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51.
52.
Additions and changes have been introduced into the existing antigenic diagnostic scheme of P. rettgeri on the basis of the study of the antigenic structure of standard strains from foreign collections: new, formerly unknown varieties of somatic and flagellar antigens (O35, O36, H27, H28) have been discovered, the complex of antigenic factors for H-antigens 7, 10, 23, 27 has been discovered. Strains 958 (36 : 28) and 979 (16 : 27a, 23b, 2a), previously classified with the genus Morganella, have been identified by O- and H-antigens. 相似文献
53.
Romanenko V Nakamoto T Srivastava A Melvin JE Begenisich T 《The Journal of biological chemistry》2006,281(38):27964-27972
The physiological success of fluid-secreting tissues relies on a regulated interplay between Ca(2+)-activated Cl(-) and K(+) channels. Parotid acinar cells express two types of Ca(2+)-activated K(+) channels: intermediate conductance IK1 channels and maxi-K channels. The IK1 channel is encoded by the K(Ca)3.1 gene, and the K(Ca)1.1 gene is a likely candidate for the maxi-K channel. To confirm the genetic identity of the maxi-K channel and to probe its specific roles, we studied parotid glands in mice with the K(Ca)1.1 gene ablated. Parotid acinar cells from these animals lacked maxi-K channels, confirming their genetic identity. The stimulated parotid gland fluid secretion rate was normal, but the sodium and potassium content of the secreted fluid was altered. In addition, we found that the regulatory volume decrease in acinar cells was substantially impaired in K(Ca)1.1-null animals. We examined fluid secretion from animals with both K(+) channel genes deleted. The secretion rate was severely reduced, and the ion content of the secreted fluid was significantly changed. We measured the membrane potentials of acinar cells from wild-type mice and from animals with either or both K(+) channel genes ablated. They revealed that the observed functional effects on fluid secretion reflected alterations in cell membrane voltage. Our findings show that the maxi-K channels are critical for the regulatory volume decrease in these cells and that they play an important role in the sodium uptake and potassium secretion process in the ducts of these fluid-secreting salivary glands. 相似文献
54.
Baturo AP Romanenko EE Mokronosova MA 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》2006,(7):82-85
Microflora of nasopharynx in 117 patients with urticaria was studied. 589 cultures of gram-negative and Gram-positive bacteria were isolated. Gram-positive bacteria represented the overwhelming majority of isolates from which streptococci dominated with high level of constancy (C=91.4%) and prevalence on mucosa. Several patients had signs of chronic streptococcal infection that support the possible role of streptococci in development of urticaria. 相似文献
55.
Tetsuji Nakamoto David A. Brown Marcelo A. Catal��n Mireya Gonzalez-Begne Victor G. Romanenko James E. Melvin 《The Journal of biological chemistry》2009,284(8):4815-4822
Salivary glands express multiple isoforms of P2X and P2Y nucleotide
receptors, but their in vivo physiological roles are unclear. P2
receptor agonists induced salivation in an ex vivo submandibular
gland preparation. The nucleotide selectivity sequence of the secretion
response was BzATP ≫ ATP > ADP ≫ UTP, and removal of external
Ca2+ dramatically suppressed the initial ATP-induced fluid
secretion (∼85%). Together, these results suggested that P2X receptors are
the major purinergic receptor subfamily involved in the fluid secretion
process. Mice with targeted disruption of the P2X7 gene
were used to evaluate the role of the P2X7 receptor in
nucleotide-evoked fluid secretion. P2X7 receptor protein and
BzATP-activated inward cation currents were absent, and importantly,
purinergic receptor agonist-stimulated salivation was suppressed by more than
70% in submandibular glands from P2X7-null mice.
