bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cell size changes during the growth of Escherichia coli partially inhibited by some antibacterial agents
Authors: Rye R M , Wiseman David 
Published: April 2011

Abstract
The effects of tetracycline, phenol, chloramphenicol and ampicillin on the rates of division and mass increase in growing cultures of Escherichia coli have been examined by comparing the number, carbon content and the size of the cells from partially inhibited cultures with those of control cultures. In cultures treated with low concentrations of tetracycline, phenol or chloramphenicol the increase in cell mass is inhibited more than cell division, thus causing a decrease in the cell size. At higher concentrations of these agents and at all concentrations of ampicillin, cell division is inhibited more than increase in cell mass so causing an increase in cell size.
The uptake of cetyltrimethylammonium bromide by Escherichia coli
Authors: Salt W G , Wiseman David 
Published: April 2011

Abstract
THE uptake of cetyltrimethylammonium bromide (CTAB) by bacteria has previously been examined by Salton (1951) and by McQuillen (1950). Both workers determined its concentration in solutions by titration with sodium cetyl sulphate using pinacyanol bromide as indicator, and reported that uptake was in the form of a typical adsorption isotherm with saturation of the cells at an uptake equivalent to several theoretical close packed monolayers.
This communication reports on studies of the uptake of 14C-labelled CTAB by cells of Escherichia coli and the concurrent release of phosphorus compounds from their metabolic pool.
Binding of crystal violet by nucleic acids of Escherichia coli
Authors: Adams E 
Published: April 2011

Abstract
The absorption isotherms of DNA and RNA from E. coli for crystal violet are sigmoid. Binding of dye was determined i) by difference in its absorbance before and after addition of nucleic acids and ii) by measuring the amount of dye dialysing through a membrane containing dye and nucleic acid. pH change caused no significant change in the degree of binding.
The anomalous chromatographic behaviour of dichlorophen and p-chlorophenol
Authors: Rapson H D C , Scartsiaris Ageliki 
Published: April 2011

Abstract
The variation of Rf value of p-chlorophenol and di-(5-chloro-2-hydroxyphenyl) methane when run alone or together on thin layer chromatograms using toluene and silica gel is attributable to adsorption rather than partition processes. This conclusion is based on a quantitative study of Rf value variation, adsorption and partition behaviour. The adsorption isotherms are used to calculate the Rf values. The latter were of similar magnitude to those obtained directly from the chromatograms.
The polarography of cephalosporin C derivatives
Authors: Jones I F , Page J E , Rhodes C T 
Published: April 2011

Abstract
WE report some preliminary measurements on the polarographic reduction of cephalosporin C, cephalothin [7-(2-thienylacetamido)-cephalosporanic acid] and cephaloridine [7-(2-thienylacetamido)-3-(1-pyridylmethyl)-3-cephem-4-carboxylic acid betaine].
Green, Page & Staniforth (1965) have shown that cephalosporin C derivatives give well-defined infrared and nuclear magnetic resonance spectra that can be used for their qualitative identification. Martin & Shaw (1965) have reviewed the application of methods such as ultraviolet spectrophotometry, paper chromatography and paper electrophoresis for cephaloridine, while Chapman, Page & others (1968) have described infrared and X-ray powder measurements for this compound. The application of mass spectroscopy to the structural elucidation of cephalosporin derivatives has been reported by Richter & Biemann (1965).
The determination of diamorphine by thin-layer chromatography and spectrophotometry
Authors: Davey Elizabeth A , Murray J B , Rogers A R 
Published: April 2011

Abstract
THE assay of diamorphine in Diamorphine Injection B.P. is based on its hydrolysis to morphine followed by a colorimetric determination (Allport & Jones, 1942; Stephens, 1951; Hooper, Shaw & Tims, 1967). Stored solutions of diamorphine may contain O3- and O6-acetyl-morphines as well as diamorphine and morphine (Davey, Murray & Rogers, 1967); all are converted into morphine in the first stage of the British Pharmacopoeial assay of the injection and thus contribute to the final morphine content.
Separation of opium alkaloids and their acetylated derivatives by thin-layer chromatography has already been reported (Mary & Brochmann-Hanssen, 1963; Vignoli, Guillot & others, 1965, 1966a, b) and the application of this technique to diamorphine, the acetylmorphines and morphine is discussed below.
Pharmaceutical applications of vapour-controlled thin-layer chromatography
Authors: De Zeeuw Rokus A 
Published: April 2011

