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Query: UNIPROT:Q9UIJ5 (
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)
58,342
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Sublethal concentrations of
formic acid
(10 mmol/l) and propionic acid (5 mmol/l) at pH 5.0 preferentially inhibit DNA synthesis and stop cell multiplication in the absence of a corresponding cessation in the increase of culture turbidity. The possibility that the acids induce the SOS response by starving cells of thymine or by causing physical damage to the DNA molecule has now been investigated. Accumulation of thymine into the cytoplasm of whole cells was not inhibited by either acid. Mutants defective in excision repair (uvr A6), recombination repair (
rec
A56) and polymerase activity (pol A1) were not more sensitive to the acids than their isogenic parent. No significant increase in cell length was observed from measurements of transmission electron microscope images of acid-treated cells. It is concluded, therefore, that sublethal concentrations of formic and propionic acid inhibit DNA synthesis without physically damaging DNA molecule, or starving the cell of essential thymine or otherwise inducing an SOS response.
...
PMID:Inhibition of Escherichia coli K12 by short-chain organic acids: lack of evidence for induction of the SOS response. 201 50
Although the artery wall consists of three distinct layers, only the structures of the intima and media have been well characterized. The adventitia has generally been overlooked. Our examination focused on the organization of elastin and collagen which are the major components of this tunic. Canine infrarenal aortas were excised, stretched to their in vivo length, then pressure fixed in formalin. Transverse, longitudinal, and frontal sections were prepared with specific elastin and collagen stains. Areas of adventitia in these sections were examined with LM, and interconnections between collagen and elastin were photographed at various magnifications. Subsequently, the slides were fractured for attachment to SEM stubs, and the coverslips were demounted. The identical areas were then examined with SEM using the LM micrographs as a guide to identify elastin and collagen. Whole mount aortic ring preparations were digested in
formic acid
for 72 and 96 h at 45 degrees C to confirm adventitial elastin architecture. The adventitia was organized in alternating lamellae of collagen and elastin. The elastin lamellae consisted of continuous sheets of elastin with a longitudinal fibrillar substructure. Finer circumferential elastin fibers were also identified. These attached to both longitudinal elastin and adjacent collagen lamellae. Collagen lamellae were arranged in broad corrugated bands of fibrils. The unique architecture of the adventitia may explain some of the visco-elastic properties of the aorta in both normal and pathologic states.
Anat
Rec
1991 May
PMID:The architecture of adventitial elastin in the canine infrarenal aorta. 206 31
In three experiments a solution of
formic acid
(Bioadd) was added to feed 'naturally' contaminated with salmonellas. In two of them no salmonella infections were demonstrated in broiler chickens given feed containing 0.6 per cent (w/w) of the
formic acid
solution for seven weeks and in the third the infection rate was reduced considerably. In four other experiments the feed was contaminated artificially with between 1 and 47 Salmonella kedougou/g and a second product (BPO12), consisting of a mixture of
formic acid
and propionic acid, was evaluated. When it was added at 0.5 to 0.68 per cent (w/w) only one of 30 groups of 10 to 12 birds became infected with S kedougou by two weeks of age, compared with 22 of 27 control groups. The treatment of the feed with BPO12 one week before the addition of the salmonellas prevented the establishment of infection in chicks given the treated feed, indicating that acid treatment will provide protection against subsequent recontamination of the feed with the organisms. The isolation rate of S kedougou from artificially contaminated feed treated with BPO12 was reduced only slightly but the feed was apparently 'safe' for the birds which consumed it.
Vet
Rec
1988 Oct 15
PMID:Control of salmonella infections in broiler chickens by the acid treatment of their feed. 320 69
A combination of intravascular resin injection and
formic acid
incubation was utilized to study the three-dimensional arrangement of the elastic fibers in the loose connective tissue (superficial fascia) of the rat limb by scanning electron microscopy (SEM). The cast of the microvasculature served as a scaffolding for the otherwise collapsible connective tissue. SEM study demonstrated that the elastic fibers did not form an anastomosing network but were arranged in multiple layers. The fibers in each layer lay parallel to each other but were oriented differently from the fibers in the layers on either side, thereby producing a meshwork. Each individual fiber was composed of a small bundle of discrete fibrils. Some of these component fibrils separated from the parent fiber and united with other fibers, thus producing branching. The elastic fiber either decreased or grew in size by the respective sharing or joining of these component fibrils with neighboring fibers in their respective layers. Interconnections between elastic fibers of different layers were rare. These findings may provide a morphological explanation for the characteristic function of the superficial fascia, which allows the skin and underlying muscles to have a rapid and extensive alteration in their relative positions.
