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61.
B Abt C Han C Scheuner M Lu A Lapidus M Nolan S Lucas N Hammon S Deshpande JF Cheng R Tapia LA Goodwin S Pitluck K Liolios I Pagani N Ivanova K Mavromatis N Mikhailova M Huntemann A Pati A Chen K Palaniappan M Land L Hauser EM Brambilla M Rohde S Spring S Gronow M Göker T Woyke J Bristow JA Eisen V Markowitz P Hugenholtz NC Kyrpides HP Klenk JC Detter 《Standards in genomic sciences》2012,6(2):194-209
Spirochaeta coccoides Dröge et al. 2006 is a member of the genus Spirochaeta Ehrenberg 1835, one of the oldest named genera within the Bacteria. S. coccoides is an obligately anaerobic, Gram-negative, non-motile, spherical bacterium that was isolated from the hindgut contents of the termite Neotermes castaneus. The species is of interest because it may play an important role in the digestion of breakdown products from cellulose and hemicellulose in the termite gut. Here we provide a taxonomic re-evaluation for strain SPN1T, and based on physiological and genomic characteristics, we propose its reclassification as a novel species in the genus Sphaerochaeta, a recently published sister group of the Spirochaeta. The 2,227,296 bp long genome of strain SPN1T with its 1,866 protein-coding and 58 RNA genes is a part of the Genomic
Encyclopedia of
Bacteria and
Archaea project. 相似文献
62.
Applications of small molecule activators and inhibitors of quorum sensing in Gram-negative bacteria
Quorum sensing is a form of intercellular communication used by many species of bacteria that facilitates concerted interactions between the cells comprising a population. The phenotypes regulated by quorum sensing are extremely diverse, with many having a significant impact upon healthcare, agriculture, and the environment. Consequently there has been significant interest in developing methods to manipulate this signalling process and recent years have witnessed significant theoretical and practical developments. A wide range of small molecule modulators of quorum sensing systems has been discovered, providing an expansive chemical toolbox for the study and modulation of this signalling mechanism. In this review, a selection of recent case studies which illustrate the value of both activators and inhibitors of quorum sensing in Gram-negative bacteria are discussed. 相似文献
63.
An optimized procedure for the efficient preparation of 2-heptyl-3-hydroxy-4(1H)-quinolone (Pseudomonas quinolone signal or PQS) and a diverse range of structurally related 2-alkyl-4-quinolones with biological activity is presented. The two-step synthesis begins with the formation of α-chloro ketones by the coupling of a Weinreb amide (2-chloro-N-methoxy-N-methylacetamide) and an appropriate Grignard reagent. The resulting α-chloro ketones can be reacted with commercially available anthranilic acids under microwave irradiation conditions to furnish the desired 2-alkyl-4-quinolone products. As a typical example, the synthesis of PQS, a molecule involved in quorum sensing in the pathogenic bacterium Pseudomonas aeruginosa, is described in detail. The first step of this process (α-chloro ketone formation) takes ~10 h in total to complete from commercially available bromoheptane and 2-chloro-N-methoxy-N-methylacetamide. The second step (microwave-assisted reaction with anthranilic acid) takes ~14 h in total to complete (the reaction typically proceeds in ~30 min, with work-up and purification requiring ~13 h). 相似文献
64.