Abstract
In thin-layer chromatography, solvent vapour plays an important role. To obtain full benefit of the influence of vapour in the technique, a new chamber has been developed, providing full vapour control over the entire plate. This allows better separations of chemically related compounds. The properties of the vapour-control chamber are shown in separations of barbiturates and local anaesthetics.
Examination of fennel fruits by gas chromatography without preliminary distillation
Authors: Betts T J 
Published: April 2011

Abstract
IT has been observed that growing fruits of fennel, Foeniculum vulgare Mill., of both the bitter (var. vulgare (Mill.) Thelung) and sweet (var. dulce) forms grown in the same garden develop approximately the same amount of anethole per 100 fruits during their maturation (Betts, 1968). Thirteen dried fennel fruits of various origins have now been examined by gas-liquid chromatography to see how the content and proportion of the essential oil constituents relate to the values previously recorded. Anethole contents differed widely, and a fennel virtually free of anethole was found. Estragole was present instead of anethole, its presence being confirmed by infrared spectroscopy. This fennel has not been reported in commerce before.
Isothermal diffusion measurement on the system water-sodium salicylate-sodium chloride at 25° at one composition
Authors: Deshmukh A , Fleming R 
Published: April 2011

Abstract
The main and cross-term diffusion coefficients for the system water-sodium-salicylate-sodium chloride have been measured at the compositon 0·05 g cc−1, and the results indicate that sodium chloride is effective in producing a flow of sodium salicylate at this concentration. Density, refractive index, partial specific volumes and gravitational data are also reported. The system has been assumed to be 3-component.
Gas-liquid chromatography of heteroyohimbine alkaloids: The effect of methoxy substitution and of configuration
Authors: Beckett A H , Dwuma-Badu D 
Published: April 2011

Abstract
The gas-liquid chromatographic retention times of heteroyohimbine alkaloids on a 1% SE-30 column are in the order pseudo &lt; epiallo &lt; allo &lt; normal. The introduction of one methoxy group into the indole nucleus doubles the retention time while two methoxy groups increase it by a factor of four. Binding of the indole nucleus reinforced by the suitably orientated lone pair electrons of the basic nitrogen to the liquid phase of the column in the important conformers of the various configurations, is used to explain the results.
The crystallization of aspirin from ethanol
Authors: Glasby J , Ridgway K 
Published: April 2011

Abstract
The rate of growth of aspirin crystals has been examined in a circulatory crystallizer in which the crystals are held in suspension as a fluidized bed. The deposition rate was measured, as a function of both the degree of supersaturation and the solution temperature, by observing the rate of weight increase and the change in particle size distribution of the crystals. The dependence of the mass transfer coefficient for the process upon the temperature was of the Arrhenius type, the activation energy being 21·8 kcal/mole. This indicates that the surface reaction step is rate-controlling, diffusional transport to the crystal surface being rapid. The density of aspirin solutions in alcohol has also been measured as a function of temperature and concentration.
An adrenergic neuron blocking action of propranolol in isolated tissues
Authors: Day M D , Owen D A A , Warren P R 
Published: April 2011

Abstract
Propranolol was tested for adrenergic neuron blocking activity in three isolated sympathetically-innervated smooth muscle preparations; the rat vas deferens, rabbit ileum and rabbit ear artery. In each preparation propranolol impaired the responses to sympathetic stimulation without reducing the responses to added noradrenaline. This blocking action of propranolol resembled that of guanethidine in time of onset and persistence of blocking activity but, unlike blocking by guanethidine, was not reversed by (+)-amphetamine. Desipramine and noradrenaline also failed to reverse the blocking action of propranolol. In the rat vas deferens preparation lignocaine had a weaker and more transient sympathetic blocking action than propranolol. It is suggested that the sympathetic blocking action of propranolol may contribute to its antihypertensive effect in man.
The metabolism of 16α-ethylprogesterone by rat liver in vitro
Authors: Stenlake J B , Templeton Richard , Taylor D C 
Published: April 2011

