bluuebunny/crossref_metadata_2025 huggingface dataset:
Assay of Digitalis Preparations by the Guinea‐Pig Method
Authors: GOLDBERG. LEONARD
Published: December 2008

The guinea‐pig method for standardization of digitalis preparations (Knaffl‐Lenz 1926) has been tested with various concentrations, rates of injection and weights.

1. The lethal dose (or log lethal dose) varies proportionately to the quantity of drug injected per min and 100 g. The variations may amount to max. 44%, on an average 20%, when following Knaffl‐Lenz' original directions. When keeping standard conditions, or adjusting the lethal doses to a constant rate of injection by means of the calculated regression equation, the standard average deviation is 10—12%.

2. When determined at repealed intervals under standard conditions the guinea‐pig unit shows an average variation of 5—10%.

3. The potency of digitalis preparations should be expressed in international units or g of a standard preparation and be uniformly tested on the same stock of animals as the standard. Under these conditions the guinea‐pig unit has a stand, error of 3–5%, 5–6 animals being used for each test, and the guinea‐pig method seems to be a fairly good method of standardization.
The Blood‐Brain‐Barrier in Some Freshwater Teleosts
Authors: LUNDQUIST. FRANK
Published: December 2008

By paraneural injection of Trypanblue the presence of a blood‐brain‐barrier has been demonstrated in some common freshwater teleosts.
The Phosphate Esters Formed in the Liver Tissue of Rats and Rabbits during Assimilation of Hexoses and Glycerol.1
Authors: KJERULF‐JENSEN. K.
Published: December 2008

Phosphate esters are accumulated in the intact livers of rats and rabbits during assimilation of hexoses and glycerol, which latter was examined on rats only.

During absorption of fructose the fructose ester accumulated showed qualities similar to those of fructose‐1‐phosphoric acid; no fructose‐6‐phosphoric acid was accumulated. The amounts of fructosephosphoric acid accumulated in the liver and in the intestinal mucosa of the same rabbit seem to be equal with regard to quantity and synthetising intensity. The amounts of ester may be calculated at about 100 mgs of the ester per 100 g of liver tissue; this amount was rebuilt almost completely within 4 minutes as shown in an experiment with radioactive phosphorus.

The phosphate esters accumulated in livers of rats during absorption of glucose and galactose are probably to some extent aldose‐esters i. e. glucose‐6‐phosphoric acid (and galactose‐6‐phosphoric acid?). Some of the esters accumulated during absorption of glucose and galactose in the livers of rats and rabbits were very sensitive to acid hydrolysis and relatively resistant to hydrolysis with alkali; the possibility exists that these esters are glucose‐1‐ and galactose‐1‐esters respectively.

During absorption of glycerol an amount of glycerol representing about 100 mgs glycerol per 100 g liver tissue of rats was esterified; as phosphoglyceric acid and triosephosphoric acid could be excluded, the ester in believed to be (α‐ ?)‐glycerophosphoric acid.

No accumulation of fructose‐1‐phosphoric acid was observed in the kidneys or muscular tissue of rabbits during assimilation of fructose, but the contents of fructose‐6‐ester of the preexisting Embden‐ester was somewhat increased.
A Reticulocyte Ripening Principle
Authors: PLUM. CLAUS MUNK
Published: December 2008

When reticulocytes in vitro are suspended in physiological salt water and incubated at 40° the reticulocytes disappear only very slowly.

The rate of disappearance can be accelerated considerably by adding liver extract to the salt solution or when the reticulocytes are suspended in plasma.

The youngest and most unripe types disappear first. The disappearance thus must be due to a maturation of the reticulocytes into “adult” erythrocytes and this process must be accelerated by some unknown ripening substances found in plasma and liver extract.

The ripening process follows the monomolecular equation.

The monomolecular constant is proportional to the concentration of ripening substances in the suspending solution.

The monomolecular constant increases with increasing temperature.

When reticulocytes from the same animal are used, the monomolecular constant found at different times is the same if the same concentration of ripening substances is used in the experiments.

The monomolecular constant can vary ± 25 per cent when reticulocytes from different animals are used. The proportion between two tested solutions is, however, always the same, independent of the animals used.
Amino Acids and Tyrosine‐like Substances as Activators of the Reticulocyte Ripening Principle
Authors: JACOBSEN ERIK , PLUM. CLAUS MUNK
Published: December 2008

None of the 13 most common amino acids show any activating effect on the reticulocyte ripening principle. Only tyrosine has this effect. Investigations on some tyrosine derivatives show that the phenol group is essential to the effect of tyrosine. The phenol group must be in para position to the side chain. The amino group can be replaced by an oxo‐, an oxy‐. or a methyl‐amino group. Minor changes in the molecule not affecting the OH group give only some reduction in the activity.
A Colorimetrical Carbon‐monoxide‐hemoglobin Method of Determination for Clinical Use
Authors: PAUL KARL‐GUSTAV , THEORELL. HUGO
Published: December 2008

Carbon‐monoxide‐hemoglobin methods of determination that deal with strongly diluted blood must give too low values owing to the fact that carbon‐monoxide‐hemoglobin dissociates on dilution. A simple method, sufficiently accurate for clinical use, has been worked out from which these sources of error have been eliminated.

