bluuebunny/crossref_metadata_2025_split huggingface dataset:
A quantitative chromatographic method for the determination of purity of oxytetracycline
Authors: Bailey F 
Published: April 2011

Abstract
A chromatographic method for the determination of oxytetracycline is described, employing a hexane-ethyl acetate-pH 3·3 buffer partition system supported on Celite. Chromatographic separation is followed by measuring the absorbance of the eluate at 263 nm. The system enables the determination of oxytetracycline to be made in the presence of anhydro-oxytetracycline, chlortetracycline, α- and β-apo-oxytetracycline, and epi-oxytetracycline, the last three being the most likely contaminants of crude material.
The use of a thermoelectric osmometer to measure the osmotic coefficients of aqueous solutions of sodium salicylate at 25°
Authors: Deshmukh A , Fleming R 
Published: April 2011

Abstract
The use of a thermoelectric osmometer to measure osmotic coefficients for the binary system water-sodium salicylate at low concentrations (0·0 to 0·3 molal) is described. The accuracy and reproducibility of the instrument have been enhanced by employing a microscope to measure sample and reference drop sizes. Activity coefficients, calculated from the osmotic coefficients obtained in these experiments, have been combined with density and diffusional measurements to calculate frictional coefficients for the system.
Dissolution and absorption of ICI 49,455
Authors: Flanagan T H , Broad R D , Rubinstein M H , Longworth A R 
Published: April 2011

Abstract
The dissolution rate of ICI 49,455 (1-isopropyl-1,2,3,4-tetrahydro-β-carboline) from tablet and capsule formulations cannot be related to in vivo absorption in dogs. The rate of partitioning of the drug into organic solvents and its absorption in goldfish and through human buccal membrane depend on the pH of the solution. Absorption increases with decrease in the degree of ionization. The dissociation constant and the elimination rate of the drug in man are such that high blood levels after oral administration are unlikely to occur.
The influence of stereochemistry on pKa, rate of quaternization and partition coefficients of corynantheidine-type alkaloids
Authors: Beckett A H , Dwuma-Badu D 
Published: April 2011

Abstract
In alkaloids of the corynantheidine group, the rate of quaternization at N-4 and the pKa values give a measure of the degree of steric hindrance at this site due to the axial hydrogen at C-3 and the ethyl group at C-20. These hinder the availability of the lone pair of electrons on N-4 to electrophiles. Partition coefficients indicate that lipid solubility is associated with planarity of the molecules; this explains why the more planar isomers (allo and normal) are more highly metabolized in microsomes than the less planar isomers (pseudo and epiallo).
The preparation and pharmacological properties of ψ-corbasil
Authors: Farrugia M T , Hunter W H , Kirk G 
Published: April 2011

Abstract
The synthesis is described of threo-α-methyl noradrenaline (ψ-corbasil). The assignments of the erythro and threo configurations to corbasil and ψ-corbasil respectively are supported by the evidence of the nmr spectra. Some preliminary results are reported for the relative pharmacological activity of the two isomers at α- and β-adrenergic receptors.
A new preparation of the isolated intact trachea of the guinea-pig
Authors: Farmer J B , Coleman R A 
Published: April 2011

Abstract
A preparation is described in which the guinea-pig isolated intact trachea is subjected to repeated transmural electrical stimulation with alternating square wave pulses. The intraluminal pressure is continuously sensed by a pressure transducer. An increase in the intraluminal pressure is the predominant response to electrical stimulation. This response is prevented by low concentrations of atropine. After the initial rise a small fall in intraluminal pressure occurs; this is prevented by low concentrations of propranolol. The sensitivity of the preparation to various drugs is described.
Effects of salicylate on the incorporation of orotic acid into nucleic acids of mouse tissues in vivo
Authors: Janakidevi K , Smith M J H 
Published: April 2011

Abstract
In mice, given intraperitoneal injections of orotic acid-5-3H, two peaks of incorporation of radioactivity at 30 min and 6 h occurred in the RNA of kidney and of liver and its subcellular components. The concurrent administration of salicylate, in doses of 200 mg/kg body weight and above, significantly inhibited the incorporation of the labelled orotic acid at 30 min but not at 6 h.
Pharmacological screening of some Brazilian plants
Authors: Barros Glauce S G , Matos F J A , Vieira J E V , Sousa Mirian P , Medeiros Mary C 
Published: April 2011

