV-D duplicated thumb has the most complex anomalies and difficulties for treatment among polydatyly. Double osteotomy is usually recommended to gain the best cosmetic and functional outcome. However, 4 cases of type IV-D duplicated thumb were treated only by soft tissue procedure in this study. At operation, a conjoined A2 pulley was routinely identified, and the flexor pollicis longus (FPL) was found bifurcated distal to the conjoined pulley in every of these cases. Instead of double osteotomy, a soft tissue procedure that included centralization of FPL and A2 pulley reconstruction was pursued to correct these special anomalies. The overall clinical results were evaluated by a modification of the Tada scoring system based on the range of motion, joint stability, alignment of the remaining thumb, and subjective opinion regarding the reconstructed thumb after an average follow-up of 3.3 years (range, 2.5-4.7 years). According to the scoring system, the results were rated as good in 3 cases and fair in 1 case. From the results, the A2 pulley reconstruction and FPL centralization could prove to be an effective method for the treatment of type IV-D duplicated thumb and could efficiently avoid the residual angular deformities. Therefore, we recommend this soft tissue procedure as an alternative surgical technique to the double-osteotomy procedure for treating a type IV-D duplicated thumb in a very young child, whose bone is still not mature enough for holding the fixing pins.

  11. Examination of type IV pilus expression and pilus-associated phenotypes in Kingella kingae clinical isolates.

    PubMed

    Kehl-Fie, Thomas E; Porsch, Eric A; Yagupsky, Pablo; Grass, Elizabeth A; Obert, Caroline; Benjamin, Daniel K; St Geme, Joseph W

    2010-04-01

    Kingella kingae is a gram-negative bacterium that is being recognized increasingly as a cause of septic arthritis and osteomyelitis in young children. Previous work established that K. kingae expresses type IV pili that mediate adherence to respiratory epithelial and synovial cells. PilA1 is the major pilus subunit in K. kingae type IV pili and is essential for pilus assembly. To develop a better understanding of the role of K. kingae type IV pili during colonization and invasive disease, we examined a collection of clinical isolates for pilus expression and in vitro adherence. In addition, in a subset of isolates we performed nucleotide sequencing to assess the level of conservation of PilA1. The majority of respiratory and nonendocarditis blood isolates were piliated, while the majority of joint fluid, bone, and endocarditis blood isolates were nonpiliated. The piliated isolates formed either spreading/corroding or nonspreading/noncorroding colonies and were uniformly adherent, while the nonpiliated isolates formed domed colonies and were nonadherent. PilA1 sequence varied significantly from strain to strain, resulting in substantial variability in antibody reactivity. These results suggest that type IV pili may confer a selective advantage on K. kingae early in infection and a selective disadvantage on K. kingae at later stages in the pathogenic process. We speculate that PilA1 is immunogenic during natural infection and undergoes antigenic variation to escape the immune response.

  12. Examination of Type IV Pilus Expression and Pilus-Associated Phenotypes in Kingella kingae Clinical Isolates▿

    PubMed Central

    Kehl-Fie, Thomas E.; Porsch, Eric A.; Yagupsky, Pablo; Grass, Elizabeth A.; Obert, Caroline; Benjamin, Daniel K.; St. Geme, Joseph W.

    2010-01-01

    Kingella kingae is a gram-negative bacterium that is being recognized increasingly as a cause of septic arthritis and osteomyelitis in young children. Previous work established that K. kingae expresses type IV pili that mediate adherence to respiratory epithelial and synovial cells. PilA1 is the major pilus subunit in K. kingae type IV pili and is essential for pilus assembly. To develop a better understanding of the role of K. kingae type IV pili during colonization and invasive disease, we examined a collection of clinical isolates for pilus expression and in vitro adherence. In addition, in a subset of isolates we performed nucleotide sequencing to assess the level of conservation of PilA1. The majority of respiratory and nonendocarditis blood isolates were piliated, while the majority of joint fluid, bone, and endocarditis blood isolates were nonpiliated. The piliated isolates formed either spreading/corroding or nonspreading/noncorroding colonies and were uniformly adherent, while the nonpiliated isolates formed domed colonies and were nonadherent. PilA1 sequence varied significantly from strain to strain, resulting in substantial variability in antibody reactivity. These results suggest that type IV pili may confer a selective advantage on K. kingae early in infection and a selective disadvantage on K. kingae at later stages in the pathogenic process. We speculate that PilA1 is immunogenic during natural infection and undergoes antigenic variation to escape the immune response. PMID:20145101

  13. Campylobacter fetus subspecies contain conserved type IV secretion systems on multiple genomic islands and plasmids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The features contributing to the differences in pathogenicity of the C. fetus subspecies are unknown. Putative factors involved in pathogenesis are located in genomic islands that encode type IV secretion system (T4SS) and fic-domain (filamentation induced by cyclic AMP) proteins. In the genomes of ...

  14. Type IV renal tubular acidosis and spironolactone therapy in the elderly.

    PubMed Central

    O'Connell, J. E.; Colledge, N. R.

    1993-01-01

    Spironolactone therapy is a well-known cause of hyperkalaemia, but in susceptible patient, it may also be associated with metabolic acidosis. We report a case of severe renal tubular acidosis (Type IV) with life-threatening hyperkalaemia caused by spironolactone, and discuss the mechanisms by which this may occur. PMID:8290440

  15. [Type 1 Arnold Chiari malformation, syringomielia, syringobulbia and IV ventricle entrapment].

    PubMed

    Carrillo-Esper, Raúl; Vázquez-Elizondo, Genaro; Gutiérrez-Delgado, Linda G; Guevara-Arnal, Luis; Méndez-Sánchez, Nahum

    2008-01-01

    Arnold-Chiari Malformation (ACM) was first described by Hans Chiari in 1890. Four types of this malformation are recognized, of those, type I is the most common among adults. It is caused by an elongation of the cerebellum into the conic projections that accompany the brain stem within the spinal channel. It is mostly congenital but "acquired" forms can be seen in the context of infections or posterior fossa tumors. Clinically, it can present as an asymptomatic finding, but it can produce brain stem compression. Syringomielia--cavitation of the brain stem central areas--is associated with MAC type I in 75 to 85% of cases. Clinical signs include pain, weakness, extremity parestesia. A shunt to the lateral ventricles can produce IV ventricle entrapment and is associated with cerebrospinal fluid blockage. We describe a case of MAC type I associated with the presence of syringomielia, syringobulbia and IV ventricle entrapment.

  16. Immunocytochemical traits of type IV fibrocytes and their possible relations to cochlear function and pathology.

    PubMed

    Adams, Joe C

    2009-09-01

    One of the more consistent and least understood changes in the aging human cochlea is the progressive loss of fibrocytes within the spiral ligament. This report presents an animal model for type IV fibrocyte loss, along with immunocytochemical evidence that noise-induced loss of these cells may account for previously unexplained hearing losses. The remarkably low threshold for noise-induced loss of type IV fibrocytes, approximately 24 dB less than the threshold for adjacent hair cell destruction, may account for the prevalence of missing fibrocytes in humans. In mice, changes in the spectrum of traumatizing noise had little effect upon the site of loss of the fibrocytes, suggesting that the primary site of damage that induced the loss was the basal-most cochlear turn, a site expected to be damaged by all three noise bands. Type IV fibrocytes were found to immunostain for connective tissue growth factor (CTGF) and for transforming growth factor beta receptor 3, a receptor that is known to activate CTGF expression. Type IV fibrocytes lack immunostaining for adenosine triphosphatase and connexins that are key players in potassium ion uptake and transmission, which suggests that they play little, if any, role in potassium recycling from perilymphatic space to the endolymphatic space. Consequently, their loss probably does not directly reduce this process. Immunostaining for a receptor for CTGF, low-density-lipoprotein-related protein 1, indicated that CTGF acts as an autocrine and a paracrine agent within the cochlea. The lack of CTGF paracrine effects following noise-induced loss of type IV fibrocytes may account for previously unexplained hearing losses.

  17. Twins with hereditary sensory and autonomic neuropathy type IV with preserved periodontal sensation.

    PubMed

    Guven, Yeliz; Altunoglu, Umut; Aktoren, Oya; Uyguner, Zehra Oya; Kayserili, Hulya; Kaewkahya, Massupa; Kantaputra, Piranit Nik

    2014-04-01

    Turkish twin brothers affected with hereditary sensory and autonomic neuropathy type IV (HSAN IV) are reported. Their clinical findings were generally typical for HSAN IV. Interestingly they both had preserved periodontal sensation. Mutation analysis of the NTRK1 gene showed a homozygous c.2001C>T substitution in exon 15 in both twins. This base substitution is predicted to change a polar, positively charged amino acid arginine to the highly active amino acid cystein at position 654 (p.Arg654Cys). The parents were heterozygous for the mutation. This mutation has been reported previously in one Japanese and one Arab patients. The preserved periodontal sensation has not previously been reported in patients affected with HSAN IV. This preserved sensation in our patients might have been through Ruffini endings, the periodontal mechanoreceptors which have been reported to be present in TrkA knockout mice. Here we report the first twins affected with HSAN IV and the observation that periodontal sensation is not affected by mutation in NTRK1.

  18. A type IV osteogenesis imperfecta family and pregnancy: a case report and literature review.

    PubMed

    Feng, Zhao-yi; Chen, Qian; Shi, Chun-yan; Wen, Hong-wu; Ma, Ke; Yang, Hui-xia

    2012-04-01

    Osteogenesis imperfecta is a group of inherited connective-tissue disorders in which synthesis or structure of type I collagen is defective and causes osseous fragility. Type IV osteogenesis imperfecta is dominant inheritance. Here, we report a case of type IV osteogenesis imperfecta family and their female member's pregnancy. Abnormal sonographic findings (marked bowing and shortening of long bones) and family history made the diagnosis of fetus with osteogenesis imperfecta. The parents decided to give up rescuing the infant and a caesarean section at 27 weeks of gestation was implemented. In conclusion, it is possible to make a prenatal diagnosis of osteogenesis imperfecta by ultrasound. For the pregnant women with osteogenesis imperfecta, management decision should be made on an individual basis.

  19. Lipocytes from normal rat liver release a neutral metalloproteinase that degrades basement membrane (type IV) collagen.

    PubMed Central

    Arthur, M J; Friedman, S L; Roll, F J; Bissell, D M

    1989-01-01

    We report a proteinase that degrades basement-membrane (type IV) collagen and is produced by the liver. Its cellular source is lipocytes (fat-storing or Ito cells). Lipocytes were isolated from normal rat liver and established in primary culture. The cells synthesize and secrete a neutral proteinase, which by gelatin-substrate gel electrophoresis and gel filtration chromatography, has a molecular mass of 65,000 D. The enzyme is secreted in latent form and is activated by p-aminophenylmercuric acetate but not by trypsin. Enzyme activity in the presence of EDTA is restored selectively by zinc and is unaffected by serine-protease inhibitors. In assays with radiolabeled soluble substrates, it degrades native type IV (basement membrane) collagen but not interstitial collagen types I or V and exhibits no activity against laminin or casein. At temperatures causing partial denaturation of soluble collagen in vitro, it rapidly degrades types I and V. Thus, it is both a type IV collagenase and gelatinase. The enzyme may play a role in initiating breakdown of the subendothelial matrix in the Disse space as well as augmenting the effects of collagenases that attack native interstitial collagen. Images PMID:2551922

  20. Duck Hepatitis A virus possesses a distinct type IV internal ribosome entry site element of picornavirus.

    PubMed

    Pan, Meng; Yang, Xiaorong; Zhou, Lei; Ge, Xinna; Guo, Xin; Liu, Jinhua; Zhang, Dabing; Yang, Hanchun

    2012-01-01

    Sequence analysis of duck hepatitis virus type 1 (DHV-1) led to its classification as the only member of a new genus, Avihepatovirus, of the family Picornaviridae, and so was renamed duck hepatitis A virus (DHAV). The 5' untranslated region (5' UTR) plays an important role in translation initiation and RNA synthesis of the picornavirus. Here, we provide evidence that the 651-nucleotide (nt)-long 5' UTR of DHAV genome contains an internal ribosome entry site (IRES) element that functions efficiently in vitro and within BHK cells. Comparative sequence analysis showed that the 3' part of the DHAV 5' UTR is similar to the porcine teschovirus 1 (PTV-1) IRES in sequence and predicted secondary structure. Further mutational analyses of the predicted domain IIId, domain IIIe, and pseudoknot structure at the 3' end of the DHAV IRES support our predicted secondary structure. However, unlike the case for the PTV-1 IRES element, analysis of various deletion mutants demonstrated that the optimally functional DHAV IRES element with a size of approximately 420 nt is larger than that of PTV-1 and contains other peripheral domains (Id and Ie) that do not exist within the type IV IRES elements. The domain Ie, however, could be removed without significant loss of activity. Surprisingly, like the hepatitis A virus (HAV) IRES element, the activity of DHAV IRES could be eliminated by expression of enterovirus 2A protease. These findings indicate that the DHAV IRES shares common features with type IV picornavirus IRES elements, whereas it exhibits significant differences from type IV IRESs. Therefore, we propose that DHAV possesses a distinct type IV IRES element of picornavirus.

  1. Renal tubular acidosis type IV as a complication of lupus nephritis.

    PubMed

    Sánchez-Marcos, C; Hoffman, V; Prieto-González, S; Hernández-Rodríguez, J; Espinosa, G

    2016-03-01

    Renal tubular acidosis (RTA) is a rare complication of renal involvement of systemic lupus erythematosus (SLE). We describe a 24-year-old male with type IV lupus nephropathy as a presenting manifestation of SLE. He presented with improvement of renal function following induction therapy with three pulses of methylprednisolone and 500 mg biweekly pulses of cyclophosphamide. However, a week after the first pulse of cyclophosphamide, the patient presented with a significant increase in legs edema and severe hyperkalemia. Type IV RTA associated with hyporeninemic hypoaldosteronism was suspected in the presence of metabolic acidosis with a normal anion gap, severe hyperkalemia without worsening renal function, and urinary pH of 5. RTA was confirmed with a transtubular potassium concentration gradient of 2 and low levels of plasma aldosterone, renin, angiotensin II, and cortisol. Intravenous bicarbonate, high-dose furosemide, and fludrocortisone were administered with normalization of potassium levels and renal function.

  2. Type IV Sacrococcygeal Teratoma Displacing the Urinary Bladder: Unique Magnetic Resonance Imaging

    PubMed Central

    Eftekharzadeh, Sahar; Keihani, Sorena; Fareghi, Mehdi; Alamsahebpour, Alireza; Kajbafzadeh, Abdol-Mohammad

    2016-01-01

    Type IV sacrococcygeal teratoma is a rare pediatric tumor that is confined to the presacral area with no external component. The signs and symptoms often arise due to mass effect and compression of adjacent organs. Urinary retention is an uncommon presenting symptom in these patients. A wide spectrum of imaging findings may be encountered in cases with sacrococcygeal teratoma because of variability of tumor size and components. We hereby present a unique magnetic resonance urography finding in a type IV sacrococcygeal teratoma which caused bladder displacement. A meticulous and complete resection of tumor with special attention to the pelvic plexus led to preservation of normal voiding function and normal bowel function in this patient. PMID:27413571

  3. Irradiation Alters MMP-2/TIMP-2 System and Collagen Type IV Degradation in Brain

    SciTech Connect

    Lee, Won Hee; Warrington, Junie P.; Sonntag, William E.; Lee, Yong Woo

    2012-04-01

    Purpose: Blood-brain barrier (BBB) disruption is one of the major consequences of radiation-induced normal tissue injury in the central nervous system. We examined the effects of whole-brain irradiation on matrix metalloproteinases (MMPs)/tissue inhibitors of metalloproteinases (TIMPs) and extracellular matrix (ECM) degradation in the brain. Methods and Materials: Animals received either whole-brain irradiation (a single dose of 10 Gy {gamma}-rays or a fractionated dose of 40 Gy {gamma}-rays, total) or sham-irradiation and were maintained for 4, 8, and 24 h following irradiation. mRNA expression levels of MMPs and TIMPs in the brain were analyzed by real-time reverse transcriptase-polymerase chain reaction (PCR). The functional activity of MMPs was measured by in situ zymography, and degradation of ECM was visualized by collagen type IV immunofluorescent staining. Results: A significant increase in mRNA expression levels of MMP-2, MMP-9, and TIMP-1 was observed in irradiated brains compared to that in sham-irradiated controls. In situ zymography revealed a strong gelatinolytic activity in the brain 24 h postirradiation, and the enhanced gelatinolytic activity mediated by irradiation was significantly attenuated in the presence of anti-MMP-2 antibody. A significant reduction in collagen type IV immunoreactivity was also detected in the brain at 24 h after irradiation. In contrast, the levels of collagen type IV were not significantly changed at 4 and 8 h after irradiation compared with the sham-irradiated controls. Conclusions: The present study demonstrates for the first time that radiation induces an imbalance between MMP-2 and TIMP-2 levels and suggests that degradation of collagen type IV, a major ECM component of BBB basement membrane, may have a role in the pathogenesis of brain injury.

  4. Effects of type IV collagen on myogenic characteristics of IGF-I gene-engineered myoblasts.

    PubMed

    Ito, Akira; Yamamoto, Masahiro; Ikeda, Kazushi; Sato, Masanori; Kawabe, Yoshinori; Kamihira, Masamichi

    2015-05-01

    Skeletal muscle regeneration requires migration, proliferation and fusion of myoblasts to form multinucleated myotubes. In our previous study, we showed that insulin-like growth factor (IGF)-I gene delivery stimulates the proliferation and differentiation of mouse myoblast C2C12 cells and promotes the contractile force generated by tissue-engineered skeletal muscles. The aim of this study was to investigate the effects of the extracellular matrix on IGF-I gene-engineered C2C12 cells in vitro. Retroviral vectors for doxycycline (Dox)-inducible expression of the IGF-I gene were transduced into C2C12 cells. When cultured on a type IV collagen-coated surface, we observed significant increases in the migration speed and number of IGF-I gene-engineered C2C12 cells with Dox addition, designated as C2C12/IGF (+) cells. Co-culture of C2C12/IGF (+) cells and parental C2C12 cells, which had been cultured in differentiation medium for 3 days, greatly enhanced myotube formation. Moreover, type IV collagen supplementation promoted the fusion of C2C12/IGF (+) cells with differentiated C2C12 cells and increased the number of myotubes with striations. Myotubes formed by C2C12/IGF (+) cells cultured on type IV collagen showed a dynamic contractile activity in response to electrical pulse stimulation. These findings indicate that type IV collagen promotes skeletal muscle regeneration mediated by IGF-I-expressing myoblasts, which may have important clinical implications in the design of myoblast-based therapies.

  5. Effects of monocyte-endothelium interactions on the expression of type IV collagenases in monocytes

    PubMed Central

    LI, YONG-QIN; LIU, RUI; XUE, JIA-HONG; ZHANG, YAN; GAO, DENG-FENG; WU, XIAO-SAN; WANG, CONG-XIA; YANG, YU-BAI

    2015-01-01

    The adhesion of monocytes to endothelial cells is one of the early stages in the development of atherosclerosis. The expression of type IV collagenases, which include matrix metalloproteinase (MMP)-2 and MMP-9, in monocytes is hypothesized to play an important role in monocyte infiltration and transformation into foam cells. The aim of the present study was to examine the effects of monocyte-endothelium interactions on the expression levels of type IV collagenases and their specific inhibitors in monocytes, and to investigate the roles of tumor necrosis factor (TNF)-α and interleukin (IL)-1β in this process. Monocytes were single-cultured or co-cultured with endothelial cells. The expression of the type IV collagenases, MMP-2 and MMP-9, and their specific inhibitors, tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2, in monocytes was determined by immunohistochemistry followed by image analysis. The expression levels of MMP-2 and MMP-9 were found to be low in the single-culture monocytes, but increased significantly when the monocytes and endothelial cells were co-cultured. However, treatment with monoclonal TNF-α or IL-1β antibodies partially inhibited the upregulated expression of MMP-2 and MMP-9 in the co-cultured monocytes. Expression of TIMP-1 and TIMP-2 was observed in the single monocyte culture, and a small increase in the expression levels was observed when the monocytes were co-cultured with endothelial cells. Therefore, monocyte-endothlium interactions were shown to increase the expression of type IV collagenases in monocytes, resulting in the loss of balance between MMP-2 and -9 with TIMP-1 and -2. In addition, TNF-α and IL-1β were demonstrated to play important roles in this process. PMID:25574228

  6. Endodontic Treatment of a Maxillary First Premolar with Type IV Buccal Root Canal: A Case Report

    PubMed Central

    Dadresanfar, Bahareh; Khalilak, Zohreh; Shahmirzadi, Solaleh

    2009-01-01

    The maxillary first premolar may present large number of anatomic variations. The clinician should be aware of the configuration of the pulp system. Maxillary first premolars usually have two canals. The incidence of three canals in these teeth is quite rare. This case report presents the diagnosis and clinical management of a maxillary first premolar with two distinct canals in the apical third of buccal root (type IV), drawing particular attention to tactile examination of all the canal walls. PMID:23864875

  7. Type IV secretion systems: tools of bacterial horizontal gene transfer and virulence

    PubMed Central

    Juhas, Mario; Crook, Derrick W; Hood, Derek W

    2008-01-01

    Type IV secretion systems (T4SSs) are multisubunit cell-envelope-spanning structures, ancestrally related to bacterial conjugation machines, which transfer proteins and nucleoprotein complexes across membranes. T4SSs mediate horizontal gene transfer, thus contributing to genome plasticity and the evolution of pathogens through dissemination of antibiotic resistance and virulence genes. Moreover, T4SSs are also used for the delivery of bacterial effector proteins across the bacterial membrane and the plasmatic membrane of eukaryotic host cell, thus contributing directly to pathogenicity. T4SSs are usually encoded by multiple genes organized into a single functional unit. Based on a number of features, the organization of genetic determinants, shared homologies and evolutionary relationships, T4SSs have been divided into several groups. Type F and P (type IVA) T4SSs resembling the archetypal VirB/VirD4 system of Agrobacterium tumefaciens are considered to be the paradigm of type IV secretion, while type I (type IVB) T4SSs are found in intracellular bacterial pathogens, Legionella pneumophila and Coxiella burnetii. Several novel T4SSs have been identified recently and their functions await investigation. The most recently described GI type T4SSs play a key role in the horizontal transfer of a wide variety of genomic islands derived from a broad spectrum of bacterial strains. PMID:18549454

  8. Structural and dynamic properties of bacterial Type IV secretion systems (Review)

    PubMed Central

    Christie, Peter J.; Cascales, Eric

    2014-01-01

    The type IV secretion systems (T4SS) are widely distributed among the Gram-negative and –positive bacteria. These systems mediate the transfer of DNA and protein substrates across the cell envelope to bacterial or eukaryotic cells generally through a process requiring direct cell-to-cell contact. Bacteria have evolved T4SS for survival during establishment of pathogenic or symbiotic relationships with eukaryotic hosts. The Agrobacterium tumefaciens VirB/D4 T4SS and related conjugation machines serve as models for detailed mechanistic studies aimed at elucidating the nature of translocation signals, machine assembly pathways and architectures, and the dynamics of substrate translocation. The A. tumefaciens VirB/D4 T4SS are polar-localized organelles composed of a secretion channel and an extracellular T pilus. These T4SS are assembled from 11 or more subunits. whose membrane topologies, intersubunit contacts and, in some cases, 3-dimensional structures are known. Recently, powerful in vivo assays have identified C-terminal translocation signals, defined for the first time the translocation route for a DNA substrate through a type IV secretion channel, and supplied evidence that ATP energy consumption contributes to a late stage of machine morphogenesis. Together, these recent findings describe the mechanics of type IV secretion in unprecedented detail. PMID:16092524

  9. Microstructures and Type-IV Creep Damage of High Cr Steel Welds

    NASA Astrophysics Data System (ADS)

    Hongo, Hiromichi; Tabuchi, Masaaki; Takahashi, Yukio

    Creep strength of welded joints in high Cr steels decreases due to the formation of Type-IV creep damage in the heat-affected zone (HAZ) during long-term use at high temperatures. This paper aims to elucidate the processes and mechanisms of Type-IV failure. Creep tests for the welded joints with different groove configurations of Mod.9Cr-1Mo steel were conducted. Distributions of Type-IV creep damages in HAZ of these welds were measured quantitatively, and were compared with FEM computations using damage mechanics analysis. For the welded joints with double U groove, creep voids were observed mostly at 20% below the surface of the plate, and scarcely near surfaces and center of thickness. For the welded joints with single U groove, creep voids were observed inside the plate thickness more than 3mm below the surfaces. From the comparison of experimental damage distributions with FEM analysis, it is considered to be important to take the stress triaxiality into account for the prediction of damage location and fracture life of high Cr ferritic steel welds.

  10. Structure and function of the adhesive type IV pilus of Sulfolobus acidocaldarius.

    PubMed

    Henche, Anna-Lena; Ghosh, Abhrajyoti; Yu, Xiong; Jeske, Torsten; Egelman, Edward; Albers, Sonja-Verena

    2012-12-01

    Archaea display a variety of type IV pili on their surface and employ them in different physiological functions. In the crenarchaeon Sulfolobus acidocaldarius the most abundant surface structure is the aap pilus (archaeal adhesive pilus). The construction of in frame deletions of the aap genes revealed that all the five genes (aapA, aapX, aapE, aapF, aapB) are indispensible for assembly of the pilus and an impact on surface motility and biofilm formation was observed. Our analyses revealed that there exists a regulatory cross-talk between the expression of aap genes and archaella (formerly archaeal flagella) genes during different growth phases. The structure of the aap pilus is entirely different from the known bacterial type IV pili as well as other archaeal type IV pili. An aap pilus displayed 3 stranded helices where there is a rotation per subunit of ∼138° and a rise per subunit of ∼5.7 Å. The filaments have a diameter of ∼110 Å and the resolution was judged to be ∼9 Å. We concluded that small changes in sequence might be amplified by large changes in higher-order packing. Our finding of an extraordinary stability of aap pili possibly represents an adaptation to harsh environments that S. acidocaldarius encounters.

  11. Laminin and type IV collagen isoform substitutions occur in temporally and spatially distinct patterns in developing kidney glomerular basement membranes.

    PubMed

    Abrahamson, Dale R; St John, Patricia L; Stroganova, Larysa; Zelenchuk, Adrian; Steenhard, Brooke M

    2013-10-01

    Kidney glomerular basement membranes (GBMs) undergo laminin and type IV collagen isoform substitutions during glomerular development, which are believed to be required for maturation of the filtration barrier. Specifically, GBMs of earliest glomeruli contain laminin α1β1γ1 and collagen α1α2α1(IV), whereas mature glomeruli contain laminin α5β2γ1 and collagen α3α4α5(IV). Here, we used confocal microscopy to simultaneously evaluate expression of different laminin and collagen IV isoforms in newborn mouse GBMs. Our results show loss of laminin α1 from GBMs in early capillary loop stages and continuous linear deposition of laminin bearing the α5 chain thereafter. In contrast, collagen α1α2α1(IV) persisted in linear patterns into late capillary loop stages, when collagen α3α4α5(IV) first appeared in discontinuous, non-linear patterns. This patchy pattern for collagen α3α4α5(IV) continued into maturing glomeruli where there were lengths of linear, laminin α5-positive GBM entirely lacking either isoform of collagen IV. Relative abundance of laminin and collagen IV mRNAs in newborn and 5-week-old mouse kidneys also differed, with those encoding laminin α1, α5, β1, β2, and γ1, and collagen α1(IV) and α2(IV) chains all significantly declining at 5 weeks, but α3(IV) and α4(IV) were significantly upregulated. We conclude that different biosynthetic mechanisms control laminin and type IV collagen expression in developing glomeruli.

  12. Implementation of GLP-1 based therapy of type 2 diabetes mellitus using DPP-IV inhibitors.

    PubMed

    Holst, Jens Juul

    2003-01-01

    GLP-1 is a peptide hormone from the intestinal mucosa. It is secreted in response to meal ingestion and normally functions in the so-called ileal brake i. e. inhibition of upper gastrointestinal motility and secretion when nutrients are present in the distal small intestine. It also induces satiety and promotes tissue deposition of ingested glucose by stimulating insulin secretion. Thus, it is an essential incretin hormone. In addition, the hormone has been demonstrated to promote insulin biosynthesis and insulin gene expression and to have trophic effects on the beta cells. The trophic effects include proliferation of existing beta cells, maturation of new cells from duct progenitor cells and inhibition of apoptosis. Furthermore glucagon secretion is inhibited. Because of these effects, the hormone effectively improves metabolism in patients with type 2 diabetes mellitus. However, continuous administration of the peptide is necessary because of an exceptionally rapid rate of degradation catalyzed the enzyme dipeptidyl peptidase IV. With inhibitors of this enzyme, it is possible to protect the endogenous hormone and thereby elevate both fasting and postprandial levels of the active hormone. This leads to enhanced insulin secretion and glucose turnover. But will DPP-IV inhibition enhance all effects of the endogenous peptide? The mode of action of GLP-1 is complex involving also interactions with sensory neurons and the central nervous system, where a DPP-IV mediated degradation does not seem to occur. Therefore, it is as yet uncertain wether DDP-IV inhibitors will affect gastrointestinal motility, appetite and food intake. Even the effects of GLP-1 effects on the pancreatic islets may be partly neurally mediated and therefore uninfluenced by DPP-IV inhibition.

  13. Endovascular Treatment of a Carotid Dissecting Pseudoaneurysm in a Patient with Ehlers-Danlos Syndrome Type IV with Fatal Outcome

    SciTech Connect

    Lim, Siok Ping Duddy, Martin J.

    2008-01-15

    We present a patient with Ehlers-Danlos syndrome type IV (EDS IV) with a carotid dissecting pseudoaneurysm causing severe carotid stenosis. This lesion was treated endovascularly. Unfortunately, the patient died of remote vascular catastrophes (intracranial hemorrhage and abdominal aortic rupture). This unique case illustrates the perils of endovascular treatment of EDS IV patients and the need for preoperative screening for concomitant lesions. It also shows that a dissecting pseudoaneurysm can feasibly be treated with a covered stent and that closure is effective using Angioseal in patients with EDS IV.

  14. Kingella kingae expresses type IV pili that mediate adherence to respiratory epithelial and synovial cells.

    PubMed

    Kehl-Fie, Thomas E; Miller, Sara E; St Geme, Joseph W

    2008-11-01

    Kingella kingae is a gram-negative bacterium that colonizes the respiratory tract and is a common cause of septic arthritis and osteomyelitis. Despite the increasing frequency of K. kingae disease, little is known about the mechanism by which this organism adheres to respiratory epithelium and seeds joints and bones. Previous work showed that K. kingae expresses long surface fibers that vary in surface density. In the current study, we found that these fibers are type IV pili and are necessary for efficient adherence to respiratory epithelial and synovial cells and that the number of pili expressed by the bacterium correlates with the level of adherence to synovial cells but not with the level of adherence to respiratory cells. In addition, we established that the major pilin subunit is encoded by a pilA homolog in a conserved region of the chromosome that also contains a second pilin gene and a type IV pilus accessory gene, both of which are dispensable for pilus assembly and pilus-mediated adherence. Upon examination of the K. kingae genome, we identified two genes in physically separate locations on the chromosome that encode homologs of the Neisseria PilC proteins and that have only a low level homology to each other. Examination of mutant strains revealed that both of the K. kingae PilC homologs are essential for a wild-type level of adherence to both respiratory epithelial and synovial cells. Taken together, these results demonstrate that type IV pili and the two PilC homologs play important roles in mediating K. kingae adherence.

  15. Kingella kingae Expresses Type IV Pili That Mediate Adherence to Respiratory Epithelial and Synovial Cells▿

    PubMed Central

    Kehl-Fie, Thomas E.; Miller, Sara E.; St. Geme, Joseph W.

    2008-01-01

    Kingella kingae is a gram-negative bacterium that colonizes the respiratory tract and is a common cause of septic arthritis and osteomyelitis. Despite the increasing frequency of K. kingae disease, little is known about the mechanism by which this organism adheres to respiratory epithelium and seeds joints and bones. Previous work showed that K. kingae expresses long surface fibers that vary in surface density. In the current study, we found that these fibers are type IV pili and are necessary for efficient adherence to respiratory epithelial and synovial cells and that the number of pili expressed by the bacterium correlates with the level of adherence to synovial cells but not with the level of adherence to respiratory cells. In addition, we established that the major pilin subunit is encoded by a pilA homolog in a conserved region of the chromosome that also contains a second pilin gene and a type IV pilus accessory gene, both of which are dispensable for pilus assembly and pilus-mediated adherence. Upon examination of the K. kingae genome, we identified two genes in physically separate locations on the chromosome that encode homologs of the Neisseria PilC proteins and that have only a low level homology to each other. Examination of mutant strains revealed that both of the K. kingae PilC homologs are essential for a wild-type level of adherence to both respiratory epithelial and synovial cells. Taken together, these results demonstrate that type IV pili and the two PilC homologs play important roles in mediating K. kingae adherence. PMID:18757541

  16. Characterization of type IV pilus genes in plant growth-promoting Pseudomonas putida WCS358.

    PubMed Central

    de Groot, A; Heijnen, I; de Cock, H; Filloux, A; Tommassen, J

    1994-01-01

    In a search for factors that could contribute to the ability of the plant growth-stimulating Pseudomonas putida WCS358 to colonize plant roots, the organism was analyzed for the presence of genes required for pilus biosynthesis. The pilD gene of Pseudomonas aeruginosa, which has also been designated xcpA, is involved in protein secretion and in the biogenesis of type IV pili. It encodes a peptidase that processes the precursors of the pilin subunits and of several components of the secretion apparatus. Prepilin processing activity could be demonstrated in P. putida WCS358, suggesting that this nonpathogenic strain may contain type IV pili as well. A DNA fragment containing the pilD (xcpA) gene of P. putida was cloned and found to complement a pilD (xcpA) mutation in P. aeruginosa. Nucleotide sequencing revealed, next to the pilD (xcpA) gene, the presence of two additional genes, pilA and pilC, that are highly homologous to genes involved in the biogenesis of type IV pili. The pilA gene encodes the pilin subunit, and pilC is an accessory gene, required for the assembly of the subunits into pili. In comparison with the pil gene cluster in P. aeruginosa, a gene homologous to pilB is lacking in the P. putida gene cluster. Pili were not detected on the cell surface of P. putida itself, not even when pilA was expressed from the tac promoter on a plasmid, indicating that not all the genes required for pilus biogenesis were expressed under the conditions tested. Expression of pilA of P. putida in P. aeruginosa resulted in the production of pili containing P. putida PilA subunits. Images PMID:7905475

  17. Translocation of Helicobacter pylori CagA into Gastric Epithelial Cells by Type IV Secretion

    NASA Astrophysics Data System (ADS)

    Odenbreit, Stefan; Püls, Jürgen; Sedlmaier, Bettina; Gerland, Elke; Fischer, Wolfgang; Haas, Rainer

    2000-02-01

    The Gram-negative bacterium Helicobacter pylori is a causative agent of gastritis and peptic ulcer disease in humans. Strains producing the CagA antigen (cagA+) induce strong gastric inflammation and are strongly associated with gastric adenocarcinoma and MALT lymphoma. We show here that such strains translocate the bacterial protein CagA into gastric epithelial cells by a type IV secretion system, encoded by the cag pathogenicity island. CagA is tyrosine-phosphorylated and induces changes in the tyrosine phosphorylation state of distinct cellular proteins. Modulation of host cells by bacterial protein translocation adds a new dimension to the chronic Helicobacter infection with yet unknown consequences.

  18. Basilar impression complicating osteogenesis imperfecta type IV: the clinical and neuroradiological findings in four cases

    PubMed Central

    Hayes, M; Parker, G; Ell, J; Sillence, D

    1999-01-01

    OBJECTIVES—To describe the clinical and neuroradiological features of basilar impression in patients with osteogenesis imperfecta type IV.
METHODS—Four patients with basilar impression were ascertained in a population study of osteogenesis imperfecta. All four had detailed clinical and neuroradiological examination with both CT and MRI of the craniocervical junction andposterior fossa structures.
RESULTS—All four showed significant compression of the posterior fossa structures and surgical decompression was performed with relief of symptoms.
CONCLUSION—Symptoms of cough headache and trigeminal neuralgia occurring in patients with osteogenesis imperfecta are indications for detailed clinical and neuroradiological investigation to document basilar impression.

 PMID:10084535

  19. Neural correlates of adaptive working memory training in a glycogen storage disease type-IV patient.

    PubMed

    Lee, Kristin; Ernst, Thomas; Løhaugen, Gro; Zhang, Xin; Chang, Linda

    2017-03-01

    Glycogen storage disease type-IV has varied clinical presentations and subtypes. We evaluated a 38-year-old man with memory complaints, common symptoms in adult polyglucosan body disease subtype, and investigated cognitive and functional MRI changes associated with two 25-sessions of adaptive working memory training. He showed improved trained and nontrained working memory up to 6-months after the training sessions. On functional MRI, he showed increased cortical activation 1-3 months after training, but both increased and decreased activation 6-months later. Working memory training appears to be beneficial to patients with adult polyglucosan body disease, although continued training may be required to maintain improvements.

  20. Thompson and Hamilton type IV Freiberg's disease with involvement of multiple epiphyses of both feet.

    PubMed

    Lui, Tun Hing

    2015-02-26

    A 17-year-old boy reported left second and third toe pain after axial loading injury to his left foot. Radiographs showed collapse of the second metatarsal heads and epiphysial irregularities of the fifth metatarsal heads and the condyle of the proximal phalanx of the hallux of both feet. The patient was diagnosed to have Thompson and Hamilton type IV Freiberg's disease. He was screened for epiphysial dysplasia of the other sites. He had on and off bilateral hip and knee pain. Radiographs showed bilateral symmetrical epiphysial abnormalities with morphological change as focal concavity in bilateral femoral heads and fragmentation of the patellar articular surface with preservation of the patellofemoral joint space.

  1. Host cell surfaces induce a Type IV pili-dependent alteration of bacterial swimming

    PubMed Central

    Golovkine, Guillaume; Lemelle, Laurence; Burny, Claire; Vaillant, Cedric; Palierne, Jean-Francois; Place, Christophe; Huber, Philippe

    2016-01-01

    For most pathogenic bacteria, flagellar motility is recognized as a virulence factor. Here, we analysed the swimming behaviour of bacteria close to eukaryotic cellular surfaces, using the major opportunistic pathogen Pseudomonas aeruginosa as a model. We delineated three classes of swimming trajectories on both cellular surfaces and glass that could be differentiated by their speeds and local curvatures, resulting from different levels of hydrodynamic interactions with the surface. Segmentation of the trajectories into linear and curved sections or pause allowed us to precisely describe the corresponding swimming patterns near the two surfaces. We concluded that (i) the trajectory classes were of same nature on cells and glass, however the trajectory distribution was strikingly different between surface types, (ii) on cell monolayers, a larger fraction of bacteria adopted a swimming mode with stronger bacteria-surface interaction mostly dependent upon Type IV pili. Thus, bacteria swim near boundaries with diverse patterns and importantly, Type IV pili differentially influence swimming near cellular and abiotic surfaces. PMID:27966607

  2. Two types of lanthanide selenidostannates(IV) first prepared under the same solvothermal conditions.

    PubMed

    Zhou, Jian; Xiao, Hong; Xiao, Hong-Ping; Yang, Tao; Zou, Hua-Hong; Liu, Xing; Zhao, Rong-Qing; Tang, Qiuling

    2015-01-21

    Two types of lanthanide selenidostannates(iv) [Ln2(tepa)2(μ-OH)2Sn2Se6] {Ln = Y(), Pr (), Dy (), Er (), Tm (); tepa = tetraethylenepentamine} and [Ln2(tepa)2(μ2-OH)2Cl2]2[Sn4Se10]·4H2O {Ln = Y (), Dy (), Er (), Tm ()} have been synthesized under identical solvothermal conditions and characterized structurally. Type I (, , , and ) displays 1-D neutral chains [Ln2(tepa)2(μ-OH)2Sn2Se6]n, while type II (, , and ) contains discrete adamantane-like [Sn4Se10](4-) ions with binuclear lanthanide complex [Ln2(tepa)2(μ-OH)2Cl2](2+) ions as counterions. Although the solvothermal synthetic methods could result in the formation of various transition-metal chalcogenidometalates, such identical experimental conditions usually result in the only stable phases of lanthanide chalcogenidometalates. Hence, two different lanthanide selenidostannates(iv), obtained under same solvothermal conditions and starting materials, have been first observed in this work. The optical properties of all the compounds have been investigated by UV-vis spectra.

  3. DSMC Simulation of Shock/Shock Interactions: Emphasis on Type IV Interactions

    NASA Technical Reports Server (NTRS)

    Moss, J. N.; Pot, T.; Chanetz, B.; Lefebvre, M.

    1999-01-01

    This paper presents the results of a numerical study of shock/shock interactions that include both the Edney type IV and type III interactions, with emphasis on the type IV interactions. Computations are made using the direct simulation Monte Carlo (DSMC) method of Bird for Mach 10 air flow, as produced in the ONERA R5Ch low-density wind tunnel. The simulations include the flow about a shock generator which creates a relatively weak oblique shock that impinges on a much stronger cylinder bow shock. The sensitivity and characteristics of the interactions are examined by varying the horizontal distance separating the shock generator leading edge and cylinder. Results of the simulation for one separation distance are compared with wind tunnel measurements. Comparisons are made for surface heating and pressure and for flow-field values of density and rotational temperatures, as obtained with the Dual-line Coherent Anti-Stokes Scattering (DL-CARS) technique. The comparisons between experiment and calculation yield a consistent description of the shock interaction features and a consistent description of the surface heating and pressure distributions, with the exception of the peak values-the computed values being greater than the measured values.

  4. Galactose recognition by a tetrameric C-type lectin, CEL-IV, containing the EPN carbohydrate recognition motif.

    PubMed

    Hatakeyama, Tomomitsu; Kamiya, Takuro; Kusunoki, Masami; Nakamura-Tsuruta, Sachiko; Hirabayashi, Jun; Goda, Shuichiro; Unno, Hideaki

    2011-03-25

    CEL-IV is a C-type lectin isolated from a sea cucumber, Cucumaria echinata. This lectin is composed of four identical C-type carbohydrate-recognition domains (CRDs). X-ray crystallographic analysis of CEL-IV revealed that its tetrameric structure was stabilized by multiple interchain disulfide bonds among the subunits. Although CEL-IV has the EPN motif in its carbohydrate-binding sites, which is known to be characteristic of mannose binding C-type CRDs, it showed preferential binding of galactose and N-acetylgalactosamine. Structural analyses of CEL-IV-melibiose and CEL-IV-raffinose complexes revealed that their galactose residues were recognized in an inverted orientation compared with mannose binding C-type CRDs containing the EPN motif, by the aid of a stacking interaction with the side chain of Trp-79. Changes in the environment of Trp-79 induced by binding to galactose were detected by changes in the intrinsic fluorescence and UV absorption spectra of WT CEL-IV and its site-directed mutants. The binding specificity of CEL-IV toward complex oligosaccharides was analyzed by frontal affinity chromatography using various pyridylamino sugars, and the results indicate preferential binding to oligosaccharides containing Galβ1-3/4(Fucα1-3/4)GlcNAc structures. These findings suggest that the specificity for oligosaccharides may be largely affected by interactions with amino acid residues in the binding site other than those determining the monosaccharide specificity.

  5. Systemic Correction of Murine Glycogen Storage Disease Type IV by an AAV-Mediated Gene Therapy.

    PubMed

    Yi, Haiqing; Zhang, Quan; Brooks, Elizabeth D; Yang, Chunyu; Thurberg, Beth L; Kishnani, Priya S; Sun, Baodong

    2016-11-10

    Deficiency of glycogen branching enzyme (GBE) causes glycogen storage disease type IV (GSD IV), which is characterized by the accumulation of a less branched, poorly soluble form of glycogen called polyglucosan (PG) in multiple tissues. This study evaluates the efficacy of gene therapy with an adeno-associated viral (AAV) vector in a mouse model of adult form of GSD IV (Gbe1(ys/ys)). An AAV serotype 9 (AAV9) vector containing a human GBE expression cassette (AAV-GBE) was intravenously injected into 14-day-old Gbe1(ys/ys) mice at a dose of 5 × 10(11) vector genomes per mouse. Mice were euthanized at 3 and 9 months of age. In the AAV-treated mice at 3 months of age, GBE enzyme activity was highly elevated in heart, which is consistent with the high copy number of the viral vector genome detected. GBE activity also increased significantly in skeletal muscles and the brain, but not in the liver. The glycogen content was reduced to wild-type levels in muscles and significantly reduced in the liver and brain. At 9 months of age, though GBE activity was only significantly elevated in the heart, glycogen levels were significantly reduced in the liver, brain, and skeletal muscles of the AAV-treated mice. In addition, the AAV treatment resulted in an overall decrease in plasma activities of alanine transaminase, aspartate transaminase, and creatine kinase, and a significant increase in fasting plasma glucose concentration at 9 months of age. This suggests an alleviation of damage and improvement of function in the liver and muscles by the AAV treatment. This study demonstrated a long-term benefit of a systemic injection of an AAV-GBE vector in Gbe1(ys/ys) mice.

  6. Glycosylation modulates melanoma cell α2β1 and α3β1 integrin interactions with type IV collagen.

    PubMed

    Stawikowski, Maciej J; Aukszi, Beatrix; Stawikowska, Roma; Cudic, Mare; Fields, Gregg B

    2014-08-01

    Although type IV collagen is heavily glycosylated, the influence of this post-translational modification on integrin binding has not been investigated. In the present study, galactosylated and nongalactosylated triple-helical peptides have been constructed containing the α1(IV)382-393 and α1(IV)531-543 sequences, which are binding sites for the α2β1 and α3β1 integrins, respectively. All peptides had triple-helical stabilities of 37 °C or greater. The galactosylation of Hyl(393) in α1(IV)382-393 and Hyl(540) and Hyl(543) in α1(IV)531-543 had a dose-dependent influence on melanoma cell adhesion that was much more pronounced in the case of α3β1 integrin binding. Molecular modeling indicated that galactosylation occurred on the periphery of α2β1 integrin interaction with α1(IV)382-393 but right in the middle of α3β1 integrin interaction with α1(IV)531-543. The possibility of extracellular deglycosylation of type IV collagen was investigated, but no β-galactosidase-like activity capable of collagen modification was found. Thus, glycosylation of collagen can modulate integrin binding, and levels of glycosylation could be altered by reduction in expression of glycosylation enzymes but most likely not by extracellular deglycosylation activity.

  7. Glycosylation Modulates Melanoma Cell α2β1 and α3β1 Integrin Interactions with Type IV Collagen*

    PubMed Central

    Stawikowski, Maciej J.; Aukszi, Beatrix; Stawikowska, Roma; Cudic, Mare; Fields, Gregg B.

    2014-01-01

    Although type IV collagen is heavily glycosylated, the influence of this post-translational modification on integrin binding has not been investigated. In the present study, galactosylated and nongalactosylated triple-helical peptides have been constructed containing the α1(IV)382–393 and α1(IV)531–543 sequences, which are binding sites for the α2β1 and α3β1 integrins, respectively. All peptides had triple-helical stabilities of 37 °C or greater. The galactosylation of Hyl393 in α1(IV)382–393 and Hyl540 and Hyl543 in α1(IV)531–543 had a dose-dependent influence on melanoma cell adhesion that was much more pronounced in the case of α3β1 integrin binding. Molecular modeling indicated that galactosylation occurred on the periphery of α2β1 integrin interaction with α1(IV)382–393 but right in the middle of α3β1 integrin interaction with α1(IV)531–543. The possibility of extracellular deglycosylation of type IV collagen was investigated, but no β-galactosidase-like activity capable of collagen modification was found. Thus, glycosylation of collagen can modulate integrin binding, and levels of glycosylation could be altered by reduction in expression of glycosylation enzymes but most likely not by extracellular deglycosylation activity. PMID:24958723

  8. Agrobacterium rhizogenes GALLS Protein Contains Domains for ATP Binding, Nuclear Localization, and Type IV Secretion▿

    PubMed Central

    Hodges, Larry D.; Vergunst, Annette C.; Neal-McKinney, Jason; den Dulk-Ras, Amke; Moyer, Deborah M.; Hooykaas, Paul J. J.; Ream, Walt

    2006-01-01

    Agrobacterium tumefaciens and Agrobacterium rhizogenes are closely related plant pathogens that cause different diseases, crown gall and hairy root. Both diseases result from transfer, integration, and expression of plasmid-encoded bacterial genes located on the transferred DNA (T-DNA) in the plant genome. Bacterial virulence (Vir) proteins necessary for infection are also translocated into plant cells. Transfer of single-stranded DNA (ssDNA) and Vir proteins requires a type IV secretion system, a protein complex spanning the bacterial envelope. A. tumefaciens translocates the ssDNA-binding protein VirE2 into plant cells, where it binds single-stranded T-DNA and helps target it to the nucleus. Although some strains of A. rhizogenes lack VirE2, they are pathogenic and transfer T-DNA efficiently. Instead, these bacteria express the GALLS protein, which is essential for their virulence. The GALLS protein can complement an A. tumefaciens virE2 mutant for tumor formation, indicating that GALLS can substitute for VirE2. Unlike VirE2, GALLS contains ATP-binding and helicase motifs similar to those in TraA, a strand transferase involved in conjugation. Both GALLS and VirE2 contain nuclear localization sequences and a C-terminal type IV secretion signal. Here we show that mutations in any of these domains abolished the ability of GALLS to substitute for VirE2. PMID:17012398

  9. Digenic mutations involving both the BSND and GJB2 genes detected in Bartter syndrome type IV.

    PubMed

    Wang, Hong-Han; Feng, Yong; Li, Hai-Bo; Wu, Hong; Mei, Ling-Yun; Wang, Xing-Wei; Jiang, Lu; He, Chu-Feng

    2017-01-01

    Bartter syndrome type IV, characterized by salt-losing nephropathies and sensorineural deafness, is caused by mutations of BSND or simultaneous mutations of both CLCNKA and CLCNKB. GJB2 is the primary causative gene for non-syndromic sensorineural deafness and associated with several syndromic sensorineural deafness. Owing to the rarity of Bartter syndrome, only a few mutations have been reported in the abovementioned causative genes. To investigate the underlying mutations in a Chinese patient with Bartter syndrome type IV, genetic analysis of BSND, CLCNKA, CLCNKB and GJB2 were performed by polymerase chain reaction and direct sequencing. Finally, double homozygous mutations c.22C > T (p.Arg8Trp) and c.127G > A (Val43Ile) were detected in exon 1 of BSND. Intriguingly, compound heterozygous mutations c.235delC (p.Leu79CysfsX3) and c.109G > A (p.Val37Ile) were also revealed in exon 2 of GJB2 in the same patient. No pathogenic mutations were found in CLCNKA and CLCNKB. Our results indicated that the homozygous mutation c.22C > T was the key genetic reason for the proband, and a digenic effect of BSND and GJB2 might contributed to sensorineural deafness. To our knowledge, it was the first report showing that the GJB2 gene mutations were detected in Bartter syndrome.

  10. Distinct activities of Bartonella henselae type IV secretion effector proteins modulate capillary-like sprout formation.

    PubMed

    Scheidegger, F; Ellner, Y; Guye, P; Rhomberg, T A; Weber, H; Augustin, H G; Dehio, C

    2009-07-01

    The zoonotic pathogen Bartonella henselae (Bh) can lead to vasoproliferative tumour lesions in the skin and inner organs known as bacillary angiomatosis and bacillary peliosis. The knowledge on the molecular and cellular mechanisms involved in this pathogen-triggered angiogenic process is confined by the lack of a suitable animal model and a physiologically relevant cell culture model of angiogenesis. Here we employed a three-dimensional in vitro angiogenesis assay of collagen gel-embedded endothelial cell (EC) spheroids to study the angiogenic properties of Bh. Spheroids generated from Bh-infected ECs displayed a high capacity to form sprouts, which represent capillary-like projections into the collagen gel. The VirB/VirD4 type IV secretion system and a subset of its translocated Bartonella effector proteins (Beps) were found to profoundly modulate this Bh-induced sprouting activity. BepA, known to protect ECs from apoptosis, strongly promoted sprout formation. In contrast, BepG, triggering cytoskeletal rearrangements, potently inhibited sprouting. Hence, the here established in vitro model of Bartonella- induced angiogenesis revealed distinct and opposing activities of type IV secretion system effector proteins, which together with a VirB/VirD4-independent effect may control the angiogenic activity of Bh during chronic infection of the vasculature.

  11. Open angle glaucoma in a case of Type IV Ehler Danlos syndrome: a rarely reported association.

    PubMed

    Mitra, Arijit; Ramakrishnan, R; Kader, Mohideen Abdul

    2014-08-01

    A 26-year-old male presented to us with defective vision in the left eye. He had best corrected visual acuity (BCVA) of hand movement (HM) in right eye and 6/9 in left eye. He had ptosis with ectropion in both eyes and relative afferent pupillary defect (RAPD) in right eye. Intraocular pressure (IOP) was 46 and 44 mmHg in right and left eye, respectively. Fundus showed glaucomatous optic atrophy (GOA) in right eye and cup disc ratio (CDR) of 0.75 with bipolar rim thinning in left eye. Systemic examination showed hyperextensible skin and joints, acrogeria, hypodontia, high arched palate, and varicose veins. He gave history of easy bruising and tendency to fall and history of intestinal rupture 5 years ago for which he had undergone surgery. He was diagnosed as a case of Type IV Ehler-Danlos syndrome (EDS) with open angle glaucoma. He underwent trabeculectomy in both eyes. This is a rare case that shows glaucoma in a patient of EDS Type IV. Very few such cases have been reported in literature.

  12. Open angle glaucoma in a case of Type IV Ehler Danlos syndrome: A rarely reported association

    PubMed Central

    Mitra, Arijit; Ramakrishnan, R.; Kader, Mohideen Abdul

    2014-01-01

    A 26-year-old male presented to us with defective vision in the left eye. He had best corrected visual acuity (BCVA) of hand movement (HM) in right eye and 6/9 in left eye. He had ptosis with ectropion in both eyes and relative afferent pupillary defect (RAPD) in right eye. Intraocular pressure (IOP) was 46 and 44 mmHg in right and left eye, respectively. Fundus showed glaucomatous optic atrophy (GOA) in right eye and cup disc ratio (CDR) of 0.75 with bipolar rim thinning in left eye. Systemic examination showed hyperextensible skin and joints, acrogeria, hypodontia, high arched palate, and varicose veins. He gave history of easy bruising and tendency to fall and history of intestinal rupture 5 years ago for which he had undergone surgery. He was diagnosed as a case of Type IV Ehler-Danlos syndrome (EDS) with open angle glaucoma. He underwent trabeculectomy in both eyes. This is a rare case that shows glaucoma in a patient of EDS Type IV. Very few such cases have been reported in literature. PMID:25230966

  13. Earthworm symbiont Verminephrobacter eiseniae mediates natural transformation within host egg capsules using type IV pili

    PubMed Central

    Davidson, Seana K.; Dulla, Glenn F.; Go, Ruth A.; Stahl, David A.; Pinel, Nicolás

    2014-01-01

    The dense microbial communities commonly associated with plants and animals should offer many opportunities for horizontal gene transfer through described mechanisms of DNA exchange including natural transformation (NT). However, studies of the significance of NT have focused primarily on pathogens. The study presented here demonstrates highly efficient DNA exchange by NT in a common symbiont of earthworms. The obligate bacterial symbiont Verminephrobacter eiseniae is a member of a microbial consortium of the earthworm Eisenia fetida that is transmitted into the egg capsules to colonize the embryonic worms. In the study presented here, by testing for transformants under different conditions in culture, we demonstrate that V. eiseniae can incorporate free DNA from the environment, that competency is regulated by environmental factors, and that it is sequence specific. Mutations in the type IV pili of V. eiseniae resulted in loss of DNA uptake, implicating the type IV pilus (TFP) apparatus in DNA uptake. Furthermore, injection of DNA carrying antibiotic-resistance genes into egg capsules resulted in transformants within the capsule, demonstrating the relevance of DNA uptake within the earthworm system. The ability to take up species-specific DNA from the environment may explain the maintenance of the relatively large, intact genome of this long-associated obligate symbiont, and provides a mechanism for acquisition of foreign genes within the earthworm system. PMID:25400622

  14. Apical leakage in maxillary type IV premolars with three different endodontic treatments.

    PubMed

    Staribratova-Reister, K; Reister, J P; Attin, T; Martus, P; Kielbassa, A M

    2003-09-01

    The aim of this study was to evaluate the sealing ability in orthogradely filled, apicoectomised and retrogradely filled maxillary premolars with two canals and two separate apical foramina. The root canals of 51 extracted maxillary premolars of type IV were uniformly shaped and filled by means of lateral condensation and subsequently randomly divided into three groups of 17 teeth each. The teeth of groups II and III received an apicoectomy. In group III an additional retrograde seal (Ketac Fil) was applied. Group I served as control. All specimens were immersed in a methylene blue solution for 24 h. The teeth were cross-sectioned and the maximal dye-penetration was measured. The significantly least dye-penetration was observed in group II (apicoectomy only), followed by group I and group III. The differences among all groups were statistically significant (p<0.05). Most of the retrograde restorations in group III revealed circular colouration around the retrograde fillings extending to the gutta percha. Although the teeth of group II revealed the least dye-penetration, an apicoectomy cannot be favoured against an endodontic retreatment in maxillary premolars of type IV. The application of retrograde fillings using Ketac Fil must be considered critically.

  15. Interaction of Type IV Toxin/Antitoxin Systems in Cryptic Prophages of Escherichia coli K-12

    PubMed Central

    Wen, Zhongling; Wang, Pengxia; Sun, Chenglong; Guo, Yunxue; Wang, Xiaoxue

    2017-01-01

    Toxin/antitoxin (TA) systems are widespread in prokaryotic chromosomes and in mobile genetic elements including plasmids and prophages. The first characterized Type IV TA system CbtA/CbeA was found in cryptic prophage CP4-44 in Escherichia coli K-12. Two homologous TA loci of CbtA/CbeA also reside in cryptic prophages of E. coli K-12, YkfI/YafW in CP4-6 and YpjF/YfjZ in CP4-57. In this study, we demonstrated that YkfI and YpjF inhibited cell growth and led to the formation of “lemon-shaped” cells. Prolonged overproduction of YkfI led to the formation of “gourd-shaped” cells and immediate cell lysis. YafW and YfjZ can neutralize the toxicity of YkfI or YpjF. Furthermore, we found that YkfI and YpjF interacted with cell division protein FtsZ in E. coli, but ectopic expression in Pseudomonas and Shewanella did not cause the formation of “lemon-shaped” cells. Moreover, deletion of all of the three toxin genes together decreased resistance to oxidative stress and deletion of the antitoxin genes increased early biofilm formation. Collectively, these results demonstrated that the homologous Type IV TA systems in E. coli may target cell division protein FtsZ in E. coli and may have different physiological functions in E. coli. PMID:28257056

  16. Identification, Immunogenicity and Crossreactivity of Type IV Pilin and Pilin-like Proteins from Clostridium difficile

    PubMed Central

    Maldarelli, Grace A.; De Masi, Leon; von Rosenvinge, Erik C.; Carter, Mihaela; Donnenberg, Michael S.

    2014-01-01

    The Gram-positive anaerobe Clostridium difficile is the major cause of nosocomial diarrhea; manifestations of infection include diarrhea, pseudomembranous colitis, and death. Genes for type IV pili, a bacterial nanofiber often involved in colonization and until relatively recently described only in Gram-negatives, are present in all members of the Clostridiales. We hypothesized that any pilins encoded in the C. difficile genome would be immunogenic, as has been shown with pilins from Gram-negative organisms. We describe nine pilin or pilin-like protein genes, for which we introduce a coherent nomenclature, in the C. difficile R20291 genome. The nine predicted pilin or pilin-like proteins have relatively conserved N-terminal hydrophobic regions, but diverge at their C-termini. Analysis of synonymous and nonsynonymous substitutions revealed evidence of diversifying selective pressure in two pilin genes. Six of the nine identified proteins were purified and used to immunize mice. Immunization of mice with each individual protein generated antibody responses that varied in titer and crossreactivity, a notable result given the low amino acid sequence identity among the pilins. Further studies in other small mammals mirrored our results in mice. Our results illuminate components of the C. difficile type IV pilus, and help identify targets for an anti-C. difficile vaccine. PMID:24550179

  17. Collagen type IV stimulates an increase in intracellular Ca2+ in pancreatic acinar cells via activation of phospholipase C.

    PubMed Central

    Somogyi, L; Lasić, Z; Vukicević, S; Banfić, H

    1994-01-01

    Intracellular Ca2+ responses to extracellular matrix molecules were studied in suspensions of pancreatic acinar cells loaded with Fura-2. Collagen type I, laminin, fibrinogen and fibronectin were unable to raise cytosolic free Ca2+ concentration ([Ca2+]i), whereas collagen type IV, at concentrations from 5 to 50 micrograms/ml, significantly increased it. The effect of collagen type IV was not due to possible contamination with type-I transforming growth factor beta or plasminogen, as neither of these agents was able to increase [Ca2+]i. Using highly specific mass assays, concentrations of inositol lipids, 1,2-diacylglycerol (DAG) and Ins(1,4,5) P3 were measured in pancreatic acinar cells stimulated with collagen type IV. A decrease in the concentrations of PtdIns(4,5) P2 and PtdIns4 P with a concomitant increase in the concentrations of DAG and InsP3 mass were observed, showing that collagen type IV increases [Ca2+]i by activation of phospholipase C. The observed [Ca2+]i signals had two components, the first resulting from Ca2+ release from the intracellular stores, and the second resulting from Ca2+ flux from the extracellular medium through the verapamil-insensitive channels. A tyrosine kinase inhibitor (tyrphostine) was able to block inositol lipid signalling caused by collagen type IV, which together with the insensitivity of this pathway to cholera toxin and pertussis toxin or to preactivation of protein kinase C, the longer duration of the increase in [Ca2+]i and a longer lag period needed for observation of increases in DAG and InsP3 concentration with collagen type IV than with carbachol (50 mM) suggest that activation of phospholipase C by collagen type IV is caused by tyrosine kinase activation. Inositol lipid signalling and increases in [Ca2+]i were also observed with Arg-Gly-Asp (RGD)-containing peptide but not with Arg-Asp-Gly (RDG)-containing peptide. Collagen type IV and RGD-containing peptide, but not carbachol, competed in increasing [Ca2+]i and

  18. Trp-Arg-Xaa tripeptides act as uncompetitive-type inhibitors of human dipeptidyl peptidase IV.

    PubMed

    Lan, Vu Thi Tuyet; Ito, Keisuke; Ito, Sohei; Kawarasaki, Yasuaki

    2014-04-01

    Human dipeptidyl peptidase IV (hDPPIV, alternative name: CD26) inhibitors provide an effective strategy for the treatment of type 2 diabetes. Recently, our research group discovered a non substrate-mimic inhibitory dipeptide, Trp-Arg, by the systematic analysis of a dipeptide library. In the present study, a tripeptide library Trp-Arg-Xaa (where Xaa represents any amino acid) was analyzed to investigate the interactions of peptidergic inhibitors with hDPPIV. Trp-Arg-Glu showed the highest inhibitory effect toward hDPPIV (Ki=130 μM). All of the tested 19 Trp-Arg-Xaa tripeptides showed unique uncompetitive-type inhibition. The inhibition mechanism of Trp-Arg-Xaa is discussed based on the crystal structure of hDPPIV. The information obtained by this study suggests a novel concept for developing hDPPIV inhibitory peptides and drugs.

  19. Bifurcations in a Seasonally Forced Predator-Prey Model with Generalized Holling Type IV Functional Response

    NASA Astrophysics Data System (ADS)

    Ren, Jingli; Li, Xueping

    A seasonally forced predator-prey system with generalized Holling type IV functional response is considered in this paper. The influence of seasonal forcing on the system is investigated via numerical bifurcation analysis. Bifurcation diagrams for periodic solutions of periods one and two, containing bifurcation curves of codimension one and bifurcation points of codimension two, are obtained by means of a continuation technique, corresponding to different bifurcation cases of the unforced system illustrated in five bifurcation diagrams. The seasonally forced model exhibits more complex dynamics than the unforced one, such as stable and unstable periodic solutions of various periods, stable and unstable quasiperiodic solutions, and chaotic motions through torus destruction or cascade of period doublings. Finally, some phase portraits and corresponding Poincaré map portraits are given to illustrate these different types of solutions.

  20. Homozygous factor V Leiden mutation in type IV Ehlers-Danlos patient

    PubMed Central

    Refaat, Marwan; Hotait, Mostafa; Winston, Brion

    2014-01-01

    Ehlers-Danlos syndrome (EDS) is a group of inherited connective tissue disorders caused by collagen synthesis defects. Several hemostatic abnormalities have been described in EDS patients that increase the bleeding tendencies of these patients. This case report illustrates a patient with an unusual presentation of a patient with type IV EDS, platelet δ-storage pool disease and factor V Leiden mutation. Young woman having previous bilateral deep vein thrombosis and pulmonary emboli coexisting with ruptured splenic aneurysm and multiple other aneurysms now presented with myocardial infarction. Presence of factor V Leiden mutation raises the possibility that the infarct was due to acute coronary thrombosis, although coronary artery aneurysm and dissection with myocardial infarction is known to occur in vascular type EDS. This is the first report in the medical literature of factor V Leiden mutation in an EDS patient which made the management of our patient challenging with propensity to both bleeding and clotting. PMID:24653990

  1. Characterization of type IV pilus genes in Pseudomonas syringae pv. tomato DC3000.

    PubMed

    Roine, E; Raineri, D M; Romantschuk, M; Wilson, M; Nunn, D N

    1998-11-01

    Many strains of Pseudomonas syringae produce retractile pili that act as receptors for lytic bacteriophage phi 6. As these are also characteristics of type IV pili, it was postulated that P. syringae may possess genes for type IV pilus biogenesis. A cosmid clone bank of P. syringae pv. tomato DC3000 genomic DNA was used to complement a mutant of Pseudomonas aeruginosa defective in the PilD (XcpA) prepilin peptidase gene by selection for restoration of extracellular protein secretion, a function also known to require PilD. A cosmid able to complement this mutant was also able to complement mutations in the pilB and pilC genes, suggesting that, if the organization of these genes is similar to that of P. aeruginosa, the cosmid may contain the P. syringae pilA. This was confirmed by sequencing a region from this plasmid that was shown to hybridize at low stringency to the P. aeruginosa pilA gene. The deduced P. syringae PilA polypeptide possesses the characteristic properties of the type IV pilins. Heterologous expression of the P. syringae pilA in P. aeruginosa was also shown, conferring not only phi 6 phage sensitivity to P. aeruginosa pilA mutants but also sensitivity to PO4, a lytic bacteriophage specific for the pilus of P. aeruginosa. This suggests that additional components might be present in the mature pilus of P. aeruginosa that are the true receptors for this phage. Chromosomal mutations in P. syringae pv. tomato DC3000 pilA and pilD genes were shown to abolish its sensitivity to bacteriophage phi 6. To determine the importance of P. syringae pilus in plant leaf interactions, these mutations were tested under laboratory and field conditions. Although little effect was seen on pathogenicity, culturable leaf-associated population sizes of the pilA mutant were significantly different from those of the wild-type parent. In addition, the expression of the DC3000 pilA gene appears to contribute to the UV tolerance of P. syringae and may play a role in survival on

  2. Drosophila type IV collagen mutation associates with immune system activation and intestinal dysfunction.

    PubMed

    Kiss, Márton; Kiss, András A; Radics, Monika; Popovics, Nikoletta; Hermesz, Edit; Csiszár, Katalin; Mink, Mátyás

    2016-01-01

    The basal lamina (BM) contains numerous components with a predominance of type IV collagens. Clinical manifestations associated with mutations of the human COL4A1 gene include perinatal cerebral hemorrhage and porencephaly, hereditary angiopathy, nephropathy, aneurysms and muscle cramps (HANAC), ocular dysgenesis, myopathy, Walker–Warburg syndrome and systemic tissue degeneration. In Drosophila, the phenotype associated with dominant temperature sensitive mutations of col4a1 include severe myopathy resulting from massive degradation of striated muscle fibers, and in the gut, degeneration of circular visceral muscle cells and epithelial cells following detachment from the BM. In order to determine the consequences of altered BMfunctions due to aberrant COL4A1 protein, we have carried out a series of tests using Drosophila DTS-L3 mutants from our allelic series of col4a1 mutations with confirmed degeneration of various cell types and lowest survival rate among the col4a1 mutant lines at restrictive temperature. Results demonstrated epithelial cell degeneration in the gut, shortened gut, enlarged midgut with multiple diverticulae, intestinal dysfunction and shortened life span. Midgut immunohistochemistry analyses confirmed altered expression and distribution of BM components integrin PSI and PSII alpha subunits, laminin gamma 1, and COL4A1 both in larvae and adults. Global gene expression analysis revealed activation of the effector AMP genes of the primary innate immune system including Metchnikowin, Diptericin, Diptericin B, and edin that preceded morphological changes. Attacin::GFP midgut expression pattern further supported these changes. An increase in ROS production and changes in gut bacterial flora were also noted and may have further enhanced an immune response. The phenotypic features of Drosophila col4a1 mutants confirmed an essential role for type IV collagen in maintaining epithelial integrity, gut morphology and intestinal function and suggest that

  3. The Che4 pathway of Myxococcus xanthus regulates type IV pilus-mediated motility.

    PubMed

    Vlamakis, Hera C; Kirby, John R; Zusman, David R

    2004-06-01

    Myxococcus xanthus co-ordinates cell movement during its complex life cycle using multiple chemotaxis-like signal transduction pathways. These pathways regulate both type IV pilus-mediated social (S) motility and adventurous (A) motility. During a search for new chemoreceptors, we identified the che4 operon, which encodes homologues to a MCP (methyl-accepting chemotaxis protein), two CheWs, a hybrid CheA-CheY, a response regulator and a CheR. Deletion of the che4 operon did not cause swarming or developmental defects in either the wild-type (A(+)S(+)) strain or in a strain sustaining only A motility (A(+)S(-)). However, in a strain displaying only S motility (A(-)S(+)), deletion of the che4 operon or the gene encoding the response regulator, cheY4, caused enhanced vegetative swarming and prevented aggregation and sporulation. In contrast, deletion of mcp4 caused reduced vegetative swarming and enhanced development compared with the parent strain. Single-cell analysis of the motility of the A(-)S(+) parent strain revealed a previously unknown inverse correlation between velocity and reversal frequency. Thus, cells that moved at higher velocities showed a reduced reversal frequency. This co-ordination of reversal frequency and velocity was lost in the mcp4 and cheY4 mutants. The structural components of the S motility apparatus were unaffected in the che4 mutants, suggesting that the Che4 system affects reversal frequency of cells by modulating the function of the type IV pilus.