The determination is easy to carry out and takes only a few minutes. An important advantage of the method is that it enables determination on a micro‐scale, so that blood may be taken from the tip of the finger. Samples can be sent in capillary tubes, as for instance is done in the case of blood‐tests for alcohol according to Widmark's method.
The State of Bile Salt Solutions
Authors: MELLANDER OLOF , STENHAGEN. EINAR
Published: December 2008

The state of bile salt solutions in relation to their physiological transport function is being studied. The conductivity of sodium taurocholate is normal below 0.01 N (at 25°C), but at this concentration the conductivity curve suddenly changes its slope. The change is interpreted as being due to micelle formation. This view is supported by earlier measurements of the surface tension of sodium taurocholate solutions if these are interpreted in the light of more recent work on paraffin chain salts.

The demonstration of micelle formation in dilute solutions of bile salts together with recent solubility measurements of McBain and his collaborators is strong evidence for a “micelle solubility” mechanism for the hydrotropic action of bile salts.
Herstellung mid Eigenschaften von Substanz P
Authors: EULER. U. S. v.
Published: December 2008

Eine Methode zur Herstellung gereinigter Präparate von Substanz P aus Pferdedarm wird beschrieben. Die besten Präparate zeigten ohne weitere Reinigung eine Wirkung von 1 E. in 0.2 mg Substanz.

Die Substanz lässt sich als Pikrat ausfälien. Gereinigte. Pikrate zeigten eine beste Wirksamkeit von 1 E in 0.13 mg.

Kataphoreseversuche ergaben, dass die Substanz noch bei pH 6.4 kathodisch und bei pH 7.1 anodisch wandert.

Diese Untersuchung wurde durch Mittel der Stiftung »Therese och Johan Anderssons mine» unterstützt. Für wertvolle Hilfe spreche ich Frl. M. Nyborg und cand. med. G. Engstedt meinen besten Dank aus. A. B. Astra, Södertälje, hat gütigst Rohextrakte zur Verfügung gestellt, wofür ich hier danken möchte.
A New Method for Direct Electric Registration of the Intra‐Arterial Pressure in Man, with Examples of its Application.
Authors: BUCHTHAL FRITZ , WARBURG ERIK
Published: December 2008

A new manometer is described with electric transmission for direct mensuration of the intra‐arterial pressure in man. Its static and dynamic sensitivity is such that all the details of the course of the curve are reproduced without distortion, both as regards time and amplitude. The pressure variations act on a condenser chamber and are registered as changes of capacity.

As examples of its use experiments are described with simultaneously registrations of the intra‐arterial pressure and the electrocardiogram, and with simultaneous registrations of the pressure in the brachial and femoral arteries. Besides, the arterial pressure was measured under the effect of amyl nitrite and local occlusion distal from the point where the pressure was taken. The various components of the pressure curve, and their variations under these conditions, are discussed.
A Method for Detection and Determination of Carbon Monoxide in Coagulated Blood
Authors: WENNESLAND R.
Published: December 2008

The method of the author for detection and determination of carbon monoxide in blood is modified for analysis of coagulated blood. The volume of the blood is measured in a graduated syringe, and the clot is finely crushed by squeezing the sample out through the syringe tip. It is delivered into Erlenmeyer flasks, and carbon monoxide is liberated by adding sulfuric acid. The flasks with blood acid mixture are connected by means of an airtight rubber cuff with other flasks. which contain a known solution of palladium chloride.

The carbon monoxide passes into the palladium chloride, and a fine dark brown mirror of metallic palladium is seen after 5 to 30 minutes. The reduction of palladium chloride reaches a maximum after 3 hours when the flasks are rotated, 14 to 18 hours when they are left lying still. Excess of unreduced palladium chloride can be determined ideometrically, and the quantity of carbon monoxide present is calculated from the difference between original and excessive palladium chloride.

The method can also be applied as an approximative one for detection and rough estimation of carbon monoxide, by observing the time elapsed from the addition of the sulfuric acid until the mirror of metallic palladium is visible, and by judging the solidity of the mirror.
“Red” and “Green” Receptors in the Retina of Tropidonotus
Authors: GRANIT RAGNAR
Published: December 2008

Micro‐electrode, amplifier and cathode ray oscillograph have been used for the recording of “spikes” from restricted units in the retina of anaesthetized snakes in response to monochromatic light of known energy content. The problem has been to study the distribution of sensitivity to monochromatic light of more or less restricted discharges in this cone eye.

There is a broad dominator band of sensitivity with maximum in 0.560 μ, similar to the dominator found in the frog's eye.

There are further two narrow modulator bands of sensitivity with maxima in respectively 0.600 and 0.520 μ.

The “red” modulator is sometimes obtained in the practically isolated state but generally the “green” modulator appears coupled to it so that a secondary hump of variable size is found with maximum in 0.520 μ.
On the Amount of Reticulocyte Ripening Substances in the Plasma of Various Adult Mammals.
Authors: PLUM CLAUS MUNK
Published: December 2008

The amount of ripening substances in plasma is considerably reduced when whole blood is stored. The reduction seems to be larger, the more reticulocytes were found in the blood sample. When the blood clots about frac12; of the ripening substances disappear.

When plasma is stored only a slight decrease in the quantity of ripening substances occurs. Plasma incubated for 24 hours at 4° remains practically unchanged.

The quantity of ripening substances in the plasma of various mammals shows a certain correlation between the number of reticulocytes in the circulating blood and the concentration of the substances that determine the ripening of the reticulocytes, so that a high percentage of reticulocytes goes with a low ripening index and vice versa. This applies both from individual to individual and from species to species. In blood in which no reticulocytes are found there is the highest concentration of ripening substances. This being the case with oxen I chose to their plasma as the unit for the concentration of ripening substances.
Reticulocyte Ripening Substances in Plasma in Animals with Increased Erythropoiesis.
Authors: PLUM CLAUS MUNK
Published: December 2008

The quantity of ripening substances in young rats is large at birth and afterwards decreases with the fall in the number of reticulocytes in percentage of erythrocytes, and when figure sare reached that accord with those found in mature rats, the rest of the blood picture also resembles that in mature rats.