Consistent with these observations, the ATP-induced increases in
[Ca2+]i were nearly abolished in
P2X7–/– submandibular acinar and
duct cells. ATP appeared to also act through the P2X7 receptor to
inhibit muscarinic-induced fluid secretion. These results demonstrate that the
ATP-sensitive P2X7 receptor regulates fluid secretion in the mouse
submandibular gland.Salivation is a Ca2+-dependent process
(1,
2) primarily associated with
the neurotransmitters norepinephrine and acetylcholine, release of which
stimulates α-adrenergic and muscarinic receptors, respectively. Both
types of receptors are coupled to G proteins that activate phospholipase
Cβ (PLCβ) during salivary gland stimulation. PLCβ activation
cleaves phosphatidylinositol 1,4-bisphosphate resulting in diacylglycerol and
inositol 1,4,5-trisphosphate (InsP3) production. Activation of
Ca2+-selective InsP3 receptor channels localized to the
endoplasmic reticulum of salivary acinar cells increases the intracellular
free calcium concentration
([Ca2+]i).4
Depletion of the endoplasmic reticulum Ca2+ pool triggers
extracellular Ca2+ influx and a sustained elevation in
[Ca2+]i. This increase in
[Ca2+]i activates Ca2+-dependent
K+ and Cl– channels promoting Cl–
secretion across the apical membrane and a lumen negative, electrochemical
gradient that supports Na+ efflux into the lumen. The accumulation
of NaCl creates an osmotic gradient which drives water movement into the
lumen, thus generating isotonic primary saliva. This primary fluid is then
modified by the ductal system, which reabsorbs NaCl and secretes
KHCO3 producing a final saliva that is hypotonic
(1,
2).Salivation also has a non-cholinergic, non-adrenergic component, the origin
of which is unclear (3). In
addition to muscarinic and α-adrenergic receptors, salivary acinar cells
express other receptors that are coupled to an increase in
[Ca2+]i such as purinergic P2 and substance P
receptors. Like muscarinic and α-adrenergic receptors, P2 receptor
activation leads to a sustained increase in
[Ca2+]i in salivary acinar cells
(4). In contrast, substance P
receptor activation rapidly desensitizes and therefore generates only a
relatively transient increase in [Ca2+]i
(5) that is unlikely to
appreciably contribute to fluid secretion. The purinergic P2 receptor family
is comprised of G protein-coupled P2Y and ionotropic P2X receptors activated
by extracellular di- and triphosphate nucleotides. Activation of both
subfamilies of P2 receptors causes an increase in
[Ca2+]i. P2Y receptors increase
[Ca2+]i via InsP3-induced
Ca2+ mobilization from intracellular stores (similar to
α-adrenergic and muscarinic receptors) while P2X receptors act as
ligand-gated, non-selective cation channels that mediate extracellular
Ca2+ influx (6).
Salivary gland tissues express at least four isoforms of P2X (P2X4
and P2X7) and P2Y (P2Y1 and P2Y2) subtypes;
however, their in vivo physiological significance has yet to be
characterized
(7–11).Our results revealed that ATP acts in isolation to stimulate fluid
secretion from the mouse submandibular gland, but secretion is inhibited when
ATP is simultaneously presented with a muscarinic receptor agonist. Ablation
of the P2X7 gene had no effect on the salivary flow rate
evoked by muscarinic receptor activation, but markedly reduced ATP-mediated
fluid secretion and rescued the inhibitory effects of ATP on muscarinic
receptor activation. Submandibular gland acinar cells from
P2X7–/– animals had dramatically
impaired ATP-activated Ca2+ signaling, consistent with this being
the mechanism responsible for the reduction in ATP-mediated fluid secretion in
these mice. Together, these results demonstrated that ATP regulates
salivation, acting mainly through the P2X7 receptor. Activation of
the P2X7 receptor may play a major role in non-adrenergic,
non-cholinergic stimulated fluid secretion. 相似文献
56.
Bakloushinskaya I. Yu. Romanenko S. A. Graphodatsky A. S. Matveevsky S. N. Lyapunova E. A. Kolomiets O. L. 《Russian Journal of Genetics》2010,46(9):1143-1145
Modern mole voles of the genus Ellobius are characterized by species-specific features of autosomes and sex chromosomes. Owing to the use of the Zoo-FISH method,
the nomenclature of chromosomes was refined and nonhomologous Robertsonian translocations indistinguishable by G-staining
were identified for Ellobius tancrei, which is a species with a wide chromosome variation of the Robertsonian type. The electron-microscopic analysis of synaptonemal
complexes in F1 hybrids of forms with 2n = 50 and 2n = 48 revealed the formation of a closed SC-pentavalent composed of three metacentrics with monobrachial homology and two
acrocentrics. Segregation of chromosomes of such complex systems is impeded by disturbances in the nucleus architecture leading
to the formation of unbalanced gametes and to a dramatic reduction in fertility of hybrids. Our data support the hypothesis
that the formation of monobrachial homologous metacentric chromosomes can be considered as a way of chromosomal speciation. 相似文献
57.