Abstract
The metabolism of 16α-ethylprogesterone by rat liver homogenate at different steroid to tissue ratios has been examined. The products, identified by thin-layer chromatography, gas-liquid chromatography and combined gas-liquid chromatography-mass spectrometry were 16α-ethyl-5α-pregnane-3, 20-dione and 16α-ethyl-3α-hydroxy-5α-pregnan-20-one. The yield of these metabolites was 14 and 48% respectively. The results are discussed in relation to the liver in vitro metabolism of progesterone and 16α-hydroxyprogesterone.
Protein-binding of small molecules: New gel filtration method
Authors: Cooper P F , Wood G C 
Published: April 2011

Abstract
The use of frontal analysis chromatography on Sephadex columns, previously described for protein-protein interactions (Nichol & Winzor, 1964) has been extended to the treatment of protein-small molecule interaction. Chromatograms obtained with bovine serum albumin and three different sulphonamides (sulphanilamide, sulphapyridine and sulphamethoxypyridazine) were found to conform to the theoretical patterns, and the values for the fraction of drug bound were in good agreement with those obtained by equilibrium dialysis.
A modified pressure wheel for the instrumentation of rotary tabletting machines
Authors: Deer J J , Ridgway K , Rosser P H , Shotton E 
Published: April 2011

Abstract
IN any research into tabletting processes, it is necessary to know the force applied at the punch so that the tabletting pressure may be calculated. Much work has been done using single punch machines having strain gauges bonded to the shank of the punch (Higuchi, Nelson & Busse, 1954; Shotton & Ganderton, 1960). High-speed rotary machines require additional sophistication to enable useful results to be obtained, and there are two methods known. The first is that used by Shotton, Deer & Ganderton (1963). The resistance of strain gauges near the punch tips was used to control the frequency of an oscillator, and the signal was transmitted from the rotary part of the machine to a stationary aerial by radio emission. Thus the difficulty of providing a slip ring connection to the strain gauges was circumvented. However, because the radio transmitter took up space normally occupied by punches, it was difficult to obtain readings from more than one pair of punches, and impossible to obtain readings from all. In the second method (Knoechel, Sperry & others, 1967), strain gauges were placed on the compression screws interposed between the arm holding the movable axis of the pressure wheel and the spring used to adjust the compression force applied. Deflection, measured by the strain gauges, was proportional to the force applied to the punch. Since the gauges were stationary, their output could easily be displayed on a cathode ray oscilloscope, and the pressure to each punch recorded as its head passed under the pressure wheel.
The use of diffusion theory for the assessment of mixing in a rotary coating pan
Authors: Ridgway K , Segovia E 
Published: April 2011

Abstract
The effectiveness of a coating pan in treating all the contained tablets identically depends upon its being a good mixing device; the mechanics of particle motion within such a pan are therefore of interest. One measure of the mixing rate in rotary drum mixers is the coefficient of self diffusion, a parameter difficult to measure in a coating pan. Three methods of measuring such a coefficient are reported and compared: linear sampling, total compartmenting of the bed, and high speed cinéphotography. The third method is the best, and a technique is described for treating the pictorial data to obtain quantitative results.
The anti-acetylcholinesterase activities of the alkaloids of Physostigma venenosum seeds
Authors: Robinson B , Robinson J B 
Published: April 2011

Abstract
Anti-acetylcholinesterase activities of physostigmine, physovenine, Na-norphysostigmine, geneserine and eseramine have been investigated in vitro using erythrocyte acetylcholinesterase. The former three bases show comparable activities whereas geneserine and eseramine are inactive under the same experimental conditions. The biologically active form of these bases is discussed in light of these enzyme inhibitory studies.
The dissolution of paracetamol tablets and the in vitro transfer of paracetamol with and without sorbitol
Authors: Walters V 
Published: April 2011

Abstract
MANY adjuvants such as sorbitol, glucosamine hydrochloride and sodium hexametaphosphate, have been added to oral dosage forms to improve the absorption of drugs, but Wagner (1961) emphasizes that the attribution of beneficial results to them is not always unequivocal. With sorbitol in paracetamol tablets, it has been suggested that the improved absorption is due to the sorbitol acting on the metabolism of paracetamol and as a dispersing agent (Gwilt, Robertson & others, 1963). The combination of paracetamol and sorbitol provides a readily assayable system with which to examine the role of the adjuvant.
I have examined the effect of sorbitol on the aqueous solubility and partitioning of paracetamol and have studied the dissolution rate of paracetamol from commercial tablets containing paracetamol with or without sorbitol with the aim of evaluating the effect of the adjuvant on the availability of the drug.
The influence of alkyl substitution in acids on their performance in the buccal absorption test
Authors: Beckett A H , Moffat A C 
Published: April 2011