During chronic hemorrhagic anemia a rise in the number of reticulocytes may be seen in rabbits. The reticulocytes do not change in character as regards the time they take to ripen when they are subjected to the same concentration of ripening substances, but on the other hand an increase in the quantity of ripening substances in plasma is found in anemized rabbits. This increase shows that under the conditions here described the reticulocytes in the vascular system must ripen about 20 ‐ 30 % more rapidly than those in normal rabbits.

In the two cases investigated an increased erythropoiesis then is followed by an increased amount of reticulocytes ripening substances in the plasma.
A Note on the Preparation of Renin and the Appearance of a Heat‐Stable Pressor Substance in Renin Solutions.
Authors: EULER U. S. v. , SJÖSTRAND T.
Published: December 2008

A convenient method for the preparation of renin from pig's kidney is described.

Purification of crude renin preparations has been accomplished by fractionate precipitation with acetone or by adsorption to kaolin.

A dialysable, heat‐stable pressor substance may appear spontaneously in dialyzed renin solutions. The new substance has not the properties of hypertensin (angiotonin).
Is the Citric Acid Metabolism Affected by Ether Anaesthesia?
Authors: MÅRTENSSON JOHAN
Published: December 2008

A series of experiiiients on rabbits has shown that

1) Ether anaesthesia does not alter the citric‐acid content of the blood serum (Ci/s) in a nephrectomized animal. just as little as it does in a normal animal;

2) Ci‐elimination in a nephrectomized animal proceeds with the same intensity both before and after an ether anaesthesia;

3) After nephrectomy without anaesthesia the Ci/s rises, as it also does after nephrectomy under anaesthesia;

4) After nephrectomy without anaesthesia the elimination of administered Ci is considerably slowed up as compared with the elimination before the nephrectcmy.

The experiments show that the anaesthesia administered in the Writer's earlier animal experiments did not influence the results of the investigation, which have accordingly been confirmed.
The Spectral Properties of the Visual Receptors of the Cat
Authors: GRANIT RAGNAR
Published: December 2008

The micro‐electrode technique has been used for the recording of spikes of activity from the retina of the cat in order to study the distribution of sensitivity to spectral light of the retinal elements.

In dark‐adapted cats the distribution of sensitivity corresponds to the absorption curve for visual purple.

In light‐adapted cats some elements give the broad so‐called photopic dominator band with maximum in 0.560 μ, others a narrow curve with maximum in 0.520 μ combined with the dominator in different ratios.

The narrow curve is probably identical with the band seen in the eyes of rats and guinea pigs corresponding to an abnormally narrow absorption curve for visual purple, in the cat shifted somewhat to the right because of the added effect of the dominator.

Some results indicate that back reflexion from the tapetum lucidurn plays a ro1e in determining the shape of the curves in the yellow‐green region of the spectrum.

The colour vision of the cat has been, discussed in the light of the results arrived at.
Rate of Formation of Nucleic Acid in the Organs of the Rat.
Authors: HEVESY G. , OTTESEN J.
Published: December 2008

Labelled phosphate is administered to adult rats by subcutaneous injection. After the lapse of 4 days, the rats are killed and the desoxyribose nucleic acid present in different organs is extracted. By comparing the activity of 1 mg desoxyribose nucleic acid P with the activity of I mg cellular inorganic P of the same organ, data on the percentage renewal of the desoxyribose nucleic acid present in the organs are obtained.

In the course of 4 days, only a minor part of the desoxyribose nucleic acid present in all the organs investigated is found to be labelled, i. e. renewed. The greatest daily renewal of nucleic acid (15 per cent) takes place in the mucosa of the small intestine. This is followed by the spleen (5.8 per cent), the testes (2.6 per cent), the muscles (1.9 per cent), and the liver (1.0 percent). The lowest figures are shown by the kidneys and the brain (0.6 per cent).
Propagation of Contraction in the Isolated Striated Muscle Fibre.
Authors: BUCHTHAL FRITZ , KNAPPEIS G. G.
Published: December 2008

The propagation of contraction over the isolated muscle fibre is measured by the changes in the cross striation, i. e. shortening of the anisotropic (A) and lengthening of the isotropic (I) substance being used as indicator. Simultaneous microcinematography (100 Pictures/sec.) of two points of the isometrically placed fibre shows a phase difference in the course of the changes in cross striation, which corresponds to a propagation rate of 0.32 m/sec ±±0.016 (20° C). The change in the cross striation is transmitted through the fibre without decrement. Dependent on the distance between point of measurement and point of stimulation, an increase in height of compartment is found so long as the contraction has not reached the fibre elements under observation.

The rate of propagation of contraction is essentially lower than that of the spread of action potential (excitation potential). The influence of propagation velocity on the course of the mechanical tension developed, and on the latent period, are discussed.
The Determination of Ascorbie Acid in Biological Fluids
Authors: REHBERG P. BRANDT
Published: December 2008

Various redox‐indicators have been tried in determinations of ascorbic acid.

Dichloroindophenole seems to be best suited for electrophotometric determinations.

A simple but improved electrophotometer is described.

Methods for the determination of ascorbic acid in various biological fluids are described. In the serum the determination may be carried out without protein precipitation.

