bluuebunny/crossref_metadata_2025_split huggingface dataset:
Some effects of caffeine and aminophylline on the turnover of catecholamines in the brain
Authors: WALDECK BERTIL 
Published: April 2011

Abstract
The effect of caffeine and aminophylline on the turnover of noradrenaline and dopamine in the mouse brain was studied by two different methods: estimation of the rate of disappearance of the transmitter after inhibition of synthesis and measurement of the accumulation of [3H]noradrenaline (3H-NA) and [3H]dopamine (3H-DA) after administration of [3H]tyrosine. After inhibition of the tyrosine hydroxylase the xanthines had little or no effect on the disappearance of both catecholamines. After inhibition of dopamine β-hydroxylase, both xanthines increased the rate of disappearance of noradrenaline. When given in sufficiently large doses both xanthines increased the yield of 3H-NA and 3H-DA from [3H]tyrosine. Pretreatment with a monoamine oxidase inhibitor caused a decrease in the yield of the tritiated catecholamines, which could be counteracted by the xanthines. Stimulation of the noradrenaline receptors by clonidine appeared to cause a decrease in the yield of 3H-NA and an increase in the amount of 3H-DA formed from [3H]tyrosine. Conversely, stimulation of the dopamine receptors by apomorphine caused a decrease in the yield of 3H-DA and an increase in that of 3H-NA. Also, in caffeine-treated animals, clonidine and apomorphine decreased the yield of 3H-NA and 3H-DA respectively. However clonidine could not increase 3H-DA concentrations, nor apomorphine the 3H-NA concentrations more than did caffeine alone. Thus, caffeine and aminophylline appear to increase the rate of turnover of both catecholamines in the brain.
Structural influences upon antihistamine activity; 3-amino-1-aryl-1-(2-pyridyl)propenes and related compounds
Authors: ISON R R , CASY A F 
Published: April 2011

Abstract
A series of 3-amino-1-aryl-1-(2-pyridyl)propenes and related compounds have been prepared by the dehydration of corresponding tertiary alcohols, and the configurations of geometrical isomeric derivatives established from spectroscopic data. The ability of the aminopropenes to antagonize histamine-induced contractions of the guinea-pig ileum is reported. These data allow various structure-activity relations to be discussed including stereochemistry (cis 2-pyridyl/H geometry is superior to cis substituted phenyl/H but not necessarily to cis phenyl/H), nature of the basic function (1-pyrrolidino is markedly superior to either dimethylamino or 1-piperidino) and the importance of the vinylic hydrogen atom (sharp falls in potency follow its replacement by methyl).
Potential irreversible inhibitors of acetylcholinesterase: N-trimethyl-N‘-iodoacetyl diaminoalkane iodides
Authors: BEDDOE F , NICHOLLS P J , SMITH H J 
Published: April 2011

Abstract
Potential irreversible inhibitors of acetylcholinesterase based on N-trimethyl-N'-iodacetyl diaminoalkane iodide Me3N+[CH2]n-NHCO·CH2I·I-, (I; n = 4) and (II; n = 2) have been prepared. (I) and (II) are both competitive inhibitors of the enzyme with Ki, 5·9 times 10−4m and 1·2 times 10−3m respectively. (I) is a partial agonist and (II) is a true agonist at the muscarinic receptor of guinea-pig ileum.
Sulphamethoxydiazine crystal forms
Authors: MOUSTAFA M A , EBIAN A R , KHALIL SAID A , MOTAWI M M 
Published: April 2011

Abstract
Methods of preparation of three polymorphs, two solvates and an amorphous modification of sulphamethoxydiazine are described. Infrared spectroscopy and X-ray diffraction data are given for the characterization of the various forms. The interconversion of these forms under various conditions of heating, suspension in water and grinding is studied. The dissolution behaviour of the different forms is also discussed. All forms on heating to 150° change to the same form and on suspension in water change to another water-stable form.
A rapid method for the determination of salicylate binding by the use of ultrafilters
Authors: SPECTOR REYNOLD , KORKIN DENISE T , LORENZO A V 
Published: April 2011

Abstract
An ultrafiltration method that combines speed, simplicity, accuracy and precision was employed to measure plasma binding of salicylate. Human plasma, containing 1·0 and 0·1mm sodium salicylate, was ultrafiltered through membranes using 45 p.s.i. and slow rotational stirring. Salicylate was bound at these concentrations 13·1 and 4·4% respectively. This method, using membranes that quantitatively separate small molecules from plasma proteins, yields results comparable to those obtained by equilibrium dialysis.
Inotropic effects of atropine on ureteral muscle
Authors: CUTHBERT A W , ŠEFERNA I 
Published: April 2011

