bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the Effect of Adenosine Triphosphate on Myosin Threads.
Authors: BUCHTHAL FRITZ , DEUTSCH ADAM , KNAPPEIS G. G. , MUNCH‐PETERSEN. AGNETE 
Published: December 2008

Summary.In confirmation of Szent‐Gyorgyi et al. we find that ATP causes a strong volume constriction in myosin threads. This effect occurs in threads prepared both from enzymatically active and practically inactive myosin.Adenosine diphosphate and inosine triphosphate which release contraction in the muscle fibre, are without effect on the myosin thread.Birefringence decreases considerably during the shortening produced by ATP, while it increases when shortening is prevented.Sulfhydryl reagents reduce the changes in volume and birefringence produced by ATP in the myosin thread and also make a muscle fibre less excitable by ATP and electrical stimuli.Creatine phosphate, sodium triphosphate, sodium pyrophosphate and sodium ortophosphate, ineffective as such, likewise reduce the effect of ATP, while it is enhanced by inosine triphosphate.Previous treatment with acetylcholine reduces the effect of ATP only in enzymatically inactive dried myosin threads.Threads which show a strong shortening ability towards ATP in a tensionless condition, react with a considerable decrease in stiffness and increase in equilibrium length even at loads which in the untreated thread only produce a stretch of 0.1 per cent. Both effects are interpreted as being due to the release of a certain proportion of elastically active linkages in the minute structural elements by ATP.The work has been supported by the Michaelsen Fond, Nordisk Insulin Fond and Overretssagforer L. Zeuthens Mindelegat.
Über die Quantitative Wirkung des Pnffernervenmechanismus auf die Blutdruckauswirkungen des Adrenalins.
Authors: KUMPAS H. 
Published: December 2008

Zusammenfassung.1. Die nach der Höhe des Blutdruckausschlages im Blutdrucktest bestimmte minimale Wirkungsdosis blieb sich bei intakten Puffernerven in 3 Fällen von 16 nach Durchschneidung der Puffernerven gleich. In diesen 3 Fällen war die minimale Wirkungsdosis durch den Puffermechanismus nicht maskiert. Bei den übrigen 13 Fällen wurde die minimale Wirkungsdosis durch den Puffermechanismus maskiert. Da bei diesen Versuchen die Vagi vor Beginn der Versuche durchgeschnitten waren, rühren diese Befunde von der vaskularen Gegenregulation her.2. Die isolierte Vagotomie, bei der die Depressoren und die Sinusnerven intakt geblieben waren, übte keinerlei Einfluss auf die minimale Wirkungsdosis noch die Höhe des Blutdruckausschlages in einem anderen Dosierungsbereich aus. Wenn die Vagi zusammen mit den Depressoren durchgeschnitten wurden, die Sinusnerven aber intakt blieben, konnte man in 5 von 8 Fällen keine Vergrösserung der Blutdruckausschläge konstatieren. Bei den übrigen 3 Fällen vergrösserten sich die Blutdrucksauschläge entsprechend der Dosisgrösse, mit Ausnahme der kleinen Dosierun‐gen – bis 0.6 γ/kg, deren Blutdruckeffekte ihre frühere Höhe beibehielten.3. Die manifesten Blutdruckeffekte des Adrenalins werden betreffs ihrer Höhe von den vasodepressorischen Reflexen herabgedrückt. Bei 8 von insgesammt 12 Fällen entsprach die Vergrosserung der Blutdruckeffekte der Relation der sich auf die Höhe des Blutdruckanstieges beziehenden Effektivität der vasodepressorischen Eeflexe. Bei den rest lichen 4 Fällen gab es keine Vergrösserung der Blutdruckeffekte kleiner Dosen, doch konnte diese anlässlich grösserer Dosierungen beobachtet werden. Hier trat diese bei 8 Fällen vorhandene Relation nicht in Erscheinung. Es kann angenommen werden, dass diese Verschiedenheit davon herrührt, dass der Ausgangsblutdruck dieser Tiere unter den Versuchsbedingungen niedriger als normal war, denn em diesen 4 Fällen entsprechendes Verhalten konnte man beim gleichen Versuchstier mit niedrigerem Ausgangsblutdruck vorführen, wogegen man bei höherem Ausgangsblutdruck ein den 8 Fällen entsprechendes Verhalten konstatieren konnte.4. Die vasodepressorische Reflexfolge begann von einer gewis‐sen grösseren Dosis an schwächer zu werden um zuletzt zu verschwinden. In grossen Dosen greift das Adrenalin zerstörend in die Verrichtung der Pufferreflexmechanismen ein und es wird eine Frage der Dosierung sein, in welchem Ausmasse diese Reflexe wirksam bleiben.
The Occurrence of Citric Acid in the Human Thyroid Gland.
Authors: BROLIN S. E. , THUNBERG T. 
Published: December 2008

