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Isolation from a Healthy Carrier and Characterization of a Neisseria meningitidis Strain That Is Deficient in γ-Glutamyl Aminopeptidase Activity

Takahashi, Hideyuki; Tanaka, Hiroshi; Inouye, Hiroo; Kuroki, Toshiro; Watanabe, Yuko; Yamai, Shiro; Watanabe, Haruo
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: text
Publicado em /08/2002 Português
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γ-Glutamyl aminopeptidase (GGT) activity is used as a specific marker for the identification of Neisseria meningitidis. We isolated from a healthy carrier and characterized an N. meningitidis isolate which lacked the activity due to the insertional mutation of the ggt gene, suggesting that naturally occurring N. meningitidis isolates do not always possess GGT activity.

In vitro activity of carumonam.

Fass, R J; Helsel, V L
Tipo: text
Publicado em /12/1985 Português
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The in vitro activities of carumonam and eight comparative antimicrobial agents were studied. MICs of carumonam were less than or equal to 0.5 microgram/ml for 91% of members of the family Enterobacteriaceae and less than or equal to 16 micrograms/ml for 88% of nonfermenters; gram-positive cocci and anaerobic bacteria were resistant. Combinations of carumonam with piperacillin, nafcillin, or clindamycin were usually indifferent, although synergy between carumonam and piperacillin was observed with 20 (13%) of 155 strains.

Enumeration of enterotoxigenic Bacteroides fragilis in municipal sewage.

Shoop, D S; Myers, L L; LeFever, J B
Tipo: text
Publicado em /07/1990 Português
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Of 237 isolates of Bacteroides fragilis from sewage influent at the Bozeman, Mont., wastewater treatment plant, 22 (9.3%) were enterotoxigenic, as indicated by the ability to elicit fluid accumulation in the lamb ileal loop test. It appears that enterotoxigenic B. fragilis is endemic in the human population at a moderately high level.

150 Practice ECGs: Interpretation and Board Review

Hall, Robert J.
Tipo: text
Publicado em //1997 Português
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Persistent Infection of BSC-1 Cells by Defective Measles Virus Derived From Subacute Sclerosing Panencephalitis

Burnstein, Theodore; Jacobsen, Linda B.; Zeman, Wolfgang; Chen, Tsu T.
Tipo: text
Publicado em /12/1974 Português
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A line of cells (IP-3), persistently infected with defective measles virus, was developed from co-cultures of subacute sclerosing panencephalitis-derived brain cells with monkey kidney cells (BSC-1). The line, carried for more than 45 serial passages, produced neither infectious virus nor hemagglutinin. Cultures consistently displayed a cycling focal cytopathic pattern of infection characterized by formation of syncytia, necrosis, and plaques followed by healing. Fluorescent measles antigen was present in damaged areas only, especially in syncytia. The development of syncytia was suppressed by measles antibody. Syncytia were lysed by antibody plus rabbit complement. A variant noncytopathic subline (IP-3-Ca) was derived from the 16th passage. Infectious virus was not detected. Cells were minimally positive for hemadsorption. Fluorescent measles antigen was present in all cells. Co-cultures of IP-3-Ca cells with normal BSC-1 cells developed massive syncytia and extensive destruction. The IP-3-Ca cells multiplied in the presence of measles antibodies and were destroyed by antibodies plus complement. The possible relevance of these findings to the pathogenesis of subacute sclerosing panencephalitis is discussed.

Blockage of axonal transport induced by acute, graded compression of the rabbit vagus nerve.

Rydevik, B; McLean, W G; Sjöstrand, J; Lundborg, G
Tipo: text
Publicado em /08/1980 Português
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Rapid axonal transport in rabbit vagus nerve was studied during and after graded nerve compression. Proteins of the rapid axonal transport were labelled by micro-injection of 3H-leucine into the nodose ganglion and the cervical vagus nerve was subjected to graded compression by a small "mini-cuff" applied directly to the exposed nerve trunk. The results showed that even slight trauma to the nerve, in this model represented by a pressure at 50 mmHg applied for two hours, may induce accumulation of axonally transported proteins at the level of compression. This transport block was, however, reversible within one day. 200 mmHg and 400 mmHg applied for two hours similarly induced a block of axonal transport persisting up to at least one and three days respectively after the compression. Time for recovery of normal transport was correlated with the magnitude of the pressure applied to the nerve. The results indicate that axons may survive, that is not undergo Wallerian degeneration, after blockage of rapid axonal transport persisting at least one day after the compression trauma.