Abstract
A method to determine the passage of acids into the buccal membrane of man is presented. The absorption is shown to be the passive entry into a lipid phase. There is an increase in absorption of the acids due to alterations in partition characteristics with increasing chain length of n-fatty acids from butyric to dodecanoic. Methyl substitution of benzoic acid increases the absorption with mono- and di-substituents, but decreases the absorption with the tri- and tetra-substituents by lowering the pKa. Predictions of the relative absorption and excretion in man of these acids is included.
Examination of the hallucinogen 2,5-dimethoxy-4-methylamphetamine
Authors: Phillips G F , Mesley R J 
Published: April 2011

Abstract
Physical characteristics are reported for a tablet form of a new hallucinogenic drug previously circulating in the USA under the name “STP”. High resolution mass, nmr, ultraviolet and infrared spectrometric evidence, which identify the extracted base as 2,5-dimethoxy-4-methylamphetamine, and its chromatographic behaviour, are compared with the experimental compound “DOM”. Polymorphic modifications exhibiting distinct solid phase infrared spectra have been studied by X-ray diffraction and by differential calorimetry. Animal behavioural tests indicate that the psychotomimetic activity of the base is comparable with mescaline but up to 50 times more potent.
Infrared identification of lysergide (LSD)
Authors: Mesley R J , EVANS W H 
Published: April 2011

Abstract
Infrared spectra of LSD and its tartrate salts, and factors affecting their reproducibility, have been investigated. Spectra corresponding to amorphous and crystalline forms of LSD base, the neutral tartrate and two forms of the hydrogen tartrate were obtained. The neutral tartrate was found to undergo conversion to the hydrogen tartrate on long standing. Comparison with spectra of related compounds shows that all the LSD spectra are distinctive and can be used for identification purposes, but the use of potassium bromide discs was found to cause spectral changes in the salts.
The flow of granular solids through circular orifices
Authors: Harwood C F , Pilpel N 
Published: April 2011

Abstract
It has been shown that the use of the bulk density term in place of the particle density, in the equation of flow for granular solids passing through a circular orifice, very largely eliminates differences due to the shape, rugosity, density, porosity and friction of the particles.
The equation
has been tested on seven different materials and has been found to predict the flow of single and binary systems with an overall accuracy of ±5% and ±10% respectively.
The effect of dimensions on the compaction properties of sodium chloride
Authors: Rees J E , Shotton E 
Published: April 2011

Abstract
Using a tablet press instrumented with strain gauges, anhydrous particulate sodium chloride was compressed to form compacts of different lengths in three dies of different diameters. For the limited range of dimensions applicable to most pharmaceutical tablets, there was a common linear relation between the applied compaction pressure and the force lost to the die wall per unit area of apparent die wall contact, during compression. Ejection forces were correlated using a similar expression. The mechanical strength of compacts was determined by diametrical compression. A relation was proposed to express the strength (Fe), of the compacts of different sizes in terms of the diametrical cross-sectional area at zero porosity (D.Lo), the relative volume (Vr) and the mean compaction pressure (Pm):
, where k and c are constants.
The effect of sodium salicylate on the binding of l-tryptophan to serum proteins
Authors: McArthur J N , Dawkins P D 
Published: April 2011

Abstract
In human serum, l-tryptophan is the only amino-acid bound to protein. Salicylate causes a release of tryptophan from its binding sites on human serum proteins and bovine albumin. Some implications of this finding are discussed.
The inhibition of human platelet 5-hydroxytryptamine uptake by tricyclic antidepressive drugs. The relation between structure and potency
Authors: TODRICK A , Tait A C 
Published: April 2011