Summary.The investigation is based on a material of 75 thyroid glands of man which have been obtained in routine autopsies.

On the basis of this material the general occurrence of the citric acid in the human thyroid gland was established and the concentration thereof quantitatively determined. The mean value of the citric acid concentration was found to be 890 p. p. m. In the determination of this value the undeveloped and rather Ciscarce glands of subjects less than one year old have been excluded. The standard deviation is 420 p. p. m. Compared to the blood and most tissues the citric acid concentration of the human thyroid gland is remarkably high, amounting almost to 1 mg. per gram of glandular tissue.
If the gland‐material investigated is classified after the colloid content the citric acid has been found to increase greatly with the increase in the colloid content. The greater part of the citric acid is to be found in the colloid. In comparison with the colloid the concentration of citric acid in the follicular epithelium is low but otherwise no certain conclusions could be drawn. Some observations, however, suggest that the citric acid concentration in the epithelial cells may be considerably higher than in the blood.
The citric acid concentration in the thyroid gland increases greatly at first, and then more slowly up to the age of 25–30 years. After that period there is pronounced decrease, moderate and uncertain at first but gradually pronounced. With increasing age the citric acid increases again. This variation in the citric acid concentration agrees remarkably well with the structural changes of the age in question.
No variations in the citric acid concentration of the thyroid gland were shown to be primarily caused by disease. A secondary influence, however, has been observed owing to a change of the colloid content of the gland.
During the fertile ages of 15–45 years the citric acid concentration has been found identical in the two sexes. A sexual difference becomes evident, the female glands showing a considerably lower value during the subsequent 20‐year period. The probability that this difference is not accidental, has been calculated to 98.5 per cent. No corresponding difference in the structure of the thyroid gland during this period has been observed previously, and none has been evidenced in our material. No iodine determinations were carried out, but statistical calculation on the basis of data given in previous reports in the literature show no sexual differences in the age concerned.
An Electrolytical Method for the Determination of Cations.
Authors: ØRSKOV SØREN L. , RATJEN ERLING 
Published: December 2008

Summary.The method is based on the solubility in mercury of the amalgams of the cations formed by electrolysis. The amalgams are extracted by rocking movements (Widmark) AND titrated.The extraction velocity for some cations is determined.Sodium (100 per cent) and potassium (98–99 per cent) are recovered after one hours rocking. After the same time 90 per cent of calcium are extracted, some of the calcium amalgam being precipitated on the glass wall.Ammonium and guanidine are also extracted, but only slowly, magnesium and ferric ion can not be extracted.Direct determinations can be made on serum and erythrocytes, it is important that the proteins are precipitated during the electrolysis. There is good agreement with the values found after ashing of serum; direct determination on the erythrocytes give a somewhat higher value than after ashing.The analyses are carried out with 0.05 ml. serum.The applicability of the method is discussed.
Non Absorption of Finely Emulsified Paraffinum Liquidum in the Intestine of the Rat.
Authors: LUNDBÆK KNUD , MAALØE OLE 
Published: December 2008

Summary..On injection into rat duodenum of emulsions of paraffinum liquidum tenue, prepared a. m. FRAZEE, AND with an average globular diameter of 0.3–0.5 μ, no absorption was found over a period of 6 hours.It has thus been impossible to confirm this important support of the “Partition Hypothesis”.
The Concentration of Blood Lactic Acid in Man during Muscular Work in Relation to the Partial Pressure of Oxygen of the Inspired Air.
Authors: LUNDIN GUNNAR , STRÖM GUNNAR 
Published: December 2008