Military approach to medical planning in humanitarian operations

Bricknell, Martin C M; MacCormack, Tracey
Fonte: BMJ Publishing Group Ltd. Publicador: BMJ Publishing Group Ltd.
Tipo: text
Publicado em 18/06/2005 Português
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Ultrafine Particles Cross Cellular Membranes by Nonphagocytic Mechanisms in Lungs and in Cultured Cells

Geiser, Marianne; Rothen-Rutishauser, Barbara; Kapp, Nadine; Schürch, Samuel; Kreyling, Wolfgang; Schulz, Holger; Semmler, Manuela; Hof, Vinzenz Im; Heyder, Joachim; Gehr, Peter
Fonte: National Institute of Environmental Health Sciences Publicador: National Institute of Environmental Health Sciences
Tipo: text
Português
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High concentrations of airborne particles have been associated with increased pulmonary and cardiovascular mortality, with indications of a specific toxicologic role for ultrafine particles (UFPs; particles < 0.1 μm). Within hours after the respiratory system is exposed to UFPs, the UFPs may appear in many compartments of the body, including the liver, heart, and nervous system. To date, the mechanisms by which UFPs penetrate boundary membranes and the distribution of UFPs within tissue compartments of their primary and secondary target organs are largely unknown. We combined different experimental approaches to study the distribution of UFPs in lungs and their uptake by cells. In the in vivo experiments, rats inhaled an ultrafine titanium dioxide aerosol of 22 nm count median diameter. The intrapulmonary distribution of particles was analyzed 1 hr or 24 hr after the end of exposure, using energy-filtering transmission electron microscopy for elemental microanalysis of individual particles. In an in vitro study, we exposed pulmonary macrophages and red blood cells to fluorescent polystyrene microspheres (1, 0.2, and 0.078 μm) and assessed particle uptake by confocal laser scanning microscopy. Inhaled ultrafine titanium dioxide particles were found on the luminal side of airways and alveoli...

Response in the Yield of Milk Constituents to the Intake of Nutrients by Dairy Cows

Duffield, Todd
Tipo: text
Publicado em /03/2000 Português
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ABSTRACTS FROM CURRENT LITERATURE

Tipo: text
Publicado em /08/1926 Português
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Careers for diabetic girls in nursing

Browning, H K E
Tipo: text
Publicado em 26/07/1980 Português
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Foreign Bodies in the Rectum

Hazzard, T. L.
Tipo: text
Publicado em /10/1911 Português
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Functional analysis of genes involved in the biosynthesis of isoprene in Bacillus subtilis

Julsing, Mattijs K.; Rijpkema, Michael; Woerdenbag, Herman J.; Quax, Wim J.; Kayser, Oliver
Fonte: Springer-Verlag Publicador: Springer-Verlag
Tipo: text
Português
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In comparison to other bacteria Bacillus subtilis emits the volatile compound isoprene in high concentrations. Isoprene is the smallest representative of the natural product group of terpenoids. A search in the genome of B. subtilis resulted in a set of genes with yet unknown function, but putatively involved in the methylerythritol phosphate (MEP) pathway to isoprene. Further identification of these genes would give the possibility to engineer B. subtilis as a host cell for the production of terpenoids like the valuable plant-produced drugs artemisinin and paclitaxel. Conditional knock-out strains of putative genes were analyzed for the amount of isoprene emitted. Differences in isoprene emission were used to identify the function of the enzymes and of the corresponding selected genes in the MEP pathway. We give proof on a biochemical level that several of these selected genes from this species are involved in isoprene biosynthesis. This opens the possibilities to investigate the physiological function of isoprene emission and to increase the endogenous flux to the terpenoid precursors, isopentenyl diphosphate and dimethylallyl diphosphate, for the heterologous production of more complex terpenoids in B. subtilis.

Effects of Cholesterol on Dry Bilayers: Interactions between Phosphatidylcholine Unsaturation and Glycolipid or Free Sugar

Popova, Antoaneta V.; Hincha, Dirk K.
Fonte: The Biophysical Society Publicador: The Biophysical Society
Tipo: text
Português
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Cholesterol and other sterols are important components of biological membranes and are known to strongly influence the physical characteristics of lipid bilayers. Although this has been studied extensively in fully hydrated membranes, little is known about the effects of cholesterol on the stability of membranes in the dry state. Here, we present a Fourier transform infrared spectroscopy study on the effects of cholesterol on the phase behavior of dry liposomes composed of phosphatidylcholines with different degrees of fatty acid unsaturation or of mixtures of phosphatidylcholine with a plant galactolipid. In addition, we have analyzed the H-bonding of cholesterol, galactose, and a combination of the two additives to the P=O and C=O groups in dry phosphatidylcholine bilayers. The data indicate a complex balance of interactions between the different components in the dry state and a strong influence of fatty acid unsaturation on the interactions of the diacyl lipids with both cholesterol and galactose.

