bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantitative Aspects of the Sympathetic Neuro‐hormonal Control of the Heart Rate
Authors: FOLKOW BJÖRN , LÖFVING BIRGER , MELLANDER STEFAN 
Published: December 2008

Summary.In cats stimulation of the accelerans nerves exerts a much stronger effect on the heart rate than the hormones released at a similar activation of the adrenal medullas. This is in accordance with the characteristics of the sympatho‐adrenal control of other autonomic effectors.The heart response is sometimes seen to vanish quite rapidly on interruption of a low‐frequency accelerans nerve stimulation. It is therefore discussed whether the prompt reflex decreases of stroke volume, known to occur on baroceptor stimulation in man, really necessitate the assumption of a direct vagal control of the heart ventricles. It is after all not impossible that this is the consequence of an inhibition of a tonic sympathetic influence on the heart and adjacent capacity vessels, factors which both must result in some decrease of stroke volume.
Water and Food Intake and the Inhibitory Effect of Amphetamine on Drinking and Eating before and after “Prefrontal Lobotomy” in Dogs
Authors: ANDERSSON B. , LARSSON S. 
Published: December 2008

Summary.

A complete section through the forebrain through and just anterior to the orbital sulcus and directed well anterior to the caput of the caudate nucleus was not seen to primarily reduce the water intake of dogs or to cause any reduction in the amount of water drunk by the animals subsequent to the intravenous injection of a certain amount of hypertonic saline. The latter was temporarily the case in one animal where the lesion was extended in ventro‐caudal direction to involve the preoptic area on both sides.
Amphetamine (1 mg per kg of body weight) completely inhibited the drinking of water after an intravenous injection of 20 cc of a 20 % NaCl solution in 4 of 5 normal dogs tested. This was no longer the case in 3 of these animals after “prefrontal lobotomy”.
An incomplete section through the forebrain in 5 out of 8 dogs made that the dose of amphetamine necessary to inhibit, the food intake of the animals completely had to be increased by 50 to 100 %.
The Influence of Different Ions on the Intestinal Absorption of Sodium and Chloride
Authors: BUDOLFSEN SV. E. 
Published: December 2008

Summary.Previously it was found that the chloride as well as the sodium ions could be absorbed against a concentration gradient in the colon and the distal part of the small intestine of rats when pure sodium chloride solutions were infused. In this paper it is demonstrated that the chloride ion is still absorbed against a concentration gradient in the colon when sodium is replaced by potassium, calcium, magnesium or ammonium, and that sodium, too, is absorbed against a concentration gradient in the colon as well as the distal part of the small intestine when the chloride ion is replaced by acetate, nitrate, bicarbonate or sulphate ions.
The Distensibility of the Systemic Resistance Blood Vessels
Authors: FOLKOW BJöRN , LöFVING BIRGER 
Published: December 2008

Summary.Tlie distensibility of the systematic resistance blood vessels has been quantitatively measured at known levels of a steady vascular tone. Their distensibility is, from a liaemodynamc point of view. considerable except at more intense vasoconstriction where the lnmen‐to‐wall ratio is decreased enough to minimize the dietending effect of the intravascular pressure.Often, however, vascular distension is more or less balanced by adaptive changes of smooth muscle tone. Therefore. a standard pressure‐flow relationship cannot be given. as this relationship varies, not only with the region studied, but also with the level of vascular tone and reactivity.Generally, a ‘critical closing pressure’, correlated with the prevailing tone, can only be recorded if the normally occurring, adaptive changes of smooth muscle tone are eliminated. The basis for this closing is discussed at length. Reasons are presented that it might simply be an extension of the well‐known intermittent closings of the praecapillary sphincter regions to include all parallel channels at this level. It is suggested that the complete closing of this section of the vascular tree is a consequence of a pronounced distensibility of the thin intima and muscle layers of these small vessels, where an outer limit for distension is set by a surrounding network of collagen fibrils.
Functional Organization of the Dorsal Spino‐Cerebellar Tract in the Cat
Authors: LUNDBERG A. , OSCARSSON O. 
Published: December 2008