Abstract
Thirty-five compounds related to the antidepressive drug imipramine in chemical structure have been examined for their capacity to inhibit the uptake of 5-hydroxytryptamine by human platelets in vitro. Substitution by small-sized electropositive groups in positions 2 or 3 of a benzene ring gave compounds more active than the prototype, 3-chloroimipramine being five times as potent on this test. Alteration of the characteristic seven-membered ring of the antidepressive drugs reduced the activity while substitution in the basic side-chain destroyed it. The tertiary amines were more potent inhibitors than their demethylated derivatives. In this and other ways the active structure for the inhibition of 5-ht uptake by human blood platelets differs from that for the inhibition of noradrenaline uptake by the rat heart.
On the local anaesthetic effect of barbiturates
Authors: Krupp P , Bianchi C P , Suarez-Kurtz G 
Published: April 2011

Abstract
Controversy exists about whether the free acid (non-ionized) or the anionic (ionized) form of barbiturates abolish the excitation of nerves. The experiments made showed that sodium pentobarbitone and sodium phenobarbitone are more effective at pH 6·8 than 8·8 in blocking the action potential in the desheathed frog nerve. The experimental procedure employed excludes the possibility that this difference in activity is due only to a more effective rate of penetration of the non-ionized form across the nerve membrane. In the same preparation these barbiturates at both pH 6·8 and 8·8 did not interfere with the uptake and release of radiocalcium. These data suggest that barbiturates block the action potential by increasing the surface pressure of the lipid layer of the excitable membrane and do not interfere with the calcium binding to sites which govern the increased membrane conductance during excitation.
Dopa-induced locomotor stimulation after inhibition of extracerebral decarboxylase
Authors: Bartholini G , Blum J E , Pletscher A 
Published: April 2011

Abstract
In rats, a combination of small doses of the dopa decarboxylase inhibitor Ro 4–4602 [N-(DL-seryl)-N’-(2,3,4-trihydroxybenzyl)hydrazine] with dopa causes a marked enhancement of the spontaneous locomotor activity which is not seen with dopa alone. If high instead of low doses of Ro 4–4602 are used, locomotor stimulation does not occur. Low doses of Ro 4–4602, owing to selective inhibition of extracerebral decarboxylase, enhance the dopa-induced rise of dopa and catecholamines in the brain, whereas high doses of Ro 4–4602, which also inhibit the cerebral dopa decarboxylase, increase only the level of dopa but not that of the catecholamines. It is concluded that the locomotor activation after small doses of Ro 4–4602 in combination with dopa is due to cerebral accumulation of catecholamines which consist mainly of dopamine.
The influence of ATP in brain extracts on the estimation of acetylcholine assayed on the frog rectus abdominis muscle
Authors: Stockley I H 
Published: April 2011

Abstract
Comparative studies of the sensitizing properties of creatine phosphate, ATP and a trichloroacetic acid brain extract on the acetylcholine-induced contractures of the frog rectus muscle indicate that alkaline boiling increases the sensitizations due to these substances threefold. This increase is reflected in a 25% reduction in the values for acetylcholine in brain extracts when assayed on the rectus muscle using Feldberg’s method. Since tissue extracts made with acid-alcohol, formic acid-acetone, eserine-saline and sucrose-saline also contain sensitizing substances, the acetylcholine values obtained by this assay method may be in error.
The bronchodilator action of analeptics in the guinea-pig
Authors: Lessin A W , Kramer R L 
Published: April 2011

Abstract
Picrotoxin, leptazol, nikethamide and bemegride were found to antagonize the bronchoconstrictor effects of acetyl-β-methylcholine in the guinea-pig anaesthetized with urethane. The analeptics were also active in pithed animals but not in animals that had been adrenalectomized or pretreated with propranolol. Catecholamine release from the adrenals can account for the effects observed.
Application of differential scanning calorimetry to the study of sulphathiazole crystal forms
Authors: Moustafa M A , Carless J E 
Published: April 2011

Abstract
Methods of preparation and characterization of two crystal forms of sulphathiazole using differential scanning calorimetry and infrared spectroscopy are described. Heats of transition and fusion calculated from thermal analysis are 1778±68 Cal mol−1 and 6615 ± 235 Cal mol−1 respectively. The transition temperature depends on the rate of heating and the sample source. Interconversion of the crystal forms under different conditions such as heating and suspension in water is described. An assay procedure based on the area of the thermal transition peak of Form I was devised and results of analysis of synthetic mixtures of Forms I and II are given.