  4. Structural characterization of ribosome recruitment and translocation by type IV IRES.

    PubMed

    Murray, Jason; Savva, Christos G; Shin, Byung-Sik; Dever, Thomas E; Ramakrishnan, V; Fernández, Israel S

    2016-05-09

    Viral mRNA sequences with a type IV IRES are able to initiate translation without any host initiation factors. Initial recruitment of the small ribosomal subunit as well as two translocation steps before the first peptidyl transfer are essential for the initiation of translation by these mRNAs. Using electron cryomicroscopy (cryo-EM) we have structurally characterized at high resolution how the Cricket Paralysis Virus Internal Ribosomal Entry Site (CrPV-IRES) binds the small ribosomal subunit (40S) and the translocation intermediate stabilized by elongation factor 2 (eEF2). The CrPV-IRES restricts tvhe otherwise flexible 40S head to a conformation compatible with binding the large ribosomal subunit (60S). Once the 60S is recruited, the binary CrPV-IRES/80S complex oscillates between canonical and rotated states (Fernández et al., 2014; Koh et al., 2014), as seen for pre-translocation complexes with tRNAs. Elongation factor eEF2 with a GTP analog stabilizes the ribosome-IRES complex in a rotated state with an extra ~3 degrees of rotation. Key residues in domain IV of eEF2 interact with pseudoknot I (PKI) of the CrPV-IRES stabilizing it in a conformation reminiscent of a hybrid tRNA state. The structure explains how diphthamide, a eukaryotic and archaeal specific post-translational modification of a histidine residue of eEF2, is involved in translocation.

  5. Type III and type IV hypersensitivity reactions due to mitomycin C.

    PubMed

    Kunkeler, L; Nieboer, C; Bruynzeel, D P

    2000-02-01

    A 71-year-old man developed an exfoliative dermatitis of the palms of the hands and soles of the feet, and a generalized itch, during treatment with intravesical instillations of mitomycin C for an undifferentiated carcinoma of the bladder. Patch tests with mitomycin C 0.03%, 0.1% and 0.3% aq. were positive. Because of the serious consequences of this finding, the patient was retested with mitomycin C in pet. (same concentrations), a more stable preparation. This showed clear positive reactions. During this last series of patch tests, he developed palpable purpura on the legs. We postulated that this reaction was an immune-complex-mediated reaction, caused by the 2nd series of patch tests with mitomycin C. To prove this, we performed histopathological and immunofluorescence investigations, and these showed the reaction to be consistent with Henoch-Schonlein-type purpura. We therefore conclude that this patient developed systemic reactions to mitomycin C, characterized by an eczematous dermatitis as well as purpuric reactions. The intravesical installations with mitomycin C have been stopped. The patient's skin problems (the purpura as well as the eczema) have completely resolved and have not recurred.

  6. Characteristics of type IV collagen unfolding under various pH conditions as a model of pathological disorder in tissue.

    PubMed

    Shimizu, Akio; Kawai, Kenichi; Yanagino, Miki; Wakiyama, Toshiko; Machida, Minoru; Kameyama, Kohji; Naito, Zenya

    2007-07-01

    The overall structure of type IV collagen is the same at neutral and acidic pH, as determined by circular dichroism spectra. The heating rate dependence of denaturation midpoint temperature (T(m)) shows that type IV collagen is unstable at body temperature, similarly to type I collagen. The heating rate dependence of T(m) at neutral pH has two phases, but that at acidic pH apparently has a single phase. The T(m) of the first phase (lower T(m)) at neutral pH is consistent with that at acidic pH, and the activation energy of these phases is consistent, within experimental error. The triple helix region of type IV collagen corresponding to the second phase (higher T(m)) at neutral pH is thermally stable when compared to the triple helical structure at acidic pH. At acidic pH, as the loosely packed and unstable region has spread throughout the whole molecule, the thermal transition is thought to be cooperative and is observed as a single phase. Structural flexibility is related to protein function and assembly; therefore, the unstable structure and increased flexibility of type IV collagen induced at acidic pH may affect diseases accompanied by type IV collagen disorder.

  7. Longevity of dental implants in type IV bone: a systematic review.

    PubMed

    Goiato, M C; dos Santos, D M; Santiago, J F; Moreno, A; Pellizzer, E P

    2014-09-01

    Bone quality and quantity are important factors with regard to the survival rate of dental implants. The aim of this study was to conduct a systematic review of dental implants inserted in low-density bone and to determine the survival rate of dental implants with surface treatments over time. A systematic review of the literature was undertaken by two independent individuals; the Medline/PubMed database was searched for the period July 1975 to March 2013. Relevant reports on bone quality and osseointegration of dental implants were selected. The search retrieved 1018 references, and after inclusion and exclusion criteria were applied, 19 studies were selected for review. A total of 3937 patients, who had received a total of 12,465 dental implants, were analyzed. The survival rates of dental implants according to the bone density were: type I, 97.6%; type II, 96.2%; type III, 96.5%; and type IV, 88.8%. The survival rate of treated surface implants inserted in low-density bone was higher (97.1%) than that of machined surface implants (91.6%). Surface-treated dental implants inserted in low-density bone have a high survival rate and may be indicated for oral rehabilitation. However, more randomized studies are required to better evaluate this issue.

  8. Genes for collagen types I, IV, and V are transcribed in HeLa cells but a postinitiation block prevents the accumulation of type I mRNA

    SciTech Connect

    Furth, J.J.; Wroth, T.H.; Ackerman, S. )

    1991-01-01

    Collagen mRNA synthesis in HeLa cells was evaluated by in vitro transcription of type I collagen DNA, nuclear run-on studies, and steady-state mRNA analysis. Type I collagen mRNA was accurately initiated by HeLa cell RNQA polymerase II in nuclear extracts, and run-on analysis indicated that mRNAs for collagen types {alpha}1(I), {alpha}2(I), {alpha}1(III), {alpha}1(IV), and {alpha}2(V) were synthesized in HeLa cells. However, on assessing the steady-state levels of mRNAs of collagen types {alpha}1(I), {alpha}2(I), {alpha}1(IV), and {alpha}2(V), no type I mRNA was found in HeLa cells while types {alpha}1(IV) and {alpha}2(V) collagen mRNAs were observed. These results suggest that a postinitiation process prevents the accumulation of type I collagen mRNAs in HeLa cells. Persistence of types IV and V collagen mRNAs is consistent with the involvement of types IV and V collagen in adhesion of HeLa cells to glass or plastic.

  9. Composition, structure and function of the Helicobacter pylori cag pathogenicity island encoded type IV secretion system.

    PubMed

    Backert, Steffen; Tegtmeyer, Nicole; Fischer, Wolfgang

    2015-01-01

    Many Gram-negative pathogens harbor type IV secretion systems (T4SS) that translocate bacterial virulence factors into host cells to hijack cellular processes. The pathology of the gastric pathogen Helicobacter pylori strongly depends on a T4SS encoded by the cag pathogenicity island. This T4SS forms a needle-like pilus, and its assembly is accomplished by multiple protein-protein interactions and various pilus-associated factors that bind to integrins followed by delivery of the CagA oncoprotein into gastric epithelial cells. Recent studies revealed the crystal structures of six T4SS proteins and pilus formation is modulated by iron and zinc availability. All these T4SS interactions are crucial for deregulating host signaling events and disease progression. New developments in T4SS functions and their importance for pathogenesis are discussed.

  10. A Type IV Pilus Mediates DNA Binding during Natural Transformation in Streptococcus pneumoniae

    PubMed Central

    Laurenceau, Raphaël; Péhau-Arnaudet, Gérard; Baconnais, Sonia; Gault, Joseph; Malosse, Christian; Dujeancourt, Annick; Campo, Nathalie; Chamot-Rooke, Julia; Le Cam, Eric; Claverys, Jean-Pierre; Fronzes, Rémi

    2013-01-01

    Natural genetic transformation is widely distributed in bacteria and generally occurs during a genetically programmed differentiated state called competence. This process promotes genome plasticity and adaptability in Gram-negative and Gram-positive bacteria. Transformation requires the binding and internalization of exogenous DNA, the mechanisms of which are unclear. Here, we report the discovery of a transformation pilus at the surface of competent Streptococcus pneumoniae cells. This Type IV-like pilus, which is primarily composed of the ComGC pilin, is required for transformation. We provide evidence that it directly binds DNA and propose that the transformation pilus is the primary DNA receptor on the bacterial cell during transformation in S. pneumoniae. Being a central component of the transformation apparatus, the transformation pilus enables S. pneumoniae, a major Gram-positive human pathogen, to acquire resistance to antibiotics and to escape vaccines through the binding and incorporation of new genetic material. PMID:23825953

  11. A phage protein that inhibits the bacterial ATPase required for type IV pilus assembly.

    PubMed

    Chung, In-Young; Jang, Hye-Jeong; Bae, Hee-Won; Cho, You-Hee

    2014-08-05

    Type IV pili (TFPs) are required for bacterial twitching motility and for phage infection in the opportunistic human pathogen Pseudomonas aeruginosa. Here we describe a phage-encoded protein, D3112 protein gp05 (hereafter referred to as Tip, representing twitching inhibitory protein), whose expression is necessary and sufficient to mediate the inhibition of twitching motility. Tip interacts with and blocks the activity of bacterial-encoded PilB, the TFP assembly/extension ATPase, at an internal 40-aa region unique to PilB. Tip expression results in the loss of surface piliation. Based on these observations and the fact that many P. aeruginosa phages require TFPs for infection, Tip-mediated twitching inhibition may represent a generalized strategy for superinfection exclusion. Moreover, because TFPs are required for full virulence, PilB may be an attractive target for the development of novel antiinfectives.

  12. Widespread distribution and structural diversity of Type IV IRESs in members of Picornaviridae

    PubMed Central

    Asnani, Mukta; Kumar, Parimal; Hellen, Christopher U. T.

    2015-01-01

    Picornavirus genomes contain internal ribosomal entry sites (IRESs) that promote end-independent translation initiation. Five structural classes of picornavirus IRES have been identified, but numerous IRESs remain unclassified. Here, previously unrecognized Type IV IRESs were identified in members of three proposed picornavirus genera (Limnipivirus, Pasivirus, Rafivirus) and four recognized genera (Kobuvirus, Megrivirus, Sapelovirus, Parechovirus). These IRESs are ∼230–420 nucleotides long, reflecting heterogeneity outside a common structural core. Closer analysis yielded insights into evolutionary processes that have shaped contemporary IRESs. The presence of related IRESs in diverse genera supports the hypothesis that they are heritable genetic elements that spread by horizontal gene transfer. Recombination likely also accounts for the exchange of some peripheral subdomains, suggesting that IRES evolution involves incremental addition of elements to a pre-existing core. Nucleotide conservation is concentrated in ribosome-binding sites, and at the junction of helical domains, likely to ensure orientation of subdomains in an active conformation. PMID:25726971

  13. Hip resurfacing after iliofemoral distraction for type IV developmental dysplasia of the hip a case report.

    PubMed

    Sambri, A; Cadossi, M; Mazzotti, A; Faldini, C; Giannini, S

    2015-01-01

    Osteoarthritis secondary to developmental dysplasia of the hip is a surgical challenge because of the modified anatomy of the acetabulum which is deficient in its shape with poor bone quality, torsional deformities of the femur and the altered morphology of femoral head. Particularly in Crowe type III and IV, additional surgical challenges are present, such as limb-length discrepancy and adductor muscle contractures. This is a bilateral hip dysplasia case where bilateral hip replacement was indicated, on the left side with a resurfacing one and on the other side a two stage procedure using a iliofemoral external fixator to restore equal leg length with a lower risk of complications. This case report shows both the negative clinical outcome of the left and the excellent one of the right hip where the dysplasia was much more severe. Patient selection and implant positioning are crucial in determining long-term results.

  14. Type IV Creep Damage Behavior in Gr.91 Steel Welded Joints

    NASA Astrophysics Data System (ADS)

    Hongo, Hiromichi; Tabuchi, Masaaki; Watanabe, Takashi

    2012-04-01

    Modified 9Cr-1Mo steel (ASME Grade 91 steel) is used as a key structural material for boiler components in ultra-supercritical (USC) thermal power plants at approximately 873 K (600 °C). The creep strength of welded joints of this steel decreases as a result of Type IV creep cracking that forms in the heat-affected zone (HAZ) under long-term use at high temperatures. The current article aims to elucidate the damage processes and microstructural degradations that take place in the HAZ of these welded joints. Long-term creep tests for base metal, simulated HAZ, and welded joints were conducted at 823 K, 873 K, and 923 K (550 °C, 600 °C, and 650 °C). Furthermore, creep tests of thick welded joint specimens were interrupted at several time steps at 873 K (600 °C) and 90 MPa, after which the distribution and evolution of creep damage inside the plates were measured quantitatively. It was found that creep voids are initiated in the early stages (0.2 of life) of creep rupture life, which coalesce to form a crack at a later stage (0.8 of life). In a fine-grained HAZ, creep damage is concentrated chiefly in an area approximately 20 pct below the surface of the plate. The experimental creep damage distributions coincide closely with the computed results obtained by damage mechanics analysis using the creep properties of a simulated fine-grained HAZ. Both the concentration of creep strain and the high multiaxial stress conditions in the fine-grained HAZ influence the distribution of Type IV creep damage.

  15. BBA Review Revised Mechanism and Structure of the Bacterial Type IV Secretion Systems

    PubMed Central

    Christie, Peter J.; Whitaker, Neal; González-Rivera, Christian

    2014-01-01

    The bacterial type IV secretion systems (T4SSs) translocate DNA and protein substrates to bacterial or eukaryotic target cells generally by a mechanism dependent on direct cell-to-cell contact. The T4SSs encompass two large subfamilies, the conjugation systems and the effector translocators. The conjugation systems mediate interbacterial DNA transfer and are responsible for the rapid dissemination of antibiotic resistance genes and virulence determinants in clinical settings. The effector translocators are used by many Gram-negative bacterial pathogens for delivery of potentially hundreds of virulence proteins to eukaryotic cells for modulation of different physiological processes during infection. Recently, there has been considerable progress in defining the structures of T4SS machine subunits and large machine subassemblies. Additionally, the nature of substrate translocation sequences and the contributions of accessory proteins to substrate docking with the translocation channel have been elucidated. A DNA translocation route through the Agrobacterium tumefaciens VirB/VirD4 system was defined, and both intracellular (DNA ligand, ATP energy) and extracellular (phage binding) signals were shown to activate type IV-dependent translocation. Finally, phylogenetic studies have shed light on the evolution and distribution of T4SSs, and complementary structure-function studies of diverse systems have identified adaptations tailored for novel functions in pathogenic settings. This review summarizes the recent progress in our understanding of the architecture and mechanism of action of these fascinating machines, with emphasis on the ‘archetypal’ A. tumefaciens VirB/VirD4 T4SS and related conjugation systems. PMID:24389247

  16. Expression of Cellulosome Components and Type IV Pili within the Extracellular Proteome of Ruminococcus flavefaciens 007

    PubMed Central

    Vodovnik, Maša; Duncan, Sylvia H.; Reid, Martin D.; Cantlay, Louise; Turner, Keith; Parkhill, Julian; Lamed, Raphael; Yeoman, Carl J.; Miller, Margret E. Berg.; White, Bryan A.; Bayer, Edward A.; Marinšek-Logar, Romana; Flint, Harry J.

    2013-01-01

    Background Ruminococcus flavefaciens is an important fibre-degrading bacterium found in the mammalian gut. Cellulolytic strains from the bovine rumen have been shown to produce complex cellulosome structures that are associated with the cell surface. R. flavefaciens 007 is a highly cellulolytic strain whose ability to degrade dewaxed cotton, but not Avicel cellulose, was lost following initial isolation in the variant 007S. The ability was recovered after serial subculture to give the cotton-degrading strain 007C. This has allowed us to investigate the factors required for degradation of this particularly recalcitrant form of cellulose. Methodology/Principal Findings The major proteins associated with the bacterial cell surface and with the culture supernatant were analyzed for R. flavefaciens 007S and 007C grown with cellobiose, xylan or Avicel cellulose as energy sources. Identification of the proteins was enabled by a draft genome sequence obtained for 007C. Among supernatant proteins a cellulosomal GH48 hydrolase, a rubrerthyrin-like protein and a protein with type IV pili N-terminal domain were the most strongly up-regulated in 007C cultures grown on Avicel compared with cellobiose. Strain 007S also showed substrate-related changes, but supernatant expression of the Pil protein and rubrerythrin in particular were markedly lower in 007S than in 007C during growth on Avicel. Conclusions/Significance This study provides new information on the extracellular proteome of R. flavefaciens and its regulation in response to different growth substrates. Furthermore it suggests that the cotton cellulose non-degrading strain (007S) has altered regulation of multiple proteins that may be required for breakdown of cotton cellulose. One of these, the type IV pilus was previously shown to play a role in adhesion to cellulose in R. albus, and a related pilin protein was identified here for the first time as a major extracellular protein in R. flavefaciens. PMID:23750253

  17. A Decameter Stationary Type IV Burst in Imaging Observations on 2014 September 6

    NASA Astrophysics Data System (ADS)

    Koval, Artem; Stanislavsky, Aleksander; Chen, Yao; Feng, Shiwei; Konovalenko, Aleksander; Volvach, Yaroslav

    2016-08-01

    First-of-its-kind radio imaging of a decameter solar stationary type IV radio burst has been presented in this paper. On 2014 September 6 the observations of type IV burst radio emission were carried out with the two-dimensional heliograph based on the Ukrainian T-shaped radio telescope (UTR-2), together with other telescope arrays. Starting at ˜09:55 UT and for ˜3 hr, the radio emission was kept within the observational session of UTR-2. The interesting observation covered the full evolution of this burst, “from birth to death.” During the event lifetime, two C-class solar X-ray flares with peak times 11:29 UT and 12:24 UT took place. The time profile of this burst in radio has a double-humped shape that can be explained by injection of energetic electrons, accelerated by the two flares, into the burst source. According to the heliographic observations, we suggest that the burst source was confined within a high coronal loop, which was part of a relatively slow coronal mass ejection. The latter has been developed for several hours before the onset of the event. Through analysis of about 1.5 × 106 heliograms (3700 temporal frames with 4096 images in each frame that correspond to the number of frequency channels), the radio burst source imaging shows a fascinating dynamical evolution. Both space-based (GOES, SDO, SOHO, STEREO) data and various ground-based instrumentation (ORFEES, NDA, RSTO, NRH) records have been used for this study.

  18. Neisseria meningitidis Type IV Pili Composed of Sequence Invariable Pilins Are Masked by Multisite Glycosylation

    PubMed Central

    Gault, Joseph; Ferber, Mathias; Machata, Silke; Imhaus, Anne-Flore; Malosse, Christian; Charles-Orszag, Arthur; Millien, Corinne; Bouvier, Guillaume; Bardiaux, Benjamin; Péhau-Arnaudet, Gérard; Klinge, Kelly; Podglajen, Isabelle; Ploy, Marie Cécile; Seifert, H. Steven; Nilges, Michael; Chamot-Rooke, Julia; Duménil, Guillaume

    2015-01-01

    The ability of pathogens to cause disease depends on their aptitude to escape the immune system. Type IV pili are extracellular filamentous virulence factors composed of pilin monomers and frequently expressed by bacterial pathogens. As such they are major targets for the host immune system. In the human pathogen Neisseria meningitidis, strains expressing class I pilins contain a genetic recombination system that promotes variation of the pilin sequence and is thought to aid immune escape. However, numerous hypervirulent clinical isolates express class II pilins that lack this property. This raises the question of how they evade immunity targeting type IV pili. As glycosylation is a possible source of antigenic variation it was investigated using top-down mass spectrometry to provide the highest molecular precision on the modified proteins. Unlike class I pilins that carry a single glycan, we found that class II pilins display up to 5 glycosylation sites per monomer on the pilus surface. Swapping of pilin class and genetic background shows that the pilin primary structure determines multisite glycosylation while the genetic background determines the nature of the glycans. Absence of glycosylation in class II pilins affects pilus biogenesis or enhances pilus-dependent aggregation in a strain specific fashion highlighting the extensive functional impact of multisite glycosylation. Finally, molecular modeling shows that glycans cover the surface of class II pilins and strongly decrease antibody access to the polypeptide chain. This strongly supports a model where strains expressing class II pilins evade the immune system by changing their sugar structure rather than pilin primary structure. Overall these results show that sequence invariable class II pilins are cloaked in glycans with extensive functional and immunological consequences. PMID:26367394

  19. AtlasT4SS: A curated database for type IV secretion systems

    PubMed Central

    2012-01-01

    Background The type IV secretion system (T4SS) can be classified as a large family of macromolecule transporter systems, divided into three recognized sub-families, according to the well-known functions. The major sub-family is the conjugation system, which allows transfer of genetic material, such as a nucleoprotein, via cell contact among bacteria. Also, the conjugation system can transfer genetic material from bacteria to eukaryotic cells; such is the case with the T-DNA transfer of Agrobacterium tumefaciens to host plant cells. The system of effector protein transport constitutes the second sub-family, and the third one corresponds to the DNA uptake/release system. Genome analyses have revealed numerous T4SS in Bacteria and Archaea. The purpose of this work was to organize, classify, and integrate the T4SS data into a single database, called AtlasT4SS - the first public database devoted exclusively to this prokaryotic secretion system. Description The AtlasT4SS is a manual curated database that describes a large number of proteins related to the type IV secretion system reported so far in Gram-negative and Gram-positive bacteria, as well as in Archaea. The database was created using the RDBMS MySQL and the Catalyst Framework based in the Perl programming language and using the Model-View-Controller (MVC) design pattern for Web. The current version holds a comprehensive collection of 1,617 T4SS proteins from 58 Bacteria (49 Gram-negative and 9 Gram-Positive), one Archaea and 11 plasmids. By applying the bi-directional best hit (BBH) relationship in pairwise genome comparison, it was possible to obtain a core set of 134 clusters of orthologous genes encoding T4SS proteins. Conclusions In our database we present one way of classifying orthologous groups of T4SSs in a hierarchical classification scheme with three levels. The first level comprises four classes that are based on the organization of genetic determinants, shared homologies, and evolutionary

  20. Type IV collagen is an activating ligand for the adhesion G protein-coupled receptor GPR126.

    PubMed

    Paavola, Kevin J; Sidik, Harwin; Zuchero, J Bradley; Eckart, Michael; Talbot, William S

    2014-08-12

    GPR126 is an orphan heterotrimeric guanine nucleotide-binding protein (G protein)-coupled receptor (GPCR) that is essential for the development of diverse organs. We found that type IV collagen, a major constituent of the basement membrane, binds to Gpr126 and activates its signaling function. Type IV collagen stimulated the production of cyclic adenosine monophosphate in rodent Schwann cells, which require Gpr126 activity to differentiate, and in human embryonic kidney (HEK) 293 cells expressing exogenous Gpr126. Type IV collagen specifically bound to the extracellular amino-terminal region of Gpr126 containing the CUB (complement, Uegf, Bmp1) and pentraxin domains. Gpr126 derivatives lacking the entire amino-terminal region were constitutively active, suggesting that this region inhibits signaling and that ligand binding relieves this inhibition to stimulate receptor activity. A new zebrafish mutation that truncates Gpr126 after the CUB and pentraxin domains disrupted development of peripheral nerves and the inner ear. Thus, our findings identify type IV collagen as an activating ligand for GPR126, define its mechanism of activation, and highlight a previously unrecognized signaling function of type IV collagen in basement membranes.

  1. Role of 17 beta-estradiol on type IV collagen fibers volumetric density in the basement membrane of bladder wall.

    PubMed

    de Fraga, Rogerio; Dambros, Miriam; Miyaoka, Ricardo; Riccetto, Cássio Luís Zanettini; Palma, Paulo César Rodrigues

    2007-10-01

    The authors quantified the type IV collagen fibers volumetric density in the basement membrane of bladder wall of ovariectomized rats with and without estradiol replacement. This study was conducted on 40 Wistar rats (3 months old) randomly divided in 4 groups: group 1, remained intact (control); group 2, submitted to bilateral oophorectomy and daily replacement 4 weeks later of 17 beta-estradiol for 12 weeks; group 3, sham operated and daily replacement 4 weeks later of sesame oil for 12 weeks; and group 4, submitted to bilateral oophorectomy and killed after 12 weeks. It was used in immunohistochemistry evaluation using type IV collagen polyclonal antibody to stain the fibers on paraffin rat bladder sections. The M-42 stereological grid system was used to analyze the fibers. Ovariectomy had an increase effect on the volumetric density of the type IV collagen fibers in the basement membrane of rat bladder wall. Estradiol replacement in castrated animals demonstrated a significative difference in the stereological parameters when compared to the castrated group without hormonal replacement. Surgical castration performed on rats induced an increasing volumetric density of type IV collagen fibers in the basement membrane of rats bladder wall and the estradiol treatment had a significant effect in keeping a low volumetric density of type IV collagen fibers in the basement membrane of rats bladder wall.

  2. Bifurcation of Codimension 3 in a Predator-Prey System of Leslie Type with Simplified Holling Type IV Functional Response

    NASA Astrophysics Data System (ADS)

    Huang, Jicai; Xia, Xiaojing; Zhang, Xinan; Ruan, Shigui

    It was shown in [Li & Xiao, 2007] that in a predator-prey model of Leslie type with simplified Holling type IV functional response some complex bifurcations can occur simultaneously for some values of parameters, such as codimension 1 subcritical Hopf bifurcation and codimension 2 Bogdanov-Takens bifurcation. In this paper, we show that for the same model there exists a unique degenerate positive equilibrium which is a degenerate Bogdanov-Takens singularity (focus case) of codimension 3 for other values of parameters. We prove that the model exhibits degenerate focus type Bogdanov-Takens bifurcation of codimension 3 around the unique degenerate positive equilibrium. Numerical simulations, including the coexistence of three hyperbolic positive equilibria, two limit cycles, bistability states (one stable equilibrium and one stable limit cycle, or two stable equilibria), tristability states (two stable equilibria and one stable limit cycle), a stable limit cycle enclosing a homoclinic loop, a homoclinic loop enclosing an unstable limit cycle, or a stable limit cycle enclosing three unstable hyperbolic positive equilibria for various parameter values, confirm the theoretical results.

  3. Immunohistochemical expression of collagen type IV antibody in the articular disc of the temporomandibular joint of human fetuses.

    PubMed

    de Moraes, Luís Otávio Carvalho; Lodi, Fábio Redivo; Gomes, Thiago Simão; Marques, Sergio Ricardo; Fernandes Junior, João Antão; Oshima, Celina Tizuko Fijiyama; Alonso, Luís Garcia

    2008-01-01

    The objective of this paper was to study the morphology of the articular disc and analyze the immunohistochemical expression of the marker of type IV collagen in the articular disc of the temporomandibular joint (TMJ) of human fetuses of different gestational ages. Twenty TMJ from human fetuses aging from 21 to 24 weeks of intrauterine life were studied. The TMJ were supplied by the Federal University of Uberaba. The ages of the fetuses were determined by measuring the crown-rump length (CRL). Macroscopically, the fetuses were fixed in a formalin solution at 10% and dissected by removing the skin and the subcutaneous tissue, exposing the deep structures. An immunohistochemical marker of type IV collagen was used in order to characterize the presence of blood vessels in the central region of the temporomandibular joint disc. Analysis of the immunohistochemical marker of type IV collagen showed the presence of blood vessels in the central region of the temporomandibular disc in human fetuses.

  4. Structural characterization of ribosome recruitment and translocation by type IV IRES

    PubMed Central

    Murray, Jason; Savva, Christos G; Shin, Byung-Sik; Dever, Thomas E; Ramakrishnan, V; Fernández, Israel S

    2016-01-01

    Viral mRNA sequences with a type IV IRES are able to initiate translation without any host initiation factors. Initial recruitment of the small ribosomal subunit as well as two translocation steps before the first peptidyl transfer are essential for the initiation of translation by these mRNAs. Using electron cryomicroscopy (cryo-EM) we have structurally characterized at high resolution how the Cricket Paralysis Virus Internal Ribosomal Entry Site (CrPV-IRES) binds the small ribosomal subunit (40S) and the translocation intermediate stabilized by elongation factor 2 (eEF2). The CrPV-IRES restricts the otherwise flexible 40S head to a conformation compatible with binding the large ribosomal subunit (60S). Once the 60S is recruited, the binary CrPV-IRES/80S complex oscillates between canonical and rotated states (Fernández et al., 2014; Koh et al., 2014), as seen for pre-translocation complexes with tRNAs. Elongation factor eEF2 with a GTP analog stabilizes the ribosome-IRES complex in a rotated state with an extra ~3 degrees of rotation. Key residues in domain IV of eEF2 interact with pseudoknot I (PKI) of the CrPV-IRES stabilizing it in a conformation reminiscent of a hybrid tRNA state. The structure explains how diphthamide, a eukaryotic and archaeal specific post-translational modification of a histidine residue of eEF2, is involved in translocation. DOI: http://dx.doi.org/10.7554/eLife.13567.001 PMID:27159451

  5. Community-Associated Methicillin-Resistant Staphylococcus aureus Clonal Complex 80 Type IV (CC80-MRSA-IV) Isolated from the Middle East: A Heterogeneous Expanding Clonal Lineage

    PubMed Central

    Harastani, Houda H.; Tokajian, Sima T.

    2014-01-01

    Background The emergence of community-associated methicillin resistant Staphylococcus aureus (CA-MRSA) has caused a change in MRSA epidemiology worldwide. In the Middle East, the persistent spread of CA-MRSA isolates that were associated with multilocus sequence type (MLST) clonal complex 80 and with staphylococcal cassette chromosome mec (SCCmec) type IV (CC80-MRSA-IV), calls for novel approaches for infection control that would limit its spread. Methodology/Principal Findings In this study, the epidemiology of CC80-MRSA-IV was investigated in Jordan and Lebanon retrospectively covering the period from 2000 to 2011. Ninety-four S. aureus isolates, 63 (67%) collected from Lebanon and 31 (33%) collected from Jordan were included in this study. More than half of the isolates (56%) were associated with skin and soft tissue infections (SSTIs), and 73 (78%) were Panton-Valentine Leukocidin (PVL) positive. Majority of the isolates (84%) carried the gene for exofoliative toxin d (etd), 19% had the Toxic Shock Syndrome Toxin-1 gene (tst), and seven isolates from Jordan had a rare combination being positive for both tst and PVL genes. spa typing showed the prevalence of type t044 (85%) and pulsed-field gel electrophoresis (PFGE) recognized 21 different patterns. Antimicrobial susceptibility testing showed the prevalence (36%) of a unique resistant profile, which included resistance to streptomycin, kanamycin, and fusidic acid (SKF profile). Conclusions The genetic diversity among the CC80 isolates observed in this study poses an additional challenge to infection control of CA-MRSA epidemics. CA-MRSA related to ST80 in the Middle East was distinguished in this study from the ones described in other countries. Genetic diversity observed, which may be due to mutations and differences in the antibiotic regimens between countries may have led to the development of heterogeneous strains. Hence, it is difficult to maintain “the European CA-MRSA clone” as a uniform clone and it

  6. Basement Membrane Type IV Collagen and Laminin: An Overview of Their Biology and Value as Fibrosis Biomarkers of Liver Disease.

    PubMed

    Mak, Ki M; Mei, Rena

    2017-02-10

    Basement membranes provide structural support to epithelium, endothelium, muscles, fat cells, Schwann cells, and axons. Basement membranes are multifunctional: they modulate cellular behavior, regulate organogenesis, promote tissue repair, form a barrier to filtration and tumor metastasis, bind growth factors, and mediate angiogenesis. All basement membranes contain type IV collagen (Col IV), laminin, nidogen, and perlecan. Col IV and laminin self-assemble into two independent supramolecular networks that are linked to nidogen and perlecan to form a morphological discernable basement membrane/basal lamina. The triple helical region, 7S domain and NCI domain of Col IV, laminin and laminin fragment P1 have been evaluated as noninvasive fibrosis biomarkers of alcoholic liver disease, viral hepatitis, and nonalcoholic fatty liver disease. Elevated serum Col IV and laminin are related to degrees of fibrosis and severity of hepatitis, and may reflect hepatic basement membrane metabolism. But the serum assays have not been linked to disclosing the anatomical sites and lobular distribution of perisinusoidal basement membrane formation in the liver. Hepatic sinusoids normally lack a basement membrane, although Col IV is a normal matrix component of the space of Disse. In liver disease, laminin deposits in the space of Disse and codistributes with Col IV, forming a perisinusoidal basement membrane. Concomitantly, the sinusoidal endothelium loses its fenestrae and is transformed into vascular type endothelium. These changes lead to capillarization of hepatic sinusoids, a significant pathology that impairs hepatic function. Accordingly, codistribution of Col IV and laminin serves as histochemical marker of perisinusoidal basement membrane formation in liver disease. Anat Rec, 2017. © 2017 Wiley Periodicals, Inc.

  7. AN ASSESSMENT OF THE SERVICE HISTORY AND CORROSION SUSCEPTIBILITY OF TYPE IV WASTE TANKS

    SciTech Connect

    Wiersma, B

    2008-09-18

    Type IV waste tanks were designed and built to store waste that does not require auxiliary cooling. Each Type IV tank is a single-shell tank constructed of a steel-lined pre-stressed concrete tank in the form of a vertical cylinder with a concrete domed roof. There are four such tanks in F-area, Tanks 17-20F, and four in H-Area, Tanks 21-24H. Leak sites were discovered in the liners for Tanks 19 and 20F in the 1980's. Although these leaks were visually observed, the investigation to determine the mechanism by which the leaks had occurred was not completed at that time. Therefore, a concern was raised that the same mechanism which caused the leak sites in the Tanks in F-area may also be operable in the H-Area tanks. Data from the construction of the tanks (i.e., certified mill test reports for the steel, no stress-relief), the service history (i.e., waste sample data, temperature data), laboratory tests on actual wastes and simulants (i.e., electrochemical testing), and the results of the visual inspections were reviewed. The following observations and conclusions were made: (1) Comparison of the compositional and microstructural features indicate that the A212 material utilized for construction of the H-Area tanks are far more resistant to SCC than the A285 materials used for construction of the F-Area tanks. (2) A review of the materials of construction, temperature history, service histories concluded that F-Area tanks likely failed by caustic stress corrosion cracking. (3) The environment in the F-Area tanks was more aggressive than that experienced by the H-Area tanks. (4) Based on a review of the service history, the H-Area tanks have not been exposed to an environment that would render the tanks susceptible to either nitrate stress corrosion cracking (i.e., the cause of failures in the Type I and II tanks) or caustic stress corrosion cracking. (5) Due to the very dilute and uninhibited solutions that have been stored in Tank 23H, vapor space corrosion has

  8. Hereditary Sensory and Autonomic Neuropathy Type IV in 9 Year Old Boy: A Case Report

    PubMed Central

    AZADVARI, Mohaddeseh; EMAMI RAZAVI, Seyedeh Zahra; KAZEMI, Shahrbanoo

    2016-01-01

    Objective The Hereditary Sensory and Autonomic neuropathy (HSAN) is a rare group of neuropathies that affects the Sensory and Autonomic nervous system. The patients do not have the ability of sensing different sensations such as pain and temperature, which tends to lead to different injuries. In addition, due to autonomic involvement, the patients suffer from fluctuation in body temperature periodically and lack of precipitation. HSAN is divided into 5 types according to the age of onset, clinical features, and inheritance. Our case was a 9-yr old boy from cousin parents. He had some developmental delay and history of recurrent fever and convulsion in the first year of his life. Gradually, other symptoms added to patient’ feature such as multiple painless skin ulcers, tooth loss, destruction of toes and fingers. In electrodiagnostic study, we found decreased amplitude of sensory nerves, while the other studies were normal. Laboratory test and imaging studies were also normal. All clinical and paraclinical findings were in favor of HSAN type IV. There is no cure for such patients; as a result, these patients and their families need receiving appropriate education and timely rehabilitation services. PMID:27247588

  9. Computational prediction of type III and IV secreted effectors in Gram-negative bacteria

    SciTech Connect

    McDermott, Jason E.; Corrigan, Abigail L.; Peterson, Elena S.; Oehmen, Christopher S.; Niemann, George; Cambronne, Eric; Sharp, Danna; Adkins, Joshua N.; Samudrala, Ram; Heffron, Fred

    2011-01-01

    In this review, we provide an overview of the methods employed by four recent papers that described novel methods for computational prediction of secreted effectors from type III and IV secretion systems in Gram-negative bacteria. The results of the studies in terms of performance at accurately predicting secreted effectors and similarities found between secretion signals that may reflect biologically relevant features for recognition. We discuss the web-based tools for secreted effector prediction described in these studies and announce the availability of our tool, the SIEVEserver (http://www.biopilot.org). Finally, we assess the accuracy of the three type III effector prediction methods on a small set of proteins not known prior to the development of these tools that we have recently discovered and validated using both experimental and computational approaches. Our comparison shows that all methods use similar approaches and, in general arrive at similar conclusions. We discuss the possibility of an order-dependent motif in the secretion signal, which was a point of disagreement in the studies. Our results show that there may be classes of effectors in which the signal has a loosely defined motif, and others in which secretion is dependent only on compositional biases. Computational prediction of secreted effectors from protein sequences represents an important step toward better understanding the interaction between pathogens and hosts.

  10. c-Type Cytochrome-Dependent Formation of U(IV) Nanoparticles by Shewanella oneidensis

    SciTech Connect

    Marshall, Matthew J.; Beliaev, Alex S.; Dohnalkova, Alice; Kennedy, David W.; Shi, Liang; Wang, Zheming; Boyanov, Maxim I.; Lai, Barry; Kemner, Kenneth M.; Mclean, Jeffrey S.; Reed, Samantha B.; Culley, David E.; Bailey, Vanessa L.; Simonson, Cody J.; Saffarini, Daad; Romine, Margaret F.; Zachara, John M.; Fredrickson, Jim K.

    2006-08-08

    Modern approaches for bioremediation of radionuclide contaminated environments are based on the ability of microorganisms to effectively catalyze changes in the oxidation states of metals that in turn influence their solubility. Although microbial metal reduction has been identified as an effective means for immobilizing highly-soluble uranium(VI) complexes in situ, the biomolecular mechanisms of U(VI) reduction are not well understood. Here, we show that c-type cytochromes of a dissimilatory metal reducing bacterium, Shewanella oneidensis MR-1 are essential for the reduction of U(VI) and formation of extracelluar UO2 nanoparticles. In particular, the outer membrane (OM) decaheme cytochrome MtrC, previously implicated in Mn(IV) and Fe(III) reduction, directly transferred electrons to U(VI). Additionally, deletions of mtrC and/or omcA significantly affected the in vivo U(VI) reduction rate relative to wild type MR-1. Similar to the wild type, the mutants accumulated UO2 nanoparticles extracellularly to high densities in association with an exopolymeric substance (EPS). In wild type cells, this UO2-EPS matrix exhibited glycocalyx-like properties, contained multiple elements of the OM, polysaccharide, and heme containing proteins. Using a novel combination of methods including synchrotron-based X-ray fluorescence microscopy and high resolution immune-electron microscopy, we demonstrate a close association of the extracellular UO2 nanoparticles with MtrC and OmcA. This is the first study to directly localize the OM-associated cytochromes with EPS, which contains biogenic UO2 nanoparticles. In the environment, such association of UO2 nanoparticles with biopolymers may exert a strong influence on subsequent behavior including susceptibility to oxidation by O2 or transport in soils and sediments.

  11. Alglucosidase alfa treatment alleviates liver disease in a mouse model of glycogen storage disease type IV.

    PubMed

    Yi, Haiqing; Gao, Fengqin; Austin, Stephanie; Kishnani, Priya S; Sun, Baodong

    2016-12-01

    Patients with progressive hepatic form of GSD IV often die of liver failure in early childhood. We tested the feasibility of using recombinant human acid-α glucosidase (rhGAA) for treating GSD IV. Weekly intravenously injection of rhGAA at 40 mg/kg for 4 weeks significantly reduced hepatic glycogen accumulation, lowered liver/body weight ratio, and reduced plasma ALP and ALT activities in GSD IV mice. Our data suggests that rhGAA is a potential therapy for GSD IV.

  12. Using General Anesthesia plus Muscle Relaxant in a Patient with Spinal Muscular Atrophy Type IV: A Case Report

    PubMed Central

    Liu, Xiu-Fen; Wang, Dong-Xin; Ma, Daqing

    2011-01-01

    Spinal muscular atrophy (SMA) is a rare genetic disease characterized by degeneration of spinal cord motor neurons, which results in hypotonia and muscle weakness. Patients with type IV SMA often have onset of weakness from adulthood. Anesthetic management is often difficult in these patients as a result of muscle weakness and hypersensitivity to neuromuscular blocking agents as shown by (Lunn and Wang; 2008, Simic; 2008, and Cifuentes-Diaz et al.; 2002). Herein we report a case of anesthetic management of a patient with SMA type IV for mammectomy and review some other cases of SMA patients receiving different kinds of anesthesia. PMID:22606392

  13. Different patterns of postprandial lipoprotein metabolism in normal, type IIa, type III, and type IV hyperlipoproteinemic individuals. Effects of treatment with cholestyramine and gemfibrozil.

    PubMed Central

    Weintraub, M S; Eisenberg, S; Breslow, J L

    1987-01-01

    To study exogenous fat metabolism, we used the vitamin A-fat loading test, which specifically labels intestinally derived lipoproteins with retinyl palmitate (RP). Postprandial RP concentrations were followed in total plasma, and chylomicron (Sf greater than 1,000) and nonchylomicron (Sf less than 1,000) fractions. In normal subjects postprandial lipoproteins were present for more than 14 h, and chylomicron levels correlated inversely with lipoprotein lipase activity and fasting high density lipoprotein (HDL) cholesterol levels and nonchylomicron levels correlated inversely with hepatic triglyceride lipase activity. The main abnormality in type IV patients was a 5.6-fold increase in the chylomicron fraction, whereas in type III patients it was a 6.4-fold increase in nonchylomicrons. Type IIa patients had abnormally low chylomicron fractions. In type IV patients gemfibrozil decreased, whereas in type IIa patients cholestyramine increased the chylomicron fraction 66 and 88%, respectively. This study demonstrates an unexpectedly large magnitude and long duration of postprandial lipemia in normal subjects and patients. These particles are potentially atherogenic, and their role in human atherosclerosis warrants further study. PMID:3470306

  14. Differences in type II, IV, V and VI adenylyl cyclase isoform expression between rat preadipocytes and adipocytes.

    PubMed

    Serazin-Leroy, V; Morot, M; de Mazancourt, P; Giudicelli, Y

    2001-11-26

    Adenylyl cyclase catalytic activity is low in preadipocyte membranes when compared to adipocytes. Under conditions promoting inhibition of adipocyte adenylyl cyclase activity by Gpp(NH)p, a stable GTP analog, a paradoxical increase in preadipocyte adenylyl cyclase activity was obtained. In order to explain this contradiction, expression of types II, IV, V and VI adenylyl cyclase isoforms was compared in adipocytes and undifferentiated preadipocytes both by western blots and by a semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) assay. Type II, IV, V and VI mRNAs and proteins were present in both adipocytes and preadipocytes. However, in undifferentiated preadipocytes, expression of type II mRNA and protein were significantly higher whereas expression of type IV, V and VI adenylyl cyclase mRNAs and proteins were significantly weaker than in adipocytes. In late differentiated preadipocytes, the adenylyl cyclase subtype mRNA expression pattern was intermediary between the undifferentiated and the full differentiation states except for type IV which remained weakly expressed. Moreover, one of the representative regulators of G-protein signaling (RGS protein), RGS4, was less expressed in undifferentiated preadipocyte membranes and cytosol extracts, which contrasts with adipocytes where RGS4 is clearly expressed. Thus, the preferential expression of type II adenylyl cyclase (G(betagamma) subunit-stimulated) in preadipocytes might explain why Gpp(NH)p elicits stimulation of adenylyl cyclase under conditions designed to promote inhibition. Conversely, the preferential expression of type V and VI adenylyl cyclases and the slightly higher expression of type IV adenylyl cyclase in adipocytes could contribute to explain the elevated total catalytic activity observed in mature fat cells compared to their precursor cells.

  15. Tibial lengthening for unilateral Crowe type-IV developmental dysplasia of the hip

    PubMed Central

    Wan, Jun; Zhang, Xiang-Sheng; Ling, Lin; Fan, Jing; Li, Zhi-Hong

    2014-01-01

    Background: Developmental dysplasia of the hip (DDH) is associated with chronic pain and limping which especially has a negative impact on the patients’ daily activities, body image, and self-esteem. Although total hip arthroplasty remains the first choice for treatment of DDH in adults, minimally invasive alternative approaches are being increasingly favored both by the surgeon and the patients with severe DDH. This study aimed to evaluate the outcome of these patients treated with a mono-lateral external fixator-based tibial lengthening procedure. Materials and Methods: During the period of month between June 1999 and January 2006, 13 (mean ages 20.8 years) adult patients with unilateral Crowe type-IV DDH were treated by tibial lengthening using a mono-lateral external fixator over an intramedullary nail. Bone healing, infection, gait correction and improvement in body image were assessed during postoperative followup. Patients’ overall health status at the end of followup was assessed using the short form-36 (SF-36) health survey. Results: Patients were followed up for an average of 7.3 years. Successful bone healing was observed in all 13 patients and no further surgeries were indicated. A mean external fixation index of 12.4 days/cm was achieved. Bone formation fell in good to excellent categories with a mean consolidation index of 50.1 days/cm. Pin-tract infections were observed in two patients. The degree of limping was reduced from severe or moderate preoperatively to mild postoperatively. Neither equinus deformity nor painful degenerative osteoarthritis and hip dysfunction were observed in any of the patients studied. The SF-36 questionnaire survey showed that all patients were satisfied with their outcomes. Conclusions: Tibial lengthening may effectively correct gait and satisfactorily improve body image in young patients with unilateral Crowe type-IV DDH. Mono-lateral external fixator allows for accelerated postoperative rehabilitation and optimal

  16. Cationic Group-IV pincer-type complexes for polymerization and hydroamination catalysis.

    PubMed

    Luconi, Lapo; Klosin, Jerzy; Smith, Austin J; Germain, Stéphane; Schulz, Emmanuelle; Hannedouche, Jérôme; Giambastiani, Giuliano

    2014-03-21

    Neutral Zr(IV) and Hf(IV) dimethyl complexes stabilized by unsymmetrical dianionic {N,C,N'} pincer ligands have been prepared from their corresponding bis-amido complexes upon treatment with AlMe₃. Their structure consists of a central ó-bonded aryl donor group (C) capable of forming robust M-C bonds with the metal center, enforced by the synergic effect of both the coordination of peripheral donor groups (N) and the chelating rigid structure of the {N,C,N} ligand framework. Such a combination translates into systems having a unique balance between stability and reactivity. These Zr(IV) and Hf(IV) dimethyl complexes were converted in situ into cationic species [M(IV){N⁻,C⁻,N}Me][B(C₆F₅)₄] which are active catalysts for the room temperature (r.t.) intramolecular hydroamination/cyclization of primary and secondary aminoalkenes as well as for the high temperature ethylene-1-octene copolymerizations.

  17. Influence of direct laser fabrication implant topography on type IV bone: a histomorphometric study in humans.

    PubMed

    Shibli, Jamil Awad; Mangano, Carlo; D'avila, Susana; Piattelli, Adriano; Pecora, Gabriele E; Mangano, Francesco; Onuma, Tatiana; Cardoso, Luciana A; Ferrari, Daniel Sanchez; Aguiar, Kelly C; Iezzi, Giovanna

    2010-05-01

    The aim of this histologic study was to evaluate the influence of the direct laser fabrication (DFL) surface topography on bone-to-implant contact (BIC%), on bone density in the threaded area (BA%) as well as bone density outside the threaded area (BD%) in type IV bone after 8 weeks of unloaded healing. Thirty patients (mean age 51.34 +/- 3.06 years) received 1 micro-implant (2.5-mm diameter and 6-mm length) each during conventional implant surgery in the posterior maxilla. Thirty micro-implants with three topographies were evaluated: 10 machined (cpTi); 10 sandblasted and acid etched surface (SAE) and 10 DFL micro-implants. After 8 weeks, the micro-implants and the surrounding tissue were removed and prepared for histomorphometric analysis. Four micro-implants (2 cpTi, 1 SAE and 1DLF) showed no osseointegration after the healing period. Histometric evaluation indicated that the mean BIC% was higher for the DFL and SAE surfaces (p = 0.0002). The BA% was higher for the DFL surface, although there was no difference with the SAE surface. The BD% was similar for all topographies (p > 0.05). Data suggest that the DFL and SAE surfaces presented a higher bone-to-implant contact rate compared with cpTi surfaces under unloaded conditions, after a healing period of 8 weeks.

  18. Crystal structure of the type IV secretion system component CagX from Helicobacter pylori.

    PubMed

    Zhang, Jin; Fan, Fei; Zhao, Yanhe; Sun, Lifang; Liu, Yadan; Keegan, Ronan M; Isupov, Michail N; Wu, Yunkun

    2017-03-01

    Helicobacter pylori, a Gram-negative bacterial pathogen prevalent in the human population, is the causative agent of severe gastric diseases. An H. pylori type IV secretion (T4S) system encoded by the cytotoxin-associated gene pathogenicity island (cagPAI) is responsible for communication with host cells. As a component of the cagPAI T4S system core complex, CagX plays an important role in virulence-protein translocation into the host cells. In this work, the crystal structure of the C-terminal domain of CagX (CagXct), which is a homologue of the VirB9 protein from the VirB/D4 T4S system, is presented. CagXct is only the second three-dimensional structure to be elucidated of a VirB9-like protein. Another homologue, TraO, which is encoded on the Escherichia coli conjugative plasmid pKM101, shares only 19% sequence identity with CagXct; however, there is a remarkable similarity in tertiary structure between these two β-sandwich protein domains. Most of the residues that are conserved between CagXct and TraO are located within the protein core and appear to be responsible for the preservation of this domain fold. The studies presented here will contribute to our understanding of different bacterial T4S systems.

  19. Flexibility of bacterial type IV pili determined using atomic force microscopy

    NASA Astrophysics Data System (ADS)

    Mogyoros, Josh; Lu, Shun; Harvey, Hanjeong; Burrows, Lori; Wickham, Robert; Dutcher, John

    Type IV pili (T4P) are very thin protein filaments extended and retracted from the surface of certain Gram-negative bacteria. Pili play a major role in processes such as adhesion, twitching motility and biofilm formation. We used atomic force microscopy (AFM) to perform force spectroscopy measurements on T4P of P. aeruginosa. Bacteria were adhered to the end of an AFM cantilever that was brought into contact with a substrate, allowing the pili to adhere. Force-separation curves were collected by retracting the cantilever, corresponding to the stretching of the T4P that was well described by the worm-like chain (WLC) model. Distinct peaks were observed in the distributions of the best-fit values of the persistence length Lp on two different surfaces, providing strong evidence for close-packed bundling of very flexible T4P. Surprisingly, the most prominent value of Lp ~ 1 nm is significantly less than the ~ 8 nm length of the PilA subunit. We have investigated this intriguing result by refining our protocol to combine AFM with fluorescence microscopy to isolate a single bacterium on a colloidal probe, as well as critically examining the applicability of the WLC model.

  20. Crystal structure of the type IV secretion system component CagX from Helicobacter pylori

    PubMed Central

    Zhang, Jin; Fan, Fei; Zhao, Yanhe; Sun, Lifang; Liu, Yadan; Wu, Yunkun

    2017-01-01

    Helicobacter pylori, a Gram-negative bacterial pathogen prevalent in the human population, is the causative agent of severe gastric diseases. An H. pylori type IV secretion (T4S) system encoded by the cytotoxin-associated gene pathogenicity island (cagPAI) is responsible for communication with host cells. As a component of the cagPAI T4S system core complex, CagX plays an important role in virulence-protein translocation into the host cells. In this work, the crystal structure of the C-terminal domain of CagX (CagXct), which is a homologue of the VirB9 protein from the VirB/D4 T4S system, is presented. CagXct is only the second three-dimensional structure to be elucidated of a VirB9-like protein. Another homologue, TraO, which is encoded on the Escherichia coli conjugative plasmid pKM101, shares only 19% sequence identity with CagXct; however, there is a remarkable similarity in tertiary structure between these two β-sandwich protein domains. Most of the residues that are conserved between CagXct and TraO are located within the protein core and appear to be responsible for the preservation of this domain fold. The studies presented here will contribute to our understanding of different bacterial T4S systems. PMID:28291753

  1. Preparation and characterization of resistant starch type IV nanoparticles through ultrasonication and miniemulsion cross-linking.

    PubMed

    Ding, Yongbo; Zheng, Jiong; Xia, Xuejuan; Ren, Tingyuan; Kan, Jianquan

    2016-05-05

    This study aimed to assess the properties of resistant starch type IV (chemically modified starch, RS4) prepared from a new and convenient synthesis route by using ultrasonication combined with water-in-oil miniemulsion cross-linking technique. A three-factor Box-Behnken design and optimization was used to minimize particle size through the developed RS4 nanoparticles. The predicted minimized Z-Avel (576.1nm) under the optimum conditions of the process variables (ultrasonic power, 214.57W; sonication time, 114.73min; and oil/water ratio, 10.54:1) was very close to the experimental value (651.0nm) determined in a batch experiment. After preparing the RS4 nanoparticles, morphological, physical, chemical, and functional properties were assessed. Results revealed that RS4 nanoparticle size reached about 600nm. Scanning electron microscopy images showed that ultrasonication induced notches and grooves on the surface. Under polarized light, the polarized cross was impaired. X-ray diffraction results revealed that the crystalline structure was disrupted. Smaller or no endotherms were exhibited in DSC analysis. In the FTIR graph, new peaks at 1532.91 and 1451.50cm(-1) were observed, and pasting properties were reduced. Amylose content, solubility, and SP increased, but RS content decreased. Anti-digestibility remained after ultrasonication. The prepared RS4 nanoparticles could be extensively used in biomedical applications and in the development of new medical materials.

  2. Crystal structure of Legionella pneumophila type IV secretion system effector LegAS4.

    PubMed

    Son, Jonghyeon; Jo, Chang Hwa; Murugan, Ravichandran N; Bang, Jeong Kyu; Hwang, Kwang Yeon; Lee, Woo Cheol

    2015-10-02

    The SET domain of LegAS4, a type IV secretion system effector of Legionella pneumophila, is a eukaryotic protein motif involved in histone methylation and epigenetic modulation. The SET domain of LegAS4 is involved in the modification of Lys4 of histone H3 (H3K4) in the nucleolus of the host cell, thereby enhancing heterochromatic rDNA transcription. Moreover, LegAS4 contains an ankyrin repeat domain of unknown function at its C-terminal region. Here, we report the crystal structure of LegAS4 in complex with S-adenosyl-l-methionine (SAM). Our data indicate that the ankyrin repeats interact extensively with the SET domain, especially with the SAM-binding amino acids, through conserved residues. Conserved surface analysis marks Glu159, Glu203, and Glu206 on the SET domain serve as candidate residues involved in interaction with the positively charged histone tail. Conserved surface residues on the ankyrin repeat domain surround a small pocket, which is suspected to serve as a binding site for an unknown ligand.

  3. Type IV pili of Acidithiobacillus ferrooxidans can transfer electrons from extracellular electron donors.

    PubMed

    Li, Yongquan; Li, Hongyu

    2014-03-01

    Studies on Acidithiobacillus ferrooxidans accepting electrons from Fe(II) have previously focused on cytochrome c. However, we have discovered that, besides cytochrome c, type IV pili (Tfp) can transfer electrons. Here, we report conduction by Tfp of A. ferrooxidans analyzed with a conducting-probe atomic force microscope (AFM). The results indicate that the Tfp of A. ferrooxidans are highly conductive. The genome sequence of A. ferrooxidans ATCC 23270 contains two genes, pilV and pilW, which code for pilin domain proteins with the conserved amino acids characteristic of Tfp. Multiple alignment analysis of the PilV and PilW (pilin) proteins indicated that pilV is the adhesin gene while pilW codes for the major protein element of Tfp. The likely function of Tfp is to complete the circuit between the cell surface and Fe(II) oxides. These results indicate that Tfp of A. ferrooxidans might serve as biological nanowires transferring electrons from the surface of Fe(II) oxides to the cell surface.

  4. Neisseria cinerea isolates can adhere to human epithelial cells by type IV pilus-independent mechanisms

    PubMed Central

    Wörmann, Mirka E.; Horien, Corey L.; Johnson, Errin; Liu, Guangyu; Aho, Ellen; Tang, Christoph M.

    2016-01-01

    In pathogenic Neisseria species the type IV pili (Tfp) are of primary importance in host–pathogen interactions. Tfp mediate initial bacterial attachment to cell surfaces and formation of microcolonies via pilus–pilus interactions. Based on genome analysis, many non-pathogenic Neisseria species are predicted to express Tfp, but aside from studies on Neisseria elongata, relatively little is known about the formation and function of pili in these organisms. Here, we have analysed pilin expression and the role of Tfp in Neisseria cinerea. This non-pathogenic species shares a close taxonomic relationship to the pathogen Neisseria meningitidis and also colonizes the human oropharyngeal cavity. Through analysis of non-pathogenic Neisseria genomes we identified two genes with homology to pilE, which encodes the major pilin of N. meningitidis. We show which of the two genes is required for Tfp expression in N. cinerea and that Tfp in this species are required for DNA competence, similar to other Neisseria. However, in contrast to the meningococcus, deletion of the pilin gene did not impact the association of N. cinerea to human epithelial cells, demonstrating that N. cinerea isolates can adhere to human epithelial cells by Tfp-independent mechanisms. PMID:26813911

  5. FREQUENCY DEPENDENCE OF POLARIZATION OF ZEBRA PATTERN IN TYPE-IV SOLAR RADIO BURSTS

    SciTech Connect

    Kaneda, Kazutaka; Misawa, H.; Tsuchiya, F.; Obara, T.; Iwai, K.

    2015-08-01

    We investigated the polarization characteristics of a zebra pattern (ZP) in a type-IV solar radio burst observed with AMATERAS on 2011 June 21 for the purpose of evaluating the generation processes of ZPs. Analyzing highly resolved spectral and polarization data revealed the frequency dependence of the degree of circular polarization and the delay between two polarized components for the first time. The degree of circular polarization was 50%–70% right-handed and it varied little as a function of frequency. Cross-correlation analysis determined that the left-handed circularly polarized component was delayed by 50–70 ms relative to the right-handed component over the entire frequency range of the ZP and this delay increased with the frequency. We examined the obtained polarization characteristics by using pre-existing ZP models and concluded that the ZP was generated by the double-plasma-resonance process. Our results suggest that the ZP emission was originally generated in a completely polarized state in the O-mode and was partly converted into the X-mode near the source. Subsequently, the difference between the group velocities of the O-mode and X-mode caused the temporal delay.

  6. Mechanism and function of type IV secretion during infection of the human host

    PubMed Central

    Gonzalez-Rivera, Christian; Bhatty, Minny; Christie, Peter J.

    2015-01-01

    Bacterial pathogens employ type IV secretion systems (T4SSs) for various purposes to aid in survival and proliferation in eukaryotic host. One large T4SS subfamily, the conjugation systems, confers a selective advantage to the invading pathogen in clinical settings through dissemination of antibiotic resistance genes and virulence traits. Besides their intrinsic importance as principle contributors to the emergence of multiply drug-resistant ‘superbugs’, detailed studies of these highly tractable systems have generated important new insights into the mode of action and architectures of paradigmatic T4SSs as a foundation for future efforts aimed at suppressing T4SS machine function. Over the past decade, extensive work on the second large T4SS subfamily, the effector translocators, has identified a myriad of mechanisms employed by pathogens to subvert, subdue, or bypass cellular processes and signaling pathways of the host cell. An overarching theme in the evolution of many effectors is that of molecular mimicry. These effectors carry domains similar to those of eukaryotic proteins and exert their effects through stealthy interdigitation of cellular pathways, often with the outcome not of inducing irreversible cell damage but rather of reversibly modulating cellular functions. This chapter summarizes the major developments for the actively studied pathogens with an emphasis on the structural and functional diversity of the T4SSs and the emerging common themes surrounding effector function in the human host. PMID:27337453

  7. Cellular localization and dynamics of the Mrr type IV restriction endonuclease of Escherichia coli

    PubMed Central

    Ghosh, Anirban; Passaris, Ioannis; Tesfazgi Mebrhatu, Mehari; Rocha, Susana; Vanoirbeek, Kristof; Hofkens, Johan; Aertsen, Abram

    2014-01-01

    In this study, we examined the intracellular whereabouts of Mrr, a cryptic type IV restriction endonuclease of Escherichia coli K12, in response to different conditions. In absence of stimuli triggering its activity, Mrr was found to be strongly associated with the nucleoid as a number of discrete foci, suggesting the presence of Mrr hotspots on the chromosome. Previously established elicitors of Mrr activity, such as exposure to high (hydrostatic) pressure (HP) or expression of the HhaII methyltransferase, both caused nucleoid condensation and an unexpected coalescence of Mrr foci. However, although the resulting Mrr/nucleoid complex was stable when triggered with HhaII, it tended to be only short-lived when elicited with HP. Moreover, HP-mediated activation of Mrr typically led to cellular blebbing, suggesting a link between chromosome and cellular integrity. Interestingly, Mrr variants could be isolated that were specifically compromised in either HhaII- or HP-dependent activation, underscoring a mechanistic difference in the way both triggers activate Mrr. In general, our results reveal that Mrr can take part in complex spatial distributions on the nucleoid and can be engaged in distinct modes of activity. PMID:24423871

  8. Characterization of mechanical properties of Type IV pili (Tfp) using atomic force microscopy

    NASA Astrophysics Data System (ADS)

    Lu, Shun; Harvey, Hanjeong; Burrows, Lori; Dutcher, John

    2010-03-01

    Type IV pili (Tfp) are thin flexible protein filaments that extend from the cell envelope of Gram- negative bacteria. The mechanical properties of Tfp are important since they allow bacteria to establish contact with various surfaces, as a first step in the formation of biofilms. We have used atomic force microscopy (AFM) for both imaging and pulling on Tfp filaments from hyper-piliated mutants of P. aeruginosa PAO1 that cannot retract their pili. Bacterial cells were adhered to AFM probes using poly-L-lysine. Force-extension curves were obtained for single pili and were fitted using the worm-like-chain (WLC) model. The statistical distributions obtained for pili contour length and persistence length were used to evaluate the mechanical properties of a single pilus and the biogenesis functions of different proteins (pilA, pilT) involved in its assembly and disassembly. The difference in rupture force between Tfp and different surfaces (mica, gold) was also measured. Our results shed new light on the role of mechanical forces that mediate bacteria-surface interactions and biofilm formation.

  9. Late onset pityriasis rubra pilaris type IV treated with low-dose acitretin.

    PubMed

    Mota, Fernando; Carvalho, Sandrina; Sanches, Madalena; Selores, Manuela

    2016-01-01

    Pityriasis rubra pilaris is a chronic inflammatory dermatosis of unknown etiology and great clinical variability. It has been divided into six categories. Types III, IV, and V occur in childhood and are distinguished by their clinical presentation, age of onset, and course. We report a 19-year-old male patient with a 2-week history of pruritic, scaling dermatosis of the hands, feet, elbows, and knees. He had no family history of skin disease. On physical examination, we observed circumscribed, reddish-orange, scaling plaques affecting the elbows and knees and a waxy palmoplantar keratoderma. The skin biopsy showed acanthosis, alternating orthokeratosis, parakeratosis, and follicular plugging suggestive of pityriasis rubra pilaris. The patient started treatment with oral acitretin, 25 mg every other day. The treatment was tolerated well, and after 6 months the lesions had resolved completely. Pityriasis rubra pilaris is a chronic papulosquamous disorder of unknown pathogenesis, characterized by reddish-orange scaly plaques, palmoplantar keratoderma, and keratotic follicular papules. There is still no consensus regarding the treatment, but therapeutic options include systemic retinoids, particularly acitretin in the recommended dose of 0.5 to 0.75 mg/kg/day. In our case, the patient was treated with a low-dose regimen of acitretin, which was effective and well tolerated.

  10. Cloning-independent markerless gene editing in Streptococcus sanguinis: novel insights in type IV pilus biology.

    PubMed

    Gurung, Ishwori; Berry, Jamie-Lee; Hall, Alexander M J; Pelicic, Vladimir

    2016-11-29

    Streptococcus sanguinis, a naturally competent opportunistic human pathogen, is a Gram-positive workhorse for genomics. It has recently emerged as a model for the study of type IV pili (Tfp)-exceptionally widespread and important prokaryotic filaments. To enhance genetic manipulation of Streptococcus sanguinis, we have developed a cloning-independent methodology, which uses a counterselectable marker and allows sophisticated markerless gene editing in situ We illustrate the utility of this methodology by answering several questions regarding Tfp biology by (i) deleting single or mutiple genes, (ii) altering specific bases in genes of interest, and (iii) engineering genes to encode proteins with appended affinity tags. We show that (i) the last six genes in the pil locus harbouring all the genes dedicated to Tfp biology play no role in piliation or Tfp-mediated motility, (ii) two highly conserved Asp residues are crucial for enzymatic activity of the prepilin peptidase PilD and (iii) that pilin subunits with a C-terminally appended hexa-histidine (6His) tag are still assembled into functional Tfp. The methodology for genetic manipulation we describe here should be broadly applicable.

  11. Neisseria cinerea isolates can adhere to human epithelial cells by type IV pilus-independent mechanisms.

    PubMed

    Wörmann, Mirka E; Horien, Corey L; Johnson, Errin; Liu, Guangyu; Aho, Ellen; Tang, Christoph M; Exley, Rachel M

    2016-03-01

    In pathogenic Neisseria species the type IV pili (Tfp) are of primary importance in host-pathogen interactions. Tfp mediate initial bacterial attachment to cell surfaces and formation of microcolonies via pilus-pilus interactions. Based on genome analysis, many non-pathogenic Neisseria species are predicted to express Tfp, but aside from studies on Neisseria elongata, relatively little is known about the formation and function of pili in these organisms. Here, we have analysed pilin expression and the role of Tfp in Neisseria cinerea. This non-pathogenic species shares a close taxonomic relationship to the pathogen Neisseria meningitidis and also colonizes the human oropharyngeal cavity. Through analysis of non-pathogenic Neisseria genomes we identified two genes with homology to pilE, which encodes the major pilin of N. meningitidis. We show which of the two genes is required for Tfp expression in N. cinerea and that Tfp in this species are required for DNA competence, similar to other Neisseria. However, in contrast to the meningococcus, deletion of the pilin gene did not impact the association of N. cinerea to human epithelial cells, demonstrating that N. cinerea isolates can adhere to human epithelial cells by Tfp-independent mechanisms.

  12. Ehlers-Danlos syndrome type IV is associated with a novel G984R COL3A1 mutation.

    PubMed

    Deng, Yao; Wei, Shijie; Hu, Shijun; Chen, Jinlan; Tan, Zhiping; Yang, Yifeng

    2015-07-01

    Ehlers-Danlos syndrome type IV is an autosomal dominant connective tissue disease. Mutations in COL3A1 have been identified to underlie this disease; however, to the best of our knowledge, no COL3A1 mutations have been reported in Ehlers-Danlos syndrome type IV patients with an ascending aortic aneurysm. In order to develop further understanding of COL3A1 mutations, an Ehlers-Danlos syndrome type IV patient diagnosed with an ascending aortic aneurysm and a familial history of sudden mortality was analyzed. Genomic DNA was isolated from the peripheral blood of the patient and his family members. All coding exons of eight aneurysm-related genes (FBN1, TGFBR1, TGFBR 2, MYH11, ACTA2, SLC2A10, NOTCH1 and COL3A1) were amplified using polymerase chain reaction (PCR). The PCR products were sequenced with the ABI 3100 Genetic Analyzer, and a mutation was predicted and identified using Polyphen-2, SIFT and Mutation Taster. The novel mutation was identified as c.2950G>A in COL3A1, which results in p.G984R. All three programs predicted this mutation to be deleterous to the protein function. The novel mutation identified in this study is potentially responsible for Ehlers-Danlos syndrome type IV in this patient, and expands the spectrum of COL3A1 mutations.

  13. Biochemical analysis of callus tissue in osteogenesis imperfecta type IV. Evidence for transient overmodification in collagen types I and III.

    PubMed Central

    Brenner, R E; Vetter, U; Nerlich, A; Wörsdorfer, O; Teller, W M; Müller, P K

    1989-01-01

    We analyzed tissue and cells from a stationary and a rapidly growing hyperplastic callus from a patient with osteogenesis imperfecta (OI) type IV and compared the results with those of compact bone and skin fibroblasts of an age-matched control. Collagen and protein contents per cell were low in the callus tissues and collagen I and III were overmodified as evidenced by an elevated level of hydroxylysine. The degree of lysyl hydroxylation was highest in those regions that appeared most immature by histological examination. Lysyl hydroxylation approached normal levels in collagen from the stationary callus and from the center of the growing callus. Overmodification of collagen was not seen in compact bone or cell cultures (neither skin fibroblasts nor callus cells) from the patient. Elevation of hydroxylysine in collagen from OI patients is generally attributed to mutations that delay triple helix formation. Our observations suggest that the varying degree of collagen modifications may occur in consequence of regulatory mechanisms during bone development and tissue repair. These mechanisms may be defective in some patients with OI as seen in this case with hyperplastic callus formation. Images PMID:2760218

  14. Pseudomonas aeruginosa Pore-Forming Exolysin and Type IV Pili Cooperate To Induce Host Cell Lysis.

    PubMed

    Basso, Pauline; Ragno, Michel; Elsen, Sylvie; Reboud, Emeline; Golovkine, Guillaume; Bouillot, Stephanie; Huber, Philippe; Lory, Stephen; Faudry, Eric; Attrée, Ina

    2017-01-24

    Clinical strains of Pseudomonas aeruginosa lacking the type III secretion system genes employ a toxin, exolysin (ExlA), for host cell membrane disruption. Here, we demonstrated that ExlA export requires a predicted outer membrane protein, ExlB, showing that ExlA and ExlB define a new active two-partner secretion (TPS) system of P. aeruginosa In addition to the TPS signals, ExlA harbors several distinct domains, which include one hemagglutinin domain, five arginine-glycine-aspartic acid (RGD) motifs, and a C-terminal region lacking any identifiable sequence motifs. However, this C-terminal region is important for the toxic activity, since its deletion abolishes host cell lysis. Using lipid vesicles and eukaryotic cells, including red blood cells, we demonstrated that ExlA has a pore-forming activity which precedes cell membrane disruption of nucleated cells. Finally, we developed a high-throughput cell-based live-dead assay and used it to screen a transposon mutant library of an ExlA-producing P. aeruginosa clinical strain for bacterial factors required for ExlA-mediated toxicity. The screen resulted in the identification of proteins involved in the formation of type IV pili as being required for ExlA to exert its cytotoxic activity by promoting close contact between bacteria and the host cell. These findings represent the first example of cooperation between a pore-forming toxin of the TPS family and surface appendages in host cell intoxication.

