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7242ec22-7fe9-494b-a7c9-1222815ae523
| 4 |
These results indicate that affinities of ferric myoglobin for ligands, in contrast to those of the ferrous form for oxygen and carbon monoxide (Sono, M., and Asakura, T. (1975) J. Biol. Chem. 250, 5527-5232 and Sono, M., Smith, P.D., McCray, J.
|
7242ec22-7fe9-494b-a7c9-1222815ae523
| 5 |
A., and Asakura, T. (1976) J. Biol. Chem 251, 1418-1426), are not affected by the position of modifications at the two vinyl groups, but are determinedby the number of the formyl groups and that two vinyl groups at position 2 and 4 are equivalent in the binding of various ligands by ferric myoglobin.
|
7242ec22-7fe9-494b-a7c9-1222815ae523
| 6 |
The electron density of the ferric iron appears to be similar for the two isomeric monoformyl-monovinylmyoglobins.
|
046b9dcc-8cfe-447e-8433-e8d5241bcb3f
| 0 |
An essential residue at the active site of aspartate transcarbamylase. Reaction of phenylglyoxal with aspartate transcarbamylase and its isolated catalytic subunit results in complete loss of enzymatic activity. This modification reaction is markedly influenced by pH and is partially reversible upon dialysis. Carbamyl phosphate or carbamyl phosphate with succinate partially protect the catalytic subunit and the native enzyme from inactivation by phenylglyoxal.
|
046b9dcc-8cfe-447e-8433-e8d5241bcb3f
| 1 |
In the native enzyme complete protection from inactivation is afforded by N-(phosphonacetyl)-L-aspartate. The decrease in enzymatic activity correlates with the modification of 6 arginine residues on each aspartate transcarbamylase molecule, i.e. 1 arginine per catalytic site. The data suggest that the essential arginine is involved in the binding of carbamyl phosphate to the enzyme.
|
046b9dcc-8cfe-447e-8433-e8d5241bcb3f
| 2 |
Reaction of the single thiol on the catalytic chain with 2-chloromercuri-4-nitrophenol does not prevent subsequent reaction with phenylglyoxal. If N-(phosphonacetyl)-L-aspartate is used to protect the active site we find that phenylglyoxal also causes the loss of activation of ATP and inhibition by CTP.
|
046b9dcc-8cfe-447e-8433-e8d5241bcb3f
| 3 |
The rate of loss of heterotropic effects is exactly the same for both nucleotides indicating that the two opposite regulatory effects originate at the same location on the enzyme, or are transmitted by the same mechanism between the subunits, or both.
|
e5381fd3-4cb7-4272-89c9-6b07b1641c94
| 0 |
Physical and kinetic properties of homogenous bovine lens aldose reductase. Aldose reductase from calf lens was purified 15,000-fold. The homogeneity of the final preparation was demonstrated by molecular sieve chromatography, analytical ultracentrifugation, sodium dodecyl sulfate gel electrophoresis, Ouchterlony immunodiffusion, and polyacrylamide gel electrophoresis at three pH values.
|
e5381fd3-4cb7-4272-89c9-6b07b1641c94
| 1 |
The monomeric nature of the enzyme is suggested by the molecular weight of 37,000 from both molecular sieve chromatography and sodium dodecyl sulfate-gel electrophoresis with beta-mercaptoethanol. This closely corresponds with a molecular weight of 40,400 estimated by using calculate physical constants in the Svedberg equation.
|
e5381fd3-4cb7-4272-89c9-6b07b1641c94
| 2 |
The S20,w was 3.6 to 3.7 as determined from ultracentrifuge and sucrose density gradient data. The Stokes radius was found to be 2.5 +/- 0.2 nm and 2.75 +/- 0.15 nm by two different methods. The diffusion constant D20,w is (7.8 +/- 10(-7) +/- 0.45
|
e5381fd3-4cb7-4272-89c9-6b07b1641c94
| 3 |
X 10(-7) cm2/s). The molecule is nearly spherical as indicated by a frictional ratio f/fo = 1.14. The alpha-helical content was estimated from circular dichroism data to be 5% and did not change in the presence of added substrates, products, and some enzyme inhibitors.
|
e5381fd3-4cb7-4272-89c9-6b07b1641c94
| 4 |
Homotropic cooperative effects were observed as shown by the concave downward curvature of the reciprocal plots.