In urine substances are present, which contrary to the general conception interfere most in the more acid buffers

The best results are obtained with buffers of a pH around 4.5.
The Nature of the Amino Nitrogen of Red Corpuscles
Authors: USSING HANS H.
Published: December 2008

The permeability of red corpuscles to amino acids is examined. It is shown that monarnino monocarbonic acids diffuse until an even partition is reached in the two water phases. This process takes less than 24 hours at 37°. The dicarbonic acids: glutaniic acid and aspartic acid are diffusing extremely slowly through the corpuscle membrane. It is demonstrated that monoamino monocarbonic acids are present in about the same concentration in the corpuscles and the plasma.

The origin of the high amino‐N content of the corpuscles compared with the plasma is investigated and it is found that nearly all the excess amino‐N came from glutathione so that the concentration of true amino acids is equally high in the water phases of corpuscles and plasma.
Antithrombin Content of the Blood in Peptone Intoxication of Rabbits.
Authors: VOLKERT MOGENS
Published: December 2008

1. Experimental studies are reported on the tolerance and reaction of rabbits to intravenous injection of Witte peptone, and it is illustrated that shock can be produced also in rabbits if only the peptone is injected in sufficient amount.

2. The antithrombin content of rabbit blood is examined after injection of varying amounts of peptone. It is pointed out that, when shock is produced, it is possible also in rabbits to elicit an increased formation of heparin‐like substances in the blood. In addition, it is demonstrated that administration of smaller amounts of peptone may give a decrease in the antithrombin content of the blood. These findings are discussed.
The Reticulocyte‐Ripening Index after Loading with Liver Extract and Tyrosine
Authors: PLUM CLAUS MUNK , PLUM RUTH
Published: December 2008

After injections of liver extract in rabbits, an increase in reticulocyte‐ripening substances in plasma is found. In the first 24 hours after the injection the ripening substances in plasma can be activated with tyrosine in contrast to normal plasma and are therefore taken to be the unaltered liver substances.

Injections of tyrosine alone in the same quantities as found in the liver extract used, also produced an increase, but exclusively of fully activated ripening substances. Controls with saline give no rise.
Microdetermination by Electrolysis of the Sum of Inorganic Cations in Biological Fluids.
Authors: HOLM‐JENSEN IB.
Published: December 2008

A brief survey of the principles of electrolytic determinations of cations of alkali metals and of metals of the alkaline earths is given and a modification of the method of Adair and Keys for microestimation of the sum of cations in unashed samples of biological fluids is presented.
On the Effect of some Coumarin and Dicoumarin Derivatives on the Prothrombin Level in Babbits.
Authors: LEHMANN JÖRGEN.
Published: December 2008

The prothrombin depressing effect of derivatives of coumarin and 3,3'‐methylene‐bis‐(4‐hydroxycoumarin) have been investigated in rabbits in order to find the pharmacologically active groups and if possible a watersoluble stable compound of the dicoumarin.

Most of the substances tested were found active. The highest activity—combined with less toxicity—was excerted by 3,3'‐methylene‐bis‐(4‐hydroxycoumarin).

Carboxymethylene‐bis‐(4‐hydroxycoumarin) was water‐soluble but of very little activity.

The active groups in the dicoumarin are discussed. Introduction of certain radicales in the hydroxygroups as well as in the methylene bridge did not abolish the activity whereas this was the case when other radicales were introduced at the same places.
Oxidatire Breakdown of Hyaluronic and Chondroitin Sulphuric Acid.
Authors: SKANSE BENGT. , SUNDBLAD LARS.
Published: December 2008

The viscosity of hyaluronic acid solutions is markedly reduced by ascorbic acid in the presence of atmospheric oxygen. Cu++ highly increases this effect, which is on the other hand completely inhibited by diethyldithiocarbamate, or cyanide. Catalase does not inhibite the action of ascorbic acid.

Dehydroascorbic acid obtained by oxidation of ascorbic acid with molecular oxygen + Cu++ has, under aerobic conditions, the same effect as ascorbic acid + Cu++.

The effect of ascorbic acid is also greatly increased by hydrogen peroxide, which itself although relatively slowly, reduces the viscosity of hyaluronic acid solutions. In the presence of hydrogen peroxide the ascorbic acid is also active anaerobically. The mechanism of the action of ascorbic acid is discussed.

A viscosity decreasing effect is brought about also by molecular oxygen (at + 100° C), potassium permanganate, and, in the presence of atmospheric oxygen, by hydroquinone, pyrogallol and cysteine + Cu++. The effect of oxygen is inhibited by diethyl‐dithiocarbamate and cyanide.

The products formed from hyaluronic acid during its oxidative breakdown are non‐reducing and dialysable. The decrease of the viscosity is accompanied by the disappearance of the double refraction of flow shown by the native hyaluronic acid solution.

The oxidative depolymerisation of hyaluronic acid is connected with the formation of titratable acid groups in an amount approximately corresponding to one carboxylic group for each disaccharide unit of glucuronic acid and N‐acetylglucosamine.

Determinations of glucosamine and glucuronic acid in the solution of the dissociated products suggest that the main reaction product might be a “disaccharide” of glucuronic acid and N‐acetylglucosaminic acid.

Chondroitin sulphuric acid is broken down in the same way as hyaluronic acid by ascorbic acid and hydrogen peroxide. The reaction is, however, slower and does not proceed as far as that of hyaluronic acid under the experimental conditions employed.