Anat
Rec
1988 Oct
PMID:Scanning electron microscope study of elastic fibers of the loose connective tissue (superficial fascia) in the rat. 321 61
Cheviot sheep from the Neuropathogenesis Unit flock were examined for PrP in brain sections using immunocytochemistry in order to aid scrapie diagnosis. Brains were collected from sheep which had been naturally or experimentally infected with scrapie and fixed in periodate-lysine-paraformaldehyde or in formalin. Immunolabelling was achieved using a monoclonal antibody (FH11) raised to the N-terminus of recombinant PrP protein. Several pre-treatments were studied in an effort to enhance PrP immunolabelling such as trypsin,
formic acid
and hydrated autoclaving. Trypsin was successful in highlighting PrP staining in formalin-fixed tissue. PrP staining was regularly observed in the dorsal vagus nucleus of the medulla oblongata and in the thalamus. Differences in the distribution and intensity of PrP immunostaining were apparent between the scrapie sources ME7 and SSBP/I.
Vet
Rec
1996 Nov 23
PMID:Immunolocalisation of the prion protein (PrP) in the brains of sheep with scrapie. 895 91
Because the urinary bladder stores and releases urine, its normal function includes filling and emptying, accompanied by distension and relaxation. It is known that chronic distension compromises blood flow. Recent studies of the rabbit bladder vasculature have described specializations of that vasculature that appear to enhance blood flow in the bladder wall during distension. The present report describes the location, orientation, and structure of an elastic sheath surrounding the vesicular arteries, which may represent one of these specializations. The location, vasculature, and structure of an accessory elastic sheath surrounding the vesicular arteries of the rabbit bladder is described using light and electron microscopy, India ink injection, and vascular corrosion casting. The common iliac arteries of rabbits were cannulated to permit perfusion of the distal vasculature including the urinary bladder. After the bladder vasculature was visually cleared of blood by perfusion with buffered saline, one of the following procedures was used: 1) for light or electron microscopy, the bladder was perfuse-fixed with buffered 2% glutaraldehyde; 2) the bladder vasculature was filled with India ink for vessel tracing; or 3) corrosion casts of the bladder vasculature were prepared by infusion of a Mercox resin mixture. Casts, cleaned of tissue with KOH, and water and
formic acid
rinses, are dried, and mounted for routine scanning electron microscopy. The presence of an accessory sheath surrounding the main vesicular arteries and some of their branches in the basal two thirds of the urinary bladder was observed on India ink injected specimens and confirmed by micrographs and vascular corrosion casts. The sheath consists of elastic and collagenous fibers and is separated from the tunica media of the arteries by a loose connective tissue layer of variable width. The sheath is circumscribed by a layer of fine blood vessels. The vesicular arteries undulate within the sheath to an extent which is dependent upon the degree of distension of the bladder. This sheath likely represents a specialization which permits the bladder vasculature to accommodate expansion and contraction of the wall during normal filling and emptying. Undulations or coiling of the vesicular arteries within the loose connective tissue core of the sheath increase with bladder contraction, and apparently the sheath simply holds the artery in position during such coiling. The sheath, may represent a modification of the external elastic lamina found in some muscular arteries.
Anat
Rec
1998 11
PMID:Evidence for a unique elastic sheath surrounding the vesicular arteries of the rabbit urinary bladder--studies of the microvasculature with microscopy and vascular corrosion casting. 981 Dec 25
The urinary bladder is especially subject to infection by virtue of its direct connection to the external urethral opening, and it is natural to anticipate the presence of a well-developed immunological mechanism to respond to this potential threat. The present study describes small, very highly vascular lymph nodes located in the wall of the rabbit bladder, which may be involved in a local response to foreign antigens. The vasculature and structure of these lymph nodes was described using a combination of vascular corrosion casting, ink injection, and light and electron microscopy. The distal abdominal aorta was cannulated, and after clearing the bladder vasculature with buffered saline, one of the following procedures was used: 1) the bladder was perfuse-fixed in preparation for light and electron microscopy; 2) the bladder vasculature was filled with India ink for vessel tracing; or 3) vascular corrosion casts of the vasculature were prepared by infusing resin comprised of a mixture of Mercox, methyl methacrylate monomer, and catalyst. The resulting casts were cleaned with KOH,
formic acid
, and water in preparation for scanning electron microscopy. Vascular casts and India ink injections revealed the presence of a number of isolated capillary tufts consisting of clusters of one to five "glomeruli," closely associated with the major vesicular vessels along the lateral walls of the bladder, and supplied by tertiary branches of these vessels. Light and electron microscopy showed that the capillary tufts represented the blood supply to small, ovoid lymph nodes located near the serosal surface of the bladder wall and usually restricted to the basal half of the bladder. These nodes were encapsulated and exhibited subcapsular sinuses, numerous small blood vessels, a limited number of high endothelial cells, and, occasionally, nerves and a follicular substructure. The nodes contained abundant lymphocytes, stellate stromal cells, macrophages, and eosinophils, but lacked the obvious cortical and medullary organization and germinal centers often seen in larger lymph nodes. Vascular corrosion casts, vascular ink injections, and microscopic examination confirmed the presence of small, highly vascular lymph nodes closely associated with the main vesicular vessels along the lateral walls of the rabbit bladder. A follicular substructure of the nodes appears to correspond with the "glomerular" capillary arrangement within the nodes as seen with corrosion casts. The rich blood supply may be indicative of the high metabolic demand of lymphatic tissue, and may be altered in response to the level of activity of the node. The close association between the lymphatic tissue and the rich blood supply to the nodes may allow a rapid mobilization of lymphocytes during a local immune response to foreign agents.