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c9c1d3c3-a6d9-4b32-aaa4-bb222f1b6972
| 0 |
L-Asparaginase of Klebsiella aerogenes. Activation of its synthesis by glutamine synthetase. An L-asparaginase has been purified some 250-fold from extracts of Klebsiella aerogenes to near homogeneity. The enzyme has a molecular weight of 141,000 as measured by gel filtration and appears to consist of four subunits of molecular weight 37,000.
|
c9c1d3c3-a6d9-4b32-aaa4-bb222f1b6972
| 1 |
The enzyme has high affinity for L-asparagine, with a Km below 10(-5) M, and hydrolyzes glutamine at a 20-fold lower rate, with a Km of 10(-3) M. Interestingly, the enzyme exhibits marked gamma-glutamyltransferase activity but comparatively little beta-aspartyl-transferase activity.
|
c9c1d3c3-a6d9-4b32-aaa4-bb222f1b6972
| 2 |
A mutant strain lacking this asparaginase has been isolated and grows at 1/2 to 1/3 the rate of the parent strain when asparagine is provided in the medium as the sole source of nitrogen. This strain grows as well as the wild type when the medium is supplemented with histidine or ammonia.
|
c9c1d3c3-a6d9-4b32-aaa4-bb222f1b6972
| 3 |
Glutamine synthetase activates the formation of L-asparaginase. Mutants lacking glutamine synthetase fail to produce the asparaginase, and mutants with a high constitutive level of glutamine synthetase also contain the asparaginase at a high level. Thus, the formation of asparaginase is regulated in parallel with that of other enzymes capable of supplying the cell with ammonia or glutamate, such as histidase and proline oxidase.
|
c9c1d3c3-a6d9-4b32-aaa4-bb222f1b6972
| 4 |
Formation of the asparaginase does not require induction by asparaginase and is not subject to catabolite repression.
|
94354f8a-a6b1-4bcd-944d-d631750cb5f6
| 0 |
Binding and degradation of insulin by human peripheral granulocytes. Demonstration of specific receptors with high affinity. The interaction of insulin with human circulating granulocytes was studied with the use of 125I-insulin. Human granulocytes, isolated from blood by the Böyum technique, showed high insulin-degrading activity in vitro which almost obscured the presence of specific, high affinity binding sites.
|
94354f8a-a6b1-4bcd-944d-d631750cb5f6
| 1 |
Degradation, measured by trichloroacetic acid precipitation and by binding to well characterized insulin receptors on cultured human lymphocytes (IM-9 line), was due to extracellular as well as cell-bound enzymes. Degradation was enhanced by Ca2+ and thiols and inhibited by various protease inhibitors and sulfhydryl-blocking reagents.
|
94354f8a-a6b1-4bcd-944d-d631750cb5f6
| 2 |
Phenylmethylsulfonyl fluoride (5 X 10(-4) M), a serine protease inhibitor, was the most potent and inhibited 125I-insulin degradation by 80 to 90%. Tert-butyl hydroperoxide (2 X 10(-3) M), a glutathione-oxidizing reagent, inhibited degradation by 35 to 50%, possibly due to an effect on a glutathione-insulin transhydrogenase.
|
94354f8a-a6b1-4bcd-944d-d631750cb5f6
| 3 |
Neither of the inhibitors affected cell viability. In the presence of inhibitors of degradation, binding sites for insulin with high affinity were detected, which by multiple criteria were true insulin receptors. Binding to these sites was rapid, saturable, and reversible with about 1000 sites/cell. The Hill coefficient for binding was 0.7
|
94354f8a-a6b1-4bcd-944d-d631750cb5f6
| 4 |
, and the Scatchard plot of B/F versus B was curvilinear, due to site-site interactions of the negative cooperative type; the latter were demonstrated directly by kinetic studies. As shown previously for all other insulin receptors, binding was highly pH-dependent, and insulin analogues had affinities for these sites that closely correlated with their biological potencies.
|
bee2fbf0-f1f3-48a2-b9ff-760d51455f4a
| 0 |
Triiodothyronine effects on some electrogenic properties of frog sartorius. At 21 degrees C in vitro, 0.2 and 2.0 muM of triiodothyronine (T3) produced an increase in resting membrane potential (RMP) of Rana pipens sartorius when the pH of the external solution was 7.4. The RMP was increased by 2.0
|
bee2fbf0-f1f3-48a2-b9ff-760d51455f4a
| 1 |
muM T3 in the presence of 10(-4) and 10(-3) M ouabain but not in 10(-3) M of 2,4 dinitrophenol. Small increases in RMP were observed with 2.0 muM T3 in solutions with low external Na. At pH 7.1 0.2 muM T3 produced a small transient increase in RMP.
|
bee2fbf0-f1f3-48a2-b9ff-760d51455f4a
| 2 |
Membrane resistance (Rm) was found to decline gradually during exposure to 0.2 muM at a pH of 7.4. Treatment with 2.0 muM T3 at pH 7.4 was accompanied by a transient reduction in Rm. Similar transient changes in Rm were produced by 0.2 and 2.0 muM T3 at pH of 7.1
|
bee2fbf0-f1f3-48a2-b9ff-760d51455f4a
| 3 |
T3 reduced membrane resistance in isotonic K2SO4 and tris-buffered Mn (20 mM) solutions indicating that T3 increases potassium permeability. Direct action potentials were studied at pH 7.1. Overshoot, amplitude and rate of rise of the action potential underwent a gradual decrease in the presence of 0.2 muM T3 while thresholds remained unchanged.
|
bee2fbf0-f1f3-48a2-b9ff-760d51455f4a
| 4 |
Thresholds were increased during exposure to 2.0 muM T3 whereas overshoot, amplitude and rate of rise underwent transient decreases followed by a return toward control levels.