  15. Pseudomonas aeruginosa Pore-Forming Exolysin and Type IV Pili Cooperate To Induce Host Cell Lysis

    PubMed Central

    Basso, Pauline; Ragno, Michel; Elsen, Sylvie; Reboud, Emeline; Golovkine, Guillaume; Bouillot, Stephanie; Huber, Philippe; Lory, Stephen; Faudry, Eric

    2017-01-01

    ABSTRACT   Clinical strains of Pseudomonas aeruginosa lacking the type III secretion system genes employ a toxin, exolysin (ExlA), for host cell membrane disruption. Here, we demonstrated that ExlA export requires a predicted outer membrane protein, ExlB, showing that ExlA and ExlB define a new active two-partner secretion (TPS) system of P. aeruginosa. In addition to the TPS signals, ExlA harbors several distinct domains, which include one hemagglutinin domain, five arginine-glycine-aspartic acid (RGD) motifs, and a C-terminal region lacking any identifiable sequence motifs. However, this C-terminal region is important for the toxic activity, since its deletion abolishes host cell lysis. Using lipid vesicles and eukaryotic cells, including red blood cells, we demonstrated that ExlA has a pore-forming activity which precedes cell membrane disruption of nucleated cells. Finally, we developed a high-throughput cell-based live-dead assay and used it to screen a transposon mutant library of an ExlA-producing P. aeruginosa clinical strain for bacterial factors required for ExlA-mediated toxicity. The screen resulted in the identification of proteins involved in the formation of type IV pili as being required for ExlA to exert its cytotoxic activity by promoting close contact between bacteria and the host cell. These findings represent the first example of cooperation between a pore-forming toxin of the TPS family and surface appendages in host cell intoxication. PMID:28119472

  16. Coxiella burnetii Type IV Secretion-Dependent Recruitment of Macrophage Autophagosomes

    PubMed Central

    Winchell, Caylin G.; Graham, Joseph G.; Kurten, Richard C.

    2014-01-01

    Coxiella burnetii is an intracellular Gram-negative bacterium that causes human Q fever, a flu-like disease that can progress to chronic, life-threatening endocarditis. In humans, C. burnetii infects alveolar macrophages and promotes phagosomal fusion with autophagosomes and lysosomes, establishing a unique parasitophorous vacuole (PV) in which to replicate. The pathogen uses a Dot/Icm type IV secretion system (T4SS) to deliver effector proteins to the host cytoplasm, where they alter cellular processes to benefit the pathogen. The T4SS is required for PV expansion and prevention of apoptosis, but little else is known about the role of the system during intracellular growth. Recent reports suggest that C. burnetii actively recruits autophagosomes to the PV to deliver nutrients to the pathogen and provide membrane for the expanding vacuole. In this study, we examined the role of the T4SS in mediating PV interactions with autophagosomes. We found that the autophagy-related proteins LC3 and p62 localized to wild-type PV but not to T4SS mutant organism-containing phagosomes in human macrophage-like cells, primary human alveolar macrophages, and Chinese hamster ovary cells. However, while lipidated LC3 levels were elevated regardless of T4SS activity, no p62 turnover was observed during C. burnetii growth in macrophages, suggesting that the pathogen recruits preformed autophagosomes. When the T4SS was activated 24 h after infection, autophagosome recruitment ensued, indicating that autophagosome interactions are dispensable for initial PV maturation to a phagolysosome-like compartment but are involved in vacuole expansion. Together, these results demonstrate that C. burnetii actively directs PV-autophagosome interactions by using the Dot/Icm T4SS. PMID:24643534

  17. Attenuation of the Type IV Pilus Retraction Motor Influences Neisseria gonorrhoeae Social and Infection Behavior.

    PubMed

    Hockenberry, Alyson M; Hutchens, Danielle M; Agellon, Al; So, Magdalene

    2016-12-06

    Retraction of the type IV pilus (Tfp) mediates DNA uptake, motility, and social and infection behavior in a wide variety of prokaryotes. To date, investigations into Tfp retraction-dependent activities have used a mutant deleted of PilT, the ATPase motor protein that causes the pilus fiber to retract. ΔpilT cells are nontransformable, nonmotile, and cannot aggregate into microcolonies. We tested the hypothesis that these retraction-dependent activities are sensitive to the strength of PilT enzymatic activity by using the pathogen Neisseria gonorrhoeae as a model. We constructed an N. gonorrhoeae mutant with an amino acid substitution in the PilT Walker B box (a substitution of cysteine for leucine at position 201, encoded by pilTL201C). Purified PilTL201C forms a native hexamer, but mutant hexamers hydrolyze ATP at half the maximal rate. N. gonorrhoeae pilTL201C cells produce Tfp fibers, crawl at the same speed as the wild-type (wt) parent, and are equally transformable. However, the social behavior of pilTL201C cells is intermediate between the behaviors of wt and ΔpilT cells. The infection behavior of pilTL201C is also defective, due to its failure to activate the epidermal growth factor receptor (EGFR)-heparin-binding EGF-like growth factor (HB-EGF) pathway. Our study indicates that pilus retraction, per se, is not sufficient for N. gonorrhoeae microcolony formation or infectivity; rather, these activities are sensitive to the strength of PilT enzymatic activity. We discuss the implications of these findings for Neisseria pathogenesis in the context of mechanobiology.

  18. Attenuation of the Type IV Pilus Retraction Motor Influences Neisseria gonorrhoeae Social and Infection Behavior

    PubMed Central

    Hutchens, Danielle M.; Agellon, Al

    2016-01-01

    ABSTRACT Retraction of the type IV pilus (Tfp) mediates DNA uptake, motility, and social and infection behavior in a wide variety of prokaryotes. To date, investigations into Tfp retraction-dependent activities have used a mutant deleted of PilT, the ATPase motor protein that causes the pilus fiber to retract. ΔpilT cells are nontransformable, nonmotile, and cannot aggregate into microcolonies. We tested the hypothesis that these retraction-dependent activities are sensitive to the strength of PilT enzymatic activity by using the pathogen Neisseria gonorrhoeae as a model. We constructed an N. gonorrhoeae mutant with an amino acid substitution in the PilT Walker B box (a substitution of cysteine for leucine at position 201, encoded by pilTL201C). Purified PilTL201C forms a native hexamer, but mutant hexamers hydrolyze ATP at half the maximal rate. N. gonorrhoeae pilTL201C cells produce Tfp fibers, crawl at the same speed as the wild-type (wt) parent, and are equally transformable. However, the social behavior of pilTL201C cells is intermediate between the behaviors of wt and ΔpilT cells. The infection behavior of pilTL201C is also defective, due to its failure to activate the epidermal growth factor receptor (EGFR)-heparin-binding EGF-like growth factor (HB-EGF) pathway. Our study indicates that pilus retraction, per se, is not sufficient for N. gonorrhoeae microcolony formation or infectivity; rather, these activities are sensitive to the strength of PilT enzymatic activity. We discuss the implications of these findings for Neisseria pathogenesis in the context of mechanobiology. PMID:27923924

  19. [Simultaneous manifestation of thrombocytopenia -induced endoleak type IV and II as late complication following abdominal stentgraft implantation].

    PubMed

    Kurcz, Jacek; Garcarek, Jerzy; Guziński, Maciej; Janczak, Dariusz; Skóra, Jan

    2012-01-01

    Endoleak type IV occurs very rarely and typically was observed 4-8 weeks following implantation of previous generation stentgrafts. Endoleak type II, although relatively common, typically presents early after stentgraft implantation. In our case combined thrombocytopenia-induced endoleaks type II and IV manifested 22 months following stentgraft implantation. The patient presented with abdominal pain and rapid increase in aneurysm diameter. The patient did not require endovascular intervention, medical treatment proved sufficient to relieve clinical symptoms and to prevent progression of the aneurysmal sac. Thrombocytopenia has not manifested itself again so far. The patient is followed-up with increased frequency. It should be noted that occurrence of type IV endoleak, in particular when associated with other type of endoleak, can result from thrombocytopenia. This type of endoleak should be included in differential diagnosis not only in early postinterventional period but also in long-term follow-up, first of all in patients with first generation stentgrafts implanted, featured by porosity of covering material.

  20. Knockdown of DNA ligase IV/XRCC4 by RNA interference inhibits herpes simplex virus type I DNA replication.

    PubMed

    Muylaert, Isabella; Elias, Per

    2007-04-13

    Herpes simplex virus has a linear double-stranded DNA genome with directly repeated terminal sequences needed for cleavage and packaging of replicated DNA. In infected cells, linear genomes rapidly become endless. It is currently a matter of discussion whether the endless genomes are circles supporting rolling circle replication or arise by recombination of linear genomes forming concatemers. Here, we have examined the role of mammalian DNA ligases in the herpes simplex virus, type I (HSV-1) life cycle by employing RNA interference (RNAi) in human 1BR.3.N fibroblasts. We find that RNAi-mediated knockdown of DNA ligase IV and its co-factor XRCC4 causes a hundred-fold reduction of virus yield, a small plaque phenotype, and reduced DNA synthesis. The effect is specific because RNAi against DNA ligase I or DNA ligase III fail to reduce HSV-1 replication. Furthermore, RNAi against DNA ligase IV and XRCC4 does not affect replication of adenovirus. In addition, high multiplicity infections of HSV-1 in human DNA ligase IV-deficient cells reveal a pronounced delay of production of infectious virus. Finally, we demonstrate that formation of endless genomes is inhibited by RNAi-mediated depletion of DNA ligase IV and XRCC4. Our results suggests that DNA ligase IV/XRCC4 serves an important role in the replication cycle of herpes viruses and is likely to be required for the formation of the endless genomes early during productive infection.

  1. Brucella Modulates Secretory Trafficking via Multiple Type IV Secretion Effector Proteins

    PubMed Central

    Myeni, Sebenzile; Child, Robert; Ng, Tony W.; Kupko, John J.; Wehrly, Tara D.; Porcella, Stephen F.; Knodler, Leigh A.; Celli, Jean

    2013-01-01

    The intracellular pathogenic bacterium Brucella generates a replicative vacuole (rBCV) derived from the endoplasmic reticulum via subversion of the host cell secretory pathway. rBCV biogenesis requires the expression of the Type IV secretion system (T4SS) VirB, which is thought to translocate effector proteins that modulate membrane trafficking along the endocytic and secretory pathways. To date, only a few T4SS substrates have been identified, whose molecular functions remain unknown. Here, we used an in silico screen to identify putative T4SS effector candidate proteins using criteria such as limited homology in other bacterial genera, the presence of features similar to known VirB T4SS effectors, GC content and presence of eukaryotic-like motifs. Using β-lactamase and CyaA adenylate cyclase reporter assays, we identified eleven proteins translocated into host cells by Brucella, five in a VirB T4SS-dependent manner, namely BAB1_0678 (BspA), BAB1_0712 (BspB), BAB1_0847 (BspC), BAB1_1671 (BspE) and BAB1_1948 (BspF). A subset of the translocated proteins targeted secretory pathway compartments when ectopically expressed in HeLa cells, and the VirB effectors BspA, BspB and BspF inhibited protein secretion. Brucella infection also impaired host protein secretion in a process requiring BspA, BspB and BspF. Single or combined deletions of bspA, bspB and bspF affected Brucella ability to replicate in macrophages and persist in the liver of infected mice. Taken together, these findings demonstrate that Brucella modulates secretory trafficking via multiple T4SS effector proteins that likely act coordinately to promote Brucella pathogenesis. PMID:23950720

  2. Diversifying selection and concerted evolution of a type IV secretion system in Bartonella.

    PubMed

    Nystedt, Björn; Frank, A Carolin; Thollesson, Mikael; Andersson, Siv G E

    2008-02-01

    We have studied the evolution of a type IV secretion system (T4SS), in Bartonella, which is thought to have changed function from conjugation to erythrocyte adherence following a recent horizontal gene transfer event. The system, called Trw, is unique among T4SSs in that genes encoding both exo- and intracellular components are located within the same duplicated fragment. This provides an opportunity to study the influence of selection on proteins involved in host-pathogen interactions. We sequenced the trw locus from several strains of Bartonella henselae and investigated its evolutionary history by comparisons to other Bartonella species. Several instances of recombination and gene conversion events where detected in the 2- to 5-fold duplicated gene fragments encompassing trwJIH, explaining the homogenization of the anchoring protein TrwI and the divergence of the minor pilus protein TrwJ. A phylogenetic analysis of the 7- to 8-fold duplicated gene coding for the major pilus protein TrwL displayed 2 distinct clades, likely representing a subfunctionalization event. The analyses of the B. henselae strains also identified a recent horizontal transfer event of almost the complete trwL region. We suggest that the switch in function of the T4SS was mediated by the duplication of the genes encoding pilus components and their diversification by combinatorial sequence shuffling within and among genomes. We suggest that the pilus proteins have evolved by diversifying selection to match a divergent set of erythrocyte surface structures, consistent with the trench warfare coevolutionary model.

  3. Phylogenomics Reveals a Diverse Rickettsiales Type IV Secretion System▿ † ‡

    PubMed Central

    Gillespie, Joseph J.; Brayton, Kelly A.; Williams, Kelly P.; Quevedo Diaz, Marco A.; Brown, Wendy C.; Azad, Abdu F.; Sobral, Bruno W.

    2010-01-01

    With an obligate intracellular lifestyle, Alphaproteobacteria of the order Rickettsiales have inextricably coevolved with their various eukaryotic hosts, resulting in small, reductive genomes and strict dependency on host resources. Unsurprisingly, large portions of Rickettsiales genomes encode proteins involved in transport and secretion. One particular transporter that has garnered recent attention from researchers is the type IV secretion system (T4SS). Homologous to the well-studied archetypal vir T4SS of Agrobacterium tumefaciens, the Rickettsiales vir homolog (rvh) T4SS is characterized primarily by duplication of several of its genes and scattered genomic distribution of all components in several conserved islets. Phylogeny estimation suggests a single event of ancestral acquirement of the rvh T4SS, likely from a nonalphaproteobacterial origin. Bioinformatics analysis of over 30 Rickettsiales genome sequences illustrates a conserved core rvh scaffold (lacking only a virB5 homolog), with lineage-specific diversification of several components (rvhB1, rvhB2, and rvhB9b), likely a result of modifications to cell envelope structure. This coevolution of the rvh T4SS and cell envelope morphology is probably driven by adaptations to various host cells, identifying the transporter as an important target for vaccine development. Despite the genetic intractability of Rickettsiales, recent advancements have been made in the characterization of several components of the rvh T4SS, as well as its putative regulators and substrates. While current data favor a role in effector translocation, functions in DNA uptake and release and/or conjugation cannot at present be ruled out, especially considering that a mechanism for plasmid transfer in Rickettsia spp. has yet to be proposed. PMID:20176788

  4. Apolipoprotein(a) Kringle-IV Type 2 Copy Number Variation Is Associated with Venous Thromboembolism

    PubMed Central

    Sticchi, Elena; Magi, Alberto; Kamstrup, Pia R.; Marcucci, Rossella; Prisco, Domenico; Martinelli, Ida; Mannucci, Pier Mannuccio; Abbate, Rosanna; Giusti, Betti

    2016-01-01

    In addition to the established association between high lipoprotein(a) [Lp(a)] concentrations and coronary artery disease, an association between Lp(a) and venous thromboembolism (VTE) has also been described. Lp(a) is controlled by genetic variants in LPA gene, coding for apolipoprotein(a), including the kringle-IV type 2 (KIV-2) size polymorphism. Aim of the study was to investigate the role of LPA gene KIV-2 size polymorphism and single nucleotide polymorphisms (SNPs) (rs1853021, rs1800769, rs3798220, rs10455872) in modulating VTE susceptibility. Five hundred and sixteen patients with VTE without hereditary and acquired thrombophilia and 1117 healthy control subjects, comparable for age and sex, were investigated. LPA KIV-2 polymorphism, rs3798220 and rs10455872 SNPs were genotyped by TaqMan technology. Concerning rs1853021 and rs1800769 SNPs, PCR-RFLP assay was used. LPA KIV-2 repeat number was significantly lower in patients than in controls [median (interquartile range) 11(6–17) vs 15(9–25), p<0.0001]. A significantly higher prevalence of KIV-2 repeat number ≤7 was observed in patients than in controls (33.5% vs 15.5%, p<0.0001). KIV-2 repeat number was independently associated with VTE (p = 4.36 x10-9), as evidenced by the general linear model analysis adjusted for transient risk factors. No significant difference in allele frequency for all SNPs investigated was observed. Haplotype analysis showed that LPA haplotypes rather than individual SNPs influenced disease susceptibility. Receiver operating characteristic curves analysis showed that a combined risk prediction model, including KIV-2 size polymorphism and clinical variables, had a higher performance in identifying subjects at VTE risk than a clinical-only model, also separately in men and women. PMID:26900838

  5. Apolipoprotein(a) Kringle-IV Type 2 Copy Number Variation Is Associated with Venous Thromboembolism.

    PubMed

    Sticchi, Elena; Magi, Alberto; Kamstrup, Pia R; Marcucci, Rossella; Prisco, Domenico; Martinelli, Ida; Mannucci, Pier Mannuccio; Abbate, Rosanna; Giusti, Betti

    2016-01-01

    In addition to the established association between high lipoprotein(a) [Lp(a)] concentrations and coronary artery disease, an association between Lp(a) and venous thromboembolism (VTE) has also been described. Lp(a) is controlled by genetic variants in LPA gene, coding for apolipoprotein(a), including the kringle-IV type 2 (KIV-2) size polymorphism. Aim of the study was to investigate the role of LPA gene KIV-2 size polymorphism and single nucleotide polymorphisms (SNPs) (rs1853021, rs1800769, rs3798220, rs10455872) in modulating VTE susceptibility. Five hundred and sixteen patients with VTE without hereditary and acquired thrombophilia and 1117 healthy control subjects, comparable for age and sex, were investigated. LPA KIV-2 polymorphism, rs3798220 and rs10455872 SNPs were genotyped by TaqMan technology. Concerning rs1853021 and rs1800769 SNPs, PCR-RFLP assay was used. LPA KIV-2 repeat number was significantly lower in patients than in controls [median (interquartile range) 11(6-17) vs 15(9-25), p<0.0001]. A significantly higher prevalence of KIV-2 repeat number ≤7 was observed in patients than in controls (33.5% vs 15.5%, p<0.0001). KIV-2 repeat number was independently associated with VTE (p = 4.36 x10-9), as evidenced by the general linear model analysis adjusted for transient risk factors. No significant difference in allele frequency for all SNPs investigated was observed. Haplotype analysis showed that LPA haplotypes rather than individual SNPs influenced disease susceptibility. Receiver operating characteristic curves analysis showed that a combined risk prediction model, including KIV-2 size polymorphism and clinical variables, had a higher performance in identifying subjects at VTE risk than a clinical-only model, also separately in men and women.

  6. Peptidomimetic Small Molecules Disrupt Type IV Secretion System Activity in Diverse Bacterial Pathogens

    PubMed Central

    Shaffer, Carrie L.; Good, James A. D.; Kumar, Santosh; Krishnan, K. Syam; Gaddy, Jennifer A.; Loh, John T.; Chappell, Joseph; Almqvist, Fredrik

    2016-01-01

    ABSTRACT Bacteria utilize complex type IV secretion systems (T4SSs) to translocate diverse effector proteins or DNA into target cells. Despite the importance of T4SSs in bacterial pathogenesis, the mechanism by which these translocation machineries deliver cargo across the bacterial envelope remains poorly understood, and very few studies have investigated the use of synthetic molecules to disrupt T4SS-mediated transport. Here, we describe two synthetic small molecules (C10 and KSK85) that disrupt T4SS-dependent processes in multiple bacterial pathogens. Helicobacter pylori exploits a pilus appendage associated with the cag T4SS to inject an oncogenic effector protein (CagA) and peptidoglycan into gastric epithelial cells. In H. pylori, KSK85 impedes biogenesis of the pilus appendage associated with the cag T4SS, while C10 disrupts cag T4SS activity without perturbing pilus assembly. In addition to the effects in H. pylori, we demonstrate that these compounds disrupt interbacterial DNA transfer by conjugative T4SSs in Escherichia coli and impede vir T4SS-mediated DNA delivery by Agrobacterium tumefaciens in a plant model of infection. Of note, C10 effectively disarmed dissemination of a derepressed IncF plasmid into a recipient bacterial population, thus demonstrating the potential of these compounds in mitigating the spread of antibiotic resistance determinants driven by conjugation. To our knowledge, this study is the first report of synthetic small molecules that impair delivery of both effector protein and DNA cargos by diverse T4SSs. PMID:27118587

  7. Type IV pili interactions promote intercellular association and moderate swarming of Pseudomonas aeruginosa

    PubMed Central

    Anyan, Morgen E.; Amiri, Aboutaleb; Harvey, Cameron W.; Tierra, Giordano; Morales-Soto, Nydia; Driscoll, Callan M.; Alber, Mark S.; Shrout, Joshua D.

    2014-01-01

    Pseudomonas aeruginosa is a ubiquitous bacterium that survives in many environments, including as an acute and chronic pathogen in humans. Substantial evidence shows that P. aeruginosa behavior is affected by its motility, and appendages known as flagella and type IV pili (TFP) are known to confer such motility. The role these appendages play when not facilitating motility or attachment, however, is unclear. Here we discern a passive intercellular role of TFP during flagellar-mediated swarming of P. aeruginosa that does not require TFP extension or retraction. We studied swarming at the cellular level using a combination of laboratory experiments and computational simulations to explain the resultant patterns of cells imaged from in vitro swarms. Namely, we used a computational model to simulate swarming and to probe for individual cell behavior that cannot currently be otherwise measured. Our simulations showed that TFP of swarming P. aeruginosa should be distributed all over the cell and that TFP−TFP interactions between cells should be a dominant mechanism that promotes cell−cell interaction, limits lone cell movement, and slows swarm expansion. This predicted physical mechanism involving TFP was confirmed in vitro using pairwise mixtures of strains with and without TFP where cells without TFP separate from cells with TFP. While TFP slow swarm expansion, we show in vitro that TFP help alter collective motion to avoid toxic compounds such as the antibiotic carbenicillin. Thus, TFP physically affect P. aeruginosa swarming by actively promoting cell−cell association and directional collective motion within motile groups to aid their survival. PMID:25468980

  8. Campylobacter fetus Subspecies Contain Conserved Type IV Secretion Systems on Multiple Genomic Islands and Plasmids

    PubMed Central

    van der Graaf–van Bloois, Linda; Miller, William G.; Yee, Emma; Gorkiewicz, Gregor; Forbes, Ken J.; Zomer, Aldert L.; Wagenaar, Jaap A.; Duim, Birgitta

    2016-01-01

    The features contributing to differences in pathogenicity of the Campylobacter fetus subspecies are unknown. Putative factors involved in pathogenesis are located in genomic islands that encode a type IV secretion system (T4SS) and fic domain (filamentation induced by cyclic AMP) proteins, which may disrupt host cell processes. In the genomes of 27 C. fetus strains, three phylogenetically-different T4SS-encoding regions (T4SSs) were identified: one was located in both the chromosome and in extra-chromosomal plasmids; one was located exclusively in the chromosome; and one exclusively in extra-chromosomal plasmids. We observed that C. fetus strains can contain multiple T4SSs and that homologous T4SSs can be present both in chromosomal genomic islands (GI) and on plasmids in the C. fetus strains. The GIs of the chromosomally located T4SS differed mainly by the presence of fic genes, insertion sequence elements and phage-related or hypothetical proteins. Comparative analysis showed that T4SS sequences, inserted in the same locations, were conserved in the studied C. fetus genomes. Using phylogenetic analysis of the T4SSs, it was shown that C. fetus may have acquired the T4SS regions from other Campylobacter species by horizontal gene transfer. The identified T4SSs and fic genes were found in Cff and Cfv strains, although the presence of T4SSs and fic genes were significantly associated with Cfv strains. The T4SSs and fic genes could not be associated with S-layer serotypes or geographical origin of the strains. PMID:27049518

  9. Archaeal flagellin combines a bacterial type IV pilin domain with an Ig-like domain

    PubMed Central

    Braun, Tatjana; Vos, Matthijn R.; Kalisman, Nir; Sherman, Nicholas E.; Rachel, Reinhard; Wirth, Reinhard; Schröder, Gunnar F.; Egelman, Edward H.

    2016-01-01

    The bacterial flagellar apparatus, which involves ∼40 different proteins, has been a model system for understanding motility and chemotaxis. The bacterial flagellar filament, largely composed of a single protein, flagellin, has been a model for understanding protein assembly. This system has no homology to the eukaryotic flagellum, in which the filament alone, composed of a microtubule-based axoneme, contains more than 400 different proteins. The archaeal flagellar system is simpler still, in some cases having ∼13 different proteins with a single flagellar filament protein. The archaeal flagellar system has no homology to the bacterial one and must have arisen by convergent evolution. However, it has been understood that the N-terminal domain of the archaeal flagellin is a homolog of the N-terminal domain of bacterial type IV pilin, showing once again how proteins can be repurposed in evolution for different functions. Using cryo-EM, we have been able to generate a nearly complete atomic model for a flagellar-like filament of the archaeon Ignicoccus hospitalis from a reconstruction at ∼4-Å resolution. We can now show that the archaeal flagellar filament contains a β-sandwich, previously seen in the FlaF protein that forms the anchor for the archaeal flagellar filament. In contrast to the bacterial flagellar filament, where the outer globular domains make no contact with each other and are not necessary for either assembly or motility, the archaeal flagellin outer domains make extensive contacts with each other that largely determine the interesting mechanical properties of these filaments, allowing these filaments to flex. PMID:27578865

  10. A type IV translocated Legionella cysteine phytase counteracts intracellular growth restriction by phytate.

    PubMed

    Weber, Stephen; Stirnimann, Christian U; Wieser, Mara; Frey, Daniel; Meier, Roger; Engelhardt, Sabrina; Li, Xiaodan; Capitani, Guido; Kammerer, Richard A; Hilbi, Hubert

    2014-12-05

    The causative agent of Legionnaires' pneumonia, Legionella pneumophila, colonizes diverse environmental niches, including biofilms, plant material, and protozoa. In these habitats, myo-inositol hexakisphosphate (phytate) is prevalent and used as a phosphate storage compound or as a siderophore. L. pneumophila replicates in protozoa and mammalian phagocytes within a unique "Legionella-containing vacuole." The bacteria govern host cell interactions through the Icm/Dot type IV secretion system (T4SS) and ∼300 different "effector" proteins. Here we characterize a hitherto unrecognized Icm/Dot substrate, LppA, as a phytate phosphatase (phytase). Phytase activity of recombinant LppA required catalytically essential cysteine (Cys(231)) and arginine (Arg(237)) residues. The structure of LppA at 1.4 Å resolution revealed a mainly α-helical globular protein stabilized by four antiparallel β-sheets that binds two phosphate moieties. The phosphates localize to a P-loop active site characteristic of dual specificity phosphatases or to a non-catalytic site, respectively. Phytate reversibly abolished growth of L. pneumophila in broth, and growth inhibition was relieved by overproduction of LppA or by metal ion titration. L. pneumophila lacking lppA replicated less efficiently in phytate-loaded Acanthamoeba castellanii or Dictyostelium discoideum, and the intracellular growth defect was complemented by the phytase gene. These findings identify the chelator phytate as an intracellular bacteriostatic component of cell-autonomous host immunity and reveal a T4SS-translocated L. pneumophila phytase that counteracts intracellular bacterial growth restriction by phytate. Thus, bacterial phytases might represent therapeutic targets to combat intracellular pathogens.

  11. Functional analysis of an unusual type IV pilus in the Gram‐positive Streptococcus sanguinis

    PubMed Central

    Gurung, Ishwori; Spielman, Ingrid; Davies, Mark R.; Lala, Rajan; Gaustad, Peter; Biais, Nicolas

    2015-01-01

    Summary Type IV pili (Tfp), which have been studied extensively in a few Gram‐negative species, are the paradigm of a group of widespread and functionally versatile nano‐machines. Here, we performed the most detailed molecular characterisation of Tfp in a Gram‐positive bacterium. We demonstrate that the naturally competent S treptococcus sanguinis produces retractable Tfp, which like their Gram‐negative counterparts can generate hundreds of piconewton of tensile force and promote intense surface‐associated motility. Tfp power ‘train‐like’ directional motion parallel to the long axis of chains of cells, leading to spreading zones around bacteria grown on plates. However, S . sanguinis  Tfp are not involved in DNA uptake, which is mediated by a related but distinct nano‐machine, and are unusual because they are composed of two pilins in comparable amounts, rather than one as normally seen. Whole genome sequencing identified a locus encoding all the genes involved in Tfp biology in S . sanguinis. A systematic mutational analysis revealed that Tfp biogenesis in S . sanguinis relies on a more basic machinery (only 10 components) than in Gram‐negative species and that a small subset of four proteins dispensable for pilus biogenesis are essential for motility. Intriguingly, one of the piliated mutants that does not exhibit spreading retains microscopic motility but moves sideways, which suggests that the corresponding protein controls motion directionality. Besides establishing S . sanguinis as a useful new model for studying Tfp biology, these findings have important implications for our understanding of these widespread filamentous nano‐machines. PMID:26435398

  12. Archaeal flagellin combines a bacterial type IV pilin domain with an Ig-like domain.

    PubMed

    Braun, Tatjana; Vos, Matthijn R; Kalisman, Nir; Sherman, Nicholas E; Rachel, Reinhard; Wirth, Reinhard; Schröder, Gunnar F; Egelman, Edward H

    2016-09-13

    The bacterial flagellar apparatus, which involves ∼40 different proteins, has been a model system for understanding motility and chemotaxis. The bacterial flagellar filament, largely composed of a single protein, flagellin, has been a model for understanding protein assembly. This system has no homology to the eukaryotic flagellum, in which the filament alone, composed of a microtubule-based axoneme, contains more than 400 different proteins. The archaeal flagellar system is simpler still, in some cases having ∼13 different proteins with a single flagellar filament protein. The archaeal flagellar system has no homology to the bacterial one and must have arisen by convergent evolution. However, it has been understood that the N-terminal domain of the archaeal flagellin is a homolog of the N-terminal domain of bacterial type IV pilin, showing once again how proteins can be repurposed in evolution for different functions. Using cryo-EM, we have been able to generate a nearly complete atomic model for a flagellar-like filament of the archaeon Ignicoccus hospitalis from a reconstruction at ∼4-Å resolution. We can now show that the archaeal flagellar filament contains a β-sandwich, previously seen in the FlaF protein that forms the anchor for the archaeal flagellar filament. In contrast to the bacterial flagellar filament, where the outer globular domains make no contact with each other and are not necessary for either assembly or motility, the archaeal flagellin outer domains make extensive contacts with each other that largely determine the interesting mechanical properties of these filaments, allowing these filaments to flex.

  13. Type IV fimbrial subunit protein ApfA contributes to protection against porcine pleuropneumonia

    PubMed Central

    2012-01-01

    Porcine pleuropneumonia caused by Actinobacillus pleuropneumoniae accounts for serious economic losses in the pig farming industry worldwide. We examined here the immunogenicity and protective efficacy of the recombinant type IV fimbrial subunit protein ApfA as a single antigen vaccine against pleuropneumonia, or as a component of a multi-antigen preparation comprising five other recombinant antigens derived from key virulence factors of A. pleuropneumoniae (ApxIA, ApxIIA, ApxIIIA, ApxIVA and TbpB). Immunization of pigs with recombinant ApfA alone induced high levels of specific serum antibodies and provided partial protection against challenge with the heterologous A. pleuropneumoniae serotype 9 strain. This protection was higher than that engendered by vaccination with rApxIVA or rTbpB alone and similar to that observed after immunization with the tri-antigen combination of rApxIA, rApxIIA and rApxIIIA. In addition, rApfA improved the vaccination potential of the penta-antigen mixture of rApxIA, rApxIIA, rApxIIIA, rApxIVA and rTbpB proteins, where the hexa-antigen vaccine containing rApfA conferred a high level of protection on pigs against the disease. Moreover, when rApfA was used for vaccination alone or in combination with other antigens, such immunization reduced the number of pigs colonized with the challenge strain. These results indicate that ApfA could be a valuable component of an efficient subunit vaccine for the prevention of porcine pleuropneumonia. PMID:22240397

  14. Modulation of tumor cell stiffness and migration by type IV collagen through direct activation of integrin signaling pathway.

    PubMed

    Chen, Sheng-Yi; Lin, Jo-Shi; Yang, Bei-Chang

    2014-08-01

    Excessive collagen deposition plays a critical role in tumor progression and metastasis. To understand how type IV collagen affects mechanical stiffness and migration, low-collagen-IV-expressing transfectants of B16F10, U118MG, and Huh7 (denoted shCol cells) were established by the lentiviral-mediated delivery of small interfering RNA against type IV-α1 collagen (Col4A1). Although having similar growth rates, shCol cells showed a flatter morphology compared to that of the corresponding controls. Notably, knocking down the Col4A1 gene conferred the cells with higher levels of elasticity and lower motility. Exposure to blocking antibodies against human β1 integrin or α2β1 integrin or the pharmacological inhibition of Src and ERK activity by PP1 and U0126, respectively, effectively reduced cell motility and raised cell stiffness. Reduced Src and ERK activities in shCol cells indicate the involvement of a collagen IV/integrin signaling pathway. The forced expression of β1 integrin significantly stimulated Src and ERK phosphorylation, reduced cell stiffness, and accelerated cell motility. In an experimental metastasis assay using C57BL/6 mice, B16F10 shCol cells formed significantly fewer and smaller lung nodules, confirming the contribution of collagen to metastasis. In summary, the integrin signaling pathway activated in a tumor environment with collagen deposition is responsible for low cell elasticity and high metastatic ability.

  15. Cationic Group-IV pincer-type complexes for polymerization and hydroamination catalysis.

    PubMed

    Luconi, Lapo; Klosin, Jerzy; Smith, Austin J; Germain, Stéphane; Schulz, Emmanuelle; Hannedouche, Jérôme; Giambastiani, Giuliano

    2013-12-07

    Neutral Zr(IV) and Hf(IV) dimethyl complexes stabilized by unsymmetrical dianionic {N,C,N'} pincer ligands have been prepared from their corresponding bis-amido complexes upon treatment with AlMe3. Their structure consists of a central σ-bonded aryl donor group (C) capable of forming robust M-C bonds with the metal center, enforced by the synergic effect of both the coordination of peripheral donor groups (N) and the chelating rigid structure of the {N,C,N} ligand framework. Such a combination translates into systems having a unique balance between stability and reactivity. These Zr(IV) and Hf(IV) dimethyl complexes were converted in situ into cationic species [M(IV){N(-),C(-),N}Me][B(C6F5)4] which are active catalysts for the room temperature (r.t.) intramolecular hydroamination/cyclization of primary and secondary aminoalkenes as well as for the high temperature ethylene-1-octene copolymerizations.

  16. Comparative Genomics of the Zoonotic Pathogen Ehrlichia chaffeensis Reveals Candidate Type IV Effectors and Putative Host Cell Targets

    PubMed Central

    Noroy, Christophe; Meyer, Damien F.

    2017-01-01

    During infection, some intracellular pathogenic bacteria use a dedicated multiprotein complex known as the type IV secretion system to deliver type IV effector (T4E) proteins inside the host cell. These T4Es allow the bacteria to evade host defenses and to subvert host cell processes to their own advantage. Ehrlichia chaffeensis is a tick-transmitted obligate intracellular pathogenic bacterium, which causes human monocytic ehrlichiosis. Using comparative whole genome analysis, we identified the relationship between eight available E. chaffeensis genomes isolated from humans and show that these genomes are highly conserved. We identified the candidate core type IV effectome of E. chaffeensis and some conserved intracellular adaptive strategies. We assigned the West Paces strain to genetic group II and predicted the repertoires of T4Es encoded by E. chaffeensis genomes, as well as some putative host cell targets. We demonstrated that predicted T4Es are preferentially distributed in gene sparse regions of the genome. In addition to the identification of the two known type IV effectors of Anaplasmataceae, we identified two novel candidates T4Es, ECHLIB_RS02720 and ECHLIB_RS04640, which are not present in all E. chaffeensis strains and could explain some variations in inter-strain virulence. We also identified another novel candidate T4E, ECHLIB_RS02720, a hypothetical protein exhibiting EPIYA, and NLS domains as well as a classical type IV secretion signal, suggesting an important role inside the host cell. Overall, our results agree with current knowledge of Ehrlichia molecular pathogenesis, and reveal novel candidate T4Es that require experimental validation. This work demonstrates that comparative effectomics enables identification of important host pathways targeted by the bacterial pathogen. Our study, which focuses on the type IV effector repertoires among several strains of E. chaffeensis species, is an original approach and provides rational putative targets

  17. Structure of an Essential Type IV Pilus Biogenesis Protein Provides Insights into Pilus and Type II Secretion Systems

    PubMed Central

    Yamagata, Atsushi; Milgotina, Ekaterina; Scanlon, Karen; Craig, Lisa; Tainer, John A.; Donnenberg, Michael S.

    2012-01-01

    Type IV pili (T4Ps) are long cell surface filaments, essential for microcolony formation, tissue adherence, motility, transformation, and virulence by human pathogens. The enteropathogenic E. colibundle-forming pilus (BFP) is a prototypic T4P assembled and powered by BfpD, a conserved GspE secretion superfamily ATPase held by inner membrane proteins BfpC andBfpE, a GspF-family membrane protein. Although the T4P assembly machinery shares similarity with type II secretion (T2S) systems, the structural biochemistry of the T4P machine has been obscure. Here, we report the crystal structure of the two-domain BfpC cytoplasmic region (N-BfpC), responsible for binding to ATPase BfpD and membrane protein BfpE. The N-BfpC structure reveals a prominent central cleft between two α/β domains. Despite negligible sequence similarity, N-BfpC resembles PilM, a cytoplasmic T4P biogenesis protein.Yet surprisingly, N-BfpC has far greaterstructural similarity to T2S component EpsL, with which it also shares virtually no sequence identity. The C-terminus of the cytoplasmic domain, which leads to the transmembrane segment not present in the crystal structure, exits N-BfpC at a positively-charged surface that most likely interacts with the inner membrane, positioning its central cleft for interactions with other Bfp components.Point mutations in surface-exposed N-BfpC residues predicted to be critical for interactions among BfpC, BfpE and BfpD disrupt pilus biogenesis without precluding interactions with BfpE and BfpD and without affecting BfpD ATPase activity. These results illuminate the relationships between T4P biogenesis and T2S systems,imply that subtle changes in component residue interactions can have profound effects on function and pathogenesis, and suggest that T4P systems may be disrupted by inhibitors that donot preclude component assembly. PMID:22387466

  18. Are type III-IV muscle afferents required for a normal steady-state exercise hyperpnoea in humans?

    PubMed

    Dempsey, Jerome A; Blain, Grégory M; Amann, Markus

    2014-02-01

    When tested in isolation, stimuli associated with respiratory CO2 exchange, feedforward central command and type III-IV muscle afferent feedback have each been shown to be capable of eliciting exercise-like cardio-ventilatory responses, but their relative contributions in a setting of physiological exercise remains controversial. We reasoned that in order to determine whether any of these regulators are obligatory to the exercise hyperpnoea each needs to be removed or significantly diminished in a setting of physiological steady-state exercise, during which all recognized stimuli (and other potential modulators) are normally operative. In the past few years we and others have used intrathecal fentanyl, a μ-opiate receptor agonist, in humans to reduce the input from type III-IV opiate-sensitive muscle afferents. During various types of intensities and durations of exercise a sustained hypoventilation, as well as reduced systemic pressure and cardioacceleration, were consistently observed with this blockade. These data provide the basis for the hypothesis that type III-IV muscle afferents are obligatory to the hyperpnoea of mild to moderate intensity rhythmic, large muscle, steady-state exercise. We discuss the limitations of these studies, the reasons for their disagreement with previous negative findings, the nature of the muscle afferent feedback stimulus and the need for future investigations.

  19. The determination of PCBs in Rocky Flats Type IV waste sludge by gas chromatography/electron capture detection. Part 2

    SciTech Connect

    Parish, K.J.; Applegate, D.V.; Postlethwait, P.D.; Boparai, A.S.; Reedy, G.T.

    1994-12-01

    Before disposal, radioactive sludge (Type IV) from Rocky Flats Plant (RFP) must be evaluated for polychlorinated biphenyl (PCB) content. The Type IV sludge consists of organic solvents, degreasers, cutting oils, and transuranic (TRU) waste mixed with calcium silicate (MicroCel E{reg_sign} and Oil Dri{reg_sign} to form a grease or paste-like material. For laboratory testing, a nonradioactive simulated Type 17V RFP sludge was prepared at Argonne National Laboratory-East (ANL-E). This sludge has a composition similar to that expected from field samples. In an earlier effort, a simplified method was developed for extraction, cleanup of extract, and determination of PCBs in samples of simulated sludge spiked with Aroclors 1254 and 1260. The simplified method has now been used to determine the presence and quantities of other Aroclors in the simulated sludge, namely, Aroclors 10 1 6, 1221, 1232, 1242, and 1248. The accuracy and precision of the data for these Aroclors were found to be similar to the data for sludges spiked with Aroclors 1254 and 1260. Since actual sludges may vary in composition, the method was also verified by analyzing another source of Type IV simulated sludge, prepared by Argonne National Laboratory-West (ANL-W).

  20. Light regulation of type IV pilus-dependent motility by chemosensor-like elements in Synechocystis PCC6803

    PubMed Central

    Bhaya, Devaki; Takahashi, Akiko; Grossman, Arthur R.

    2001-01-01

    To optimize photosynthesis, cyanobacteria move toward or away from a light source by a process known as phototaxis. Phototactic movement of the cyanobacterium Synechocystis PCC6803 is a surface-dependent phenomenon that requires type IV pili, cellular appendages implicated in twitching and social motility in a range of bacteria. To elucidate regulation of cyanobacterial motility, we generated transposon-tagged mutants with aberrant phototaxis; mutants were either nonmotile or exhibited an “inverted motility response” (negative phototaxis) relative to wild-type cells. Several mutants contained transposons in genes similar to those involved in bacterial chemotaxis. Synechocystis PCC6803 has three loci with chemotaxis-like genes, of which two, Tax1 and Tax3, are involved in phototaxis. Transposons interrupting the Tax1 locus yielded mutants that exhibited an inverted motility response, suggesting that this locus is involved in controlling positive phototaxis. However, a strain null for taxAY1 was nonmotile and hyperpiliated. Interestingly, whereas the C-terminal region of the TaxD1 polypeptide is similar to the signaling domain of enteric methyl-accepting chemoreceptor proteins, the N terminus has two domains resembling chromophore-binding domains of phytochrome, a photoreceptor in plants. Hence, TaxD1 may play a role in perceiving the light stimulus. Mutants in the Tax3 locus are nonmotile and do not make type IV pili. These findings establish links between chemotaxis-like regulatory elements and type IV pilus-mediated phototaxis. PMID:11404477

  1. Cyclic Di-GMP Regulates Type IV Pilus-Dependent Motility in Myxococcus xanthus

    PubMed Central

    Skotnicka, Dorota; Petters, Tobias; Heering, Jan; Hoppert, Michael; Kaever, Volkhard

    2015-01-01

    ABSTRACT The nucleotide-based second messenger bis-(3′-5′)-cyclic dimeric GMP (c-di-GMP) is involved in regulating a plethora of processes in bacteria that are typically associated with lifestyle changes. Myxococcus xanthus undergoes major lifestyle changes in response to nutrient availability, with the formation of spreading colonies in the presence of nutrients and spore-filled fruiting bodies in the absence of nutrients. Here, we investigated the function of c-di-GMP in M. xanthus and show that this bacterium synthesizes c-di-GMP during growth. Manipulation of the c-di-GMP level by expression of either an active, heterologous diguanylate cyclase or an active, heterologous phosphodiesterase correlated with defects in type IV pilus (T4P)-dependent motility, whereas gliding motility was unaffected. An increased level of c-di-GMP correlated with reduced transcription of the pilA gene (which encodes the major pilin of T4P), reduced the assembly of T4P, and altered cell agglutination, whereas a decreased c-di-GMP level correlated with altered cell agglutination. The systematic inactivation of the 24 genes in M. xanthus encoding proteins containing GGDEF, EAL, or HD-GYP domains, which are associated with c-di-GMP synthesis, degradation, or binding, identified three genes encoding proteins important for T4P-dependent motility, whereas all mutants had normal gliding motility. Purified DmxA had diguanylate cyclase activity, whereas the hybrid histidine protein kinases TmoK and SgmT, each of which contains a GGDEF domain, did not have diguanylate cyclase activity. These results demonstrate that c-di-GMP is important for T4P-dependent motility in M. xanthus. IMPORTANCE We provide the first direct evidence that M. xanthus synthesizes c-di-GMP and demonstrate that c-di-GMP is important for T4P-dependent motility, whereas we did not obtain evidence that c-di-GMP regulates gliding motility. The data presented uncovered a novel mechanism for regulation of T4P

  2. Adhesive surface proteins of Erysipelothrix rhusiopathiae bind to polystyrene, fibronectin, and type I and IV collagens.

    PubMed

    Shimoji, Yoshihiro; Ogawa, Yohsuke; Osaki, Makoto; Kabeya, Hidenori; Maruyama, Soichi; Mikami, Takeshi; Sekizaki, Tsutomu

    2003-05-01

    Erysipelothrix rhusiopathiae is a gram-positive bacterium that causes erysipelas in animals and erysipeloid in humans. We found two adhesive surface proteins of E. rhusiopathiae and determined the nucleotide sequences of the genes, which were colocalized and designated rspA and rspB. The two genes were present in all of the serovars of E. rhusiopathiae strains examined. The deduced RspA and RspB proteins contain the C-terminal anchoring motif, LPXTG, which is preceded by repeats of consensus amino acid sequences. The consensus sequences are composed of 78 to 92 amino acids and repeat 16 and 3 times in RspA and RspB, respectively. Adhesive surface proteins of other gram-positive bacteria, including Listeria monocytogenes adhesin-like protein, Streptococcus pyogenes protein F2 and F2-like protein, Streptococcus dysgalactiae FnBB, and Staphylococcus aureus Cna, share the same consensus repeats. Furthermore, the N-terminal regions of RspA and RspB showed characteristics of the collagen-binding domain that was described for Cna. RspA and RspB were expressed in Escherichia coli as histidine-tagged fusion proteins and purified. The recombinant proteins showed a high degree of capacity to bind to polystyrene and inhibited the binding of E. rhusiopathiae onto the abiotic surface in a dose dependent manner. In a solid-phase binding assay, both of the recombinant proteins bound to fibronectin, type I and IV collagens, indicating broad spectrum of their binding ability. It was suggested that both RspA and RspB were exposed on the cell surface of E. rhusiopathiae, as were the bacterial cells agglutinated by the anti-RspA immunoglobulin G (IgG) and anti-RspB IgG. RspA and RspB were present both in surface-antigen extracts and the culture supernatants of E. rhusiopathiae Fujisawa-SmR (serovar 1a) and SE-9 (serovar 2). The recombinant RspA, but not RspB, elicited protection in mice against experimental challenge. These results suggest that RspA and RspB participate in initiation

  3. A distinct and divergent lineage of genomic island-associated Type IV Secretion Systems in Legionella.

    PubMed

    Wee, Bryan A; Woolfit, Megan; Beatson, Scott A; Petty, Nicola K

    2013-01-01

    Legionella encodes multiple classes of Type IV Secretion Systems (T4SSs), including the Dot/Icm protein secretion system that is essential for intracellular multiplication in amoebal and human hosts. Other T4SSs not essential for virulence are thought to facilitate the acquisition of niche-specific adaptation genes including the numerous effector genes that are a hallmark of this genus. Previously, we identified two novel gene clusters in the draft genome of Legionella pneumophila strain 130b that encode homologues of a subtype of T4SS, the genomic island-associated T4SS (GI-T4SS), usually associated with integrative and conjugative elements (ICE). In this study, we performed genomic analyses of 14 homologous GI-T4SS clusters found in eight publicly available Legionella genomes and show that this cluster is unusually well conserved in a region of high plasticity. Phylogenetic analyses show that Legionella GI-T4SSs are substantially divergent from other members of this subtype of T4SS and represent a novel clade of GI-T4SSs only found in this genus. The GI-T4SS was found to be under purifying selection, suggesting it is functional and may play an important role in the evolution and adaptation of Legionella. Like other GI-T4SSs, the Legionella clusters are also associated with ICEs, but lack the typical integration and replication modules of related ICEs. The absence of complete replication and DNA pre-processing modules, together with the presence of Legionella-specific regulatory elements, suggest the Legionella GI-T4SS-associated ICE is unique and may employ novel mechanisms of regulation, maintenance and excision. The Legionella GI-T4SS cluster was found to be associated with several cargo genes, including numerous antibiotic resistance and virulence factors, which may confer a fitness benefit to the organism. The in-silico characterisation of this new T4SS furthers our understanding of the diversity of secretion systems involved in the frequent horizontal gene

  4. Structural Insight into How Bacteria Prevent Interference between Multiple Divergent Type IV Secretion Systems

    PubMed Central

    Phan, Isabelle Q. H.; Scheib, Holger; Subramanian, Sandhya; Edwards, Thomas E.; Lehman, Stephanie S.; Piitulainen, Hanna; Sayeedur Rahman, M.; Rennoll-Bankert, Kristen E.; Staker, Bart L.; Taira, Suvi; Stacy, Robin; Myler, Peter J.; Azad, Abdu F.

    2015-01-01

    ABSTRACT Prokaryotes use type IV secretion systems (T4SSs) to translocate substrates (e.g., nucleoprotein, DNA, and protein) and/or elaborate surface structures (i.e., pili or adhesins). Bacterial genomes may encode multiple T4SSs, e.g., there are three functionally divergent T4SSs in some Bartonella species (vir, vbh, and trw). In a unique case, most rickettsial species encode a T4SS (rvh) enriched with gene duplication. Within single genomes, the evolutionary and functional implications of cross-system interchangeability of analogous T4SS protein components remains poorly understood. To lend insight into cross-system interchangeability, we analyzed the VirB8 family of T4SS channel proteins. Crystal structures of three VirB8 and two TrwG Bartonella proteins revealed highly conserved C-terminal periplasmic domain folds and dimerization interfaces, despite tremendous sequence divergence. This implies remarkable structural constraints for VirB8 components in the assembly of a functional T4SS. VirB8/TrwG heterodimers, determined via bacterial two-hybrid assays and molecular modeling, indicate that differential expression of trw and vir systems is the likely barrier to VirB8-TrwG interchangeability. We also determined the crystal structure of Rickettsia typhi RvhB8-II and modeled its coexpressed divergent paralog RvhB8-I. Remarkably, while RvhB8-I dimerizes and is structurally similar to other VirB8 proteins, the RvhB8-II dimer interface deviates substantially from other VirB8 structures, potentially preventing RvhB8-I/RvhB8-II heterodimerization. For the rvh T4SS, the evolution of divergent VirB8 paralogs implies a functional diversification that is unknown in other T4SSs. Collectively, our data identify two different constraints (spatiotemporal for Bartonella trw and vir T4SSs and structural for rvh T4SSs) that mediate the functionality of multiple divergent T4SSs within a single bacterium. PMID:26646013

  5. Genetic and functional characterization of the type IV secretion system in Wolbachia.

    PubMed

    Rancès, Edwige; Voronin, Denis; Tran-Van, Van; Mavingui, Patrick

    2008-07-01

    A type IV secretion system (T4SS) is used by many symbiotic and pathogenic intracellular bacteria for the successful infection of and survival, proliferation, and persistence within hosts. In this study, the presence and function of the T4SS in Wolbachia strains were investigated by a combination of genetic screening and immunofluorescence microscopy. Two operons of virB-virD4 loci were found in the genome of Wolbachia pipientis strain wAtab3, from the Hymenoptera Asobara tabida, and strain wRi, infecting Drosophila simulans. One operon consisted of five vir genes (virB8, virB9, virB10, virB11, and virD4) and the downstream wspB locus. The other operon was composed of three genes (virB3, virB4, and virB6) and included four additional open reading frames (orf1 to orf4) orientated in the same direction. In cell culture and insect hosts infected with different Wolbachia strains, the bona fide vir genes were polycistronically transcribed, together with the downstream adjacent loci, notably, as virB8 to virD4 and wspB and as virB3, virB4, virB6, and orf1 to orf4. Two peptides encompassing conserved C and N termini of the Wolbachia VirB6 protein were used for the production of polyclonal antibodies. Anti-VirB6 antibodies could detect the corresponding recombinant protein by chemifluorescence on Western blots of total proteins from Escherichia coli transformants and Wolbachia strains cultured in cell lines. Using immunofluorescence microscopy, we further demonstrated that the VirB6 protein was produced by Wolbachia strains in ovaries of insects harboring wAtab3 or wRi and cell lines infected with wAlbB or wMelPop. As VirB6 is known to associate with other VirB proteins to form a membrane-spanning structure, this finding suggests that a T4SS may function in Wolbachia.

  6. Effect of a laboratory surfactant on compatibility of type IV dental stones with addition-cured silicone impression materials.

    PubMed

    Tredwin, Christopher Jeremy; Nesbit, Michael; Butta, Rajeev; Moles, David R

    2008-06-01

    This study compared the effect of a surfactant on surface detail reproduction between combinations of addition-cured silicone impression materials and type IV stones. Six hundred impressions were made of a ruled test block using; Examix-NDS, Doric-Es Flo-Light, Panasil Contact Plus, Extrude Wash and President Plus Jet. Half of the impressions were treated with a surfactant (Aurofilm). Impressions were poured with type IV dental stones; Silky Rock, Fuji Rock, Suprastone and Vel-Mix and the 20 mu line was scored. A laboratory surfactant (Aurofilm) significantly reduced (P<0.01) compatibility with; (i) Examix-NDS and Suprastone, (ii) Examix-NDS and Velmix, (iii) Extrude Wash and Fuji Rock.

  7. Antimicrobial peptide inhibition of fungalysin proteases that target plant type 19 Family IV defense chitinases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cereal crops and other plants produce secreted seed chitinases that reduce pathogenic infection, most likely by targeting the fungal chitinous cell wall. We have shown that corn (Zea mays) produces three GH family 19, plant class IV chitinases, that help in protecting the plant against Fusarium and ...

  8. Development and Application of Laser-Induced Energy Deposition for Flow Control of Edney Type IV Interactions

    DTIC Science & Technology

    2014-10-31

    Relevance of Proposed Research The significance of Edney Type IV interactions, or shockwave interference heating as it was first labelled was seen in a...shock. Their investigation posits that the aerophysical understanding of the effects of shockwave impingement on heat transfer is well known for...separation. They found that the areas of intense heat- ing (measured to ±0.2 mm) corresponded to the point where the generated shockwave impinged upon the

  9. Type IV Collagen Controls the Axogenesis of Cerebellar Granule Cells by Regulating Basement Membrane Integrity in Zebrafish.

    PubMed

    Takeuchi, Miki; Yamaguchi, Shingo; Yonemura, Shigenobu; Kakiguchi, Kisa; Sato, Yoshikatsu; Higashiyama, Tetsuya; Shimizu, Takashi; Hibi, Masahiko

    2015-10-01

    Granule cells (GCs) are the major glutamatergic neurons in the cerebellum, and GC axon formation is an initial step in establishing functional cerebellar circuits. In the zebrafish cerebellum, GCs can be classified into rostromedial and caudolateral groups, according to the locations of their somata in the corresponding cerebellar lobes. The axons of the GCs in the caudolateral lobes terminate on crest cells in the dorsal hindbrain, as well as forming en passant synapses with Purkinje cells in the cerebellum. In the zebrafish mutant shiomaneki, the caudolateral GCs extend aberrant axons. Positional cloning revealed that the shiomaneki (sio) gene locus encodes Col4a6, a subunit of type IV collagen, which, in a complex with Col4a5, is a basement membrane (BM) component. Both col4a5 and col4a6 mutants displayed similar abnormalities in the axogenesis of GCs and retinal ganglion cells (RGCs). Although type IV collagen is reported to control axon targeting by regulating the concentration gradient of an axonal guidance molecule Slit, Slit overexpression did not affect the GC axons. The structure of the BM surrounding the tectum and dorsal hindbrain was disorganized in the col4a5 and col4a6 mutants. Moreover, the abnormal axogenesis of the caudolateral GCs and the RGCs was coupled with aberrant BM structures in the type IV collagen mutants. The regrowth of GC axons after experimental ablation revealed that the original and newly formed axons displayed similar branching and extension abnormalities in the col4a6 mutants. These results collectively suggest that type IV collagen controls GC axon formation by regulating the integrity of the BM, which provides axons with the correct path to their targets.

  10. Type IV Collagen Controls the Axogenesis of Cerebellar Granule Cells by Regulating Basement Membrane Integrity in Zebrafish

    PubMed Central

    Takeuchi, Miki; Yamaguchi, Shingo; Yonemura, Shigenobu; Kakiguchi, Kisa; Sato, Yoshikatsu; Higashiyama, Tetsuya; Shimizu, Takashi; Hibi, Masahiko

    2015-01-01

    Granule cells (GCs) are the major glutamatergic neurons in the cerebellum, and GC axon formation is an initial step in establishing functional cerebellar circuits. In the zebrafish cerebellum, GCs can be classified into rostromedial and caudolateral groups, according to the locations of their somata in the corresponding cerebellar lobes. The axons of the GCs in the caudolateral lobes terminate on crest cells in the dorsal hindbrain, as well as forming en passant synapses with Purkinje cells in the cerebellum. In the zebrafish mutant shiomaneki, the caudolateral GCs extend aberrant axons. Positional cloning revealed that the shiomaneki (sio) gene locus encodes Col4a6, a subunit of type IV collagen, which, in a complex with Col4a5, is a basement membrane (BM) component. Both col4a5 and col4a6 mutants displayed similar abnormalities in the axogenesis of GCs and retinal ganglion cells (RGCs). Although type IV collagen is reported to control axon targeting by regulating the concentration gradient of an axonal guidance molecule Slit, Slit overexpression did not affect the GC axons. The structure of the BM surrounding the tectum and dorsal hindbrain was disorganized in the col4a5 and col4a6 mutants. Moreover, the abnormal axogenesis of the caudolateral GCs and the RGCs was coupled with aberrant BM structures in the type IV collagen mutants. The regrowth of GC axons after experimental ablation revealed that the original and newly formed axons displayed similar branching and extension abnormalities in the col4a6 mutants. These results collectively suggest that type IV collagen controls GC axon formation by regulating the integrity of the BM, which provides axons with the correct path to their targets. PMID:26451951

  11. Fatal Peritoneal Bleeding Following Embolization of a Carotid-Cavernous Fistula in Ehlers-Danlos Syndrome Type IV

    SciTech Connect

    Usinskiene, Jurgita; Mazighi, Mikael; Bisdorff, Annouk; Houdart, Emmanuel

    2006-12-15

    We report the case of a 25-year-old woman treated for a spontaneous carotid-cavernous fistula in a context of Ehlers-Danlos syndrome type IV. Embolization with a transvenous approach was achieved without complications; however, the patient died 72 hr later of massive intraperitoneal bleeding. At autopsy, no lesion of the digestive arteries was identified. Possible causes of this bleeding are discussed.

  12. Mechanism of microstructural deterioration preceding type IV failure in weldment of Mod.9Cr-1Mo steel

    NASA Astrophysics Data System (ADS)

    Lee, J. S.; Maruyama, K.

    2015-07-01

    The objective of the present study was to elucidate the cavity formation mechanism of Type IV failure in weldment of advanced high-Cr ferritic steels. A welded joint of Mod.9Cr-1Mo steel was creep tested at 650 °C under 83 MPa. The creep fracture mode was Type IV failure in the heat affect zone (HAZ). Microstructural characterization of the HAZ and the fracture location, were performed before and after the creep test. The Type IV cracking started in the inter-critical HAZ at a location having fine grain size and coarse M23C6 precipitates. Moreover, the grain structure of the inter-critical HAZ, which is a mixture of soft α and hard α' grains, plays an important role in the stage of cavity evolution into a crack along the grain boundary. This is due to the heterogeneity of local strain between the two kinds of grains. By a synergistic effect of the strain concentration, the coarse precipitates and heterogeneous strain distribution among grains in the inter critical HAZ, facilitates the nucleation and growth of creep cavities, resulting in premature failure of welded joints.

  13. Expression of ABH blood group antigens, Ulex europaeus agglutinin I, and type IV collagen in the sinusoids of hepatocellular carcinoma.

    PubMed

    Terada, T; Nakanuma, Y

    1991-01-01

    The expression of blood group antigens (A, B, H, Lewis(a) and Lewis(b)), Ulex europaeus agglutinin I (UEA-I), factor VIII-related antigen, and type IV collagen on the sinusoids was examined immunohistochemically in 15 cases of hepatocellular carcinomas (HCC), 11 cases of cirrhosis, 12 cases of chronic active hepatitis, and in a control sample of 16 normal livers. Sinusoidal endothelial cells of HCC characteristically showed a diffuse and strong immunoreactivity to ABH blood group antigens in the specimen with a comparable ABO blood group. The sinusoidal endothelial cells were also diffusely and strongly positive for UEA-I receptors. In contrast, in cirrhosis and chronic active hepatitis a few sinusoidal endothelial cells were positive for ABH blood group antigens and UEA-I receptors. In normal livers, only a few sinusoidal endothelial cells were positive for ABH blood group antigens and UEA-1 receptors. Tests for factor VIII-related antigen and Lewis blood group antigens were almost negative on sinusoidal endothelial cells. Although type IV collagen was distributed diffusely in the space of Disse in these four groups, its expression was strongest in HCC. Blood vessels of portal tracts and fibrous septa were positive for ABH blood group antigens, UEA-1 receptors, factor VIII-related antigen, and type IV collagen, but negative for Lewis blood group antigens. These findings suggest that some sinusoidal endothelial cells undergo "capillarization" in cirrhosis and chronic active hepatitis, and that the majority of sinusoidal endothelial cells of HCC have phenotypic characteristics of capillaries.

  14. Multiple strokes and bilateral carotid dissections: a fulminant case of newly diagnosed Ehlers-Danlos syndrome type IV.

    PubMed

    Dohle, C; Baehring, J M

    2012-07-15

    Ehlers-Danlos Syndrome is a rare group of inheritable disorders resulting in abnormal collagen production, leading to skin fragility, joint hypermobility and easy bruising. Six major subtypes have been identified, of which Type IV most often leads to neurovascular complications, may lead to inner organ rupture and overall has the worst prognosis. Early recognition followed by genetic testing is key, since this diagnosis will guide decision making in the management of complications, influence the choice of antiplatelet medications versus anticoagulants and allow for potentially affected family members to be identified, undergo genetic testing and reproductive counseling. We here report the case of a 50 year old woman with a fulminant presentation of Ehlers Danlos Syndrome Type IV, including bilateral carotid and vertebral artery dissection, multiple strokes and liver rupture. Of note, this patient did not have a known history or obvious clinical features of connective tissue disease. Genetic testing confirmed the diagnosis. Review of her family history revealed multiple family members with a history of aortic dissection or aneurysm rupture. This case illustrates that Ehlers Danlos Syndrome Type IV is an important differential diagnosis even in adult patients without a known history of connective tissue disease and no prior complications.

  15. Genomic and Gene-Expression Comparisons among Phage-Resistant Type-IV Pilus Mutants of Pseudomonas syringae pathovar phaseolicola

    PubMed Central

    Sistrom, Mark; Park, Derek; O’Brien, Heath E.; Wang, Zheng; Guttman, David S.; Townsend, Jeffrey P.; Turner, Paul E.

    2015-01-01

    Pseudomonas syringae pv. phaseolicola (Pph) is a significant bacterial pathogen of agricultural crops, and phage Φ6 and other members of the dsRNA virus family Cystoviridae undergo lytic (virulent) infection of Pph, using the type IV pilus as the initial site of cellular attachment. Despite the popularity of Pph/phage Φ6 as a model system in evolutionary biology, Pph resistance to phage Φ6 remains poorly characterized. To investigate differences between phage Φ6 resistant Pph strains, we examined genomic and gene expression variation among three bacterial genotypes that differ in the number of type IV pili expressed per cell: ordinary (wild-type), non-piliated, and super-piliated. Genome sequencing of non-piliated and super-piliated Pph identified few mutations that separate these genotypes from wild type Pph–and none present in genes known to be directly involved in type IV pilus expression. Expression analysis revealed that 81.1% of gene ontology (GO) terms up-regulated in the non-piliated strain were down-regulated in the super-piliated strain. This differential expression is particularly prevalent in genes associated with respiration—specifically genes in the tricarboxylic acid cycle (TCA) cycle, aerobic respiration, and acetyl-CoA metabolism. The expression patterns of the TCA pathway appear to be generally up and down-regulated, in non-piliated and super-piliated Pph respectively. As pilus retraction is mediated by an ATP motor, loss of retraction ability might lead to a lower energy draw on the bacterial cell, leading to a different energy balance than wild type. The lower metabolic rate of the super-piliated strain is potentially a result of its loss of ability to retract. PMID:26670219

  16. A novel arctigenin-containing latex glove prevents latex allergy by inhibiting type I/IV allergic reactions.

    PubMed

    Wang, Yong-Xin; Xue, Dan-Ting; Liu, Meng; Zhou, Zheng-Min; Shang, Jing

    2016-03-01

    The present study aimed at developing a natural compound with anti-allergic effect and stability under latex glove manufacturing conditions and investigating whether its anti-allergic effect is maintained after its addition into the latex. The effects of nine natural compounds on growth of the RBL-2H3 cells and mouse primary spleen lymphocytes were determined using MTT assay. The compounds included glycyrrhizin, osthole, tetrandrine, tea polyphenol, catechin, arctigenin, oleanolic acid, baicalin and oxymatrine. An ELISA assay was used for the in vitro anti-type I/IV allergy screening; in this process β-hexosaminidase, histamine, and IL-4 released from RBL-2H3 cell lines and IFN-γ and IL-2 released from mouse primary spleen lymphocytes were taken as screening indices. The physical stability of eight natural compounds and the dissolubility of arctigenin, selected based on the in vitro pharnacodynamaic screening and the stability evaluation, were detected by HPLC. The in vivo pharmacodynamic confirmation of arctigenin and final latex product was evaluated with a passive cutaneous anaphylaxis (PCA) model and an allergen-specific skin response model. Nine natural compounds showed minor growth inhibition on RBL-2H3 cells and mouse primary spleen lymphocytes. Baicalin and arctigenin had the best anti-type I and IV allergic effects among the natural compounds based on the in vitro pharmacodynamic screening. Arctigenin and catechin had the best physical stability under different manufacturing conditions. Arctigenin was the selected for further evaluation and proven to have anti-type I and IV allergic effects in vivo in a dose-dependent manner. The final product of the arctigenin-containing latex glove had anti-type I and IV allergic effects in vivo which were mainly attributed to arctigenin as proved from the dissolubility results. Arctigenin showed anti-type I and IV allergic effects in vitro and in vivo, with a good stability under latex glove manufacturing conditions

  17. T346Hunter: a novel web-based tool for the prediction of type III, type IV and type VI secretion systems in bacterial genomes.

    PubMed

    Martínez-García, Pedro Manuel; Ramos, Cayo; Rodríguez-Palenzuela, Pablo

    2015-01-01

    T346Hunter (Type Three, Four and Six secretion system Hunter) is a web-based tool for the identification and localisation of type III, type IV and type VI secretion systems (T3SS, T4SS and T6SS, respectively) clusters in bacterial genomes. Non-flagellar T3SS (NF-T3SS) and T6SS are complex molecular machines that deliver effector proteins from bacterial cells into the environment or into other eukaryotic or prokaryotic cells, with significant implications for pathogenesis of the strains encoding them. Meanwhile, T4SS is a more functionally diverse system, which is involved in not only effector translocation but also conjugation and DNA uptake/release. Development of control strategies against bacterial-mediated diseases requires genomic identification of the virulence arsenal of pathogenic bacteria, with T3SS, T4SS and T6SS being major determinants in this regard. Therefore, computational methods for systematic identification of these specialised machines are of particular interest. With the aim of facilitating this task, T346Hunter provides a user-friendly web-based tool for the prediction of T3SS, T4SS and T6SS clusters in newly sequenced bacterial genomes. After inspection of the available scientific literature, we constructed a database of hidden Markov model (HMM) protein profiles and sequences representing the various components of T3SS, T4SS and T6SS. T346Hunter performs searches of such a database against user-supplied bacterial sequences and localises enriched regions in any of these three types of secretion systems. Moreover, through the T346Hunter server, users can visualise the predicted clusters obtained for approximately 1700 bacterial chromosomes and plasmids. T346Hunter offers great help to researchers in advancing their understanding of the biological mechanisms in which these sophisticated molecular machines are involved. T346Hunter is freely available at http://bacterial-virulence-factors.cbgp.upm.es/T346Hunter.

  18. Spontaneous common iliac arteries rupture in Ehlers-Danlos syndrome type IV: report of two cases and review of the literature.

    PubMed Central

    Habib, K.; Memon, M. A.; Reid, D. A.; Fairbrother, B. J.