Pauly C Spring P O'Doherty JV Ampuero Kragten S Bee G 《Animal : an international journal of animal bioscience》2008,2(11):1707-1715
In Europe there is increasing concern about the common practice of surgical castration of piglets without anaesthesia. One possible alternative to completely avoid castration is entire male pig production. Thus, the objective of the study was to compare the growth performance, carcass characteristics, organ weights, meat quality traits, fat score and boar taint compounds in the adipose tissue of group-penned entire male pigs and castrates. Furthermore, the effect of raw potato starch (RPS) fed for 7 days prior to slaughter was determined. Pigs (n = 36) were blocked by BW into 12 blocks (3 littermates/block) and assigned to three experimental groups: surgical castrates (C); entire males (EM); and entire males offered RPS (30 g RPS/100 g diet) for 7 days prior to slaughter (EM+). Pigs had ad libitum access to the feed from 22 to 107 kg, individual feed intake was recorded daily and BW once a week. Entire males grew slower (EM: 771, EM+: 776 v. C: 830 g/day; P < 0.01), consumed less feed (EM: 1.87, EM+: 1.89 v. C: 2.23 kg/day; P < 0.01) and were more efficient (feed conversion ratio: EM: 2.42, EM+: 2.44 v. C: 2.69 kg/kg; P < 0.01) than C. Compared to C, carcass dressing percentage was lower (EM: 79.4, EM+: 79.4 v. C: 81.6%; P < 0.01) and percentage of valuable cuts was higher (EM: 57.3, EM+: 56.5 v. 52.6%; P < 0.01) in entire males. The hearts (EM: 426, EM+: 425 v. C: 378 g), kidneys (EM: 387, EM+: 378 v. C: 311 g), bulbourethral (EM: 200, EM+: 195 v. C: 7 g) and salivary glands (EM: 99, EM+: 94 v. C: 42 g) were heavier (P < 0.001) in entire males than in C. Meat quality traits did not (P > 0.05) differ among experimental groups but the adipose tissue was more unsaturated in entire males than in C as indicated by the higher fat scores (EM: 69.1, EM+: 67.2 v. C: 63.6; P < 0.01). Feeding RPS reduced (P = 0.04) the skatole tissue concentrations (expressed in μg/g lipid) in EM+ (0.22) compared to EM (0.85), whereas androstenone and indole levels were not (P 0.60) affected (EM: 1.7 and 0.10, EM+: 2.0 and 0.09, respectively). Although the current results confirmed the high efficiency of entire males compared to castrates, the observed high androstenone levels represent a major challenge to implement entire males production. 相似文献
65.
Bending the MDCK Cell Primary Cilium Increases Intracellular Calcium 总被引:29,自引:0,他引:29
We tested the hypothesis that the primary cilium of renal epithelia is mechanically sensitive and serves as a flow sensor
in MDCK cells using differential interference contrast and fluorescence microscopy. Bending the cilium, either by suction
with a micropipette or by increasing the flow rate of perfusate, causes intracellular calcium to substantially increase as
indicated by the fluorescent indicator, Fluo-4. This calcium signal is initiated by Ca2+-influx through mechanically sensitive channels that probably reside in the cilium or its base. The influx is followed by
calcium release from IP3-sensitive stores. The calcium signal then spreads as a wave from the perturbed cell to its neighbors by diffusion of a second
messenger through gap junctions. This spreading of the calcium wave points to flow sensing as a coordinated event within the
tissue, rather than an isolated phenomenon in a single cell. Measurement of the membrane potential difference by microelectrode
during perfusate flow reveals a profound hyperpolarization during the period of elevated intracellular calcium. We conclude
that the primary cilium in MDCK cells is mechanically sensitive and responds to flow by greatly increasing intracellular calcium.
Received: 4 April 2001/Revised: 28 June 2001 相似文献
66.
Current-induced voltage transients in Necturus proximal tubule 总被引:3,自引:0,他引:3
K R Spring 《The Journal of membrane biology》1973,13(4):299-322
67.
68.
69.
Igor Elman Tamara V. Gurvits Evelyne Tschibelu Justin D. Spring Natasha B. Lasko Roger K. Pitman 《PloS one》2013,8(4)
Increased neurological soft signs (NSSs) have been found in a number of neuropsychiatric syndromes, including chemical addiction. The present study examined NSSs related to perceptual-motor and visuospatial processing in a behavioral addiction viz., pathological gambling (PG). As compared to mentally healthy individuals, pathological gamblers displayed significantly poorer ability to copy two- and three-dimensional figures, to recognize objects against a background noise, and to orient in space on a road-map test. Results indicated that PG is associated with subtle cerebral cortical abnormalities. Further prospective clinical research is needed to address the NSSs'' origin and chronology (e.g., predate or follow the development of PG) as well as their response to therapeutic interventions and/or their ability to predict such a response. 相似文献
70.
The lateral intercellular spaces (LIS) of MDCK cell epithelia grown on permeable supports are about 0.4 pH units acidic to
the bathing solutions, presumably because of buffering by the fixed negative charges on the surface of the lateral cell membranes.
To test the hypothesis that fixed buffers are responsible for the acidity, a theoretical and experimental approach was developed
for the determination of the concentration and pK of the fixed buffer constituted by the glycocalyx. The pH of the solution
in the LIS was measured by ratiometric fluorescence microscopy while the buffer concentration or composition of the bathing
solutions was altered. In addition, the divalent cation Sr2+ was added to the perfusion solutions to displace protons from the fixed buffer sites for the determination of the fixed buffer
properties. We conclude that the LIS contain 3.7 mm of pK 6.2 fixed buffer and that this buffer is responsible for the acidic microenvironment in the LIS.
Received: 9 April 1998/Revised: 28 July 1998 相似文献