|
64e5d854-84d2-47a9-983c-8e05fde92bdc
| 0 |
[Acute amebic abscess of the liver followed by colonic ulcers. Report of 2 cases]. Two unusual cases of ruptured acute amebic liver abcess are presented one with inferior vena caval compression. Surgical drainage was followed by the development of colonic complications (haemorrhage and perforation) although the patients were under specific therapy. After a new surgical operation both cases were cured. The relation with amebiasis is discussed. The possibility of such an association must always be kept in mind. The value of immunofluorescence test in the diagnosis is emphasised.
|
206229e2-00df-4126-8acf-c5ccd2bdef2e
| 0 |
High-performance ion-pair partition chromatography of sulfa drugs. Study and optimization of chemical parameters. High-performance ion-pair partition chromatography is shown to be a versatile, efficient method for separating sulfonamides. For a group of fourteen sulfa drugs varying widely in pKA and hydrophobicity, the effect of mobile phase composition, counterion composition, pH, and ionic strength on their ion-pair partition chromatographic separation using tetrabutylammonium as the counterion and n-butanol-n-heptane as the mobile phase is shown.
|
206229e2-00df-4126-8acf-c5ccd2bdef2e
| 1 |
Wide variation in k' and a is possible by changing these parameters. Silica columns coated with buffered aqueous solutions of tetrabutylammonium sulfate resulted in efficiencies of 4000-6000 theoretical plates per 25 cm. These columns are stable for long periods of time, and can be stripped and re-used in the adsorption mode with little or no loss in efficiency.
|
206229e2-00df-4126-8acf-c5ccd2bdef2e
| 2 |
Several chromatograms are presented in order to illustrate the performance of ion-pair partition chromatography.
|
d1cc3c8f-0f35-487e-811a-9932287bf4a6
| 0 |
Gas chromatographic determination of carboxylic acid chlorides and residual carboxylic acid precursors used in the production of some penicillins. An improved gas chromatographic method is described for the simultaneous determination of carboxylic acid chlorides and related carboxylic acids used in the production of some commercial semisynthetic penicillins. The acid chloride reacts with diethylamine to form the corresponding diethylamide.
|
d1cc3c8f-0f35-487e-811a-9932287bf4a6
| 1 |
Carboxylic acid impurities are converted to trimethylsilyl esters. The two derivatives are separated and quantitated in the same chromatographic run. This method, an extension of the earlier procedure of Hishta and Bomstein (1), has been applied to the acid chlorides used to make oxacillin, cloxacillin, dicloxacillin, and methicillin (Figure 1);
|
d1cc3c8f-0f35-487e-811a-9932287bf4a6
| 2 |
it shows promise of application to other acid chlorides. The determination is more selective than the usual titration methods, which do not differentiate among acids with similar pK's. Relative standard deviations of the acid chloride determination are 1.0-2.5%. Residual carboxylic acid can be repetitively determined within a range of 0.6
|
d1cc3c8f-0f35-487e-811a-9932287bf4a6
| 3 |
% absolute.
|
bc90e875-ba04-4705-8965-70138c284e68
| 0 |
Demonstration and some properties of cytosol-binding proteins for thyroxine and triiodothyronine in human liver. Cytosol-binding proteins for L-thyroxine (T4) and triiodo-L-thyronine (T3) were studied in human liver specimens obtained at autopsy from 5 male and 2 female subjects. The liver cytosol containing 131I-T4 or T3, together with or without added stable hormones, was fractionated by Pevikon thin-layer electrophoresis at pH 8.6
|
bc90e875-ba04-4705-8965-70138c284e68
| 1 |
, 8.0, and7.4. It was demonstrated in all the specimens that besides a small amount of serum T4-binding globulin, there existed three T4-binding proteins, termed hT4-1, hT4-2 and hT4-3, with the electrophoretic mobilities of alpha2- and beta-globulins, and two T3-binding proteins, termed hT3-1 and hT3-2, with the mobilities of gamma-globulin.
|
bc90e875-ba04-4705-8965-70138c284e68
| 2 |
Binding of hormones by the cytosol proteins was pH-dependent, and a preliminary dialysis had no effect on the hormone binding. The major band of T4, hT4-2, bound more than half the tracer T4, and possessed the maximal binding capacity of 110 mug/100 ml of 33% cytosol at pH 7.4
|
bc90e875-ba04-4705-8965-70138c284e68
| 3 |
. However, it showed no apparent affinity for T3, because the bound T4 could not be displaced with a T3 load of 600 mug/100 ml. The major band of T3, hT3-2, bound more than 70% of the tracer T3, and appeared to have a large capacity for the hormone although secondary binding sites on the same molecule might be responsible for the large capacity.
|
bc90e875-ba04-4705-8965-70138c284e68
| 4 |
The binding sites appeared almost specific for T3, because only a small, insignificant displacement was noted with a T4 load of 600 mug/100 ml. The results provide evidence for distinct binding proteins for T4 and T3 in the human liver cytosol, though their physiological roles remain to be elucidated.