Abstract
Forty-five species of plants from several botanical families growing in North East Brazil have been examined for toxicity on mice and small fishes, cat blood pressure and respiration, isolated toad heart and rectus abdominis muscle, guinea-pig ileum, rabbit duodenum and rat uterus. A high toxicity to mice and fishes was exhibited by aqueous (A) and ethanolic (B) extracts from Luffa operculata, Peschiera affinis, Pithecelobium multiflorum (gall) and Zizyphus joazeiro and by extract B from Pithecelobium multiflorum (stembark). Cardiorespiratory activity was shown by Annona squamosa, Byrsonima sericea, Crataeva tapia, Erythrina velutina, Fagara rhoifolia, Operculina macrocarpa, Perschiera affinis, Pithecelobium multiflorum, Spondias lutea and Zizyphus joazeiro. Extracts A and B from Operculina macrocarpa and Pithecelobium multiflorum, extract A from Luffa operculata and Zizyphus joazeiro and extract B from Crataeva tapia and Peschiera affinis promoted a contraction of the toad rectus abdominis muscle. Both extracts from Annona aquamosa and Fagara rhoifolia (leaf) provoked a spasmogenic effect on guineapig ileum and a spasmolytic one on rabbit duodenum. Extracts A and B from Pithecelobium multiflorum, Vitex gardneriana and Zizyphus joazeiro exhibited a spasmogenic activity on both preparations, while extracts A and B from Peschiera affinis and extract B from Erythrina velutina also evidenced a spasmolytic activity on both preparations. Oxytocic activity was shown by both extracts from Annona squamosa, Byrsonima sericea, Pithecelobium multiflorum and Vitex gardneriana.
Effect of some antiparkinsonian drugs on catecholamine neurons
Authors: Farnebo Lars-Ove , Fuxe Kjell , Hamberger Bertil , Ljungdahl Håke 
Published: April 2011

Abstract
The inhibitory effect of some antiparkinsonian drugs on the accumulation of catecholamines into rat dopamine and noradrenaline neurons was studied with isotope and histochemical fluorescence methods in vivo and in vitro. Benztropine was the most potent drug hitherto tested to inhibit accumulation of catecholamines into dopamine neurons and was effective down to a dose of 10mg/kg. Also ethybenztropine, brompheniramine, diphenylpyraline, chlorpheniramine and methixene, in doses of 50 mg/kg, inhibited accumulation of catecholamines. Atropine, scopolamine, benzhexol, diphenhydramine and many other antiparkinsonian agents were ineffective.
A new dry extract of cascara (Rhamnus purshiana D.C. bark)
Authors: Fairbairn J W , Simic S 
Published: April 2011

Abstract
The B.P. method of preparing a dry extract of cascara leads to significant breakdown of O-glycoside links in the active compounds. This is shown to be due to enzyme activity during percolation. A dry extract, containing most of the active glycosides originally present in the bark with no change in glycosylation status, can be prepared using boiling water as extracting solvent. A modification of the chemical assay process is recommended as well as the use of an official standardized extract with upper and lower limits for glycoside content.
Some effects of experimentally-produced cigarette smoke on the growth, vitamin C metabolism and organ weights of guinea-pigs
Authors: Hughes R E , Jones P R , Nicholas P 
Published: April 2011

Abstract
Guinea-pigs receiving a controlled dietary intake of L-xyloascorbic acid (ascorbic acid, vitamin C) inhaled experimentally produced cigarette smoke for periods of up to 20 min each day. Growth rate was significantly depressed by the smoke treatment, an effect at least in part attributable to a reduction in food intake. Growth of individual organs was not depressed to the same extent as that of the body as a whole. The lungs of the animals receiving smoke were significantly heavier than those of control animals (P &lt; 0·05). The concentration of ascorbic acid in the adrenal glands was significantly lower in the animals receiving smoke than in the controls (P &lt; 0·01). The smoke-induced depression of the adrenal gland ascorbic acid was apparent after 4 days; after 18 days marked adrenal hypertrophy accompanied the lowered ascorbic acid levels.
Plasma protein binding of chlorpromazine
Authors: Curry Stephen H 
Published: April 2011

Abstract
More than 90% of the plasma content of chlorpromazine over a concentration range from 0·008 to 15·1 μg/ml was bound to human plasma protein. Binding was affected by the pH of the aqueous medium; with few exceptions the higher values were obtained at the higher pH values. Binding was highest in some of the plasma samples from humans, and successively lower in plasma from dogs, rabbits and rats. Binding of chlorpromazine after administration of the drug to psychiatric patients, and after in vitro addition of the drug to plasma, was reversible. Variation in binding in plasma from different humans was marked; the amount bound varied from 91·0 to 99·0%. Thus the variation in the amount free was from 1·0–9·0%.
A note on the determination of dichlorophen and hexachlorophene in mixtures
Authors: Daisley R W , Olliff C J 
Published: April 2011