Abstract
Atropine (1–10 μg ml) produced an inotropic effect in the smooth muscle of the guinea-pig isolated ureter. This appeared to be caused by an increase in the safety factor for conduction in this muscle. Whether the effect of atropine is exerted directly on the muscle fibres or via intramural nerves is discussed.
Detection and identification of trace steroids in prednisolone
Authors: COMPERNOLLE F , VANDERHAEGHE H , NONCLERCQ M 
Published: April 2011

Abstract
Prednisolone samples from different commercial sources produced during 1965–1970 were examined by thin-layer chromatography on silica gel in the system chloroform-methanol-water (180:15:1). When large quantities were applied on the plates several trace compounds were detected. These were eluted from the silica gel and identified by mass spectrometry. The presence of 20-dihydro- prednisolone, hydrocortisone, prednisone, 11-desoxyprednisolone, 21-desoxyprednisolone, and prednisolone 21-acetate was detected. The Δ5-isomer of prednisolone was also found, but this product probably is an artifact formed during the isolation procedure. The different impurities also could be detected in prednisolone after chromatography in the system dichloromethane-dioxan-water (2:1:1). Impurities found in the British Chemical Reference Standard Prednisolone were hydrocortisone (very weak), prednisone and an unidentified product present at the start.
Metabolism of amphetamines. Identification of N-oxygenated products by gas chromatography and mass spectrometry
Authors: Beckett A H , Coutts R T , Ogunbona F A 
Published: April 2011

Abstract
A sensitive method for the isolation and identification of N-oxygenated metabolites and metabonates of medicinal amines is described. A combination of gas chromatography and mass spectrometry is effective in separating and identifying secondary hydroxylamines, oximes and nitrones, all of which are N-oxygenated products of secondary amines. These products give mass spectra containing diagnostic fragment ions which are of great value in identification. Primary hydroxylamines are oxidized on column to oximes and can be separated and identified as such. This oxidation is avoided if the primary hydroxylamine is introduced by direct inlet into the mass spectrometer. Secondary hydroxylamines are more stable during gas chromatographic examination although some decomposition to nitrone and secondary amine does occur. In contrast, oximes and nitrones show no tendency to decompose when gas chromatographed.
The action of vasoactive drugs on longitudinal and circular muscle of dog mesenteric vein
Authors: Hall W J , O'Connor P C 
Published: April 2011

Abstract
The dog anterior mesenteric vein has outer longitudinal and inner circular muscle layers. The response of the vein to drugs was recorded without disrupting the muscle arrangements by combining constant-flow perfusion of a segment with isometric recording of longitudinal tension. Noradrenaline and acetylcholine were potent stimulants. Tachyphylaxis developed to histamine, 5-hydroxytryptamine and angiotensin. Cocaine and guanethidine potentiated the responses to noradrenaline and fluorescent microscopy confirmed the presence of adrenergic nerves in both muscle layers. Isoprenaline partially relaxed the stimulated vein and this action was blocked by propranolol. Evidence was obtained which suggests the existence in the vein of specific receptors for several of the agonists investigated.
The effect of submaximal doses of pentagastrin on gastric acid secretion, histamine and histidine decarboxylase in rats
Authors: Weidle E , Sewing K-FR 
Published: April 2011

Abstract
In Lai-rats gastric mucosal histamine and histidine decarboxylase were estimated after stimulation of gastric acid secretion by intravenous infusions of submaximal doses of pentagastrin for 1 or 2 h. Pentagastrin produced a dose-dependent acid response with a maximum of 26 μ equiv H+ per 10 min at a dose of 2.56 μg kg−1 min−1. There was a linear relation between the log dose of pentagastrin and the activation of gastric histidine decarboxylase. The highest dose of pentagastrin yielded a histidine decarboxylase activity of 200% of the unstimulated level when infused for 1 h and of 290% when infused for 2 h. No reduction of gastric mucosal histamine could be detected whatever the dose of pentagastrin or the duration of infusion. It was concluded (1) that stimulation of gastric histidine decarboxylase is a physiological function of gastrin-like peptides, (2) that a reduction of gastric mucosal histamine by gastrin or pentagastrin is a pharmacological rather than a physiological effect, and (3) that no negative feedback relation exists beween gastric mucosal histamine and the activation of histidine decarboxylase.
Oscillatory testing of o/w emulsions containing mixed emulsifiers of the surfactant-long chain alcohol type: self-bodying action
Authors: Barry B W , Eccleston G M 
Published: April 2011

