bluuebunny/crossref_metadata_2025 huggingface dataset:
An apparatus for the investigation of die wall friction during compaction
Authors: Lewis C J , Train David
Published: April 2011

A “moving-die” apparatus is described for use in the investigation of die wall friction during the compaction of powders. The powder can be compressed at constant rates varying from 344–860 kg/sec; the die can be moved at a constant rate at values of 0.1–0.25 cm/sec. The apparatus can also be used to apply the force necessary to cause shear in a punch penetration test for the measurement of shear strength of the ejected compacts. Preliminary experiments with 20–30 mesh crystalline sucrose indicate that values of die reaction, Fd, and ejection force, Fe, increase with increased applied pressure. For a given compaction pressure, Fe and Fd decreased as the rate of application of the compacting force increased. For the range of rates available Fd was independent of the rate of movement of the die. The shear strength of ejected compacts prepared at a constant pressure increased with increase in the rate at which the shear force was applied.
A simple liquid flow recorder
Authors: Ai-Seng Lee , Lin Robert C Y
Published: April 2011

A liquid flow recorder of simple design which can be easily constructed with readily obtainable material at low cost is described. It is used with a piston recorder and a time interval marking clock to measure the rate of liquid flow over a range of a few drops to 50 ml/min.
The action of arsenic on Bacillus cereus
Authors: Mandel H George , Mayersak Jerome S , Riis Margit
Published: April 2011

Sodium arsenite (0–4 mm) inhibited the growth of exponentially growing Bacillus cereus, whereas sodium arsenate was growth-inhibitory only at 10 mm concentration. When the phosphate concentration was reduced sharply, 3.3 mm sodium arsenate inhibited growth, whereas the inhibitory effect of arsenite was independent of phosphate concentration. Neither arsenite nor arsenate produced any specific effects on the incorporation of precursors into ribonucleic and deoxyribonucleic acids, protein or cell wall, in support of the concept that their actions were at stages of energy utilisation rather than biosynthesis of macromolecules. Although some 74arsenate may have been bound by cells during inhibition of growth, 74arsenite was selectively and potently concentrated in micro-organisms. There was no evidence for the formation of arsenic-containing nucleic acids nor were labelled organic intermediates found. No instance of interconversion between pentavalent and trivalent states of arsenic could be established, and it was concluded that both compounds inhibited the growth of B. cereus by separate mechanisms.
The structure of rubreserine, a decomposition product of physostigmine
Authors: Robinson B
Published: April 2011

Confirmation of the structure of rubreserine as the resonance hybrid (I) ←—⋙ (II) has been obtained by comparison of its ultraviolet, infrared, and proton magnetic resonance spectra with those of adrenochrome (III) ←—⋙(IV).
A note on the alkaloidal content of Datura innoxia Miller
Authors: Shah C S , Khanna P N
Published: April 2011

Hyoscyamine, hyoscine and meteloidine have been found in the leaves, herbs and roots of D. innoxia Miller, but only hyoscyamine and hyoscine are present in flowers, pericarps and seeds. In addition, the roots contain 7-hydroxy-3,6-ditigloyl-oxytropane, (–)-3α,6β-ditigloyloxytropane, tropine and pseudotropine. All the parts of the plant contain a higher percentage of hyoscyamine or hyoscyamine and meteloidine mixture than of hyoscine.
Effects of enzymes on Yucca glauca Nutt. and other steroid-yielding monocotyledons
Authors: Blunden G , Hardman R , Wensley W R
Published: April 2011

A routine assay procedure for steroidal sapogenins in plant tissue is described in which the endogenous enzymes are allowed to function before the tissue is treated with acid. Inhibition of this enzyme action either by disintegration of the tissue in acid or by autoclaving gave a low yield from the leaf, corm, rhizome, tuber or root of the genera so tested (Agave, Aletris, Asparagus, Smilax, Trillium and Yucca). Oven-dried material, in powder, needed to be incubated with water for one day for the full sapogenin-affording enzyme activity to occur. When autoclaved leaf of Yucca glauca Nutt. was incubated with commercial cellulase it gave about 80% of the yield of sapogenin afforded by the unheated leaf. The yield is also given when emulsin or pectinase is used instead of the endogenous enzymes.
Action of the neurohypophysial hormones on the vascular system of the male monkey and the rooster
Authors: Chaudhury R R , Tarak T K
Published: April 2011

Oxytocin caused a fall in the blood pressure of the normal, oestrogen- and progesterone-treated male monkeys. Vasopressin always caused a rise of blood pressure in similarly treated monkeys and oestrogen and progesterone treatment did not enhance the pressor response. Oxytocin also caused a fall in the blood pressure of the normal, oestrogen- and progesterone-treated rooster.
The response to transmural stimulation of isolated arterial strips and its modification by drugs
Authors: Paterson Gavin
Published: April 2011

Transmural electrical stimulation of isolated aortic strips of rabbits, induced contractions of the muscle which were blocked by concentrations of cocaine and lignocaine which augmented the response to noradrenaline. The adrenergic neurone blocking agents bretylium, guanethidine and bethanidine also blocked selectively the response to transmural stimulation. With bretylium and guanethidine the responses to noradrenaline were augmented. α-Receptor blockade with piperoxan, phentolamine, phenoxybenzamine and dihydrogenated ergot alkaloids also blocked the responses to transmural stimulation. Cocaine in low concentration and dexamphetamine augmented the responses to electrical stimulation. They also delayed onset of block with adrenergic neurone blocking drugs and reversed this when it was already established. Hexamethonium and pentolinium, in concentrations which in other tissues are known to cause complete blockade of ganglionic transmission. had no effect on electrical stimulation. It is concluded that the responses to electrical stimulation are the result of excitation of post-ganglionic adrenergic axons in the walls of the arterial preparation. Strips of common carotid, superior mesenteric, renal, pulmonary and common iliac arteries of the rabbit gave responses to electrical stimulation similar to those of the aorta.
Competitive blockade of adrenergic α-receptors and histamine receptors by thymoxamine
Authors: Birmingham A T , Szolcsányi J
Published: April 2011