    2001-01-01

    Two patients with previously undiagnosed Ehlers-Danlos syndrome type IV (EDS IV) presented acutely with clinical features suggestive of hypovolemic shock. Emergency laparotomies in both of them revealed spontaneous rupture of the common iliac arteries. The clinical features, operative findings, surgical approach, outcome and implications are discussed. Images Figure 1 Figure 2 Figure 3 PMID:11320937

  19. Bone mineral density in MPS IV A (Morquio syndrome type A)

    PubMed Central

    Kecskemethy, Heidi H.; Kubaski, Francyne; Harcke, H.T.; Tomatsu, Shunji

    2015-01-01

    Mucopolysaccharidosis IV A (MPS IV A), Morquio A, is caused by deficiency in lysosomal enzyme N-acetylgalactosamine-6-sulfate sulfatase (GALNS), which is responsible for the catabolism of the glycosaminoglycans (GAGs) keratan sulfate (KS) and chondroitin 6-sulfate (C6S). Accumulation of GAGs results in disrupted cartilage formation and skeletal dysplasia. In this prospective cross-sectional study, bone mineral density (BMD) of the whole body (WB), lumbar spine (LS), and lateral distal femur (LDF) was acquired by dual-energy X-ray absorptiometry (DXA) on patients with MPS IV A. Functional abilities, medical history, Tanner score, and laboratory results were reviewed. Age and sex-matched norms were used to calculate Z-scores. Participants included 18 patients (13 females; 16 were unrelated) with a mean age of 21.4 years (3.3 to 40.8 years). While every patient was able to bear weight, 9 were full-time ambulators. Whole-body DXA could be obtained on only 6 patients (5 full-time ambulators) because of respiratory compromise caused by the position, presence of hardware, or positioning difficulties. Mean WB Z-score was −2.0 (range − 0.3 to −4.1). Technical issues invalidating LS DXA in 8 patients included kyphosis at the thoracolumbar junction resulting in overlap of vertebrae in the posterior-anterior view. Mean LS BMD Z-score in full-time ambulators was −3.4 (range − 1.6 to −5.0) and in the non-/partial ambulator was −4.0 (−3.7 to −4.2). Lateral distal femur BMD was acquired on every patient, and average Z-scores were −2 or less at all sites; full-time ambulators exhibited higher BMD. In conclusion, the LDF proved to be the most feasible site to measure in patients with MPS IV A. The higher LDF values in ambulators suggest this should be a consideration in promoting bone health for this group. PMID:26670863

  20. Prevalence of type I allergy to natural rubber latex and type IV allergy to latex and rubber additives in operating room staff with glove-related symptoms.

    PubMed

    Miri, Sara; Pourpak, Zahra; Zarinara, Alireza; Zarinara, Alam; Heidarzade, Marzieh; Kazemnejad, Anoushirvan; Kardar, Gholamali; Firooz, Alireza; Moin, Athar

    2007-01-01

    There is lack of data on the prevalence of latex allergy in the health care setting in Iran. This study was performed to determine the prevalence of type I latex allergy and type IV allergy to latex and rubber additives among the operating room staff with glove-related symptoms in 13 general hospitals in Tehran. Skin-prick tests with commercial latex extract, patch tests with latex and 25 rubber additive series, and total and latex-specific IgE detection were performed on the operating room staff who reported latex glove-related symptoms. Five hundred twelve self-administered questionnaires (100%) were completed by all operating room staff and latex glove-related symptoms were reported by 59 (11.5%) employees. Among all symptomatic operating room staff tested, the prevalence of type I latex allergy was 30.5% and the prevalence rates of type IV allergy to latex and rubber additives were 16.7 and 14.6%, respectively. The most positive patch test result with rubber additives was related to tetramethylthiuram monosulfide (38.5%). The risk factors for type I latex allergy were female sex (p = 0.009) and positive patch test with rubber additives (p = 0.012). Subjects who had positive patch test with latex were significantly more likely to have positive patch test with rubber additives (p < 0.0001). Our results showed a high prevalence of type I latex allergy and type IV allergy to latex and rubber additives. Based on this study, we recommend eliminating powdered latex gloves from the operating rooms of the 13 studied general hospitals and support the substitution of powder-free latex gloves.

  1. Early venous manifestation of Ehlers-Danlos syndrome Type IV through a novel mutation in COL3A1.

    PubMed

    Wendorff, Heiko; Pelisek, Jaroslav; Zimmermann, Alexander; Mayer, Karin; Seidel, Heide; Weirich, Gregor; Hausser, Ingrid; Siegel, Corinna; Zernecke, Alma; Eckstein, Hans-Henning

    2013-01-01

    Ehlers-Danlos syndrome (EDS) leads to abnormalities in the synthesis of collagen and complications involving arterial vessels. We describe here a mutation in the intron 14 of the COL3A1 gene leading to EDS Type IV (EDS IV) associated with venous manifestations only. The patient, an 18-year-old male, suffered from truncal varicosity of the long saphenous vein on both sides. Conventional stripping surgery of the left saphenous vein revealed an extremely vulnerable ectatic superficial femoral vein. An inserted vein graft occluded, and venous thrombectomy was unsuccessful. A conservative anticoagulant and compression therapy finally succeeded. This is the first report describing EDS IV due to a mutation in intron 14 of the COL3A1 gene leading to venous manifestations without affecting arterial vessels at clinical presentation. Our findings imply that molecular genetic analysis should be considered in patients with unusual clinical presentation and that conservative therapy should be applied until a suspected clinical diagnosis has been secured.

  2. Role of α1 and α2 chains of type IV collagen in early fibrotic lesions of idiopathic interstitial pneumonias and migration of lung fibroblasts.

    PubMed

    Urushiyama, Hirokazu; Terasaki, Yasuhiro; Nagasaka, Shinya; Terasaki, Mika; Kunugi, Shinobu; Nagase, Takahide; Fukuda, Yuh; Shimizu, Akira

    2015-08-01

    Early fibrotic lesions are thought to be the initial findings of fibrogenesis in idiopathic interstitial pneumonias, but little is known about their properties. Type IV collagen comprises six gene products, α1-α6, and although it is known as a major basement membrane component, its abnormal deposition is seen in fibrotic lesions of certain organs. We studied the expression of type I and III collagen and all α chains of type IV collagen in lung specimens from patients with usual interstitial pneumonia (UIP) or organizing pneumonia (OP) via immunohistochemistry. With cultured lung fibroblasts, we analyzed the expression and function of all α chains of type IV collagen via immunohistochemistry, western blotting, real-time quantitative PCR, and a Boyden chamber migration assay after the knockdown of α1 and α2 chains. Although we observed type I and III collagens in early fibrotic lesions of both UIP and OP, we found type IV collagen, especially α1 and α2 chains, in early fibrotic lesions of UIP but not OP. Fibroblasts enhanced the expression of α1 and α2 chains of type IV collagen after transforming growth factor-β1 stimulation. Small interfering RNA against α1 and α2 chains increased fibroblast migration, with upregulated phosphorylation of focal adhesion kinase (FAK), and adding medium containing fibroblast-produced α1 and α2 chains reduced the increased levels of fibroblast migration and phosphorylation of FAK. Fibroblasts in OP were positive for phosphorylated FAK but fibroblasts in UIP were not. These results suggest that fibroblasts in UIP with type IV collagen deposition, especially α1 and α2 chains, have less ability to migrate from early fibrotic lesions than fibroblasts in OP without type IV collagen deposition. Thus, type IV collagen deposition in early fibrotic lesions of UIP may be implicated in refractory pathophysiology including migration of lesion fibroblasts via a FAK pathway.

  3. De Novo and Inherited Mutations in COL4A2, Encoding the Type IV Collagen α2 Chain Cause Porencephaly

    PubMed Central

    Yoneda, Yuriko; Haginoya, Kazuhiro; Arai, Hiroshi; Yamaoka, Shigeo; Tsurusaki, Yoshinori; Doi, Hiroshi; Miyake, Noriko; Yokochi, Kenji; Osaka, Hitoshi; Kato, Mitsuhiro; Matsumoto, Naomichi; Saitsu, Hirotomo

    2012-01-01

    Porencephaly is a neurological disorder characterized by fluid-filled cysts or cavities in the brain that often cause hemiplegia. It has been suggested that porencephalic cavities result from focal cerebral degeneration involving hemorrhages. De novo or inherited heterozygous mutations in COL4A1, which encodes the type IV α1 collagen chain that is essential for structural integrity for vascular basement membranes, have been reported in individuals with porencephaly. Most mutations occurred at conserved Gly residues in the Gly-Xaa-Yaa repeats of the triple-helical domain, leading to alterations of the α1α1α2 heterotrimers. Here we report on two individuals with porencephaly caused by a heterozygous missense mutation in COL4A2, which encodes the type IV α2 collagen chain. Mutations c.3455G>A and c.3110G>A, one in each of the individuals, cause Gly residues in the Gly-Xaa-Yaa repeat to be substituted as p.Gly1152Asp and p.Gly1037Glu, respectively, probably resulting in alterations of the α1α1α2 heterotrimers. The c.3455G>A mutation was found in the proband's mother, who showed very mild monoparesis of the left upper extremity, and the maternal elder uncle, who had congenital hemiplegia. The maternal grandfather harboring the mutation is asymptomatic. The c.3110G>A mutation occurred de novo. Our study confirmed that abnormalities of the α1α1α2 heterotrimers of type IV collagen cause porencephaly and stresses the importance of screening for COL4A2 as well as for COL4A1. PMID:22209246

  4. Long-pulsed Nd:YAG laser-assisted hair removal in Fitzpatrick skin types IV-VI.

    PubMed

    Rao, Krishna; Sankar, Thangasamy K

    2011-09-01

    Unwanted hair is a common problem for which a variety of laser treatments is available. Laser treatment in dark-skinned individuals carries a higher risk of complications like hyperpigmentation and burn. The objective of this study was to evaluate efficacy and safety profile of laser-assisted hair removal in individuals with Fitzpatrick type IV-VI skin using long-pulsed Nd:YAG laser. Retrospective data was collected from 150 individuals with Fitzpatrick type IV-VI skin who underwent laser-assisted hair removal. This included area treated, fluence, number of treatments, and outcome. Data was also gathered on patient satisfaction and complications. The most common phototype was type IV (94%). The most frequently treated area was the face (84.7%) followed by the underarms and legs. Among the facial areas, the chin was the most frequently treated area followed by the upper lip and jaw line. The mean number of treatments was 8.9 (range 4-22). The maximum fluence averaged 26.8 Joules/cm(2) and was significantly higher for facial hair. Of the patients, 78.7% felt that their treatment was good or satisfactory. Mean hair reduction was 54.3%. Satisfaction from the treatment was significantly higher in individuals undergoing treatment of non-facial areas. Subsequent hair growth was slower and finer in 79.3% of the patients. There were no complications in 86% of the patients. All the complications were transient, with hyperpigmentation being the most frequent complication. Our results show that laser hair removal using the long-pulsed Nd:YAG laser is safe and effective in dark-skinned individuals with satisfactory results in most patients.

  5. Formation Mechanism of Type IV Failure in High Cr Ferritic Heat-Resistant Steel-Welded Joint

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Tsukamoto, S.; Shirane, T.; Abe, F.

    2013-10-01

    The mechanism of type IV failure has been investigated by using a conventional 9Cr ferritic heat-resistant steel Gr.92. In order to clarify the main cause of type IV failure, different heat treatments were performed on the base metal in order to change the prior austenite grain (PAG) size and precipitate distribution after applying the heat-affected zone (HAZ) simulated thermal cycle at the peak temperature of around A c3 ( A c3 HAZ thermal cycle) and postweld heat treatment (PWHT). The microstructural evolution during the A c3 HAZ thermal cycle and PWHT was investigated by means of scanning electron microscope (SEM), electron backscatter diffraction (EBSD), electron probe microanalysis (EPMA), and transmission electron microscope (TEM). It was found that M23C6 carbides were scarcely precipitated at the newly formed fine PAG, block, and lath boundaries in A c3 HAZ-simulated Gr.92, because the carbide forming elements such as Cr and C were segregated at the former PAG and block boundaries of the base metal. On the other hand, if all the boundaries were covered by sufficient M23C6 carbides by homogenization of the alloying elements prior to applying the HAZ thermal cycle, the creep strength was much improved even if the fine PAG was formed. From these results, it is concluded that fine-grained microstructure cannot account for the occurrence of type IV failure, and it only has a small effect during long-term creep. The most important factor is the precipitate formation behavior at various boundaries. Without sufficient boundary strengthening by precipitates, the microstructure of A c3 HAZ undergoes severe changes even during PWHT and causes premature failure during creep.

  6. Early-onset fetal hydrops and muscle degeneration in siblings due to a novel variant of type IV glycogenosis.

    PubMed

    Cox, P M; Brueton, L A; Murphy, K W; Worthington, V C; Bjelogrlic, P; Lazda, E J; Sabire, N J; Sewry, C A

    1999-09-10

    We report on 3 consecutive sib fetuses, presenting at 13, 12, and 13 weeks of gestation, respectively, with fetal hydrops, limb contractures, and akinesia. Autopsy of the first fetus showed subcutaneous fluid collections and severe degeneration of skeletal muscle. Histologic studies demonstrated massive accumulation of diastase-resistant periodic acid-Schiff-positive material in the skeletal muscle cells and epidermal keratinocytes of all 3 fetuses. Enzyme studies of fibroblasts from the 3rd fetus showed deficient activity of glycogen brancher enzyme, indicating that this is a new, severe form of glycogenosis type IV with onset in the early second trimester.

  7. 2- and 3-substituted imidazo[1,2-a]pyrazines as inhibitors of bacterial type IV secretion

    PubMed Central

    Sayer, James R.; Walldén, Karin; Pesnot, Thomas; Campbell, Frederick; Gane, Paul J.; Simone, Michela; Koss, Hans; Buelens, Floris; Boyle, Timothy P.; Selwood, David L.; Waksman, Gabriel; Tabor, Alethea B.

    2014-01-01

    A novel series of 8-amino imidazo[1,2-a]pyrazine derivatives has been developed as inhibitors of the VirB11 ATPase HP0525, a key component of the bacterial type IV secretion system. A flexible synthetic route to both 2- and 3-aryl substituted regioisomers has been developed. The resulting series of imidazo[1,2-a]pyrazines has been used to probe the structure–activity relationships of these inhibitors, which show potential as antibacterial agents. PMID:25438770

  8. Evidence that a modified type IV pilus-like system powers gliding motility and polysaccharide secretion in filamentous cyanobacteria.

    PubMed

    Khayatan, Behzad; Meeks, John C; Risser, Douglas D

    2015-12-01

    In filamentous cyanobacteria, the mechanism of gliding motility is undefined but posited to be driven by a polysaccharide secretion system known as the junctional pore complex (JPC). Recent evidence implies that the JPC is a modified type IV pilus-like structure encoded for in part by genes in the hps locus. To test this hypothesis, we conducted genetic, cytological and comparative genomics studies on hps and pil genes in Nostoc punctiforme, a species in which motility is restricted to transiently differentiated filaments called hormogonia. Inactivation of most hps and pil genes abolished motility and abolished or drastically reduced secretion of hormogonium polysaccharide, and the subcellular localization of several Pil proteins in motile hormogonia corresponds to the site of the junctional pore complex. The non-motile ΔhpsE-G strain, which lacks three glycosyltransferases that synthesize hormogonium polysaccharide, could be complemented to motility by the addition of medium conditioned by wild-type hormogonia. Based on this result, we speculate that secretion of hormogonium polysaccharide facilitates but does not provide the motive force for gliding. Both the Hps and Pil homologs characterized in this study are almost universally conserved among filamentous cyanobacteria, with the Hps homologs rarely found in unicellular strains. These results support the theory that Hps and Pil proteins compose the JPC, a type IV pilus-like nanomotor that drives motility and polysaccharide secretion in filamentous cyanobacteria.

  9. Modulation of Kingella kingae Adherence to Human Epithelial Cells by Type IV Pili, Capsule, and a Novel Trimeric Autotransporter

    PubMed Central

    Porsch, Eric A.; Kehl-Fie, Thomas E.; Geme, Joseph W. St.

    2012-01-01

    ABSTRACT Kingella kingae is an emerging bacterial pathogen that is being recognized increasingly as an important etiology of septic arthritis, osteomyelitis, and bacteremia, especially in young children. Colonization of the posterior pharynx is a key step in the pathogenesis of K. kingae disease. Previous work established that type IV pili are necessary for K. kingae adherence to the respiratory epithelium. In this study, we set out to identify additional factors that influence K. kingae interactions with human epithelial cells. We found that genetic disruption of the gene encoding a predicted trimeric autotransporter protein called Knh (Kingella NhhA homolog) resulted in reduced adherence to human epithelial cells. In addition, we established that K. kingae elaborates a surface-associated polysaccharide capsule that requires a predicted ABC-type transporter export operon called ctrABCD for surface presentation. Furthermore, we discovered that the presence of a surface capsule interferes with Knh-mediated adherence to human epithelial cells by nonpiliated organisms and that maximal adherence in the presence of a capsule requires the predicted type IV pilus retraction machinery, PilT/PilU. On the basis of the data presented here, we propose a novel adherence mechanism that allows K. kingae to adhere efficiently to human epithelial cells while remaining encapsulated and more resistant to immune clearance. PMID:23093386

  10. A rationalization of the Type IV loading dependence in the Kärger-Pfeifer classification of self-diffusivities

    SciTech Connect

    Krishna, Rajamani; van Baten, Jasper M.

    2011-01-08

    Kärger and Pfeifer (1987) have listed five different types of dependencies of the self-diffusivities, Di,self, on the loading, Θl, of guest molecules in zeolites. Of these five types, the Type IV dependence is particularly intriguing because it displays a maximum in the Di,self - Θl dependence for FAU zeolite. On the basis of published experimental data, and molecular simulations, for a variety of guest–host combinations we present arguments to suggest that the reasons for the curious maximum can be traced to molecular clustering. The clustering can be caused due to hydrogen bonding effects as is the case for methanol diffusion in NaY, or due to the temperatures being lower than the critical temperature, Tc.

  11. T346Hunter: A Novel Web-Based Tool for the Prediction of Type III, Type IV and Type VI Secretion Systems in Bacterial Genomes

    PubMed Central

    Martínez-García, Pedro Manuel; Ramos, Cayo; Rodríguez-Palenzuela, Pablo

    2015-01-01

    T346Hunter (Type Three, Four and Six secretion system Hunter) is a web-based tool for the identification and localisation of type III, type IV and type VI secretion systems (T3SS, T4SS and T6SS, respectively) clusters in bacterial genomes. Non-flagellar T3SS (NF-T3SS) and T6SS are complex molecular machines that deliver effector proteins from bacterial cells into the environment or into other eukaryotic or prokaryotic cells, with significant implications for pathogenesis of the strains encoding them. Meanwhile, T4SS is a more functionally diverse system, which is involved in not only effector translocation but also conjugation and DNA uptake/release. Development of control strategies against bacterial-mediated diseases requires genomic identification of the virulence arsenal of pathogenic bacteria, with T3SS, T4SS and T6SS being major determinants in this regard. Therefore, computational methods for systematic identification of these specialised machines are of particular interest. With the aim of facilitating this task, T346Hunter provides a user-friendly web-based tool for the prediction of T3SS, T4SS and T6SS clusters in newly sequenced bacterial genomes. After inspection of the available scientific literature, we constructed a database of hidden Markov model (HMM) protein profiles and sequences representing the various components of T3SS, T4SS and T6SS. T346Hunter performs searches of such a database against user-supplied bacterial sequences and localises enriched regions in any of these three types of secretion systems. Moreover, through the T346Hunter server, users can visualise the predicted clusters obtained for approximately 1700 bacterial chromosomes and plasmids. T346Hunter offers great help to researchers in advancing their understanding of the biological mechanisms in which these sophisticated molecular machines are involved. T346Hunter is freely available at http://bacterial-virulence-factors.cbgp.upm.es/T346Hunter. PMID:25867189

  12. AB152. The concomitant increase or decrease of several cytokines in prostatic secretion of patients with type-IIIA and type-IV prostatitis: the two subtypes of prostatitis may have a similar pathogenesis

    PubMed Central

    Wu, Chunlei; Mo, Zengnan

    2014-01-01

    Background Because the prevalence of chronic prostatitis (CP) subgroup can not be determined by routine epidemiologic methods (questionnaires), little research has been done with regard to each subtype of CP. In addition, further description of prostate cytokines may help to characterize the different types of prostatitis, and improve our understanding of the prostate immune responses in patients with type-IIIA, type-IIIB and type-IV CP. Methods and findings The study population comprised 2,887 men aged 18-78 years at second phase recruitment of a population-based cohort in China. The CP patients and healthy controls were defined by the National Institutes of Health Chronic Prostatitis Symptom Index. Meanwhile, EPS specimens were collected and the leukocyte in EPS was counted. We analyzed the levels of 47 cytokines in the EPS in 118 individuals (30/health, 30/type-IIIB, 29/type-IIIA, 29/type-III IV) randomly selected from present population. Prevalence of CP (26.78%/total, 1.49%/type-IIIA, 6.27%/type-IIIB and 19.02%/type-IV) is prevalent in China, and the prevalence of prostate inflammation (type-IIIA or type-IV CP) between the symptomatic men (type-IIIA/type-IIIA + IIIB, 19.20%) and asymptomatic men (type-IV/type-IV + health, 20.62%) is similar. While IL-1β, IL-6, IL-8, IL-15, IL-17, basic FGF, G-CSF, MCP-1, MIP-1α, MIP-1β, TNF-α, IL-1α, IL-16 and IL-18 levels were much higher in the type-IIIA and type-IV patient groups than in the type-IIIB and control groups, the levels of GM-CSF, PDGF-BB, SCGF-β and TNF-β was significantly lower in the type-IIIA and type-IV groups. The level of IL-1ra was clearly lower in the type-IIIB group, but LIF and β-NGF were elevated in type-IIIB groups of patients compared to controls type-IIIA and type-IV groups. Conclusions We think that type-IIIA and type-IV CP may have a similar pathogenesis, but type-IIIB CP may be a different disease with different pathogenesis.

  13. Expression of Kingella kingae Type IV Pili Is Regulated by σ54, PilS, and PilR▿

    PubMed Central

    Kehl-Fie, Thomas E.; Porsch, Eric A.; Miller, Sara E.; StGeme, Joseph W.

    2009-01-01

    Kingella kingae is a member of the Neisseriaceae and is being recognized increasingly as an important cause of serious disease in children. Recent work has demonstrated that K. kingae expresses type IV pili that mediate adherence to respiratory epithelial and synovial cells and are selected against during invasive disease. In the current study, we examined the genome of K. kingae strain 269-492 and identified homologs of the rpoN and the pilS and pilR genes that are essential for pilus expression in Pseudomonas aeruginosa but not in the pathogenic Neisseria species. The disruption of either rpoN or pilR in K. kingae resulted in a marked reduction in the level of transcript for the major pilus subunit (pilA1) and eliminated piliation. In contrast, the disruption of pilS resulted in only partial reduction in the level of pilA1 transcript and a partial decrease in piliation. Furthermore, the disruption of pilS in colony variants with high-density piliation resulted in variants with low-density piliation. Mutations in the promoter region of pilA1 and gel shift analysis demonstrated that both σ54 and PilR act directly at the pilA1 promoter, with PilR binding to two repetitive elements. These data suggest that the regulation of K. kingae type IV pilus expression is complex and multilayered, influenced by both the genetic state and environmental cues. PMID:19465661

  14. ESCRT-Dependent Cell Death in a Caenorhabditis elegans Model of the Lysosomal Storage Disorder Mucolipidosis Type IV.

    PubMed

    Huynh, Julie M; Dang, Hope; Munoz-Tucker, Isabel A; O'Ketch, Marvin; Liu, Ian T; Perno, Savannah; Bhuyan, Natasha; Crain, Allison; Borbon, Ivan; Fares, Hanna

    2016-02-01

    Mutations in MCOLN1, which encodes the cation channel protein TRPML1, result in the neurodegenerative lysosomal storage disorder Mucolipidosis type IV. Mucolipidosis type IV patients show lysosomal dysfunction in many tissues and neuronal cell death. The ortholog of TRPML1 in Caenorhabditis elegans is CUP-5; loss of CUP-5 results in lysosomal dysfunction in many tissues and death of developing intestinal cells that results in embryonic lethality. We previously showed that a null mutation in the ATP-Binding Cassette transporter MRP-4 rescues the lysosomal defect and embryonic lethality of cup-5(null) worms. Here we show that reducing levels of the Endosomal Sorting Complex Required for Transport (ESCRT)-associated proteins DID-2, USP-50, and ALX-1/EGO-2, which mediate the final de-ubiquitination step of integral membrane proteins being sequestered into late endosomes, also almost fully suppresses cup-5(null) mutant lysosomal defects and embryonic lethality. Indeed, we show that MRP-4 protein is hypo-ubiquitinated in the absence of CUP-5 and that reducing levels of ESCRT-associated proteins suppresses this hypo-ubiquitination. Thus, increased ESCRT-associated de-ubiquitinating activity mediates the lysosomal defects and corresponding cell death phenotypes in the absence of CUP-5.

  15. The effects of a liquid dispersing agent and a microcrystalline additive on the physical properties of type IV gypsum.

    PubMed

    Zakaria, M R; Johnston, W M; Reisbick, M H; Campagni, W V

    1988-11-01

    This study evaluated the effects of a liquid dispersing agent (LDA) and a microcrystalline additive (MCA) on selected physical properties of type IV gypsum. Working consistency, setting time, setting expansion, and compressive strength (1 hour and 7 days) were determined, following ADA Specification No. 25, on a standard, LDA (0.5, 1, 1.5, and 2 mL), MCA (21.1, 24.1, and 27.1 gm), and combination (LDA 0.75 mL + MCA 12.05 gm) mixes per 300 gm of gypsum. Results indicate that the additives affect the consistency of the mix, but consistency can be kept close to that of the standard by lowering the water/powder ratio. Statistical analysis of the data indicated that the additives significantly affected the setting time, setting expansion, and both the 1-hour and the 7-day compressive strengths. SEM examination of fractured surfaces of test mixes indicated improved crystal packing. The properties of type IV gypsum can be improved by optimizing the amount of LDA and MCA additives.

  16. Identification, immunogenicity, and cross-reactivity of type IV pilin and pilin-like proteins from Clostridium difficile.

    PubMed

    Maldarelli, Grace A; De Masi, Leon; von Rosenvinge, Erik C; Carter, Mihaela; Donnenberg, Michael S

    2014-08-01

    The Gram-positive anaerobe Clostridium difficile is the major cause of nosocomial diarrhea; manifestations of infection include diarrhea, pseudomembranous colitis, and death. Genes for type IV pili, a bacterial nanofiber often involved in colonization and until relatively recently described only in Gram-negatives, are present in all members of the Clostridiales. We hypothesized that any pilins encoded in the C. difficile genome would be immunogenic, as has been shown with pilins from Gram-negative organisms. We describe nine pilin or pilin-like protein genes, for which we introduce a coherent nomenclature, in the C. difficile R20291 genome. The nine predicted pilin or pilin-like proteins have relatively conserved N-terminal hydrophobic regions, but diverge at their C-termini. Analysis of synonymous and nonsynonymous substitutions revealed evidence of diversifying selective pressure in two pilin genes. Six of the nine identified proteins were purified and used to immunize mice. Immunization of mice with each individual protein generated antibody responses that varied in titer and cross-reactivity, a notable result given the low amino acid sequence identity among the pilins. Further studies in other small mammals mirrored our results in mice. Our results illuminate components of the C. difficile type IV pilus and help identify targets for an anti-C. difficile vaccine.

  17. ESCRT-Dependent Cell Death in a Caenorhabditis elegans Model of the Lysosomal Storage Disorder Mucolipidosis Type IV

    PubMed Central

    Huynh, Julie M.; Dang, Hope; Munoz-Tucker, Isabel A.; O’Ketch, Marvin; Liu, Ian T.; Perno, Savannah; Bhuyan, Natasha; Crain, Allison; Borbon, Ivan; Fares, Hanna

    2016-01-01

    Mutations in MCOLN1, which encodes the cation channel protein TRPML1, result in the neurodegenerative lysosomal storage disorder Mucolipidosis type IV. Mucolipidosis type IV patients show lysosomal dysfunction in many tissues and neuronal cell death. The ortholog of TRPML1 in Caenorhabditis elegans is CUP-5; loss of CUP-5 results in lysosomal dysfunction in many tissues and death of developing intestinal cells that results in embryonic lethality. We previously showed that a null mutation in the ATP-Binding Cassette transporter MRP-4 rescues the lysosomal defect and embryonic lethality of cup-5(null) worms. Here we show that reducing levels of the Endosomal Sorting Complex Required for Transport (ESCRT)-associated proteins DID-2, USP-50, and ALX-1/EGO-2, which mediate the final de-ubiquitination step of integral membrane proteins being sequestered into late endosomes, also almost fully suppresses cup-5(null) mutant lysosomal defects and embryonic lethality. Indeed, we show that MRP-4 protein is hypo-ubiquitinated in the absence of CUP-5 and that reducing levels of ESCRT-associated proteins suppresses this hypo-ubiquitination. Thus, increased ESCRT-associated de-ubiquitinating activity mediates the lysosomal defects and corresponding cell death phenotypes in the absence of CUP-5. PMID:26596346

  18. Expression and localization of laminin 5, laminin 10, type IV collagen, and amelotin in adult murine gingiva.

    PubMed

    Sawada, Takashi; Yamazaki, Takaki; Shibayama, Kazuko; Kumazawa, Kaido; Yamaguchi, Yoko; Ohshima, Mitsuhiro

    2014-06-01

    The biochemical composition of the internal and external basal laminae in the junctional epithelium differs significantly, and the precise cellular origin of their respective molecules remains to be determined. In the present study, the expression and localization of three basement membrane-specific molecules-laminin 5 (γ2 chain), type IV collagen (α1 chain), and laminin 10 (α5 chain)-and one tooth-specific molecule, amelotin, was analyzed in adult murine gingiva by using in situ hybridization and immunohistochemistry. The results showed that the outermost cells in junctional epithelium facing the tooth enamel strongly expressed laminin 5 mRNA, supporting the immunohistochemical staining data. This suggests that laminin 5 is actively synthesized in junctional epithelial cells and that the products are incorporated into the internal basal lamina to maintain firm epithelial adhesion to the tooth enamel throughout life. Conversely, no amelotin mRNA signals were detected in the junctional epithelial cells, suggesting that the molecules localized on the internal basal lamina are mainly derived from maturation-stage ameloblasts. Weak and sporadic expression of type IV collagen in addition to laminin 10 in the gingiva indicates that these molecules undergo turnover less frequently in adult animals.

  19. Human Type IV P-type ATPases That Work as Plasma Membrane Phospholipid Flippases and Their Regulation by Caspase and Calcium*

    PubMed Central

    Segawa, Katsumori; Kurata, Sachiko; Nagata, Shigekazu

    2016-01-01

    In plasma membranes, flippases translocate aminophospholipids such as phosphatidylserine and phosphatidylethanolamine from the extracellular to the cytoplasmic leaflet. Mammalian ATP11C, a type IV P-type ATPase, acts as a flippase at the plasma membrane. Here, by expressing 12 human type IV P-type ATPases in ATP11C-deficient cells, we determined that ATP8A2 and ATP11A can also act as plasma membrane flippases. As with ATP11C, ATP8A2 and ATP11A localized to the plasma membrane in a CDC50A-dependent manner. ATP11A was cleaved by caspases during apoptosis, and a caspase-resistant ATP11A blocked apoptotic PtdSer exposure. In contrast, ATP8A2 was not cleaved by caspase, and cells expressing ATP8A2 did not expose PtdSer during apoptosis. Similarly, high Ca2+ concentrations inhibited the ATP11A and ATP11C PtdSer flippase activity, but ATP8A2 flippase activity was relatively resistant to Ca2+. ATP11A and ATP11C were ubiquitously expressed in human and mouse adult tissues. In contrast, ATP8A2 was expressed in specific tissues, such as the brain and testis. Thus, ATP8A2 may play a specific role in translocating PtdSer in these tissues. PMID:26567335

  20. The involvement of the PilQ secretin of type IV pili in phage infection in Ralstonia solanacearum.

    PubMed

    Narulita, Erlia; Addy, Hardian Susilo; Kawasaki, Takeru; Fujie, Makoto; Yamada, Takashi

    2016-01-22

    PilQ is a member of the secretin family of outer membrane proteins and specifically involved in type IV secretion. Here we report the effects of pilQ mutation in Ralstonia solanacearum on the host physiology including susceptibility to several phage types (Inoviridae, Podoviridae and Myoviridae). With three lines of cells, namely wild type, ΔpilQ and pilQ-complemented cells, the cell surface proteins, twitching motility and sensitivity to phages were compared. SDS-PAGE analysis revealed that the major TFP pilin (PilA) was specifically lost in pilQ mutants and was recovered in the complemented cells. Drastically inactivated twitching motility in pilQ mutants was recovered to the wild type level in the complemented cells. Several phages of different types including those of Inoviridae, Podoviridae, and Myoviridae that infect wild type cells could not form plaques on pilQ mutants but showed infectivity to pilQ-complemented cells. These results indicate that PilQ function is generally required for phage infection in R. solanacearum.

  1. A spider toxin, ω-agatoxin IV A, binds to fixed as well as living tissues: cytochemical visualization of P/Q-type calcium channels.

    PubMed

    Nakanishi, Setsuko

    2016-08-01

    ω-Agatoxin IV A, a peptidyl toxin from Agelenopsis aperta venom, selectively binds to voltage-gated P/Q-type calcium channels. ω-Agatoxin IV A has been used as a selective tool in pharmacological and electrophysiological studies. Visualization of P/Q-type calcium channels has previously been accomplished using biotin-conjugated ω-Agatoxin IV A in freshly prepared mouse cerebellar and hippocampal slices (Nakanishi et al, J. Neurosci. Res., 41: , 532, 1995). Here biotinylated ω-agatoxin IV A was applied to transcardially fixed brain slices prepared with various fixatives. ω-Agatoxin IV A did not bind to fixed tissues from P/Q-type calcium channel knockout mice, confirming that binding to normal, fixed tissues was not an artifact. Using transmission electron microscopy, locations of biotinylated ω-agatoxin IV A binding sites visualized with gold-conjugated streptavidin showed a similar pattern to those visualized with antibody. The ability of biotinylated ω-agatoxin IV A to bind to fixed tissue provides a new cytochemical technique to study molecular architecture of synapses.

  2. Altered spatiotemporal expression of collagen types I, III, IV, and VI in Lpar3-deficient peri-implantation mouse uterus.

    PubMed

    Diao, Honglu; Aplin, John D; Xiao, Shuo; Chun, Jerold; Li, Zuguo; Chen, Shiyou; Ye, Xiaoqin

    2011-02-01

    Lpar3 is upregulated in the preimplantation uterus, and deletion of Lpar3 leads to delayed uterine receptivity in mice. Microarray analysis revealed that there was higher expression of Col3a1 and Col6a3 in the Preimplantation Day 3.5 Lpar3(-/-) uterus compared to Day 3.5 wild-type (WT) uterus. Since extracellular matrix (ECM) remodeling is indispensable during embryo implantation, and dynamic spatiotemporal alteration of specific collagen types is part of this process, this study aimed to characterize the expression of four main uterine collagen types: fibril-forming collagen (COL) I and COL III, basement membrane COL IV, and microfibrillar COL VI in the peri-implantation WT and Lpar3(-/-) uterus. An observed delay of COL III and COL VI clearance in the Lpar3(-/-) uterus may be associated with higher preimplantation expression of Col3a1 and Col6a3. There was also delayed clearance of COL I and delayed deposition of COL IV in the decidual zone in the Lpar3(-/-) uterus. These changes were different from the effects of 17beta-estradiol and progesterone on uterine collagen expression in ovariectomized WT uterus, indicating that the altered collagen expression in Lpar3(-/-) uterus is unlikely to be a result of alterations in ovarian hormones. Decreased expression of several genes encoding matrix-degrading metallo- and serine proteinases was observed in the Lpar3(-/-) uterus. These results demonstrate that pathways downstream of LPA3 are involved in the dynamic remodeling of ECM in the peri-implantation uterus.

  3. Tissue-engineered cartilaginous constructs for the treatment of caprine cartilage defects, including distribution of laminin and type IV collagen.

    PubMed

    Jeng, Lily; Hsu, Hu-Ping; Spector, Myron

    2013-10-01

    The purpose of this study was the immunohistochemical evaluation of (1) cartilage tissue-engineered constructs; and (2) the tissue filling cartilage defects in a goat model into which the constructs were implanted, particularly for the presence of the basement membrane molecules, laminin and type IV collagen. Basement membrane molecules are localized to the pericellular matrix in normal adult articular cartilage, but have not been examined in tissue-engineered constructs cultured in vitro or in tissue filling cartilage defects into which the constructs were implanted. Cartilaginous constructs were engineered in vitro using caprine chondrocyte-seeded type II collagen scaffolds. Autologous constructs were implanted into 4-mm-diameter defects created to the tidemark in the trochlear groove in the knee joints of skeletally mature goats. Eight weeks after implantation, the animals were sacrificed. Constructs underwent immunohistochemical and histomorphometric evaluation. Widespread staining for the two basement membrane molecules was observed throughout the extracellular matrix of in vitro and in vivo samples in a distribution unlike that previously reported for cartilage. At sacrifice, 70% of the defect site was filled with reparative tissue, which consisted largely of fibrous tissue and some fibrocartilage, with over 70% of the reparative tissue bonded to the adjacent host tissue. A novel finding of this study was the observation of laminin and type IV collagen in in vitro engineered cartilaginous constructs and in vivo cartilage repair samples from defects into which the constructs were implanted, as well as in normal caprine articular cartilage. Future work is needed to elucidate the role of basement membrane molecules during cartilage repair and regeneration.

  4. TYPE II CEPHEID CANDIDATES. IV. OBJECTS FROM THE NORTHERN SKY VARIABILITY SURVEY

    SciTech Connect

    Schmidt, Edward G.

    2013-09-15

    We have obtained VR photometry of 447 Cepheid variable star candidates with declinations north of -14 Degree-Sign 30', most of which were identified using the Northern Sky Variability Survey (NSVS) data archive. Periods and other photometric properties were derived from the combination of our data with the NSVS data. Atmospheric parameters were determined for 81 of these stars from low-resolution spectra. The identification of type II Cepheids based on the data presented in all four papers in this series is discussed. On the basis of spectra, 30 type II Cepheids were identified while 53 variables were identified as cool, main sequence stars and 283 as red giants following the definitions in Paper III. An additional 30 type II Cepheids were identified on the basis of light curves. The present classifications are compared with those from the Machine-learned All Sky Automated Survey Classification Catalog for 174 stars in common.

  5. Galactic cannibalism. IV. The evidence-correlations between dynamical time scales and Bautz-Morgan type

    SciTech Connect

    McGlynn, T.A.; Ostriker, J.P.

    1980-11-01

    If the luminosity of supergiant cD galaxies in particular, and the Bautz-Morgan sequence of galaxy types in general, is produced by dynamical evolutionary processes, then one expects to find a correlation between dynamical times and ..delta..M/sub 12/, the magnitude difference between first and second brightest cluster members.

  6. Role of type IV pili in virulence of Pseudomonas syringae pv. tabaci 6605: correlation of motility, multidrug resistance, and HR-inducing activity on a nonhost plant.

    PubMed

    Taguchi, Fumiko; Ichinose, Yuki

    2011-09-01

    To investigate the role of type IV pili in the virulence of phytopathogenic bacteria, four mutant strains for pilus biogenesis-related genes were generated in Pseudomonas syringae pv. tabaci 6605. PilA encodes the pilin protein as a major subunit of type IV pili, and the pilO product is reported to be required for pilus assembly. The fimU and fimT genes are predicted to produce minor pilins. Western blot analysis revealed that pilA, pilO, and fimU mutants but not the fimT mutant failed to construct type IV pili. Although the swimming motility of all mutant strains was not impaired in liquid medium, they showed remarkably reduced motilities on semisolid agar medium, suggesting that type IV pili are required for surface motilities. Virulence toward host tobacco plants and hypersensitive response-inducing ability in nonhost Arabidopsis leaves of pilA, pilO, and fimU mutant strains were reduced. These results might be a consequence of reduced expression of type III secretion system-related genes in the mutant strains. Further, all mutant strains showed enhanced expression of resistance-nodulation-division family members mexA, mexB, and oprM, and higher tolerance to antimicrobial compounds. These results indicate that type IV pili are an important virulence factor of this pathogen.

  7. Anti-inflammatory and bronchodilator properties of RP 73401, a novel and selective phosphodiesterase type IV inhibitor

    PubMed Central

    Raeburn, David; Underwood, Stephen L.; Lewis, Susan A.; Woodman, Valerie R.; Battram, Cliff H.; Tomkinson, Adrian; Sharma, Steven; Jordan, Roy; Souness, John E.; Webber, Stephen E.; Karlsson, Jan-Anders

    1994-01-01

    1 We have investigated the effects of RP 73401, a novel, potent and highly selective cyclic nucleotide phosphodiesterase (PDE) type IV inhibitor, in guinea-pig and rat models of bronchoconstriction and allergic inflammation. In some models, the effects of RP 73401 have been compared with those of the standard PDE type IV inhibitor, rolipram. 2 RP 73401 (0.4-400 μg kg-1, intratracheally (i.t.) on lactose) inhibited antigen-induced bronchospasm in previously sensitized conscious guinea-pigs (ID50: 7±1 μg kg-1) and in anaesthetized rats (ID50: 100±25 μg kg-1). Rolipram inhibited the antigen-induced bronchospasm in guinea-pigs with an ID50 of 5±1 μg kg-1. In guinea-pig bronchoalveolar lavage (BAL) fluid, total inflammatory cell and eosinophil numbers were reduced by RP 73401 (ID50S: 3.9±0.8 μg kg-1 and 3.2±0.7 μg kg-1, respectively). In the rat, inflammatory cell numbers are less affected. Only the highest dose of RP 73401 (400 μg kg-1) significantly inhibited eosinophil influx (41±16% inhibition). 3 RP 73401 (0.02-100 μg kg-1, i.v.) inhibited PAF-induced bronchial hyperreactivity to bombesin in the anaesthetized guinea-pig (ID50: 0.09±0.03 μg kg-1) and inhibited (0.4-40 μg kg-1, i.t.) histamine-induced airway microvascular leakage in the anaesthetized guinea-pig by approximately 60% at all doses. 4 RP 73401 relaxed guinea-pig isolated trachea under basal tone (EC50: 9 nM) and when precontracted with histamine (IC50: 2 nM), methacholine (IC50: 29 nM) or leukotriene D4 (LTD4, IC50: 4 nM). 5 RP 73401 (0.4-100 μg kg-1, i.t.) inhibited bronchospasm induced by histamine (ID50: 34±6 μg kg-1), methacholine (ID50: 66±12 μg kg-1) and LTD4 (ID50: <4 μg kg-1) in the anaesthetized guinea-pig. Against these same bronchoconstrictors, rolipram (i.t.) had ID50 values of 44±4, 72±18 and <4 μg kg-1 respectively. RP 73401 (4 and 40 μg kg-1, i.t.) increased the magnitude and duration of bronchodilatation produced by salbutamol in the anaesthetized guinea-pig. At

  8. Type IV hypersensitivity reactions following Dermabond adhesive utilization in knee surgery: A Report of Three Cases.

    PubMed

    Yagnatovsky, Michelle; Pham, Hien; Rokito, Andrew; Jazrawi, Laith; Strauss, Eric

    2017-01-25

    ​We retrospectively reviewed the records of 3 patients (3 knees) with a delayed type hypersensitivity reaction following Dermabond exposure after an orthopaedic knee procedure. Delayed hypersensitivity reactions are mediated by CD4+ helper T cells. The use of skin adhesives in place of traditional sutures is increasing in popularity given Dermabond's potential benefits of decreased wound infection rate and better wound approximation. However, hypersensitivity reactions to the cyanoacrylate material in Dermabond have been described. Differentiating hypersensitivity reactions from post-operative infections is important as septic arthritis is a potentially devastating complication. This case series presents the challenge of properly diagnosing and managing hypersensitivity reactions. Consultation with allergists and dermatologists may be appropriate for ascertaining the nature of the surgical site complication and proper management. The recommended management of hypersensitivity-type reactions is a course of topical steroids and infection work up if needed.

  9. Immunohistochemical and ultrastructural changes in the brain in probable adult glycogenosis type IV: adult polyglucosan body disease.

    PubMed

    Wierzba-Bobrowicz, Teresa; Lewandowska, Eliza; Stepień, Tomasz; Modzelewska, Joanna

    2008-01-01

    Glycogenosis type IV is caused by a deficiency of glycogen branching enzyme (alpha-1,4 glucan 6-transglucosylase). Adult polyglucosan body disease (APBD) may represent a neuropathological hallmark of the adult form of this storage disease of the central nervous system. We analysed a case of a 45-year-old unconscious woman who died three days after admission to the hospital. Neuropathological examination revealed massive accumulation of polyglucosan bodies (PBs) in the cortex and white matter of the whole brain. PBs were located in the processes of neurons, astrocytes and microglial cells. The storage material in the cytoplasm of neurons and glial cells was visible as fine granules. Ultrastructurally, PBs consisted of non-membrane-bound deposits of branched and densely packed filaments, measuring about 7-10 nm in diameter, typical of polyglucosan bodies. APBD patients develop upper and lower neuron disease and dementia, probably secondary to the disruption of neuron and astrocyte functions.

  10. The BID Domain of Type IV Secretion Substrates Forms a Conserved Four-Helix Bundle Topped with a Hook.

    PubMed

    Stanger, Frédéric V; de Beer, Tjaart A P; Dranow, David M; Schirmer, Tilman; Phan, Isabelle; Dehio, Christoph

    2017-01-03

    The BID (Bep intracellular delivery) domain functions as secretion signal in a subfamily of protein substrates of bacterial type IV secretion (T4S) systems. It mediates transfer of (1) relaxases and the attached DNA during bacterial conjugation, and (2) numerous Bartonella effector proteins (Beps) during protein transfer into host cells infected by pathogenic Bartonella species. Furthermore, BID domains of Beps have often evolved secondary effector functions within host cells. Here, we provide crystal structures for three representative BID domains and describe a novel conserved fold characterized by a compact, antiparallel four-helix bundle topped with a hook. The conserved hydrophobic core provides a rigid scaffold to a surface that, despite a few conserved exposed residues and similarities in charge distribution, displays significant variability. We propose that the genuine function of BID domains as T4S signal may primarily depend on their rigid structure, while the plasticity of their surface may facilitate adaptation to secondary effector functions.

  11. Cell-mediated degradation of type IV collagen and gelatin films is dependent on the activation of matrix metalloproteinases.

    PubMed Central

    Atkinson, S J; Ward, R V; Reynolds, J J; Murphy, G

    1992-01-01

    The ability of normal rabbit dermal fibroblasts to degrade films of type IV collagen and gelatin when stimulated by phorbol ester was shown to be dependent on the induction, secretion and activation of 95 kDa gelatinase B and the secretion and activation of 72 kDa gelatinase A and stromelysin. Degradation was inhibited by exogenous human recombinant tissue inhibitor of metalloproteinases-1, specific antibodies to gelatinase and stromelysin and by the reactive-oxygen-metabolite inhibitor catalase. We discuss the various pathways for activation of matrix metalloproteinases in this model system and conclude that, although plasmin may play a key role in the activation of gelatinase B and stromelysin, gelatinase A is activated by a mechanism which has yet to be elucidated. The involvement of oxygen radicals in the direct activation of matrix metalloproteinases in this model is thought to be unlikely. Images Fig. 2. Fig. 3. Fig. 4. PMID:1463464

  12. Physeal fractures of the distal tibia and fibula (Salter-Harris Type I, II, III, and IV fractures).

    PubMed

    Podeszwa, David A; Mubarak, Scott J

    2012-06-01

    Physeal fractures of the distal tibia and fibula are common and can be seen at any age, although most are seen in the adolescent. An understanding of the unique anatomy of the skeletally immature ankle in relation to the mechanism of injury will help one understand the injury patterns seen in this population. A thorough clinical exam is critical to the diagnosis and treatment of these injuries and the avoidance of potentially catastrophic complications. Nondisplaced physeal fractures of the distal tibia and fibula can be safely treated nonoperatively. Displaced fractures should undergo a gentle reduction with appropriate anesthesia while multiple reduction attempts should be avoided. Gapping of the physis >3 mm after reduction should raise the suspicion of entrapped periosteum that will increase the risk of premature physeal closure. Open reduction of displaced Salter-Harris type III and IV fractures is critical to maintain joint congruity and minimize the risk of physeal arrest.

  13. Effect of immobilized collagen type IV on biological properties of endothelial cells for the enhanced endothelialization of synthetic vascular graft materials.

    PubMed

    Heo, Yunhoe; Shin, Young Min; Lee, Yu Bin; Lim, Youn Mook; Shin, Heungsoo

    2015-10-01

    Regeneration of healthy endothelium onto vascular graft materials is imperative for prevention of intimal hyperplasia and thrombogenesis. In this study, we investigated the effect of collagen type IV (COL-IV) immobilized onto electrospun nanofibers on modulation of endothelial cell (EC) function, as a potential signal to rapid endothelialization of vascular grafts. COL-IV is assembled in basement membrane underneath intimal layer and regulates morphogenesis of blood vessels. For immobilization of COL-IV, poly(l-lactic acid) (PLLA) nanofibers (PL) were prepared as a model vascular graft substrate, onto which acrylic acid (AAc) was then grafted by using gamma-ray irradiation. AAc graft was dependent on irradiation doses and AAc concentrations, which allowed us to select the condition of 5% (v/v) AAc and 10 kGy for further conjugation of COL-IV. COL-IV immobilization was proportionally controlled as a function of its concentration. Atomic force microscope (AFM) analysis qualitatively supported immobilization of COL-IV, demonstrating increase in root mean square roughness of the PL from 665.37 ± 13.20 nm to 1440.74 ± 33.24. However, the Young's modulus of nanofibers was retained as approximately 1 MPa, regardless of surface modification. The number of ECs attached on the nanofibers with immobilized COL-IV was significantly increased by 5 times (1052 ± 138 cells/mm(2)) from pristine PL (234 ± 41 cells/mm(2)). In addition, the effect of immobilized COL-IV was profound for enhancing proliferation and up-regulation of markers implicated in rapid endothelialization. Collectively, our results suggest that COL-IV immobilized onto electrospun PLLA nanofibers may serve as a promising instructive cue used in vascular graft materials.

  14. Comparative Evaluation of Dimensional Accuracy and Tensile Strength of a Type IV Gypsum Using Microwave and Air Drying Methods.

    PubMed

    Sharma, Anuraag; Shetty, Manoj; Hegde, Chethan; Shetty, N Sridhar; Prasad, D Krishna

    2013-12-01

    To evaluate dimensional accuracy and tensile strength of a type IV gypsum product, at different time intervals, dried in air or a microwave oven. Eighty specimens prepared from a cylindrical mould were used for measuring tensile strength (group A). Twenty specimens from a master die mould were used for determining dimensional accuracy (group B). In group A, 40 specimens were dried in open air at room temperature (A1). The other 40 were removed after 30 min and air dried for 20 min. These were subjected to microwave oven drying for 5 min (A2). Ten specimens each were tested under diametral compression at each of the following time periods: 1, 2, 4 and 24 h after drying. In group B, ten specimens were dried in open air at room temperature (B1). Ten specimens were removed from the mould after 30 min and air dried for 20 min. These were then dried in a microwave oven for 5 min (B2). The data was statistically analyzed using students unpaired "t" test. At all time intervals, diametral tensile strength (DTS) values for specimens dried in microwave oven were significantly higher than for those dried in open air. There were no significant differences between the dimensional accuracy of the two groups. In this study, microwave oven drying had a positive effect on the DTS of a type IV gypsum and the microwave oven dried specimens were as accurate as the air dried specimens over the same time period.

  15. Type IV resistant starch increases cecum short chain fatty acids level in rats.

    PubMed

    Le Thanh-Blicharz, Joanna; Anioła, Jacek; Kowalczewski, Przemysław; Przygoński, Krzysztof; Zaborowska, Zofia; Lewandowicz, Grażyna

    2014-01-01

    Resistant starches are type of dietary fibers. However, their physiological effects depend on the way they resist digestion in the gastrointestinal tract. The objective of this study was to examine the hypothesis that new type of RS4 preparations, of in vitro digestibility of about 50%, obtained by cross-linking and acetylation, acts as a prebiotic by increasing short chain fatty acids content in cecum digesta. The rats were fed with diet containing pregelatinized, cross-linked and acetylated starches as a main carbohydrate source. Pregelatinized, but not chemically modified, potato starch was used in the composition of the control diet. After two weeks of experiment the increase of short chain fatty acids contents in ceceum digesta was observed. The intake of starch A, cross-linked only with adipic acid, resulted in increase of about 40% of short chain fatty acids content, whereas starch PA cross-linked with sodium trimetaphosphate and adipic acid of about 50%. The utmost twofold increase was observed in the case of the production of propionic acid. In contrast, the content of butyric acid increased (12%) only as an effect of consumption of starch PA and even decreased (about 30%) in case of starch A. Both RS4 starches caused an increase of the production of acetic acid by more than 40%. No changes in serum biochemistry, liver cholesterol and organ weights of rats were stated.

  16. Nerve growth factor-tyrosine kinase A pathway is involved in thermoregulation and adaptation to stress: studies on patients with hereditary sensory and autonomic neuropathy type IV.

    PubMed

    Loewenthal, Neta; Levy, Jacov; Schreiber, Ruth; Pinsk, Vered; Perry, Zvi; Shorer, Zamir; Hershkovitz, Eli

    2005-04-01

    Hereditary sensory and autonomic neuropathy type IV (HSAN IV) is caused by mutations in the tyrosin kinase A (TrkA) gene, encoding for the high-affinity receptor of nerve growth factor (NGF). The NGF-TrkA system is expressed in many endocrine glands. We hypothesized that HSAN IV represents a natural model for impaired NGF effect on the neuroendocrine system in humans. We have documented the clinical outcome of 31 HSAN IV patients in a single medical center, and investigated their basal endocrine system status. The endocrine system response to thirst was compared between six patients and six healthy children. High rates of mortality (22%) and severe morbidity (30%) have been found in HSAN IV patients. Hypothermia was noted in 40% of the patients and unexplained fever was observed in 56%. Subnormal adrenal function was demonstrated in six (30%) of the patients studied. Furthermore, we found lower plasma norepinephrine (NE) levels in six HSAN IV patients compared with a control group after the thirst test. Our findings emphasize the importance of NGF-TrkA pathway in the physiology of the neuroendocrine system and its response to stress. Inadequate response to stress might contribute to the observed significant mortality, morbidity, and temperature instability in HSAN IV patients.

  17. Massive stars exploding in a He-rich circumstellar medium - IV. Transitional Type Ibn supernovae

    NASA Astrophysics Data System (ADS)

    Pastorello, A.; Benetti, S.; Brown, P. J.; Tsvetkov, D. Y.; Inserra, C.; Taubenberger, S.; Tomasella, L.; Fraser, M.; Rich, D. J.; Botticella, M. T.; Bufano, F.; Cappellaro, E.; Ergon, M.; Gorbovskoy, E. S.; Harutyunyan, A.; Huang, F.; Kotak, R.; Lipunov, V. M.; Magill, L.; Miluzio, M.; Morrell, N.; Ochner, P.; Smartt, S. J.; Sollerman, J.; Spiro, S.; Stritzinger, M. D.; Turatto, M.; Valenti, S.; Wang, X.; Wright, D. E.; Yurkov, V. V.; Zampieri, L.; Zhang, T.

    2015-05-01

    We present ultraviolet, optical and near-infrared data of the Type Ibn supernovae (SNe) 2010al and 2011hw. SN 2010al reaches an absolute magnitude at peak of MR = -18.86 ± 0.21. Its early light curve shows similarities with normal SNe Ib, with a rise to maximum slower than most SNe Ibn. The spectra are dominated by a blue continuum at early stages, with narrow P-Cygni He I lines indicating the presence of a slow-moving, He-rich circumstellar medium. At later epochs, the spectra well match those of the prototypical SN Ibn 2006jc, although the broader lines suggest that a significant amount of He was still present in the stellar envelope at the time of the explosion. SN 2011hw is somewhat different. It was discovered after the first maximum, but the light curve shows a double peak. The absolute magnitude at discovery is similar to that of the second peak (MR = -18.59 ± 0.25), and slightly fainter than the average of SNe Ibn. Though the spectra of SN 2011hw are similar to those of SN 2006jc, coronal lines and narrow Balmer lines are clearly detected. This indicates substantial interaction of the SN ejecta with He-rich, but not H-free, circumstellar material. The spectra of SN 2011hw suggest that it is a transitional SN Ibn/IIn event similar to SN 2005la. While for SN 2010al the spectrophotometric evolution favours a H-deprived Wolf-Rayet progenitor (of WN-type), we agree with the conclusion of Smith et al. that the precursor of SN 2011hw was likely in transition from a luminous blue variable to an early Wolf-Rayet (Ofpe/WN9) stage.

  18. Femtochemistry of Norrish type-I reactions: IV. Highly excited ketones--experimental.

    PubMed

    Sølling, Theis I; Diau, Eric W G; Kötting, Carsten; De Feyter, Steven; Zewail, Ahmed H

    2002-01-18

    Femtosecond dynamics of Norrish type-I reactions of cyclic and acyclic ketones have been investigated in real time for a series of 13 compounds using femtosecond-resolved time-of-flight mass spectrometry. A general physical description of the ultrafast processes of ketones excited into a high-lying Rydberg state is presented. It accounts not only for the results that are presented herein but also for the results of previously reported studies. For highly excited ketones, we show that the Norrish type-I reaction is nonconcerted, and that the first bond breakage occurs along the effectively repulsive S2 surface involving the C-C bond in a manner which is similar to that of ketones in the S1 state (E. W.-G. Diau et al. ChemPhysChem 2001, 2, 273-293). The experimental results show that the wave packet motion out of the initial Franck-Condon region and down to the S2 state can be resolved. This femtosecond (fs) internal conversion from the highly excited Rydberg state to the S2 state proceeds through conical intersections (Rydberg-valence) that are accessed through the C=O stretching motion. In one of these conical intersections, the internal energy is guided into an asymmetric stretching mode. This explains the previously reported pronounced nonstatistical nature of the reaction. The second bond breakage involves an excited-state acyl radical and occurs on a time scale that is up to one order of magnitude longer than the first. We discuss the details regarding the ion chemistry, which determines the appearance of the mass spectra that arise from ionization on the fs time scale. The experimental results presented here, aided by the theoretical work reported in paper III, provide a unified picture of Norrish reactions on excited states and on the ground-state potential energy surfaces.

  19. Column selectivity in reversed-phase liquid chromatography. IV. Type-B alkyl-silica columns.

    PubMed

    Gilroy, Jonathan J; Dolan, John W; Snyder, Lloyd R

    2003-06-06

    Columns for reversed-phase HPLC (RP-LC) can be characterized by five, retention-related parameters: H (hydrophobicity), S (steric selectivity), A (hydrogen-bond acidity), B (hydrogen-bond basicity), and C (cation-exchange behavior). In the present study, values of the latter parameters have been measured for 92 type-B (low metals content)alkyl-silica columns and compared to column properties such as ligand length,ligand concentration, pore diameter, and the presence or absence of end-capping. With the exception of five columns of unusual design, retention factors, k, for 16 representative test compounds were correlated with values of H, S, etc., within an average +/- 1.2% (1 standard deviation, SD), suggesting that all significant solute-column interactions are recognized by these five column parameters. A single-valued function F(s) is proposed to measure differences in selectivity for any two RP-LC columns whose values of H, S, etc., are known. This allows the easy selection of columns whose selectivity is desired to be either similar to or different from a starting column, for application in either routine analysis or method development.

  20. SVBR-100 module-type fast reactor of the IV generation for regional power industry

    NASA Astrophysics Data System (ADS)

    Zrodnikov, A. V.; Toshinsky, G. I.; Komlev, O. G.; Stepanov, V. S.; Klimov, N. N.

    2011-08-01

    In the report the following is presented: basic conceptual provisions of the innovative nuclear power technology (NPT) based on modular fast reactors (FR) SVBR-100, summarized results of calculations of the reactor, analysis of the opportunities of multi-purpose application of such reactor facilities (RF) including export potentials with due account of nonproliferation requirements. The most important features of the proposed NPT analyzed in the report are as follows: (1) integral (monoblock) arrangement of the primary circuit equipment with entire elimination of the primary circuit pipelines and valves that considerably reduces the construction and assembly works period and coupling with high boiling point of lead-bismuth coolant (LBC) deterministically eliminates accidents of the LOCA type, (2) option for 100 MWe power and dimensions of the reactor provide: on the one hand, an opportunity to transport the reactor monoblock in factory-readiness by railway as well as other kinds of transport, on the other hand, core breeding ratio (CBR) exceeds 1 while MOX-fuel is used. The preferable area of application of RF SVBR-100 is regional and small power requiring power-units of electric power in a range of (100-600) MW, which could be used for cogeneration-based district heating while locating them nearby cities as well as for generation of electric power in a mode of load tracking in the regions with low network systems.

  1. Immunohistochemical distribution of laminin-332 and collagen type IV in the basement membrane of normal horses and horses with induced laminitis.

    PubMed

    Visser, M B; Pollitt, C C

    2011-07-01

    The basement membrane (BM) is a thin layer of extracellular matrix that regulates cell functions as well as providing support to tissues of the body. Primary components of the BM of epithelial tissues are laminin-332 (Ln-332) and collagen type IV. Equine laminitis is a disease characterized by destruction and dislocation of the hoof lamellar BM. Immunohistochemistry was used to characterize the distribution of Ln-332 and collagen type IV in the organs of normal horses and these proteins were found to be widespread. Analysis of a panel of tissue samples from horses with experimentally-induced laminitis revealed that Ln-332 and collagen type IV degradation occurs in the skin and stomach in addition to the hoof lamellae. These findings suggest that BM degradation is common to many epithelial tissues during equine laminitis and suggests a role for systemic trigger factors in this disease.

  2. Autoimmunity to the alpha 3 chain of type IV collagen in glomerulonephritis is triggered by ‘autoantigen complementarity’

    PubMed Central

    Reynolds, John; Preston, Gloria A.; Pressler, Barrak M.; Hewins, Peter; Brown, Michael; Roth, Aleeza; Alderman, Elizabeth; Bunch, Donna; Jennette, J. Charles; Cook, H. Terence; Falk, Ronald J.; Pusey, Charles D.

    2015-01-01

    ‘Autoantigen complementarity’ is a theory proposing that the initiator of an autoimmune response is not necessarily the autoantigen or its molecular mimic, but may instead be a peptide that is ‘antisense/complementary’ to the autoantigen. We investigated whether such complementary proteins play a role in the immunopathogenesis of autoimmune glomerulonephritis. Experimental autoimmune glomerulonephritis, a model of anti-glomerular basement membrane (GBM) disease, can be induced in Wistar Kyoto (WKY) rats by immunization with the α3 chain of type IV collagen. In this study, WKY rats were immunized with a complementary α3 peptide (c-α3-Gly) comprised of amino acids that ‘complement’ the well characterized epitope on α3(IV)NC1, pCol(24–38). Within 8 weeks post-immunization, these animals developed cresentic glomerulonephritis, similar to pCol(24–38)-immunized rats, while animals immunized with scrambled peptide were normal. Anti-idiotypic antibodies to epitopes from c-α3-Gly-immunized animals were shown to be specific for α3 protein, binding in a region containing sense pCol(24–38) sequence. Interestingly, anticomplementary α3 antibodies were identified in sera from patients with anti-GBM disease, suggesting a role for ‘autoantigen complementarity’ in immunopathogenesis of the human disease. This work supports the idea that autoimmune glomerulonephritis can be initiated through an immune response against a peptide that is anti-sense or complementary to the autoantigen. The implications of this discovery may be far reaching, and other autoimmune diseases could be due to responses to these once unsuspected ‘complementary’ antigens. PMID:25841937

  3. Large Magellanic Cloud Near-infrared Synoptic Survey. IV. Leavitt Laws for Type II Cepheid Variables

    NASA Astrophysics Data System (ADS)

    Bhardwaj, Anupam; Macri, Lucas M.; Rejkuba, Marina; Kanbur, Shashi M.; Ngeow, Chow-Choong; Singh, Harinder P.

    2017-04-01

    We present time-series observations of Population II Cepheids in the Large Magellanic Cloud at near-infrared (JHK s ) wavelengths. Our sample consists of 81 variables with accurate periods and optical (VI) magnitudes from the OGLE survey, covering various subtypes of pulsators (BL Herculis, W Virginis, and RV Tauri). We generate light-curve templates using high-quality I-band data in the LMC from OGLE and K s -band data in the Galactic bulge from VISTA Variables in Via Láctea survey and use them to obtain robust mean magnitudes. We derive period–luminosity (P–L) relations in the near-infrared and Period–Wesenheit (P–W) relations by combining optical and near-infrared data. Our P–L and P–W relations are consistent with published work when excluding long-period RV Tauris. We find that Pop II Cepheids and RR Lyraes follow the same P–L relations in the LMC. Therefore, we use trigonometric parallax from the Gaia DR1 for VY Pyx and the Hubble Space Telescope parallaxes for k Pav and 5 RR Lyrae variables to obtain an absolute calibration of the Galactic K s -band P–L relation, resulting in a distance modulus to the LMC of {μ }{LMC}=18.54+/- 0.08 mag. We update the mean magnitudes of Pop II Cepheids in Galactic globular clusters using our light-curve templates and obtain distance estimates to those systems, anchored to a precise late-type eclipsing binary distance to the LMC. We find that the distances to these globular clusters based on Pop II Cepheids are consistent (within 2σ ) with estimates based on the {M}V-[{Fe}/{{H}}] relation for horizontal branch stars.

  4. EARLY-TYPE GALAXIES AT z {approx} 1.3. IV. SCALING RELATIONS IN DIFFERENT ENVIRONMENTS

    SciTech Connect

    Raichoor, A.; Mei, S.; Huertas-Company, M.; Stanford, S. A.; Rettura, A.; Jee, M. J.; Holden, B. P.; Illingworth, G.; Rosati, P.; Shankar, F.; Tanaka, M.; Ford, H.; Postman, M.; White, R. L.; Blakeslee, J. P.; Demarco, R.

    2012-02-01

    We present the Kormendy and mass-size relations (MSR) for early-type galaxies (ETGs) as a function of environment at z {approx} 1.3. Our sample includes 76 visually classified ETGs with masses 10{sup 10} < M/M{sub Sun} < 10{sup 11.5}, selected in the Lynx supercluster and in the Great Observatories Origins Deep Survey/Chandra Deep Field South field; 31 ETGs in clusters, 18 in groups, and 27 in the field, all with multi-wavelength photometry and Hubble Space Telescope/Advanced Camera for Surveys observations. The Kormendy relation, in place at z {approx} 1.3, does not depend on the environment. The MSR reveals that ETGs overall appear to be more compact in denser environments: cluster ETGs have sizes on average around 30%-50% smaller than those of the local universe and a distribution with a smaller scatter, whereas field ETGs show an MSR with a similar distribution to the local one. Our results imply that (1) the MSR in the field did not evolve overall from z {approx} 1.3 to present; this is interesting and in contrast to the trend found at higher masses from previous works; (2) in denser environments, either ETGs have increased in size by 30%-50% on average and spread their distributions, or more ETGs have been formed within the dense environment from non-ETG progenitors, or larger galaxies have been accreted to a pristine compact population to reproduce the MSR observed in the local universe. Our results are driven by galaxies with masses M {approx}< 2 Multiplication-Sign 10{sup 11} M{sub Sun} and those with masses M {approx} 10{sup 11} M{sub Sun} follow the same trends as that of the entire sample. Following the Valentinuzzi et al. definition of superdense ETGs, {approx}35%-45% of our cluster sample is made up of superdense ETGs.

  5. IFU spectroscopy of 10 early-type galactic nuclei- IV. Properties of the circumnuclear stellar kinematics

    NASA Astrophysics Data System (ADS)

    Ricci, T. V.; Steiner, J. E.; Menezes, R. B.

    2016-12-01

    The study of stellar kinematic properties may provide hints on the formation and evolution of elliptical and lenticular galaxies. Although most previous studies have focused on the large scale of these galaxies, their central regions (scales of ˜100 pc) may contain important clues about their structure, such as kinematically decoupled cores. This is the fourth paper on a sample of 10 massive (σ > 200 km s-1) and nearby (d < 31 Mpc) early-type galaxies, observed with the integral field unit of the Gemini South Multi Object Spectrograph. Here, we analyse the properties of the stellar kinematics in the circumnuclear region. We fitted the line-of-sight velocity distribution with a Gauss-Hermite function. In seven galaxies of the sample, we detected a rotation pattern in their radial velocity maps that are anti-correlated with h3. We interpret this as stellar structures in rotation embedded in the bulges of the objects. Comparing the stellar kinematic results with the PCA Tomography results and also with the gas kinematic results of IC 5181, it seems that this object may have a non-axisymmetric potential at its centre. The velocity dispersion maps of four objects have a nuclear peak, which must correspond, in part, to unresolved stellar rotation. In NGC 1404, we detected a kinematic decoupled core with an extension of ˜200 pc. This galaxy also has a σ-drop in the centre, which may be related to both stellar components in counter-rotation or with a kinematically cold star-forming region.

  6. Arctigenin, a phenylpropanoid dibenzylbutyrolactone lignan, inhibits type I-IV allergic inflammation and pro-inflammatory enzymes.