Abstract
Liquid paraffin-in-water emulsions stabilized by cationic (cetrimide) or non-ionic (cetomacrogol) surfactants and cetostearyl alcohol were examined at 25° in oscillatory mode, using the Weissenberg Rheogoniometer with parallel plates coupled to a digital transfer function analyser. Ternary systems, formed by dispersing the mixed emulsifiers in water, were similarly investigated. Each preparation was tested in the linear viscoelastic region, and fundamental rheological parameters, the storage modulus (G') and the real viscosity (ẽ') were derived as functions of frequency over the range 7.91 times 10−4to 25 Hz. All ternary systems behaved similarly with respect to frequency. As this increased, G' rose and ẽ' fell. These trends were related to the viscoelastic nature of the systems. Both mixed emulsifiers exhibited self-bodying mechanisms, so that emulsion consistency increased as the mixed emulsifier concentration rose. This was shown by increases in G' and ẽ' at each frequency. The shapes of the plots and other rheological properties were related to viscoelastic gel networks formed in the emulsion continuous phases. The ternary system parameters implied that emulsion networks were similar to ternary gels, that is, they formed by the interaction of long chain alcohol and aqueous surfactant solution. The oscillatory data were compared and correlated with creep data derived for similar ionic and non-ionic dispersed systems, previously described.
An analysis of the inter-subject variation in the metabolism of pentazocine
Authors: Vaughan D P , Beckett A H 
Published: April 2011

Abstract
Significant inter-subject variation in the cumulative urinary excretion of pentazocine, following its oral administration, was observed. Individual variations in the rate of metabolic oxidation of pentazocine are responsible for the variations in the urinary excretion of pentazocine (24 h cumulative). Smoking did not affect the metabolism of the drug. Pharmacokinetic analysis of the urinary excretion rate of pentazocine, using an open three compartment model, indicated that the fractional metabolic clearance is correlated with the cumulative urinary excretion (24 h) of the drug under conditions of acidic urinary pH. A g.l.c. method for the determination of pentazocine in urine is described.
The actions of some anticholinesterase drugs on skeletal muscle in culture
Authors: Harvey A L , Dryden W F 
Published: April 2011

Abstract
The actions of the anticholinesterase drugs, physostigmine, neostigmine and diisopropylfluorophosphate (DFP) on chick embryonic skeletal muscle in culture were studied. None of the anticholinesterases potentiated depolarization responses to acetylcholine. In high concentrations neostigmine and physostigmine produced depolarization. The neostigmine-induced, but not the physostigmine-induced, depolarization was antagonized by tubocurarine. DFP caused an increase in the rate of repolarization during the presence of a cholinomimetic. It is concluded that the cholinesterase present in cultured muscle fibres does not have a physiological role in hydrolysing acetylcholine and that physostigmine and DFP have an action at the ionic channels that are linked to the cholinoreceptor.
Gas-liquid chromatographic estimation of lignocaine, ethylglycylxylidide, glycylxylidide and 4-hydroxyxylidine in plasma and urine
Authors: Adjepon-Yamoah K K , Prescott L F 
Published: April 2011

Abstract
Gas-liquid chromatographic methods have been developed for the estimation of lignocaine and its metabolites ethylglycylxylidide (EGX), glycylxylidide (GX) and 4-hydroxyxylidine in plasma and urine. Lignocaine, EGX and GX were extracted from alkaline solution, the metabolites were acetylated and the three compounds were chromatographed simultaneously using single column temperature programming with a nitrogen-sensitive flame ionization detector. The limits of detection were 10–30 ng ml−1. Conjugated 4-hydroxyxylidine in urine was hydrolysed with glusulase and chromatographed as the acetyl derivative.
Compression characteristics of powders: radial die wall pressure transmission and density changes
Authors: Carless J E , Leigh S 
Published: April 2011

Abstract
An instrumented single punch tablet machine was used to study the relations between axial pressure, radial die wall pressure and density changes in beds of powder undergoing compression. Aspirin, sodium chloride, paracetamol, paracetamol-polyvinylpyrrolidone and sucrose crystals were examined. The development and transmission of radial pressure during loading and unloading of the bed is discussed in relation to yield and elastic behaviour of the powder. The relation between mean stress and relative density of the compact is explained on the basis of plastic flow and/or crushing of the particles. Differences in stress vs density relations due to difference in particle size of sucrose were due to initial packing conditions in the die and not to differences in pressure transmission.
The fate of intravenous [3H]glycopyrrolate in man
Authors: Kaltiala Eero , Penttilä Aneri , Vapaatalo Heikki , Larmi Teuvo 
Published: April 2011