Heparin, starch and cellulose could be similarly broken down to some extent by ascorbic acid.
On the Effect of Local Stimulation by Cold on the Adrenaline Secretion.
Authors: EKSTRÖM TORE. , LUNDGREN NILS. , SCHMITERLÖW CARL G.
Published: December 2008

The adrenaline secretion following on local cold‐stimulation of the skin has been studied in the rabbit. As an indication of increased adrenaline secretion, the increase in width of a sympathetically denervated pupil, sensitized by cocaine, was employed.

In animals with intact innervation of the skin the adrenaline secretion showed an increase during the cold‐stimulation, even if body temperature was kept constant. This effect was not produced after previous section of the spinal cord or after lumbar anaesthesia.

In animals in which the innervation to the cold‐stimulated skin area had been cut off, no demonstrable increase in the adrenaline secretion appeared in response to the stimulation. The effect of the cold‐stimulation on the adrenaline secretion is thus reflex in kind.

Even a considerable fall in general body temperature did not in itself provoke any detectable reflex liberation of adrenaline.
On the Glucosidases of the Intestine of the Pig.
Authors: STEENSHOLT GUNNAR. , VEIBEL STIG.
Published: December 2008

An investigation is made of the glucosidases of the small intestine and the duodenum of the pig. It is shown that both α‐and β‐glucosidase occur, and the pH‐activity curves of both enzymes are determined.
Histamine and Peptic Secretion
Authors: BJÖRKMAN G. , NORDÉN Å , UVNÄS B.
Published: December 2008

Histamine does not stimulate the peptic glands of the cat's gastric mucosa.

Histamine does not inhibit the peptic secretion evoked by electrical stimulation of the vagi.
Some Chemical Properties of the Gastric Secretory Excitant from the Pyloric Mucosa
Authors: UVNÄS BÖRJE
Published: December 2008

The gastric‐secretory excitant from the pyloric mucosa shows the following chemical porperties:—

It is soluble in water. The solubility varies with the pH.

It is insoluble in ether, acetone, benzene, and absolute and 80% ethyl alcohol.

It is stable in weak acid and alkaline solutions. It resists heating in N/10 HCl at 100° C. but is destroyed when heated in N/10 NaOH to this temperature.

It is inactivated by pepsin, trypsin (duodenal juice), and ultraviolet light.

It dialyses through cellophane.

It is precipitated by trichloracetic acid, metaphosphoric acid, NaCl, and acetone.
Humoral or Nervous Control of Respiration during Muscular Work?
Authors: ASMUSSEN ERLING , CHRISTENSEN E. HOHWÜ , NIELSEN MARIUS
Published: December 2008

The pulmonary ventilation and the oxygen intake during light to moderate work on the bicycle ergometer were determined under normal conditions and in experiments in which the circulation to the lower extremities was interrupted by means of pneumatic cuffs. The experiments showed, that although the oxygen intake could by this procedure be diminished by 20–50 pCt., the ventilation remained almost unchanged.

From these experiments it is concluded, that the increase in the excitability of the respiratory centre towards CO2, which occurs during work cannot be ascribed to substances produced in the working muscles, but must be of nervous origin.
CO2‐breathing and Output of the Heart
Authors: ASMUSSEN ERLING
Published: December 2008

On two subjects it is shown, that hyperventilation, caused by CO2‐breathing, has an increasing effect on the cardiac output if the subject lies horizontally, none, however, if the subject is tilted to an upright (60°) position. It is concluded, that the effect of CO2‐breathing on the cardiac output must be due to the mechanical forces of hyperventilation and not to a chemical action of the CO2 on the circulation, as otherwise the difference of the effect in the two positions is unexplained.

By increasing the inspiratory or exspiratory resistance artificially the negativity of the intra‐pleural pressure could be increased, respectively decreased. It was found that this had very slight and irregular effects on the cardiac output, and it is concluded, that the augmented negativity of the intra‐pleural pressure during hyperventilation cannot be the cause of the increased cardiac output.

It is discussed how the deep respirations of the hyperventilation might influence the cardiac output, and the conclusion is put forward tentatively, that this is possible if one assumes that the enlarged respiratory movements cause a pressing‐out of blood from the intra‐pulmonary (or, and from the abdominal) vessels, when these are “filled” with blood (as in the horizontal position), not, however, when they are “empty” (as in the tilted position). The conclusion is supported by experiments, in which part of the blood was shut off in the legs.
The Exchange of Ions between Cells and Extracellular Fluid: The Uptake of Potassium into the Chorion Membrane from the Hen's Egg
Authors: KROGH AUGUST
Published: December 2008

The fact that living cells both in animals and plants are generally permeable both to kations and anions makes it necessary to investigate the mechanisms by which the large differences in concentration of single ions inside and outside cells are maintained.

As a consequence of the general and free permeability for water the osmotic pressures inside and outside animal cells must be identical, and this involves the presence of at least a large fraction of the ions in the free state, because no other substances are available to reach such high concentrations.

Methods are described to study the transfer of ions between cells and extracellular fluid in isolated chorion membranes from the hens egg, to prepare ultrafiltrates from these membranes and to distribute the ions determined on cells and extracellular solution.

The chorion membranes are made up of two layers of epithelium and a loose network of primitive connective tissue cells with large extracellular spaces. Approximate measurements of numbers and dimensions of the separate cell types are presented.

It is found that prolonged washing with potassium free Tyrode solution will reduce the K+ content of the cells to about half the normal (50 millimoles), the K+ being replaced by Na+, while K+ will be absorbed by the cells from the outside solution containing at the start 15 to 3 mM K+ down to concentrations of 1 millimole or less, raising the concentration of the ultrafiltrate from the cells above 100 millimoles. Simultaneously Na+ is removed from the cells against the outside concentration of about 150 mM.

