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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Experiment I was designed to determine if cell-free synchronous uterine flushings contain an embryotoxic substance that is normally screened by the intact zona pellucida. Sixty 4-cell embryos were allocated to three treatment groups: 1) control embryos (n = 20) were cultured in Modified Kreb's Ringer Bicarbonate medium + 10% bovine calf serum (mKRB-BCS), 2) UF embryos (n = 20) were cultured in 80% mKRB-BCS + 20% sterile dialyzed uterine flushings (UF), 3) MicroUF embryos (n = 20) received a microsurgical incision in the zona pellucida and were cultured in 80% mKRB-BCS + 20% UF. Following 72 h in culture at 37 degrees C under a 90% N2, 5% CO2, and 5% O2 atmosphere, the number of nuclei/embryo and the incidence of protrusion of the trophoblast through the zona pellucida (PTZ) were recorded. Addition of UF had no effect on embryo development. A greater (P less than .005) proportion of MicroUF embryos exhibited PTZ as compared to UF and control embryos. Experiment II was devised to further characterize the occurrence of PTZ in Micro porcine embryos. Thirty-three 4- to 10-cell embryos and 14 morulae were distributed across two treatments: 1) control embryos (n = 16 and 6, respectively) were cultured as described in Experiment I; and 2) micro embryos were treated similarly to MicroUF embryos in Experiment I but were cultured in mKRB-BCS only. At the onset of PTZ, embryos were immediately fixed and examined. The proportion of embryos exhibiting PTZ was greater (P less than .007) for Micro versus control embryos.(ABSTRACT TRUNCATED AT 250 WORDS)
Mol Reprod Dev 1991 Oct
PMID:Effect of cell-free synchronous uterine flushings and microsurgery on the development of porcine embryos in vitro. 195 24

The effect of tumor necrosis factor-alpha (TNF) on hyperoxia-induced endothelial injury in vitro was investigated. TNF caused a time- and dose-dependent reduction in the number of viable pulmonary artery endothelial cells. The TNF-mediated endothelial cytotoxicity was more pronounced under hyperoxia (95% O2 and 5% CO2) than under normoxia (95% air and 5% CO2). Pretreatment of endothelial cells with TNF (0.01 micrograms/ml or 240 U/ml) for 18 h at normoxia reduced the intracellular concentration of total glutathione (GSH), whereas the concentration of oxidized GSH was increased. These TNF-treated endothelial cells were more susceptible to hyperoxia- or hydrogen peroxide-mediated cytotoxicity. TNF also induced changes in endothelial morphology and in the distribution and density of actin filaments. Exogenous GSH or L-2-oxothiazolidine-4-carboxylate, which enhanced endothelial GSH concentrations, partially protected endothelial cells against TNF-mediated cytotoxicity, morphologic changes, and actin filament redistribution, especially under the hyperoxic condition. These results suggest an important role of GSH in modulating endothelial response to TNF.
Am J Respir Cell Mol Biol 1991 Dec
PMID:Tumor necrosis factor enhances endothelial cell susceptibility to oxygen toxicity: role of glutathione. 195 83

The petunia nuclear gene which encodes the chloroplast isozyme of superoxide dismutase, SOD-1, has been fused with an efficient rbcS promoter fragment and 3' flanking region and introduced into tobacco and tomato cells. Transformed plants carrying this chimeric gene have up to 50-fold the levels of SOD-1 which occur in wild-type plants. However, tobacco plants with 30- to 50-fold the normal SOD-1 activity do not exhibit resistance to the light-activated herbicide paraquat. Similarly, tomato plants with 2- to 4-fold increases in SOD-1 do not exhibit tolerance to photoinhibitory conditions known to increase superoxide levels (high light, low temperatures and low CO2 concentrations). Our data indicate that increasing the chloroplastic SOD level in a plant cell is not sufficient to reduce the toxicity of superoxide.
Plant Mol Biol 1990 Apr
PMID:Transformed plants with elevated levels of chloroplastic SOD are not more resistant to superoxide toxicity. 196 84

This study describes the effects of CO2 laser radiation on the histology of the normal rabbit arterial wall, using models that simulate laser angioplasty and anastomosis. Rabbit arteries were exposed to laser treatments similar to those used clinically; 40, 0.5 sec pulses of 40-60 mW, CO2 continuous wavelength laser, or a 1/2-circumferential laser anastomosis with a 60-80 mW continuous pulse. Aneurysms developed in 8 of 22 femoral, 1 of 22 carotid, and no controls at 12 week. There were small breaks in the internal elastic lamina with atrophy, loss of muscularis, "packing" of the elastica, thinning of the muscularis at the damage site, and enlargement of the arterial diameter. Aneurysms developed in one femoral and no carotid anastomosed artery. Laser anastomoses demonstrated more muscle damage and loss, with extensive scarring and a wider area of elastic loss than the controls. The intima was reestablished with focal reduplication of the internal elastic lamina. There were no histologic differences between the arteries which developed aneurysms and those which did not in either series. These results suggest that low power laser damage of the arterial wall consists mainly of destruction of the muscularis propria, with minimal damage to the elastica.
Virchows Arch B Cell Pathol Incl Mol Pathol 1990
PMID:CO2-laser radiation damage of the arterial wall. 197 23