Abstract
Glycopyrrolate was labelled in one methyl group with tritium and its fate was studied in six patients with T-tube drainage by determining serum levels as well as the biliary and urinary excretion of radioactivity after intravenous injection. More than 90 % of the radioactivity had disappeared from serum in 5 min and after 30 min almost no radioactivity could be found. The highest radioactivity in bile was found in samples taken 30 or 60 min after the injection. However, measurable radioactivity was found in most cases after 48 h. The first urine samples (0–3 h) showed the greatest radioactivity, and in 48 h 85% of the total radioactivity was excreted into the urine. Paper chromatography showed that both in bile and in urine over 80% of the radioactivity corresponded to unchanged glycopyrrolate. That appreciable amounts of glycopyrrolate were excreted into the bile suggests that the spasmolysis achieved with glycopyrrolate could be based partly on a local action on the bile ducts.
A Polarographie method for the determination of the N-oxide, N-oxide-sulphoxide and sulphoxide metabolites of chlorpromazine
Authors: Beckett A H , Essien E E , Smyth W Franklin 
Published: April 2011

Abstract
Cathode ray polarography has been used to measure chlorpromazine-N-oxide, N-oxide sulphoxide and chlorpromazine sulphoxide in mixtures. The response was linear when the metabolites were present in the range 10−5 to 5 times 10−8m in aqueous solutions. Reductive polarography of the mixed oxides in solution gave an additive wave from which individual oxides were determined by subtraction. Ultraviolet and Potentiometrie titration methods were used to determine the pKa values of the oxide metabolites of chlorpromazine. The mechanism of the reduction process was investigated using d.c. polarography and preparative micro-electrolysis. Polarographic analysis was applied to the determination of the metabolites after their separation from urine, plasma and microsomal preparations.
A quantitative gas-liquid chromatographic method for phorbol and related diterpenes as their acetates
Authors: Kinghorn A D , Evans F J 
Published: April 2011

Abstract
A qualitative and quantitative gas-liquid chromatographic technique has been described for the acetates of the parent alcohols of several irritant and co-carcinogenic factors of the genera Croton and Euphorbia. Four columns have been found to be useful for the identification of the acetates of phorbol, 4-deoxy-4α-phorbol, 12-deoxy-phorbol, ingenol and crotophorbolone. A mixed SE-30, E.G.S. column was used for quantitative analysis using codeine as internal standard. Percentage standard errors of the estimated relative weight ratios of diterpenes to codeine varied from 0·9 to 1·27% for between 21 and 42 estimations. With plant latex samples the total recoveries of added ingenol were 98·3 ± 3%. The method has been used to evaluate the latex of E. lathyris, E. millii, E. desmondi, E. triangularis and E. tirucalli. The same samples were also assayed by an irritancy biological assay developed by Hecker.
The cannabinoid content of Cannabis sativa L grown in England
Authors: Fairbairn J W , Liebmann J A 
Published: April 2011

Abstract
Twelve varieties of Cannabis sativa were grown out-of-doors in southern England during 1971 to 1973. Results show that for certain varieties highly active herbal cannabis can be produced. A warm climate with abundant sunshine does not therefore seem to be essential for high THC content. This was supported by results of growing plants in a greenhouse in varying lighting conditions including a limited period in total darkness. Considerable within and between plant variation was found and the importance of defining the plant part used, the stage of growth and the size of the sample is emphasized for comparative work involving quantitative results. Comparison of the present results with those for the same cannabis varieties grown in different parts of the world shows that all exhibit the same qualitative picture, that is, either THC-rich or CBD-rich. Since this chemical composition seems independent of environmental conditions it is inappropriate to refer to the two types as phenotypes; it is more likely that they represent two chemical races within the species Cannabis sativa L.
Competitive inhibition of Asp1-β-amide-Val5-angiotensin II by Sar1-Ile5-Ile8-angiotensin II in cat isolated cardiac muscle and coronary vessels
Authors: Türker R K , Hall M M , Bumpus F M 
Published: April 2011