The adrenergic α-receptor blocking activity of 4-(2-dimethylaminoethoxy)-5-isopropyl-2-methylphenyl acetate, thymoxamine, was quantitatively investigated on the vas deferens of the guinea-pig and on arterial strips from guinea-pigs, rabbits, cats and dogs. The blockade fulfilled the established criteria for competitive antagonism of noradrenaline. On these various tissues the pA2 was about 7.0; thymoxamine was more potent than piperoxan and less potent than dihydroergotamine. There was no evidence of β-receptor or 5-hydroxytryptamine receptor blocking activity. Against histamine as the agonist on the guinea-pig ileum, thymoxamine was a competitive antagonist with a pA2 of about 6.5.
Occurrence of anhydrovitamin A and retro-vitamin A in pharmaceuticals; their biological potency and effect on the assay of vitamin A
Authors: Varma T N R , Erdody P , Murray T K
Published: April 2011

Analyses of commercial samples of liquid multivitamin preparations revealed that many contained anhydrovitamin A, retro-vitamin A ether, vitamin A ether, and retro-vitamin A alcohol in varying proportions. Anhydrovitamin A and retro-vitamin A ether were present in greater amounts than the other vitamin A-derivatives. Anhydrovitamin A and retro-vitamin A ether had no measurable potency in the liver storage and vaginal smear assays, whereas retro-vitamin A acetate was 12% as potent as vitamin A. These compounds interfered with the assay of vitamin A by the United States Pharmacopeia XVI and British Pharmacopoeia 1963 methods but the interference could be eliminated by chromatography.
Quantitative separation of riboflavine from vitamin mixtures
Authors: Wahba Nagi , Fahmy Emil
Published: April 2011

A method for separating riboflavine from vitamin mixtures is described. The acidified aqueous solution is passed through a small column of large particle size talc on which the riboflavine is selectively and quantitatively adsorbed. Successive washings with 0–01 n hydrochloric acid and 5–10% dioxan remove the other components almost completely. The vitamin, eluted with 20% dioxan, is measured spectrophotometrically.
Some pyrroline derivatives as potential antiinflammatory agents
Authors: Beckett A H , Lee Calvin M , Sugden J K
Published: April 2011

Eight N-substituted-4-carbethoxy-2-oxo-3-hydroxypyrrolines and six N-β-phenethyl-2-oxo-3-arylaminopyrrolines were synthesised and tested for possible anti-inflammatory action. Infrared and nuclear magnetic resonance spectral evidence is presented to show that in the solid state and in solution (CDCl3) these compounds exist solely as the tautomer in which the double bond is within the heterocyclic ring. The compounds showed no important pharmacological activity.
A comparison of aralkylamines and aralkylguanidines as antagonists of adrenergic neurone blockade
Authors: FIELDEN R , GREEN A L
Published: April 2011

Structure-activity relationships have been studied for aralkylamines and aralkylguanidines which restore the responses of the nictitating membranes to nerve stimulation in anaesthetised cats given sympathetic blocking drugs. This reversing action was largely specific for adrenergic neurone blockade; blockade of sympathetic ganglia or of α-adrenergic receptors was unaffected. (+)-Amphetamine was the most active amine and N-benzyl-N-methylguanidine was the most active guanidine. In mice, ptosis resulting from adrenergic neurone blockade was much more readily prevented or abolished by the aralkylamines and aralkylguanidines than was ptosis caused by other types of sympathetic blocking agent. The most potent antagonist of ptosis was N-(2-phenylcyclopropyl)guanidine which was about ten times as active as amphetamine. The relative antagonistic potencies of 2 amines and 8 guanidines were virtually identical for all types of adrenergic neurone blocking drug, regardless of whether or not they cause noradrenaline depletion. The prevention of guanethidine-induced ptosis was always accompanied by some reduction in the extent of heart-noradrenaline depletion, but the minimum dose of antagonist required to prevent ptosis completely was always lower than that required to eliminate depletion.
The relation between noradrenaline content of rabbit heart muscle and the amount of k-strophanthin needed to produce arrhythmias
Authors: ANGELUCCI L , LORENTZ G , BALDIERI MIRELLA
Published: April 2011

Possible relations between the sensitivity of the heart to the arrhythmia-inducing property of k-strophanthin and myocardial storage of noradrenaline were investigated. Sensitivity to the glycoside was increased in rabbits pretreated with reserpine in doses which depleted noradrenaline, but not in rabbits pretreated with tyramine in doses which are known to reduce noradrenaline content. Sensitivity to the glycoside was restored to normal by an infusion of noradrenaline not earlier than 72 hr after reserpine treatment, but not by an infusion given at 24 hr. Infusion of noradrenaline did not itself reduce the sensitivity to k-strophanthin in normal rabbits. The glycoside acutely reduced the myocardial store of adrenaline and noradrenaline in normal rabbits. The possibility that cardiac sensitivity to k-strophanthin is regulated by bound but not by unbound noradrenaline is discussed.
A note on the assay of the contribution of the pentose phosphate pathway to glucose metabolism in human red cells
Authors: STURMAN J A , SMITH M J H
Published: April 2011