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04289444-ebba-4cd0-9f12-f7543f408ea0
| 0 |
Glucagon-sensitive adenylate cyclase in human renal medulla. In cell-free preparations (washed 600 x g pellets) of human renal medulla, glucagon produced a dose-dependent stimulation of adenylate cyclase. The stimulation of renal medullary adenylate cyclase by saturating concentrations of glucagon was additive to the saturating doses of vasopressin.
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04289444-ebba-4cd0-9f12-f7543f408ea0
| 1 |
Furthermore, L-isoproterenol stimulated renal medullary adenylate cyclase in a dose-dependent manner, and this stimulation was blocked by DL-propranolol. Stimulation of the renal medullary adenylate cyclase by maximal doses of glucagon and L-isoproterenol was additive. DL-Propranolol did not inhibit stimulation of glucagon. Thus, the results indicate the existence of a specific adenylate cyclase that is responsive to glucagon--distinct from the isoproterenol-sensitive adenylate cyclase and the previously described vasopressin-sensitive adenylate cyclase in human renal medulla.
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04289444-ebba-4cd0-9f12-f7543f408ea0
| 2 |
We suggest that the renal tubular effect of glucagon may be mediated by glucagon-dependent cyclic-AMP production in renal tissue.
|
8dcbf096-7a1a-4493-bdd9-3c301fa1760a
| 0 |
Simultaneous comparison of delta 5-3beta-hydroxysteroid levels in the fetoplacental circulation of normal pregnancy in labor and not in labor. Concentrations of pregnenolone (delta5P), dehydroepiandrosterone (DHEA), 16alpha-hydroxydehydroepiandrosterone (16alpha-OH DHEA), pregnenolone sulfate (delta5P-S), and dehydroepiandrosterone sulfate (DHEA-S) were measured simultaneously by radioimmunoassay in individual, paired umbilical artery (UA) and vein (UV) sera from 18 normal term pregnancies, 6 in labor, 12 not in labor.
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8dcbf096-7a1a-4493-bdd9-3c301fa1760a
| 1 |
Mean UA and UV levels +/- SEM (ng/ml) were for delta5P: 30.39 +/- 1.69, 35.55 +/- 3.06; DHEA: 12.31 +/- 2.34, 3.66 +/- 0.38; 16alpha-OH DHEA: 7.48 +/- 0.63, 10.59 +/- 0.78; delta5P-S: 1,652 +/- 154, 1,486 +/- 130;
|
8dcbf096-7a1a-4493-bdd9-3c301fa1760a
| 2 |
DHEA-S: 2,122 +/- 134, +/- 134, 1,906 +/- 134. Umbilical artery delta5P-S, DHEA-S, and DHEA levels were significantly higher than UV levels, whereas the reverse was true for delta5P and 16alpha-OH DHEA. The inverse arterio-venous (A-V) gradient for 16alpha-OH DHEA was contrary to previous published reports using pooled samples.
|
8dcbf096-7a1a-4493-bdd9-3c301fa1760a
| 3 |
Comparison by linear regression of paired UA and UV steroid concentrations of delta5P, delta5P-S, DHEA, and DHEA-S revealed a significant correlation (P less than 0.01) for each steroid. Labor was associated with a significant increase in UA levels of DHEA-S and a smaller, but not quite significant, increase in UA levels of delta5P-S, while similar changes for unconjugated delta5-3beta-hydroxysteroids were not observed.
|
8dcbf096-7a1a-4493-bdd9-3c301fa1760a
| 4 |
Mean A-V gradients between the group of patients in labor and those not in labor were not significantly different. These data demonstrate that: 1) a significant difference between UA and UV concentrations exists for delta5P, DHEA, 16alpha-OH DHEA, delta5P-S, and DHEA-S; 2) there is a significant correlation between UA and UV concentrations for delta5P, DHEA, delta5P-S, and DHEA-S, implying that each fetoplacental unit maintains an equilibrium relative to these steroid concentrations in the umbilical circulation;
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8dcbf096-7a1a-4493-bdd9-3c301fa1760a
| 5 |
3) labor is associated with a significant increase in UA levels of DHEA-S and probably of delta5P-S.
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3f185f21-186d-4b73-ad07-618503d3ce5f
| 0 |
Isolation of human eosinophil phospholipase D. Phospholipase D preferentially contained in human eosinophil polymorphonuclear leukocytes as compared to other leukocytes was isolated by sequential asion and cation exchange chromatography and gel filtration. The purified eosinophil enzyme specifically liberated choline from I-alpha-phosphatidyl choline with a pH optimum of 4.5
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3f185f21-186d-4b73-ad07-618503d3ce5f
| 1 |
-6.0 and exhibited a pI of 5.8-6.2 on polyacrylamide-gel isoelectric focusing, which are properties shared by phospholipase D from plant sources; however, its apparent mol wt of 60,000 is approximately one-half that of the plant enzymes. Eosinophil and cabbage phospholipase D inactivated a partially purified rat platelet-activating factor (PAF) in a time- and dose-dependent reaction.