    PubMed

    Lee, Ji Yun; Kim, Chang Jong

    2010-06-01

    We previously reported that arctigenin, a phenylpropanoid dibenzylbutyrolactone lignan isolated from Forsythia koreana, exhibits anti-inflammatory, antioxidant, and analgesic effects in animal models. In addition, arctigenin inhibited eosinophil peroxidase and activated myeloperoxidase in inflamed tissues. In this study, we tested the effects of arctigenin on type I-IV allergic inflammation and pro-inflammatory enzymes in vitro and in vivo. Arctigenin significantly inhibited the heterologous passive cutaneous anaphylaxis induced by ovalbumin in mice at 15 mg/kg, p.o., and compound 48/80-induced histamine release from rat peritoneal mast cells at 10 microM. Arctigenin (15 mg/kg, p.o.) significantly inhibited reversed cutaneous anaphylaxis. Further, arctigenin (15 mg/kg, p.o.) significantly inhibited the Arthus reaction to sheep's red blood cells, decreasing the hemolysis titer, the hemagglutination titer, and the plaque-forming cell number for SRBCs. In addition, arctigenin significantly inhibited delayed type hypersensitivity at 15 mg/kg, p.o. and the formation of rosette-forming cells at 45 mg/kg, p.o. Contact dermatitis induced by picrylchloride and dinitrofluorobenzene was significantly (p < 0.05) inhibited by surface treatment with arctigenin (0.3 mg/ear). Furthermore, arctigenin dose-dependently inhibited pro-inflammatory enzymes, such as cyclooxygenase-1 and 2, 5-lipoxygenase, phospholipase A2, and phosphodiesterase. Our results show that arctigenin significantly inhibited B- and T-cell mediated allergic inflammation as well as pro-inflammatory enzymes.

  7. Y-configured metallic stent combined with 125I seed strands cavity brachytherapy for a patient with type IV Klatskin tumor

    PubMed Central

    Dechao, Jiao; Yanli, Wang; Zhen, Li

    2016-01-01

    We report a case in an inoperable patient with type IV Klatskin tumor treated by the use of a novel, two piece, Y-configured self-expandable metallic stent (SEMS) combined with two 125I seed strands via bilateral approach. The placement of the Y-shaped SEMS was successful and resulted in adequate biliary drainage. After 2 months of intraluminal brachytherapy (ILBT), both 125I seed strands and temporary drainage catheter were removed after patency of the expanded stents was confirmed by the cholangiogram. This technique was feasible and could be considered for the treatment of patients with Bismuth type IV Klatskin tumors. PMID:27648091

  8. Genome Sequencing of Xanthomonas vasicola Pathovar vasculorum Reveals Variation in Plasmids and Genes Encoding Lipopolysaccharide Synthesis, Type-IV Pilus and Type-III Secretion Effectors.

    PubMed

    Wasukira, Arthur; Coulter, Max; Al-Sowayeh, Noorah; Thwaites, Richard; Paszkiewicz, Konrad; Kubiriba, Jerome; Smith, Julian; Grant, Murray; Studholme, David J

    2014-03-18

    Xanthomonas vasicola pathovar vasculorum (Xvv) is the bacterial agent causing gumming disease in sugarcane. Here, we compare complete genome sequences for five isolates of Xvv originating from sugarcane and one from maize. This identified two distinct types of lipopolysaccharide synthesis gene clusters among Xvv isolates: one is similar to that of Xanthomonas axonopodis pathovar citri (Xac) and is probably the ancestral type, while the other is similar to those of the sugarcane-inhabiting species, Xanthomonas sacchari. Four of six Xvv isolates harboured sequences similar to the Xac plasmid, pXAC47, and showed a distinct Type-IV pilus (T4P) sequence type, whereas the T4P locus of the other two isolates resembled that of the closely related banana pathogen, Xanthomonas campestris pathovar musacearum (Xcm). The Xvv isolate from maize has lost a gene encoding a homologue of the virulence effector, xopAF, which was present in all five of the sugarcane isolates, while xopL contained a premature stop codon in four out of six isolates. These findings shed new light on evolutionary events since the divergence of Xvv and Xcm, as well as further elucidating the relationships between the two closely related pathogens.

  9. Genome Sequencing of Xanthomonas vasicola Pathovar vasculorum Reveals Variation in Plasmids and Genes Encoding Lipopolysaccharide Synthesis, Type-IV Pilus and Type-III Secretion Effectors

    PubMed Central

    Wasukira, Arthur; Coulter, Max; Al-Sowayeh, Noorah; Thwaites, Richard; Paszkiewicz, Konrad; Kubiriba, Jerome; Smith, Julian; Grant, Murray; Studholme, David J.

    2014-01-01

    Xanthomonas vasicola pathovar vasculorum (Xvv) is the bacterial agent causing gumming disease in sugarcane. Here, we compare complete genome sequences for five isolates of Xvv originating from sugarcane and one from maize. This identified two distinct types of lipopolysaccharide synthesis gene clusters among Xvv isolates: one is similar to that of Xanthomonas axonopodis pathovar citri (Xac) and is probably the ancestral type, while the other is similar to those of the sugarcane-inhabiting species, Xanthomonas sacchari. Four of six Xvv isolates harboured sequences similar to the Xac plasmid, pXAC47, and showed a distinct Type-IV pilus (T4P) sequence type, whereas the T4P locus of the other two isolates resembled that of the closely related banana pathogen, Xanthomonas campestris pathovar musacearum (Xcm). The Xvv isolate from maize has lost a gene encoding a homologue of the virulence effector, xopAF, which was present in all five of the sugarcane isolates, while xopL contained a premature stop codon in four out of six isolates. These findings shed new light on evolutionary events since the divergence of Xvv and Xcm, as well as further elucidating the relationships between the two closely related pathogens. PMID:25437615

  10. Displacement of the predominant dengue virus from type 2 to type 1 with a subsequent genotype shift from IV to I in Surabaya, Indonesia 2008-2010.

    PubMed

    Yamanaka, Atsushi; Mulyatno, Kris C; Susilowati, Helen; Hendrianto, Eryk; Ginting, Amor P; Sary, Dian D; Rantam, Fedik A; Soegijanto, Soegeng; Konishi, Eiji

    2011-01-01

    Indonesia has annually experienced approximately 100,000 reported cases of dengue fever (DF) and dengue hemorrhagic fever (DHF) in recent years. However, epidemiological surveys of dengue viruses (DENVs) have been limited in this country. In Surabaya, the second largest city, a single report indicated that dengue virus type 2 (DENV2) was the predominant circulating virus in 2003-2005. We conducted three surveys in Surabaya during: (i) April 2007, (ii) June 2008 to April 2009, and (iii) September 2009 to December 2010. A total of 231 isolates were obtained from dengue patients and examined by PCR typing. We found that the predominant DENV shifted from type 2 to type 1 between October and November 2008. Another survey using wild-caught mosquitoes in April 2009 confirmed that dengue type 1 virus (DENV1) was the predominant type in Surabaya. Phylogenetic analyses of the nucleotide sequences of the complete envelope gene of DENV1 indicated that all 22 selected isolates in the second survey belonged to genotype IV and all 17 selected isolates in the third survey belonged to genotype I, indicating a genotype shift between April and September 2009. Furthermore, in December 2010, isolates were grouped into a new clade of DENV1 genotype I, suggesting clade shift between September and December 2010. According to statistics reported by the Surabaya Health Office, the proportion of DHF cases among the total number of dengue cases increased about three times after the type shift in 2008. In addition, the subsequent genotype shift in 2009 was associated with the increased number of total dengue cases. This indicates the need for continuous surveillance of circulating viruses to predict the risk of DHF and DF.

  11. Displacement of the Predominant Dengue Virus from Type 2 to Type 1 with a Subsequent Genotype Shift from IV to I in Surabaya, Indonesia 2008–2010

    PubMed Central

    Yamanaka, Atsushi; Mulyatno, Kris C.; Susilowati, Helen; Hendrianto, Eryk; Ginting, Amor P.; Sary, Dian D.; Rantam, Fedik A.; Soegijanto, Soegeng; Konishi, Eiji

    2011-01-01

    Indonesia has annually experienced approximately 100,000 reported cases of dengue fever (DF) and dengue hemorrhagic fever (DHF) in recent years. However, epidemiological surveys of dengue viruses (DENVs) have been limited in this country. In Surabaya, the second largest city, a single report indicated that dengue virus type 2 (DENV2) was the predominant circulating virus in 2003–2005. We conducted three surveys in Surabaya during: (i) April 2007, (ii) June 2008 to April 2009, and (iii) September 2009 to December 2010. A total of 231 isolates were obtained from dengue patients and examined by PCR typing. We found that the predominant DENV shifted from type 2 to type 1 between October and November 2008. Another survey using wild-caught mosquitoes in April 2009 confirmed that dengue type 1 virus (DENV1) was the predominant type in Surabaya. Phylogenetic analyses of the nucleotide sequences of the complete envelope gene of DENV1 indicated that all 22 selected isolates in the second survey belonged to genotype IV and all 17 selected isolates in the third survey belonged to genotype I, indicating a genotype shift between April and September 2009. Furthermore, in December 2010, isolates were grouped into a new clade of DENV1 genotype I, suggesting clade shift between September and December 2010. According to statistics reported by the Surabaya Health Office, the proportion of DHF cases among the total number of dengue cases increased about three times after the type shift in 2008. In addition, the subsequent genotype shift in 2009 was associated with the increased number of total dengue cases. This indicates the need for continuous surveillance of circulating viruses to predict the risk of DHF and DF. PMID:22087290

  12. NMR studies demonstrate a unique AAB composition and chain register for a heterotrimeric type IV collagen model peptide containing a natural interruption site.

    PubMed

    Xiao, Jianxi; Sun, Xiuxia; Madhan, Balaraman; Brodsky, Barbara; Baum, Jean

    2015-10-02

    All non-fibrillar collagens contain interruptions in the (Gly-X-Y)n repeating sequence, such as the more than 20 interruptions found in chains of basement membrane type IV collagen. Two selectively doubly labeled peptides are designed to model a site in type IV collagen with a GVG interruption in the α1(IV) and a corresponding GISLK sequence within the α2(IV) chain. CD and NMR studies on a 2:1 mixture of these two peptides support the formation of a single-component heterotrimer that maintains the one-residue staggering in the triple-helix, has a unique chain register, and contains hydrogen bonds at the interruption site. Formation of hydrogen bonds at interruption sites may provide a driving force for self-assembly and chain register in type IV and other non-fibrillar collagens. This study illustrates the potential role of interruptions in the structure, dynamics, and folding of natural collagen heterotrimers and forms a basis for understanding their biological role.

  13. Regulation of Type IV Pili Contributes to Surface Behaviors of Historical and Epidemic Strains of Clostridium difficile

    PubMed Central

    Purcell, Erin B.; McKee, Robert W.; Bordeleau, Eric; Burrus, Vincent

    2015-01-01

    ABSTRACT The intestinal pathogen Clostridium difficile is an urgent public health threat that causes antibiotic-associated diarrhea and is a leading cause of fatal nosocomial infections in the United States. C. difficile rates of recurrence and mortality have increased in recent years due to the emergence of so-called “hypervirulent” epidemic strains. A great deal of the basic biology of C. difficile has not been characterized. Recent findings that flagellar motility, toxin synthesis, and type IV pilus (TFP) formation are regulated by cyclic diguanylate (c-di-GMP) reveal the importance of this second messenger for C. difficile gene regulation. However, the function(s) of TFP in C. difficile remains largely unknown. Here, we examine TFP-dependent phenotypes and the role of c-di-GMP in controlling TFP production in the historical 630 and epidemic R20291 strains of C. difficile. We demonstrate that TFP contribute to C. difficile biofilm formation in both strains, but with a more prominent role in R20291. Moreover, we report that R20291 is capable of TFP-dependent surface motility, which has not previously been described in C. difficile. The expression and regulation of the pilA1 pilin gene differs between R20291 and 630, which may underlie the observed differences in TFP-mediated phenotypes. The differences in pilA1 expression are attributable to greater promoter-driven transcription in R20291. In addition, R20291, but not 630, upregulates c-di-GMP levels during surface-associated growth, suggesting that the bacterium senses its substratum. The differential regulation of surface behaviors in historical and epidemic C. difficile strains may contribute to the different infection outcomes presented by these strains. IMPORTANCE How Clostridium difficile establishes and maintains colonization of the host bowel is poorly understood. Surface behaviors of C. difficile are likely relevant during infection, representing possible interactions between the bacterium and the

  14. Pea Broth Enhances the Biocontrol Efficacy of Lysobacter capsici AZ78 by Triggering Cell Motility Associated with Biogenesis of Type IV Pilus

    PubMed Central

    Tomada, Selena; Puopolo, Gerardo; Perazzolli, Michele; Musetti, Rita; Loi, Nazia; Pertot, Ilaria

    2016-01-01

    Bacterial cells can display different types of motility, due to the presence of external appendages such as flagella and type IV pili. To date, little information on the mechanisms involved in the motility of the Lysobacter species has been available. Recently, L. capsici AZ78, a biocontrol agent of phytopathogenic oomycetes, showed the ability to move on jellified pea broth. Pea broth medium improved also the biocontrol activity of L. capsici AZ78 against Plasmopara viticola under greenhouse conditions. Noteworthy, the quantity of pea residues remaining on grapevine leaves fostered cell motility in L. capsici AZ78. Based on these results, this unusual motility related to the composition of the growth medium was investigated in bacterial strains belonging to several Lysobacter species. The six L. capsici strains tested developed dendrite-like colonies when grown on jellified pea broth, while the development of dendrite-like colonies was not recorded in the media commonly used in motility assays. To determine the presence of genes responsible for biogenesis of the flagellum and type IV pili, the genome of L. capsici AZ78 was mined. Genes encoding structural components and regulatory factors of type IV pili were upregulated in L. capsici AZ78 cells grown on the above-mentioned medium, as compared with the other tested media. These results provide new insight into the motility mechanism of L. capsici members and the role of type IV pili and pea compounds on the epiphytic fitness and biocontrol features of L. capsici AZ78. PMID:27507963

  15. Immunohistochemical analysis of collagen types I, III, IV and alpha-actin in the urethra of sexually intact and ovariectomized beagles.

    PubMed

    Augsburger, Heinz R; Oswald, Marianne

    2007-09-01

    Urinary incontinence is a widespread problem in both postmenopausal women and ovariectomized dogs. The objective of this study was to investigate the influence of ovariectomy on the immunoreactivity and the distribution pattern of collagens I, III, IV and alpha-actin in the canine urethra. The immunohistochemical results were evaluated in five sexually intact and five ovariectomized beagles. The immunostaining of both collagens I and III delineated urethral connective tissue fibres and co-localized within in the fibres of both groups. The basement membranes of smooth muscle cells and sinusoids showed marked type IV collagen expression, whereas only faint immunoreactivity was present at the urothelial-stromal interface. No differences could be detected in the expression or distribution of the assessed collagen types and actin between ovariectomized and control animals. In conclusion, ovariectomy does not appear to have an effect on urethral collagens I, III, IV and smooth muscle actin in the dog, as ascertained by immunohistochemistry.

  16. Computational prediction of secretion systems and secretomes of Brucella: identification of novel type IV effectors and their interaction with the host.

    PubMed

    Sankarasubramanian, Jagadesan; Vishnu, Udayakumar S; Dinakaran, Vasudevan; Sridhar, Jayavel; Gunasekaran, Paramasamy; Rajendhran, Jeyaprakash

    2016-01-01

    Brucella spp. are facultative intracellular pathogens that cause brucellosis in various mammals including humans. Brucella survive inside the host cells by forming vacuoles and subverting host defence systems. This study was aimed to predict the secretion systems and the secretomes of Brucella spp. from 39 complete genome sequences available in the databases. Furthermore, an attempt was made to identify the type IV secretion effectors and their interactions with host proteins. We predicted the secretion systems of Brucella by the KEGG pathway and SecReT4. Brucella secretomes and type IV effectors (T4SEs) were predicted through genome-wide screening using JVirGel and S4TE, respectively. Protein-protein interactions of Brucella T4SEs with their hosts were analyzed by HPIDB 2.0. Genes coding for Sec and Tat pathways of secretion and type I (T1SS), type IV (T4SS) and type V (T5SS) secretion systems were identified and they are conserved in all the species of Brucella. In addition to the well-known VirB operon coding for the type IV secretion system (T4SS), we have identified the presence of additional genes showing homology with T4SS of other organisms. On the whole, 10.26 to 14.94% of total proteomes were found to be either secreted (secretome) or membrane associated (membrane proteome). Approximately, 1.7 to 3.0% of total proteomes were identified as type IV secretion effectors (T4SEs). Prediction of protein-protein interactions showed 29 and 36 host-pathogen specific interactions between Bos taurus (cattle)-B. abortus and Ovis aries (sheep)-B. melitensis, respectively. Functional characterization of the predicted T4SEs and their interactions with their respective hosts may reveal the secrets of host specificity of Brucella.

  17. Substitution of cysteine for glycine at residue 415 of one allele of the alpha 1(I) chain of type I procollagen in type III/IV osteogenesis imperfecta.

    PubMed Central

    Nicholls, A C; Oliver, J; Renouf, D V; Keston, M; Pope, F M

    1991-01-01

    We have examined the type I collagen in a patient with type III/IV osteogenesis imperfecta. Two forms of alpha 1(I) chain were produced, one normal and the other containing a cysteine residue within the triple helical domain of the molecule. Cysteine is not normally present in this domain of type I collagen. Peptide mapping experiments localised the mutation to peptide alpha 1(I)CB3 which spans residues 403 to 551 of the triple helix. Subsequent PCR amplification of cDNA covering this region followed by sequencing showed a G to T single base change in the GGC codon for glycine 415 generating TGC, the codon for cysteine. The effect of the mutation on the protein is to delay secretion from the cell, reduce the thermal stability of the molecule by 2 degrees C, and cause excessive post-translational modification of all chains in molecules containing one or more mutant alpha 1(I) chains. The clinical phenotype observed in this patient and the position of the mutation conform to the recent prediction of Starman et al that Gly----Cys mutations in the alpha 1(I) chain have a gradient of severity decreasing from the C-terminus to the N-terminus. Images PMID:1770532

  18. Detection and characterisation of an overmodified type III collagen by analysis of non-cutaneous connective tissues in a patient with Ehlers-Danlos syndrome IV.

    PubMed Central

    Nuytinck, L; Narcisi, P; Nicholls, A; Renard, J P; Pope, F M; De Paepe, A

    1992-01-01

    The clinical and biochemical observations in a patient with a mild form of Ehlers-Danlos syndrome (EDS) type IV are described. The patient's skin fibroblasts produced markedly diminished amounts of type III collagen. SDS-polyacrylamide gel electrophoresis of collagens produced by cells obtained from other, non-cutaneous tissues showed two forms of collagen alpha 1(III) chains, a normal and a slow migrating, mutant form. Further analysis confirmed that the type III collagen molecules containing mutant alpha chains which were overmodified had a lower thermal stability and were poorly secreted into the extracellular medium. The protein defect was mapped by in situ cyanogen bromide digestion and was located in alpha 1(III) CB9, the C-terminal peptide of the collagen triple helix. This study shows that non-cutaneous connective tissues can be a useful source for the study of type III collagen defects in patients with EDS type IV. Images PMID:1619632

  19. Density-dependent induction of 92-kd type IV collagenase activity in cultures of A431 human epidermoid carcinoma cells.

    PubMed Central

    Xie, B.; Bucana, C. D.; Fidler, I. J.

    1994-01-01

    We examined the in vitro regulation of the production of two type IV collagenases, MMP-2 and MMP-9, by A431 human epidermoid carcinoma cells. The A431 cells were cultured under sparse or confluent conditions. The addition of transforming growth factor-beta (TGF-beta) or phorbolester-TPA to sparse cultures induced low levels of MMP-9 secretion, whereas in confluent cultures only TGF-beta produced this effect. Neither treatment altered the level of constitutive secretion of MMP-2. Treatment of sparse, actively growing cultures but not confluent stationary cultures with both TGF-beta and TPA produced synergistic induction of MMP-9 but did not affect MMP-2. A431 cells were grown as discrete large monolayer colonies. Radiolabeling with [3H]leucine or [3H]thymidine followed by autoradiography revealed that all the A431 cells in the colonies were metabolically active and only those on the periphery were dividing. Only these dividing A431 cells stained positive by anti-MMP-9 antibodies. Our results demonstrate that the synergistic induction of MMP-9 secretion in A431 cells occurs subsequent to stimulation by external signals in only noncontact-inhibited dividing tumor cells. These regulatory mechanisms may account for the in vivo finding that many proteinases are localized at the invasion front of a neoplasm where tumor cells are dividing and accessible to various environmental signals. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:8178929

  20. Generation mechanism of the slowly drifting narrowband structure in the type IV solar radio bursts observed by AMATERAS

    SciTech Connect

    Katoh, Y.; Nishimura, Y.; Kumamoto, A.; Ono, T.; Iwai, K.; Misawa, H.; Tsuchiya, F.

    2014-05-20

    We investigate the type IV burst event observed by AMATERAS on 2011 June 7, and reveal that the main component of the burst was emitted from the plasmoid eruption identified in the EUV images of the Solar Dynamics Observatory (SDO)/AIA. We show that a slowly drifting narrowband structure (SDNS) appeared in the burst's spectra. Using statistical analysis, we reveal that the SDNS appeared for a duration of tens to hundreds of milliseconds and had a typical bandwidth of 3 MHz. To explain the mechanism generating the SDNS, we propose wave-wave coupling between Langmuir waves and whistler-mode chorus emissions generated in a post-flare loop, which were inferred from the similarities in the plasma environments of a post-flare loop and the equatorial region of Earth's inner magnetosphere. We assume that a chorus element with a rising tone is generated at the top of a post-flare loop. Using the magnetic field and plasma density models, we quantitatively estimate the expected duration of radio emissions generated from coupling between Langmuir waves and chorus emissions during their propagation in the post-flare loop, and we find that the observed duration and bandwidth properties of the SDNS are consistently explained by the proposed generation mechanism. While observations in the terrestrial magnetosphere show that the chorus emissions are a group of large-amplitude wave elements generated naturally and intermittently, the mechanism proposed in the present study can explain both the intermittency and the frequency drift in the observed spectra.

  1. Subtilisin-like protease-1 secreted through type IV secretion system contributes to high virulence of Streptococcus suis 2

    PubMed Central

    Yin, Supeng; Li, Ming; Rao, Xiancai; Yao, Xinyue; Zhong, Qiu; Wang, Min; Wang, Jing; Peng, Yizhi; Tang, Jiaqi; Hu, Fuquan; Zhao, Yan

    2016-01-01

    Streptococcus suis serotype 2 is an emerging zoonotic pathogen that triggered two outbreaks of streptococcal toxic shock syndrome (STSS) in China. Our previous research demonstrated that a type IV secretion system (T4SS) harbored in the 89K pathogenicity island contributes to the pathogenicity of S. suis 2. In the present study, a shotgun proteomics approach was employed to identify the effectors secreted by T4SS in S. suis 2, and surface-associated subtilisin-like protease-1 (SspA-1) was identified as a potential virulence effector. Western blot analysis and pull-down assay revealed that SspA-1 secretion depends on T4SS. Knockout mutations affecting sspA-1 attenuated S. suis 2 and impaired the pathogen’s ability to trigger inflammatory response in mice. And purified SspA-1 induced the secretion of IL-6, TNF-α, and IL-12p70 in THP-1 cells directly. SspA-1 is the first T4SS virulence effector reported in Gram-positive bacteria. Overall, these findings allow us to gain further insights into the pathogenesis of T4SS and STSS. PMID:27270879

  2. Infection-associated type IV secretion systems of Bartonella and their diverse roles in host cell interaction

    PubMed Central

    Dehio, Christoph

    2008-01-01

    Type IV secretion systems (T4SSs) are transporters of Gram-negative bacteria that mediate interbacterial DNA transfer, and translocation of virulence factors into eukaryotic host cells. The α-proteobacterial genus Bartonella comprises arthropod-borne pathogens that colonize endothelial cells and erythrocytes of their mammalian reservoir hosts, thereby causing long-lasting intraerythrocytic infections. The deadly human pathogen Bartonella bacilliformis holds an isolated position in the Bartonella phylogeny as a sole representative of an ancestral lineage. All other species evolved in a separate ‘modern’ lineage by radial speciation and represent highly host-adapted pathogens of limited virulence potential. Unlike B. bacilliformis, the species of the modern lineage encode at least one of the closely related T4SSs, VirB/VirD4 or Vbh. These VirB-like T4SSs represent major host adaptability factors that contributed to the remarkable evolutionary success of the modern lineage. At the molecular level, the VirB/VirD4 T4SS was shown to translocate several effector proteins into endothelial cells that subvert cellular functions critical for establishing chronic infection. A third T4SS, Trw, is present in a sub-branch of the modern lineage. Trw does not translocate any known effectors, but produces multiple variant pilus subunits critically involved in the invasion of erythrocytes. The T4SSs laterally acquired by the bartonellae have thus adopted highly diverse functions during infection, highlighting their versatility as pathogenicity factors. PMID:18489724

  3. Molecular characterization and polyclonal antibody generation against core component CagX protein of Helicobacter pylori type IV secretion system

    PubMed Central

    Gopal, Gopal Jee; Kumar, Awanish; Pal, Jagannath; Mukhopadhyay, Gauranga

    2014-01-01

    Gram-negative bacteria Helicobacter pylori cause gastric ulcer, duodenal cancer, and found in almost half of the world’s residents. The protein responsible for this disease is secreted through type IV secretion system (TFSS) of H. pylori. TFSS is encoded by 40-kb region of chromosomal DNA known as cag-pathogenicity island (PAI). TFSS comprises of three major components: cytoplasmic/inner membrane ATPase, transmembrane core-complex and outer membranous pilli, and associated subunits. Core complex consists of CagX, CagT, CagM, and Cag3(δ) proteins as per existing knowledge. In this study, we have characterized one of the important component of core-complex forming sub-unit protein, i.e., CagX. Complete ORF of CagX except signal peptide coding region was cloned and expressed in pET28a vector. Purification of CagX protein was performed, and polyclonal anti-sera against full-length recombinant CagX were raised in rabbit model. We obtained a very specific and high titer, CagX anti-sera that were utilized to characterize endogenous CagX. Surface localization of CagX was also seen by immunofluorescence microscopy. In short for the first time a full-length CagX was characterized, and we showed that CagX is the part of high molecular weight core complex, which is important for assembly and function of H. pylori TFSS. PMID:24637488

  4. Molecular and comparative analyses of type IV antifreeze proteins (AFPIVs) from two Antarctic fishes, Pleuragramma antarcticum and Notothenia coriiceps.

    PubMed

    Lee, Jong Kyu; Kim, Yeon Ju; Park, Kyoung Sun; Shin, Seung Chul; Kim, Hak Jun; Song, Young Hwan; Park, Hyun

    2011-08-01

    Antifreeze protein type IV (AFPIV) cDNAs and genomic DNAs from the Antarctic fishes Pleuragramma antarcticum (Pa) and Notothenia coriiceps (Nc) were cloned and sequenced, respectively. Each cDNA encoded 128 amino acids, with 94% similarity between the two and 83% similarity with AFPIV of the longhorn sculpin, Myoxocephalus octodecemspinosus. The genome structures of both genes consisted of four exons and three introns, and were highly conserved in terms of sequences and positions. In contrast, the third intron of PaAFPIV had additional nucleotides with inverted repeats at each end, which appeared to be a MITE-like transposable element. Comparative analysis revealed that fish AFPIVs were widely distributed across teleost fishes, well conserved in their intron positions, but more variable in intron sequences and sizes. However, the intron sequences of two Antarctic fishes were highly conserved, indicating recent radiation of notothenioids in the evolutionary lineage. The recombinant PaAFPIV and NcAFPIV were expressed in E. coli, and examined antifreeze activity. PaAFPIV and NcAFPIV gave ice crystals with star-shaped morphology, and thermal hysteresis (TH) values were 0.08°C at the concentration of 0.5mg/ml.

  5. P. aeruginosa PilT Structures with and without Nucleotide Reveal a Dynamic Type IV Pilus Retraction Motor

    SciTech Connect

    Misic, Ana M.; Satyshur, Kenneth A.; Forest, Katrina T.

    2010-10-18

    Type IV pili are bacterial extracellular filaments that can be retracted to create force and motility. Retraction is accomplished by the motor protein PilT. Crystal structures of Pseudomonas aeruginosa PilT with and without bound {beta},{gamma}-methyleneadenosine-5{prime}-triphosphate have been solved at 2.6 {angstrom} and 3.1 {angstrom} resolution, respectively, revealing an interlocking hexamer formed by the action of a crystallographic 2-fold symmetry operator on three subunits in the asymmetric unit and held together by extensive ionic interactions. The roles of two invariant carboxylates, Asp Box motif Glu163 and Walker B motif Glu204, have been assigned to Mg{sup 2+} binding and catalysis, respectively. The nucleotide ligands in each of the subunits in the asymmetric unit of the {beta},{gamma}-methyleneadenosine-5{prime}-triphosphate-bound PilT are not equally well ordered. Similarly, the three subunits in the asymmetric unit of both structures exhibit differing relative conformations of the two domains. The 12{sup o} and 20{sup o} domain rotations indicate motions that occur during the ATP-coupled mechanism of the disassembly of pili into membrane-localized pilin monomers. Integrating these observations, we propose a three-state 'Ready, Active, Release' model for the action of PilT.

  6. Stromal expression of 72 kda type IV collagenase (MMP-2) and TIMP-2 mRNAs in colorectal neoplasia.

    PubMed Central

    Poulsom, R.; Pignatelli, M.; Stetler-Stevenson, W. G.; Liotta, L. A.; Wright, P. A.; Jeffery, R. E.; Longcroft, J. M.; Rogers, L.; Stamp, G. W.

    1992-01-01

    We undertook an in situ hybridization study to localize the mRNAs for the 72 kda type IV collagenase (MMP-2) and its specific inhibitor (TIMP-2) in 12 colorectal carcinomas, 3 adenomas, and 4 uninvolved resection margins to see how their distributions correlated with that of the reported distribution of MMP-2 protein. Labeling for MMP-2 and TIMP-2 mRNAs was detectable in 10 of 12 carcinomas and in 2 of 3 adenomas. Unexpectedly, we found much stronger signals for MMP-2 and TIMP-2 mRNAs within the mesenchymal cells in the desmoplastic stroma, of endothelial and/or (myo)fibroblastic nature, rather than in tumor epithelial cells in which localization of MMP-2 was anticipated. Our data indicate that stromal cells may have the ability to synthesize a metalloproteinase that degrades basement membrane, and may together with the neoplastic epithelial cells participate actively in the tissue remodeling and disruption of the basement membrane integrity which is characteristic of invasive tumors. Images Figure 1 to 6 PMID:1323219

  7. Visualization of VirE2 protein translocation by the Agrobacterium type IV secretion system into host cells

    PubMed Central

    Sakalis, Philippe A; van Heusden, G Paul H; Hooykaas, Paul J J

    2014-01-01

    Type IV secretion systems (T4SS) can mediate the translocation of bacterial virulence proteins into host cells. The plant pathogen Agrobacterium tumefaciens uses a T4SS to deliver a VirD2-single stranded DNA complex as well as the virulence proteins VirD5, VirE2, VirE3, and VirF into host cells so that these become genetically transformed. Besides plant cells, yeast and fungi can efficiently be transformed by Agrobacterium. Translocation of virulence proteins by the T4SS has so far only been shown indirectly by genetic approaches. Here we report the direct visualization of VirE2 protein translocation by using bimolecular fluorescence complementation (BiFC) and Split GFP visualization strategies. To this end, we cocultivated Agrobacterium strains expressing VirE2 tagged with one part of a fluorescent protein with host cells expressing the complementary part, either fused to VirE2 (for BiFC) or not (Split GFP). Fluorescent filaments became visible in recipient cells 20–25 h after the start of the cocultivation indicative of VirE2 protein translocation. Evidence was obtained that filament formation was due to the association of VirE2 with the microtubuli. PMID:24376037

  8. Visualization of VirE2 protein translocation by the Agrobacterium type IV secretion system into host cells.

    PubMed

    Sakalis, Philippe A; van Heusden, G Paul H; Hooykaas, Paul J J

    2014-02-01

    Type IV secretion systems (T4SS) can mediate the translocation of bacterial virulence proteins into host cells. The plant pathogen Agrobacterium tumefaciens uses a T4SS to deliver a VirD2-single stranded DNA complex as well as the virulence proteins VirD5, VirE2, VirE3, and VirF into host cells so that these become genetically transformed. Besides plant cells, yeast and fungi can efficiently be transformed by Agrobacterium. Translocation of virulence proteins by the T4SS has so far only been shown indirectly by genetic approaches. Here we report the direct visualization of VirE2 protein translocation by using bimolecular fluorescence complementation (BiFC) and Split GFP visualization strategies. To this end, we cocultivated Agrobacterium strains expressing VirE2 tagged with one part of a fluorescent protein with host cells expressing the complementary part, either fused to VirE2 (for BiFC) or not (Split GFP). Fluorescent filaments became visible in recipient cells 20-25 h after the start of the cocultivation indicative of VirE2 protein translocation. Evidence was obtained that filament formation was due to the association of VirE2 with the microtubuli.

  9. Structural characterization of the mesangial cell type IV collagenase and enhanced expression in a model of immune complex-mediated glomerulonephritis.

    PubMed Central

    Lovett, D. H.; Johnson, R. J.; Marti, H. P.; Martin, J.; Davies, M.; Couser, W. G.

    1992-01-01

    Secretion of glomerular cell-derived matrix metalloproteinases (MMPs) and their specific inhibitors, TIMP-1,2, may play an important role in the turnover of the glomerular extracellular matrix under basal and pathologic conditions. A 66-68 kd MMP secreted by cultured mesangial cells (MC) with activity against Type IV collagen and gelatin was purified and shown by amino-acid sequence analysis to be identical with a Type IV collagenase/gelatinase secreted by certain transformed tumor cell lines. The expression of the mesangial MMP in vivo was limited within the kidney to a small subset of the intrinsic glomerular mesangial cell population. After induction of acute anti-Thy 1.1 glomerulonephritis, there was a large increment in the number of Type IV collagenase-secreting MC, temporally coincident with the development of mesangial hypercellularity. The expression of the MMP inhibitor protein, TIMP-1, was not changed over this period. Ultrastructural studies localized the mesangial MMP to areas of evolving mesangiolysis and at sites of glomerular basement membrane disruption. Enhanced expression of the mesangial cell-derived Type IV collagenase may contribute to the evolution of glomerular injury in this model of immune complex-mediated glomerulonephritis or may be involved in the extensive matrix remodeling process that accompanies this form of glomerular injury. Images Figure 2 Figure 3 Figure 5 Figure 4 Figure 6 Figure 7 Figure 8 and Figure 9 Figure 10 Figure 11 Figure 12 PMID:1321565

  10. Relationship among follicular apoptosis, integrin beta1 and collagen type IV during early ovarian regression in the teleost Prochilodus argenteus after induced spawning.

    PubMed

    Santos, H B; Sato, Y; Moro, L; Bazzoli, N; Rizzo, E

    2008-04-01

    Early ovarian regression was analyzed in the neotropical freshwater teleost, curimatã-pacu (Prochilodus argenteus), in order to evaluate follicular apoptosis, basement membrane morphology, and integrin beta1 and collagen type IV immunostainning in postovulatory follicles. Mature females were induced to spawn by using carp pituitary extract for study of ovarian regression up to 5 days post-spawning. Morphometric analyses showed that the postovulatory follicle area decreased progressively after spawning and was coupled to the gonadosomatic index (r=0.92). During ovarian regression, follicular cells detached from the neighboring cells and basement membrane and then died by apoptosis. The follicular basement membrane became thicker and diffuse and was breached during regression of the postovulatory follicles. Follicular apoptosis was detected by TUNEL, histology, and electron microscopy. The ladder pattern of apoptotic DNA was revealed by agarose gel electrophoresis. The apoptotic index for the follicular cells increased until 3 days post-spawning and decreased thereafter. Immunohistochemistry reactions detected caspase 3, integrin beta1, and collagen type IV in the follicular layer of the postovulatory follicles. Labeling for integrin beta1 and collagen type IV decreased significantly, whereas a peak in cell death occurred 3 days post-spawning. At 4-5 days post-spawning, the connective theca was more thickened and vascularized. Simultaneously, granulocytes migrated toward the follicular lumen. Thus, follicular apoptosis contributes to early ovarian regression in P. argenteus. Additionally, our findings suggest integrin beta1 and collagen type IV as possible survival factors for follicular cells in teleost ovary.

  11. Parallel Evolution of a Type IV Secretion System in Radiating Lineages of the Host-Restricted Bacterial Pathogen Bartonella

    PubMed Central

    Engel, Philipp; Salzburger, Walter; Liesch, Marius; Chang, Chao-Chin; Maruyama, Soichi; Lanz, Christa; Calteau, Alexandra; Lajus, Aurélie; Médigue, Claudine; Schuster, Stephan C.; Dehio, Christoph

    2011-01-01

    Adaptive radiation is the rapid origination of multiple species from a single ancestor as the result of concurrent adaptation to disparate environments. This fundamental evolutionary process is considered to be responsible for the genesis of a great portion of the diversity of life. Bacteria have evolved enormous biological diversity by exploiting an exceptional range of environments, yet diversification of bacteria via adaptive radiation has been documented in a few cases only and the underlying molecular mechanisms are largely unknown. Here we show a compelling example of adaptive radiation in pathogenic bacteria and reveal their genetic basis. Our evolutionary genomic analyses of the α-proteobacterial genus Bartonella uncover two parallel adaptive radiations within these host-restricted mammalian pathogens. We identify a horizontally-acquired protein secretion system, which has evolved to target specific bacterial effector proteins into host cells as the evolutionary key innovation triggering these parallel adaptive radiations. We show that the functional versatility and adaptive potential of the VirB type IV secretion system (T4SS), and thereby translocated Bartonella effector proteins (Beps), evolved in parallel in the two lineages prior to their radiations. Independent chromosomal fixation of the virB operon and consecutive rounds of lineage-specific bep gene duplications followed by their functional diversification characterize these parallel evolutionary trajectories. Whereas most Beps maintained their ancestral domain constitution, strikingly, a novel type of effector protein emerged convergently in both lineages. This resulted in similar arrays of host cell-targeted effector proteins in the two lineages of Bartonella as the basis of their independent radiation. The parallel molecular evolution of the VirB/Bep system displays a striking example of a key innovation involved in independent adaptive processes and the emergence of bacterial pathogens

  12. Parallel evolution of a type IV secretion system in radiating lineages of the host-restricted bacterial pathogen Bartonella.

    PubMed

    Engel, Philipp; Salzburger, Walter; Liesch, Marius; Chang, Chao-Chin; Maruyama, Soichi; Lanz, Christa; Calteau, Alexandra; Lajus, Aurélie; Médigue, Claudine; Schuster, Stephan C; Dehio, Christoph

    2011-02-10

    Adaptive radiation is the rapid origination of multiple species from a single ancestor as the result of concurrent adaptation to disparate environments. This fundamental evolutionary process is considered to be responsible for the genesis of a great portion of the diversity of life. Bacteria have evolved enormous biological diversity by exploiting an exceptional range of environments, yet diversification of bacteria via adaptive radiation has been documented in a few cases only and the underlying molecular mechanisms are largely unknown. Here we show a compelling example of adaptive radiation in pathogenic bacteria and reveal their genetic basis. Our evolutionary genomic analyses of the α-proteobacterial genus Bartonella uncover two parallel adaptive radiations within these host-restricted mammalian pathogens. We identify a horizontally-acquired protein secretion system, which has evolved to target specific bacterial effector proteins into host cells as the evolutionary key innovation triggering these parallel adaptive radiations. We show that the functional versatility and adaptive potential of the VirB type IV secretion system (T4SS), and thereby translocated Bartonella effector proteins (Beps), evolved in parallel in the two lineages prior to their radiations. Independent chromosomal fixation of the virB operon and consecutive rounds of lineage-specific bep gene duplications followed by their functional diversification characterize these parallel evolutionary trajectories. Whereas most Beps maintained their ancestral domain constitution, strikingly, a novel type of effector protein emerged convergently in both lineages. This resulted in similar arrays of host cell-targeted effector proteins in the two lineages of Bartonella as the basis of their independent radiation. The parallel molecular evolution of the VirB/Bep system displays a striking example of a key innovation involved in independent adaptive processes and the emergence of bacterial pathogens

  13. Type IV collagen degradation in the myocardial basement membrane after unloading of the failing heart by a left ventricular assist device.

    PubMed

    Bruggink, Annette H; van Oosterhout, Matthijs F M; de Jonge, Nicolaas; Cleutjens, Jack P M; van Wichen, Dick F; van Kuik, Joyce; Tilanus, Marcel G J; Gmelig-Meyling, Frits H J; van den Tweel, Jan G; de Weger, Roel A

    2007-11-01

    After left ventricular assist device (LVAD) support in patients with end-stage cardiomyopathy, cardiomyocytes decrease in size. We hypothesized that during this process, known as reverse remodeling, the basement membrane (BM), which is closely connected to, and forms the interface between the cardiomyocytes and the extracellular matrix, will be severely affected. Therefore, the changes in the myocardial BM in patients with end-stage heart failure before and after LVAD support were studied. The role of MMP-2 in this process was also investigated. Transmission electron microscopy showed that the BM thickness decreased post-LVAD compared to pre-LVAD. Immunohistochemistry indicated a reduced immunoreactivity for type IV collagen in the BM after LVAD support. Quantitative PCR showed a similar mRNA expression for type IV collagen pre- and post-LVAD. MMP-2 mRNA almost doubled post-LVAD (P<0.01). In addition, active MMP-2 protein as identified by gelatin zymography and confirmed by Western blot analysis was detected after LVAD support and in controls, but not before LVAD support. Active MMP was localized in the BM of the cardiomyocyte, as detected by type IV collagen in situ zymography. Furthermore, in situ hybridization/immunohistochemical double staining showed that MMP-2 mRNA was expressed in cardiomyocytes, macrophages, T-cells and endothelial cells. Taken together, these findings show reduced type IV collagen content in the BM of cardiomyocytes after LVAD support. This reduction is at least in part the result of increased MMP-2 activity and not due to reduced synthesis of type IV collagen.

  14. Selective type IV phosphodiesterase inhibitors as antiasthmatic agents. The syntheses and biological activities of 3-(cyclopentyloxy)-4-methoxybenzamides and analogues.

    PubMed

    Ashton, M J; Cook, D C; Fenton, G; Karlsson, J A; Palfreyman, M N; Raeburn, D; Ratcliffe, A J; Souness, J E; Thurairatnam, S; Vicker, N

    1994-05-27

    The syntheses and biological activities of a number of benzamide derivatives, designed from rolipram, which are selective inhibitors of cyclic AMP-specific phosphodiesterase (PDE IV), are described. The effects of changes to the alkoxy groups, amide linkage, and benzamide N-phenyl ring on the inhibition of the cytosolic PDE IV from pig aorta have been investigated. As a result, some highly potent and selective PDE IV inhibitors have been identified. The most potent compounds have been further evaluated for their inhibitory potencies against PDE IV obtained from and superoxide O2- generation from guinea pig eosinophils in vitro. Selected compounds have also been examined for their activities in inhibiting histamine-induced bronchospasm in anaesthetized guinea pigs. 3-(Cyclopentyloxy)-N-(3,5-dichloro-4-pyridyl)-4-methoxybenzamide (15j) showed exceptional potency in all tests and may have therapeutic potential in the treatment of asthma.

  15. Thermal stability of the helical structure of type IV collagen within basement membranes in situ: determination with a conformation-dependent monoclonal antibody

    PubMed Central

    1984-01-01

    To examine the thermal stability of the helical structure of type IV collagen within basement membranes in situ, we have employed indirect immunofluorescence histochemistry performed at progressively higher temperatures using a conformation-dependent antibody, IV-IA8. We previously observed by competition enzyme-linked immunosorbent assay that, in neutral solution, the helical epitope to which this antibody binds undergoes thermal denaturation over the range of 37-40 degrees C. In the present study, we have reacted unfixed cryostat tissue sections with this antibody at successively higher temperatures. We have operationally defined denaturation as the point at which type IV- specific fluorescence is no longer detectable. Under these conditions, the in situ denaturation temperature of this epitope in most basement membranes is 50-55 degrees C. In capillaries and some other small blood vessels the fluorescent signal is still clearly detectable at 60 degrees C, the highest temperature at which we can confidently use this technique. We conclude that the stability of the helical structure of type IV collagen within a basement membrane is considerably greater than it is in solution, and that conformation-dependent monoclonal antibodies can be useful probes for investigations of molecular structure in situ. PMID:6207181

  16. L-arginine mediated renaturation enhances yield of human, α6 type IV collagen non-collagenous domain from bacterial inclusion bodies

    PubMed Central

    Gunda, Venugopal; Boosani, Chandra Shekhar; Verma, Raj Kumar; Guda, Chittibabu; Akul Sudhakar, Yakkanti

    2012-01-01

    The anti-angiogenic, carboxy terminal non-collagenous domain (NC1) derived from human Collagen type IV alpha 6 chain, [α6(IV)NC1] or hexastatin, was earlier obtained using different recombinant methods of expression in bacterial systems. However, the effect of L-arginine mediated renaturation in enhancing the relative yields of this protein from bacterial inclusion bodies has not been evaluated. In the present study, direct stirring and on-column renaturation methods using L-arginine and different size exclusion chromatography matrices were applied for enhancing the solubility in purifying the recombinant α6(IV)NC1 from bacterial inclusion bodies. This methodology enabled purification of higher quantities of soluble protein from inclusion bodies, which inhibited endothelial cell proliferation, migration and tube formation. Thus, the scope for L-arginine mediated renaturation in obtaining higher yields of soluble, biologically active NC1 domain from bacterial inclusion bodies was evaluated. PMID:22512648

  17. L-arginine mediated renaturation enhances yield of human, α6 Type IV collagen non-collagenous domain from bacterial inclusion bodies.

    PubMed

    Gunda, Venugopal; Boosani, Chandra Shekhar; Verma, Raj Kumar; Guda, Chittibabu; Sudhakar, Yakkanti Akul

    2012-10-01

    The anti-angiogenic, carboxy terminal non-collagenous domain (NC1) derived from human Collagen type IV alpha 6 chain, [α6(IV)NC1] or hexastatin, was earlier obtained using different recombinant methods of expression in bacterial systems. However, the effect of L-arginine mediated renaturation in enhancing the relative yields of this protein from bacterial inclusion bodies has not been evaluated. In the present study, direct stirring and on-column renaturation methods using L-arginine and different size exclusion chromatography matrices were applied for enhancing the solubility in purifying the recombinant α6(IV)NC1 from bacterial inclusion bodies. This methodology enabled purification of higher quantities of soluble protein from inclusion bodies, which inhibited endothelial cell proliferation, migration and tube formation. Thus, the scope for L-arginine mediated renaturation in obtaining higher yields of soluble, biologically active NC1 domain from bacterial inclusion bodies was evaluated.

  18. Malleolar fractures and their ligamentous injury equivalents have similar outcomes in supination-external rotation type IV fractures of the ankle treated by anatomical internal fixation.

    PubMed

    Berkes, M B; Little, M T M; Lazaro, L E; Sculco, P K; Cymerman, R M; Daigl, M; Helfet, D L; Lorich, D G

    2012-11-01

    It has previously been suggested that among unstable ankle fractures, the presence of a malleolar fracture is associated with a worse outcome than a corresponding ligamentous injury. However, previous studies have included heterogeneous groups of injury. The purpose of this study was to determine whether any specific pattern of bony and/or ligamentous injury among a series of supination-external rotation type IV (SER IV) ankle fractures treated with anatomical fixation was associated with a worse outcome. We analysed a prospective cohort of 108 SER IV ankle fractures with a follow-up of one year. Pre-operative radiographs and MRIs were undertaken to characterise precisely the pattern of injury. Operative treatment included fixation of all malleolar fractures. Post-operative CT was used to assess reduction. The primary and secondary outcome measures were the Foot and Ankle Outcome Score (FAOS) and the range of movement of the ankle. There were no clinically relevant differences between the four possible SER IV fracture pattern groups with regard to the FAOS or range of movement. In this population of strictly defined SER IV ankle injuries, the presence of a malleolar fracture was not associated with a significantly worse clinical outcome than its ligamentous injury counterpart. Other factors inherent to the injury and treatment may play a more important role in predicting outcome.

  19. Type IV Secretion and Signal Transduction of Helicobacter pylori CagA through Interactions with Host Cell Receptors.

    PubMed

    Backert, Steffen; Tegtmeyer, Nicole

    2017-03-24

    Helicobacter pylori is a highly successful human bacterium, which is exceptionally equipped to persistently inhabit the human stomach. Colonization by this pathogen is associated with gastric disorders ranging from chronic gastritis and peptic ulcers to cancer. Highly virulent H. pylori strains express the well-established adhesins BabA/B, SabA, AlpA/B, OipA, and HopQ, and a type IV secretion system (T4SS) encoded by the cag pathogenicity island (PAI). The adhesins ascertain intimate bacterial contact to gastric epithelial cells, while the T4SS represents an extracellular pilus-like structure for the translocation of the effector protein CagA. Numerous T4SS components including CagI, CagL, CagY, and CagA have been shown to target the integrin-β₁ receptor followed by translocation of CagA across the host cell membrane. The interaction of CagA with membrane-anchored phosphatidylserine and CagA-containing outer membrane vesicles may also play a role in the delivery process. Translocated CagA undergoes tyrosine phosphorylation in C-terminal EPIYA-repeat motifs by oncogenic Src and Abl kinases. CagA then interacts with an array of host signaling proteins followed by their activation or inactivation in phosphorylation-dependent and phosphorylation-independent fashions. We now count about 25 host cell binding partners of intracellular CagA, which represent the highest quantity of all currently known virulence-associated effector proteins in the microbial world. Here we review the research progress in characterizing interactions of CagA with multiple host cell receptors in the gastric epithelium, including integrin-β₁, EGFR, c-Met, CD44, E-cadherin, and gp130. The contribution of these interactions to H. pylori colonization, signal transduction, and gastric pathogenesis is discussed.

  20. Camel milk attenuates the biochemical and morphological features of diabetic nephropathy: inhibition of Smad1 and collagen type IV synthesis.

    PubMed

    Korish, Aida A; Abdel Gader, Abdel Galil; Korashy, Hesham M; Al-Drees, Abdul Majeed; Alhaider, Abdulqader A; Arafah, Maha M

    2015-03-05

    Diabetic nephropathy (DN) is a common microvascular complication of diabetes mellitus (DM) that worsens its morbidity and mortality. There is evidence that camel milk (CM) improves the glycemic control in DM but its effect on the renal complications especially the DN remains unclear. Thus the current study aimed to characterize the effects of CM treatment on streptozotocin (STZ)-induced DN. Using STZ-induced diabetes, we investigated the effect of CM treatment on kidney function, proteinuria, renal Smad1, collagen type IV (Col4), blood glucose, insulin resistance (IR), lipid peroxidation, the antioxidant superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH). In addition renal morphology was also examined. The current results showed that rats with untreated diabetes exhibited marked hyperglycemia, IR, high serum urea and creatinine levels, excessive proteinuria, increased renal Smad1 and Col4, glomerular expansion, and extracellular matrix deposition. There was also increased lipid peroxidation products, decreased antioxidant enzyme activity and GSH levels. Camel milk treatment decreased blood glucose, IR, and lipid peroxidation. Superoxide dismutase and CAT expression, CAT activity, and GSH levels were increased. The renoprotective effects of CM were demonstrated by the decreased serum urea and creatinine, proteinuria, Smad1, Col4, and preserved normal tubulo-glomerular morphology. In conclusion, beside its hypoglycemic action, CM attenuates the early changes of DN, decreased renal Smad1 and Col4. This could be attributed to a primary action on the glomerular mesangial cells, or secondarily to the hypoglycemic and antioxidant effects of CM. The protective effects of CM against DN support its use as an adjuvant anti-diabetes therapy.

  1. Type IV pilin is glycosylated in Pseudomonas syringae pv. tabaci 6605 and is required for surface motility and virulence.

    PubMed

    Nguyen, Linh Chi; Taguchi, Fumiko; Tran, Quang Minh; Naito, Kana; Yamamoto, Masanobu; Ohnishi-Kameyama, Mayumi; Ono, Hiroshi; Yoshida, Mitsuru; Chiku, Kazuhiro; Ishii, Tadashi; Inagaki, Yoshishige; Toyoda, Kazuhiro; Shiraishi, Tomonori; Ichinose, Yuki

    2012-09-01

    Type IV pilin (PilA) is a major constituent of pilus and is required for bacterial biofilm formation, surface motility and virulence. It is known that mature PilA is produced by cleavage of the short leader sequence of the pilin precursor, followed by methylation of N-terminal phenylalanine. The molecular mass of the PilA mature protein from the tobacco bacterial pathogen Pseudomonas syringae pv. tabaci 6605 (Pta 6605) has been predicted to be 12 329 Da from its deduced amino acid sequence. Previously, we have detected PilA as an approximately 13-kDa protein by immunoblot analysis with anti-PilA-specific antibody. In addition, we found the putative oligosaccharide-transferase gene tfpO downstream of pilA. These findings suggest that PilA in Pta 6605 is glycosylated. The defective mutant of tfpO (ΔtfpO) shows reductions in pilin molecular mass, surface motility and virulence towards host tobacco plants. Thus, pilin glycan plays important roles in bacterial motility and virulence. The genetic region around pilA was compared among P. syringae pathovars. The tfpO gene exists in some strains of pathovars tabaci, syringae, lachrymans, mori, actinidiae, maculicola and P. savastanoi pv. savastanoi. However, some strains of pathovars tabaci, syringae, glycinea, tomato, aesculi and oryzae do not possess tfpO, and the existence of tfpO is independent of the classification of pathovars/strains in P. syringae. Interestingly, the PilA amino acid sequences in tfpO-possessing strains show higher homology with each other than with tfpO-nonpossessing strains. These results suggest that tfpO and pilA might co-evolve in certain specific bacterial strains.

  2. Collagen Type IV and Laminin Expressions during Cartilage Repair and in Late Clinically Failed Repair Tissues from Human Subjects

    PubMed Central

    Foldager, Casper Bindzus; Toh, Wei Seong; Christensen, Bjørn Borsøe; Lind, Martin; Gomoll, Andreas H.; Spector, Myron

    2016-01-01

    Objective To identify the collagen type IV (Col4) isoform in articular cartilage and to evaluate the expressions of Col4 and laminin in the pericellular matrix (PCM) in damaged cartilage and during cartilage repair. Design The Col4 isoform was determined in chondrocytes isolated from 6 patients cultured up to 6 days and in 21% O2 or 1% O2, and the gene expression of Col4 α-chains was investigated. The distribution of Col4 and laminin in traumatically damaged cartilage (n = 7) and clinically failed cartilage repair (microfracture, TruFit, autologous chondrocyte implantation; n = 11) were investigated using immunohistochemistry. Normal human cartilage was used as control (n = 8). The distribution during clinical cartilage repair procedures was investigated in a minipig model with 6-month follow-up (untreated chondral, untreated osteochondral, microfracture, autologous chondrocyte implantation; n = 10). Results The Col4 isoform in articular cartilage was characterized as α1α1α2, which is an isoform containing antiangiogenic domains in the NC1-terminals (arresten and canstatin). In normal cartilage, laminin and Col4 was exclusively found in the PCM. High amounts (>50%) of Col4 in the PCM significantly decreased in damaged cartilage (P = 0.004) and clinically failed repair tissue (P < 0.001). Laminin was only found with high expression (>50%) in 4/8 of the normal samples, which was not statistically significantly different from damaged cartilage (P = 0.15) or failed cartilage repair (P = 0.054). Conclusions Col4 in cartilage contain antiangiogenic domains and may play a role in the hypoxic environment in articular cartilage. Col4 and laminin was not found in the PCM of damaged and clinically failed repair. PMID:26958317

  3. Differential Contribution of Transmembrane Domains IV, V, VI, and VII to Human Angiotensin II Type 1 Receptor Homomer Formation.

    PubMed

    Young, Brent M; Nguyen, Elaine; Chedrawe, Matthew A J; Rainey, Jan K; Dupré, Denis J

    2017-02-24

    G protein-coupled receptors (GPCRs) play an important role in drug therapy and represent one of the largest families of drug targets. The angiotensin II type 1 receptor (AT1R) is notable as it has a central role in the treatment of cardiovascular disease. Blockade of AT1R signaling has been shown to alleviate hypertension and improve outcomes in patients with heart failure. Despite this, it has become apparent that our initial understanding of AT1R signaling is oversimplified. There is considerable evidence to suggest that AT1R signaling is highly modified in the presence of receptor-receptor interactions, but there is very little structural data available to explain this phenomenon even with the recent elucidation of the AT1R crystal structure. The current study investigates the involvement of transmembrane domains in AT1R homomer assembly with the goal of identifying hydrophobic interfaces that contribute to receptor-receptor affinity. A recently published crystal structure of the AT1R was used to guide site-directed mutagenesis of outward-facing hydrophobic residues within the transmembrane region of the AT1R. Bioluminescence resonance energy transfer was employed to analyze how receptor mutation affects the assembly of AT1R homomers with a specific focus on hydrophobic residues. Mutations within transmembrane domains IV, V, VI, and VII had no effect on angiotensin-mediated β-arrestin1 recruitment; however, they exhibited differential effects on the assembly of AT1R into oligomeric complexes. Our results demonstrate the importance of hydrophobic amino acids at the AT1R transmembrane interface and provide the first glimpse of the requirements for AT1R complex assembly.

  4. A bipartite signal mediates the transfer of type IV secretion substrates of Bartonella henselae into human cells

    PubMed Central

    Schulein, Ralf; Guye, Patrick; Rhomberg, Thomas A.; Schmid, Michael C.; Schröder, Gunnar; Vergunst, Annette C.; Carena, Ilaria; Dehio, Christoph

    2005-01-01

    Bacterial type IV secretion (T4S) systems mediate the transfer of macromolecular substrates into various target cells, e.g., the conjugative transfer of DNA into bacteria or the transfer of virulence proteins into eukaryotic host cells. The T4S apparatus VirB of the vascular tumor-inducing pathogen Bartonella henselae causes subversion of human endothelial cell (HEC) function. Here we report the identification of multiple protein substrates of VirB, which, upon translocation into HEC, mediate all known VirB-dependent cellular changes. These Bartonella-translocated effector proteins (Beps) A-G are encoded together with the VirB system and the T4S coupling protein VirD4 on a Bartonella-specific pathogenicity island. The Beps display a modular architecture, suggesting an evolution by extensive domain duplication and reshuffling. The C terminus of each Bep harbors at least one copy of the Bep-intracellular delivery domain and a short positively charged tail sequence. This biparte C terminus constitutes a transfer signal that is sufficient to mediate VirB/VirD4-dependent intracellular delivery of reporter protein fusions. The Bep-intracellular delivery domain is also present in conjugative relaxases of bacterial conjugation systems. We exemplarily show that the C terminus of such a conjugative relaxase mediates protein transfer through the Bartonella henselae VirB/VirD4 system into HEC. Conjugative relaxases may thus represent the evolutionary origin of the here defined T4S signal for protein transfer into human cells. PMID:15642951

  5. A bipartite signal mediates the transfer of type IV secretion substrates of Bartonella henselae into human cells.

    PubMed

    Schulein, Ralf; Guye, Patrick; Rhomberg, Thomas A; Schmid, Michael C; Schröder, Gunnar; Vergunst, Annette C; Carena, Ilaria; Dehio, Christoph

    2005-01-18

    Bacterial type IV secretion (T4S) systems mediate the transfer of macromolecular substrates into various target cells, e.g., the conjugative transfer of DNA into bacteria or the transfer of virulence proteins into eukaryotic host cells. The T4S apparatus VirB of the vascular tumor-inducing pathogen Bartonella henselae causes subversion of human endothelial cell (HEC) function. Here we report the identification of multiple protein substrates of VirB, which, upon translocation into HEC, mediate all known VirB-dependent cellular changes. These Bartonella-translocated effector proteins (Beps) A-G are encoded together with the VirB system and the T4S coupling protein VirD4 on a Bartonella-specific pathogenicity island. The Beps display a modular architecture, suggesting an evolution by extensive domain duplication and reshuffling. The C terminus of each Bep harbors at least one copy of the Bep-intracellular delivery domain and a short positively charged tail sequence. This biparte C terminus constitutes a transfer signal that is sufficient to mediate VirB/VirD4-dependent intracellular delivery of reporter protein fusions. The Bep-intracellular delivery domain is also present in conjugative relaxases of bacterial conjugation systems. We exemplarily show that the C terminus of such a conjugative relaxase mediates protein transfer through the Bartonella henselae VirB/VirD4 system into HEC. Conjugative relaxases may thus represent the evolutionary origin of the here defined T4S signal for protein transfer into human cells.

  6. Type IV pilins regulate their own expression via direct intramembrane interactions with the sensor kinase PilS

    PubMed Central

    Kilmury, Sara L. N.

    2016-01-01

    Type IV pili are important virulence factors for many pathogens, including Pseudomonas aeruginosa. Transcription of the major pilin gene—pilA—is controlled by the PilS-PilR two-component system in response to unknown signals. The absence of a periplasmic sensing domain suggested that PilS may sense an intramembrane signal, possibly PilA. We suggest that direct interactions between PilA and PilS in the inner membrane reduce pilA transcription when PilA levels are high. Overexpression in trans of PilA proteins with diverse and/or truncated C termini decreased native pilA transcription, suggesting that the highly conserved N terminus of PilA was the regulatory signal. Point mutations in PilA or PilS that disrupted their interaction prevented autoregulation of pilA transcription. A subset of PilA point mutants retained the ability to interact with PilS but could no longer decrease pilA transcription, suggesting that interaction between the pilin and sensor kinase is necessary but not sufficient for pilA autoregulation. Furthermore, PilS’s phosphatase motif was required for the autoregulation of pilA transcription, suggesting that under conditions where PilA is abundant, the PilA–PilS interaction promotes PilR dephosphorylation and thus down-regulation of further pilA transcription. These data reveal a clever bacterial inventory control strategy in which the major subunit of an important P. aeruginosa virulence factor controls its own expression. PMID:27162347

  7. Identification of ElpA, a Coxiella burnetii pathotype-specific Dot/Icm type IV secretion system substrate.

    PubMed

    Graham, Joseph G; Winchell, Caylin G; Sharma, Uma M; Voth, Daniel E

    2015-03-01

    Coxiella burnetii causes human Q fever, a zoonotic disease that presents with acute flu-like symptoms and can result in chronic life-threatening endocarditis. In human alveolar macrophages, C. burnetii uses a Dot/Icm type IV secretion system (T4SS) to generate a phagolysosome-like parasitophorous vacuole (PV) in which to replicate. The T4SS translocates effector proteins, or substrates, into the host cytosol, where they mediate critical cellular events, including interaction with autophagosomes, PV formation, and prevention of apoptosis. Over 100 C. burnetii Dot/Icm substrates have been identified, but the function of most remains undefined. Here, we identified a novel Dot/Icm substrate-encoding open reading frame (CbuD1884) present in all C. burnetii isolates except the Nine Mile reference isolate, where the gene is disrupted by a frameshift mutation, resulting in a pseudogene. The CbuD1884 protein contains two transmembrane helices (TMHs) and a coiled-coil domain predicted to mediate protein-protein interactions. The C-terminal region of the protein contains a predicted Dot/Icm translocation signal and was secreted by the T4SS, while the N-terminal portion of the protein was not secreted. When ectopically expressed in eukaryotic cells, the TMH-containing N-terminal region of the CbuD1884 protein trafficked to the endoplasmic reticulum (ER), with the C terminus dispersed nonspecifically in the host cytoplasm. This new Dot/Icm substrate is now termed ElpA (ER-localizing protein A). Full-length ElpA triggered substantial disruption of ER structure and host cell secretory transport. These results suggest that ElpA is a pathotype-specific T4SS effector that influences ER function during C. burnetii infection.

  8. Type IV pilus glycosylation mediates resistance of Pseudomonas aeruginosa to opsonic activities of the pulmonary surfactant protein A.

    PubMed

    Tan, Rommel M; Kuang, Zhizhou; Hao, Yonghua; Lee, Francis; Lee, Timothy; Lee, Ryan J; Lau, Gee W

    2015-04-01

    Pseudomonas aeruginosa is a major bacterial pathogen commonly associated with chronic lung infections in cystic fibrosis (CF). Previously, we have demonstrated that the type IV pilus (Tfp) of P. aeruginosa mediates resistance to antibacterial effects of pulmonary surfactant protein A (SP-A). Interestingly, P. aeruginosa strains with group I pilins are O-glycosylated through the TfpO glycosyltransferase with a single subunit of O-antigen (O-ag). Importantly, TfpO-mediated O-glycosylation is important for virulence in mouse lungs, exemplified by more frequent lung infection in CF with TfpO-expressing P. aeruginosa strains. However, the mechanism underlying the importance of Tfp glycosylation in P. aeruginosa pathogenesis is not fully understood. Here, we demonstrated one mechanism of increased fitness mediated by O-glycosylation of group 1 pilins on Tfp in the P. aeruginosa clinical isolate 1244. Using an acute pneumonia model in SP-A+/+ versus SP-A-/- mice, the O-glycosylation-deficient ΔtfpO mutant was found to be attenuated in lung infection. Both 1244 and ΔtfpO strains showed equal levels of susceptibility to SP-A-mediated membrane permeability. In contrast, the ΔtfpO mutant was more susceptible to opsonization by SP-A and by other pulmonary and circulating opsonins, SP-D and mannose binding lectin 2, respectively. Importantly, the increased susceptibility to phagocytosis was abrogated in the absence of opsonins. These results indicate that O-glycosylation of Tfp with O-ag specifically confers resistance to opsonization during host-mediated phagocytosis.

  9. Spectroscopic Studies of Abiotic and Biological Nanomaterials: Silver Nanoparticles, Rhodamine 6G Adsorbed on Graphene, and c-Type Cytochromes and Type IV Pili in Geobacter sulfurreducens

    NASA Astrophysics Data System (ADS)

    Thrall, Elizabeth S.

    This thesis describes spectroscopic studies of three different systems: silver nanoparticles, the dye molecule rhodamine 6G adsorbed on graphene, and the type IV pili and c-type cytochromes produced by the dissimilatory metal-reducing bacterium Geobacter sulfurreducens. Although these systems are quite different in some ways, they can all be considered examples of nanomaterials. A nanomaterial is generally defined as having at least one dimension below 100 nm in size. Silver nanoparticles, with sub-100 nm size in all dimensions, are examples of zero-dimensional nanomaterials. Graphene, a single atomic layer of carbon atoms, is the paradigmatic two-dimensional nanomaterial. And although bacterial cells are on the order of 1 μm in size, the type IV pili and multiheme c-type cytochromes produced by G. sulfurreducens can be considered to be one- and zero-dimensional nanomaterials respectively. A further connection between these systems is their strong interaction with visible light, allowing us to study them using similar spectroscopic tools. The first chapter of this thesis describes research on the plasmon-mediated photochemistry of silver nanoparticles. Silver nanoparticles support coherent electron oscillations, known as localized surface plasmons, at resonance frequencies that depend on the particle size and shape and the local dielectric environment. Nanoparticle absorption and scattering cross-sections are maximized at surface plasmon resonance frequencies, and the electromagnetic field is amplified near the particle surface. Plasmonic effects can enhance the photochemistry of silver particles alone or in conjunction with semiconductors according to several mechanisms. We study the photooxidation of citrate by silver nanoparticles in a photoelectrochemical cell, focusing on the wavelength-dependence of the reaction rate and the role of the semiconductor substrate. We find that the citrate

  10. Roles of the Putative Type IV-like Secretion System Key Component VirD4 and PrsA in Pathogenesis of Streptococcus suis Type 2

    PubMed Central

    Jiang, Xiaowu; Yang, Yunkai; Zhou, Jingjing; Zhu, Lexin; Gu, Yuanxing; Zhang, Xiaoyan; Li, Xiaoliang; Fang, Weihuan

    2016-01-01

    Streptococcus suis type 2 (SS2) is a zoonotic pathogen causing septic infection, meningitis and pneumonia in pigs and humans. SS2 may cause streptococcal toxic shock syndrome (STSS) probably due to excessive release of inflammatory cytokines. A previous study indicated that the virD4 gene in the putative type IV-like secretion system (T4SS) within the 89K pathogenicity island specific for recent epidemic strains contributed to the development of STSS. However, the functional basis of VirD4 in STSS remains unclear. Here we show that deletion of virD4 led to reduced virulence as shown by about 65% higher LD50, lower bacterial load in liver and brain, and lower level of expression of inflammatory cytokines in mice and cell lines than its parent strain. The ΔVirD4 mutant was more easily phagocytosed, suggesting its role as an anti-phagocytic factor. Oxidative stress that mimic bacterial exposure to respiratory burst of phagocytes upregulated expression of virD4. Proteomic analysis identified 10 secreted proteins of significant differences between the parent and mutant strains under oxidative stress, including PrsA, a peptidyl-prolyl isomerase. The SS2 PrsA expressed in E. coli caused a dose-dependent cell death and increased expression of proinflammatory IL-1β, IL-6 and TNF-α in murine macrophage cells. Our data provide novel insights into the contribution of the VirD4 factor to STSS pathogenesis, possibly via its anti-phagocytic activity, upregulation of its expression upon oxidative stress and its involvement in increased secretion of PrsA as a cell death inducer and proinflammatory effector. PMID:27995095

  11. Functional interactions of VirB11 traffic ATPases with VirB4 and VirD4 molecular motors in type IV secretion systems.

    PubMed

    Ripoll-Rozada, Jorge; Zunzunegui, Sandra; de la Cruz, Fernando; Arechaga, Ignacio; Cabezón, Elena

    2013-09-01

    Pilus biogenesis and substrate transport by type IV secretion systems require energy, which is provided by three molecular motors localized at the base of the secretion channel. One of these motors, VirB11, belongs to the superfamily of traffic ATPases, which includes members of the type II secretion system and the type IV pilus and archaeal flagellar assembly apparatus. Here, we report the functional interactions between TrwD, the VirB11 homolog of the conjugative plasmid R388, and TrwK and TrwB, the motors involved in pilus biogenesis and DNA transport, respectively. Although these interactions remained standing upon replacement of the traffic ATPase by a homolog from a phylogenetically related conjugative system, namely, TraG of plasmid pKM101, this homolog could not replace the TrwD function for DNA transfer. This result suggests that VirB11 works as a switch between pilus biogenesis and DNA transport and reinforces a mechanistic model in which VirB11 proteins act as traffic ATPases by regulating both events in type IV secretion systems.

  12. Cytotoxicity of Brucella smooth strains for macrophages is mediated by increased secretion of the type IV secretion system.