When human red cell suspensions were incubated with [14C1] glucose a substantial fraction of the incorporated radioactivity was found in phosphate compounds. If some of these phosphates are precursors of 14CO2 then an error is introduced into the conventional calculation of the proportion of glucose metabolised by the pentose phosphate pathway. The existence of this error was demonstrated and its magnitude was assessed by studying the effects of the subsequent addition of unlabelled glucose to the reaction mixtures in either the absence or the presence of methylene blue.
Some aggregation effects observed with an emulsion dispersed in saline containing cetrimide
Authors: GROVES M J
Published: April 2011

Aggregation behaviour has been observed when an emulsion containing liquid paraffin and cetostearyl alcohol as disperse phase is diluted in saline containing cetrimide below the critical micelle concentration. This aggregation has been examined with the Coulter Counter. Under standardised conditions the apparent size of the aggregated particles is directly related to the logarithm of the molar concentration of the cetrimide present over three orders of magnitude. Above the critical micelle concentration the particles appear to be deaggregated.
Modification of drug responses by hydrolytic Enzymes
Authors: CUTHBERT ALAN W
Published: April 2011

α-Chymotrypsin and phospholipase enzymes have been used to alter the cell membranes of the smooth muscle of the guinea-pig taenia coli. The effects of these treatments on the electrical and mechanical responses of the muscle to acetylcholine have been studied. Prolonged treatment with both enzymes causes depolarization with a consequent loss of acetylcholine sensitivity. After controlled trypsinization a membrane response to acetylcholine was obtained in the absence of a mechanical response. The sensitivity of the taenia coli to acetylcholine was depressed by controlled phospholipolysis without affecting the membrane potential or contractile apparatus. The implications of these findings are discussed.
The in vitro metabolism of mitragyna alkaloids of corynantheidine structure
Authors: BECKETT A H , MORTON D M
Published: April 2011

CORYNANTHEIDINE has the structure (I) and, apart from cis-trans geometry about the C(16)–(17) double bond, four diastereoisomeric pairs of enantiomorphs are possible.
The use of the Coulter Counter to detect the inactivation of preservatives by a non-ionic surface-active agent
Authors: PARKER M S , BARNES M , BRADLEY T J
Published: April 2011

Bacterial and mould spores undergo a germination swelling process which can be accurately measured using a Coulter Counter. The efficacy of preservatives can be assessed by their action in suppressing germination swelling of spores. The antagonism between polysorbate 80 and several preservatives has been demonstrated by measuring swelling of spores in the presence of preservatives and preservative-surfactant mixtures.
Effect of cold stress on the subcellular distribution of noradrenaline in the rat heart
Authors: CHANG C C , SU C Y
Published: April 2011

Rats were exposed to cold (4°) for 2 hr to study the effect of increased sympathetic activities on the subcellular distribution of noradrenaline in the heart. Cold-exposure caused about 30% decrease of total noradrenaline contents in both auricles and ventricles of normal or adrenalectomized rats. This depletion of noradrenaline caused by cold was completely prevented by pretreatment of the rat with hexamethonium chloride. Measurement of the subcellular distribution of noradrenaline revealed that the percentage depletion in particle-bound amine in both auricles and ventricles was greater than in the supernatant noradrenaline. It is suggested that the noradrenaline in the particulate fraction is the functional pool of the amine available for release by nerve impulses.
A new method for the determination of globule size distribution of emulsions by dielectric constant measurement
Authors: KAYE R C , SEAGER H
Published: April 2011

A new method for the determination of globule size distribution of emulsions prepared with non-ionic surfactants by ascent rate analysis is described. The proportion of dispersed phase in a narrow layer of dilute emulsion situated at a known height in a capacitance cell is determined at suitable time intervals and by the application of Stokes' Law, the droplet size distribution is calculated.
Steroidal monoquaternary ammonium salts with non-depolarizing neuromuscular blocking activity
Authors: LEWIS J J , MARTIN-SMITH M , MUIR T C , ROSS H H
Published: April 2011

A series of ten 2β- or 3α-steroidal monoquaternary ammonium salts, having androstane or pregnane skeletons and related in structure to acetylcholine by possession of an oxygen function on the carbon atom next but one to the quaternary nitrogen atom, were investigated for neuromuscular blocking activity in vivo in the cat, hen and mouse and in vitro on the frog rectus muscle and on the rat phrenic nerve diaphragm preparation. All compounds displayed typical non-depolarizing activity, the duration of block being significantly less than that for (+)-tubocurarine in the cat and the hen. The potency of the salts was low with the most active compound, 3α-acetoxy-2β-piperidino-5α-androstan-17-one methobromide, being 1/16th as active on a molar basis in the cat as (+)-tubocurarine.
Degraded and undegraded carrageenans and experimental gastric and duodenal ulceration
Authors: ANDERSON W , SOMAN P D
Published: April 2011

The prevention of histamine-induced gastric and duodenal ulceration in the guinea-pig has been examined using a series of undegraded and degraded carrageenans. Undegraded carrageenans were active at lower doses than degraded carrageenans. The high viscosity of the undegraded carrageenans in solution prevented their use in larger doses. Degradation of carrageenan without serious loss of sulphate, gives a product which allows the dose to be increased to an extent that its effect more than offsets the slight loss in activity caused by the degradation. No single feature of carrageenan structure can be related to anti-ulcer activity although degradation, and hence reduction of molecular size, generally reduces activity. Sulphate contents over 30% have little apparent effect on activity; κ-carrageenans were not consistently different in anti-ulcer activity from Λ-carrageenans. This contrasts with the antipeptic activity of carrageenans where κ-carrageenans are less active than their Λ-counter-parts. As with antipeptic activity, the degree of anti-ulcer activity is probably determined by a combination of structural features which includes molecular size and polyanionic properties.
Mechanism of the protective effect of reserpine on aggregated mice treated with (+)-amphetamine
Authors: MENON M K , DANDIYA P C
Published: April 2011