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3f185f21-186d-4b73-ad07-618503d3ce5f
| 2 |
The cleavage of this PAF activity was attributed to the inherent phospholipase D activity of the eosinophil enzyme since the two activities chromatographed together at each purification step, and there was apparent reciprocal inhibition of choline-generating activity by PAF and of PAF-inactivating activity by phosphatidyl choline. Thus, possible regulatory functions of the eosinophil in immediate hypersensitivity reactions include inactivation of a PAF by phospholipase D as well as degradation of slow-reacting substance of anaphylaxis by arylsulfatase B.
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70e87bc8-05d6-41ac-b19a-1e33be465a33
| 0 |
Role of expectancy set in the systematic desensitization of speech anxiety: an extension of prior research. The influence of expectancy set with regard to therapy outcome on the effectiveness of systematic desensitization (SD) for reducing public speaking anxiety was investigated. The 7 Ss given a high expectancy set for favorable therapy outcome were informed about psychological research that indicates that SD is effective to reduce public speaking fears.
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70e87bc8-05d6-41ac-b19a-1e33be465a33
| 1 |
SD was administered with the standard instructions to the 11 Ss given a neutral expectancy set. This expectancy manipulation did not require deception and perhaps could be used with actual SD therapy clients. As in previous research by Woy and Efran, the expectancy set manipulation significantly modified Ss' self-report of subjective perceptions of anxiety from pretreatment to posttreatment speeches, but did not affect overt behavioral or physiological indices of anxiety.
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70e87bc8-05d6-41ac-b19a-1e33be465a33
| 2 |
Since subjective perceptions of anxiety responses are psychologically significant behaviors, these data suggest the importance of conveying a high expectation of improvement to SD and perhaps also to other types of therapy clients. SD sessions administered to small groups of clients on consecutive days, as in this study, appeared to be as effective to reduce speech anxiety as SD sessions administered to each client individually at 1-week intervals, as in the Woy and Efran study.
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6bdb7fe1-3be2-4530-8fd7-7be3f7a9b9b6
| 0 |
Graduated approach modeling in an aversive task. Sixty female Ss were assigned randomly to six conditions that involved self-administration of electrical shock. These were: (1) no model-one trial S response; (2) no model-graduated trial S response; (3) one trial model-one trial S response;
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6bdb7fe1-3be2-4530-8fd7-7be3f7a9b9b6
| 1 |
(4) one trial model-graduated S response; (5) graduated model-one trial response; and (6) graduated model-graduated response. Results indicated that graduated exposure of S to an aversive stimuli was more effective than a single such exposure and that type of exposure provided by a model had little effect.
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1971ea45-ae76-4399-a530-8e7f06ef8364
| 0 |
Cephradine excretion in humans with pH-altered urine. In a random crossover study, ten healthy men were pretreated with ammonium chloride or sodium bicarbonate to alter urinary pH, and then were given a single 1-Gm dose of cephradine, either orally or intravenously. No significant changes were found in the terminal phase rate constant nor in the time or magnitude of peak concentration.
|
1971ea45-ae76-4399-a530-8e7f06ef8364
| 1 |
Total recovery was greater than 90 per cent whenever degradation of cephradine did not occur. An unexplained but significant reduction in area under curve was present in data for prealkalinized subjects and for all subjects who took cephradine orally. Trapping of cephradine was not significant in the excretory pathway.
|
63bda688-34fb-4747-90b5-f9b0d33d10a4
| 0 |
Partial agonist properties and toxicity of oral oxilorphan. Alternative pharmacologic adjuncts are needed for the management of opiate abuse. Oxilorphan, a narcotic antagonist, was studied at 5 different dose levels (1, 2, 4, 6, and 8 mg) in 30 normal subjects to determine the relation of single oral doses and toxicity.
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63bda688-34fb-4747-90b5-f9b0d33d10a4
| 1 |
The drug causes pupillary constriction and mild central nervous system side effects (nausea, dizziness) at all doses. Mean urine volume increased (P less than 0.05) during the 12 hours after 1 and 2 mg. Oxilorphan has partial agonist properties similar to dl-cyclazocine.
|
1f777429-b7eb-42a1-a162-25a1df851206
| 0 |
Characteristics of the release of adenosine 3':5'-monophosphate from micropipets by microiontophoresis. The transfer number for radio-labelled cyclic AMP released from microiontophoretic pipets into brain pieces was determined for a large number of samples by radioassay. Release of cyclic AMP was linearly related to both iontophoretic current intensity and time as predicted by Faraday's Law.
|
1f777429-b7eb-42a1-a162-25a1df851206
| 1 |
The results revealed that cyclic AMP has a rather low transfer number. In addition, an unusually large amount of variation of release, both within and among pipets was found under a variety of times and currents. The cause of the variation is not known but could be due to the unusual structure of the cyclic AMP molecule and the fact that it must be iontophoresed as a negative ion.