Abstract
Interaction of Asp1-β-amide-Val5-angiotensin II with the 8-substituted analogue of Asp1-Ile5-angiotensin II, Sar1-Ile5-Ile8-angiotensin II, has been examined on the isolated perfused heart and isolated papillary muscle of the cat. The constrictor effect of angiotensin in the coronary vessels as well as its positive inotropic effect in the heart muscle have been shown to be competitively inhibited by Sar1-Ile5-Ile8-angiotensin II. The antagonistic potency and the duration of the antagonistic effect of the analogue in both coronary vessels and myocardium have been evaluated separately. The analogue has a higher antagonistic potency in coronary vessels than in heart muscle. The duration of the antagonistic effect of Sar1-Ile5-Ile8-angiotensin II was found to be longer in the heart muscle than in coronary vesesels. The possible mechanism of the antagonistic effect of Sar1-Ile5-Ile8-angiotensin II against Asp1-β-amide-Va15-angiotensin II is discussed.
A note on the interaction between two phosphated surfactants
Authors: Groves M J , Mustafa R M A , Carless J E 
Published: April 2011

Abstract
Evidence of an interaction between the water-soluble phosphated nonylphenolethoxylate (PNE) and the oil-soluble phosphated fatty alcohol ethoxylate (PFE) could not be obtained when the two compounds were mixed in the anhydrous state. However, measurements of refractive index, interfacial tension, density and viscosity of aqueous solutions of the two surfactants showed anomalies which were at a maximum when they were present in an approximately equal ratio by weight.
Thin-layer chromatography confirmed the anomalous properties of mixtures of the two compounds and it is suggested that these result from the formation of a complex material involving PNE, PFE and water.
On the pharmacology of Org 6368 (2β, 16β - dipiperidino - 5α - androstan - 3α - ol acetate dimethobromide), a new steroidal neuromuscular blocking agent
Authors: Sugrue M F , Duff N , McIndewar I 
Published: April 2011

Abstract
Org 6368 is a homologue of pancuronium bromide. Its interactions with other agents in the cat sciatic nerve-gastrocnemius muscle preparation revealed that paralysis was of the non-depolarizing type. This was confirmed in experiments using avian muscle. Org 6368 is a potent muscle relaxant being 2·4 times as potent as (+)-tubocurarine in the cat. Paralysis in the cat is rapid in onset and of appreciably shorter duration than that of pancuronium and (+)-tubocurarine. Repeated injections of the same dose of Org 6368 show no cumulative effect. Muscle relaxant doses generally cause a slight increase in both blood pressure and heart rate. Although its histamine-releasing capacity is greater than that of pancuronium it is less than that of (+)-tubocurarine. Org 6368 shares with pancuronium a very weak effect on both the muscarinic receptor and ganglionic transmission. Differences in the muscle relaxant profiles of Org 6368 and pancuronium are discussed.
Effects of a human plasma fraction on the release of chemotactic factors and anaphylatoxin from complement
Authors: Walker J R , Badcock J K , Ford-Hutchinson A W , Smith M J H , Billimoria F J 
Published: April 2011

Abstract
A fraction prepared from normal human plasma inhibits the release of chemotactic factors and anaphylatoxin when complement is activated by the alternate but not by the classical pathway. The fraction gave no interference with the actions of the released substances on either leucocytes or guinea-pig isolated ileum. The possible relation of this effect to the mechanism of the anti-inflammatory actions of the plasma fraction is discussed.
Surface tension and cloud point changes of polyoxyethylenic non-ionic surfactants during autoxidation
Authors: Donbrow M , Hamburger R , Azaz E 
Published: April 2011

Abstract
Changes in the surface tension-concentration curves of the non-ionic surfactant cetomacrogol, a polyoxyethylenic (POE) hexadecyl ether containing about 24 ethylene oxide (EO) groups, have been examined during autoxidation of aqueous solutions. The curves exhibit decreases in cmc values and changes in the slopes below and above the cmc which lead to the loss of the sharp break characteristic of micelle-formation. There is also a progressive decrease in the cloud point during autoxidation. Surface tensions and cloud points of a series of known POE hexadecyl ethers containing from 10 to 60 EO units have been measured and related to the number of EO units present. From these data, it is apparent that autoxidation of cetomacrogol is accompanied by degradation of the POE chain rather than the hydrocarbon chain, the number of EO units lost up to the time at which the solution becomes turbid being about 14. The significance of such measurements is discussed in relation to the detection of decomposition and pending rapid decomposition in synthesized and commercial surfactants.