The two ions together with the undetermined anions make up a very large fraction of the total osmotic pressure of the solution in each cell.

The active transfer of ions in both directions requires energy which appears to be provided mainly by non oxidative breakdown of carbohydrate and can go on at least for some time in the absence of free oxygen.

At low temperature (3°–7°) the active transfer is reduced or abolished and the diffusion tends to equalize the concentration of each ion across the protoplasmic boundary film.

It is pointed out in the discussion that specific structures and mechanisms involving a binding of the ions of elements in the boundary film must be assumed to account for the active transfer. The mosaic membrane model proposed by Lundegårdh is discussed and it is shown that the “points” responsible for potassium uptake are probably spaced at comparatively large distances apart.

The possible mechanisms for regulating the transfer are briefly discussed.
Über eine durch Kohlenoxydhehandlung hervorgerufene qualitative Veränderung des Stoffwechsels im Froschsartorius
Authors: LINDAHL P. E. , WERNSTEDT CHR.
Published: December 2008

In Sartorius‐Muskeln von Eana temporaria, die über Nacht in Ringerlösung bei 0 Grad geschüttelt worden sind, ist RQ gleich 0.72 ± 0.017. Eine etwa einstündige Behandlung mit 20% O2 + 80% CO bewirkt nach Überführung in CO‐freies Medium eine Erhöhung des RQ auf 0.99 ± 0.028. Diese Veränderung kann nicht auf eine Milchsäurebildung während der Behandlung zurückgeführt werden (Tab. 2). Der der Veränderung des RQ zu Grunde liegende Mechanismus wird diskutiert.
The Physiological Variations in the Reaction of the Human Urine
Authors: RYBERG CARL TH.
Published: December 2008

The physiological variations in the pH of the human urine have been investigated under fixed experimental conditions. The occurence of morning alkaline tides and postprandial alkaline tides has been confirmed, and in addition it has been shown that a meal may cause a transient excretion of a urine with an increased acidity before the alkaline tide begins.
Eine Antriebsvorrichtung für Laboratoriums‐gebrauch—in Verbindung mit einem Präzisionsinjektionsapparat
Authors: LINDGREN GUNNAR
Published: December 2008

Es wixd eine Vorrichtung für Permanentinfusion beschrieben; dieselbe gestattet kontinuerliches Variieren der Injektionsge‐schwindigkeit zwischen 1 und 3 125—ohne Auswechseln der Spritze. Die Apparatur kann auseinandergenommen werden und der Motor mit dem Zahnradsystem für sich gebraucht werden und an verschiedene Laboratoriumsapparate gekuppelt werden.
Changes in Respiration when Changing to Different Postures
Authors: OWE‐LARSSON A. O.
Published: December 2008

When changing an anaesthetized rabbit from a horizontal to a head‐up position, a considerable decrease in ventilation was obtained, this being greater at 90° than at 45°. There was a decrease both in frequency and amplitude. When reverting to the horizontal position, an accelerated respiration above the normal was caused, but the normal state afterwards returned.

When changing the animal to the head‐down positions the effect was not so pronounced as in the above mentioned case. The frequency was not largely affected or increased, whereas the amplitude showed a decided decrease. Thus the former often increased the ventilation, while the latter decreased it. Ventilation decreased in general.

After the denervation of the two sinus regions, the same effect was brought about in the head‐up positions as has been described for intact animals. There seemed, however, to be a tendency to a relatively greater decrease in the amplitude than in the frequency in comparison with intact animals. There was generally speaking an increase in frequency and a decrease in amplitude in the head‐down positions.

After dividing the vagi the decrease in ventilation when changing to the head‐up positions was as great as in intact animals. The decrease was brought about by considerable decrease in amplitude. Frequency increased in both experiments. A slight increase in frequency and decrease in amplitude was obtained with, the head‐down positions.

A decrease in ventilation was obtained both before and after the denervation in an experiment on cat when changing to the head‐up position, and this, too, was usually the case with the head‐down. The decrease in amplitude played the decisive part.
Influence of Oxygen Inhalation on the Chemo‐receptor Activity of the Sinus Region in Babbits
Authors: HEJNEMAN EVERT
Published: December 2008

In rabbits oxygen inhalation seems to have the same influence on the chemoreceptor activity of the sinus region, as had been established earlier for cats and dogs; with the modification, however, that the decrease of the blood pressure in the intact animal was legs constant.
A Method for Transecting the Pituitary Stalk of the Bat
Authors: BROLIN SVEN ELOV
Published: December 2008

Investigations by various authors into the effect of transections of the pituitary stalk upon the action exercised by the pituitary gland on other organs have given varying results. This disagreement, at any rate when the rat has been used as experimental animal, seems to be partially due to the fact that no sufficiently reliable method for transecting the pituitarity stalk has been described. In the present paper a method of severing the pituitary stalk of the rat is submitted by which the stalk can be approached by the parapharyngeal route and severed under ocular control. Of nine rats operated on by this method it gave in six cases complete section and in two partial section with pars‐tuberalis cells remaining in continuity with the anterior lobe.
Altersveränderungen des Berührungssinnes: Druckpunktschwellen und Druckpunktfrequenz.
Authors: RONGE HANS
Published: December 2008

Die Altersveränderungen der Anzahl Druckpunkte und der Reizschwellen auf der volaren Seite der Handwurzel wurden studiert. Die Resultate sind folgende:

Indem man in Serien von Reizen mit einem Ästhesiometer die Anzahl Empfindungen in einem bestimmten Hautbereich bei steigenden Reizstärken bestimmt, erhält man einen Grenzwert, der die optimale, d. h. alle Druckpunktschwellen erreichende Reizstärke angibt (Tab.).