Summary.The concentration of blood lactic acid was studied in subjects working on a bicycle ergometer and breathing nitrogen‐oxygen mixtures with a varying percentage of oxygen, with special reference to the conditions when the work had been continued long enough to ensure the reaching of a steady state of blood lactic acid. The rise from the rest value to the steady state value was found to have a certain inverse proportional relation to the partial pressure of oxygen of the inspired gas mixture. The causes of this fact, and of the effect of acclimatisation on blood lactic acid levels during work as investigated by Edwards, are discussed.
Protein Metabolism of Tissue Cells in vitro. 5. The Accessory Growth Substances in Sugar‐free Malt Extracts.
Authors: ASTRUP TAGE , FISCHER ALBERT , øHLENSCHLAGER VILH. 
Published: December 2008

Summary.

The accessory growth substances present in barley malt extracts were purified by means of fermentation with bakers yeast, alkaline precipitation with ethyl alcohol and precipitation in glacial acetic acid with ethyl alcohol. A dry powder containing most of the activity could be prepared. The active substances in the fermented solutions are considerably more stable than previously assumed.
Using such sugar‐free preparations it was possible to show the ability of the tissue cells to utilize glucose, fructose and man‐nose for growth purposes. Without the addition of the malt extracts the sugars were inactive.

This work was aided by a grant from “Teknisk‐kemisk Fond”. The barley malt was placed at our disposal by the Carlsberg Breweries and A/S “Ferrosan”, Copenhagen, has aided us in the preparation of crude extracts.
The Effect of the Food Intake on the Morning Value of the Citric Acid Concentration of the Blood.
Authors: WALLMAN‐CARLSSON CURT 
Published: December 2008

Summary.The intake of food in the morning immediately after awakening causes an increase in the Ci‐value of the blood serum, measured by Thunberg's enzymatic method. In a series of 10 subjects the lowest increase was 5 %, the highest 32 %, and the mean value 20.6 %. When the method is used for diagnostic purposes in liver diseases, blood samples should be taken on an empty stomach and under so similar conditions as possible.
Studies on the Biochemistry of Human Semen.:Some Properties of Prostatic Phosphatase.
Authors: LUNDQUIST FRANK 
Published: December 2008

Summary.The enzymatic hydrolysis of phosphoryl choline, the natural substrate of human prostatic phosphatase, jS‐glycerophosphate and phenyl phosphate has been studied.1) The optimum pH when measured in acetate buffer solutions of constant ionic strength, is found to be about 6.0 for glycerophosphate and phenyl phosphate, and about 6.3 for phosphoryl choline.2) Fluoride, zinc chloride, oxalate and maleinate are found to inhibit the enzyme to a varying degree. Citrate to some extent abolishes this inhibition, and furthermore increases the reaction velocity of glycerophosphate and, especially, phosphoryl choline hydrolysis, also when prostatic secretion or seminal plasma is used without added inhibitor.3) The energy of activation is found to be about 11,500 cal for each of the three processes.4) The affinities between enzyme and substrate were measured at 37° and 0°. For phosphoryl choline and glycerophosphate it is about 2,500 cal/mol (37°), and for phenyl phosphate about 4,200 cal/mol. The change in heat function is small (δH = 0 ± 1,500 cal/mol).
The Influence of Some Central Nervous Depressants on the Reciprocal Inhibition Between the Two Retinae as Manifested in Retinal Rivalry.1
Authors: BÁRÁNY ERNST H. , HALLDÉN. ULF 
Published: December 2008

Summary.The influence of drugs on retina1 rivalry between a horizontal and a vertical bar was studied with the aim of finding pharmaco‐logical agents which might become useful in the treatment of suppression and amblyopia in squint,Amytal, bromural, chloral, ethyl alcohol, phenobarbital and trional can weaken or abolish retinal rivalry. Under the influence of these drugs, completely simultaneous perception of the two dis‐parate objects may occur. I n less pronounced cases only a decrease in depth of suppression of the momentarily subjugated image is observed. Together with the decrease in intensity of rivalry the drugs cause a decrease in the frequency of alternation. If, in the normal state, there is an imbalance between the two competing pictures, one of them being dominant more than half of the time, the degree of imbalance usually increases when rivalry is weakened under the influence of the drugs.Morphine in one case caused a marked increase, in two other cases uncertain decreases in rivalry. 3‐methyl‐5.5‐diphenyl‐hydan‐toin (one case) had no effect on rivalry.
Observations on the Hydrogen‐Activating Enzymes Present during the Metamorphosis of Insects
Authors: AGRELL. IVAR 
Published: December 2008