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1f777429-b7eb-42a1-a162-25a1df851206
| 2 |
These characteristics of cyclic AMP release may contribute to the difficulty in obtaining positive responses from appropriate neuronal target cells in vivo.
|
437db867-9162-4f10-ae7b-24d2ea120f39
| 0 |
Effects of egg factors on cyclic nucleotide metabolism in sea urchin sperm. Cyclic AMP in Strongylocentrotus purpuratus sperm was elevated approximately 2-fold by theophylline or 1-methyl-3-isobutylxanthine. Factors released from sea urchin eggs (FRE) elevated sperm cyclic AMP by about 7-fold within 1 min, and the combination of FRE with theophylline increased sperm cyclic AMP up to 100-fold within 1 min.
|
437db867-9162-4f10-ae7b-24d2ea120f39
| 1 |
Cyclic GMP in sea urchin sperm was slightly elevated by theophylline, but was lowered by FRE. Cyclic GMP in sperm treated with FRE plus theophylline was not higher than in sperm treated with theophylline alone. The ability of FRE-containing sea water to increase sperm cyclic AMP in the presence of theophylline was altered only slightly if at all by boiling, but it was decreased by about 50% by dialysis and destroyed by ashing.
|
437db867-9162-4f10-ae7b-24d2ea120f39
| 2 |
Filtration of FRE on Sephadex G-50 columns yielded two peaks of cyclic AMP-elevating activity. One peak (peak I) was eluted at the column void volume, and the other (peak II) was retained by the column. The cyclic GMP-lowering activity was located in fractions approximately corresponding to peak I of cyclic AMP-elevating activity.
|
437db867-9162-4f10-ae7b-24d2ea120f39
| 3 |
Dialysis of FRE-containing sea water before its application to the G-50 column virtually eliminated peak II of the cyclic AMP-elevating activity. When the cyclic AMP-elevating activity in peak I was filtered on Bio Gel A-5m columns, it also migrated at or near the column void volume.
|
437db867-9162-4f10-ae7b-24d2ea120f39
| 4 |
Fractions corresponding to peak I contained material that inhibited both guanylate and adenylate cyclase activities in broken cell preparations of sperm and guanylate cyclase from rat lung. The inhibitory material was stable to boiling, non-dialyzable, and destroyed by ashing. Under a variety of conditions, FRE-containing sea water or cyclic AMP-elevating peaks I or II did not stimulate sperm adenylate cyclase activity in broken cell preparations.
|
08a9426f-b8ff-4a6b-af89-bccf0d0683f8
| 0 |
Dephosphorylation of bovine casein by milk alkaline phosphatase. The pH of optimum activity of alkaline phosphatase from cow's milk depended on the substrate, being 10-1 for rho-nitrophenylphosphate, 8-6 for phosphoserine, 8-0 for phosvitin and 6-8 for casein. Individual casein components were dephosphorylated more rapidly than mixtures of alphas- and beta-caseins or of alphas-, beta-and kappa-caseins and micellar casein.
|
08a9426f-b8ff-4a6b-af89-bccf0d0683f8
| 1 |
Mixtures of 2 components involving kappa-casein were more readily dephosphorylated than alphas- and beta-casein mixtures. At pH 6-8, lactose, whey proteins and phosphate ions had an inhibitory effect. beta-Lactoglobulin had an inhibitory effect only when the pH of the reaction was lower than the optimum pH value of the enzyme.
|
08a9426f-b8ff-4a6b-af89-bccf0d0683f8
| 2 |
Mg2+ and Zn2+ were not inhibitory. The optimum conditions for dephosphorylation of casein are described.
|
131ee9b9-0703-4b65-b59a-28740849adba
| 0 |
Effect of flurazepam on common clinical laboratory tests. Twenty-two clinical laboratory tests performed on blood samples from 16 normal subjects following one week of either flurazepam or placebo administered in a double-blind method showed no apparent chemical interference by flurazepam on any of the testing procedures.
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56e3a3af-f254-466a-b005-799c0e4cebc5
| 0 |
A kinetic concepto of lipid transport in ruminants. Summarization of the literature shows a strong correlation between dietary fatty acid intake and total lipid concentration in plasma in lactating cows whereas total milk fat secreted is related to neither of these. In the process of plasma triglyceride removal, chylomicra and very low density lipoproteins are converted to low density lipoproteins.
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56e3a3af-f254-466a-b005-799c0e4cebc5
| 1 |
Limited kinetic data indicate that the fractional removal rates for chulomicra and very low density lipoproteins are rapid in lactating cows whereas fractional removal of low density lipoproteins is slower, resulting in accumulation of the latter in plasma. Under such conditions, low density lipoprotein concentrations of plasma would not be expected to reflect quantitatively the transfer of plasma triglyceride fatty acids to milk fat.
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56e3a3af-f254-466a-b005-799c0e4cebc5
| 2 |
Quantitative analysis or triglyceride fatty acid turnover in density less than 1.006 lipoproteins should delineate the role of plasma lipid transport in milk fat synthesis. High fat diets protected from rumen biohydrogenation have proven to be a useful approach in studying ruminant fat metabolism and may be used more extensively to elucidate the role of cholesterol in plasma lipid transport and the metabolism of essential fatty acids in ruminants.