Experiments were made to see if the effect of reserpine in protecting aggregated mice from the toxic effect of (+)-amphetamine depended on the hypothermia or on the depletion of brain noradrenaline it induces. In aggregated mice, a 7 mg/kg dose of amphetamine elevated body temperature, lowered the level of brain noradrenaline and caused 100% mortality. In reserpinized aggregated mice, amphetamine did not cause hyperthermia or any further depletion of brain noradrenaline. Prevention of the hypothermic effect of reserpine by keeping amphetamine-treated reserpinized animals at a higher environmental temperature markedly lowered the protective effect of reserpine. When also the depletion of noradrenaline by reserpine was antagonized by dopa, reserpine no longer protected aggregated mice from the toxic effect of amphetamine. The lowering of 5-hydroxytryptamine content brought about by reserpine remained unaltered during these procedures. Complete protection against amphetamine toxicity was also offered by α-methyl-1-tyrosine in doses which lowered brain noradrenaline to almost the same extent as reserpine, but which did not lower temperature or brain 5-hydroxytryptamine. When the body temperature of aggregated mice with brain noradrenaline lowered by α-methyl-1-tyrosine was elevated by subjecting the animals to heat stress, the protective effect was reduced. Hypothermia induced by reserpine could thus be related to its noradrenaline-depleting action. The results show that both properties contribute to reserpine's protective action. However, the abolition by dopa of this protective effect of reserpine and the complete protection offered by α-methyl-1-tyrosine without hypothermia suggest that depletion of brain noradrenaline plays the more important role in the protective effect of reserpine.
The relation between primidone and phenobarbitone blood levels
Authors: Bogan James , Smith Hamilton
Published: April 2011

A dose of primidone or one fifth of the same weight of phenobarbitone produced equal levels of phenobarbitone in the blood.
The hydrolysis of acetylsalicylic acid by liver microsomes
Authors: Howes J F , Hunter W H
Published: April 2011

Pretreatment of rats and guinea-pigs with phenobarbitone or phenylbutazone leads to a decrease in the rate of hydrolysis of acetylsalicylic acid in vitro by liver microsomes, treatment with phenacetin does not.
Use of the analogue computer to predict the distribution and excretion of drugs under conditions of fluctuating urinary pH
Authors: Beckett A H , Boyes R N , Tucker G T
Published: April 2011

An analogue computer program, incorporating a previously established relation between urinary pH and amphetamine excretion, has been used to predict the quantitative excretion of the drug under normal conditions of fluctuating urinary pH. Under the same conditions, a comparison has been made of computer predicted body levels of amphetamine after administration of the drug in a single solution dose, three divided solution doses, and in various prolonged-release formulations. Advantages of sustained-release preparations are indicated and specifications for a theoretically ideal sustained-release formulation are suggested.
Cocaine-sensitive uptake of sympathomimetic amines in nerve tissue
Authors: Ross S B , Renyi A L , Brunfelter B
Published: April 2011

The uptake of [3H]octopamine, [3H]norephedrine and [3H]phenylethanolamine in slices of cerebral cortex and heart of the mouse was investigated. Cocaine inhibited the uptake of octopamine but had no effect on that of the other two amines, whose uptake seems to be a pure physico-chemical partition between the tissue and the solution. Together with previous results, these indicate that the cocaine-sensitive uptake is linked with the hydroxyl groups in the benzene nucleus and particularly with that in the meta position. The results bear out the view that the potentiating effect of cocaine on the direct effect of sympathomimetic amines is due to inhibition of the uptake of the amines in sympathetic nerves, but they contradict the assumption that the antagonizing effect of cocaine on the indirect action of the amines is due to inhibition of the amine uptake.
Toxicity of cryoprotective agents at 30°
Authors: Karow Armand M , Carrier Oliver , Clower Ben R
Published: April 2011

The toxicity of four cryoprotective agents (glycerol, dimethylsulfoxide, dextran, magnesium ion) as a function of time was assessed at 30° on isolated rabbit atria. Glycerol, 2·0 M, in Ringer solution killed all atria in less than 30 min. Atria tolerated 2·1 M dimethylsulphoxide in Ringer for 1 hr, 0·7 M glycerol in Ringer for 4 hr, 6% (w/v) dextran in saline for 6 hr and 6·6 times 10−2 M magnesium chloride in Ringer for 8 hr. After washing out the cryoprotective agents the tissue was examined histologically and for its response to isoprenaline, MJ-1999 [4,2-(isopropylamino-10-hydroxyethyl)methanesulphonilide, a β-blocking agent] and isoprenaline and ouabain. These tests were the more sensitive indicators of functional integrity.
Some aspects of the pharmacology of ibufenac, a non-steroidal anti-inflammatory agent
Authors: Adams S S , Hebborn P , Nicholson J S
Published: April 2011