    PubMed

    Zhong, Zhijun; Wang, Yufei; Qiao, Feng; Wang, Zhoujia; Du, Xinying; Xu, Jie; Zhao, Jin; Qu, Qing; Dong, Shicun; Sun, Yansong; Huang, Liuyu; Huang, Kehe; Chen, Zeliang

    2009-10-01

    Some Brucella rough mutants cause cytotoxicity that resembles oncosis and necrosis in macrophages. This cytotoxicity requires the type IV secretion system (T4SS). In rough mutants, the cell-surface O antigen is shortened and the T4SS structure is thus exposed on the surface. Cytotoxicity effector proteins can therefore be more easily secreted. This enhanced secretion of effector proteins might cause the increased levels of cytotoxicity observed. However, whether this cytotoxicity is unique to the rough mutant and is mediated by overexpression of the T4SS has not been definitively determined. To test this, in the present study, a virB inactivation mutant (BMDeltavirB) and an overexpression strain (BM-VIR) of a smooth Brucella melitensis strain (BM) were constructed and their cytotoxicity for macrophages and intracellular survival capability were analysed and compared. Cytotoxicity was detected in macrophages infected with higher concentrations of strains BM or BM-VIR, but not in those infected with BMDeltavirB. The quorum sensing signal molecule N-dodecanoyl-dl-homoserine lactone (C(12)-HSL), a molecule that can inhibit expression of virB, inhibited the cytotoxicity of BM and BM-VIR, but not of BMDeltavirB. These results indicated that overexpression of virB is responsible for Brucella cytotoxicity in macrophages. Transcription analysis showed that virB is regulated in a cell-density-dependent manner both in in vitro culture and during macrophage infection. When compared with BM, BM-VIR showed a reduced survival capacity in macrophages and mice, but both strains demonstrated similar resistance to in vitro stress conditions designed to simulate intracellular environments. Taken together, the cytotoxicity of Brucella for macrophages is probably mediated by increased secretion of effector proteins that results from overexpression of virB or an increase in the number of bacterial cells. The observation that both inactivation and overexpression of virB are detrimental

  13. Resolution of Large Azygos Vein Aneurysm Following Stent-Graft Shunt Placement in a Patient with Ehlers-Danlos Syndrome Type IV

    SciTech Connect

    D'Souza, Estelle S.; Williams, David M.; Deeb, G.M.; Cwikiel, Wojciech

    2006-10-15

    Ehlers-Danlos syndrome (EDS) type IV is a rare connective tissue disorder associated with thin-walled, friable arteries and veins predisposing patients to aneurysm formation, dissection, fistula formation, and vessel rupture. Azygos vein aneurysm is an extremely rare condition which has not been reported in association with EDS in the literature. We present a patient with EDS type IV and interrupted inferior vena cava (IVC) with azygos continuation who developed an azygos vein aneurysm. In order to decrease flow through the azygos vein and reduce the risk of aneurysm rupture, a stent-graft shunt was created from the right hepatic vein to the azygos vein via a transhepatic, retroperitoneal route. At 6 month follow-up the shunt was open and the azygos vein aneurysm had resolved.

  14. Comparative analysis of the noncollagenous NC1 domain of type IV collagen: identification of structural features important for assembly, function, and pathogenesis.

    PubMed

    Netzer, K O; Suzuki, K; Itoh, Y; Hudson, B G; Khalifah, R G

    1998-06-01

    Type IV collagen alpha1-alpha6 chains have important roles in the assembly of basement membranes and are implicated in the pathogenesis of Goodpasture syndrome, an autoimmune disorder, and Alport syndrome, a hereditary renal disease. We report comparative sequence analyses and structural predictions of the noncollagenous C-terminal globular NC1 domain (28 sequences). The inferred tree verified that type IV collagen sequences fall into two groups, alpha1-like and alpha2-like, and suggested that vertebrate alpha3/alpha4 sequences evolved before alpha1/alpha2 and alpha5/alpha6. About one fifth of NC1 residues were identified to confer either the alpha1 or alpha2 group-specificity. These residues accumulate opposite charge in subdomain B of alpha1 (positive) and alpha2 (negative) sequences and may play a role in the stoichiometric chain selection upon type IV collagen assembly. Neural network secondary structure prediction on multiple aligned sequences revealed a subdomain core structure consisting of six hydrophobic beta-strands and one short alpha-helix with a significant hydrophobic moment. The existence of opposite charges in the alpha-helices may carry implications for intersubdomain interactions. The results provide a rationale for defining the epitope that binds Goodpasture autoantibodies and a framework for understanding how certain NC1 mutations may lead to Alport syndrome. A search algorithm, based entirely on amino acid properties, yielded a possible similarity of NC1 to tissue inhibitor of metalloproteinases (TIMP) and prompted an investigation of a possible functional relationship. The results indicate that NC1 preparations decrease the activity of matrix metalloproteinases 2 and 3 (MMP-2, MMP-3) toward a peptide substrate, though not to [14C]-gelatin. We suggest that an ancestral NC1 may have been incorporated into type IV collagen as an evolutionarily mobile domain carrying proteinase inhibitor function.

  15. Salter-Harris Type-IV injuries of the distal tibial epiphyseal growth plate, with emphasis on those involving the medial malleolus.

    PubMed

    Cass, J R; Peterson, H A

    1983-10-01

    Salter-Harris Type-IV fractures of the epiphysis extend through the articular cartilage, epiphysis, physis, and metaphysis and have a high rate of complications secondary to premature partial closure of the physis. In this study we attempted to determine which Type-IV fractures of the distal end of the tibia result in premature partial closure, how the various treatment modalities affect the risk of premature physeal closure, and how the complication itself might be best managed. Thirty-two Type-IV fractures of the distal end of the tibia were seen at the Mayo Clinic during a five-year period. Eighteen injuries involved the medial malleolus, thirteen were so-called triplane fractures, and one was a fracture of the lateral part of the plafond. In the eighteen ankles with a fracture that involved the medial malleolus, extension of the fracture into the metaphysis could often be appreciated only on oblique roentgenograms. The patients' ages at the time of fracture ranged from one year and one month to fifteen years and six months old. In nine of the eighteen tibiae with a fracture of the medial malleolus premature partial closure of the distal physis developed, resulting in angular deformity or limb-length discrepancy sufficient to require operative treatment (epiphyseodesis, corrective osteotomy, or excision of a physeal bar). A physeal bar was best detected by tomograms made in two planes and by scanograms. Bar formation may be treated by excision of the bar, arrest of the whole physis, osteotomy, or combinations of these procedures. Of the thirteen patients with a triplane fracture and the one with a Type-IV fracture of the lateral part of the plafond, all fourteen were near maturity at the time of injury, and no growth-arrest problems developed.

  16. Interaction with CagF Is Required for Translocation of CagA into the Host via the Helicobacter pylori Type IV Secretion System

    PubMed Central

    Couturier, Marc Roger; Tasca, Elizabetta; Montecucco, Cesare; Stein, Markus

    2006-01-01

    Development of severe gastric diseases is strongly associated with those strains of Helicobacter pylori that contain the cag pathogenicity island (PAI) inserted into the chromosome. The cag PAI encodes a type IV secretion system that translocates the major disease-associated virulence protein, CagA, into the host epithelial cell. CagA then affects host signaling pathways, leading to cell elongations and inflammation. Since the precise mechanism by which the CagA toxin is translocated by the type IV secretion system remained elusive, we used fusion proteins and immunoprecipitation studies to identify CagA-interacting secretion components. Here we demonstrate that CagA, in addition to other yet-unidentified proteins, interacts with CagF, presumably at the inner bacterial membrane. This interaction is required for CagA translocation, since an isogenic nonpolar cagF mutant was translocation deficient. Our results suggest that CagF may be a protein with unique chaperone-like function that is involved in the early steps of CagA recognition and delivery into the type IV secretion channel. PMID:16368981

  17. Phlorizin, an Active Ingredient of Eleutherococcus senticosus, Increases Proliferative Potential of Keratinocytes with Inhibition of MiR135b and Increased Expression of Type IV Collagen.

    PubMed

    Choi, Hye-Ryung; Nam, Kyung-Mi; Lee, Hyun-Sun; Yang, Seung-Hye; Kim, Young-Soo; Lee, Jongsung; Date, Akira; Toyama, Kazumi; Park, Kyoung-Chan

    2016-01-01

    E. senticosus extract (ESE), known as antioxidant, has diverse pharmacologic effects. It is also used as an antiaging agent for the skin and phlorizin (PZ) is identified as a main ingredient. In this study, the effects of PZ on epidermal stem cells were investigated. Cultured normal human keratinocytes and skin equivalents are used to test whether PZ affects proliferative potential of keratinocytes and how it regulates these effects. Skin equivalents (SEs) were treated with ESE and the results showed that the epidermis became slightly thickened on addition of 0.002% ESE. The staining intensity of p63 as well as proliferating cell nuclear antigen (PCNA) is increased, and integrin α6 was upregulated. Analysis of ESE confirmed that PZ is the main ingredient. When SEs were treated with PZ, similar findings were observed. In particular, the expression of integrin α6, integrin β1, and type IV collagen was increased. Levels of mRNA for type IV collagen were increased and levels of miR135b were downregulated. All these findings suggested that PZ can affect the proliferative potential of epidermal cells in part by microenvironment changes via miR135b downregulation and following increased expression of type IV collagen.

  18. Phlorizin, an Active Ingredient of Eleutherococcus senticosus, Increases Proliferative Potential of Keratinocytes with Inhibition of MiR135b and Increased Expression of Type IV Collagen

    PubMed Central

    Choi, Hye-Ryung; Nam, Kyung-Mi; Lee, Hyun-Sun; Yang, Seung-Hye; Kim, Young-Soo; Lee, Jongsung; Date, Akira; Toyama, Kazumi; Park, Kyoung-Chan

    2016-01-01

    E. senticosus extract (ESE), known as antioxidant, has diverse pharmacologic effects. It is also used as an antiaging agent for the skin and phlorizin (PZ) is identified as a main ingredient. In this study, the effects of PZ on epidermal stem cells were investigated. Cultured normal human keratinocytes and skin equivalents are used to test whether PZ affects proliferative potential of keratinocytes and how it regulates these effects. Skin equivalents (SEs) were treated with ESE and the results showed that the epidermis became slightly thickened on addition of 0.002% ESE. The staining intensity of p63 as well as proliferating cell nuclear antigen (PCNA) is increased, and integrin α6 was upregulated. Analysis of ESE confirmed that PZ is the main ingredient. When SEs were treated with PZ, similar findings were observed. In particular, the expression of integrin α6, integrin β1, and type IV collagen was increased. Levels of mRNA for type IV collagen were increased and levels of miR135b were downregulated. All these findings suggested that PZ can affect the proliferative potential of epidermal cells in part by microenvironment changes via miR135b downregulation and following increased expression of type IV collagen. PMID:27042261

  19. Endovenous surgery for recurrent varicose veins with a one-year follow up in a patient with Ehlers Danlos syndrome type IV.

    PubMed

    Whiteley, Mark S; Holdstock, Judith M

    2015-08-01

    We present a woman with severe symptomatic recurrent varicose veins who was treated with endovenous laser ablation and transluminal occlusion of perforator with attempted phlebectomies for extensive varices. The phlebectomies turned out to be near impossible due to friability of the veins. Her treatment was completed with post-operative ultrasound guided foam sclerotherapy seven months later. She was subsequently diagnosed as Ehlers Danlos syndrome type IV. A duplex ultrasound scan 18 months post-endovenous laser ablation and transluminal occlusion of perforator and 11 months after ultrasound guided foam sclerotherapy confirmed successful closure with virtual atrophy of all treated veins. She was found to be reflux free and only showed a few scattered cosmetic reticular veins. Open varicose vein surgery has been reported as being hazardous in the past in a patient with Ehlers Danlos syndrome type IV. Our experience has shown that endovenous laser ablation, transluminal occlusion of perforator and ultrasound guided foam sclerotherapy appear to be effective in treating this patient with Ehlers Danlos syndrome type IV, although phlebectomies were technically impossible.

  20. [Evidence-based evaluation of the effect of Type IV Allergies on the reduction of fitness for work. Survey of occupational skin diseases].

    PubMed

    Diepgen, T L; Dickel, H; Becker, D; Geier, J; Mahler, V; Schmidt, A; Schwanitz, H-J; Skudlik, C; Wagner, E; Wehrmann, W; Weisshaar, E; Werfel, T; Blome, O

    2005-03-01

    Evidence-based guidelines about the distribution of type IV allergens of the European standard series in different professions and its occupational relevance are missing. Based on published data, epidemiological investigations, work related knowledge about industrial processes, and allergen specific properties, recommendations are given about the clinical impact in the working environment for the following allergens: acrylates/methacrylates, epoxy resins, dichromate, cobalt, nickel, formaldehyde, (chlor-)methylisothiazolone, p-phenylendiamine, colophony, thiurame, mercaptobenzothiazole, dithiocarbamate, n-isopropyl-n'-phenyl-p-phenylendiamine, fragrance mix, composite mix, and neomycinsulfate. These recommendations might improve the clearance rate and allergological evaluation of the occupational relevance of different delayed type sensitizations or allergens.

  1. EffectiveDB—updates and novel features for a better annotation of bacterial secreted proteins and Type III, IV, VI secretion systems

    PubMed Central

    Eichinger, Valerie; Nussbaumer, Thomas; Platzer, Alexander; Jehl, Marc-André; Arnold, Roland; Rattei, Thomas

    2016-01-01

    Protein secretion systems play a key role in the interaction of bacteria and hosts. EffectiveDB (http://effectivedb.org) contains pre-calculated predictions of bacterial secreted proteins and of intact secretion systems. Here we describe a major update of the database, which was previously featured in the NAR Database Issue. EffectiveDB bundles various tools to recognize Type III secretion signals, conserved binding sites of Type III chaperones, Type IV secretion peptides, eukaryotic-like domains and subcellular targeting signals in the host. Beyond the analysis of arbitrary protein sequence collections, the new release of EffectiveDB also provides a ‘genome-mode’, in which protein sequences from nearly complete genomes or metagenomic bins can be screened for the presence of three important secretion systems (Type III, IV, VI). EffectiveDB contains pre-calculated predictions for currently 1677 bacterial genomes from the EggNOG 4.0 database and for additional bacterial genomes from NCBI RefSeq. The new, user-friendly and informative web portal offers a submission tool for running the EffectiveDB prediction tools on user-provided data. PMID:26590402

  2. Discovery and structural characterisation of new fold type IV-transaminases exemplify the diversity of this enzyme fold

    PubMed Central

    Pavkov-Keller, Tea; Strohmeier, Gernot A.; Diepold, Matthias; Peeters, Wilco; Smeets, Natascha; Schürmann, Martin; Gruber, Karl; Schwab, Helmut; Steiner, Kerstin

    2016-01-01

    Transaminases are useful biocatalysts for the production of amino acids and chiral amines as intermediates for a broad range of drugs and fine chemicals. Here, we describe the discovery and characterisation of new transaminases from microorganisms which were enriched in selective media containing (R)-amines as sole nitrogen source. While most of the candidate proteins were clearly assigned to known subgroups of the fold IV family of PLP-dependent enzymes by sequence analysis and characterisation of their substrate specificity, some of them did not fit to any of these groups. The structure of one of these enzymes from Curtobacterium pusillum, which can convert d-amino acids and various (R)-amines with high enantioselectivity, was solved at a resolution of 2.4 Å. It shows significant differences especially in the active site compared to other transaminases of the fold IV family and thus indicates the existence of a new subgroup within this family. Although the discovered transaminases were not able to convert ketones in a reasonable time frame, overall, the enrichment-based approach was successful, as we identified two amine transaminases, which convert (R)-amines with high enantioselectivity, and can be used for a kinetic resolution of 1-phenylethylamine and analogues to obtain the (S)-amines with e.e.s >99%. PMID:27905516

  3. Discovery and structural characterisation of new fold type IV-transaminases exemplify the diversity of this enzyme fold.

    PubMed

    Pavkov-Keller, Tea; Strohmeier, Gernot A; Diepold, Matthias; Peeters, Wilco; Smeets, Natascha; Schürmann, Martin; Gruber, Karl; Schwab, Helmut; Steiner, Kerstin

    2016-12-01

    Transaminases are useful biocatalysts for the production of amino acids and chiral amines as intermediates for a broad range of drugs and fine chemicals. Here, we describe the discovery and characterisation of new transaminases from microorganisms which were enriched in selective media containing (R)-amines as sole nitrogen source. While most of the candidate proteins were clearly assigned to known subgroups of the fold IV family of PLP-dependent enzymes by sequence analysis and characterisation of their substrate specificity, some of them did not fit to any of these groups. The structure of one of these enzymes from Curtobacterium pusillum, which can convert d-amino acids and various (R)-amines with high enantioselectivity, was solved at a resolution of 2.4 Å. It shows significant differences especially in the active site compared to other transaminases of the fold IV family and thus indicates the existence of a new subgroup within this family. Although the discovered transaminases were not able to convert ketones in a reasonable time frame, overall, the enrichment-based approach was successful, as we identified two amine transaminases, which convert (R)-amines with high enantioselectivity, and can be used for a kinetic resolution of 1-phenylethylamine and analogues to obtain the (S)-amines with e.e.s >99%.

  4. Expression and activity profiles of DPP IV/CD26 and NEP/CD10 glycoproteins in the human renal cancer are tumor-type dependent

    PubMed Central

    2010-01-01

    Background Cell-surface glycoproteins play critical roles in cell-to-cell recognition, signal transduction and regulation, thus being crucial in cell proliferation and cancer etiogenesis and development. DPP IV and NEP are ubiquitous glycopeptidases closely linked to tumor pathogenesis and development, and they are used as markers in some cancers. In the present study, the activity and protein and mRNA expression of these glycoproteins were analysed in a subset of clear-cell (CCRCC) and chromophobe (ChRCC) renal cell carcinomas, and in renal oncocytomas (RO). Methods Peptidase activities were measured by conventional enzymatic assays with fluorogen-derived substrates. Gene expression was quantitatively determined by qRT-PCR and membrane-bound protein expression and distribution analysis was performed by specific immunostaining. Results The activity of both glycoproteins was sharply decreased in the three histological types of renal tumors. Protein and mRNA expression was strongly downregulated in tumors from distal nephron (ChRCC and RO). Moreover, soluble DPP IV activity positively correlated with the aggressiveness of CCRCCs (higher activities in high grade tumors). Conclusions These results support the pivotal role for DPP IV and NEP in the malignant transformation pathways and point to these peptidases as potential diagnostic markers. PMID:20459800

  5. Fetal type IV glycogen storage disease: clinical, enzymatic, and genetic data of a pure muscular form with variable and early antenatal manifestations in the same family.

    PubMed

    L'herminé-Coulomb, A; Beuzen, F; Bouvier, R; Rolland, M O; Froissart, R; Menez, F; Audibert, F; Labrune, P

    2005-12-01

    We report on a family of three consecutive fetuses affected by type IV glycogen storage disease (GSD IV). In all cases, cervical cystic hygroma was observed on the 12-week-ultrasound examination. During the second trimester, fetal hydrops developed in the first pregnancy whereas fetal akinesia appeared in the second pregnancy. The diagnosis was suggested by microscopic examination of fetal tissues showing characteristic inclusions exclusively in striated fibers, then confirmed by enzymatic studies on frozen muscle. Antenatal diagnosis was performed on the third and fourth pregnancies: cervical cystic hygroma and low glycogen branching enzyme (GBE) activity on chorionic villi sample (CVS) were detected in the third pregnancy whereas ultrasound findings were normal and GBE activity within normal range on CVS in the fourth pregnancy. Molecular analysis showed that the mother was heterozygous for a c.1471G > C mutation in exon 12, leading to the replacement of an alanine by a tyrosine at codon 491 (p.A491T); the father was heterozygous for a c.895G > T mutation in exon 7, leading to the creation of a stop codon at position 299 (p.G299X). GSD IV has to be considered in a context of cervical cystic hygroma with normal karyotype, particularly when second trimester hydrops or akinesia develop. Enzymatic analysis of GBE must be performed on CVS or amniotic cells to confirm the diagnosis. Characteristic intracellular inclusions are specific to the disease and should be recognized, even in macerated tissues after fetal death. Genetic analysis of the GBE gene may help to shed some light on the puzzling diversity of GSD IV phenotypes.

  6. Highly Isospecific Polymerization of Silyl-Protected ω-Alkenols Using an [OSSO]-Type Bis(phenolato) Dichloro Zirconium(IV) Precatalyst.

    PubMed

    Saito, Yusuke; Nakata, Norio; Ishii, Akihiko

    2016-06-01

    The coordination polymerization of silyl-protected ω-alkenols such as ω-alken-α-oxytriisopropylsilanes 1 provides poly(ω-alkenyl-α-oxytriisopropylsilalne)s with a highly isospecific microstructure ([mmmm] > 95%) when a combination of [OSSO]-type bis(phenolato) dichloro zirconium(IV) complex 2 and dried methylaluminoxane is used as the precatalyst and activator, respectively. The resulting siloxy-substituted polymers could be efficiently transformed into the corresponding functionalized polyolefins, which contained up to 90% acetyl groups and ≈7% hydroxy groups in the terminal side chains.

  7. Incidence and specificity of antibodies to types I, II, III, IV, and V collagen in rheumatoid arthritis and other rheumatic diseases as measured by 125I-radioimmunoassay

    SciTech Connect

    Stuart, J.M.; Huffstutter, E.H.; Townes, A.S.; Kang, A.H.

    1983-07-01

    Antibodies to human native and denatured types I, II, III, IV, and V collagens were measured using 125I-radioimmunoassay. Mean levels of binding by sera from 30 rheumatoid arthritis patients were significantly higher than those from 20 normal subjects against all of the collagens tested. The relative antibody concentration was higher in synovial fluid than in simultaneously obtained serum. Many patients with gout or various other rheumatic diseases also had detectable anticollagen antibodies. With a few notable exceptions, the majority of the reactivity detected in all patient groups was directed against covalent structural determinants present on all of the denatured collagens, suggesting a secondary reaction to tissue injury.

  8. Hypotheses, rationale, design, and methods for prognostic evaluation in type 2 diabetic patients with angiographically normal coronary arteries. The MASS IV-DM Trial

    PubMed Central

    2010-01-01

    Background The MASS IV-DM Trial is a large project from a single institution, the Heart Institute (InCor), University of São Paulo Medical School, Brazil to study ventricular function and coronary arteries in patients with type 2 diabetes mellitus. Methods/Design The study will enroll 600 patients with type 2 diabetes who have angiographically normal ventricular function and coronary arteries. The goal of the MASS IV-DM Trial is to achieve a long-term evaluation of the development of coronary atherosclerosis by using angiograms and coronary-artery calcium scan by electron-beam computed tomography at baseline and after 5 years of follow-up. In addition, the incidence of major cardiovascular events, the dysfunction of various organs involved in this disease, particularly microalbuminuria and renal function, will be analyzed through clinical evaluation. In addition, an effort will be made to investigate in depth the presence of major cardiovascular risk factors, especially the biochemical profile, metabolic syndrome inflammatory activity, oxidative stress, endothelial function, prothrombotic factors, and profibrinolytic and platelet activity. An evaluation will be made of the polymorphism as a determinant of disease and its possible role in the genesis of micro- and macrovascular damage. Discussion The MASS IV-DM trial is designed to include diabetic patients with clinically suspected myocardial ischemia in whom conventional angiography shows angiographically normal coronary arteries. The result of extensive investigation including angiographic follow-up by several methods, vascular reactivity, pro-thrombotic mechanisms, genetic and biochemical studies may facilitate the understanding of so-called micro- and macrovascular disease of DM. PMID:20920271

  9. Flagella but not type IV pili are involved in the initial adhesion of Pseudomonas aeruginosa PAO1 to hydrophobic or superhydrophobic surfaces.

    PubMed

    Bruzaud, Jérôme; Tarrade, Jeanne; Coudreuse, Arnaud; Canette, Alexis; Herry, Jean-Marie; Taffin de Givenchy, Elisabeth; Darmanin, Thierry; Guittard, Frédéric; Guilbaud, Morgan; Bellon-Fontaine, Marie-Noëlle

    2015-07-01

    Over the last decades, surface biocontamination has become a major concern in food industries and medical environments where its outcomes could vary from financial losses to public health issues. Understanding adhesion mechanisms of involved microorganisms is essential to develop new strategies of prevention and control. Adhesion of Pseudomonas aeruginosa, a nosocomial pathogenic bacterium, relies on several bacterial features, among which are bacterial appendages such as flagella and type IV pili. Here, we examine the role of P. aeruginosa PAO1 flagella and type IV pili in the adhesion to abiotic surfaces with various hydrophobicities. Adhesion kinetics showed, that after 60min, flagella increased the adhesion of the strain to surfaces with high hydrophobicity while no effect was observed on hydrophilic surfaces. Flagella of adherent bacteria exhibited specific and conserved pattern on the surfaces that suggested a higher affinity of flagella for hydrophobic surfaces. Based on these results and on previous studies in the literature, we proposed a model of flagella-mediated adhesion onto hydrophobic surfaces where these appendages induce the first contact and promote the adhesion of the bacterial body. These findings suggest that anti-bioadhesive surface design should take into consideration the presence of bacterial appendages.

  10. Type-IV pili spectroscopic markers: applications in the quantification of piliation levels in Moraxella bovis cells by a FT-IR ANN-based model.

    PubMed

    Bosch, Alejandra; Prieto, Claudia; Serra, Diego Omar; Martina, Pablo; Stämmbler, Maren; Naumann, Dieter; Schmitt, Jürgen; Yantorno, Osvaldo

    2010-08-01

    Type-IV pili are cell surface organelles found in a wide variety of Gram-negative bacteria. They have traditionally been detected by electron microscopy and ELISA techniques. However, these methodologies are not appropriate for the rapid discrimination and quantification of piliated and nonpiliated cells in industrial or field conditions. Here, the analysis of FT-IR spectra of piliated, nonpiliated and sheared Moraxella bovis cells, together with purified pili suspensions spectra, allowed the identification of 3 IR regions associated to spectroscopic markers of Type-IV pili: 1750-1600, 1450-1350 and 1280-950 cm(-1). Such IR-specific markers were found for piliated cells grown in different culture systems (liquid or solid media), independently of the strain or pili serotype. They were also sensitive to pili expression levels. Therefore, on the bases of these specific spectral features, an FT-IR ANN-based model was developed to classify piliation levels in 5 distinct groups. An overall classification rate of almost 90% demonstrates the strong potential of the ANN system developed to monitor M. bovis cultures in vaccine production.

  11. Cag-delta (Cag3) protein from the Helicobacter pylori 26695 cag type IV secretion system forms ring-like supramolecular assemblies.

    PubMed

    Smart, Jonathan; Fouillen, Aurélien; Casu, Bastien; Nanci, Antonio; Baron, Christian

    2017-01-01

    Helicobacter pylori is an important cause of gastric pathologies and persistent infection can lead to stomach cancer. Virulent H. pylori strains encode a type IV secretion system responsible for translocation of the oncogenic CagA protein into cells of the gastric mucosa. Gene HP0522 encodes the essential component Cagδ (Cag3), and we show by gel filtration and cross-linking that purified Cagδ forms high molecular mass complexes. In contrast, its interaction partner CagT is mostly monomeric, but co-fractionates after gel filtration. Analysis by transmission electron microscopy revealed that purified Cagδ complexes can self-assemble ring-like structures. Cagδ-overexpressing Escherichia coli exhibits membrane-associated circular profiles in regions of the cell envelope with intense immunogold labelling with a Cagδ-specific antiserum. Our results suggest that Cagδ has the capacity to form macromolecular structures contributing to the assembly of the type IV secretion system.

  12. The effects of MucR on expression of type IV secretion system, quorum sensing system and stress responses in Brucella melitensis.

    PubMed

    Dong, Hao; Liu, Wenxiao; Peng, Xiaowei; Jing, Zhigang; Wu, Qingmin

    2013-10-25

    MucR is a transcriptional regulator in many bacterial pathogens and is required for virulence in mice and macrophages, resistance to stress responses, and modification of the cell envelope in Brucella spp. To determine why the mucR deleted mutant is attenuated in vivo and in vitro, we performed RNA-seq analysis using Brucella melitensis RNA obtained from B. melitensis 16M and 16MΔmucR grown under the same conditions. We found 442 differentially expressed genes; 310 were over expressed, and 132 were less expressed in 16MΔmucR. Many genes identified are involved in metabolism, cell wall/envelope biogenesis, replication, and translation. Notably, genes involved in type IV secretion system and quorum sensing system were down-regulated in 16MΔmucR. In addition, genes involved in tolerance to acid and iron-limitation were also affected and experimentally verified in this study. The effects of MucR on Brucella survival and persistence in mice and macrophages were related to type IV secretion system, quorum sensing system, and stress tolerance, which also provide added insight to the MucR regulon.

  13. Calcium/calmodulin-dependent protein kinase type IV is a target gene of the Wnt/beta-catenin signaling pathway.

    PubMed

    Arrázola, Macarena S; Varela-Nallar, Lorena; Colombres, Marcela; Toledo, Enrique M; Cruzat, Fernando; Pavez, Leonardo; Assar, Rodrigo; Aravena, Andrés; González, Mauricio; Montecino, Martín; Maass, Alejandro; Martínez, Servet; Inestrosa, Nibaldo C

    2009-12-01

    Calcium/calmodulin-dependent protein kinase IV (CaMKIV) plays a key role in the regulation of calcium-dependent gene expression. The expression of CaMKIV and the activation of CREB regulated genes are involved in memory and neuronal survival. We report here that: (a) a bioinformatic analysis of 15,476 promoters of the human genome predicted several Wnt target genes, being CaMKIV a very interesting candidate; (b) CaMKIV promoter contains TCF/LEF transcription motifs similar to those present in Wnt target genes; (c) biochemical studies indicate that lithium and the canonical ligand Wnt-3a induce CaMKIV mRNA and protein expression levels in rat hippocampal neurons as well as CaMKIV promoter activity; (d) treatment of hippocampal neurons with Wnt-3a increases the binding of beta-catenin to the CaMKIV promoter: (e) In vivo activation of the Wnt signaling improve spatial memory impairment and restores the expression of CaMKIV in a mice double transgenic model for Alzheimer's disease which shows decreased levels of the kinase. We conclude that CaMKIV is regulated by the Wnt signaling pathway and that its expression could play a role in the neuroprotective function of the Wnt signaling against the Alzheimer's amyloid peptide.

  14. Salter-Harris type III and IV displaced fracture of the hallux in young gymnasts: A series of four cases at 1-year follow-up.

    PubMed

    Perugia, Dario; Fabbri, Mattia; Guidi, Marco; Lepri, Marco; Masi, Vincenzo

    2014-12-01

    The purpose of this study was to describe four exceptional cases of Salter-Harris type III and IV fractures of the proximal phalanx of the hallux in young high-level gymnasts. All gymnasts underwent the same mechanism of injury of hyperadduction, which indicates a role of the abductor hallucis muscle in the genesis and displacement of these fractures. An open reduction and internal fixation was performed to achieve an anatomical reduction and avoid chronic disability. At 1-year follow-up, all patients had an excellent American Orthopaedic Foot and Ankle Society (AOFAS) score (100 points), and there was no shortening or angulation of the first ray and no evidence of degenerative joint disease on X-ray. Moreover, all the gymnasts had returned to pre-injury levels of sporting activity. To our knowledge, there are no previous studies that address these types of injuries and how they are handled in gymnasts.

  15. Welding IV.

    ERIC Educational Resources Information Center

    Allegheny County Community Coll., Pittsburgh, PA.

    Instructional objectives and performance requirements are outlined in this course guide for Welding IV, a competency-based course in advanced arc welding offered at the Community College of Allegheny County to provide students with proficiency in: (1) single vee groove welding using code specifications established by the American Welding Society…

  16. Crystal structures of lazulite-type oxidephosphates Ti IIITi IV3O 3(PO 4) 3 and MIII4Ti IV27O 24(PO 4) 24 ( MIII=Ti, Cr, Fe)

    NASA Astrophysics Data System (ADS)

    Schöneborn, M.; Glaum, R.; Reinauer, F.

    2008-06-01

    Single crystals of the oxidephosphates Ti IIITi IV3O 3(PO 4) 3 (black), Cr III4Ti IV27O 24(PO 4) 24 (red-brown, transparent), and Fe III4Ti IV27O 24(PO 4) 24 (brown) with edge-lengths up to 0.3 mm were grown by chemical vapour transport. The crystal structures of these orthorhombic members (space group F2 dd ) of the lazulite/lipscombite structure family were refined from single-crystal data [Ti IIITi IV3O 3(PO 4) 3: Z=24, a=7.3261(9) Å, b=22.166(5) Å, c=39.239(8) Å, R1=0.029, w R2=0.084, 6055 independent reflections, 301 variables; Cr III4Ti IV27O 24(PO 4) 24: Z=1, a=7.419(3) Å, b=21.640(5) Å, c=13.057(4) Å, R1=0.037, w R2=0.097, 1524 independent reflections, 111 variables; Fe III4Ti IV27O 24(PO 4) 24: Z=1, a=7.4001(9) Å, b=21.7503(2) Å, c=12.775(3) Å, R1=0.049, w R2=0.140, 1240 independent reflections, 112 variables). For Ti IIITi IVO 3(PO 4) 3 a well-ordered structure built from dimers [Ti III,IV2O 9] and [Ti IV,IV2O 9] and phosphate tetrahedra is found. The metal sites in the crystal structures of Cr 4Ti 27O 24(PO 4) 24 and Fe 4Ti 27O 24(PO 4) 24, consisting of dimers [ MIIITi IVO 9] and [Ti IV,IV2O 9], monomeric [Ti IVO 6] octahedra, and phosphate tetrahedra, are heavily disordered. Site disorder, leading to partial occupancy of all octahedral voids of the parent lipscombite/lazulite structure, as well as splitting of the metal positions is observed. According to Guinier photographs Ti III4Ti IV27O 24(PO 4) 24 ( a=7.418(2) Å, b=21.933(6) Å, c=12.948(7) Å) is isotypic to the oxidephosphates MIII4Ti IV27O 24(PO 4) 24 ( MIII: Cr, Fe). The UV/vis spectrum of Cr 4Ti 27O 24(PO 4) 24 reveals a rather small ligand-field splitting Δ o=14,370 cm -1 and a very low nephelauxetic ratio β=0.72 for the chromophores [Cr IIIO 6] within the dimers [Cr IIITi IVO 9].

  17. Characterization of type I, II, III, IV, and V collagens by time-resolved laser-induced fluorescence spectroscopy

    NASA Astrophysics Data System (ADS)

    Marcu, Laura; Cohen, David; Maarek, Jean-Michel I.; Grundfest, Warren S.

    2000-04-01

    The relative proportions of genetically distinct collagen types in connective tissues vary with tissue type and change during disease progression, development, wound healing, aging. This study aims to 1) characterize the spectro- temporal fluorescence emission of fiber different types of collagen and 2) assess the ability of time-resolved laser- induced fluorescence spectroscopy to distinguish between collagen types. Fluorescence emission of commercially available purified samples was induced with nitrogen laser excitation pulses and detected with a MCP-PMT connected to a digital storage oscilloscope. The recorded time-resolved emission spectra displayed distinct fluorescence emission characteristics for each collagen type. The time domain information complemented the spectral domain intensity data for improved discrimination between different collagen types. Our results reveal that analysis of the fluorescence emission can be used to characterize different species of collagen. Also, the results suggest that time-resolved spectroscopy can be used for monitoring of connective tissue matrix composition changes due to various pathological and non-pathological conditions.

  18. Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae. IV. The Fourth Year (2011-2012)

    NASA Astrophysics Data System (ADS)

    Kato, Taichi; Hambsch, Franz-Josef; Maehara, Hiroyuki; Masi, Gianluca; Miller, Ian; Noguchi, Ryo; Akasaka, Chihiro; Aoki, Tomoya; Kobayashi, Hiroshi; Matsumoto, Katsura; Nakagawa, Shinichi; Nakazato, Takuma; Nomoto, Takashi; Ogura, Kazuyuki; Ono, Rikako; Taniuchi, Keisuke; Stein, William; Henden, Arne; de Miguel, Enrique Kiyota, Seiichiro; Dubovsky, Pavol A.; Kudzej, Igor; Imamura, Kazuyoshi; Akazawa, Hidehiko; Takagi, Ryosuke; Wakabayashi, Yuya; Ogi, Minako; Tanabe, Kenji; Ulowetz, Joseph; Morelle, Etienne; Pickard, Roger D.; Ohshima, Tomohito; Kasai, Kiyoshi; Pavlenko, Elena P.; Antonyuk, Oksana I.; Baklanov, Aleksei V.; Antonyuk, Kirill; Samsonov, Denis; Pit, Nikolaj; Sosnovskij, Aleksei; Littlefield, Colin; Sabo, Richard; Ruiz, Javier; Krajci, Thomas; Dvorak, Shawn; Oksanen, Arto; Hirosawa, Kenji; Goff, William N.; Monard, Berto; Shears, Jeremy; Boyd, David; Voloshina, Irina B.; Shugarov, Sergey Yu.; Chochol, Drahomir; Miyashita, Atsushi; Pietz, Jochen; Katysheva, Natalia; Itoh, Hiroshi; Bolt, Greg; Andreev, Maksim V.; Parakhin, Nikolai; Malanushenko, Viktor; Martinelli, Fabio; Denisenko, Denis; Stockdale, Chris; Starr, Peter; Simonsen, Mike; Tristram, Paul J.; Fukui, Akihiko; Tordai, Tamas; Fidrich, Robert; Paxson, Kevin B.; Itagaki, Koh-ichi; Nakashima, Youichirou; Yoshida, Seiichi; Nishimura, Hideo; Kryachko, Timur V.; Samokhvalov, Andrey V.; Korotkiy, Stanislav A.; Satovski, Boris L.; Stubbings, Rod; Poyner, Gary; Muyllaert, Eddy; Gerke, Vladimir; MacDonald, Walter, II; Linnolt, Michael; Maeda, Yutaka; Hautecler, Hubert

    2013-02-01

    Continuing the project described by Kato et al. (2009, PASJ, 61, S395), we collected times of superhump maxima for 86 SU UMa-type dwarf novae, mainly observed during the 2011-2012 season. We confirmed general trends recorded in our previous studies, such as the relation between period derivatives and orbital periods. There are some systems showing positive period derivatives despite the long orbital period. We observed the 2011 outburst of the WZ Sge-type dwarf nova BW Scl, and recorded an O - C diagram similar to those of previously known WZ Sge-type dwarf novae. The WZ Sge-type dwarf nova OT J184228.1+483742 showed an unusual pattern of double outbursts composed of an outburst with early superhumps and one with ordinary superhumps. We propose an interpretation that a very small growth rate of the 3:1 resonance due to an extremely low mass-ratio led to quenching the superoutburst before the ordinary superhump appeared. We systematically studied ER UMa-type dwarf novae, and found that V1159 Ori showed positive superhumps similar to ER UMa in the 1990s. The recently recognized ER UMa-type object BK Lyn dominantly showed negative superhumps, and its behavior was very similar to the present-day state of ER UMa. The pattern of period variations in AM CVn-type objects was very similar to that of short-period hydrogen-rich SU UMa-type dwarf novae, making them a helium analogue of hydrogen-rich SU UMa-type dwarf novae. SBS 1108+574, a peculiar hydrogen-rich dwarf nova below the period minimum, showed a very similar pattern of period variations to those of short-period SU UMa-type dwarf novae. The mass-ratio derived from the detected orbital period suggests that this secondary is a somewhat evolved star whose hydrogen envelope was mostly stripped during the mass-exchange. CC Scl, MASTER OT J072948.66+593824.4, and OT J173516.9+154708 showed only low-amplitude superhumps with complex profiles. These superhumps are likely to be a combination of two closely separated periods.

  19. Improvement of diabetes, obesity and hypertension in type 2 diabetic KKA{sup y} mice by bis(allixinato)oxovanadium(IV) complex

    SciTech Connect

    Adachi, Yusuke; Yoshikawa, Yutaka; Yoshida, Jiro; Kodera, Yukihiro . E-mail: kodera_y@wakunaga.co.jp; Katoh, Akira . E-mail: katoh@st.seikei.ac.jp; Takada, Jitsuya . E-mail: takada@hl.rri.kyoto-u.ac.jp; Sakurai, Hiromu . E-mail: sakurai@mb.kyoto-phu.ac.jp

    2006-07-07

    Previously, we found that bis(allixinato)oxovanadium(IV) (VO(alx){sub 2}) exhibits a potent hypoglycemic activity in type 1-like diabetic mice. Since the enhancement of insulin sensitivity is involved in one of the mechanisms by which vanadium exerts its anti-diabetic effects, VO(alx){sub 2} was further tested in type 2 diabetes with low insulin sensitivity. The effect of oral administration of VO(alx){sub 2} was examined in obesity-linked type 2 diabetic KKA{sup y} mice. Treatment of VO(alx){sub 2} for 4 weeks normalized hyperglycemia, glucose intolerance, hyperinsulinemia, hypercholesterolemia and hypertension in KKA{sup y} mice; however, it had no effect on hypoadiponectinemia. VO(alx){sub 2} also improved hyperleptinemia, following attenuation of obesity in KKA{sup y} mice. This is the first example in which a vanadium compound improved leptin resistance in type 2 diabetes by oral administration. On the basis of these results, VO(alx){sub 2} is proposed to enhance not only insulin sensitivity but also leptin sensitivity, which in turn improves diabetes, obesity and hypertension in an obesity-linked type 2 diabetic animal.

  20. Conjugative type IV secretion in Gram-positive pathogens: TraG, a lytic transglycosylase and endopeptidase, interacts with translocation channel protein TraM.

    PubMed

    Kohler, Verena; Probst, Ines; Aufschnaiter, Andreas; Büttner, Sabrina; Schaden, Lisa; Rechberger, Gerald N; Koraimann, Günther; Grohmann, Elisabeth; Keller, Walter

    2017-02-17

    Conjugative transfer plays a major role in the transmission of antibiotic resistance in bacteria. pIP501 is a Gram-positive conjugative model plasmid with the broadest transfer host-range known so far and is frequently found in Enterococcus faecalis and Enterococcus faecium clinical isolates. The pIP501 type IV secretion system is encoded by 15 transfer genes. In this work, we focus on the VirB1-like protein TraG, a modular peptidoglycan metabolizing enzyme, and the VirB8-homolog TraM, a potential member of the translocation channel. By providing full-length traG in trans, but not with a truncated variant, we achieved full recovery of wild type transfer efficiency in the traG-knockout mutant E. faecalis pIP501ΔtraG. With peptidoglycan digestion experiments and tandem mass spectrometry we could assign lytic transglycosylase and endopeptidase activity to TraG, with the CHAP domain alone displaying endopeptidase activity. We identified a novel interaction between TraG and TraM in a bacterial-2-hybrid assay. In addition we found that both proteins localize in focal spots at the E. faecalis cell membrane using immunostaining and fluorescence microscopy. Extracellular protease digestion to evaluate protein cell surface exposure revealed that correct membrane localization of TraM requires the transmembrane helix of TraG. Thus, we suggest an essential role for TraG in the assembly of the pIP501 type IV secretion system.

  1. SDSS-IV MaNGA: Spatially resolved star formation histories in galaxies as a function of galaxy mass and type

    NASA Astrophysics Data System (ADS)

    Goddard, D.; Thomas, D.; Maraston, C.; Westfall, K.; Etherington, J.; Riffel, R.; Mallmann, N. D.; Zheng, Z.; Argudo-Fernández, M.; Lian, J.; Bershady, M.; Bundy, K.; Drory, N.; Law, D.; Yan, R.; Wake, D.; Weijmans, A.; Bizyaev, D.; Brownstein, J.; Lane, R. R.; Maiolino, R.; Masters, K.; Merrifield, M.; Nitschelm, C.; Pan, K.; Roman-Lopes, A.; Storchi-Bergmann, T.; Schneider, D. P.

    2016-12-01

    We study the internal gradients of stellar population properties within 1.5 Re for a representative sample of 721 galaxies with stellar masses ranging between 109 M⊙ to 1011.5 M⊙ from the SDSS-IV MaNGA IFU survey. Through the use of our full spectral fitting code FIREFLY, we derive light and mass-weighted stellar population properties and their radial gradients, as well as full star formation and metal enrichment histories. We also quanfify the impact that different stellar population models and full spectral fitting routines have on the derived stellar population properties, and the radial gradient measurements. In our analysis, we find that age gradients tend to be shallow for both early-type and late-type galaxies. Mass-weighted age gradients of early-types are positive (˜0.09 dex/Re) pointing to "outside-in" progression of star formation, while late-type galaxies have negative light-weighted age gradients (˜-0.11 dex/Re), suggesting an "inside-out" formation of discs. We detect negative metallicity gradients in both early and late-type galaxies, but these are significantly steeper in late-types, suggesting that radial dependence of chemical enrichment processes and the effect of gas inflow and metal transport are far more pronounced in discs. Metallicity gradients of both morphological classes correlate with galaxy mass, with negative metallicity gradients becoming steeper with increasing galaxy mass. The correlation with mass is stronger for late-type galaxies, with a slope of d(∇[Z/H])/d(log M) ˜ -0.2 ± 0.05 , compared to d(∇[Z/H])/d(log M) ˜ -0.05 ± 0.05 for early-types. This result suggests that the merger history plays a relatively small role in shaping metallicity gradients of galaxies.

  2. Icariin attenuates high glucose-induced type IV collagen and fibronectin accumulation in glomerular mesangial cells by inhibiting transforming growth factor-β production and signalling through G protein-coupled oestrogen receptor 1.

    PubMed

    Li, Yi-Chen; Ding, Xuan-Sheng; Li, Hui-Mei; Zhang, Cheng

    2013-09-01

    Icariin has been shown to attenuate diabetic nephropathy in rats by decreasing transforming growth factor-β (TGF-β) and type IV collagen expression, but its mode of action in glomerular mesangial cells is uncertain. The present study aimed to investigate the effect of icariin on excess mesangial type IV collagen and fibronectin accumulation induced by high glucose, and to determine the mechanism underlying its protective effects. Under high-glucose conditions, icariin diminished type IV collagen and fibronectin accumulation, as well as TGF-β production in human and rat mesangial cells. Mesangial cells treated with icariin after TGF-β1 exposure expressed less type IV collagen and fibronectin than those without icariin treatment, suggesting inhibition by icariin of TGF-β1 downstream pathways. On TGF-β1 stimulation, icariin inhibited TGF-β canonical Smad signalling and extracellular signal-regulated kinase (ERK)1/2 signalling by decreasing Smad2/3 and ERK1/2 phosphorylation in a dose-dependent manner. U0126, which blocked the ERK1/2 pathway, exerted an additive effect on the icariin suppression of type IV collagen and fibronectin expression, enhancing the beneficial effects of icariin. The G protein-coupled oestrogen receptor 1 (GPER) antagonist, G-15, abolished the icariin-induced inhibition of type IV collagen, and fibronectin overproduction and TGF-β signalling. Treatment of cells with fulvestrant, a downregulator of the oestrogen receptor, enhanced the action of icariin. In conclusion, icariin decreased type IV collagen and fibronectin accumulation induced by high glucose in mesangial cells by inhibiting TGF-β production, as well as Smad and ERK signalling in a GPER-dependent manner.

  3. IVS Organization

    NASA Technical Reports Server (NTRS)

    2004-01-01

    International VLBI Service (IVS) is an international collaboration of organizations which operate or support Very Long Baseline Interferometry (VLBI) components. The goals are: To provide a service to support geodetic, geophysical and astrometric research and operational activities. To promote research and development activities in all aspects of the geodetic and astrometric VLBI technique. To interact with the community of users of VLBI products and to integrate VLBI into a global Earth observing system.

  4. Sublattice enumeration. IV. Equivalence classes of plane sublattices by parent Patterson symmetry and colour lattice group type.

    PubMed

    Rutherford, John S

    2009-03-01

    The Dirichlet generating functions for the number of sublattices fixed under each symmetry operation of the parent Patterson group may be combined to count the number of crystallographically nonequivalent sublattices, in total, by sublattice point group and by colour lattice group type. The combinatorial formulae used imply the existence of various congruences among the corresponding arithmetic functions.

  5. Comparative analysis of basal lamina type IV collagen α chains, matrix metalloproteinases-2 and -9 expressions in oral dysplasia and invasive carcinoma.

    PubMed

    Tamamura, Ryo; Nagatsuka, Hitoshi; Siar, Chong Huat; Katase, Naoki; Naito, Ichiro; Sado, Yoshikazu; Nagai, Noriyuki

    2013-03-01

    The aim of this study was to compare the expressions of basal lamina (BL) collagen IV α chains and matrix metalloproteinases (MMP)-2 and MMP-9 in oral dysplasia (OED) and invasive carcinoma. Ten cases each of OEDs, carcinomas-in situ and oral squamous cell carcinomas (OSCCs) were examined by immunohistochemistry. Another 5 cases, each of normal and hyperplastic oral mucosa, served as controls. Results showed that α1(IV)/α2(IV) and α5(IV)/α6(IV) chains were intact in BLs of control and OEDs. In BLs of carcinoma-in situ, α1(IV)/α2(IV) chains preceded α5(IV)/α6(IV) chains in showing incipient signs of disruption. OSCCs exhibited varying degrees of collagen α(IV) chain degradation. MMP-2 and MMP-9 were absent in controls and OED, but weakly detectable in carcinoma-in situ. In OSCC, these proteolytic enzymes were expressed in areas corresponding to collagen α(IV) chain loss. Enzymatic activity was enhanced in higher grade OSCC, and along the tumor advancing front. Overall the present findings suggest that loss of BL collagen α(IV) chains coincided with gain of expression for MMP-2 and MMP-9, and that these protein alterations are crucial events during progression from OED to OSCC.

  6. Structures of acetylated oleanane-type triterpene saponins, rarasaponins IV, V, and VI, and anti-hyperlipidemic constituents from the pericarps of Sapindus rarak.

    PubMed

    Asao, Yasunobu; Morikawa, Toshio; Xie, Yuanyuan; Okamoto, Masaki; Hamao, Makoto; Matsuda, Hisashi; Muraoka, Osamu; Yuan, Dan; Yoshikawa, Masayuki

    2009-02-01

    The methanolic extract and its saponin fraction (methanol-eluted fraction) of the pericarps of Sapindus rarak DC. were found to suppress plasma triglyceride elevation in olive oil-treated mice. From the active fraction, three new acylated oleanane-type triterpene saponins, rarasaponins IV (1), V (2), and VI (3), were isolated. The structures of 1-3 were elucidated on the basis of chemical and spectroscopic evidence. The principle saponin constituents, hederagenin 3-O-alpha-L-arabinopyranosyl-(1-->3)-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranoside (4) and hederagenin 3-O-(3,4-di-O-acetyl-alpha-L-arabinopyranosyl)-(1-->3)-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranoside (5), showed inhibitory effects on plasma triglyceride elevation at a dose of 200 mg/kg, per os.

  7. Bryan and Morrey type IV intra-articular fracture of the distal extremity of the humerus treated surgically with anterior access: case report.

    PubMed

    Dressler, Hugo Bertani; de Paula, Ricardo Nunes Borges

    2015-01-01

    Within the context of elbow-level trauma, fractures with a coronal line at the distal extremity of the humerus are rare and result from indirect axial trauma with the arm extended. These are difficult-to-treat intra-articular fractures, since they require stable anatomical reduction in order to maintain joint congruence and diminish complications such as stiffness. This paper reports a case that occurred in a young man who suffered a fall from a ladder that resulted in a Bryan and Morrey type IV intra-articular fracture of the humerus. The injury was treated surgically by means of an anterior access, using osteosynthesis with two Herbert screws that were inserted from anterior to posterior.

  8. Immuno-localization of type-IV collagen in the blood-gas barrier and the epithelial–epithelial cell connections of the avian lung

    PubMed Central

    Jimoh, S. A.; Maina, J. N.

    2013-01-01

    The terminal respiratory units of the gas exchange tissue of the avian lung, the air capillaries (ACs) and the blood capillaries (BCs), are small and rigid: the basis of this mechanical feature has been highly contentious. Because the strength of the blood-gas barrier (BGB) of the mammalian lung has been attributed to the presence of type-IV collagen (T-IVc), localization of T-IVc in the basement membranes (BM) of the BGB and the epithelial–epithelial cell connections (E-ECCs) of the exchange tissue of the lung of the avian (chicken) lung was performed in order to determine whether it may likewise contribute to the strength of the BGB. T-IVc was localized in both the BM and the E-ECCs. As part of an integrated fibroskeletal scaffold on the lung, T-IVc may directly contribute to the strengths of the ACs and the BCs. PMID:23193049

  9. Steered molecular dynamics simulations of a bacterial type IV pilus reveal characteristics of an experimentally-observed, force-induced conformational transition

    NASA Astrophysics Data System (ADS)

    Baker, Joseph; Biais, Nicolas; Tama, Florence

    2011-10-01

    Type IV pili (T4P) are long, filamentous structures that emanate from the cellular surface of many infectious bacteria. They are built from a 158 amino acid long subunit called pilin. T4P can grow to many micrometers in length, and can withstand large tension forces. During the infection process, pili attach themselves to host cells, and therefore naturally find themselves under tension. We investigated the response of a T4 pilus to a pulling force using the method of steered molecular dynamics (SMD) simulation. Our simulations expose to the external environment an amino acid sequence initially hidden in the native filament, in agreement with experimental data. Therefore, our simulations might be probing the initial stage of the transition to a force-induced conformation of the T4 pilus. Additional exposed amino acid sequences that might be useful targets for drugs designed to mitigate bacterial infection were also predicted.

  10. Postreplication Roles of the Brucella VirB Type IV Secretion System Uncovered via Conditional Expression of the VirB11 ATPase

    PubMed Central

    Smith, Erin P.; Miller, Cheryl N.; Child, Robert; Cundiff, Jennifer A.

    2016-01-01

    ABSTRACT Brucella abortus, the bacterial agent of the worldwide zoonosis brucellosis, primarily infects host phagocytes, where it undergoes an intracellular cycle within a dedicated membrane-bound vacuole, the Brucella-containing vacuole (BCV). Initially of endosomal origin (eBCV), BCVs are remodeled into replication-permissive organelles (rBCV) derived from the host endoplasmic reticulum, a process that requires modulation of host secretory functions via delivery of effector proteins by the Brucella VirB type IV secretion system (T4SS). Following replication, rBCVs are converted into autophagic vacuoles (aBCVs) that facilitate bacterial egress and subsequent infections, arguing that the bacterium sequentially manipulates multiple cellular pathways to complete its cycle. The VirB T4SS is essential for rBCV biogenesis, as VirB-deficient mutants are stalled in eBCVs and cannot mediate rBCV biogenesis. This has precluded analysis of whether the VirB apparatus also drives subsequent stages of the Brucella intracellular cycle. To address this issue, we have generated a B. abortus strain in which VirB T4SS function is conditionally controlled via anhydrotetracycline (ATc)-dependent complementation of a deletion of the virB11 gene encoding the VirB11 ATPase. We show in murine bone marrow-derived macrophages (BMMs) that early VirB production is essential for optimal rBCV biogenesis and bacterial replication. Transient expression of virB11 prior to infection was sufficient to mediate normal rBCV biogenesis and bacterial replication but led to T4SS inactivation and decreased aBCV formation and bacterial release, indicating that these postreplication stages are also T4SS dependent. Hence, our findings support the hypothesis of additional, postreplication roles of type IV secretion in the Brucella intracellular cycle. PMID:27899503

  11. A Component of the Xanthomonadaceae Type IV Secretion System Combines a VirB7 Motif with a N0 Domain Found in Outer Membrane Transport Proteins

    PubMed Central

    Souza, Diorge P.; Andrade, Maxuel O.; Alvarez-Martinez, Cristina E.; Arantes, Guilherme M.; Farah, Chuck S.; Salinas, Roberto K.

    2011-01-01

    Type IV secretion systems (T4SS) are used by Gram-negative bacteria to translocate protein and DNA substrates across the cell envelope and into target cells. Translocation across the outer membrane is achieved via a ringed tetradecameric outer membrane complex made up of a small VirB7 lipoprotein (normally 30 to 45 residues in the mature form) and the C-terminal domains of the VirB9 and VirB10 subunits. Several species from the genera of Xanthomonas phytopathogens possess an uncharacterized type IV secretion system with some distinguishing features, one of which is an unusually large VirB7 subunit (118 residues in the mature form). Here, we report the NMR and 1.0 Å X-ray structures of the VirB7 subunit from Xanthomonas citri subsp. citri (VirB7XAC2622) and its interaction with VirB9. NMR solution studies show that residues 27–41 of the disordered flexible N-terminal region of VirB7XAC2622 interact specifically with the VirB9 C-terminal domain, resulting in a significant reduction in the conformational freedom of both regions. VirB7XAC2622 has a unique C-terminal domain whose topology is strikingly similar to that of N0 domains found in proteins from different systems involved in transport across the bacterial outer membrane. We show that VirB7XAC2622 oligomerizes through interactions involving conserved residues in the N0 domain and residues 42–49 within the flexible N-terminal region and that these homotropic interactions can persist in the presence of heterotropic interactions with VirB9. Finally, we propose that VirB7XAC2622 oligomerization is compatible with the core complex structure in a manner such that the N0 domains form an extra layer on the perimeter of the tetradecameric ring. PMID:21589901

  12. DNA vaccine encoding type IV pilin of Actinobacillus pleuropneumoniae induces strong immune response but confers limited protective efficacy against serotype 2 challenge.

    PubMed

    Lu, Yu-Chun; Li, Min-Chen; Chen, Yi-Min; Chu, Chun-Yen; Lin, Shuen-Fuh; Yang, Wen-Jen

    2011-10-13

    Actinobacillus pleuropneumoniae is a gram-negative bacterial pathogen that causes swine pleuropneumonia, a highly contagious and often fatal disease that occurs worldwide. Our previous study showed that DNA vaccines encoding Apx exotoxin structural proteins ApxIA and/or ApxIIA, are a promising novel approach for immunization against the lethal challenge of A. pleuropneumoniae serotype 1. Vaccination against A. pleuropneumoniae is impeded by the lack of vaccines inducing reliable cross-serotype protection. Type IV fimbrial protein ApfA has been shown to be present and highly conserved in various serotypes of A. pleuropneumoniae. A novel DNA vaccine encoding ApfA (pcDNA-apfA) was constructed to evaluate the protective efficacy against infection with A. pleuropneumoniae serotype 2. A significant antibody response against pilin was generated following pcDNA-apfA immunization, suggesting that it was expressed in vivo. The IgG subclass (IgG1 and IgG2a) analysis indicates that the pcDNA-apfA vaccine induces both Th1 and Th2 immune responses. The IgA analysis shows that mucosal immunity could be enhanced by this DNA vaccine. Nevertheless, the strong antibody response induced by pcDNA-apfA vaccine only provided limited 30% protective efficacy against the serotype 2 challenge. These results in this study do not coincide with that the utility of type IV pilin is a good vaccine candidate against other infectious pathogens. It indicates that pilin should play a limited role in the development of a vaccine against A. pleuropneumoniae infection.

  13. Theory of chemical bonds in metalloenzymes IV: Hybrid-DFT study of Rieske-type [2Fe bond 2S] clusters

    NASA Astrophysics Data System (ADS)

    Shoji, Mitsuo; Koizumi, Kenichi; Kitagawa, Yasutaka; Yamanaka, Shusuke; Okumura, Mitsutaka; Yamaguchi, Kizashi

    The Rieske-type [2Fe bond 2S] cores of electron-transfer (ET) proteins in the mitochondrial respiratory chain have unusual properties, such as redox potentials and spectroscopy. In this study, part IV of a series, the inherent molecular structures and characteristic electronic structures of the Rieske-type [2Fe bond 2S] clusters are investigated using broken-symmetry hybrid density functional theory (BS-HDFT). Geometry optimizations for the oxidized and reduced states were performed and their characteristic vibrational modes are assigned. Magnetic properties are investigated using model Hamiltonians to describe the electron delocalization and the unsymmetric property. The parameters of the model Hamiltonian, such as exchange coupling J, valence delocalization B, and potential energy difference ?, are evaluated from the BS-HDFT calculations. The valence localization and excitation energy (?E) of the Rieske-type [2Fe bond 2S] cluster are discussed. The chemical bond nature is characterized by chemical indices from natural orbital analysis. Our theoretical results are reasonably consistent with experimental results.

  14. SecretEPDB: a comprehensive web-based resource for secreted effector proteins of the bacterial types III, IV and VI secretion systems

    PubMed Central

    An, Yi; Wang, Jiawei; Li, Chen; Revote, Jerico; Zhang, Yang; Naderer, Thomas; Hayashida, Morihiro; Akutsu, Tatsuya; Webb, Geoffrey I.; Lithgow, Trevor; Song, Jiangning

    2017-01-01

    Bacteria translocate effector molecules to host cells through highly evolved secretion systems. By definition, the function of these effector proteins is to manipulate host cell biology and the sequence, structural and functional annotations of these effector proteins will provide a better understanding of how bacterial secretion systems promote bacterial survival and virulence. Here we developed a knowledgebase, termed SecretEPDB (Bacterial Secreted Effector Protein DataBase), for effector proteins of type III secretion system (T3SS), type IV secretion system (T4SS) and type VI secretion system (T6SS). SecretEPDB provides enriched annotations of the aforementioned three classes of effector proteins by manually extracting and integrating structural and functional information from currently available databases and the literature. The database is conservative and strictly curated to ensure that every effector protein entry is supported by experimental evidence that demonstrates it is secreted by a T3SS, T4SS or T6SS. The annotations of effector proteins documented in SecretEPDB are provided in terms of protein characteristics, protein function, protein secondary structure, Pfam domains, metabolic pathway and evolutionary details. It is our hope that this integrated knowledgebase will serve as a useful resource for biological investigation and the generation of new hypotheses for research efforts aimed at bacterial secretion systems. PMID:28112271

  15. Parental somatic and germ-line mosaicism for a multiexon deletion with unusual endpoints in a type III collagen (COL3A1) allele produces Ehlers-Danlos syndrome type IV in the heterozygous offspring.

    PubMed Central

    Milewicz, D M; Witz, A M; Smith, A C; Manchester, D K; Waldstein, G; Byers, P H

    1993-01-01

    Ehlers-Danlos syndrome (EDS) type IV is a dominantly inherited disorder that results from mutations in the type III collagen gene (COL3A1). We studied the structure of the COL3A1 gene of an individual with EDS type IV and that of her phenotypically normal parents. The proband was heterozygous for a 2-kb deletion in COL3A1, while her father was mosaic for the same deletion in somatic and germ cells. In fibroblasts from the father, approximately two-fifths of the COL3A1 alleles carried the deletion, but only 10% of the COL3A1 alleles in white blood cells were of the mutant species. The deletion in the mutant allele extended from intron 7 into intron 11. There was a 12-bp direct repeat in intron 7 and intron 11, the latter about 60 bp 5' to the junction. At the breakpoint there was a duplication of 10 bp from intron 11 separated by an insertion of 4 bp contained within the duplicated sequence. The father was mosaic for the deletion so that the gene rearrangement occurred during his early embryonic development prior to lineage allocation. These findings suggest that at least some of the deletions seen in human genes may occur during replication, rather than as a consequence of meiotic crossing-over, and that they thus have a risk for recurrence when observed de novo. Images Figure 1 Figure 2 Figure 3 PMID:8317500

  16. Parental somatic and germ-line mosaicism for a multiexon deletion with unusual endpoints in a type III collagen (COL3Al) allele produces ehlers-danlos syndrome type IV in the heterozygous offspring

    SciTech Connect

    McGookey Milewicz, D.; Witz, A.M.; Byers, P.H. ); Smith, A.C.M.; Manchester, D.K.; Waldstein, G. )

    1993-07-01

    Ehlers-Danlos syndrome (EDS) type IV is a dominantly inherited disorder that results from mutation in the type III collagen gene (COL3A1). The authors studied the structure of the COL3A1 gene of an individual with EDS type IV and that of her phenotypically normal parents. The proband was heterozygous for a 2-kb deletion in COL3A1, while her father was mosaic for the same deletion in somatic and germ cells. In fibroblasts from the father, approximately two-fifths of the COL3A1 alleles carried the deletion, but only 10% of the COL3A1 alleles in white blood cells were of the mutant species. The deletion in the mutant allele extended from intron 7 into intron 11. There was a 12-bp direct repeat in intron 7 and intron 11, the latter about 60 bp 5' to the junction. At the breakpoint there was a duplication of 10 bp from intron 11 separated by an insertion of 4 bp contained within the duplicated sequence. The father was mosaic for the deletion so that the gene rearrangement occurred during his early embryonic development prior to lineage allocation. These findings suggest that at least some of the deletions seen in human genes may occur during replication, rather than as a consequence of meiotic crossing-over, and that they thus have a risk for recurrence when observed de novo. 71 refs., 4 figs., 2 tabs.

  17. SDSS-IV MaNGA: Variation of the Stellar Initial Mass Function in Spiral and Early-type Galaxies

    NASA Astrophysics Data System (ADS)

    Li, Hongyu; Ge, Junqiang; Mao, Shude; Cappellari, Michele; Long, R. J.; Li, Ran; Emsellem, Eric; Dutton, Aaron A.; Li, Cheng; Bundy, Kevin; Thomas, Daniel; Drory, Niv; Lopes, Alexandre Roman

    2017-04-01

    We perform Jeans anisotropic modeling (JAM) on elliptical and spiral galaxies from the MaNGA DR13 sample. By comparing the stellar mass-to-light ratios estimated from stellar population synthesis and from JAM, we find a systematic variation of the initial mass function (IMF) similar to that in the earlier {{ATLAS}}3{{D}} results. Early-type galaxies (elliptical and lenticular) with lower velocity dispersions within one effective radius are consistent with a Chabrier-like IMF, while galaxies with higher velocity dispersions are consistent with a more bottom-heavy IMF such as the Salpeter IMF. Spiral galaxies have similar systematic IMF variations, but with slightly different slopes and larger scatters, due to the uncertainties caused by the higher gas fractions and extinctions for these galaxies. Furthermore, we examine the effects of stellar mass-to-light ratio gradients on our JAM modeling, and we find that the trends become stronger after considering the gradients.

  18. Early Diagnosis and Treatment of Coronary Heart Disease in Symptomatic Subjects With Advanced Vascular Atherosclerosis of the Carotid Artery (Type III and IV b Findings Using Ultrasound)

    PubMed Central

    Adams, Ansgar; Bojara, Waldemar; Schunk, Klaus

    2017-01-01

    Background A study was conducted as to whether the early diagnosis of coronary heart disease (CHD) in symptomatic patients with advanced atherosclerosis of the carotid artery was more successful using ultrasound technology than exercise electrocardiography (ECG). Methods Within the scope of an occupational screening program using subjects from diverse employment sectors, people were given the opportunity to determine their risk of heart attack. During the study, the total plaque area (TPA), the maximum plaque thickness in the carotid artery and the PROCAM scores of 3,513 healthy men and 2,088 healthy women between the ages of 20 and 65 were determined. During the subsequent follow-up study, 36 subjects developed symptoms such as exertional dyspnea, atypical angina pectoris (AP) or typical AP. Four patients displayed no symptoms. The initial cardiac diagnostic testing was conducted on 31 patients using an exercise ECG, four patients were assessed using a coronary angiogram, and five further patients were assessed using a computed tomography (CT) coronary angiogram. An ultrasound examination of the carotid artery of 39 patients revealed a type IV b finding and in one patient, the examination revealed a type III finding. Results In 17 patients, the PROCAM score was < 10%, 13 patients had a score of 10-20% and 10 patients had a score of > 20%. In the final analysis, only two patients had entirely smooth coronary arteries, seven had coronary sclerosis, seven had a 30% stenosis, one had a 30-40% stenosis, one had a 40% stenosis, and 22 patients had a stenosis ≥ 50%, and in extreme cases, a left main coronary artery stenosis with three-vessel disease was shown. The exercise ECG only achieved a true positive result in four patients, and in 21 patients, the result was false negative. Conclusions Symptomatic patients with advanced atherosclerosis of the carotid artery (type III and type IV b findings) had a high risk for CHD. The diagnosis of CHD is better achieved by

  19. Identification of Coxiella burnetii type IV secretion substrates required for intracellular replication and Coxiella-containing vacuole formation.

    PubMed

    Weber, Mary M; Chen, Chen; Rowin, Kristina; Mertens, Katja; Galvan, Gloria; Zhi, Hui; Dealing, Christopher M; Roman, Victor A; Banga, Simran; Tan, Yunhao; Luo, Zhao-Qing; Samuel, James E

    2013-09-01

    Coxiella burnetii, the etiological agent of acute and chronic Q fever in humans, is a naturally intracellular pathogen that directs the formation of an acidic Coxiella-containing vacuole (CCV) derived from the host lysosomal network. Central to its pathogenesis is a specialized type IVB secretion system (T4SS) that delivers effectors essential for intracellular replication and CCV formation. Using a bioinformatics-guided approach, 234 T4SS candidate substrates were identified. Expression of each candidate as a TEM-1 β-lactamase fusion protein led to the identification of 53 substrates that were translocated in a Dot/Icm-dependent manner. Ectopic expression in HeLa cells revealed that these substrates trafficked to distinct subcellular sites, including the endoplasmic reticulum, mitochondrion, and nucleus. Expression in Saccharomyces cerevisiae identified several substrates that were capable of interfering with yeast growth, suggesting that these substrates target crucial host processes. To determine if any of these T4SS substrates are necessary for intracellular replication, we isolated 20 clonal T4SS substrate mutants using the Himar1 transposon and transposase. Among these, 10 mutants exhibited defects in intracellular growth and CCV formation in HeLa and J774A.1 cells but displayed normal growth in bacteriological medium. Collectively, these results indicate that C. burnetii encodes a large repertoire of T4SS substrates that play integral roles in host cell subversion and CCV formation and suggest less redundancy in effector function than has been found in the comparative Legionella Dot/Icm model.

  20. A Unified Strategy toward the Synthesis of Acerogenin-Type Macrocycles: Total Syntheses of Acerogenins A, B, C, and L and Aceroside IV.