Abstract
Dichlorophen and hexachlorophene can be separated and estimated rapidly. Separation was achieved on thin-layer chromatograms using ethyl acetate containing 10% v/v of methanol and silica gel, the appropriate areas for each compound being collected and eluted with methanol. The absorbances of these solutions at 286 and 299 nm respectively were measured and compared with standard curves. Application of the method to several commercial formulations was successful.
The use of boronate derivatives in the characterization of catecholamines and related β-hydroxy-amines by gas liquid chromatography-mass spectrometry
Authors: Anthony G M , Brooks C J W , Middleditch B S 
Published: April 2011

Abstract
The gas chromatographic separation of various β-hydroxy-amines in the form of derived 1, 3, 2-oxazaborolidines is complemented by a mass-spectrometric study of cyclic boronates of natural catecholamines. These derivatives and their synthetic analogues yield characteristic mass spectra. Closely similar compounds, such as the n-butylboronates of the diastereoisomers (—)-ephedrine and (+)-ψ-ephedrine, give almost identical spectra but can be readily distinguished by their glc retention times. The same can be said for the positional isomer pairs synephrine and phenylephrine, and for octopamine and 4-deoxynoradrenaline. Mass-spectrometric fragmentation modes are postulated from a comparison of the shifts in the masses of fragment ions corresponding to various substituents in the group of biological amines studied. Additional correlations are derived from studies of methyl-, cyclohexyl- and phenyl-boronates.
1, 2-Disubstituted cyclohexanes as substrates of acetylcholinesterase and muscarinic agents. A re-investigation
Authors: Kay J B , Robinson J B , Cox B , Polkonjak D 
Published: April 2011

Abstract
The previously reported high rates of acetylcholinesterase-catalysed hydrolysis of (±)-cis- and (±)-trans-2-dimethylaminocyclohexyl acetate methiodide (Baldridge, McCarville & Friess, 1955) have been re-investigated, the enantiomers of each geometrical isomer being used. The cis-enantiomers were inactive as substrates and the trans-enantiomers were hydrolysed at a very slow rate. These results are confirmed by studies on muscarinic tissue (guinea-pig ileum) in which only a weak stimulatory response was given with the trans-enantiomers (the cis-enantiomers were inactive). With each of the test systems used, the acetylcholine receptor showed an inversion of the “normal” configurational specificity although the enantiomer potency ratio was small, a phenomenon which has been observed in previous reports of inversion of configurational specificity.
Stereochemical influences upon antihistamine activity. Further studies of isomeric 4-amino-1, 2-diarylbutenes
Authors: Casy A F , Ison R R 
Published: April 2011

Abstract
The acid-catalysed dehydration of some 4-amino-1, 2-diarylbutan-2-ols yields all four possible 4-amino-1, 2-diarylbutenes. The structure and configuration of pure isomers have been established from spectroscopic data, and the ability of these compounds to anatagonize histamine-induced contractions of the guinea-pig ileum is reported. The most potent derivatives are all cis(H/Ar)-4-amino-1, 2-diarylbut-2-enes. These results together with other data are discussed in terms of the possible structural and conformational requirements of histamine antagonists.
A comparison of the local anaesthetic-, “quinidine-like”- and adrenergic β-blocking-activities of five β-receptor antagonists
Authors: Davis W G 
Published: April 2011

Abstract
Propranolol, pronethalol, INPEA, MJ1999 and MJ1998 exhibit local anaesthetic activity when assessed by infiltration anaesthesia and at motor nerve endings but only propranolol, pronethalol and INPEA exhibit local anaesthetic activity on the phrenic motor nerve. All the β-adrenergic blocking agents exhibit a “quinidine-like” activity and there appears to be a close correlation between local anaesthetic and “quinidine-like” activities, which cannot be extended to include adrenergic β-receptor antagonism.
The effect of isoniazid and some anticonvulsant drugs on the γ-aminobutyric acid content of mouse brain in insulin hypoglycaemia
Authors: Saad Samir Fahmy 
Published: April 2011

Abstract
Phenobarbitone, prominal and primidone protect mice from insulin convulsions and raise their lowered cerebral hemisphere GABA content. Phenobarbitone and primidone are superior to prominal and produce a significant increase in the insulin depleted GABA content. Isoniazid potentiates insulin convulsions and significantly lowers the insulin depleted GABA content. It is probable that insulin depletion of cerebral hemisphere GABA content is a rationale of hypolgycaemic convulsions.
The transfer and penetration of fatty alcohols and fatty acids in relation to their self-bodying action in emulsions
Authors: Talman F A J , Rowan E M 
Published: April 2011