Summary.Intra‐axonal recording in Flechsig's fascieulus was used to study neurons which could be activated by electrical stimulation of group I muscle afferents. There were recorded simultaneously the mass discharge in the dissected Flechsig's fasciculus and sensory volleys with triphasic recording from dorsal roots for control of input in terms of Ia and Ib volleys. In addition adequate stimulation of stretch receptors in muscles was used in some experiments.Ib fibres reach the region of Clarke's column via the dorsal column as do the Ia fibres.Most of the mass discharge in the dissected Flechsig's fasciculus appears with a primary Ia volley but some increase occurs with Ib. Most neurons examined discharge on stimulation of Ia but some only when stimulation was raised to include part of Ib. In many neurons excited by Ia, a second post‐synaptic spike appeared with a Ib volley generated in the refractory period of the preceding Ia volley. Ia as well as Ib volleys were found to contribute inhibitory action to neurons excited by group I afferents from antagonist muscles.The discharge in secondary neurons, responding to a stretch of a muscle. was examined during contraction of the muscle (soleus. gastrocnemius or quadriceps). An acceleration was found in 36 per cent, demonstrating excitatory action by Golgi tendon organ afferents, and the remainder paused during rontraction. Occasionally results were obtained indicating convergence of excitatory action from Golgi tendon organ and muscle spindle afferents.It is concluded that some DSCT neurons subserve transmission of information from Golgi tendon organs and others from muscle spindles. The occurrence of convergence of excitatory action from muscle spindles and Golgi tendon organs is discussed.Convergence of excitatory and inhibitory actions mediated by group I afferents from the same muscle has been encountered in some cases. It is suggested that convergence of this type is exceptional and not representative for the general pattern of synaptic organization.
Potentiation of Histamine Effects by Histamine Inhibitors in the Unanaesthetized Guinea‐Pig.
Authors: WESTLING H. 
Published: December 2008

SUMMARY

Histamine was given subcutaneously to unanaesthetized guinea pigs and its effects on the respiration were studied by counting the respiratory frequency and observing the external respiratory movements.
The respiratory symptoms caused by histamine were potentiated by some histaminase in hibitors in doses, which did not increase the responses to β‐2‐pyridylethylamine, acetylcholine or carbaminoylcholine.
The specificity of the potentiation and the parallelism found between potentiating effects and histaminase inhibiting properties of the different histaminase inhibitors suggest that the increase in histamine sensitivity was due to diminished histaminase activity.
The maximum increase in sensitivity obtained by these inhibitors was about two‐fold. The skilful technical assistance given by miss M.‐B. Johansson was highly appreciated.
Electrophysiologic and Pharnincological Observations on Trypsin‐Disintegrated Embryonic Chick Hearts Cultured in Vitro.
Authors: FANGE R. , PERSSON H. , THESLEFF S. 
Published: December 2008

Summary. A suspension of living heart muscle cells has been obtained by trypsin treatment of embryonic chick hearts, and subsequently kept in tissue culture.Both discrete single cells and cell elusters were observed in the tissue culture. Histologic preparations and electrophysiologic evidence indicated that the cell clusters have a syncytial structure.The electrophysiologic properties of clusters of heart muscle cells in tissue culture have been investigated with the intracellular microelectrode technique.The values for the resting and action potentials in cell clusters are found to be of the same magnitude as those reported by other investigators in the intact embryonic chick heart.In cell clusters obtained from embryos younger than 8 days, a “prepotential” always preceded the action potential.When occasionally the spontaneous contractions of heart cell clusters temporarily stopped it was observed that oscillatory fluctuations of the membrane potential initiated the appearance of contractions.The effects of acetylcholine on the spontaneous frequency of contraction of cell clusters have been investigated. The spontaneous contractions of cell clusters deriving from the ventricular part of embryonic chick hearts were rarely (4 out of 110 clusters) inhibited by acetylcholine in a concentration of 104g/ml. The contractions of cell clusters obtained from the atrial part of the hearts were stopped to a considerable extent (115 out of 169 clusters) by this concentration of acetylcholine.
The Effects of Cooling the Feet and Closing the Eyes on Standing Equilibrium. Different Patterns of Standing Equilibrium in Young Adult Men and Women
Authors: ORMA E. J. 
Published: December 2008