Summary.The aim of this investigation has been t o study the variation of the intermediate oxidative metabolism during insect metab‐olism as reflected in the activity of the dehydrogenase systems. Pupae and praepupoe of %he fly Calliphora erythrocephala Meig, were used and proved to be excellent experimental material for this purpose.The gas metabolism, oxygen consumption, and carbondioxide production, determined by means of the Thunberg‐microspirometer, described a U‐shaped curve during metamor‐phosis. It was shown by the application of Thunbergs' methylene blue method that the experimental animals were carriers of hydro‐gen‐activating enzyme systems. Variations in the hydrogen‐activating capacity of the dehydrogenase systems or their spon‐taneous activity are likewise U‐shaped and of the same order of magnitude as that of the gas metabolism. For this reason i t is assumed that the U‐shaped course of the respiration is, t o a cer‐tain degree, connected with variations in the activity of the de‐hydrogenase systems. There is, however, no absolute agreement between the variations in the gas metabolism and the dehydro‐genase activity. Variations in pH in the serum also give a U‐shaped curve.About 30 organic compounds have been found capable of in‐creasing the hydrogen‐activating capacity of the experimental animals in vitro. There is reason to assume that corresponding dehydrogenases are active during metamorphosis. Also inhibiting substances are observed.Changes in the hydrogen‐activating capacity due t o the ef‐fect of 16 different substances have been followed during the entire metamorphosis. The results obtained show systematic, periodically occurring variations in activity, which are considered an indication of the change in the potential activity of the respec‐tive dehydrogenase systems.The fluctuations in the potential activity seem to occur at definite time intervals and for this reason it is thought that they represent generally critical periods in the intermediary oxidative metabolism during metamorphosis.The changes in the activity of the succino dehydrogenase has been studied during the entire metamorphosis, as well as the inhibitory effect of malonate and the influence of succinate on the spontaneous activity during the same period. The results obtained give reason to assume the existence of a “succinic cycle” during the period of minimal metabolism during the metamorphosis.
On the Role of Glycollic Acid in Biological Methylation Processes
Authors: STEENSHOLT. GUNNAR 
Published: December 2008

Summary.A brief review is given of certain current ideas on the rble of glycollic acid as a methylating agent. Next the results are reported of some in vitro experiments in which guanidine acetic acid and glycollic acid or glycine, and some other substances as well, wereincubated with suspensions of various animal tissues. The de‐terminations of creatine in the reaction mixtures were carried out both by the picric acid and by the dinitro‐benzoate methods. The results were negative: in no case could any trace of a creatine synthesis be demonstrated. Finally some perfusion experiments on the excised rabbit's heart were carried out. The results were in substantial agreement with the in vitro experiments. We may therefore be justified in concluding that glycollic acid is incapable of methylating guanidine acetic acid to creatine. The relation of these results to some previous investigations by other workers is discussed.
On an Amine Oxidase in Rabbit's Liver
Authors: STEENSHOLT. GUNNAR 
Published: December 2008

Summary.The paper reports the results of an investigation of the enzyme in rabbit's liver that catalyzes the oxidation of mescaline. Another substrate for this enzyme is found. By inhibition experiments it is shown that the enzyme is in all probability structurally different from the mono amine oxidase. The experiments indicate that copper, iron, manganese and magnesium are probably of no importance for the enzymatic process. The r61e of metals is further discussed, and i t is shown that a suggestion about the nature of the mescaline oxidizing enzyme put forward by BERN‐HEIM and BERNHEIM is probably untenable.
Some Information on the Citric Acid Content of Bone Substance.
Authors: THUNBERG T. 
Published: December 2008