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1f084d9e-2afb-4ef8-9deb-6b24ff65029b
| 0 |
Bovine pancreatic lipase.I.Isolation, homogeneity, and characterization. Bovine pancreatic lipase was isolated in pure form by lyophilization of fresh bovine pancreas, extraction of the enzyme with sucrose solution, fractional precipitation with ammonium sulfate and acetone, followed by chromatography on Sephadex G-100. The specific activity of the purest lipase fraction was 1750 micromoles fatty acid, liberated in 30 min per milligram of protein, indicating a purification of approximately 473-fold, with an overall yield of about 42%.
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1f084d9e-2afb-4ef8-9deb-6b24ff65029b
| 1 |
Homogeneity of the enzyme was confirmed by rechromatography on Sephadex G-100 as well as with the gel electrophoretic and ultracentrifugal techniques. The purified enzyme gave a typical protein ultraviolet absorption spectrum with maximum absorption at 276 nm and minimum at 252 nm. The purified enzyme exhibited a single pH optimum of 8.8
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1f084d9e-2afb-4ef8-9deb-6b24ff65029b
| 2 |
and an isoelectric point near pH 5.5. Its optimum temperature was 37 C, and its optimum substrate concentration was 10%. These properties resembled those of milk lipase.
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7dae49f8-27e0-44db-8cb5-2117f9e1eb5a
| 0 |
Distribution and removal of cadmium from milk. Distribution of added cadmium in milk systems and the feasibility of removing cadmium were investigated. In milk containing 1 ppm cadmium, 96% of the added cadmium chloride was dispersed in the skim milk fraction, and 3% was associated with the cream fraction.
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7dae49f8-27e0-44db-8cb5-2117f9e1eb5a
| 1 |
Cadmium was not bound strongly to any protein fraction. The association of cadmium with acid casein, whey proteins, and the fat globule membrane was 18,6, and .5% of total added cadmium. With a 5-min exposure thiosuccinylated amino-ethyl cellulose, thionitrocarboxyphenylated aminoethyl cellulose, and reduced human hair removed 72, 70, and 30%, respectively, of added cadmium in skim milk previously equilibrated for 2 h at 37 C.
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7dae49f8-27e0-44db-8cb5-2117f9e1eb5a
| 2 |
Increasing equilibration time beyond 24 h had no effect on removal efficiency whereas increasing pH decreased cadmium removal markedly.
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af02135c-9282-4096-a57d-21644608ee74
| 0 |
Influence of viable yogurt microflora on digestion of lactose by the rat. Laboratory rats were fed experimental diets including yogurt, pasteurized yogurt, and simulated yogurt with sucrose or lactose for 7 days followed by a single experimental meal of yogurt, pasteurized yogurt, or simulated yogurt. Assays of blood galactose demonstrated that animals fed natural yogurt containing the viable culture microflora were able to absorb galactose more efficiently.
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af02135c-9282-4096-a57d-21644608ee74
| 1 |
Intestinal lactase activity of yogurt-fed animals was greater than in animals fed other experimental diets including pasteurized yogurt. Gastrointestinal survival of culture organisms was demonstrated in vivo up to 3 h after feeding, and thus, the viable cells resulted in more efficient hydrolysis which favored lactose digestion in natural yogurt.
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3f218d7e-4669-4b5a-ab7c-28de7a5b9fdd
| 0 |
Nonimmunologic aspects of caries resistance. A variety of components provide salivary secretions with an array of potentially effective means of combating cariogenic challenges. These defense factors range from a laissez-faire mechanical cleansing to exquisitely controlled production of highly specific antibodies. In between the two extremes are antibacterial systems whose operating characteristics are only beginning to be understood. These systems are well worth our attention. They may be the key to our understanding of variations in individual susceptibility, and could provide valuable leads for development of anticaries agents.
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26f2a7c3-3126-4947-9223-e32ba32ba8ca
| 0 |
Adherence of serotype e Streptococcus mutans and the inhibitory effect of Lancefield group E and S mutans type e antiserum. S mutans strain MT703 from an active carious lesion in the tooth of a child had type e specificity and showed a cross-reaction with the Lancefield group E cell wall streptococcal polysaccharide antigen.
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26f2a7c3-3126-4947-9223-e32ba32ba8ca
| 1 |
Heat-killed cells MT703 adhered to a glass surface in the presence of CGT MT703 and sucrose. Pretreatment of the cells with anti-MT703 whole cell serums inhibited adherecne. The removal of glycerol teichoic acid antibody and group E antibody from the MT703 serum did not result in a loss of inhibitory activity.
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26f2a7c3-3126-4947-9223-e32ba32ba8ca
| 2 |
Antiserum with or without adsorption significantly inhibited glucan synthesis by CGT from sucrose. Antibodies specific for the polyglycerol phosphate of teichoic acid did not inhibit adherence. Anti-group E serum and serums specific for other types of S mutans, did not show adherence inhibitory activity except for an occasional type c specific antiserum.