Abstract
The transfer of fatty alcohols and acids from an oil phase to an aqueous solution of surfactant has been examined. Also, penetration of the solid amphiphile by these surface-active agents has been observed by optical microscopy. The findings have been correlated with the flow behaviour of emulsions and gels containing these materials. The results indicate that before a fatty alcohol or acid, in conjunction with a surfactant, will have any self-bodying action in an emulsion two conditions must be fulfilled. Firstly, a portion of the alcohol or acid must migrate from the oil to the aqueous phase and secondly, the surfactant molecules must be of such size or shape or present in sufficient concentration to permit penetration of the amphiphile crystal lattice and the formation of a ternary liquid crystalline phase.
An in vitro model for drug absorption studies
Authors: Robertson J S , Bode O 
Published: April 2011

Abstract
The transfer of salicylic acid and of three sulphonamides from an aqueous phase of pH 2 or pH 5 through an intervening organic phase to an aqueous phase of pH 7.4 has been studied using a rotating cell. The manner of operation of the cell promotes rapid drug transfer without vortexing or emulsification of the phases. The rates of transfer of the drugs showed the anticipated pH dependance.
Some observations on the ageing of sodium chloride compacts
Authors: Rees J E , Shotton E 
Published: April 2011

Abstract
The diametrical crushing strength of an ideal system of compacted particulate material, and the relation between strength and mean compaction pressure depend on the time at which the strength is determined. Strength increases of over 100% during the first hour after compression are attributed to stress relief of the sodium chloride crystals and interparticulate bonds. The effects of elevated temperature, and also humidity, on the strength and physical structure of compacts are evaluated. Relaxation behaviour of compacts containing light liquid paraffin is also investigated.
Some problems encountered in attempting to estimate catecholamine turnover using labelled tyrosine
Authors: Persson T , Waldeck B 
Published: April 2011

Abstract
Rats were given [3H]tyrosine intravenously. The decrease of [3H]noradrenaline (3H-NA) and [3H]dopamine (3H-DA) from 2 to 6 h after the [3H]tyrosine injection was estimated in the cerebral cortex, brain stem, caudate nucleus, spinal cord and adrenal medulla. Half-lives were estimated with or without the tyrosine hydroxylase inhibitor H 44/68 or the dopamine-β-hydroxylase inhibitor FLA-63, given 2 h after the [3H]tyrosine. The influence of the inhibitors on endogenous noradrenaline was also studied. H 44/68 did not change the half-life of 3H-NA in the central nervous system but FLA-63 reduced it considerably. FLA-63 reduced endogenous noradrenaline more than did H 44/68. The mechanism responsible for the faster turnover of noradrenaline after FLA-63 has not yet been elucidated. In the adrenal medulla the [3H]adrenaline + 3H-NA level rose significantly from 2 to 6 h after the injection of [3H]tyrosine. The synthesis inhibitors prevented this rise, indicating that appreciable amounts of labelled precursors remain for a long time after the injection of the labelled tyrosine. Some problems encountered with the different methods for turnover determinations are discussed on the basis of these data.
Nuclear magnetic resonance spectroscopy of the trimethylsilyl ethers of some hydroxyphenylalkylamines
Authors: Forrest Janet E , Heacock R A , Forrest T P 
Published: April 2011

Abstract
A number of hydroxyphenylalkylamines have been converted into their trimethylsilyl ethers by the action of hexamethyldisilazane in pyridine. The derivatives are completely soluble in carbon tetrachloride and these solutions are suitable for nuclear magnetic resonance spectroscopy. The nmr spectra of 16 potentially biologically active phenylalkylamines have been obtained in this way. The spectral data are presented and the significance of the results discussed.
Reduction of gastric acid secretion and ulcer formation by 3,3-dimethyl-1-(3-methylaminopropyl)-1-phenylphthalan (Lu 3–010); an inhibitor of noradrenaline uptake
Authors: Lippmann W 
Published: April 2011