When given orally to animals ibufenac has a range of potencies 2 to 4 times that of aspirin. It also suppresses thurfyl nicotinate erythema in man. Like certain other analgesic-anti-inflammatory-antipyretic drugs, when administered intravenously it suppresses bradykinin-induced bronchoconstriction in the guinea-pig. It has no glucocorticoid activity. Ibufenac, a compound chemically unrelated to existing antirheumatic drugs, can thus be classified as a non-steroidal anti-inflammatory (antirheumatic) agent.
The effect of the concentration of the water-soluble component, on the rheology of some oil-in-water emulsions containing long-chain alcohols
Authors: Talman F A J , Davies P J , Rowan E M
Published: April 2011

The effect of the concentration of two non-ionic water-soluble components—Sorbester Q12 (polyoxyethylene sorbitan monolaurate) and cetomacrogol 1000—and two ionic water-soluble components—cetrimide and sodium lauryl sulphate—on the rheology of some emulsions has been examined. Emulsions containing oleyl and lauryl alcohol exhibited an increase in consistency with increasing surfactant content. Maximum values for static yield value and apparent viscosity were found to occur with cetostearyl alcohol as the oil-soluble component. The values of the rheological parameters for products containing ionic surfactants tended to be higher than for non-ionics, but molal plots (and preliminary studies with Texofor N4, Texofor FX170 and Solumin FX170SD) suggested that this was an effect due to molecular weight rather than charge.
A note on a simple estimation of amphetamine, methylamphetamine and ephedrine in horse urine
Authors: Karawya M S , El-Keiy M A , Wahba S K , Kozman A R
Published: April 2011

A chromatographic separation of amphetamine, methylamphetamine and ephedrine from horse urine is possible on alkaline Silica Gel G plates developed with acetone-methanol (1:3). After elution, the bases are determined colorimetrically. The intensity of the violet colour resulting from the nitration of amphetamine is measured in a Unicam SP1300 colorimeter using filter No. 1 (sensitivity 50–250 μg). The colour produced by the interaction of methylamphetamine, sodium nitro-prusside, acetaldehyde and triethanolamine is measured at 590 mμ (sensitivity 200–2,000 μg). Ephedrine was determined by measuring the intensity of the brown colour of its dithiocarbamate at 440 mμ (sensitivity 100–900 μg).
Release of oxytocin contributes to the natriuretic action of aminophylline in rats
Authors: Lockett Mary F , Gwynne H L
Published: April 2011

Aminophylline, 0·25 to 2·0 mg intramuscularly, caused diuresis, natriuresis and increase in the Na/K of the urine in the 1 hr period after injection into normal hydrated or unhydrated rats. The urinary changes induced by 2 mg aminophylline and by 8 mU oxytocin equated. Salt-maintained adrenalectomized rats were fully sensitive to the diuretic, natriuretic action of aminophylline. The Na/K in the urine decreased at the 2 mg dose level. Hypophysectomy abolished and neuro-hypophysectomy markedly decreased the diuretic natriuretic action of aminophylline in unanaesthetized rats. Under ethanol-pentobarbitone anaesthesia the diuretic natriuretic action of 0·4 mg aminophylline intravenously lasted 30–40 min in normal rats, and for less than 10 min in neurohypophsectomized rats. The duration of the cardiovascular response to aminophylline was 7–8 min. Thioglycollate-labile oxytocic activity, not detectable in the arterial plasma of control animals, was demonstrable in the arterial plasma of normal rats 8–12 min after 0·5 mg aminophylline intravenously.
The determination of bupivacaine, lignocaine and mepivacaine in human blood
Authors: Reynolds Felicity , Beckett A H
Published: April 2011

A specific method for the quantitative analysis of bupivacaine, lignocaine and mepivacaine in blood, in clinically occurring concentrations, using gas-liquid chromatography, is described. The extraction procedure yields a recovery of 97·5 (±5)%, and the chromatographic conditions allow concentrations as low as 0·04 μg/ml of local anaesthetic in 2 ml of whole blood to be measured. The method has a standard deviation of 5·4%. No interference is encountered from commonly used premedicant or general anaesthetic drugs.
The extraction of azovan blue from precipitated plasma proteins
Authors: Gardiner J E
Published: April 2011

The paper describes a method for the estimation of azovan (Evans) blue in plasma proteins precipitated by trichloroacetic acid. The precipitate is dissolved in a strong solution of urea and an anionic detergent; the dye is absorbed on a cellulose column, from which it can be eluted by alkaline acetone-water. The method allows information to be obtained about drug uptake and plasma volume without the need for additional blood samples. It has been used with cat, rabbit, rat and guinea-pig plasma.
Effects of nicotine on motor co-ordination and spontaneous activity in mice
Authors: Morrison Cathleen F
Published: April 2011

Doses of nicotine (0·2 and 0·4 mg/kg subcutaneously) which depress spontaneous activity, improve the ability of mice to remain on a rotating rod, indicating that the reduction in activity is not due to non-specific disruption of motor ability.