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26f2a7c3-3126-4947-9223-e32ba32ba8ca
| 3 |
Antibody specific for the type e antigen produced significant inhibition of the binding of CGT to the MT703 cell wall, and adherence of these cells did not occur. Antibody to CGT inhibited glucan synthesis. Treatment of the cells with dextranase, dextran antibody, or trypsin caused a significant reduction in adherence.
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26f2a7c3-3126-4947-9223-e32ba32ba8ca
| 4 |
The results suggest that the type antigen and dextran on the surface of the S mutans type e cell are functional in adherence, and that these polymers are associated with cell wall protein.
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5cd53020-eed4-45aa-a675-3fd7415021cd
| 0 |
The effect of beta adrenergic blockade on bronchial sensitivity to acetyl-beta-methacholine in normal and allergic rhinitis subjects. The effect of propranolol inhalation on sensitivity to methacholine inhalation was studied in normal and allergic rhinitis subjects to determine whether beta adrenergic blockade alters sensitivity to mediators in nonasthmatic atopic individuals. A partial beta adrenergic blockade is suggested as being instrumental in asthma. Hay fever patients studied showed similar effects and also developed asthma for the first time.
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5160d8f7-561e-4773-b9d1-8ce8dcdcaacd
| 0 |
Effect of beta adrenergic stimulation and blockade on cutaneous reactivity to histamine. It has been previously demonstrated that iontophoresis of beta adrenergic agents will alter the size of immediate hypersensitivity skin tests. It was unclear whether this alteration was due to an effect on the dermal mast cell (inhibition of histamine release) or on the cutaneous vasculature (inhibition of capillary permeability).
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5160d8f7-561e-4773-b9d1-8ce8dcdcaacd
| 1 |
For this reason isoproterenol, propranolol, diphenhydramine as a positive control, and saline as a negative control were iontophoresed onto the forearm of 10 atopic and 10 nonatopic adult subjects. In order to bypass histamine release from mast cells the patients were then challenged directly with histamine by the "prick" technique.
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5160d8f7-561e-4773-b9d1-8ce8dcdcaacd
| 2 |
The size of the resultant wheals was noted. The data obtained allowed the following conclusions: (1) The atopic group responded to histamine with greater wheal size than the nonatopic group. (2) Iontophoresis of diphyenhydramine effectively reduced the magnitude of the histamine wheal in both groups. (3) Isoproterenol decreased the wheal size in both groups.
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5160d8f7-561e-4773-b9d1-8ce8dcdcaacd
| 3 |
(4) Propranolol increased the wheal size in only the nonatopic group. (5) The successful modulation of the histamine-induced wheal and flare indicated that these drugs, regardless of their effect on the dermal mast cell, exert a measurable effect on the target organ (vasculature).
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1ed041e8-9e64-4b36-9941-abc519a69018
| 0 |
Further observations on the potentiation of the antibacterial effect of methenamine by acetohydroxamic acid. The use of methenamine in the treatment of urinary tract infections due to Proteus species is limited by urine alkalinity. Acetohydroxamic acid, an inhibitor of urease, maintains acidity despite growth of Proteus in urine. Easily achievable concentrations of acetohydroxamic acid in vitro systems that simulated the dynamics of the urinary tract potentiated the antibacterial effect of methenamine against Proteus species. The combined use of a urease inhibitor and methenamine may be effective in the treatment of urinary infection caused by these organisms.
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e8247419-3be5-43ed-9726-b04be57e2f5e
| 0 |
Hematopoietic thymocyte precursors. I. Assay and kinetics of the appearance of progeny. A quantitative assay for the hematopoietic precursor of thymocytes has been developed. Using this assay the kinetics of appearance of the progeny of transfused bone marrow and spleen cells in the thymus of irradiated (760 R) mice has been studied.
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e8247419-3be5-43ed-9726-b04be57e2f5e
| 1 |
Precursor cells are seven to eightfold more common in bone marrow than in spleen and are absent from peripheral lymph nodes. They decline in number as the animals age. When hematopoietic cells are injected immediately after lethal irradiation only a small number of cells actually enter the gland. Their progeny are not detectable in the thymus for 8-12 days.
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e8247419-3be5-43ed-9726-b04be57e2f5e
| 2 |
The time of their detection depends both upon the size of the residual endogenous thymocyte population and the number of progenitor cells injected. Evidence has been presented that excludes thymic injury as the basis for the delay in the appearance of donor type cells and indicates that neither the production of a "homing" signal in the irradiated animal nor the development of precursor cells are limiting factors in the rate of thymic repopulation.
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e8247419-3be5-43ed-9726-b04be57e2f5e
| 3 |
These studies indicate that only an exceedingly small number (less than 100) of prothymocytes are required to repopulate the thymus of an irradiated mouse. This restricted number of progenitors must produce the entire repertory of T-cell immunologic responsiveness seen in the first weeks after repopulation.
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