The exact functional role of the zinc hydroxide (water)-Thr199-Glu106 hydrogen bond network in the carbonic anhydrases is unknown. However, from the results of molecular dynamics simulations (MD) we are able to better define its function. From computer graphics analysis and MD simulations on the zinc hydroxide form of human carbonic anhydrase II we find that this interaction forces the hydroxide hydrogen atom to be in a "down" position relative to the deep water-binding pocket. From previous work we have found that this pocket is a high-affinity binding site for CO2. We also note that during the timescale of our simulation (126 ps) the hydrogen bonds between the hydroxide hydrogen atom and Thr199 and the one between Thr199 and Glu106 are not fluxional. We propose that the role of the zinc hydroxide (water)-Thr199-Glu106 hydrogen bond network is to lock the hydrogen atom in the down position in order to expose the CO2 molecule bound in the deep water pocket to a lone pair of the hydroxide oxygen atom. This would allow for the rapid reaction of the CO2 molecule around the zinc ion. Furthermore, if the hydroxide hydrogen atom were not locked in the down position the binding of CO2 to the deep water pocket could be interfered with by the unrestrained hydroxide hydrogen atom (e.g. the N-Zn-O-H torsion could undergo rotational transitions that would partially block the deep water pocket). In summary, the roles we ascribe to this hydrogen bonding network are (1) to allow for facile access of CO2 to the deep water pocket and (2) to allow for maximal exposure of a hydroxide oxygen lone pair to the CO2 carbon atom.
J Mol Biol 1990 Aug 20
PMID:Insights into the function of the zinc hydroxide-Thr199-Glu106 hydrogen bonding network in carbonic anhydrases. 197 31

Glutamate in glutamatergic neurons exists in a cytosolic pool, as well as a transmitter pool, which is assumed to be localized in synaptic vesicles. Transmitter glutamate released from glutamatergic neurons is taken up by both neurons and glial cells, giving rise to a flux of glutamate from neurons to astrocytes. In astrocytes, glutamine is formed from glutamate by the glial-specific enzyme glutamine synthetase (EC 6.3.1.2). Glutamine diffuses back to neurons, where glutamate is formed by phosphate-activated glutaminase (EC 3.5.1.2). However, this cycle is not stoichiometric, and glutamine obtained from glial cells cannot replenish all transmitter glutamate lost from neurons. 2-Oxoglutarate is another putative precursor for transmitter glutamate. Net synthesis of citric acid cycle intermediates is dependent on carbon dioxide fixation to pyruvate, catalyzed by pyruvate carboxylase (EC 6.4.1.1). Since this enzyme is exclusively glial, a net flow of citric acid cycle intermediates from glial cells to neurons probably exists. The quantitative contribution of each transmitter precursor may not be the same in different regions of the brain and may vary with the metabolic state of the neuron. The pool of transmitter glutamate is most likely regulated by the activity of glutamate-forming enzymes in the nerve terminal, and/or by uptake/release of glutamate and glutamate precursors through the synaptosomal plasma membrane.
Mol Chem Neuropathol 1990 Jan
PMID:Synthesis of transmitter glutamate and the glial-neuron interrelationship. 198 May 84

The exposure of the cephalic end of rats to repeated doses of X-irradiation (150 rad) immediately after birth induces a long-term increase in the noradrenaline (NA) content of cerebellum (CE) (+ 37.8%), and a decrease in cerebellar weight (65.2% of controls), which results in an increased NA concentration (+ 109%). This increase in the neurotransmitter level is accompanied by a dystonic syndrome and histological abnormalities: Purkinje cells (the target cells for NA afferents to CE) fail to arrange in a characteristic monolayer, and their primary dendritic tree appears randomly oriented. The injection of reserpine 0.9 and 1.2 mg/kg ip to adult rats for 18 h depletes cerebellar NA content in both controls (15.7 +/- 4 ng/CE and 2.8 +/- 1.5 ng/CE, respectively) and X-irradiated rats (17.1 +/- 1 ng/CE and 8.3 +/- 2 ng/CE, respectively). The activity of tyrosine hydroxylase (TH) in CE of adult rats, measured by an in vitro assay, is significantly increased in neonatally X-irradiated animals when compared to age-matched controls (16.4 +/- 1.4 vs 6.32 +/- 0.6 nmol CO2/h/mg prot., p less than 0.01). As observed for NA levels, a net increase in TH activity induced by the ionizing radiation is also measured: 308.9 +/- 23.8 vs 408.2 +/- 21.5 nmol CO2/h/CE, p less than 0.01 (controls and X-treated, respectively). These results suggest that X-irradiation at birth may induce an abnormal sprouting of noradrenergic afferents to CE. The possibility that these changes represent a response of the NA system to the dystonic syndrome is discussed.
Mol Chem Neuropathol
PMID:Increased activity of tyrosine hydroxylase in the cerebellum of the X-irradiated dystonic rat. 198 78