The performance of rats trained to press a bar for water rewards is stimulated by small subcutaneous doses (0·05, 0·1 mg/kg) of nicotine; larger doses (0·2, 0·4 mg/kg) briefly reduce the rate of bar-pressing before increasing it (Morrison, 1967). The larger doses also depress spontaneous motor activity in mice (Morrison & Armitage, 1967). In the present experiments a rotating rod (Dunham & Miya, 1957) was used to test whether the depresssion of spontaneous activity caused by nicotine is a result of motor incapacity.
The mechanism of action of 2-halogenoethylamines at the adrenergic α-receptor and a further investigation of the “spare receptor” hypothesis
Authors: Moran J F , Triggle C R , Triggle D J
Published: April 2011

The evidence for “spare-receptors” has been examined in the adrenergic α-receptor system of the rat vas deferens using N-(2-bromoethyl)-N-ethyl-l-naphthylmethylamine (SY.28) and NN-dimethyl-2-phenylethylamine hydrobromides as the antagonist species. It is clearly demonstrated that “spare-receptors” are not present in this tissue and that the observed parallel shift of the dose-response curve of noradrenaline produced by SY.28 is due to a competitive reversible phase of action of the corresponding ethyleneimine species rather than to the presence of “spare-receptors”. Additionally, these experiments have revealed the existence of a significant non-competitive reversible phase of action of SY.28. From radiochemical studies and the observed first order recovery of tissue response following blockade by NN-dimethyl-2-bromo-2-phenylethylamine, it is concluded that the α-receptors in the rat vas deferens are indistinguishable from the α-receptors in the rabbit aorta in their behaviour towards this agent. From these results and those of others, it may be concluded that there is no existing evidence for “spare receptors” in adrenergic α-receptor systems.
On the mechanism of 5-hydroxytryptamine release by thymoleptics
Authors: Carlsson A , Jonason J , Lindqvist M
Published: April 2011

Rabbits were treated with nialamide followed by chlorimipramine, imipramine, desipramine or amitriptyline. Cortical brain slices were prepared and incubated with Krebs-Henseleit solution. Release of 5-hydroxytryptamine (5-ht) into the incubation medium was measured. Chlorimipramine, imipramine and amitriptyline caused release of 5-ht, whereas desipramine was without effect. The ability of cortical brain slices to retain 5-ht was dependent on energy supply, involving both aerobic and anaerobic metabolism. The data support the view that the antidepressant drugs block the membrane pump of 5-ht neurons. The observations also indicate that 5-ht is involved in thermoregulation.
A simple infrared spectrum retrieval system
Authors: Curry A S , Read J F , Brown C
Published: April 2011

The retrieval of an unknown spectrum from a medium-sized collection (up to 10,000) of infrared curves has been studied and a system based on a film feature card using microfilm storage developed. Tests of alternative methods of coding resulted in the choice of the six most intense absorption peaks in defined areas of the spectrum. Correct identification within 1–2 min is achieved in over 95% of searches. The system is compact, easy to operate, relatively inexpensive and easily perused.
The relation between blood levels and urinary excretion of amphetamine under controlled acidic and under fluctuating urinary pH values using [14C]amphetamine
Authors: Beckett A H , Salmon J A , Mitchard M
Published: April 2011

Plasma, blood cell and urine levels of amphetamine were determined after the oral administration of S-(+)-[14C]amphetamine sulphate to two subjects under conditions of controlled acidic and fluctuating urinary pH. The decline in plasma concentration of the drug was more rapid under the controlled acidic conditions than under conditions of fluctuating urinary pH. Under controlled conditions, the concentration time profiles of drug and metabolite in urine or plasma (as opposed to body levels), were suitable for kinetic analysis. The apparent rate of urinary excretion of amphetamine was proportional to its plasma concentration only under the controlled acidic urinary conditions. Amphetamine was cleared from blood more rapidly than could be accounted for by glomerular filtration under acid conditions, but when urinary pH fluctuated, clearance of the drug could be accounted for by this route.
The carvone and dillapiole content of dill fruits by gas chromatography without preliminary distillation
Authors: Betts T J
Published: April 2011

Cold hexane extracts of sixteen specimens of dried dill fruit were examined for their content of carvone and dillapiole by gas chromatography. Dillapiole was absent from “European dill” (even Indian grown), and present in “Indian dill” (including European grown) in about twice the weight of carvone. These two forms of dill are otherwise less distinct than the forms of fennel which are referred to one species.
A screening method for vasodilator drugs
Authors: Gay W S , Rand M J , Ross P
Published: April 2011

The use of the isolated perfused central artery of the rabbit ear for screening vasodilator drugs is described. The effects of these drugs are shown by reduction of vasoconstrictor responses to intermittent sympathetic stimulation or to injections of noradrenaline or histamine or by reduction of vascular spasms produced by continuous sympathetic stimulation or infusion of 5-hydroxytryptamine. The relative potencies of the vasodilators used against intermittent sym- pathetic stimulation, in order are: adenosine = sodium nitroprusside = CIBA 31,531-Ba [5-amino-l-(l-methylpiperid-4-yl)- 3-(pyrid-4-y1) pyrazole] > glyceryl trinitrate > papaverine = amino-phylline > dipyridamole » sodium nitrite = hydrallazine.
Effect of diazepam and chlordiazepoxide on the metabolism of other drugs
Authors: Jori A , Prestini P E , Pugliatti C
Published: April 2011

Diazepam and chlordiazepoxide, even at high single doses, do not inhibit the metabolic transformation of p-nitroanisol, aniline and aminopyrine by the 9,000 g fraction of rat liver. Although diazepam and chlordiazepoxide increase the sleeping time induced by pentobarbitone, this effect is not explained by an increase in the brain level of pentobarbitone. Repeated administrations of the two benzodiazepines increase the metabolism of p-nitroanisol, aniline, amidopyrine and shorten the sleeping time induced by pentobarbitone in rats. There was a concomitant reduction of the concentration of brain pentobarbitone.
The relation between the bactericidal activities and certain physico-chemical properties of some fluorophenols
Authors: Pinney R J , Walters V
Published: April 2011