Byfield FJ Aranda-Espinoza H Romanenko VG Rothblat GH Levitan I 《Biophysical journal》2004,87(5):3336-3343
This study has investigated the effect of cellular cholesterol on membrane deformability of bovine aortic endothelial cells. Cellular cholesterol content was depleted by exposing the cells to methyl-beta-cyclodextrin or enriched by exposing the cells to methyl-beta-cyclodextrin saturated with cholesterol. Control cells were treated with methyl-beta-cyclodextrin-cholesterol at a molar ratio that had no effect on the level of cellular cholesterol. Mechanical properties of the cells with different cholesterol contents were compared by measuring the degree of membrane deformation in response to a step in negative pressure applied to the membrane by a micropipette. The experiments were performed on substrate-attached cells that maintained normal morphology. The data were analyzed using a standard linear elastic half-space model to calculate Young elastic modulus. Our observations show that, in contrast to the known effect of cholesterol on membrane stiffness of lipid bilayers, cholesterol depletion of bovine aortic endothelial cells resulted in a significant decrease in membrane deformability and a corresponding increase in the value of the elastic coefficient of the membrane, indicating that cholesterol-depleted cells are stiffer than control cells. Repleting the cells with cholesterol reversed the effect. An increase in cellular cholesterol to a level higher than that of normal cells, however, had no effect on the elastic properties of bovine aortic endothelial cells. We also show that although cholesterol depletion had no apparent effect on the intensity of F-actin-specific fluorescence, disrupting F-actin with latrunculin A abrogated the stiffening effect. We suggest that cholesterol depletion increases the stiffness of the membrane by altering the properties of the submembrane F-actin and/or its attachment to the membrane. 相似文献
58.
Kilcoyne M Perepelov AV Tomshich SV Komandrova NA Shashkov AS Romanenko LA Knirel YA Savage AV 《Carbohydrate research》2004,339(3):477-482
Mild acid degradation of the lipopolysaccharide of the bacterium Idiomarina zobellii, type strain KMM 231T, with aq 2% HOAc at 100 degrees C, yielded an oligosaccharide, which represents one repeating unit of the O-polysaccharide. A polysaccharide was obtained by mild base degradation of the lipopolysaccharide. The following structure of the O-polysaccharide was elucidated by 1H and 13C NMR spectroscopy of the oligosaccharide and base-degraded lipopolysaccharide, including COSY, TOCSY, ROESY, 1H, 13C HSQC, HSQC-TOCSY and HMBC experiments: [-->3)-alpha-D-Quip4N-(1-->4)-alpha-D-GlcpA-(1-->6)-alpha-D-GlcpNAc-(1-->4)-alpha-L-GulpNA-(1-->3)-beta-D-FucpNAc-(1-->] The O-polysaccharide is distinguished by the presence of two unusual amino sugars, 4-amino-4,6-dideoxy-D-glucose (D-Qui4N) and 2-amino-2-deoxy-L-guluronic acid (L-GulNA), both having the free amino group. The unexpectedly high acid lability of the glycosidic linkage of 2-acetamido-2,6-dideoxy-D-galactose (D-FucNAc) could be associated with the presence of a free amino group adjacent to the site of attachment of FucNAc to Qui4N. 相似文献
59.
Kalinovskaya NI Kuznetsova TA Ivanova EP Romanenko LA Voinov VG Huth F Laatsch H 《Marine biotechnology (New York, N.Y.)》2002,4(2):179-188
A marine bacterium (KMM 1364), identified as Bacillus pumilus, was isolated from the surface of ascidian Halocynthia aurantium. Structural analysis revealed that the strain KMM 1364 produced a mixture of lipopeptide surfactin analogs with major components
with molecular masses of 1035, 1049, 1063, and 1077. The variation in molecular weight represents changes in the number of
methylene groups in the lipid and/or peptide portions of the compounds. Structurally, these lipopeptides differ from surfactin
in the substitution of the valine residue in position 4 by leucine, and have been isolated as two carboxy-terminal variants,
with valine or isoleucine in position 7. As constituents of the lipophilic part of the peptides, only β-hydroxy-C15-, β-hydroxy-C16-, and a high amount of β-hydroxy-C17 fatty acid were determined. 相似文献
60.
Gorshkova RP Nazarenko EL Isakov VV Zubkov VA Gorshkova NM Romanenko LA Ivanova EP 《Bioorganicheskaia khimiia》1998,24(11):839-841
On the basis of acid hydrolysis, dephosphorylation, methylation, and 13C NMR spectroscopy data, the O-specific polysaccharide of Pseudoalteromonas sp. KMM 639 was shown to be a glycerophosphate-containing polymer built of repeating disaccharide units of the following structure: [formula: see text] 相似文献