    PubMed

    Gonzalez, Gabriela Islas; Zhu, Jieping

    1999-02-05

    A general strategy for the synthesis of acerogenin-type diarylheptanoids containing an endocyclic biaryl ether bond has been developed, and convergent total syntheses of acerogenin A, B, C, and L and aceroside IV have been accomplished. Cycloetherification of the linear diarylheptanoid 1-(4-fluoro-3-nitrophenyl)-7-(3-hydroxy-4-methoxyphenyl)heptan-3-one (18) under mild conditions (CsF, DMF, 0.01 M, rt, 5 h) gave the macrocycle 4-methoxy-17-nitro-2-oxatricyclo[13.2.2(3,7)]eicosa-1(18),3,5,7(20),15(19),16-hexaen-12-one (19) in 95% yield. Removal of the nitro group followed by O-demethylation gave acerogenin C (2), whose reduction afforded acerogenin A (1). Glucosidation of 2 with 2,3,4,6-alpha-D-tetrabenzoylglucopyranosyl bromide followed by saponification gave aceroside IV (3) in excellent overall yield. Acerogenins B (4) and L (5) were synthesized in a similar fashion featuring a key intramolecular S(N)Ar reaction of linear compound 29. The entropy driving force resulting from the preorganization of cyclization precursors in favor of the bent conformation was proposed to contribute significantly to the efficiency of this cyclization. Both computational studies and spectroscopic data (NOE) supported this hypothesis. Experimentally, it was observed that even at high concentration (1 M of 18 in DMF) the analytically pure macrocycle 19 could still be obtained in 45-50% isolated yield. Furthermore, when the cyclization of 18 was carried out in the presence of an external nucleophile (4-methoxyphenol, 33) or an electrophile (4-fluoro-3-nitrotoluene, 34), only the 15-membered cyclophane 19 was isolable. This provides experimental evidence that compound 18 is indeed preorganized in such a way that intramolecular reaction was highly competitive with the alternative intermolecular process.

  1. Chimeric Coupling Proteins Mediate Transfer of Heterologous Type IV Effectors through the Escherichia coli pKM101-Encoded Conjugation Machine

    PubMed Central

    Whitaker, Neal; Berry, Trista M.; Rosenthal, Nathan; Gordon, Jay E.; Gonzalez-Rivera, Christian; Sheehan, Kathy B.; Truchan, Hilary K.; VieBrock, Lauren; Newton, Irene L. G.; Carlyon, Jason A.

    2016-01-01

    ABSTRACT Bacterial type IV secretion systems (T4SSs) are composed of two major subfamilies, conjugation machines dedicated to DNA transfer and effector translocators for protein transfer. We show here that the Escherichia coli pKM101-encoded conjugation system, coupled with chimeric substrate receptors, can be repurposed for transfer of heterologous effector proteins. The chimeric receptors were composed of the N-terminal transmembrane domain of pKM101-encoded TraJ fused to soluble domains of VirD4 homologs functioning in Agrobacterium tumefaciens, Anaplasma phagocytophilum, or Wolbachia pipientis. A chimeric receptor assembled from A. tumefaciens VirD4 (VirD4At) mediated transfer of a MOBQ plasmid (pML122) and A. tumefaciens effector proteins (VirE2, VirE3, and VirF) through the pKM101 transfer channel. Equivalent chimeric receptors assembled from the rickettsial VirD4 homologs similarly supported the transfer of known or candidate effectors from rickettsial species. These findings establish a proof of principle for use of the dedicated pKM101 conjugation channel, coupled with chimeric substrate receptors, to screen for translocation competency of protein effectors from recalcitrant species. Many T4SS receptors carry sequence-variable C-terminal domains (CTDs) with unknown function. While VirD4At and the TraJ/VirD4At chimera with their CTDs deleted supported pML122 transfer at wild-type levels, ΔCTD variants supported transfer of protein substrates at strongly diminished or elevated levels. We were unable to detect binding of VirD4At's CTD to the VirE2 effector, although other VirD4At domains bound this substrate in vitro. We propose that CTDs evolved to govern the dynamics of substrate presentation to the T4SS either through transient substrate contacts or by controlling substrate access to other receptor domains. IMPORTANCE Bacterial type IV secretion systems (T4SSs) display striking versatility in their capacity to translocate DNA and protein substrates to

  2. Studying Coxiella burnetii Type IV Substrates in the Yeast Saccharomyces cerevisiae: Focus on Subcellular Localization and Protein Aggregation

    PubMed Central

    Rodríguez-Escudero, María; Cid, Víctor J.; Molina, María; Schulze-Luehrmann, Jan; Lührmann, Anja; Rodríguez-Escudero, Isabel

    2016-01-01

    Coxiella burnetii is a Gram-negative obligate parasitic bacterium that causes the disease Q-fever in humans. To establish its intracellular niche, it utilizes the Icm/Dot type IVB secretion system (T4BSS) to inject protein effectors into the host cell cytoplasm. The host targets of most cognate and candidate T4BSS-translocated effectors remain obscure. We used the yeast Saccharomyces cerevisiae as a model to express and study six C. burnetii effectors, namely AnkA, AnkB, AnkF, CBU0077, CaeA and CaeB, in search for clues about their role in C. burnetii virulence. When ectopically expressed in HeLa cells, these effectors displayed distinct subcellular localizations. Accordingly, GFP fusions of these proteins produced in yeast also decorated distinct compartments, and most of them altered cell growth. CaeA was ubiquitinated both in yeast and mammalian cells and, in S. cerevisiae, accumulated at juxtanuclear quality-control compartments (JUNQs) and insoluble protein deposits (IPODs), characteristic of aggregative or misfolded proteins. AnkA, which was not ubiquitinated, accumulated exclusively at the IPOD. CaeA, but not AnkA or the other effectors, caused oxidative damage in yeast. We discuss that CaeA and AnkA behavior in yeast may rather reflect misfolding than recognition of conserved targets in the heterologous system. In contrast, CBU0077 accumulated at vacuolar membranes and abnormal ER extensions, suggesting that it interferes with vesicular traffic, whereas AnkB associated with the yeast nucleolus. Both effectors shared common localization features in HeLa and yeast cells. Our results support the idea that C. burnetii T4BSS effectors manipulate multiple host cell targets, which can be conserved in higher and lower eukaryotic cells. However, the behavior of CaeA and AnkA prompt us to conclude that heterologous protein aggregation and proteostatic stress can be a limitation to be considered when using the yeast model to assess the function of bacterial effectors

  3. Berkeley Supernova Ia Program - IV. Carbon detection in early-time optical spectra of Type Ia supernovae

    NASA Astrophysics Data System (ADS)

    Silverman, Jeffrey M.; Filippenko, Alexei V.

    2012-09-01

    While O is often seen in spectra of Type Ia supernovae (SNe Ia) as both unburned fuel and a product of C burning, C is only occasionally seen at the earliest times and represents the most direct way of investigating primordial white dwarf material and its relation to SN Ia explosion scenarios and mechanisms. In this paper, we search for C absorption features in 188 optical spectra of 144 low-redshift (z < 0.1) SNe Ia with ages ≲3.6 d after maximum brightness. These data were obtained as part of the Berkeley Supernova Ia Program (BSNIP) and represent the largest set of SNe Ia in which C has ever been searched. We find that ˜11 per cent of the SNe studied show definite C absorption features, while ˜25 per cent show some evidence for C II in their spectra. Also, if one obtains a spectrum at ≲ -5 d, then there is a better than 30 per cent chance of detecting a distinct absorption feature from C II. SNe Ia that show C are found to resemble those without C in many respects, but objects with C tend to have bluer optical colours than those without C. The typical expansion velocity of the C II λ6580 feature is measured to be 12 000-13 000 km s-1, and the ratio of the C II λ6580 to Si II λ6355 velocities is remarkably constant with time and among different objects with a median value of ˜1.05. While the pseudo-equivalent widths (pEWs) of the C II λλ6580 and 7234 features are found mostly to decrease with time, we see evidence of a significant increase in pEW between ˜12 and 11 d before maximum brightness, which is actually predicted by some theoretical models. The range of pEWs measured from the BSNIP data implies a range of C masses in SN Ia ejecta of about (2-30) × 10-3 M⊙.

  4. Studying Coxiella burnetii Type IV Substrates in the Yeast Saccharomyces cerevisiae: Focus on Subcellular Localization and Protein Aggregation.

    PubMed

    Rodríguez-Escudero, María; Cid, Víctor J; Molina, María; Schulze-Luehrmann, Jan; Lührmann, Anja; Rodríguez-Escudero, Isabel

    2016-01-01

    Coxiella burnetii is a Gram-negative obligate parasitic bacterium that causes the disease Q-fever in humans. To establish its intracellular niche, it utilizes the Icm/Dot type IVB secretion system (T4BSS) to inject protein effectors into the host cell cytoplasm. The host targets of most cognate and candidate T4BSS-translocated effectors remain obscure. We used the yeast Saccharomyces cerevisiae as a model to express and study six C. burnetii effectors, namely AnkA, AnkB, AnkF, CBU0077, CaeA and CaeB, in search for clues about their role in C. burnetii virulence. When ectopically expressed in HeLa cells, these effectors displayed distinct subcellular localizations. Accordingly, GFP fusions of these proteins produced in yeast also decorated distinct compartments, and most of them altered cell growth. CaeA was ubiquitinated both in yeast and mammalian cells and, in S. cerevisiae, accumulated at juxtanuclear quality-control compartments (JUNQs) and insoluble protein deposits (IPODs), characteristic of aggregative or misfolded proteins. AnkA, which was not ubiquitinated, accumulated exclusively at the IPOD. CaeA, but not AnkA or the other effectors, caused oxidative damage in yeast. We discuss that CaeA and AnkA behavior in yeast may rather reflect misfolding than recognition of conserved targets in the heterologous system. In contrast, CBU0077 accumulated at vacuolar membranes and abnormal ER extensions, suggesting that it interferes with vesicular traffic, whereas AnkB associated with the yeast nucleolus. Both effectors shared common localization features in HeLa and yeast cells. Our results support the idea that C. burnetii T4BSS effectors manipulate multiple host cell targets, which can be conserved in higher and lower eukaryotic cells. However, the behavior of CaeA and AnkA prompt us to conclude that heterologous protein aggregation and proteostatic stress can be a limitation to be considered when using the yeast model to assess the function of bacterial effectors.

  5. TraK and TraB are conserved outer membrane proteins of the Neisseria gonorrhoeae Type IV secretion system and are expressed at low levels in wild-type cells.

    PubMed

    Ramsey, Meghan E; Hackett, Kathleen T; Bender, Tobias; Kotha, Chaitra; van der Does, Chris; Dillard, Joseph P

    2014-08-15

    Neisseria gonorrhoeae uses a type IV secretion system (T4SS) to secrete chromosomal DNA into the medium, and this DNA is effective in transforming other gonococci via natural transformation. In addition, the T4SS is important in the initial stages of biofilm development and mediates intracellular iron uptake in the absence of TonB. To better understand the mechanism of type IV secretion in N. gonorrhoeae, we examined the expression levels and localization of two predicted T4SS outer membrane proteins, TraK and TraB, in the wild-type strain as well as in overexpression strains and in a strain lacking all of the T4SS proteins. Despite very low sequence similarity to known homologues, TraB (VirB10 homolog) and TraK (VirB9 homolog) localized similarly to related proteins in other systems. Additionally, we found that TraV (a VirB7 homolog) interacts with TraK, as in other T4SSs. However, unlike in other systems, neither TraK nor TraB required the presence of other T4SS components for proper localization. Unlike other gonococcal T4SS proteins we have investigated, protein levels of the outer membrane proteins TraK and TraB were extremely low in wild-type cells and were undetectable by Western blotting unless overexpressed or tagged with a FLAG3 triple-epitope tag. Localization of TraK-FLAG3 in otherwise wild-type cells using immunogold electron microscopy of thin sections revealed a single gold particle on some cells. These results suggest that the gonococcal T4SS may be present in single copy per cell and that small amounts of T4SS proteins TraK and TraB are sufficient for DNA secretion.

  6. A case of subepidermal blistering disease with autoantibodies to multiple laminin subunits who developed later autoantibodies to alpha-5 chain of type IV collagen associated with membranous glomerulonephropathy.

    PubMed

    Sueki, Hirohiko; Sato, Yoshinori; Ohtoshi, Shinpei; Nakada, Tokio; Yoshimura, Ashio; Tateishi, Chiharu; Borza, Dorin-Bogdan; Fader, William; Ghohestani, Reza F; Hirako, Yoshiaki; Koga, Hiroshi; Ishii, Norito; Tsuchisaka, Atsunari; Qian, Hua; Li, Xiaoguang; Hashimoto, Takashi

    2015-09-01

    We report a 68-year-old Japanese female patient with subepidermal blistering disease with autoantibodies to multiple laminins, who subsequently developed membranous glomerulonephropathy. At skin disease stage, immunofluorescence demonstrated IgG anti-basement membrane zone antibodies reactive with dermal side of NaCl-split skin. Immunoblotting of human dermal extract, purified laminin-332, hemidesmosome-rich fraction and laminin-521 trimer recombinant protein (RP) detected laminin γ-1 and α-3 and γ-2 subunits of laminin-332. Three years after skin lesions disappeared, nephrotic symptoms developed. Antibodies to α-3 chain of type IV collagen (COL4A3) were negative, thus excluding the diagnosis of Goodpasture syndrome. All anti-laminin antibodies disappeared. Additional IB and ELISA studies of RPs of various COL4 chains revealed reactivity with COL4A5, but not with COL4A6 or COL4A3. Although diagnosis of anti-laminin γ-1 (p200) pemphigoid or anti-laminin-332-type mucous membrane pemphigoid could not be made, this case was similar to previous cases with autoantibodies to COL4A5 and/or COL4A6.

  7. Concomitant neoplasms in the skin and stomach unveil the role of type IV collagen and E-cadherin in mucin core protein 5AC expression in vivo.

    PubMed

    Hata, H; Natsuga, K; Kitamura, S; Imafuku, K; Yamaguchi, Y; Ebihara, Y; Shichinohe, T; Hirano, S; Shimizu, H

    2016-02-01

    Mucin core protein (MUC) 5AC is a gel-forming glycoprotein that is expressed in different types of tumour cells. MUC5AC expression in cultured cells is regulated through the extracellular matrix and through remodelling by other membranous proteins such as type IV collagen (COL4) and E-cadherin. However, it has not been elucidated whether COL4 and E-cadherin affect MUC5AC expression in tumours in vivo. Here, by analysing a single individual with concomitant neoplasms in the skin [extramammary Paget disease (EMPD)] and the stomach (gastric cancer), we show that MUC5AC expression is reduced in COL4 and membranous E-cadherin-expressing EMPD specimens whereas MUC5AC is not abolished in gastric cancer with COL4 negativity and E-cadherin cytoplasmic localization. As the EMPD and gastric cancer specimens were derived from a single patient, each specimen had the same genetic background. These in vivo results support previous in vitro studies which showed that COL4 and E-cadherin downregulated MUC5AC expression. Our study suggests that concomitant neoplasms in different organs of the same individual can serve as a strong tool for uncovering functional diversity in tumour markers in distinct cancer cells.

  8. Crystal Structure of a Type IV Pilus Assembly ATPase: Insights into the Molecular Mechanism of PilB from Thermus thermophilus

    DOE PAGES

    Mancl, Jordan M.; Black, Wesley P.; Robinson, Howard; ...

    2016-09-22

    Type IV pili (T4P) mediate bacterial motility and virulence. The PilB/GspE family ATPases power the assembly of T4P and type 2 secretion systems. We determined the structure of the ATPase region of PilB (PilBATP) in complex with ATPγS to provide a model of a T4P assembly ATPase and a view of a PilB/GspE family hexamer at better than 3-Å resolution. Spatial positioning and conformations of the protomers suggest a mechanism of force generation. All six PilBATP protomers contain bound ATPγS. Two protomers form a closed conformation poised for ATP hydrolysis. The other four molecules assume an open conformation but separatemore » into two pairs with distinct active-site accessibilities. We propose that one pair represents the post-hydrolysis phase while the other pair appears poised for ADP/ATP exchange. In conclusion, collectively, the data suggest that T4P assembly is powered by coordinating concurrent substrate binding with ATP hydrolysis across the PilB hexamer.« less

  9. Novel plasmid and its variant harboring both a bla(NDM-1) gene and type IV secretion system in clinical isolates of Acinetobacter lwoffii.

    PubMed

    Hu, Hongyan; Hu, Yongfei; Pan, Yuanlong; Liang, Hui; Wang, Haiyan; Wang, Xiumei; Hao, Qinfang; Yang, Xiaoli; Yang, Xi; Xiao, Xue; Luan, Chunguang; Yang, Yi; Cui, Yujun; Yang, Ruifu; Gao, George F; Song, Yajun; Zhu, Baoli

    2012-04-01

    The spread of the bla(NDM-1) gene is gaining worldwide attentions. This gene is usually carried by large plasmids and has been discovered in diverse bacteria since it was originally found in Klebsiella pneumoniae. Here we report the complete sequences of a bla(NDM-1)-bearing plasmid, pNDM-BJ01, and its variant, pNDM-BJ02, isolated from clinical Acinetobacter lwoffii strains. The plasmid pNDM-BJ01 is 47.3 kb in size and cannot be classified into any known plasmid incompatibility group, thus representing a novel plasmid with an unknown maintenance mechanism. This plasmid contains both a bla(NDM-1) gene and a type IV secretion system (T4SS) gene cluster. The T4SS is assigned to the P-type T4SS group, which usually encode a short, rigid pilus, and the bla(NDM-1) gene is located within a composite transposon flanked by two insertion elements of ISAba125. Plasmid pNDM-BJ02 is nearly identical to pNDM-BJ01 except that one copy of the ISAba125 element is missing, and it is therefore regarded as a variant of pNDM-BJ01. Sequence alignment indicated that this bla(NDM-1)-containing composite transposon, which can also be captured by other mobile elements, was probably a product of multiple recombination events and can move as a whole by transposition.

  10. Crystal Structure of a Type IV Pilus Assembly ATPase: Insights into the Molecular Mechanism of PilB from Thermus thermophilus

    SciTech Connect

    Mancl, Jordan M.; Black, Wesley P.; Robinson, Howard; Yang, Zhaomin; Schubot, Florian D.

    2016-09-22

    Type IV pili (T4P) mediate bacterial motility and virulence. The PilB/GspE family ATPases power the assembly of T4P and type 2 secretion systems. We determined the structure of the ATPase region of PilB (PilBATP) in complex with ATPγS to provide a model of a T4P assembly ATPase and a view of a PilB/GspE family hexamer at better than 3-Å resolution. Spatial positioning and conformations of the protomers suggest a mechanism of force generation. All six PilBATP protomers contain bound ATPγS. Two protomers form a closed conformation poised for ATP hydrolysis. The other four molecules assume an open conformation but separate into two pairs with distinct active-site accessibilities. We propose that one pair represents the post-hydrolysis phase while the other pair appears poised for ADP/ATP exchange. In conclusion, collectively, the data suggest that T4P assembly is powered by coordinating concurrent substrate binding with ATP hydrolysis across the PilB hexamer.

  11. Ehlers-Danlos Syndrome type IV: a multi-exon deletion in one of the two COL3A1 alleles affecting structure, stability, and processing of type III procollagen

    SciTech Connect

    Superti-Furga, A.; Gugler, E.; Gitzelmann, R.; Steinmann, B.

    1988-05-05

    The authors have studied a patient with severe, dominantly inherited Ehlers-Danlos syndrome type IV. The results indicate that this patient carries a deletion of 3.3 kilobase pairs in the triple helical coding domain of one of the two alleles for the pro-..cap alpha..-chains of type III collagen (COL3A1). His cultured skin fibroblasts contain equal amounts of normal length mRNA and of mRNA shortened by approximately 600 bases, and synthesize both normal and shortened pro-..cap alpha..1(III)-chains. In procollagen molecules containing one or more shortened chains, a triple helix is formed with a length of only about 780 amino acids. The mutant procollagen molecules have decreased thermal stability, are less efficiently secreted, and are not processed as their normal counterpart. The deletion in this family is the first mutation to be described in COL3A1.

  12. Chemistry of collagen cross-links: glucose-mediated covalent cross-linking of type-IV collagen in lens capsules.

    PubMed Central

    Bailey, A J; Sims, T J; Avery, N C; Miles, C A

    1993-01-01

    The incubation of lens capsules with glucose in vitro resulted in changes in the mechanical and thermal properties of type-IV collagen consistent with increased cross-linking. Differential scanning calorimetry (d.s.c.) of fresh lens capsules showed two major peaks at melting temperatures Tm 1 and Tm 2 at approx. 54 degrees C and 90 degrees C, which can be attributed to the denaturation of the triple helix and 7S domains respectively. Glycosylation of lens capsules in vitro for 24 weeks caused an increase in Tm 1 from 54 degrees C to 61 degrees C, while non-glycosylated, control incubated capsules increased to a Tm 1 of 57 degrees C. The higher temperature required to denature the type-IV collagen after incubation in vitro suggested increased intermolecular cross-linking. Glycosylated lens capsules were more brittle than fresh samples, breaking at a maximum strain of 36.8 +/- 1.8% compared with 75.6 +/- 6.3% for the fresh samples. The stress at maximum strain (or 'strength') was dramatically reduced from 12.0 to 4.7 N.mm.mg-1 after glycosylation in vitro. The increased constraints within the system leading to loss of strength and increased brittleness suggested not only the presence of more cross-links but a difference in the location of these cross-links compared with the natural lysyl-aldehyde-derived cross-links. The chemical nature of the fluorescent glucose-derived cross-link following glycosylation was determined as pentosidine, at a concentration of 1 pentosidine molecule per 600 collagen molecules after 24 weeks incubation. Pentosidine was also determined in the lens capsules obtained from uncontrolled diabetics at a level of about 1 per 100 collagen molecules. The concentration of these pentosidine cross-links is far too small to account for the observed changes in the thermal and mechanical properties following incubation in vitro, clearly indicating that another as yet undefined, but apparently more important cross-linking mechanism mediated by glucose is

  13. Contribution of alpha3(IV)alpha4(IV)alpha5(IV) Collagen IV to the Mechanical Properties of the Glomerular Basement Membrane

    NASA Astrophysics Data System (ADS)

    Gyoneva, Lazarina

    The glomerular basement membrane (GBM) is a vital part of the blood-urine filtration barrier in the kidneys. In healthy GBMs, the main tension-resisting component is alpha3(IV)alpha4(IV)alpha5(IV) type IV collagen, but in some diseases it is replaced by other collagen IV isoforms. As a result, the GBM becomes leaky and disorganized, ultimately resulting in kidney failure. Our goal is to understanding the biomechanical aspects of the alpha3(IV)alpha4(IV)alpha5(IV) chains and how their absence could be responsible for (1) the initial injury to the GBM and (2) progression to kidney failure. A combination of experiments and computational models were designed for that purpose. A model basement membrane was used to compare experimentally the distensibility of tissues with the alpha3(IV)alpha4(IV)alpha5(IV) chains present and missing. The experiments showed basement membranes containing alpha3(IV)alpha4(IV)alpha5(IV) chains were less distensible. It has been postulated that the higher level of lateral cross-linking (supercoiling) in the alpha3(IV)alpha4(IV)alpha5(IV) networks contributes additional strength/stability to basement membranes. In a computational model of supercoiled networks, we found that supercoiling greatly increased the stiffness of collagen IV networks but only minimally decreased the permeability, which is well suited for the needs of the GBM. It is also known that the alpha3(IV)alpha4(IV)alpha5(IV) networks are more protected from enzymatic degradation, and we explored their significance in GBM remodeling. Our simulations showed that the more protected network was needed to prevent the system from entering a dangerous feedback cycle due to autoregulation mechanisms in the kidneys. Overall, the work adds to the evidence of biomechanical differences between the alpha3(IV)alpha4(IV)alpha5(IV) networks and other collagen IV networks, points to supercoiling as the main source of biomechanical differences, discusses the suitability of alpha3(IV)alpha4(IV

  14. The S(IV)-type Asteroids as Ordinary Chondrite Parent Body Candidates: Implications for the Completeness of the Meteorite Sample of Asteroids

    NASA Astrophysics Data System (ADS)

    Gaffey, M. J.

    1995-09-01

    The discrepancy between the abundance of ordinary chondrites (OCs) among the meteorites and the rarity of unambiguously similar assemblages in the asteroid belt has been a major point of discussion within and between the asteroid and meteorite communities. Various resolutions to this apparent paradox have been proposed [e.g., 1-5], including: 1) interpretations of S-type asteroid spectra are incorrect due to space weathering effects; 2) ordinary chondrites derive from a few rare but favorably situated parent bodies; 3) OCs come from a residual population of small unheated mainbelt asteroids; 4) shock effects darken OC parent body surfaces disguising them as C-type asteroids, and 5) OCs come from inner solar system planetesimals ejected to the Oort cloud which have been recently perturbed into Earth-crossing orbits. Although none of these possibilities has yet been rigorously excluded, recent investigations suggest that the resolution of the apparent paradox lies in some combination of the first three options. For option 3, the discovery of a small mainbelt asteroid with an OC-like spectrum indicates OC-assemblages among the smaller mainbelt asteroids [6], although their abundance is still low in the current sample [7]. For option 2, the mineralogical survey indicated that while most S-asteroids could be rigorously excluded on mineralogical criteria, the S(IV) subtype of this class has silicate compositions within the OC range [8]. The S(IV)-objects are concentrated near the 3:1 secular resonance at 2.5 AU providing an efficient escape into Earth-crossing orbits. Unfortunately for a simple resolution of the OC parent body question, S(IV) spectra still exhibit weaker silicate features and redder spectral slopes than OC assemblages. Although significant uncertainties remain, optical alteration of asteroid surfaces interpreted from the Galileo images of Ida and Gaspra may reconcile the mismatch between OC and S(IV) spectra [option 1]. Although only a subset of the S(IV

  15. Establishment of systemic Brucella melitensis infection through the digestive tract requires urease, the type IV secretion system, and lipopolysaccharide O antigen.

    PubMed

    Paixão, Tatiane A; Roux, Christelle M; den Hartigh, Andreas B; Sankaran-Walters, Sumathi; Dandekar, Satya; Santos, Renato L; Tsolis, Renée M

    2009-10-01

    Human brucellosis is caused mainly by Brucella melitensis, which is often acquired by ingesting contaminated goat or sheep milk and cheese. Bacterial factors required for food-borne infection of humans by B. melitensis are poorly understood. In this study, a mouse model of oral infection was characterized to assess the roles of urease, the VirB type IV secretion system, and lipopolysaccharide for establishing infection through the digestive tract. B. melitensis strain 16M was consistently recovered from the mesenteric lymph node (MLN), spleen, and liver beginning at 3 or 7 day postinfection (dpi). In the gut, persistence of the inoculum was observed up to 21 dpi. No inflammatory lesions were observed in the ileum or colon during infection. Mutant strains lacking the ureABC genes of the ure1 operon, virB2, or pmm encoding phosphomannomutase were constructed and compared to the wild-type strain for infectivity through the digestive tract. Mutants lacking the virB2 and pmm genes were attenuated in the spleen (P < 0.05) and MLN (P < 0.001), respectively. The wild-type and mutant strains had similar levels of resistance to low pH and 5 or 10% bile, suggesting that the reduced colonization of mutants was not the result of reduced resistance to acid pH or bile salts. In an in vitro lymphoepithelial cell (M-cell) model, B. melitensis transited rapidly through polarized enterocyte monolayers containing M-like cells; however, transit through monolayers containing only enterocytes was reduced or absent. These results indicate that B. melitensis is able to spread systemically from the digestive tract after infection, most likely through M cells of the mucosa-associated lymphoid tissue.

  16. The association of the IVS1-397T>C estrogen receptor α polymorphism with the regulatory conditions in longstanding type 1 diabetic girls.

    PubMed

    Ryba, Monika; Malinowska, Ewa; Rybarczyk-Kapturska, Karolina; Brandt, Agnieszka; Myśliwiec, Małgorzata; Myśliwska, Jolanta

    2011-10-01

    Type 1 diabetes is considered as pluricausal disease, whose etiology involves genetic predisposition as well as environmental factors that contribute to disease progression and pathogenesis. Women are believed to be more susceptible to develop autoimmune diseases, which may depend in part on the influence of sex hormones on the immune system. It was shown that estrogens may protect against the development of autoimmune disease by inducing the expansion of regulatory T cell pool and upregulating Foxp3 expression. Foxp3 is a transcription factor that controls the development and suppressive function of naturally occurring regulatory T cells CD4(+)Foxp3(+). Longstanding diabetes type 1 has features of low-grade chronic inflammation which may influence regulatory T cell subset by reducing their numbers or/and inhibiting their suppressive potential. As diabetic type 1 patients are differentiated with regard to metabolic factors, level of glycemic control and systemic inflammatory state, we aimed to examine if this can be associated with IVSI-397T>C estrogen receptor α polymorphism. We examined 93 young regularly menstruating girls with diagnosed type 1 diabetes and 49 healthy age-matched control individuals. The PvuII polymorphism of the ER-α gene was analyzed as well as the serum TNF level and the level of CD4(+)Foxp3(+) regulatory T cells in these individuals. Girls with type 1 diabetes had lower level of CD4(+)Foxp3(+) Tregs than their healthy counterparts. Regulatory T cells from these patients showed also lower expression of Foxp3 than Tregs in healthy, control group. In addition, DM1 girls bearing the CC genotypes showed the highest level of CD4(+)Foxp3(+) Tregs and the lowest TNF serum level in comparison to girls carrying CT or TT genotype. The CC DM1 carriers had also higher serum level of estrogens than girls bearing CT or TT genotype. We propose that different variants of IVS1-397 estrogen receptor α polymorphism may become additional genetic factor that

  17. Asteroids IV

    NASA Astrophysics Data System (ADS)

    Michel, Patrick; DeMeo, Francesca E.; Bottke, William F.

    . Asteroids, like planets, are driven by a great variety of both dynamical and physical mechanisms. In fact, images sent back by space missions show a collection of small worlds whose characteristics seem designed to overthrow our preconceived notions. Given their wide range of sizes and surface compositions, it is clear that many formed in very different places and at different times within the solar nebula. These characteristics make them an exciting challenge for researchers who crave complex problems. The return of samples from these bodies may ultimately be needed to provide us with solutions. In the book Asteroids IV, the editors and authors have taken major strides in the long journey toward a much deeper understanding of our fascinating planetary ancestors. This book reviews major advances in 43 chapters that have been written and reviewed by a team of more than 200 international authorities in asteroids. It is aimed to be as comprehensive as possible while also remaining accessible to students and researchers who are interested in learning about these small but nonetheless important worlds. We hope this volume will serve as a leading reference on the topic of asteroids for the decade to come. We are deeply indebted to the many authors and referees for their tremendous efforts in helping us create Asteroids IV. We also thank the members of the Asteroids IV scientific organizing committee for helping us shape the structure and content of the book. The conference associated with the book, "Asteroids Comets Meteors 2014" held June 30-July 4, 2014, in Helsinki, Finland, did an outstanding job of demonstrating how much progress we have made in the field over the last decade. We are extremely grateful to our host Karri Muinonnen and his team. The editors are also grateful to the Asteroids IV production staff, namely Renée Dotson and her colleagues at the Lunar and Planetary Institute, for their efforts, their invaluable assistance, and their enthusiasm; they made life as

  18. 3D structure/function analysis of PilX reveals how minor pilins can modulate the virulence properties of type IV pili

    PubMed Central

    Helaine, Sophie; Dyer, David H.; Nassif, Xavier; Pelicic, Vladimir; Forest, Katrina T.

    2007-01-01

    Type IV pili (Tfp) are widespread filamentous bacterial organelles that mediate multiple virulence-related phenotypes. They are composed mainly of pilin subunits, which are processed before filament assembly by dedicated prepilin peptidases. Other proteins processed by these peptidases, whose molecular nature and mode of action remain enigmatic, play critical roles in Tfp biology. We have performed a detailed structure/function analysis of one such protein, PilX from Neisseria meningitidis, which is crucial for formation of bacterial aggregates and adhesion to human cells. The x-ray crystal structure of PilX reveals the α/β roll fold shared by all pilins, and we show that this protein colocalizes with Tfp. These observations suggest that PilX is a minor, or low abundance, pilin that assembles within the filaments in a similar way to pilin. Deletion of a PilX distinctive structural element, which is predicted to be exposed on the filament surface, abolishes aggregation and adhesion. Our results support a model in which surface-exposed motifs in PilX subunits stabilize bacterial aggregates against the disruptive force of pilus retraction and illustrate how a minor pilus component can enhance the functional properties of pili of rather simple composition and structure. PMID:17893339

  19. CryoEM structure of the Methanospirillum hungatei archaellum reveals structural features distinct from the bacterial flagellum and type IV pili.

    PubMed

    Poweleit, Nicole; Ge, Peng; Nguyen, Hong H; Loo, Rachel R Ogorzalek; Gunsalus, Robert P; Zhou, Z Hong

    2016-12-05

    Archaea use flagella known as archaella-distinct both in protein composition and structure from bacterial flagella-to drive cell motility, but the structural basis of this function is unknown. Here, we report an atomic model of the archaella, based on the cryo electron microscopy (cryoEM) structure of the Methanospirillum hungatei archaellum at 3.4 Å resolution. Each archaellum contains ∼61,500 archaellin subunits organized into a curved helix with a diameter of 10 nm and average length of 10,000 nm. The tadpole-shaped archaellin monomer has two domains, a β-barrel domain and a long, mildly kinked α-helix tail. Our structure reveals multiple post-translational modifications to the archaella, including six O-linked glycans and an unusual N-linked modification. The extensive interactions among neighbouring archaellins explain how the long but thin archaellum maintains the structural integrity required for motility-driving rotation. These extensive inter-subunit interactions and the absence of a central pore in the archaellum distinguish it from both the bacterial flagellum and type IV pili.

  20. Systematic site-directed mutagenesis of the Helicobacter pylori CagL protein of the Cag type IV secretion system identifies novel functional domains

    PubMed Central

    Bönig, Tobias; Olbermann, Patrick; Bats, Simon H.; Fischer, Wolfgang; Josenhans, Christine

    2016-01-01

    The Cag Type IV secretion system, which contributes to inflammation and cancerogenesis during chronic infection, is one of the major virulence factors of the bacterial gastric pathogen Helicobacter pylori. We have generated and characterized a series of non-marked site-directed chromosomal mutants in H. pylori to define domains of unknown function of the essential tip protein CagL of the Cag secretion system. Characterizing the CagL mutants, we determined that their function to activate cells and transport the effector CagA was reduced to different extents. We identified three novel regions of the CagL protein, involved in its structural integrity, its possible interaction with the CagPAI T4SS pilus protein CagI, and in its binding to integrins and other host cell ligands. In particular two novel variable CagL motifs were involved in integrin binding, TSPSA, and TASLI, which is located opposite of its integrin binding motif RGD. We thereby defined functionally important subdomains within the CagL structure, which can be used to clarify CagL contributions in the context of other CagPAI proteins or for inhibition of the CagT4SS. This structure-function correlation of CagL domains can also be instructive for the functional characterization of other potential VirB5 orthologs whose structure is not yet known. PMID:27922023

  1. TgaA, a VirB1-Like Component Belonging to a Putative Type IV Secretion System of Bifidobacterium bifidum MIMBb75

    PubMed Central

    Balzaretti, Silvia; Taverniti, Valentina; Miriani, Matteo; Milani, Christian; Scarafoni, Alessio; Corona, Silvia; Ciranna, Alessandro; Arioli, Stefania; Santala, Ville; Iametti, Stefania; Bonomi, Francesco; Ventura, Marco; Mora, Diego; Karp, Matti

    2014-01-01

    Bifidobacterium bifidum MIMBb75 is a human intestinal isolate demonstrated to be interactive with the host and efficacious as a probiotic. However, the molecular biology of this microorganism is yet largely unknown. For this reason, we undertook whole-genome sequencing of B. bifidum MIMBb75 to identify potential genetic factors that would explain the metabolic and probiotic attributes of this bacterium. Comparative genomic analysis revealed a 45-kb chromosomal region that comprises 19 putative genes coding for a potential type IV secretion system (T4SS). Thus, we undertook the initial characterization of this genetic region by studying the putative virB1-like gene, named tgaA. Gene tgaA encodes a peptidoglycan lytic enzyme containing two active domains: lytic murein transglycosylase (LT, cd00254.3) and cysteine- and histidine-dependent amidohydrolase/peptidase (CHAP, pfam05257.4). By means of several in vitro assays, we experimentally confirmed that protein TgaA, consistent with its computationally assigned role, has peptidoglycan lytic activity, which is principally associated to the LT domain. Furthermore, immunofluorescence and immunogold labeling showed that the protein TgaA is abundantly expressed on the cell surface of B. bifidum MIMBb75. According to the literature, the T4SSs, which have not been characterized before in bifidobacteria, can have important implications for bacterial cell-to-cell communication as well as cross talk with host cells, justifying the interest for further studies aimed at the investigation of this genetic region. PMID:24951779

  2. TgaA, a VirB1-like component belonging to a putative type IV secretion system of Bifidobacterium bifidum MIMBb75.

    PubMed

    Guglielmetti, Simone; Balzaretti, Silvia; Taverniti, Valentina; Miriani, Matteo; Milani, Christian; Scarafoni, Alessio; Corona, Silvia; Ciranna, Alessandro; Arioli, Stefania; Santala, Ville; Iametti, Stefania; Bonomi, Francesco; Ventura, Marco; Mora, Diego; Karp, Matti

    2014-09-01

    Bifidobacterium bifidum MIMBb75 is a human intestinal isolate demonstrated to be interactive with the host and efficacious as a probiotic. However, the molecular biology of this microorganism is yet largely unknown. For this reason, we undertook whole-genome sequencing of B. bifidum MIMBb75 to identify potential genetic factors that would explain the metabolic and probiotic attributes of this bacterium. Comparative genomic analysis revealed a 45-kb chromosomal region that comprises 19 putative genes coding for a potential type IV secretion system (T4SS). Thus, we undertook the initial characterization of this genetic region by studying the putative virB1-like gene, named tgaA. Gene tgaA encodes a peptidoglycan lytic enzyme containing two active domains: lytic murein transglycosylase (LT, cd00254.3) and cysteine- and histidine-dependent amidohydrolase/peptidase (CHAP, pfam05257.4). By means of several in vitro assays, we experimentally confirmed that protein TgaA, consistent with its computationally assigned role, has peptidoglycan lytic activity, which is principally associated to the LT domain. Furthermore, immunofluorescence and immunogold labeling showed that the protein TgaA is abundantly expressed on the cell surface of B. bifidum MIMBb75. According to the literature, the T4SSs, which have not been characterized before in bifidobacteria, can have important implications for bacterial cell-to-cell communication as well as cross talk with host cells, justifying the interest for further studies aimed at the investigation of this genetic region.

  3. Identification of new protein-protein interactions involving the products of the chromosome- and plasmid-encoded type IV secretion loci of the phytopathogen Xanthomonas axonopodis pv. citri.

    PubMed

    Alegria, Marcos C; Souza, Diorge P; Andrade, Maxuel O; Docena, Cassia; Khater, Leticia; Ramos, Carlos H I; da Silva, Ana C R; Farah, Chuck S

    2005-04-01

    The recently sequenced genome of the bacterial plant pathogen Xanthomonas axonopodis pv. citri contains two virB gene clusters, one on the chromosome and one on a 64-kb plasmid, each of which codes for a previously uncharacterized type IV secretion system (T4SS). Here we used a yeast two-hybrid assay to identify protein-protein interactions in these two systems. Our results revealed interactions between known T4SS components as well as previously uncharacterized interactions involving hypothetical proteins coded by open reading frames in the two X. axonopodis pv. citri virB loci. Our results indicate that both loci may code for previously unidentified VirB7 proteins, which we show interact with either VirB6 or VirB9 or with a hypothetical protein coded by the same locus. Furthermore, a set of previously uncharacterized Xanthomonas proteins have been found to interact with VirD4, whose gene is adjacent to the chromosomal virB locus. The gene for one member of this family is found within the chromosomal virB locus. All these uncharacterized proteins possess a conserved 120-amino-acid domain in their C termini and may represent a family of cofactors or substrates of the Xanthomonas T4SS.

  4. A conserved type IV pilin signal peptide H-domain is critical for the post-translational regulation of flagella-dependent motility.

    PubMed

    Esquivel, Rianne N; Pohlschroder, Mechthild

    2014-08-01

    In many bacteria and archaea, type IV pili facilitate surface adhesion, the initial step in biofilm formation. Haloferax volcanii has a specific set of adhesion pilins (PilA1-A6) that, although diverse, contain an absolutely conserved signal peptide hydrophobic (H) domain. Data presented here demonstrate that these pilins (PilA1-A6) also play an important role in regulating flagella-dependent motility, which allows cells to rapidly transition between planktonic and sessile states. Cells lacking adhesion pilins exhibit a severe motility defect, however, expression of any one of the adhesion pilins in trans can rescue the motility and adhesion. Conversely, while deleting pilB3-C3, genes required for PilA pilus biosynthesis, results in cells lacking pili and having an adhesion defect, it does not affect motility, indicating that motility regulation requires the presence of pilins, but not assembled pili. Mutagenesis studies revealed that the pilin-dependent motility regulatory mechanism does not require the diverse C-terminal region of the PilA pilins but specifically involves the conserved H-domain. This novel post-translational regulatory mechanism, which employs components that promote biofilm formation to inhibit motility, can provide a rapid response to changing environmental conditions. A model for this regulatory mechanism, which may also be present in other prokaryotes, is discussed.

  5. [Evaluation of chemotherapy for stage IV non-small cell lung cancer employing a regression tree type method for quality-adjusted survival analysis to determine prognostic factors].

    PubMed

    Fujita, A; Takabatake, H; Tagaki, S; Sohda, T; Sekine, K

    1996-03-01

    To evaluate the effect of chemotherapy on QOL, the survival period was categorized by 3 intervals: one in the hospital for chemotherapy (TOX), on an outpatient basis (TWiST Time without Symptom and Toxicity), and in the hospital for conservative therapy (REL). Coefficients showing the QOL level were expressed as ut, uw and ur. If uw was 1 and ut and ur were plotted at less than 1, ut TOX+uwTWiST+urREL could be a quality-adjusted value relative to TWiST (Q-TWiST). One hundred five patients with stage IV non-small cell lung cancer were included. Sixty-five were given chemotherapy, and the other 40 were not. The observation period was 2 years. Q-TWiST values for age, sex, PS, histology and chemotherapy were calculated. Their quantification was performed employing a regression tree type method. Chemotherapy contributed to Q-TWiST when ut approached 1 i.e., no side effect was supposed). When ut was less than 0.5, PS and sex had an appreciable role.

  6. PilF Is an Outer Membrane Lipoprotein Required for Multimerization and Localization of the Pseudomonas aeruginosa Type IV Pilus Secretin

    SciTech Connect

    Koo, J.; Tammam, S; Ku, S; Samplaeanu, L; Burrows, L; Howell, P

    2008-01-01

    Type IV pili (T4P) are retractile appendages that contribute to the virulence of bacterial pathogens. PilF is a Pseudomonas aeruginosa lipoprotein that is essential for T4P biogenesis. Phenotypic characterization of a pilF mutant confirmed that T4P-mediated functions are abrogated: T4P were no longer present on the cell surface, twitching motility was abolished, and the mutant was resistant to infection by T4P retraction-dependent bacteriophage. The results of cellular fractionation studies indicated that PilF is the outer membrane pilotin required for the localization and multimerization of the secretin, PilQ. Mutation of the putative PilF lipidation site untethered the protein from the outer membrane, causing secretin assembly in both inner and outer membranes. T4P-mediated twitching motility and bacteriophage susceptibility were moderately decreased in the lipidation site mutant, while cell surface piliation was substantially reduced. The tethering of PilF to the outer membrane promotes the correct localization of PilQ and appears to be required for the formation of stable T4P. Our 2.0-A structure of PilF revealed a superhelical arrangement of six tetratricopeptide protein-protein interaction motifs that may mediate the contacts with PilQ during secretin assembly. An alignment of pseudomonad PilF sequences revealed three highly conserved surfaces that may be involved in PilF function.

  7. Congenital Insensitivity to Pain with Anhidrosis (HSAN Type IV), Extremely Rare Syndrome that Can Be Easily Missed by Bone and Joint Surgeons: A Case Report

    PubMed Central

    Ali, Nadeem; Sharma, Sudesh; Sharma, Sonali; Kamal, Younis; Sharma, Sushil

    2012-01-01

    Background Congenital insensitivity to pain with anhidrosis is an extremely rare disorder in which injuries can often be missed by patient, parents and even by orthopedic surgeon. Pain and tenderness, on which a trauma team so much depends to make a clinical diagnosis and to decide whether to go for radiological evaluation can be misleading in this rare syndrome. So complete clinical examination still forms the corner stone to avoid misdiagnosis and pick up the rare disorders. Case Presentation We present a 5 year old girl child, who was brought to us as a case of one and a half month old neglected trauma left leg and was diagnosed to be suffering from congenital insensitivity to pain with anhidrosis (HSAN Type IV). Conclusion Congenital insensitivity to pain with anhidrosis is extremely rare entity, in which patients are subjected to repeated injuries which are often neglected. There is no specific treatment but patient training and parent education are key to avoid further neglect and damage. PMID:23429452

  8. Tumstatin, the NC1 domain of {alpha}3 chain of type IV collagen, is an endogenous inhibitor of pathological angiogenesis and suppresses tumor growth

    SciTech Connect

    Hamano, Yuki; Kalluri, Raghu . E-mail: rkalluri@bidmc.harvard.edu

    2005-07-29

    Angiogenesis, the formation of new blood vessels, is required for physiological development of vertebrates and repair of damaged tissue, but in the pathological setting contributes to progression of cancer. During tumor growth, angiogenesis is supported by up-regulation of angiogenic stimulators (pro-angiogenic) and down-regulation of angiogenic inhibitors (anti-angiogenic). The switch to the angiogenic phenotype (angiogenic switch) allows the tumors to grow and facilitate metastasis. The bioactive NC1 domain of type IV collagen {alpha}3 chain, called tumstatin, imparts anti-tumor activity by inducing apoptosis of proliferating endothelial cells. Tumstatin binds to {alpha}V{beta}3 integrin via a mechanism independent of the RGD-sequence recognition and inhibits cap-dependent protein synthesis in the proliferating endothelial cells. The physiological level of tumstatin is controlled by matrix metalloproteinase-9, which most effectively cleaves it from the basement membrane and its physiological concentration in the circulation keeps pathological angiogenesis and tumor growth in check. These findings suggest that tumstatin functions as an endogenous inhibitor of pathological angiogenesis and functions as a novel suppressor of proliferating endothelial cells and growth of tumors.

  9. The Predicted ABC Transporter AbcEDCBA Is Required for Type IV Secretion System Expression and Lysosomal Evasion by Brucella ovis

    PubMed Central

    Silva, Teane M. A.; Mol, Juliana P. S.; Winter, Maria G.; Atluri, Vidya; Xavier, Mariana N.; Pires, Simone F.; Paixão, Tatiane A.; Andrade, Hélida M.; Santos, Renato L.; Tsolis, Renee M.

    2014-01-01

    Brucella ovis is a major cause of reproductive failure in rams and it is one of the few well-described Brucella species that is not zoonotic. Previous work showed that a B. ovis mutant lacking a species-specific ABC transporter (ΔabcBA) was attenuated in mice and was unable to survive in macrophages. The aim of this study was to evaluate the role of this ABC transporter during intracellular survival of B. ovis. In HeLa cells, B. ovis WT was able to survive and replicate at later time point (48 hpi), whereas an ΔabcBA mutant was attenuated at 24 hpi. The reduced survival of the ΔabcBA mutant was associated with a decreased ability to exclude the lysosomal marker LAMP1 from its vacuolar membrane, suggesting a failure to establish a replicative niche. The ΔabcBA mutant showed a reduced abundance of the Type IV secretion system (T4SS) proteins VirB8 and VirB11 in both rich and acid media, when compared to WT B. ovis. However, mRNA levels of virB1, virB8, hutC, and vjbR were similar in both strains. These results support the notion that the ABC transporter encoded by abcEDCBA or its transported substrate acts at a post-transcriptional level to promote the optimal expression of the B. ovis T4SS within infected host cells. PMID:25474545

  10. Two novel splicing mutations in the SLC45A2 gene cause Oculocutaneous Albinism Type IV by unmasking cryptic splice sites.

    PubMed

    Straniero, Letizia; Rimoldi, Valeria; Soldà, Giulia; Mauri, Lucia; Manfredini, Emanuela; Andreucci, Elena; Bargiacchi, Sara; Penco, Silvana; Gesu, Giovanni P; Del Longo, Alessandra; Piozzi, Elena; Asselta, Rosanna; Primignani, Paola

    2015-09-01

    Oculocutaneous albinism (OCA) is characterized by hypopigmentation of the skin, hair and eye, and by ophthalmologic abnormalities caused by a deficiency in melanin biosynthesis. OCA type IV (OCA4) is one of the four commonly recognized forms of albinism, and is determined by mutation in the SLC45A2 gene. Here, we investigated the genetic basis of OCA4 in an Italian child. The mutational screening of the SLC45A2 gene identified two novel potentially pathogenic splicing mutations: a synonymous transition (c.888G>A) involving the last nucleotide of exon 3 and a single-nucleotide insertion (c.1156+2dupT) within the consensus sequence of the donor splice site of intron 5. As computer-assisted analysis for mutant splice-site prediction was not conclusive, we investigated the effects on pre-mRNA splicing of these two variants by using an in vitro minigene approach. Production of mutant transcripts in HeLa cells demonstrated that both mutations cause the almost complete abolishment of the physiologic donor splice site, with the concomitant unmasking of cryptic donor splice sites. To our knowledge, this work represents the first in-depth molecular characterization of splicing defects in a OCA4 patient.

  11. Disease-Associated Neisseria meningitidis Isolates Inhibit Wound Repair in Respiratory Epithelial Cells in a Type IV Pilus-Independent Manner

    PubMed Central

    Ren, Xiaoyun

    2014-01-01

    Neisseria meningitidis is the causative agent of meningococcal disease. Onset of meningococcal disease can be extremely rapid and can kill within a matter of hours. However, although a much-feared pathogen, Neisseria meningitidis is frequently found in the nasopharyngeal mucosae of healthy carriers. The bacterial factors that distinguish disease- from carriage-associated meningococci are incompletely understood. Evidence suggesting that disruptions to the nasopharynx may increase the risk of acquiring meningococcal disease led us to evaluate the ability of disease- and carriage-associated meningococcal isolates to inhibit cell migration, using an in vitro assay for wound repair. We found that disease-associated isolates in our collection inhibited wound closure, while carriage-associated isolates were more variable, with many isolates not inhibiting wound repair at all. For isolates selected for further study, we found that actin morphology, such as presence of lamellipodia, correlated with cell migration. We demonstrated that multiple meningococcal virulence factors, including the type IV pili, are dispensable for inhibition of wound repair. Inhibition of wound repair was also shown to be an active process, i.e., requiring live bacteria undergoing active protein synthesis. PMID:25225250

  12. Identification of a novel collagen type IV alpha-4 (COL4A4) mutation in a Chinese family with autosomal dominant Alport syndrome using exome sequencing

    PubMed Central

    Deng, Sheng; Xu, Hongbo; Yuan, Jinzhong; Xiao, Jingjing; Yuan, Lamei; Deng, Xiong; Guan, Liping; Zhu, Anding; Rong, Pengfei; Zhang, Jianguo; Deng, Hao

    2016-01-01

    Background & objectives: Alport syndrome (AS) is an inherited disorder characterized by glomerulonephritis and end-stage renal disease (ESRD). The aim of this study was to identify the gene responsible for the glomerulopathy in a Chinese family with autosomal dominant AS using exome sequencing. Methods: A 4-generation, 30-member Chinese Han family was enrolled in this study. Exome sequencing was conducted in the proband of the family, and then direct sequencing was performed in family members of the pedigree and 100 normal controls. Results: A novel frameshift mutation, c.3213delA (p.Gly1072Glufs*69), in the collagen type IV alpha-4 gene (COL4A4) was found to be the genetic cause. Neither sensorineural hearing loss nor ocular abnormalities were present in the patients of this family. Other clinical features, such as age of onset, age of ESRD occurring and disease severity, varied among the patients of this family. Interpretation & conclusions: A novel frameshift mutation, c.3213delA (p.Gly1072Glufs*69) in the COL4A4 gene, was identified in the Chinese pedigree with autosomal dominant AS. Our findings may provide new insights into the cause and diagnosis of AS and also have implications for genetic counselling. PMID:27934798

  13. Fabrication of a Core-Shell-Type Photocatalyst via Photodeposition of Group IV and V Transition Metal Oxyhydroxides: An Effective Surface Modification Method for Overall Water Splitting.

    PubMed

    Takata, Tsuyoshi; Pan, Chengsi; Nakabayashi, Mamiko; Shibata, Naoya; Domen, Kazunari

    2015-08-05

    The design of optimal surface structures for photocatalysts is a key to efficient overall water splitting into H2 and O2. A unique surface modification method was devised for a photocatalyst to effectively promote overall water splitting. Photodeposition of amorphous oxyhydroxides of group IV and V transition metals (Ti, Nb, Ta) over a semiconductor photocatalyst from corresponding water-soluble metal peroxide complexes was examined. In this method, amorphous oxyhydroxide covered the whole surface of the photocatalyst particles, creating a core-shell structure. The water splitting behavior of the novel core-shell-type photocatalyst in relation to the permeation behavior of the coating layer was investigated in detail. Overall water splitting proceeded successfully after the photodeposition, owing to the prevention of the reverse reaction. The photodeposited oxyhydroxide layers were found to function as molecular sieves, selectively filtering reactant and product molecules. By exploiting the selective permeability of the coating layer, redox reactions on the photocatalyst surface could be suitably controlled, which resulted in successful overall water splitting.

  14. Membrane traffic and turnover in TRP-ML1–deficient cells: a revised model for mucolipidosis type IV pathogenesis

    PubMed Central

    Miedel, Mark T.; Rbaibi, Youssef; Guerriero, Christopher J.; Colletti, Grace; Weixel, Kelly M.; Weisz, Ora A.; Kiselyov, Kirill

    2008-01-01

    The lysosomal storage disorder mucolipidosis type IV (MLIV) is caused by mutations in the transient receptor potential–mucolipin-1 (TRP-ML1) ion channel. The “biogenesis” model for MLIV pathogenesis suggests that TRP-ML1 modulates postendocytic delivery to lysosomes by regulating interactions between late endosomes and lysosomes. This model is based on observed lipid trafficking delays in MLIV patient fibroblasts. Because membrane traffic aberrations may be secondary to lipid buildup in chronically TRP-ML1–deficient cells, we depleted TRP-ML1 in HeLa cells using small interfering RNA and examined the effects on cell morphology and postendocytic traffic. TRP-ML1 knockdown induced gradual accumulation of membranous inclusions and, thus, represents a good model in which to examine the direct effects of acute TRP-ML1 deficiency on membrane traffic. Ratiometric imaging revealed decreased lysosomal pH in TRP-ML1–deficient cells, suggesting a disruption in lysosomal function. Nevertheless, we found no effect of TRP-ML1 knockdown on the kinetics of protein or lipid delivery to lysosomes. In contrast, by comparing degradation kinetics of low density lipoprotein constituents, we confirmed a selective defect in cholesterol but not apolipoprotein B hydrolysis in MLIV fibroblasts. We hypothesize that the effects of TRP-ML1 loss on hydrolytic activity have a cumulative effect on lysosome function, resulting in a lag between TRP-ML1 loss and full manifestation of MLIV. PMID:18504305

  15. Helicobacter pylori CagL Y58/E59 Mutation Turns-Off Type IV Secretion-Dependent Delivery of CagA into Host Cells

    PubMed Central

    Tegtmeyer, Nicole; Lind, Judith; Schmid, Benedikt; Backert, Steffen

    2014-01-01

    The type IV secretion system (T4SS) is a major virulence determinant of the gastric pathogen Helicobacter pylori. The CagL protein is a specialized adhesin of the corresponding T4SS pilus, which establishes initial contact with the integrin β1 receptor on host target cells. Recent studies proposed that Y58 and E59 amino acid polymorphisms in CagL increase the virulence of H. pylori strains by enhanced translocation and phosphorylation of the CagA effector protein. These polymorphisms were therefore correlated with an increased risk of gastric cancer development. Here we show that the Y58/E59 motif, which is located in a loop connecting two α-helices, and corresponding polymorphisms could influence the function of CagL. However, expression of isogenic CagL Y58/E59 variants in H. pylori strain 26695 significantly blocked the translocation and phosphorylation of CagA as compared to complemented wild-type CagL. These results suggest that the function of the T4SS for delivery of CagA is turned-off by the Y58/E59 mutation in CagL. This activity appears to be similar to the one recently described for another T4SS pilus protein, CagY, which is also sufficient to cause gain or loss of T4SS function. These data support the hypothesis that certain mutations in CagL or recombination events in CagY may serve as a sort of molecular switch or perhaps rheostat in the T4SS, which could alter the function of the pilus and "tunes" injection of CagA and host pro-inflammatory responses, respectively. PMID:24893039

  16. Critical role of ASC inflammasomes and bacterial type IV secretion system in caspase-1 activation and host innate resistance to Brucella abortus infection.

    PubMed

    Gomes, Marco Tulio R; Campos, Priscila C; Oliveira, Fernanda S; Corsetti, Patricia P; Bortoluci, Karina R; Cunha, Larissa D; Zamboni, Dario S; Oliveira, Sergio C

    2013-04-01

    Pathogens are detected by innate immune receptors that, upon activation, orchestrate an appropriate immune response. Recent studies revealed the intracellular signaling cascades involved in the TLR-initiated immune response to Brucella abortus infection. However, no report has elucidated the role of inflammasome receptors in Brucella recognition. Therefore, we decided to investigate the function of NLRC4, NLRP3, and AIM2 in sensing Brucella. In this study, we showed that NLRC4 is not required to induce caspase-1 activation and further secretion of IL-1β by B. abortus in macrophages. In contrast, we determined that AIM2, which senses Brucella DNA, and NLRP3 are partially required for caspase-1 activation and IL-1β secretion. Additionally, mitochondrial reactive oxygen species induced by Brucella were implicated in IL-1β production. Furthermore, AIM2, NLRP3, ASC, and caspase-1 knockout mice were more susceptible to B. abortus infection than were wild-type animals, suggesting that multiple ASC-dependent inflammasomes contribute to host protection against infection. This protective effect is due to the inflammatory response caused by IL-1β and IL-18 rather than pyroptosis, because we observed augmented bacterial burden in IL-1R and IL-18 knockout mice. Finally, we determined that bacterial type IV secretion system VirB and live, but not heat-killed, Brucella are required for full inflammasome activation in macrophages during infection. Taken together, our results indicate that Brucella is sensed by ASC inflammasomes that collectively orchestrate a robust caspase-1 activation and proinflammatory response.

  17. Animal Protection and Structural Studies of a Consensus Sequence Vaccine Targeting the Receptor Binding Domain of the Type IV Pilus of Pseudomonas aeruginosa

    SciTech Connect

    Kao, Daniel J.; Churchill, Mair E.A.; Irvin, Randall T.; Hodges, Robert S.

    2008-09-23

    One of the main obstacles in the development of a vaccine against Pseudomonas aeruginosa is the requirement that it is protective against a wide range of virulent strains. We have developed a synthetic-peptide consensus-sequence vaccine (Cs1) that targets the host receptor-binding domain (RBD) of the type IV pilus of P. aeruginosa. Here, we show that this vaccine provides increased protection against challenge by the four piliated strains that we have examined (PAK, PAO, KB7 and P1) in the A.BY/SnJ mouse model of acute P. aeruginosa infection. To further characterize the consensus sequence, we engineered Cs1 into the PAK monomeric pilin protein and determined the crystal structure of the chimeric Cs1 pilin to 1.35 {angstrom} resolution. The substitutions (T130K and E135P) used to create Cs1 do not disrupt the conserved backbone conformation of the pilin RBD. In fact, based on the Cs1 pilin structure, we hypothesize that the E135P substitution bolsters the conserved backbone conformation and may partially explain the immunological activity of Cs1. Structural analysis of Cs1, PAK and K122-4 pilins reveal substitutions of non-conserved residues in the RBD are compensated for by complementary changes in the rest of the pilin monomer. Thus, the interactions between the RBD and the rest of the pilin can either be mediated by polar interactions of a hydrogen bond network in some strains or by hydrophobic interactions in others. Both configurations maintain a conserved backbone conformation of the RBD. Thus, the backbone conformation is critical in our consensus-sequence vaccine design and that cross-reactivity of the antibody response may be modulated by the composition of exposed side-chains on the surface of the RBD. This structure will guide our future vaccine design by focusing our investigation on the four variable residue positions that are exposed on the RBD surface.

  18. Large-scale study of the interactions between proteins involved in type IV pilus biology in Neisseria meningitidis: characterization of a subcomplex involved in pilus assembly.

    PubMed

    Georgiadou, Michaella; Castagnini, Marta; Karimova, Gouzel; Ladant, Daniel; Pelicic, Vladimir

    2012-06-01

    The functionally versatile type IV pili (Tfp) are one of the most widespread virulence factors in bacteria. However, despite generating much research interest for decades, the molecular mechanisms underpinning the various aspects of Tfp biology remain poorly understood, mainly because of the complexity of the system. In the human pathogen Neisseria meningitidis for example, 23 proteins are dedicated to Tfp biology, 15 of which are essential for pilus biogenesis. One of the important gaps in our knowledge concerns the topology of this multiprotein machinery. Here we have used a bacterial two-hybrid system to identify and quantify the interactions between 11 Pil proteins from N. meningitidis. We identified 20 different binary interactions, many of which are novel. This represents the most complex interaction network between Pil proteins reported to date and indicates, among other things, that PilE, PilM, PilN and PilO, which are involved in pilus assembly, indeed interact. We focused our efforts on this subset of proteins and used a battery of assays to determine the membrane topology of PilN and PilO, map the interaction domains between PilE, PilM, PilN and PilO, and show that a widely conserved N-terminal motif in PilN is essential for both PilM-PilN interactions and pilus assembly. Finally, we show that PilP (another protein involved in pilus assembly) forms a complex with PilM, PilN and PilO. Taken together, these findings have numerous implications for understanding Tfp biology and provide a useful blueprint for future studies.

  19. Evolutionary dynamics of pathoadaptation revealed by three independent acquisitions of the VirB/D4 type IV secretion system in Bartonella.

    PubMed

    Harms, Alexander; Segers, Francisca H I D; Quebatte, Maxime; Mistl, Claudia; Manfredi, Pablo; Körner, Jonas; Chomel, Bruno B; Kosoy, Michael; Maruyama, Soichi; Engel, Philipp; Dehio, Christoph

    2017-03-07

    The α-proteobacterial genus Bartonella comprises a group of ubiquitous mammalian pathogens that are studied as a model for the evolution of bacterial pathogenesis. Vast abundance of two particular phylogenetic lineages of Bartonella had been linked to enhanced host adaptability enabled by lineage-specific acquisition of a VirB/D4 type IV secretion system (T4SS) and parallel evolution of complex effector repertoires. However, the limited availability of genome sequences from one of those lineages as well as other, remote branches of Bartonella has so far hampered comprehensive understanding of how the VirB/D4 T4SS and its effectors called Beps have shaped Bartonella evolution. Here, we report the discovery of a third repertoire of Beps associated with the VirB/D4 T4SS of B. ancashensis, a novel human pathogen that lacks any signs of host adaptability and is only distantly related to the two species-rich lineages encoding a VirB/D4 T4SS. Furthermore, sequencing of ten new Bartonella isolates from under-sampled lineages enabled combined in silico analyses and wet lab experiments that suggest several parallel layers of functional diversification during evolution of the three Bep repertoires from a single ancestral effector. Our analyses show that the Beps of B. ancashensis share many features with the two other repertoires, but may represent a more ancestral state that has not yet unleashed the adaptive potential of such an effector set. We anticipate that the effectors of B. ancashensis will enable future studies to dissect the evolutionary history of Bartonella effectors and help unraveling the evolutionary forces underlying bacterial host adaptation.

  20. Fic domain-catalyzed adenylylation: Insight provided by the structural analysis of the type IV secretion system effector BepA

    PubMed Central

    Palanivelu, Dinesh V; Goepfert, Arnaud; Meury, Marcel; Guye, Patrick; Dehio, Christoph; Schirmer, Tilman

    2011-01-01

    Numerous bacterial pathogens subvert cellular functions of eukaryotic host cells by the injection of effector proteins via dedicated secretion systems. The type IV secretion system (T4SS) effector protein BepA from Bartonella henselae is composed of an N-terminal Fic domain and a C-terminal Bartonella intracellular delivery domain, the latter being responsible for T4SS-mediated translocation into host cells. A proteolysis resistant fragment (residues 10–302) that includes the Fic domain shows autoadenylylation activity and adenylyl transfer onto Hela cell extract proteins as demonstrated by autoradiography on incubation with α-[32P]-ATP. Its crystal structure, determined to 2.9-Å resolution by the SeMet-SAD method, exhibits the canonical Fic fold including the HPFxxGNGRxxR signature motif with several elaborations in loop regions and an additional β-rich domain at the C-terminus. On crystal soaking with ATP/Mg2+, additional electron density indicated the presence of a PPi/Mg2+ moiety, the side product of the adenylylation reaction, in the anion binding nest of the signature motif. On the basis of this information and that of the recent structure of IbpA(Fic2) in complex with the eukaryotic target protein Cdc42, we present a detailed model for the ternary complex of Fic with the two substrates, ATP/Mg2+ and target tyrosine. The model is consistent with an in-line nucleophilic attack of the deprotonated side-chain hydroxyl group onto the α-phosphorus of the nucleotide to accomplish AMP transfer. Furthermore, a general, sequence-independent mechanism of target positioning through antiparallel β-strand interactions between enzyme and target is suggested. PMID:21213248

  1. Conjugative DNA transfer into human cells by the VirB/VirD4 type IV secretion system of the bacterial pathogen Bartonella henselae

    PubMed Central

    Schröder, Gunnar; Schuelein, Ralf; Quebatte, Maxime; Dehio, Christoph

    2011-01-01

    Bacterial type IV secretion systems (T4SS) mediate interbacterial conjugative DNA transfer and transkingdom protein transfer into eukaryotic host cells in bacterial pathogenesis. The sole bacterium known to naturally transfer DNA into eukaryotic host cells via a T4SS is the plant pathogen Agrobacterium tumefaciens. Here we demonstrate T4SS-mediated DNA transfer from a human bacterial pathogen into human cells. We show that the zoonotic pathogen Bartonella henselae can transfer a cryptic plasmid occurring in the bartonellae into the human endothelial cell line EA.hy926 via its T4SS VirB/VirD4. DNA transfer into EA.hy926 cells was demonstrated by using a reporter derivative of this Bartonella-specific mobilizable plasmid generated by insertion of a eukaryotic egfp-expression cassette. Fusion of the C-terminal secretion signal of the endogenous VirB/VirD4 protein substrate BepD with the plasmid-encoded DNA-transport protein Mob resulted in a 100-fold increased DNA transfer rate. Expression of the delivered egfp gene in EA.hy926 cells required cell division, suggesting that nuclear envelope breakdown may facilitate passive entry of the transferred ssDNA into the nucleus as prerequisite for complementary strand synthesis and transcription of the egfp gene. Addition of an eukaryotic neomycin phosphotransferase expression cassette to the reporter plasmid facilitated selection of stable transgenic EA.hy926 cell lines that display chromosomal integration of the transferred plasmid DNA. Our data suggest that T4SS-dependent DNA transfer into host cells may occur naturally during human infection with Bartonella and that these chronically infecting pathogens have potential for the engineering of in vivo gene-delivery vectors with applications in DNA vaccination and therapeutic gene therapy. PMID:21844337

  2. [Optimization of the preparation process for fusion protein Fv-LDP that composes lidamycin apoprotein and single-chain Fv antibody directed against type IV collagenase].

    PubMed

    Gao, Rui-Juan; Zhao, Chun-Yan; Li, Dian-Dong; Zhen, Yong-Su

    2013-10-01

    This study is to optimize the preparation process of fusion protein Fv-LDP which was expressed in the form of inclusion body and consisted of lidamycin apoprotein LDP and single-chain Fv antibody (scFv) directed against type IV collagenase. The preparation and the dissolution of inclusion body, the immobilized metal affinity chromatography of the target protein and the renaturization by stepwise dialysis were optimized by single-factor analysis or orthogonal design. In addition, the refolded fusion protein Fv-LDP was refined by Sephadex G-75 chromatography followed by fluorescence-activated cell sorter (FACS)-based saturation binding assay to measure its antigen-binding activity. After optimization of the process, the purity of fusion protein Fv-LDP existed in the inclusion body was 63.9% and the corresponding solubility was 95.7%; Under denaturing conditions, the purity of fusion protein Fv-LDP was more than 95% after the purification process. The percentage of monomeric fusion protein Fv-LDP was 60% after the refolding process, while it was further refined to 85% which was 5.6-fold higher than that of the initial refolding condition. The refined fusion protein Fv-LDP could bind to human lung adenocarcinoma PAa cells and human hepatoma BEL-7402 cells with the dissociation constants (Kd) of 0.176 micromol x L(-1) and 0.904 micromol x L(-1), respectively. The preparation process of fusion protein Fv-LDP has been successfully optimized, which provides the experimental basis for the production and future development of fusion protein Fv-LDP, and might serve as a relatively practical system for the preparation of other scFv-based proteins expressed in the form of inclusion body.