The antibacterial activities, as demonstrated by the Rideal-Walker coefficients and viable counts, of mono-, 2,4,5– tri-, 2,3,5,6- tetra- and pentafluorophenol increase with the number of substituent fluorine atoms. The thermodynamic activities (Ferguson values) range from 0·083 to 0·022, and indicate a non-specific physical mode of action. Linear correlations occur between the equitoxic concentrations of the compounds to Escherichia coli (99·9% mortality after 50 min contact) and their molecular weights, number of fluorine substituents and water solubilities. A similar relation exists between the molar concentrations at the Rideal-Walker end points and the oleyl alcohol-water partition coefficients; no correlation occurs between toxicity and the cyclohexane-water partition coefficients. The surface tensions of equitoxic solutions vary between 57·5 and 63·2 mNm−1 (dynes/cm).
Antituberculosis activity of some nitrofuran derivatives
Authors: Bruhin H , Bühlmann X , Hook W H , Hoyle W , Orford B , Vischer W
Published: April 2011

A series of 4,6-disubstituted 2-(5-nitrofurfurylidenehydrazino)-1,3,5-triazines has been synthesized. Some of these compounds possessed good antibacterial activity against Mycobacterium tuberculosis in vitro and moderate activity in vivo (the activity in vivo was observed only with high dosages compared with compounds in clinical use and the results were also irregular). The most active compounds are triazinylhydrazones of 5-nitro-2-furaldehyde in which the triazine ring is substituted with two amino-groups, at least one of which is an (α-branched chain alkyl)- or cycloalkylamine. Structure- anti-tuberculosis activity relations for these compounds are discussed.
Quality control of white soft paraffin
Authors: Longworth A R , French J D
Published: April 2011

Samples of white soft paraffin complying with pharmacopoeial requirements vary in their physical properties. Some samples produce hard waxy lumps and permit excessive separation of liquid components (bleeding). Measurement of melting and congealing points and consistency by penetrometer failed to reveal these differences. The viscosity of samples after 20 min shear (1159s−1) is related to lump formation as detected by usual examination of samples heated and cooled without stirring and spread on a tile after gentle mixing.
Some physico-chemical properties of SKF 525-A in aqueous solution
Authors: Florence A T
Published: April 2011

The properties of solutions of SKF 525-A (β-diethylaminoethyl diphenylpropylacetate hydrochloride) have been investigated using surface tension, light scattering and microelectrophoretic techniques. The interaction of the drug with cholesterol and lecithin monolayers was studied by a surface balance method. SKF 525-A is more surface-active than chlorpromazine, and forms micelles containing 22 monomers in 0·9% NaCl solution. It increases the surface pressure of L-α-lecithin monolayers spread on water and both L-α-lecithin and cholesterol monolayers spread on 0·9% NaCl solutions at 1–2 × 10−6M concentration levels. Because of the surface-active properties of SKF 525-A caution is urged in the interpretation of enzyme inhibition results as surfactants are well known as a class to greatly affect enzyme systems.
The solubility of dodecane in water-amide mixtures
Authors: McDonald C
Published: April 2011

The solubility of dodecane has been determined in formamide, and in mixtures of water with formamide, N-methylformamide (NMF), and dimethylformamide (DMF) by a radiotracer method at 15°, 25° and 35°. The solubility of dodecane increases as the concentrations of the amides increase. The standard free energies (ΔG°), partial enthalpies (ΔH°), and standard entropies (ΔS°), of solution of dodecane have been calculated for the various systems. Positive values of ΔG° and negative values of ΔH° and ΔS° decrease numerically as the concentrations of amides increase.
The effects of P-2-AM on the release of acetylcholine from the isolated diaphragm of the rat
Authors: Goyer Robert G
Published: April 2011

Release of acetylcholine from rat isolated diaphragm preparations stimulated through the phrenic nerve was investigated in the presence of P-2-AM 0·01–100 mM. At 1 mM, the release of acetylcholine was increased by 157%, while higher concentrations resulted in a decrease. The findings indicate that the biphasic action of P-2-AM can be explained, at least in part, by variations in the quantal release of acetylcholine—an effect involving a presynaptic action.
The inhibitory effect of non-steroidal anti-inflammatory agents on aggregation of red cells in vitro
Authors: Görög P , Kovács Iren B
Published: April 2011

Aggregation of red cells of rat in saline suspension was induced by gelatin, high molecular weight dextran and fibrinogen. Except chloroquine, non-steroidal anti-inflammatory agents (NAIA) inhibited macromolecule-induced red cell aggregation in vitro. Glucocorticoids failed to inhibit red cell aggregation even in large concentrations. Of many drugs examined, only the NAIA and certain antihistamines, having experimental anti-inflammatory effects proved to be effective inhibitors of gelatin-induced red cell aggregation, in vitro.
The effect of the anion on the absorption of tetracycline from the rat stomach
Authors: Perrin J H , Vallner J J
Published: April 2011

The absorption of tetracycline from the rat stomach has been investigated at acid pH values. The absorption is dependent on the anion of the buffer and appears to be related to the surface activity of the buffer.
Evidence that the hypotensive action of methyldopa is mediated by central actions of methylnoradrenaline
Authors: HENNING M , RUBENSON A
Published: April 2011