Solvation Effect of Bacteriochlorophyll Excitons in Light-Harvesting Complex LH2

Urbonienė, V.; Vrublevskaja, O.; Trinkunas, G.; Gall, A.; Robert, B.; Valkunas, L.
Fonte: Biophysical Society Publicador: Biophysical Society
Tipo: text
Português
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We have characterized the influence of the protein environment on the spectral properties of the bacteriochlorophyll (Bchl) molecules of the peripheral light-harvesting (or LH2) complex from Rhodobacter sphaeroides. The spectral density functions of the pigments responsible for the 800 and 850 nm electronic transitions were determined from the temperature dependence of the Bchl absorption spectra in different environments (detergent micelles and native membranes). The spectral density function is virtually independent of the hydrophobic support that the protein experiences. The reorganization energy for the B850 Bchls is 220 cm−1, which is almost twice that of the B800 Bchls, and its Huang-Rhys factor reaches 8.4. Around the transition point temperature, and at higher temperatures, both the static spectral inhomogeneity and the resonance interactions become temperature-dependent. The inhomogeneous distribution function of the transitions exhibits less temperature dependence when LH2 is embedded in membranes, suggesting that the lipid phase protects the protein. However, the temperature dependence of the fluorescence spectra of LH2 cannot be fitted using the same parameters determined from the analysis of the absorption spectra. Correct fitting requires the lowest exciton states to be additionally shifted to the red...

Serological tests for the detection of antibodies to Mycoplasma gallisepticum in chickens and turkeys.

Jordan, F. T.; Kulasegaram, P.
Fonte: Cambridge University Press Publicador: Cambridge University Press
Tipo: text
Publicado em /06/1968 Português
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US needs universal access to health care, American College of Physicians says

Tanne, Janice Hopkins
Fonte: BMJ Publishing Group Ltd. Publicador: BMJ Publishing Group Ltd.
Tipo: text
Publicado em 15/12/2007 Português
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Intracranial calcification with IgG λ M-proteinaemia: a case report

ISOE, K.; URAKAMI, K.; SHOJI, M.; NAKASHIMA, K.
Fonte: BMJ Group Publicador: BMJ Group
Tipo: text
Publicado em /04/1998 Português
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The Atypical Rho GTPase Wrch1 Collaborates with the Nonreceptor Tyrosine Kinases Pyk2 and Src in Regulating Cytoskeletal Dynamics▿

Ruusala, Aino; Aspenström, Pontus
Fonte: American Society for Microbiology (ASM) Publicador: American Society for Microbiology (ASM)
Tipo: text
Português
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The Cdc42-like GTPase Wnt responsive Cdc42 homolog 1 (Wrch1) has several atypical features; it has an N-terminal proline-rich extension that confers binding to SH3 domains, and it harbors an extremely high intrinsic nucleotide exchange activity, which overrides the normal GTPase activity. As a result, Wrch1 resides mainly in the active, GTP-loaded conformation under normal cellular conditions. We have previously shown that ectopic expression of Wrch1 in fibroblasts resulted in an altered cell morphology visible as a formation of filopodia, a loss of stress fibers, and a reduction in focal adhesions. Here, we show that Wrch1 binds to the nonreceptor tyrosine kinase Pyk2. The interaction required Wrch1 to be in a GTP conformation and also required an intact N-terminal proline-rich extension as well as an intact effector loop. Wrch1 requires Pyk2 in imposing the cytoskeletal effects, seen as the formation of filopodia, since treatment of cells with a Pyk2-specific small interfering RNA abrogated this response. Interestingly, we found that the presence and activity of Src were needed for the formation of a Wrch1-Pyk2 complex as well as for the Wrch1-induced formation of filopodia. We propose a model in which Pyk2 and Src function to coordinate the Wrch1-dependent effects on cytoskeletal dynamics.

REFRESHER COURSES FOR SHIP SURGEONS

Birch, C. Allan
Tipo: text
Publicado em 22/08/1931 Português
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