These studies were conducted to examine activation of in vitro-matured porcine oocytes in response to an electrical stimulus or to an ionophore. Cumulus-enclosed porcine oocytes were incubated in maturation medium supplemented with either FSH and LH (MM:Exp.1) or pregnant mare serum gonadotropin (PMSG; MM-P: experiments 2-4) at 39 degrees C in 5% CO2:95% air with high humidity. In experiment 1, groups of oocytes were stripped of cumulus and then shampulsed (control) or electrically pulsed with a Zimmerman Cell Fusion unit at 24, 31, 41, 48, and 65 h of incubation. Control oocytes were exposed to the activation medium for 20 sec, whereas oocytes to be pulsed were subjected to a single activation pulse (120 V, 30 microseconds). Oocytes were cultured for an additional 24 h and then fixed and examined. For oocytes pulsed at 24, 31, 41, 48, and 65 h, the proportions which activated were 0, 0, 87, 88, and 83%, respectively. In experiment 2, oocytes were electrically or sham-pulsed with a BTX 200 Embryomanipulation System at 24, 30, and 40 h of incubation and respective proportions of oocytes activating were 27%, 39%, and 72%. In experiment 3, oocytes were subjected to 0, 1, or 2 activation pulses after 41 h of incubation in MM-P. Double-pulsing halved the proportion of activated oocytes (P less than .0001). In experiment 4, oocytes were subjected to 0, 25, 50, or 100 microM ionophore at 48 h of incubation. Proportions of oocytes activated by ionophore were greater than for control (P less than .05), but activation was not increased by increasing dose of ionophore.(ABSTRACT TRUNCATED AT 250 WORDS)
Mol Reprod Dev 1991 Jan
PMID:Response of porcine oocytes to electrical and chemical activation during maturation in vitro. 199 82

Post mitochondrial supernatants (S-12 extracts) were prepared from Phycomyces blakesleeanus by grinding washed and frozen mycelial cakes in fine sand and extracting the paste produced with buffer containing Tris-HCl pH 7.8 (0.1 M), EDTA (0.01 M), dithiothreitol (5 mM) and glycerol (10% v/v). The S-12 extracts, obtained in this way, reproducibly hydroxylated progesterone, producing 7 alpha- and 15 beta-hydroxyprogesterone the major products of whole-cell transformation. Cell-free progesterone hydroxylation was found to be approximately linearly dependent on extract concentration, to require reduced NADP (partly replaceable by NADH), and to be dependent on progesterone (apparent Km calculated to be 4 mM). K+ and Mg2+ were found not to be required. Maximum progesterone hydroxylation occurred after 2 h at pH 7.8 and at 24 degrees C. Using optimum conditions S-12 extracts were capable of hydroxylating between 5 and 15% of added progesterone (0.2 mM). Hydroxylation was found to be partially inhibited by carbon monoxide (ca 40%) and almost completely inhibited by azoles, ketoconazole and diconazole. The NADPH and molecular oxygen requirements were replaceable by NaIO4. These findings strongly suggest that hydroxylation was being catalyzed by cytochrome P-450. This was confirmed by preparing progesterone-hydroxylating microsomes and Triton N-101-solubilized microsome extracts, and by obtaining a dithionite-reduced carbon monoxide-difference absorption spectrum peak at 455 nm in the solubilized microsome extracts.
J Steroid Biochem Mol Biol 1991 Feb
PMID:Microbial transformation of steroids--VII. Hydroxylation of progesterone by extracts of Phycomyces blakesleeanus. 200 46

Fertilizing competency of multiple ovulated eggs in the domestic fowl was examined by fertilization in vitro and early development in culture. Normal laying hens (White Leghorn) were treated with 75 IU of PMSG for 7 days followed by injection of anterior pituitary extracts from chickens (CAPE). Ovulation began to occur 7.5 h after injection of CAPE. These hens ovulated 1-7 ova but some premature ovulation of GV stage ova were observed. In vitro fertilization of the multiple ovulated ova was examined by inseminating 10(6)-10(7) sperm onto the germinal disks in m-Ringer's solution. The gamete or zygote nuclei were detected by DNA specific fluorescence using DAPI (4',6'-diamidino-2-phenylindole) in the histological section prepared from the germinal disk. Process of fertilization was examined in the eggs incubated for 4 h after insemination in DMEM + liquid albumen at 41 degrees C under the atmosphere of 5% CO2 in air. Fertilization rate of the total multiple ovulated eggs was 55% (11/20), in which 90% (9/10) and 10% (1/10) in the eggs recovered 7.5-8.5 h and 9.0-9.5 h after CAPE injection were obtained, respectively. Normal pronuclei were formed in five eggs of those recovered 7.5-8.5 h after CAPE injection. Early development after fertilization in vitro was also examined by incubation for 12 h in DMEM + liquid albumen at 41 degrees C under the atmosphere of 5% CO2 in air. Although development in vitro was delayed compared to that in utero condition, normal development was observed in naturally and multiple ovulated eggs.(ABSTRACT TRUNCATED AT 250 WORDS)
Mol Reprod Dev 1991 Feb
PMID:Fertilizing competency of multiple ovulated eggs in the domestic fowl (Gallus domesticus). 200 27


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