Mean arterial blood pressure was recorded in conscious normotensive rats through indwelling arterial catheters. The effect of l-α-methyldopa (α-MD) (400 mg/kg, i.p.) was studied in animals pretreated with α-methyl-m-tyrosine (400 mg/kg i.p.) 27 and 15 h before α-MD, α-methyl-p-tyrosine methylester (H 44/68) (250 mg/kg, i.p.) 1 h before α-MD, and dl-α-hydrazino-α-methyl-β-(3,4-dihydroxyphenyl) propionic acid (MK 485, 100 mg/kg, i.p.) 30 min before α-MD. This pretreatment, which resulted in a severe depletion of endogenous catecholamines, did not alter the hypotensive effect of α-MD. The effect of α-MD (200 mg/kg, i.p.) was studied 30 min after pretreatment with the dopamine β-hydroxylase inhibitor, bis (4-methyl-l-homopiperazinyl-thiocarbonyl) disulphide (FLA-63) (25 mg/kg, i.p.). The hypotensive response to α-MD was completely abolished in these experiments. The formation of α-methylnoradrenaline from α-MD was prevented after FLA-63 but there was a significant increase in the amounts of α-methyldopamine formed.
The influence of hexobarbitone on calcium ion movements in isolated heart muscle
Authors: HAACKE H , VAN ZWIETEN P A
Published: April 2011

In beating atria (frequency 180/min) sodium hexobarbitone (7·8 × 10−4M) inhibited the rate of uptake of 45Ca2+ from the medium without influencing the total calcium content of the tissues. Concomitantly, the so-called exchangeable calcium fraction was diminished although not at equilbrium. In resting left auricles the barbiturate did not affect 45Ca+-uptake or the exchangeable calcium fraction. It seems likely that the barbiturate reduces membrane permeability towards Ca2+ during excitation without influencing the permeability at rest.
Interaction of preservatives with cetomacrogol
Authors: KAZMI S J A , MITCHELL A G
Published: April 2011

The interaction of a number of commonly used preservatives (benzoic acid, p-hydroxybenzoic acid, methyl p-hydroxybenzoate, propyl p-hydroxybenzoate and chloroxylenol with the non-ionic surfactant cetomacrogol was examined and a comparison made of various methods of expressing this interaction. It is suggested that the Scatchard equation is the most satisfactory equation for describing the binding data. Binding parameters determined from a Scatchard plot in the concentration range of free preservative appropriate for antimicrobial activity can be used to calculate the total concentration of preservative required in the surfactant system.
The effect of drugs upon the uptake of 5-hydroxytryptamine and metaraminol by human platelets
Authors: AHTEE LIISA , SAARNIVAARA LAILA
Published: April 2011

The abilities of some tricyclic and bicyclic antidepressive drugs and an α-receptor blocking agent, phenoxybenzamine, to inhibit the uptake of 5-hydroxytryptamine (5-HT) and (—)-metaraminol into human platelets have been compared in vitro. All the drugs inhibited the uptake both of 5-HT and of metaraminol into platelets. But there were differences in their abilities to inhibit the uptake of these two monoamines. The desmethylated antidepressive drugs were more potent inhibitors of metaraminol uptake than were their tertiary analogues, whereas imipramine, a tertiary amine, was by far the best inhibitor of 5-HT uptake. The order of the activities of the antidepressive drugs in inhibiting the uptake of 5-HT and metaraminol into platelets paralleled their potencies in blocking the uptake of 5-HT, and noradrenaline or metaraminol into nerve endings. It is suggested that the uptake of 5-HT and metaraminol into platelets is a useful model for the neuronal uptake of 5-HT and noradrenaline, respectively.
The effect of brocresine (NSD-1055) on the histidine decarboxylase activity in the rat gastric mucosa
Authors: MESCH H , SEWING K-FR
Published: April 2011

The effect of the histidine decarboxylase inhibitor brocresine (NSD-1055) on the specific histidine decarboxylase in the gastric mucosa was investigated in rats. The inhibiting potencies of brocresine were compared after oral and intraperitoneal administration with and without 2-deoxy-d-glucose. Furthermore, different doses of brocresine were added directly to an incubation medium containing an homogenate of the gastric mucosa of untreated animals. The gastric histidine decarboxylase of the brocresine-pretreated animals was not inhibited. Addition of brocresine to the incubation medium produced a dose dependent blockade of the enzyme. 50% inhibition was accomplished by a concentration of 1·4 times 10−6M. The results demonstrated an inhibition of the rat stomach histidine decarboxylase in vitro, but not in vivo, indicating the inability of brocresine to interfere with the biosynthesis of histamine in the rat stomach.
The effect of solvents on the potency of chlordiazepoxide, diazepam, medazepam and nitrazepam
Authors: CRANKSHAW D P , RAPER C
Published: April 2011

ED50 values for loss of righting reflex in mice have been determined for a series of benzodiazepines after intraperitoneal injection of the drugs in various vehicles. The vehicles used greatly modified the ED50 values obtained. The effects obtained were due either to a failure of the vehicle to achieve or maintain complete solubilization of the drug, or to the pharmacological action of the vehicle modifying that of the drug. Diazepam, medazepam and nitrazepam are insoluble in water, but are soluble in dimethylsulphoxide (DMSO) and in aqueous vehicles containing glycofurol or propylene glycol. Chlordiazepoxide hydrochloride is water-soluble. Similar ED50 values were obtained in experiments where the benzodiazepines were injected in an aqueous carboxymethylcellulose suspension and in experiments where the drugs were dissolved in DMSO. Lower ED50 values were obtained when the drugs were dissolved in vehicles containing propylene glycol or glycofurol. The increase in potency of the benzodiazepines could be ascribed either to the solubilization of the drugs or to the synergistic pharmacological activity of the solvents. An ED50 value for diazepam, which was not influenced by the pharmacological activity of the solvent, could be obtained using the vehicles containing either glycofurol or propylene glycol. For medazepam and nitrazepam, the solvent mixtures containing propylene glycol and glycofurol respectively were required to avoid drug-solvent interactions.