Anat
Rec
1998 11
PMID:Structure and blood supply of intrinsic lymph nodes in the wall of the rabbit urinary bladder--studies with light microscopy, electron microscopy, and vascular corrosion casting. 981 Dec 26
The vascular system of the urinary bladder wall effectively performs its function in spite of considerable spatial changes due to the filling/voiding cycle. However, only a few studies have dealt with the microvascular architecture of the bladder wall and only two, using old-fashioned techniques, were devoted to the human bladder. This study presents the microvasculature of the human bladder wall visualized by scanning electron microscopy of vascular corrosion casts. Postoperative bladder specimens obtained from patients with advanced bladder tumors were filled with small amount (80 ml) of saline and perfused via at least four largest arteries with anticoagulant-containing saline followed by paraformaldehyde/glutaraldehyde fixative and Mercox resin. After polymerization of the resin, the vascular casts were macerated with potassium hydroxide, cleaned with
formic acid
and water and freeze dried. Only regions of the bladder wall distant to the tumor were examined in light and scanning electron microscopes. The almost empty state of the bladder was manifested by extensive folding of the mucosa and tortuosity of almost all vessels other than capillaries. The branches of main arteries and veins formed an adventitial/serosal plexus which directly supplied/drained the capillary network of the muscularis and sent long perpendicular vessels to the mucosal plexus. These vessels had straight or coiled course depending on whether they terminated at the top or at the base of the mucosal folds. The rich mucosal plexus followed the folds parallel to their surface and gave off short, straight, mostly perpendicular twigs communicating with the subepithelial capillary network. Apart from very few vascular interconnections between the mucosal plexus and the muscularis, the submucosa was generally avascular. The subepithelial capillary network showed extreme density and uneven contours of the capillaries, only in less folded areas of trigone and urethral orifice the network was looser and capillaries thinner. The capillary system of the muscularis was poorly developed. Due to its architecture, tortuosity, and coiling/uncoiling capabilities, the microvasculature of the human urinary bladder wall seems to efficiently accommodate changes associated with cyclic contraction and stretching. Disturbances in blood flow induced by overdistension of the bladder reported in several studies may be due to pressure of the urine affecting the patency of the vessels rather than to the spatial insufficiency of the vascular system.
Anat
Rec
1999 03
PMID:Microvascular architecture of the human urinary bladder wall: a corrosion casting study. 1009 69
A changeable ligand, which involves in activation of a catalyst or assists a reaction, draws an increasing attention, in contrast to a classical ligand as spectator. Proton-responsive catalysts, which are capable of undergoing changes of properties on gaining/losing one or more protons, provides interesting features as follows: (i) catalyst activation by electronic effect, (ii) pH-tuning of water-solubility, and (iii) second-coordination-sphere interaction. On the basis of this catalyst design concept, we developed several highly efficient proton-responsive catalysts for CO
2
hydrogenation as H
2
storage,
formic acid
(FA) dehydrogenation as H
2
production, and transfer hydrogenation. The transformable ligands of proton-responsive catalysts in promoting effective catalysis have aroused our interest. In this account, we summarize our efforts for the development and application of proton-responsive catalysts. Specifically, the important role of pH-dependent proton-responsive complexes will be discussed.
Chem
Rec
2017 11
PMID:Development of Proton-Responsive Catalysts. 2865 May 71
Homogeneous metal complex and salt catalysts were developed for the reductive transformation of CO
2
with Si-based reducing agents. Cu-bisphosphine complexes were found to be excellent catalysts for the hydrosilylation of CO
2
with polymethylhydrosiloxane (PMHS). The Cu complexes also showed high catalytic activity and a wide substrate scope for formamide synthesis from amines, CO
2
, and PMHS. Simple fluoride salts such as tetrabutylammonium fluoride acted as good catalysts for the reductive conversion of CO
2
to
formic acid
in the presence of hydrosilane, disilane, and metallic Si. Based on the kinetics, isotopic experiments, and in-situ NMR measurements, the reaction mechanism for both catalyst systems, the Cu complex and the fluoride salt, have been proposed.
Chem
Rec
2019 Jul
PMID:Efficient Conversion of Carbon Dioxide with Si-Based Reducing Agents Catalyzed by Metal Complexes and Salts. 3025 93
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