Abstract
Lu 3–010 [3,3-dimethyl-1-(3-methylaminopropyl)-1-phenylphthalan], administered intraperitoneally, blocks the uptake of [3H]noradrenaline into the mouse and rat heart and has an activity 5 times greater than imipramine and comparable to that of desipramine. Lu 3–010 inhibits basal gastric acid secretion in the rat and is 4 and 2 times more potent than imipramine and desipramine, respectively. The drug is about 9 times more potent than desipramine in preventing the pentagastrin-induced stimulation of gastric acid secretion in the rat. Lu 3–010 reduces the incidence of stress-induced gastric lesions in the rat, exhibiting an ED50 ± s.e. of 6.3 ± 1.4 mg/kg, and at 10 mg/kg, ulcer development in the 17-hour Shay test is reduced by 50%.
The identification, isolation, and preservation of Δ9-tetrahydrocannabinol (Δ9-THC),
Authors: TURK ROBERT F , MANNO JOSEPH E , JAIN NARESH C , FORNEY ROBERT B 
Published: April 2011

Abstract
(—)-trans-Δ9-Tetrahydrocannabinol (Δ9-THC) was isolated from marihuana plant extract, by adsorptive column and glc. The adsorptive column chromatography method consisted of chromatographing marihuana extract on a column packed with a mixture of silica gel (gas chromatography grade (100/120 mesh), silver nitrate and calcium sulphate (CaSO4·H2O) (3:1:0·5) with benzene as the eluting solvent. The glc method consisted of chromatographing the extract on a 3 ft silanized glass column (3/8 inch o.d.) packed with 1·5 ft of 2% QF-1 and 1·5 ft of 2% OV-17 on chromosorb W, AW 30–60 mesh, prep grade. A purity of 99% for the isolated Δ9-THC was confirmed by infrared spectroscopy, nuclear magnetic resonance, mass spectroscopy. The effects of storage conditions on Δ9-THC stability, monitored by glc, indicated the best method for preserving Δ9-THC was at 0°, protected from light, stored under nitrogen.
The spontaneous electrical and mechanical activity of the longitudinal smooth muscle of the rabbit duodenum and its modification by drugs and temperature changes
Authors: SMALL R C , WESTON A H 
Published: April 2011

Abstract
The electrical and mechanical activity of strips of longitudinal smooth muscle from the rabbit duodenum was recorded using the sucrose gap method. The muscle exhibited rhythmic tension changes each of which was associated with a slow potential wave of electric depolarization surmounted by a burst of spike activity (a multispike complex). Cooling the tissue reduced the frequency of tension waves and multispike complexes. Catecholamines produced a reduction in the amplitude of tension waves. This was associated with hyperpolarization and decreased spike activity. Slow wave frequency and amplitude were unaffected. Acetylcholine, methacholine and histamine produced tension wave fusion associated with depolarization and increased spike activity.
dl-5-Hydroxytryptophan-induced changes in central monoamine neurons after peripheral decarboxylase inhibition
Authors: FUXE KJELL , BUTCHER LARRY L , ENGEL JÖRGEN 
Published: April 2011

Abstract
The histochemical effects of 500 and 1000 mg/kg of dl-5-hydroxy-tryptophan (5-HTP), both alone and in combination with a peripheral decarboxylase inhibitor (seryl-trihydroxy benzyl hydrazine; Ro 4–4602) have been examined on central monoamine neurons of rats by the Falck-Hillarp fluorescence technique that demonstrates monoamines and their precursors. 5-HTP alone or together with Ro 4–4602 caused only weak intraneuronal accumulation of 5-HT in the central 5-HT neurons, in spite of an increased entry of 5-HTP into the brain after Ro 4–4602 treatment, as shown by an increase in the specific neuropil fluorescence and a reduction of 5-HT accumulation in the cells of the capillary walls. Ro 4–4602 markedly potentiated the effects of 5-HTP on the central dopamine neurons, many of which became clearly yellow fluorescent. The mechanism of dopamine depletion by 5-HTP is probably therefore mainly one of displacement. The effects on the noradrenaline neurons were also potentiated by Ro 4–4602 pretreatment, the neurons exhibiting a yellow-green fluorescence. This depletion may therefore also be mainly be due to amine displacement. It is concluded that the ability of the 5-HT neurons to take up and accumulate 5-HT in the presence of 5-HTP is relatively low in spite of large amounts of 5-HTP present in the brain neuropil after extracerebral decarboxylase inhibition.
Spasmolytic action of adenosine on the guinea-pig ileum
Authors: SEHORN S L , BOROWITZ J L 
Published: April 2011

Abstract
Adenosine (10−5M) reduces the contractile response of the guinea-pig isolated ileum to 5-hydroxytryptamine or barium more than the responses to acetylcholine or histamine. Adenosine also inhibits the contractile response of the guinea-pig ileum to a calcium-free medium. These results suggest that adenosine effects a blockade of the indirect responses to barium or 5-hydroxytryptamine mediated through intrinsic nerves and has a weak direct inhibitory effect on the smooth muscle cells of this tissue.