SummaryThe author summarizes our scant knowledge up to the present time of the citrate content of the bone system and reports new determinations carried out by him on humans, birds (Larus ridi‐bundus), fish (Clupea harengus, Gadus callarius and Scomber scombrus). The citrate determinations have been made by means of the colorimetric variation of Stahres pentabromaceton method introduced by Pucher, Shekman and Vickery, and finally with the modification worked out by Hunter and Leloir. The amount of citrate found has been put in relation to water‐free (ev. also fat‐free) substance. When expressed in this manner the value for humans, birds, and fish vary between one and a few percent. The Ci‐value in the frog, kept during the winter and not used until late in the summer, was about 0.3 %.
The Influence of Muscular Exercise on the Tolerance of Digitalis in Guinea‐Pigs.
Authors: ELMQVIST ADA , RYDIN HAKAN 
Published: December 2008

SummaryExperiments have been carried out on guinea‐pigs, which were given daily doses of digitalis subcutaneously for one month. Its effects were followed inter alia by observing the mortality among and the weight of the animals. The minimum lethal dose for intravenous digitalis administration was determined on the surviving animals according to Knaffl‐Lenz. The following results were obtained:

The animals which were immediately exposed to extra muscular exercise after the digitalis injections showed a greater digitalis tolerance than those which did not have to run (tables 1 and 2).
Under our test conditions it was possible to establish a sort of habituation of the guinea‐pigs to digitalis. The strong general effect shown by most of the animals during the first few hours immediately following on the digitalis injections in the first few days gradually subsided.
During weeks the guinea‐pigs could tolerate comparatively large doses of digitalis (half LD 50 doses twice daily). We attribute this to the low cumulative effect of digitotal, the digitalis preparation we used, and to the rapid elimination of digitalis in the guinea‐pig.
On Acclimatization in Connection with Acute Carbon Monoxide Poisonings.
Authors: GORBATOW OLEO , NORO LEO 
Published: December 2008

SummaryThe authors have exposed rats and mice daily to carbon monoxide in contents of 0.25, 0.4, 0.5 and 1 %. Their observations are as follows:— The test animals became acclimatized to carbon monoxide in contents of 0.25–0.5 % and the tolerance against CO in 8–15 days increased 2–4 times its former value. In 1 % CO only slight acclimatization was observed.— An intermission of several days in exposure diminished the tolerance. The longer the intermission was the more tolerance (got by acclimatization) the animal lost.
The Form Variations of the Spike Recorded by a Micro‐electrode Applied onto the Mammalian Retina.
Authors: GERNANDT BO 
Published: December 2008

SummaryFast recording of the spikes isolated by a micro‐electrode applied onto the cat's retina shows that, as soon as the spikes arelarge enough for ananlytical work, they are all alike though varying in size from 0.100–0.300 mV, The form of the spike is illustrated in fig. 1. It suggests that it consists of an optic nerve impulse combined with an electrotonic component from the cell bodies.
Interaction between Acetylcholine and Adenosine Triphosphate in Normal, Curarised and Denervated Muscle
Authors: BUCHTHAL FRITZ , FOLKOW BJØRN 
Published: December 2008

Summary.

Application of adenosine triphosphate (ATP) preceding the intra‐arterial injection of acetylcholine increases the sensitivity of striated amphibian and mammalian muscle to acetylcholine. This sensitization is not specifically connected with the neuromuscular transmission, for there is also in curarised muscle an increase of the mechanical response produced by electrical stimulation after previous application of ATP. This increase is, however, restricted to the actual period of contraction.
In denervated muscle intra‐arterial injection of acetylcholine renders the muscle insensitive to subsequent application of ATP. When small amounts of acetylcholine are applied, the block is only present when ATP is administered through the artery, intramuscular application of this substance still being highly effective in the release of contraction.

Larger amounts of acetylcholine also prevent intramuscularly applied ATP from being active. The electrical excitability remains unaltered.

The threshold for intra‐artefially injected acetylcholine was ound to be ten times higher in winterfrogs than in summer‐frogs. In the former acetylcholine produces a contracture‐like response. Previous application of ATP changes it to a contraction of short duration. When twitches are produced by electrical stimulation during the acetylcholine response, they are enhanced in summerfrogs and reduced in height in winterfrogs.
Intra‐arterial injection of acetylcholine decreases the electrical excitability and changes the strength‐duration curve of muscle for a considerable time after its application. The effect is especially pronounced in denervated muscle. The electrical excitability of denervated muscle is considerably higher than that of curarised muscle, while strength‐duration curves of denervated muscle are unaffected by curarisation. Previous application of ATP does not affect the strength‐duration curve of a muscle.