  3. Evolutionary Dynamics of Pathoadaptation Revealed by Three Independent Acquisitions of the VirB/D4 Type IV Secretion System in Bartonella

    PubMed Central

    Harms, Alexander; Segers, Francisca H.I.D.; Quebatte, Maxime; Mistl, Claudia; Manfredi, Pablo; Körner, Jonas; Chomel, Bruno B.; Kosoy, Michael; Maruyama, Soichi; Engel, Philipp

    2017-01-01

    The α-proteobacterial genus Bartonella comprises a group of ubiquitous mammalian pathogens that are studied as a model for the evolution of bacterial pathogenesis. Vast abundance of two particular phylogenetic lineages of Bartonella had been linked to enhanced host adaptability enabled by lineage-specific acquisition of a VirB/D4 type IV secretion system (T4SS) and parallel evolution of complex effector repertoires. However, the limited availability of genome sequences from one of those lineages as well as other, remote branches of Bartonella has so far hampered comprehensive understanding of how the VirB/D4 T4SS and its effectors called Beps have shaped Bartonella evolution. Here, we report the discovery of a third repertoire of Beps associated with the VirB/D4 T4SS of B. ancashensis, a novel human pathogen that lacks any signs of host adaptability and is only distantly related to the two species-rich lineages encoding a VirB/D4 T4SS. Furthermore, sequencing of ten new Bartonella isolates from under-sampled lineages enabled combined in silico analyses and wet lab experiments that suggest several parallel layers of functional diversification during evolution of the three Bep repertoires from a single ancestral effector. Our analyses show that the Beps of B. ancashensis share many features with the two other repertoires, but may represent a more ancestral state that has not yet unleashed the adaptive potential of such an effector set. We anticipate that the effectors of B. ancashensis will enable future studies to dissect the evolutionary history of Bartonella effectors and help unraveling the evolutionary forces underlying bacterial host adaptation. PMID:28338931

  4. High resolution electron microscopy of the Helicobacter pylori Cag type IV secretion system pili produced in varying conditions of iron availability.

    PubMed

    Haley, Kathryn Patricia; Blanz, Eric Joshua; Gaddy, Jennifer Angeline

    2014-11-21

    Helicobacter pylori is a helical-shaped, gram negative bacterium that colonizes the human gastric niche of half of the human population. H. pylori is the primary cause of gastric cancer, the second leading cause of cancer-related deaths worldwide. One virulence factor that has been associated with increased risk of gastric disease is the Cag-pathogenicity island, a 40-kb region within the chromosome of H. pylori that encodes a type IV secretion system and the cognate effector molecule, CagA. The Cag-T4SS is responsible for translocating CagA and peptidoglycan into host epithelial cells. The activity of the Cag-T4SS results in numerous changes in host cell biology including upregulation of cytokine expression, activation of proinflammatory pathways, cytoskeletal remodeling, and induction of oncogenic cell-signaling networks. The Cag-T4SS is a macromolecular machine comprised of sub-assembly components spanning the inner and outer membrane and extending outward from the cell into the extracellular space. The extracellular portion of the Cag-T4SS is referred to as the "pilus". Numerous studies have demonstrated that the Cag-T4SS pili are formed at the host-pathogen interface(. However, the environmental features that regulate the biogenesis of this important organelle remain largely obscure. Recently, we reported that conditions of low iron availability increased the Cag-T4SS activity and pilus biogenesis. Here we present an optimized protocol to grow H. pylori in varying conditions of iron availability prior to co-culture with human gastric epithelial cells. Further, we present the comprehensive protocol for visualization of the hyper-piliated phenotype exhibited in iron restricted conditions by high resolution scanning electron microscopy analyses.

  5. Development and Application of Pathovar-Specific Monoclonal Antibodies That Recognize the Lipopolysaccharide O Antigen and the Type IV Fimbriae of Xanthomonas hyacinthi

    PubMed Central

    van Doorn, J.; Ojanen-Reuhs, T.; Hollinger, T. C.; Reuhs, B. L.; Schots, A.; Boonekamp, P. M.; Oudega, B.

    1999-01-01

    The objective of this study was to develop a specific immunological diagnostic assay for yellow disease in hyacinths, using monoclonal antibodies (MAbs). Mice were immunized with a crude cell wall preparation (shear fraction) from Xanthomonas hyacinthi and with purified type IV fimbriae. Hybridomas were screened for a positive reaction with X. hyacinthi cells or fimbriae and for a negative reaction with X. translucens pv. graminis or Erwinia carotovora subsp. carotovora. Nine MAbs recognized fimbrial epitopes, as shown by immunoblotting, immunofluorescence, enzyme-linked immunosorbent assay (ELISA), and immunoelectron microscopy; however, three of these MAbs had weak cross-reactions with two X. translucens pathovars in immunoblotting experiments. Seven MAbs reacted with lipopolysaccharides and yielded a low-mobility ladder pattern on immunoblots. Subsequent analysis of MAb 2E5 showed that it specifically recognized an epitope on the O antigen, which was found to consist of rhamnose and fucose in a 2:1 molar ratio. The cross-reaction of MAb 2E5 with all X. hyacinthi strains tested showed that this O antigen is highly conserved within this species. MAb 1B10 also reacted with lipopolysaccharides. MAbs 2E5 and 1B10 were further tested in ELISA and immunoblotting experiments with cells and extracts from other pathogens. No cross-reaction was found with 27 other Xanthomonas pathovars tested or with 14 other bacterial species from other genera, such as Erwinia and Pseudomonas, indicating the high specificity of these antibodies. MAbs 2E5 and 1B10 were shown to be useful in ELISA for the detection of X. hyacinthi in infected hyacinths. PMID:10473431

  6. SDSS IV MaNGA: Deep observations of extra-planar, diffuse ionized gas around late-type galaxies from stacked IFU spectra

    NASA Astrophysics Data System (ADS)

    Jones, A.; Kauffmann, G.; D'Souza, R.; Bizyaev, D.; Law, D.; Haffner, L.; Bahé, Y.; Andrews, B.; Bershady, M.; Brownstein, J.; Bundy, K.; Cherinka, B.; Diamond-Stanic, A.; Drory, N.; Riffel, R. A.; Sánchez, S. F.; Thomas, D.; Wake, D.; Yan, R.; Zhang, K.

    2017-03-01

    We have conducted a study of extra-planar diffuse ionized gas using the first year data from the MaNGA IFU survey. We have stacked spectra from 49 edge-on, late-type galaxies as a function of distance from the midplane of the galaxy. With this technique we can detect the bright emission lines Hα, Hβ, [O ii]λλ3726, 3729, [O iii]λ5007, [N ii]λλ6549, 6584, and [S ii]λλ6717, 6731 out to about 4 kpc above the midplane. With 16 galaxies we can extend this analysis out to about 9 kpc, i.e. a distance of 2Re, vertically from the midplane. In the halo, the surface brightnesses of the [O ii] and Hα emission lines are comparable, unlike in the disk where Hα dominates. When we split the sample by specific star-formation rate, concentration index, and stellar mass, each subsample's emission line surface brightness profiles and ratios differ, indicating that extra-planar gas properties can vary. The emission line surface brightnesses of the gas around high specific star-formation rate galaxies are higher at all distances, and the line ratios are closer to ratios characteristic of H ii regions compared with low specific star-formation rate galaxies. The less concentrated and lower stellar mass samples exhibit line ratios that are more like H ii regions at larger distances than their more concentrated and higher stellar mass counterparts. The largest difference between different subsamples occurs when the galaxies are split by stellar mass. We additionally infer that gas far from the midplane in more massive galaxies has the highest temperatures and steepest radial temperature gradients based on their [N ii]/Hα and [O ii]/Hα ratios between the disk and the halo. SDSS IV.

  7. Development and application of pathovar-specific monoclonal antibodies that recognize the lipopolysaccharide O antigen and the type IV fimbriae of Xanthomonas hyacinthi

    SciTech Connect

    Doorn, J. van; Ojanen-Reuhs, T.; Hollinger, T.C.; Reuhs, B.L.; Schots, A.; Boonekamp, P.M.; Oudega, B.

    1999-09-01

    The objective of this study was to develop a specific immunological diagnostic assay for yellow disease in hyacinths, using monoclonal antibodies (MAbs). Mice were immunized with a crude cell wall preparation (shear fraction) from Xanthomonas hyacinthi and with purified type IV fimbriae. Hybridomas were screened for a positive reaction with X. hyacinthi cells or fimbriae and for a negative reaction with X. translucens pv. graminis or Erwinia carotovora subsp. carotovora. Nine MAbs recognized fimbrial epitopes, as shown by immunoblotting, immunofluorescence, enzyme-linked immunosorbent assay (ELISA), and immunoelectron microscopy; however, three of these MAbs had weak cross-reactions with two X. translucens pathovars in immunoblotting experiments. Seven MAbs reacted with lipopolysaccharides and yielded a low-mobility ladder pattern on immunoblots. Subsequent analysis of MAb 2E5 showed that it specifically recognized an epitope on the O antigen, which was found to consist of rhamnose and fucose in a 2:1 molar ratio. The cross-reaction of MAb 2E5 with all X. hyacinthi strains tested showed that this O antigen is highly conserved within this species. MAb 1B10 also reacted with lipopolysaccharides. MAbs 2E5 and 1B10 were further tested in ELISA and immunoblotting experiments with cells and extracts from other pathogens. No cross-reaction was found with 27 other Xanthomonas pathovars tested or with 14 other bacterial species from other genera, such as Erwinia and Pseudomonas, indicating the high specificity of these antibodies. MAbs 2E5 and 1B10 were shown to be useful in ELISA for the detection of X. hyacinthi in infected hyacinths.

  8. Structure of the human type IV collagen COL4A6 gene, which is mutated in Alport syndrome-associated leiomyomatosis

    SciTech Connect

    Zhang, Xu |; Zhou, Jing; Reeders, S.T.

    1996-05-01

    Basement membrane (type IV) collagen, a subfamily of the collagen protein family, is encoded by six distinct genes in mammals. Three of those, COL4A3, COL4A4, and COL4A5, are linked with Alport syndrome (hereditary nephritis). Patients with leimoyomatosis associated with Alport syndrome have been shown to have deletions in the 5{prime} end of the COL4A6 gene, in addition to having deletions in COL4A6. The human COL4A6 gene is reported to be 425 kb as determined by mapping of overlapping YAC clones by probes for its 5{prime} and 3{prime} ends. In the present study we describe the complete exon/intron size pattern of the human COL4A6 gene. The 12 {lambda} phage clones characterized in the study spanned a total of 110 kb, including 85 kb of the actual gene and 25 kb of flanking sequences. The overlapping clones contained all 46 exons of the gene and all introns, except for intron 2. Since the total size of the exons and all introns except for intron 2 is about 85 kb, intron 2 must be about 340 kb. All exons of the gene were assigned to EcoRI restriction fragments to facilitate analysis of the gene in patients with leiomyomatosis associated with Alport syndrome. The exon size pattern of COL4A6 is highly homologous with that of the human and mouse COL4A2 genes, with 27 of the 46 exons of COL4A6 being identical in size between the genes. 42 refs., 2 figs., 3 tabs.

  9. Feasibility and effectiveness of the implementation of a primary prevention programme for type 2 diabetes in routine primary care practice: a phase IV cluster randomised clinical trial

    PubMed Central

    2012-01-01

    Background The objective of this study is to perform an independent evaluation of the feasibility and effectiveness of an educational programme for the primary prevention of type 2 diabetes (DM2) in high risk populations in primary care settings, implanted within the Basque Health Service - Osakidetza. Methods/design This is a prospective phase IV cluster clinical trial conducted under routine conditions in 14 primary health care centres of Osakidetza, randomly assigned to an intervention or control group. We will recruit a total sample of 1089 individuals, aged between 45 and 70 years old, without diabetes but at high risk of developing the condition (Finnish Diabetes Risk Score, FINDRISC ≥ 14) and follow them up for 2 years. Primary health care nursing teams of the intervention centres will implement DE-PLAN, a structured educational intervention program focused on changing healthy lifestyles (diet and physical activity); while the patients in the control centres will receive the usual care for the prevention and treatment of DM2 currently provided in Osakidetza. The effectiveness attributable to the programme will be assessed by comparing the changes observed in patients exposed to the intervention and those in the control group, with respect to the risk of developing DM2 and lifestyle habits. In terms of feasibility, we will assess indicators of population coverage and programme implementation. Discussion The aim of this study is to provide the scientific basis for disseminate the programme to the remaining primary health centres in Osakidetza, as a novel way of addressing prevention of DM2. The study design will enable us to gather information on the effectiveness of the intervention as well as the feasibility of implementing it in routine practice. Trial registration ClinicalTrials.gov NCT01365013 PMID:23158830

  10. Substitution of Aspartate for glycine 1018 in the Type III procollagen (COL3AI) gene causes type IV Ehlers-Danlos Syndrome: The mutated allele is present in most blood leukocytes of the asymptomatic and mosaic mother

    SciTech Connect

    Kontusaari, S.; Tromp, G.; Kuivaniemi, H.; Prockop, D.J. ); Stolle, C. ); Pope, F.M.

    1992-09-01

    A proband with arterial ruptures and skin changes characteristic of the type IV variant of Ehlers-Danlos syndrome was found to have a single-base mutation in the type III procollagen gene, which converted the codon for glycine at amino position 1018 to a codon for aspartate. (Amino acid positions are numbered by the standard convention in which the first glycine of the triple-helical domain of an [alpha] chain is number 1. The numbers of positions in the [alpha]1(III) chains can be converted to positions in the human pro[alpha](III) chain by adding 167.). Nucleotide sequencing of overlapping PCR products in which the two alleles were distinguished demonstrated that the mutation of glycine 1018 was the only mutation that changed the primary structure of type III procollagen. The glycine substitution markedly decreased the amount of type III procollagen secreted into the medium by cultured skin fibroblasts from the proband. It is surprising that the same mutation was found in about 94% of the peripheral blood leukocytes from the proband's asymptomatic 72-year-old mother. Other tissues from the mother contained the mutated allele; it was present in 0%-100% of different samples of hair cells and in about 40% of cells from the oral epithelium. Therefore, the mother was a mosaic for the mutation. Since the mutated allele was present in cells derived from all three germ layers, the results indicated that the mutation arose by the late blastocyst stage of development. The results also indicate that assays of blood leukocytes do not always reveal mosaicism or predict phenotypic involvement of tissues, such as blood vessels, that are derived from the same embryonic cells as are leukocytes. 66 refs., 6 figs., 1 tab.

  11. Raman spectra of Cu{sub 2}B{sup II}C{sup IV}X{sub 4}{sup VI} magnetic quaternary semiconductor compounds with tetragonal stannite type structure

    SciTech Connect

    Rincón, C. Quintero, M.; Power, Ch.; Moreno, E.; Quintero, E.; Morocoima, M.; Henao, J. A.; Macías, M. A.

    2015-05-28

    A comparative study of the Raman spectra of Cu{sub 2}B{sup II}C{sup IV}S{sub 4}{sup VI} and Cu{sub 2}B{sup II}C{sup IV}Se{sub 4}{sup VI}(where B = Mn or Fe) magnetic quaternary semiconductor compounds with stannite-type structure (I4{sup ¯}2m) has been done. Most of the fourteen Raman lines expected for these materials were observed in the spectra. The two strongest lines observed have been assigned to the IR inactive A{sub 1}{sup 1} and A{sub 1}{sup 2} stannite modes that originated from the motion of the S or Se anion around the Cu and C{sup IV} cations remaining at rest. The shift in the frequency of these two lines of about 150 cm{sup −1} to lower energies observed in Cu{sub 2}B{sup II}C{sup IV}Se{sub 4}{sup VI} compounds as compared to those in Cu{sub 2}B{sup II}C{sup IV}S{sub 4}{sup VI} ones, can then be explained as due to the anion mass effect. Based on the fact that values of these frequencies depend mainly on anion mass and bond-stretching forces between nearest-neighbor atoms, the vibrational frequencies v{sup ¯}(A{sub 1}{sup 2}) and v{sup ¯}(A{sub 1}{sup 2}) of both modes for several Cu{sub 2}B{sup II}C{sup IV}X{sub 4}{sup VI} stannite compounds (where X = S, Se, or Te) very close to the experimental data reported for these materials were calculated from a simple model that relates these stretching forces to the anion-cation bond-distances.

  12. Sympathetic nervous system activity and anti-lipolytic response to iv-glucose load in subcutaneous adipose tissue of obese and obese type 2 diabetic subjects

    PubMed Central

    Schumann, Uwe; Jenkinson, Christopher P.; Alt, Andreas; Zügel, Martina; Steinacker, Jürgen M.; Flechtner-Mors, Marion

    2017-01-01

    The study aim was to investigate the effect of endogenous insulin release on lipolysis in subcutaneous adipose tissue after adrenergic stimulation in obese subjects diagnosed with type 2 diabetes (T2D). In 14 obese female T2D subjects, or 14 obese non-T2D controls, glycerol concentration was measured in response to the α1,2,ß-agonist norepinephrine, the α1-agonist norfenefrine and the ß2-agonist terbutaline (each 10−4 M), using the microdialysis technique. After 60 minutes of stimulation, an intravenous glucose load (0.5 g/kg lean body mass) was given. Local blood flow was monitored by means of the ethanol technique. Norepinephrine and norfenefrine induced a four and three fold rise in glycerol dialysate concentration (p<0.001, each), with a similar pattern in adipose tissue. Following agonist stimulation and glucose infusion, endogenous insulin release inhibited lipolysis in the presence of norepinephrine, which was more rapid and pronounced in healthy obese controls than in T2D subjects (p = 0.024 obese vs T2D subjects). Insulin-induced inhibition of lipolysis in the presence of norfenefrine was similar in all study participants. In the presence of terbutaline the lipolysis rate increased two fold until the effect of endogenous insulin (p<0.001). A similar insulin-induced decrease in lipolysis was observed for each of the norfenefrine groups and the terbutaline groups, respectively. Adipose tissue blood flow remained unchanged after the iv-glucose load. Both norepinephrine and norfenefrine diminished blood flow slightly, but insulin reversed this response (p<0.001 over the entire time). Terbutaline alone and terbutaline plus increased endogenous insulin augmented local blood flow (p<0.001 over the entire time). In conclusion, a difference in insulin-induced inhibition of lipolysis was observed in obese T2D subjects compared to obese healthy controls following modulation of sympathetic nervous system activity and is assumed to be due to ß1-adrenoceptor

  13. Bartonella henselae trimeric autotransporter adhesin BadA expression interferes with effector translocation by the VirB/D4 type IV secretion system.

    PubMed

    Lu, Yun-Yueh; Franz, Bettina; Truttmann, Matthias C; Riess, Tanja; Gay-Fraret, Jérémie; Faustmann, Marco; Kempf, Volkhard A J; Dehio, Christoph

    2013-05-01

    The Gram-negative, zoonotic pathogen Bartonella henselae is the aetiological agent of cat scratch disease, bacillary angiomatosis and peliosis hepatis in humans. Two pathogenicity factors of B. henselae - each displaying multiple functions in host cell interaction - have been characterized in greater detail: the trimeric autotransporter Bartonella adhesin A (BadA) and the type IV secretion system VirB/D4 (VirB/D4 T4SS). BadA mediates, e.g. binding to fibronectin (Fn), adherence to endothelial cells (ECs) and secretion of vascular endothelial growth factor (VEGF). VirB/D4 translocates several Bartonella effector proteins (Beps) into the cytoplasm of infected ECs, resulting, e.g. in uptake of bacterial aggregates via the invasome structure, inhibition of apoptosis and activation of a proangiogenic phenotype. Despite this knowledge of the individual activities of BadA or VirB/D4 it is unknown whether these major virulence factors affect each other in their specific activities. In this study, expression and function of BadA and VirB/D4 were analysed in a variety of clinical B. henselae isolates. Data revealed that most isolates have lost expression of either BadA or VirB/D4 during in vitro passages. However, the phenotypic effects of coexpression of both virulence factors was studied in one clinical isolate that was found to stably coexpress BadA and VirB/D4, as well as by ectopic expression of BadA in a strain expressing VirB/D4 but not BadA. BadA, which forms a dense layer on the bacterial surface, negatively affected VirB/D4-dependent Bep translocation and invasome formation by likely preventing close contact between the bacterial cell envelope and the host cell membrane. In contrast, BadA-dependent Fn binding, adhesion to ECs and VEGF secretion were not affected by a functional VirB/D4 T4SS. The obtained data imply that the essential virulence factors BadA and VirB/D4 are likely differentially expressed during different stages of the infection cycle of

  14. Intelligent Virtual Station (IVS)

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The Intelligent Virtual Station (IVS) is enabling the integration of design, training, and operations capabilities into an intelligent virtual station for the International Space Station (ISS). A viewgraph of the IVS Remote Server is presented.

  15. Ovarian Cancer Stage IV

    MedlinePlus

    ... hyphen, e.g. -historical Searches are case-insensitive Ovarian Cancer Stage IV Add to My Pictures View /Download : ... 1200x1335 View Download Large: 2400x2670 View Download Title: Ovarian Cancer Stage IV Description: Drawing of stage IV shows ...

  16. Cellular distribution of transforming growth factor-beta 1 and procollagen types I, III, and IV transcripts in carbon tetrachloride-induced rat liver fibrosis.

    PubMed Central

    Nakatsukasa, H; Nagy, P; Evarts, R P; Hsia, C C; Marsden, E; Thorgeirsson, S S

    1990-01-01

    The cellular distribution and temporal expression of transcripts from transforming growth factor-beta 1 (TGF-beta 1) and procollagen alpha 1(I), alpha 1(III), and alpha 1(IV) genes were studied in carbon tetrachloride (CCl4)-induced rat liver fibrosis by using in situ hybridization technique. During the fibrotic process, TGF-beta 1 and procollagen genes were similarly and predominantly expressed in Desmin-positive perisinusoidal cells (e.g., fat-storing cells and myofibroblasts) and fibroblasts and their expression continued to be higher than those observed in control rats. These transcripts were also observed in inflammatory cells mainly granulocytes and macrophage-like cells at the early stages of liver fibrosis. The production of extracellular matrix along small blood vessels and fibrous septa coincided with the expression of these genes. Expression of TGF-beta 1 and procollagen genes were not detected in hepatocytes throughout the experiment. No significant differences in cellular distribution or time course of gene expression among procollagen alpha 1(I), alpha 1(III), and alpha 1(IV) were observed. Desmin-positive perisinusoidal cells and fibroblasts appeared to play the principal role in synthesis of collagens in CCl4-induced hepatic fibrosis. The simultaneous expression of TGF-beta 1 and procollagen genes in mesenchymal cells, including Desmin-positive perisinusoidal cells, during hepatic fibrosis suggests the possibility that TGF-beta 1 may have an important role in the production of fibrosis. Images PMID:1693377

  17. GDP (Gemcitabine, Dexamethasone, and Cisplatin) Is Highly Effective and Well-Tolerated for Newly Diagnosed Stage IV and Relapsed/Refractory Extranodal Natural Killer/T-Cell Lymphoma, Nasal Type

    PubMed Central

    Wang, Jing-jing; Dong, Mei; He, Xiao-hui; Li, Ye-xiong; Wang, Wei-hu; Liu, Peng; Yang, Jian-liang; Gui, Lin; Zhang, Chang-gong; Yang, Sheng; Zhou, Sheng-yu; Shi, Yuan-kai

    2016-01-01

    Abstract This study was conducted to evaluate the effectiveness and tolerance of GDP (gemcitabine, dexamethasone, and cisplatin) regimen in patients with newly diagnosed stage IV and relapsed/refractory extranodal natural killer/T-cell lymphoma, nasal type (ENKTL). The study enrolled 41 ENKTL patients who received GDP regimen at the Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College between January 2008 and January 2015. The disease status was newly diagnosed stage IV in 15 patients and relapsed/refractory in 26 patients. The median number of cycles of chemotherapy per patient was 6 (range, 2–8 cycles). The overall response rate and complete-remission rate were 83.0% (34/41) and 41.5% (17/41), respectively. After a median follow-up of 16.2 months, 1-year progression-free survival rate and 1-year overall survival rate for the whole cohort were 54.5% and 72.7%. Grade 3 to 4 adverse events included neutropenia (34.1%), thrombocytopenia (19.5%), and anemia (14.6%). Our study has suggested high efficacy and low toxicity profile of GDP regimen in patients with newly diagnosed stage IV and relapsed/refractory ENKTL. PMID:26871836

  18. Level III and IV Ecoregions by State

    EPA Pesticide Factsheets

    Information and links to downloadable maps and datasets for Level III and IV ecoregions, listed by state. Ecoregions are areas of general similarity in the type, quality, and quantity of environmental resources.

  19. Energy levels and lifetimes of Nd IV, Pm IV, Sm IV, and Eu IV

    SciTech Connect

    Dzuba, V. A.; Safronova, U. I.; Johnson, W. R.

    2003-09-01

    To address the shortage of experimental data for electron spectra of triply ionized rare-earth elements we have calculated energy levels and lifetimes of 4f{sup n+1} and 4f{sup n}5d configurations of Nd IV (n=2), Pm IV (n=3), Sm IV (n=4), and Eu IV (n=5) using Hartree-Fock and configuration-interaction methods. To control the accuracy of our calculations we also performed similar calculations for Pr III, Nd III, and Sm III, for which experimental data are available. The results are important, in particular, for physics of magnetic garnets.

  20. Legionella pneumophila Type IV Effectors YlfA and YlfB Are SNARE-Like Proteins that Form Homo- and Heteromeric Complexes and Enhance the Efficiency of Vacuole Remodeling

    PubMed Central

    Campodonico, Eva M.; Roy, Craig R.; Ninio, Shira

    2016-01-01

    Legionella pneumophila is a Gram-negative bacterium that can colonize both freshwater protozoa and human alveolar macrophages, the latter infection resulting in Legionnaires’ disease. The intracellular lifecycle of L. pneumophila requires extensive manipulation of its host cell, which is carried out by effector proteins that are translocated into the host cell through the Dot/Icm type IV secretion system. This study focuses on a pair of highly similar type IV substrates called YlfA/LegC7 and YlfB/LegC2 that were initially identified in a screen for proteins that cause growth inhibition in yeast. Analysis of truncation mutants revealed that the hydrophobic residues in the Ylf amino termini were required for localization of each protein to the membranes of host cells. Central and carboxy terminal coiled coil domains were found to mediate binding of YlfA and YlfB to themselves and to each other. In vivo, a ΔylfA ΔylfB double mutant strain of L. pneumophila was shown to be defective in establishing a vacuole that supports bacterial replication. This phenotype was subsequently correlated with a decrease in the association of endoplasmic reticulum (ER)-derived vesicles with vacuoles containing ΔylfA ΔylfB mutant bacteria. These data suggest that the Ylf proteins are membrane-associated effectors that enhance remodeling of the L. pneumophila -containing vacuole by promoting association and possibly fusion of ER-derived membrane vesicles with the bacterial compartment. PMID:27459495

  1. Comparison of the DSM-IV Combined and Inattentive Types of ADHD in a School-Based Sample of Latino/Hispanic Children

    ERIC Educational Resources Information Center

    Bauermeister, Jose J.; Matos, Maribel; Reina, Graciela; Salas, Carmen C.; Martinez, Jose V.; Cumba, Eduardo; Barkley, Russell A.

    2005-01-01

    Background: The aim of this investigation was to examine the construct validity and distinctiveness of the inattentive type (IT) and combined type (CT) of Attention-Deficit/Hyperactivity Disorder (ADHD) in a Latino/Hispanic sample. Method: A comprehensive assessment was conducted with a clinically diagnosed school-based sample of 98 children aged…

  2. Congenital type IV glycogenosis: the spectrum of pleomorphic polyglucosan bodies in muscle, nerve, and spinal cord with two novel mutations in the GBE1 gene.

    PubMed

    Nolte, Kay W; Janecke, Andreas R; Vorgerd, Matthias; Weis, Joachim; Schröder, J Michael

    2008-11-01

    A diagnosis of GSD-IV was established in three premature, floppy infants based on characteristic, however unusually pleomorphic polyglucosan bodies at the electron microscopic level, glycogen branching enzyme deficiency in two cases, and the identification of GBE1 mutations in two cases. Pleomorphic polyglucosan bodies in muscle fibers and macrophages, and less severe in Schwann cells and microglial cells were noted. Most of the inclusions were granular and membrane-bound; others had an irregular contour, were more electron dense and were not membrane bound, or homogenous ('hyaline'). A paracrystalline pattern of granules was repeatedly noted showing a periodicity of about 10 nm with an angle of about 60 degrees or 120 degrees at sites of changing linear orientation. Malteser crosses were noted under polarized light in the larger inclusions. Some inclusions were PAS positive and others were not. Severely atrophic muscle fibers without inclusions, but with depletion of myofibrils in the plane of section studied indicated the devastating myopathic nature of the disease. Schwann cells and peripheral axons were less severely affected as was the spinal cord. Two novel protein-truncating mutations (c.1077insT, p.V359fsX16; g.101517_127067del25550insCAGTACTAA, DelExon4-7) were identified in these families. The present findings extend previous studies indicating that truncating GBE1 mutations cause a spectrum of severe diseases ranging from generalized intrauterine hydrops to fatal perinatal hypotonia and fatal cardiomyopathy in the first months of life.

  3. Silicon(IV) phthalocyanines substituted axially with different nucleoside moieties. Effects of nucleoside type on the photosensitizing efficiencies and in vitro photodynamic activities.

    PubMed

    Zheng, Bi-Yuan; Shen, Xiao-Min; Zhao, Dong-Mei; Cai, Yi-Bin; Ke, Mei-Rong; Huang, Jian-Dong

    2016-06-01

    A series of new silicon(IV) phthalocyanines (SiPcs) di-substituted axially with different nucleoside moieties have been synthesized and evaluated for their singlet oxygen quantum yields (ΦΔ) and in vitro photodynamic activities. The adenosine-substituted SiPc shows a lower photosensitizing efficiency (ΦΔ=0.35) than the uridine- and cytidine-substituted analogs (ΦΔ=0.42-0.44), while the guanosine-substituted SiPc exhibits a weakest singlet oxygen generation efficiency with a ΦΔ value down to 0.03. On the other hand, replacing axial adenosines with chloro-modified adenosines and purines can result in the increase of photogenerating singlet oxygen efficiencies of SiPcs. The formed SiPcs 1 and 2, which contain monochloro-modified adenosines and dichloro-modified purines respectively, appear as efficient photosensitizers with ΦΔ of 0.42-0.44. Both compounds 1 and 2 present high photocytotoxicities against HepG2 and BGC823 cancer cells with IC50 values ranging from 9nM to 33nM. The photocytotoxicities of these two compounds are remarkably higher than the well-known anticancer photosensitizer, chlorin e6 (IC50=752nM against HepG2 cells) in the same condition. As revealed by confocal microscopy, for both cell lines, compound 1 can essentially bind to mitochondria, while compound 2 is just partially localized in mitochondria. In addition, the two compounds induce cell death of HepG2 cells likely through apoptosis.

  4. Nuclear magnetic resonance (NMR) solution structure, dynamics, and binding properties of the kringle IV type 8 module of apolipoprotein(a).

    PubMed

    Chitayat, Seth; Kanelis, Voula; Koschinsky, Marlys L; Smith, Steven P

    2007-02-20

    The plasma lipoprotein lipoprotein(a) [Lp(a)] comprises a low-density lipoprotein (LDL)-like particle covalently attached to the glycoprotein apolipoprotein(a) [apo(a)]. Apo(a) consists of multiple tandem repeating kringle modules, similar to plasminogen kringle IV (designated KIV1-KIV10), followed by modules homologous to the kringle V module and protease domain of plasminogen. The apo(a) KIV modules have been classified on the basis of their binding affinity for lysine and lysine analogues. The strong lysine-binding apo(a) KIV10 module mediates lysine-dependent interactions with fibrin and cell-surface receptors. Weak lysine-binding apo(a) KIV7 and KIV8 modules display a 2-3-fold difference in lysine affinity and play a direct role in the noncovalent step in Lp(a) assembly through binding to unique lysine-containing sequences in apolipoproteinB-100 (apoB-100). The present study describes the nuclear magnetic resonance solution structure of apo(a) KIV8 and its solution dynamics properties, the first for an apo(a) kringle module, and compares the effects of epsilon-aminocaproic acid (epsilon-ACA) binding on the backbone and side-chain conformation of KIV7 and KIV8 on a per residue basis. Apo(a) KIV8 adopts a well-ordered structure that shares the general tri-loop kringle topology with apo(a) KIV6, KIV7, and KIV10. Mapping of epsilon-ACA-induced chemical-shift changes on KIV7 and KIV8 indicate that the same residues are affected, despite a 2-3-fold difference in epsilon-ACA affinity. A unique loop conformation within KIV8, involving hydrophobic interactions with Tyr40, affects the positioning of Arg35 relative to the lysine-binding site (LBS). A difference in the orientation of the aromatic side chains comprising the hydrophobic center of the LBS in KIV8 decreases the size of the hydrophobic cleft compared to other apo(a) KIV modules. An exposed hydrophobic patch contiguous with the LBS in KIV8 and not conserved in other weak lysine-binding apo(a) kringle modules

  5. Alternative Agents in Type 1 Diabetes in Addition to Insulin Therapy: Metformin, Alpha-Glucosidase Inhibitors, Pioglitazone, GLP-1 Agonists, DPP-IV Inhibitors, and SGLT-2 Inhibitors.

    PubMed

    DeGeeter, Michelle; Williamson, Bobbie

    2016-04-01

    Insulin is the mainstay of current treatment for patients with type 1 diabetes mellitus (T1DM). Due to increasing insulin resistance, insulin doses are often continually increased, which may result in weight gain for patients. Medications currently approved for the treatment of type 2 diabetes offer varying mechanisms of action that can help to reduce insulin resistance and prevent or deter weight gain. A MEDLINE search was conducted to review literature evaluating the use of metformin, alpha-glucosidase inhibitors, pioglitazone, glucagon-like peptide 1 agonists, dipeptidyl peptidase, and sodium-dependent glucose transporter 2 inhibitors, in patients with T1DM. Varying results were found with some benefits including reductions in hemoglobin A1c, decreased insulin doses, and favorable effects on weight. Of significance, a common fear of utilizing multiple therapies for diabetes treatment is the risk of hypoglycemia, and this review displayed limited evidence of hypoglycemia with multiple agents.

  6. The MASSIVE Survey. IV. The X-ray Halos of the Most Massive Early-type Galaxies in the Nearby Universe

    NASA Astrophysics Data System (ADS)

    Goulding, Andy D.; Greene, Jenny E.; Ma, Chung-Pei; Veale, Melanie; Bogdan, Akos; Nyland, Kristina; Blakeslee, John P.; McConnell, Nicholas J.; Thomas, Jens

    2016-08-01

    Studies of the physical properties of local elliptical galaxies are shedding new light on galaxy formation. Here we present the hot-gas properties of 33 early-type systems within the MASSIVE galaxy survey that have archival Chandra X-ray observations, and we use these data to derive X-ray luminosities ({L}{{X,gas}}) and plasma temperatures ({T}{{gas}}) for the diffuse gas components. We combine this with the {{ATLAS}}{{3D}} survey to investigate the X-ray-optical properties of a statistically significant sample of early-type galaxies across a wide range of environments. When X-ray measurements are performed consistently in apertures set by the galaxy stellar content, we deduce that all early types (independent of galaxy mass, environment, and rotational support) follow a universal scaling law such that {L}{{X,gas}}\\propto {T}{{gas}}˜ 4.5. We further demonstrate that the scatter in {L}{{X,gas}} around both K-band luminosity (L K ) and the galaxy stellar velocity dispersion ({σ }e) is primarily driven by {T}{{gas}}, with no clear trends with halo mass, radio power, or angular momentum of the stars. It is not trivial to tie the gas origin directly to either stellar mass or galaxy potential. Indeed, our data require a steeper relation between {L}{{X,gas}},{L}K, and {σ }e than predicted by standard mass-loss models. Finally, we find that {T}{{gas}} is set by the galaxy potential inside the optical effective radius. We conclude that within the innermost 10-30 kpc region, early types maintain pressure-supported hot gas, with a minimum {T}{{gas}} set by the virial temperature, but the majority show evidence for additional heating.

  7. Coxiella burnetii Employs the Dot/Icm Type IV Secretion System to Modulate Host NF-κB/RelA Activation

    PubMed Central

    Mahapatra, Saugata; Gallaher, Brandi; Smith, Sydni Caet; Graham, Joseph G.; Voth, Daniel E.; Shaw, Edward I.

    2016-01-01

    Coxiella burnetii is the causative agent of Q fever and an obligate intracellular pathogen in nature that survives and grows in a parasitophorous vacuole (PV) within eukaryotic host cells. C. burnetii promotes intracellular survival by subverting apoptotic and pro-inflammatory signaling pathways that are typically regulated by nuclear transcription factor-κB (NF-κB). We and others have demonstrated that C. burnetii NMII proteins inhibit expression of pro-inflammatory cytokines and induce expression of anti-apoptotic genes during infection. Here, we demonstrate that C. burnetii promotes intracellular survival by modulating NF-κB subunit p65 (RelA) phosphorylation, and thus activation, in a Type Four B Secretion System (T4BSS)-dependent manner. Immunoblot analysis of RelA phosphorylated at serine-536 demonstrated that C. burnetii increases NF-κB activation via the canonical pathway. However, RelA phosphorylation levels were even higher in infected cells where bacterial protein or mRNA synthesis was inhibited. Importantly, we demonstrate that inhibition of RelA phosphorylation impairs PV formation and C. burnetii growth. We found that a T4BSS-defective mutant (CbΔdotA) elicited phosphorylated RelA levels similar to those of wild type C. burnetii infection treated with Chloramphenicol. Moreover, cells infected with CbΔdotA or wild type C. burnetii treated with Chloramphenicol showed similar levels of GFP-RelA nuclear localization, and significantly increased localization compared to wild type C. burnetii infection. These data indicate that without de novo protein synthesis and a functional T4BSS, C. burnetii is unable to modulate NF-κB activation, which is crucial for optimal intracellular growth. PMID:28066723

  8. A Geobacter sulfurreducens strain expressing pseudomonas aeruginosa type IV pili localizes OmcS on pili but is deficient in Fe(III) oxide reduction and current production.

    PubMed

    Liu, Xing; Tremblay, Pier-Luc; Malvankar, Nikhil S; Nevin, Kelly P; Lovley, Derek R; Vargas, Madeline

    2014-02-01

    The conductive pili of Geobacter species play an important role in electron transfer to Fe(III) oxides, in long-range electron transport through current-producing biofilms, and in direct interspecies electron transfer. Although multiple lines of evidence have indicated that the pili of Geobacter sulfurreducens have a metal-like conductivity, independent of the presence of c-type cytochromes, this claim is still controversial. In order to further investigate this phenomenon, a strain of G. sulfurreducens, designated strain PA, was constructed in which the gene for the native PilA, the structural pilin protein, was replaced with the PilA gene of Pseudomonas aeruginosa PAO1. Strain PA expressed and properly assembled P. aeruginosa PilA subunits into pili and exhibited a profile of outer surface c-type cytochromes similar to that of a control strain expressing the G. sulfurreducens PilA. Surprisingly, the strain PA pili were decorated with the c-type cytochrome OmcS in a manner similar to the control strain. However, the strain PA pili were 14-fold less conductive than the pili of the control strain, and strain PA was severely impaired in Fe(III) oxide reduction and current production. These results demonstrate that the presence of OmcS on pili is not sufficient to confer conductivity to pili and suggest that there are unique structural features of the G. sulfurreducens PilA that are necessary for conductivity.

  9. A Geobacter sulfurreducens Strain Expressing Pseudomonas aeruginosa Type IV Pili Localizes OmcS on Pili but Is Deficient in Fe(III) Oxide Reduction and Current Production

    PubMed Central

    Liu, Xing; Tremblay, Pier-Luc; Malvankar, Nikhil S.; Nevin, Kelly P.; Vargas, Madeline

    2014-01-01

    The conductive pili of Geobacter species play an important role in electron transfer to Fe(III) oxides, in long-range electron transport through current-producing biofilms, and in direct interspecies electron transfer. Although multiple lines of evidence have indicated that the pili of Geobacter sulfurreducens have a metal-like conductivity, independent of the presence of c-type cytochromes, this claim is still controversial. In order to further investigate this phenomenon, a strain of G. sulfurreducens, designated strain PA, was constructed in which the gene for the native PilA, the structural pilin protein, was replaced with the PilA gene of Pseudomonas aeruginosa PAO1. Strain PA expressed and properly assembled P. aeruginosa PilA subunits into pili and exhibited a profile of outer surface c-type cytochromes similar to that of a control strain expressing the G. sulfurreducens PilA. Surprisingly, the strain PA pili were decorated with the c-type cytochrome OmcS in a manner similar to the control strain. However, the strain PA pili were 14-fold less conductive than the pili of the control strain, and strain PA was severely impaired in Fe(III) oxide reduction and current production. These results demonstrate that the presence of OmcS on pili is not sufficient to confer conductivity to pili and suggest that there are unique structural features of the G. sulfurreducens PilA that are necessary for conductivity. PMID:24296506

  10. Calcium binding properties of the Kingella kingae PilC1 and PilC2 proteins have differential effects on type IV pilus-mediated adherence and twitching motility.

    PubMed

    Porsch, Eric A; Johnson, Michael D L; Broadnax, Angela D; Garrett, Christopher K; Redinbo, Matthew R; St Geme, Joseph W

    2013-02-01

    Kingella kingae is an emerging bacterial pathogen that is being recognized increasingly as an important etiology of septic arthritis, osteomyelitis, and bacteremia, especially in young children. The pathogenesis of K. kingae disease begins with bacterial adherence to respiratory epithelium, which is dependent on type IV pili and is influenced by two PilC-like proteins called PilC1 and PilC2. Production of either PilC1 or PilC2 is necessary for K. kingae piliation and bacterial adherence. In this study, we set out to further investigate the role of PilC1 and PilC2 in type IV pilus-associated phenotypes. We found that PilC1 contains a functional 9-amino-acid calcium-binding (Ca-binding) site with homology to the Pseudomonas aeruginosa PilY1 Ca-binding site and that PilC2 contains a functional 12-amino-acid Ca-binding site with homology to the human calmodulin Ca-binding site. Using targeted mutagenesis to disrupt the Ca-binding sites, we demonstrated that the PilC1 and PilC2 Ca-binding sites are dispensable for piliation. Interestingly, we showed that the PilC1 site is necessary for twitching motility and adherence to Chang epithelial cells, while the PilC2 site has only a minor influence on twitching motility and no influence on adherence. These findings establish key differences in PilC1 and PilC2 function in K. kingae and provide insights into the biology of the PilC-like family of proteins.

  11. Calcium Binding Properties of the Kingella kingae PilC1 and PilC2 Proteins Have Differential Effects on Type IV Pilus-Mediated Adherence and Twitching Motility

    PubMed Central

    Porsch, Eric A.; Johnson, Michael D. L.; Broadnax, Angela D.; Garrett, Christopher K.; Redinbo, Matthew R.

    2013-01-01

    Kingella kingae is an emerging bacterial pathogen that is being recognized increasingly as an important etiology of septic arthritis, osteomyelitis, and bacteremia, especially in young children. The pathogenesis of K. kingae disease begins with bacterial adherence to respiratory epithelium, which is dependent on type IV pili and is influenced by two PilC-like proteins called PilC1 and PilC2. Production of either PilC1 or PilC2 is necessary for K. kingae piliation and bacterial adherence. In this study, we set out to further investigate the role of PilC1 and PilC2 in type IV pilus-associated phenotypes. We found that PilC1 contains a functional 9-amino-acid calcium-binding (Ca-binding) site with homology to the Pseudomonas aeruginosa PilY1 Ca-binding site and that PilC2 contains a functional 12-amino-acid Ca-binding site with homology to the human calmodulin Ca-binding site. Using targeted mutagenesis to disrupt the Ca-binding sites, we demonstrated that the PilC1 and PilC2 Ca-binding sites are dispensable for piliation. Interestingly, we showed that the PilC1 site is necessary for twitching motility and adherence to Chang epithelial cells, while the PilC2 site has only a minor influence on twitching motility and no influence on adherence. These findings establish key differences in PilC1 and PilC2 function in K. kingae and provide insights into the biology of the PilC-like family of proteins. PMID:23243304

  12. IV treatment at home

    MedlinePlus

    ... venous catheter - home; Port - home; PICC line - home; Infusion therapy - home; Home health care - IV treatment ... is given quickly, all at once. A slow infusion, which means the medicine is given slowly over ...

  13. GCF Mark IV development

    NASA Technical Reports Server (NTRS)

    Mortensen, L. O.

    1982-01-01

    The Mark IV ground communication facility (GCF) as it is implemented to support the network consolidation program is reviewed. Changes in the GCF are made in the area of increased capacity. Common carrier circuits are the medium for data transfer. The message multiplexing in the Mark IV era differs from the Mark III era, in that all multiplexing is done in a GCF computer under GCF software control, which is similar to the multiplexing currently done in the high speed data subsystem.

  14. Type IV(B) pili are required for invasion but not for adhesion of Salmonella enterica serovar Typhi into BHK epithelial cells in a cystic fibrosis transmembrane conductance regulator-independent manner.

    PubMed

    Bravo, Denisse; Blondel, Carlos J; Hoare, Anilei; Leyton, Lisette; Valvano, Miguel A; Contreras, Inés

    2011-11-01

    The cystic fibrosis transmembrane conductance regulator (CFTR) has been proposed as an epithelial cell receptor for the entry of Salmonella Typhi but not Salmonella Typhimurium. The bacterial ligand recognized by CFTR is thought to reside either in the S. Typhi lipopolysaccharide core region or in the type IV pili. Here, we assessed the ability of virulent strains of S. Typhi and S. Typhimurium to adhere to and invade BHK epithelial cells expressing either the wild-type CFTR protein or the ∆F508 CFTR mutant. Both S. Typhi and S. Typhimurium invaded the epithelial cells in a CFTR-independent fashion. Furthermore and also in a CFTR-independent manner, a S. Typhi pilS mutant adhered normally to BHK cells but displayed a 50% reduction in invasion as compared to wild-type bacteria. Immunofluorescence microscopy revealed that bacteria and CFTR do not colocalize at the epithelial cell surface. Together, our results strongly argue against the established dogma that CFTR is a receptor for entry of Salmonella to epithelial cells.

  15. DISSECTING THE RED SEQUENCE. IV. THE ROLE OF TRUNCATION IN THE TWO-DIMENSIONAL FAMILY OF EARLY-TYPE GALAXY STAR FORMATION HISTORIES

    SciTech Connect

    Graves, Genevieve J.; Faber, S. M.

    2010-09-20

    In the three-dimensional parameter space defined by velocity dispersion ({sigma}), effective radius (R{sub e}), and effective surface brightness (I{sub e}), early-type galaxies are observed to populate a two-dimensional fundamental plane (FP) with finite thickness. In Paper III of this series, we showed that the thickness of the FP is predominantly due to variations in the stellar mass surface density ({Sigma}{sub *}) inside the effective radius R{sub e} . These variations represent differences in the dark matter fraction inside R{sub e} (or possibly differences in the initial mass function) from galaxy to galaxy. This means that galaxies do not wind up below the FP at lower surface brightness due to the passive fading of their stellar populations; they are structurally different. Here, we show that these variations in {Sigma}{sub *} at fixed dynamical mass (M{sub dyn}) are linked to differences in the galaxy stellar populations, and therefore to differences in their star formation histories. We demonstrate that the ensemble of stellar population and {Sigma}{sub *} variations through the FP thickness can be explained by a model in which early-type galaxies at fixed M{sub dyn} have their star formation truncated at different times. The thickness of the FP can therefore be interpreted as a sequence of truncation times. Galaxies below the FP have earlier truncation times for a given M{sub dyn}, resulting in lower {Sigma}{sub *}, older ages, lower metallicities in both [Fe/H] and [Mg/H], and higher [Mg/Fe]. We show that this model is quantitatively consistent with simple expectations for chemical enrichment in galaxies. We also present fitting functions for luminosity-weighted age, [Fe/H], [Mg/H], and [Mg/Fe] as functions of the FP parameters {sigma}, R{sub e} , and I{sub e} . These provide a new tool for estimating the stellar population properties of quiescent early-type galaxies for which high-quality spectra are not available.

  16. Impact of Baseline BMI on Glycemic Control and Weight Change with Metformin Monotherapy in Chinese Type 2 Diabetes Patients: Phase IV Open-Label Trial

    PubMed Central

    Ji, Linong; Li, Hongmei; Guo, Xiaohui; Li, Yan; Hu, Renming; Zhu, Zhengying

    2013-01-01

    Background Differences exist between treatment recommendations regarding the choice of metformin as first-line therapy for type 2 diabetes patients according to body mass index (BMI). This study compared the efficacy of metformin monotherapy among normal-weight, overweight, and obese patients with newly diagnosed type 2 diabetes. Methods In this prospective, multicenter, open-label study in China, patients aged 23–77 years were enrolled 1∶1:1 according to baseline BMI: normal-weight (BMI 18.5−23.9 kg/m2; n = 125); overweight (BMI 24.0−27.9 kg/m2; n = 122) or obese (BMI ≥28 kg/m2; n = 124). Extended-release metformin was administered for 16 weeks (500 mg/day, up-titrated weekly to a maximum 2,000 mg/day). The primary efficacy endpoint was the effect of baseline BMI on glycemic control with metformin monotherapy, measured as the change from baseline in glycosylated hemoglobin (HbA1c) at week 16 compared among BMI groups using ANCOVA. Other endpoints included comparisons of metformin’s effects on fasting plasma glucose (FPG), lipid levels and body weight. Results Mean HbA1c decreases at week 16, adjusted for baseline values, were –1.84%, –1.78% and –1.78% in normal-weight, overweight and obese patients, (P = 0.664); body weight decreased by 2.4%, 3.9% and 3.5%, respectively. FPG levels decreased similarly over time in all BMI groups (P = 0.461) and changes from baseline in high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) did not differ significantly among BMI groups at week 16 (P = 0.143 and 0.451, respectively). Conclusions Baseline BMI had no impact on glycemic control, weight change or other efficacy measures with metformin monotherapy. These data suggest that normal-weight type 2 diabetes patients would derive the same benefits from first-line treatment with metformin as overweight and obese patients, and are not at increased risk of excess weight loss. Trial Registration

  17. Population studies in groups and clusters of galaxies. IV - Comparison of the luminosity functions and morphological-type distributions in seven nearby groups

    NASA Technical Reports Server (NTRS)

    Ferguson, Henry C.; Sandage, Allan

    1991-01-01

    Published observational data on the Leo, Dorado, NGC 1400, NGC 5044, Antlia, Fornax, and Virgo groups of galaxies are analyzed in terms of the luminosity functions and morphological types of their members. The data sets employed are characterized, and the results are presented in extensive tables and graphs and discussed in detail. While the fractions of early and late galaxies in the groups are similar, the ratio of dwarfs to giants (D/G) in the early galaxies varies monotonically with the richness of the cluster, leading to artificial flattening at the faint end of the total luminosity function in environments with low D/G. The luminosity function for dwarfs in all environments is found to have a slope of about -1.3.

  18. Population studies in groups and clusters of galaxies. IV. Comparison of the luminosity functions and morphological-type distributions in seven nearby groups

    SciTech Connect

    Ferguson, H.C.; Sandage, A. Observatories of the Carnegie Institution, Pasadena, CA Space Telescope Science Institute, Baltimore, MD )

    1991-03-01

    Published observational data on the Leo, Dorado, NGC 1400, NGC 5044, Antlia, Fornax, and Virgo groups of galaxies are analyzed in terms of the luminosity functions and morphological types of their members. The data sets employed are characterized, and the results are presented in extensive tables and graphs and discussed in detail. While the fractions of early and late galaxies in the groups are similar, the ratio of dwarfs to giants (D/G) in the early galaxies varies monotonically with the richness of the cluster, leading to artificial flattening at the faint end of the total luminosity function in environments with low D/G. The luminosity function for dwarfs in all environments is found to have a slope of about -1.3. 54 refs.

  19. The Tolman Surface Brightness Test for the Reality of the Expansion. IV. A Measurement of the Tolman Signal and the Luminosity Evolution of Early-Type Galaxies

    NASA Astrophysics Data System (ADS)

    Lubin, Lori M.; Sandage, Allan

    2001-09-01

    We review a sample of the early literature in which the reality of the expansion is discussed. Hubble's reluctance, even as late as 1953, to accept the expansion as real is explained as due to his use of equations for distances and absolute magnitudes of redshifted galaxies that do not conform to the modern Mattig equations of the standard model. The Tolman surface brightness test, once the only known test for the reality of the expansion, is contrasted with three other modern tests. These are (1) the time dilation in Type Ia supernovae light curves, (2) the temperature of the relic radiation as a function of redshift, and (3) the surface brightness normalization of the Planckian shape of the relic radiation. We search for the Tolman surface brightness depression with redshift using the Hubble Space Telescope (HST) data from Paper III for 34 early-type galaxies from the three clusters Cl 1324+3011 (z=0.76), Cl 1604+4304 (z=0.90), and Cl 1604+4321 (z=0.92). Depressions of the surface brightness relative to the zero-redshift fiducial lines in the mean surface brightness-logarithm of the linear radius diagrams of Paper I are found for all three clusters. Expressed as the exponent, n, in 2.5log(1+z)n mag, the value of n averaged over Petrosian radii of η=1.7 and η=2.0 for all three clusters is n=2.59+/-0.17 in the R band and 3.37+/-0.13 in the I band for a q0=1/2 model. The sensitivity of the result to the assumed value of q0 is shown to be less than 23% between q=0 and +1. The conclusion is that the exponent on (1+z) varies from 2.28 to 2.81(+/-0.17) in the R band and 3.06 to 3.55(+/-0.13) in the I band, depending on the value of q0. For a true Tolman signal with n=4, the luminosity evolution in the look-back time, expressed as the exponent in 2.5log(1+z)4-n mag, must then be between 1.72 to 1.19(+/-0.17) in the R band and 0.94 to 0.45(+/-0.13) in the I band. We show that this is precisely the range expected from the evolutionary models of Bruzual and Charlot and

  20. Neisseria meningitidis Differentially Controls Host Cell Motility through PilC1 and PilC2 Components of Type IV Pili

    PubMed Central

    Morand, Philippe C.; Drab, Marek; Rajalingam, Krishnaraj; Nassif, Xavier; Meyer, Thomas F.

    2009-01-01

    Neisseria meningitidis is a strictly human pathogen that has two facets since asymptomatic carriage can unpredictably turn into fulminant forms of infection. Meningococcal pathogenesis relies on the ability of the bacteria to break host epithelial or endothelial cellular barriers. Highly restrictive, yet poorly understood, mechanisms allow meningococcal adhesion to cells of only human origin. Adhesion of encapsulated and virulent meningococci to human cells relies on the expression of bacterial type four pili (T4P) that trigger intense host cell signalling. Among the components of the meningococcal T4P, the concomitantly expressed PilC1 and PilC2 proteins regulate pili exposure at the bacterial surface, and until now, PilC1 was believed to be specifically responsible for T4P-mediated meningococcal adhesion to human cells. Contrary to previous reports, we show that, like PilC1, the meningococcal PilC2 component is capable of mediating adhesion to human ME180 epithelial cells, with cortical plaque formation and F-actin condensation. However, PilC1 and PilC2 promote different effects on infected cells. Cellular tracking analysis revealed that PilC1-expressing meningococci caused a severe reduction in the motility of infected cells, which was not the case when cells were infected with PilC2-expressing strains. The amount of both total and phosphorylated forms of EGFR was dramatically reduced in cells upon PilC1-mediated infection. In contrast, PilC2-mediated infection did not notably affect the EGFR pathway, and these specificities were shared among unrelated meningococcal strains. These results suggest that meningococci have evolved a highly discriminative tool for differential adhesion in specific microenvironments where different cell types are present. Moreover, the fine-tuning of cellular control through the combined action of two concomitantly expressed, but distinctly regulated, T4P-associated variants of the same molecule (i.e. PilC1 and PilC2) brings a new

  1. The All-Alpha Domains of Coupling Proteins from the Agrobacterium tumefaciens VirB/VirD4 and Enterococcus faecalis pCF10-Encoded Type IV Secretion Systems Confer Specificity to Binding of Cognate DNA Substrates

    PubMed Central

    Whitaker, Neal; Chen, Yuqing; Jakubowski, Simon J.; Sarkar, Mayukh K.; Li, Feng

    2015-01-01

    ABSTRACT Bacterial type IV coupling proteins (T4CPs) bind and mediate the delivery of DNA substrates through associated type IV secretion systems (T4SSs). T4CPs consist of a transmembrane domain, a conserved nucleotide-binding domain (NBD), and a sequence-variable helical bundle called the all-alpha domain (AAD). In the T4CP structural prototype, plasmid R388-encoded TrwB, the NBD assembles as a homohexamer resembling RecA and DNA ring helicases, and the AAD, which sits at the channel entrance of the homohexamer, is structurally similar to N-terminal domain 1 of recombinase XerD. Here, we defined the contributions of AADs from the Agrobacterium tumefaciens VirD4 and Enterococcus faecalis PcfC T4CPs to DNA substrate binding. AAD deletions abolished DNA transfer, whereas production of the AAD in otherwise wild-type donor strains diminished the transfer of cognate but not heterologous substrates. Reciprocal swaps of AADs between PcfC and VirD4 abolished the transfer of cognate DNA substrates, although strikingly, the VirD4-AADPcfC chimera (VirD4 with the PcfC AAD) supported the transfer of a mobilizable plasmid. Purified AADs from both T4CPs bound DNA substrates without sequence preference but specifically bound cognate processing proteins required for cleavage at origin-of-transfer sequences. The soluble domains of VirD4 and PcfC lacking their AADs neither exerted negative dominance in vivo nor specifically bound cognate processing proteins in vitro. Our findings support a model in which the T4CP AADs contribute to DNA substrate selection through binding of associated processing proteins. Furthermore, MOBQ plasmids have evolved a docking mechanism that bypasses the AAD substrate discrimination checkpoint, which might account for their capacity to promiscuously transfer through many different T4SSs. IMPORTANCE For conjugative transfer of mobile DNA elements, members of the VirD4/TraG/TrwB receptor superfamily bind cognate DNA substrates through mechanisms that are

  2. SPIDER. IV. OPTICAL AND NEAR-INFRARED COLOR GRADIENTS IN EARLY-TYPE GALAXIES: NEW INSIGHT INTO CORRELATIONS WITH GALAXY PROPERTIES

    SciTech Connect

    La Barbera, F.; De Carvalho, R. R.; Gal, R. R.; Swindle, R.; Lopes, P. A. A.

    2010-11-15

    We present an analysis of stellar population gradients in 4546 early-type galaxies (ETGs) with photometry in grizYHJK along with optical spectroscopy. ETGs were selected as bulge-dominated systems, displaying passive spectra within the SDSS fibers. A new approach is described which utilizes color information to constrain age and metallicity gradients. Defining an effective color gradient, {nabla}{sub *}, which incorporates all of the available color indices, we investigate how {nabla}{sub *} varies with galaxy mass proxies, i.e., velocity dispersion, stellar (M{sub *}) and dynamical (M{sub dyn}) masses, as well as age, metallicity, and [{alpha}/Fe]. ETGs with M{sub dyn} larger than 8.5 x 10{sup 10} M{sub sun} have increasing age gradients and decreasing metallicity gradients with respect to mass, metallicity, and enhancement. We find that velocity dispersion and [{alpha}/Fe] are the main drivers of these correlations. ETGs with 2.5 x 10{sup 10} M{sub sun} {<=} M{sub dyn} {<=} 8.5 x 10{sup 10} M{sub sun} show no correlation of age, metallicity, and color gradients with respect to mass, although color gradients still correlate with stellar population parameters, and these correlations are independent of each other. In both mass regimes, the striking anti-correlation between color gradient and {alpha}-enhancement is significant at {approx}5{sigma} and results from the fact that metallicity gradient decreases with [{alpha}/Fe]. This anti-correlation may reflect the fact that star formation and metallicity enrichment are regulated by the interplay between the energy input from supernovae, and the temperature and pressure of the hot X-ray gas in ETGs. For all mass ranges, positive age gradients are associated with old galaxies (>5-7 Gyr). For galaxies younger than {approx}5 Gyr, mostly at low mass, the age gradient tends to be anti-correlated with the Age parameter, with more positive gradients at younger ages.

  3. A low-luminosity type-1 QSO sample . IV. Molecular gas contents and conditions of star formation in three nearby Seyfert galaxies

    NASA Astrophysics Data System (ADS)

    Moser, Lydia; Krips, Melanie; Busch, Gerold; Scharwächter, Julia; König, Sabine; Eckart, Andreas; Smajić, Semir; García-Marin, Macarena; Valencia-S., Mónica; Fischer, Sebastian; Dierkes, Jens

    2016-03-01

    We present a pilot study of ~3'' resolution observations of low CO transitions with the Submillimeter Array in three nearby Seyfert galaxies, which are part of the low-luminosity quasi-stellar object (LLQSOs) sample consisting of 99 nearby (z = 0.06) type-1 active galactic nuclei (AGN) taken from the Hamburg/ESO quasi-stellar object (QSO) survey. Two sources were observed in 12CO(2-1) and 13CO(2-1) and the third in 12CO(3-2) and HCO+(4-3). None of the sources is detected in continuum emission. More than 80% of the 12CO detected molecular gas is concentrated within a diameter (FWHM) < 1.8 kpc. 13CO is tentatively detected, while HCO+ emission could not be detected. All three objects show indications of a kinematically decoupled central unresolved molecular gas component. The molecular gas masses of the three galaxies are in the range Mmol = (0.7-8.7) × 109M⊙. We give lower limits for the dynamical masses of Mdyn> 1.5 × 109M⊙ and for the dust masses of Mdust> 1.6 × 106M⊙. The R21 = 12CO/13CO(2-1) line luminosity ratios show Galactic values of R21 ~ 5-7 in the outskirts and R21 ≳ 20 in the central region, similar to starbursts and (ultra)luminous infrared galaxies ((U)LIRGs; i.e. LIRGs and ULIRGs), implying higher temperatures and stronger turbulence. All three sources show indications of 12CO(2-1)/12CO(1-0) ratios of ~0.5, suggesting a cold or diffuse gas phase. Strikingly, the 12CO(3-2)/(1-0) ratio of ~1 also indicates a higher excited phase. Since these galaxies have high infrared luminosities of LIR ≥ 1011L⊙ and seem to contain a circumnuclear starburst with minimum surface densities of gas and star formation rate (SFR) around Σmol = 50-550 M⊙pc-2 and ΣSFR = 1.1-3.1 M⊙ kpc-2 yr-1, we conclude that the interstellar medium in the centers of these LIRG Seyferts is strongly affected by violent star formation and better described by the ULIRG mass conversion factor.

  4. PLATO IV Accountancy Index.

    ERIC Educational Resources Information Center

    Pondy, Dorothy, Comp.

    The catalog was compiled to assist instructors in planning community college and university curricula using the 48 computer-assisted accountancy lessons available on PLATO IV (Programmed Logic for Automatic Teaching Operation) for first semester accounting courses. It contains information on lesson access, lists of acceptable abbreviations for…

  5. IVS Technology Coordinator Report

    NASA Technical Reports Server (NTRS)

    Whitney, Alan

    2013-01-01

    This report of the Technology Coordinator includes the following: 1) continued work to implement the new VLBI2010 system, 2) the 1st International VLBI Technology Workshop, 3) a VLBI Digital- Backend Intercomparison Workshop, 4) DiFX software correlator development for geodetic VLBI, 5) a review of progress towards global VLBI standards, and 6) a welcome to new IVS Technology Coordinator Bill Petrachenko.

  6. The PLATO IV Architecture.

    ERIC Educational Resources Information Center

    Stifle, Jack

    The PLATO IV computer-based instructional system consists of a large scale centrally located CDC 6400 computer and a large number of remote student terminals. This is a brief and general description of the proposed input/output hardware necessary to interface the student terminals with the computer's central processing unit (CPU) using available…

  7. Little Jiffy, Mark IV

    ERIC Educational Resources Information Center

    Kaiser, Henry F.; Rice, John

    1974-01-01

    In this paper three changes and one new development for the method of exploratory factor analysis (a second generation Little Jiffy) developed by Kaiser are described. Following this short description a step-by-step computer algorithm of the revised method, dubbed Little Jiffy, Mark IV is presented. (MP)

  8. (2R)-4-Oxo-4[3-(Trifluoromethyl)-5,6-diihydro:1,2,4}triazolo[4,3-a}pyrazin-7(8H)-y1]-1-(2,4,5-trifluorophenyl)butan-2-amine: A Potent, Orally Active Dipeptidyl Peptidase IV Inhibitor for the Treatment of Type 2 Diabetes

    SciTech Connect

    Kim, D.; Wang, L.; Beconi, M.; Eiermann, G.; Fisher, M.; He, H.; Hickey, G.; Kowalchick, Jennifer; Leiting, Barbara; Lyons, K.; Marsilio, F.; McCann, F.; Patel, R.; Petrov, A.; Scapin, G.; Patel, S.; Roy, R.; Wu, J.; Wyvratt, M.; Zhang, B.; Zhu, L.; Thornberry, N.; Weber, A.

    2010-11-10

    A novel series of {beta}-amino amides incorporating fused heterocycles, i.e., triazolopiperazines, were synthesized and evaluated as inhibitors of dipeptidyl peptidase IV (DPP-IV) for the treatment of type 2 diabetes. (2R)-4-Oxo-4-[3-(trifluoromethyl)-5,6-dihydro[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl]-1-(2,4,5-trifluorophenyl)butan-2-amine (1) is a potent, orally active DPP-IV inhibitor (IC{sub 50} = 18 nM) with excellent selectivity over other proline-selective peptidases, oral bioavailability in preclinical species, and in vivo efficacy in animal models. MK-0431, the phosphate salt of compound 1, was selected for development as a potential new treatment for type 2 diabetes.

  9. Genetics Home Reference: mucolipidosis type IV

    MedlinePlus

    ... mucolipin-1 plays a role in the transport (trafficking) of fats (lipids) and proteins between lysosomes and ... Accessibility FOIA Viewers & Players U.S. Department of Health & Human Services National Institutes of Health National Library of ...

  10. Congenital Insensitivity to Pain (HSNA type IV).

    PubMed

    Millichap, J Gordon

    2015-04-01

    Investigators from New York University, NY, studied 14 patients with congenital insensitivity to pain with anhidrosis (CIPA), compared to 10 patients with chronically deficient sympathetic activity (pure autonomic failure), and 15 normal age-matched controls.

  11. Antibodies against the majority subunit of Type IV pili disperse nontypeable Haemophilus influenzae biofilms in a LuxS-dependent manner and confer therapeutic resolution of experimental otitis media

    PubMed Central

    Novotny, Laura A.; Jurcisek, Joseph A.; Ward, Michael O.; Jordan, Zachary B.; Goodman, Steven D.; Bakaletz, Lauren O.

    2015-01-01

    Summary Despite resulting in a similar overall outcome, unlike antibodies directed against the DNABII protein, integration host factor (IHF), which induce catastrophic structural collapse of biofilms formed by nontypeable Haemophilus influenzae (NTHI), those directed against a recombinant soluble form of PilA [the majority subunit of Type IV pili (Tfp) produced by NTHI], mediated gradual ‘top-down’ dispersal of NTHI from biofilms. This dispersal occurred via a mechanism that was dependent upon expression of both PilA (and by inference, Tfp) and production of AI-2 quorum signaling molecules by LuxS. The addition of rsPilA to a biofilm-targeted therapeutic vaccine formulation comprised of IHF plus the powerful adjuvant dmLT, and delivered via a non-invasive transcutaneous immunization route, induced an immune response that targeted two important determinants essential for biofilm formation by NTHI. This resulted in significantly earlier eradication of NTHI from both planktonic and adherent populations in the middle ear, disruption of mucosal biofilms already resident within middle ears prior to immunization, and rapid resolution of signs of disease in an animal model of experimental otitis media. These data support continued development of this novel combinatorial immunization approach for resolution and/or prevention of multiple diseases of the respiratory tract caused by NTHI. PMID:25597921

  12. Antibodies against the majority subunit of type IV Pili disperse nontypeable Haemophilus influenzae biofilms in a LuxS-dependent manner and confer therapeutic resolution of experimental otitis media.

    PubMed

    Novotny, Laura A; Jurcisek, Joseph A; Ward, Michael O; Jordan, Zachary B; Goodman, Steven D; Bakaletz, Lauren O

    2015-04-01

    Despite resulting in a similar overall outcome, unlike antibodies directed against the DNABII protein, integration host factor (IHF), which induce catastrophic structural collapse of biofilms formed by nontypeable Haemophilus influenzae (NTHI), those directed against a recombinant soluble form of PilA [the majority subunit of Type IV pili (Tfp) produced by NTHI], mediated gradual 'top-down' dispersal of NTHI from biofilms. This dispersal occurred via a mechanism that was dependent upon expression of both PilA (and by inference, Tfp) and production of AI-2 quorum signaling molecules by LuxS. The addition of rsPilA to a biofilm-targeted therapeutic vaccine formulation comprised of IHF plus the powerful adjuvant dmLT and delivered via a noninvasive transcutaneous immunization route induced an immune response that targeted two important determinants essential for biofilm formation by NTHI. This resulted in significantly earlier eradication of NTHI from both planktonic and adherent populations in the middle ear, disruption of mucosal biofilms already resident within middle ears prior to immunization and rapid resolution of signs of disease in an animal model of experimental otitis media. These data support continued development of this novel combinatorial immunization approach for resolution and/or prevention of multiple diseases of the respiratory tract caused by NTHI.

  13. Optimal and safe treatment of spider leg veins measuring less than 1.5 mm on skin type IV patients, using repeated low-fluence Nd:YAG laser pulses after polidocanol injection.

    PubMed

    Moreno-Moraga, Javier; Hernández, Esteban; Royo, Josefina; Alcolea, Justo; Isarría, M Jose; Pascu, Mihail Lucian; Smarandache, Adriana; Trelles, Mario

    2013-05-01

    Treatment of micro-veins of less than 1.5 mm with laser and with chemical sclerosis is technically challenging because of their difficulty to remedy. Laser treatment is even more difficult when dark phototypes are involved.Three groups of 30 patients each, skin type IV, and vessels measuring less than 1.5 mm in diameter, were enrolled for two treatment sessions 8 weeks apart: group A, polidocanol (POL) micro-foam injection; group B, Nd:YAG laser alone; and group C, laser after POL injection. Repeated 8-Hz low-fluence pulses, moving the hand piece over a 3-cm vein segment with an average of five laser passes maximum and with a total time irradiation of 1 s were used. Sixteen weeks after the second treatment, statistically, degree of clearance after examining photographs and patients satisfaction index, plotted on a visual analogue scale and comparing results of all three groups, results were significantly better for group C (p<0.0001). No significant differences in complications were noticed between the three groups. Efficacy of combining POL and laser proved safe and satisfactory in 96 % of patients using low-fluence laser pulses with a total cumulative energy in the 3 cm venous segment, lower than that of conventional treatment. Very few and transient complications were observed. POL foam injection followed by laser pulses is safe and efficient for vein treatment in dark-skinned patients.