Diese optimale Reizstärke nimmt mit steigendem Alter erheblich. ab (Abb. 2). Dies erklärt sich wakrscheinlich durch eine mit dem Alter zunehmende Deformierbarkeit der Haut (Epidermis).

Die Anzahl Empfindungen bei optimaler Reizstärke ist ein Mass der Druckpunktdichte in dem Hautgebiet. Diese Werte erfahren eine bedeutende Reduktion mit steigendem Alter (Abb. 3). Während der Wachstumsjahre beruht dies in erster Linie auf der fortschreitenden Flächenvergrösserung des Körpers. In der Zeit zwischen dem Abschluss des Wachstums und dem Senium, wo die Druckpunktinvolution nach wie vor deutlich bemerkbar ist, muss die Ursache in einer fortschreitenden Involution der berührungs‐rezipierenden Nervenendigungen der Haut zu suchen sein.

Diese Druckpunktinvolution stimmt gut mit der von dem Verfasser früher beschriebenen Altersinvolution der Meissner‐schen Nervenendkörperchen in der Fingerhaut überein. Dies kann jedoch nicht als Beweis für eine berührungsrezipierende Funktion der Meissnerschen Körperchen aufgefasst werden.

Die Untersuchungsresultate schliessen nicht aus, dass die Altersinvolution der Druckpunkte ziemlich kontinuierlich während des ganzen Lebens weitergeht und also keine banale, senile Veränderung ist.
Stretch Potentials of Skeletal Muscle
Authors: BJURSTEDT K. , SOHMITERLÖW O. G.
Published: December 2008

True stretch potentials from the surface of striated injured muücle (frog's gastrocnemius and sartorius, rabbit's tibialis anterior) have been recorded.

The cause of the normal stretch potential is partly ascribed to a, lengthening of the distance between the source of demarcation E. M. F. and the leading‐off point on the uninjured surface of the muscle during the stretching.

Denervation or treatment with curare did not affect the stretch potential.

Potassium and calcium salts, as well as novocaine, were found to change the shape of the normal stretch electrogram. It is suggested that these changes are caused by depolarization phenomena in the surface of the uninjured part of the muscle.

Soaking the muscle in hypotonic Ringer's solution or washing the muscle after potassium treatment caused a reversal in the stretch potential (relative polarization).
Fasting Values of Blood Sugar, RQ, and Alveolar CO2 Tension on High and Low Carbohydrate Diet.
Authors: LUNDBÆK KNUD
Published: December 2008

On examining a number of subjects on a high carbohydrate diet (averaging 512 g carbohydrate daily) and on a low carbohydrate diet (averaging 135 g carbohydrate daily) the following results mere obtained:

Fasting blood sugar was unaffected by the diet, averaging 89 mg % on a high carbohydrate diet, 88 mg % on a low carbohydrate diet.

The RQ averaged 0.848 on the high carbohydrate diet, 0.755 on the low carbohydrate. This relation between the carbohydrate content of the diet and the fasting RQ corresponds closely to what can be inferred from the earlier literature.

The fasting alveolar CO2 tension averaged 42.1 mm on a high carbohydrate diet, 39.2 mm on a low carbohydrate diet. It is shown that there is an individual level of the CO2 tension which varies with the carbohydrate content of the diet.
On the Effect of Cyanide on the Respiration of Yeast.
Authors: ASTRUP POUL , STEENSHOLT GUNNAR
Published: December 2008

After an introductory review of the activating effects of cyanide on cell respiration described in the literature, the authors report a similar effect with yeast cells, which under certain conditions show a strong increase in oxygen uptake under the action of cyanide. The possible interpretations of the phenomenon are briefly discussed.
Experimental Studies on Kidney Function during Sulphate Diuresis 4. Investigations on the Kidney Function in Rabbits with Chronic Tubular Nephritis a. m. Frandsen.1
Authors: SCHOU PER
Published: December 2008

In rabbits with chronic tubular nephritis produced experimentally by means of potassium bichromate a. m. Frandsen sulphate diuresis experiments have been performed according to the principles previously laid down by the author (schou, 1943).

In this way very low figures for the urine‐C.index (down to 1.03) are obtained and correspondingly high figures for the Excr. %, for water (up to 97 %) and for the dissolved substances here examined, namely sulphate, urea, and glucose, expressing a virtual cessation of the reabsorption in the tubules.

For chlorine, however, the ability of reabsorption is in some degree retained.

The features characteristic of the sulphate diuresis in healthy animals thus prove to apply also when the tubules are almost quite destroyed, which fact affords support for the theory that a failing tubular function is in any case the most important factor in the mechanism of the sulphate diuresis.
Phosphate Exchange between Blood and Muscle Tissue Under the Influence of Insulin.
Authors: KJERULF‐JENSEN KAJ , LUNDSGAARD EINAR
Published: December 2008

By means of experiments on artificially perfused living hind‐limb preparations of cats the authors investigated the phosphate exchange between plasma and muscular tissue. The addition of insulin produced the familiar reduction of plasma phosphate as an indication of an immigration of phosphate ions in the musculature in excess of the emigration, but otherwise no alteration in the exchange of phosphate ions between plasma and muscles.

Both before and after the addition of insulin the quantity of phosphate ion immigrating per time unit is so slight in proportion to the simultaneously assimilated quantity of glucose that a passage of the glucose into the muscle cells in the form of hexo‐sephosphates formed from the inorganic phosphates of the plasma may be regarded as out of the question.
The Dark‐Adaptation of Mammalian Visual Receptors.
Authors: GRANIT RAGNAR
Published: December 2008

Dark‐adaptation has been followed in cats and guinea pigs by measuring the absolute threshold of single or highly restricted discharges, isolated with micro‐electrodes.

The curies obtained are of different types, as illustrated in fig. 1.

The different adaptation curves can be explained by the assumption that there are two kinds of rods converging in different proportion towards the same fibre in the optic nerve, (i) real rods and (ii) cone‐like rods with adaptive properties similar to those of cones.
On Serum Copper. II. Technique of Analysis.
Authors: NIELSEN A. LEVIN
Published: December 2008

Description is given of the author's modification of Mcfarlane's Method for determination of the copper content of blood and serum by means of diethyl‐dithiocarbamate.

Experiments show that acid ashing and trichloroacetic acid treatment give the same results.

For alkalinization the addition of ammonia in excess is unsuitable as it may be precipitated in the amyl alcohol as ammonium carbonate. In determinations on whole blood the presence of iron after ashing may cause an error which is avoided most easily by adding the thiocarbamate dissolved in a solution of pyrophosphate.
Dark Adaptation and Inhalation of Carbon Monoxide.
Authors: ABRAMSON E. , HEYMAN T.
Published: December 2008

Inhalation of carbon monoxide, producing contents of carbon monoxide haemoglobin up to 30 %, causes a diminution of dark adaptation, sometimes considerable sometimes smaller or none. It cannot be excluded that this condition may have practical significance for motorcar driving in the dark, e. g., in conjunction with dazzle when meeting.
The Cholesterol Content in Rabbit Serum
Authors: HOFFMEYER JØRGEN
Published: December 2008

The cholesterol content has hen determined in the serum of more than two hundred white land rabbits. The average value for all animals was found to be 40.8 nig per cent, the averagc value for the fernale rabbits being about 10 mg per cent higher than for male rabbitn. A report is given of experiments showing variations in the same animal froui day to day. Further the influence of different degrees of bleeding anaemia, inanition, ether narcosis and surgical operations is described.
Wirkung von Arsen auf respiratorisclier Gas‐wechsel und Blutstroni beim Mensclien.
Authors: LILJESTRAND G.
Published: December 2008

Bei drei Versuchspersonen bewirkte die tägliche Verabreichung von 3 mg Arsentrioxyd im Laufe von 23–29 Tagen keine Änderung des respiratorischen Gaswechsels und auch keine sichere Änderung des Herzminutenvolumens. Dagegen trat eine kleine Erhöhung der Pulsfrequenz während Ruhebedingungen ein.
On the Chemical Nature of the Thermolabile Fraction of the Reticulocyte Ripening Principle.
Authors: JACOBSEN ERIK
Published: December 2008

Some attempts to isolate the thermolabile fraction of the reti‐culocyte ripening principle from dessicated hog stomach are described.

This gastric factor is found dialysable and when purified very little soluble in water. It is very labile. The factor can be divided into two fractions, one soluble and one insoluble in methanol. The strongest preparation from dessiccated hog stomach contains 75 % xanthine which can be isolated from the gastrix extract.

Pure synthetic xanthine has a slight ripening effect. Hypo‐xanthine, 3‐methylxanthine, 4‐amino 5 formylamino 2–6 dio‐xypyrimidine, alloxan and alloxanthine have the same effect. Little or no effect have guanine, uric acid, theobromine, theo‐phylline, coffeine, 4‐amino 2–6 dioxypyrimidine, 4–5 diamino 2–6 dioxypyrimidine and barbituric acid.

When xanthine is heated dry the ripening effect is not altered, but when heated in water, the effect disappears to reappear after standing.
On the Peptidase Activity in Papain Preparations.
Authors: ÅGREN GUNNAR
Published: December 2008

It has been demonstrated that papain preparations contain an aminopolypeptidase with a substrate specificity of the same type as that of the corresponding enzyme present in the hogs pyloric and duodenal mucosa. Based on recent experimental evidence the view is advanced that the intrinsic factor of Castle may occur in certain vegetable material.

The writer is indebted to the Johan and Therese Andeisson's Memorial Fund and the Ferrosan Corporation for their grants which supported the present investigation. He further acknowledges his thanks to Miss Ahlquist for her valuable assistance throughout the investigation.
Experimental
Authors: Hakon Lund
Published: December 2008

The affinity of pancreas lipase for triacetin, tripropionin, tri‐butyrin, trivalerin and tricaproin has been investigated in homogeneous solution without activators and in the presence of bile salts, calcium chloride and egg albumin.

The solubilities in water at 30°C were determined for the triglycerides examined.

The initial velocity of hydrolysis varied directly as the enzyme concentration.

The initial velocities were directly proportional to substrate concentration in the systems without and with activators. The affinity of pancreas lipase for the triglycerides in homogeneous solution thus being extremely low.

The relative initial velocities for the hydrolysis of five triglycerides in homogeneous solution by pancreas lipase are given.
A Method for Qimntitative Determination of Acetylcholine Precursor and Free Acetyl‐choline in Tissues.
Authors: ABDON N.‐O. , LJUNGDAHL‐ÖSTBERG KARIN
Published: December 2008

A method for determination of acetylcholine precursor, free acetylcholine, and choline in tissues is described.