Summary.A clear sex difference in behavior in standing equilibrium has been observed. Swaying in young women is significantly wider than that in young men, and the numbness of the soles due to standing in ice water and closing the eyes noticeably increases swaying in women, but not in men. This difference between the sexes and some other observations on the maintenance of standing equilibrium can be explained by the following hypothesis: If muscular strength is great, muscular myotatic stretch reflexes are used almost exclusively in the maintenance of standing equilibrium, and in this case the amplitude of swaying is small. If muscular strength is not great, other afferent parts, the soles and sight
Some Charateristics of Goldthioglucose Obesity in the Mouse
Authors: LARSSON S. , STROM L. 
Published: December 2008

Summary.1. Eating and drinking behaviour have been studied in mice made obese by injection of goldthioglucose.2. Continuous recordings of food and water intake showed that the obese mice ate less frequently but much larger average amounts of food compared to the control animals.3. It is suggested that because of damage to structures in the ventro‐medial parts of the hypothalamus in the obese mice, these animals are more dependent on the peripheral mechanisms regulating food intake, such as that referable to the gastrointestinal tract.4. The obese mice were not able to compensate with increased food intake when kaolin as caloric inert material was added to the diet.5. The control animals compensated for kaolin added to the diet by increasing the meal frequency or the amount of food eaten each time or by a combination of both.6. The obese mice showed little ability to increase their food intake when forced to exercise or when exhibiting a progressively increasing “spontaneous” activity.7. Continuous recordings of water consumption showed that no damage to the mechanisms regulating water intake was incurred in this type of obesity.
Secondary Fall in Blood Pressure Following Noradrenaline Infusion in the Cat
Authors: DUNER H. , von EULER U. S. 
Published: December 2008

Summary.The rise in blood pressure caused by an infusion of noradrenaline in the cat is frequently followed by a marked fall in blood pressure to subnormal levels, often lasting for 20–40 minutes.The sensitivity to single injections of noradrenaline is diminished during the first part of this period. After section of the buffer nerves the fall after noradrenaline infusion is prolonged and often enhanced.Intravenous infusions of calcium chloride reduce the blood pressure fall after noradrenaline.Only a brief and moderate fall is seen in animals having received TEAB in transmission blocking doses. This fall can be abolished by small doses of ergotamine.It is concluded that the fall in blood pressure after noradrenaline is partly due to a blocking effect on transmission within the vasomotor system.Certain implications of the present observations for the therapeutic use of noradrenaline infusions in man are briefly discussed.
Unsaturated Fatty Acid Composition of Subcutaneous Fat in Rats in Relation to Diet
Authors: CHRISTENSEN FREDE , DAM HENFIK , ENGEL P. FREDERIK 
Published: December 2008

Summary.The subcutaneous fat from three male rats reared on a fat‐free diet and three other male rats reared on a diet containing 28 % hydrogenated peanut oil was analyzed at regular intervals for linoleic acid and conjugated dienoic acid. The content of linoleic acid declined rapidly to a low level in both groups. The level of conjugated dienoic acid was almost constant in rats on the fat free diet, but increased to a maximum value of about 2 % in the fat of the rats receiving the hydrogenated peanut oil diet. The hydrogenated peanut oil contained less than 0.1 % conjugated dienoic acid. Thus a certain accumulation of the conjugated acid from this oil has taken place in the adipose tissue. The period in which the subcutaneous fat contains an increased amount of conjugated dienoic acid coincides with the period of growth retardation. The significance of this finding is discussed.
Studies on the Placental Transfer of Phosphate in the Guinea Pig.: I. The Transfer from Mother to Foetus
Authors: FUCHS FRITZ , FUCHS ANNA‐RIITTA 
Published: December 2008

Summary.In a study of the placental transfer of phosphorus in the guinea pig the transfer of inorganic phosphate from mother to foetus has been investigated from the 29th day to term with the aid of radioactive phosphorus. The inorganic phosphate in the maternal plasma was found to be the main source of phosphorus to the foetus. If most of the placental uptake of phosphate not needed in placental growth was considered to be transferred to the conceptus, enough inorganic phosphate is supplied to cover the foetal needs for phosphorus. hut the safety margin is small. especially late in gestation.The amount of phosphorus retained in foetal growth per day increases with advancing gestation. and the increase is linear from the 38th day to term. The amount retained in placental growth is nearly constant. during the period studied.If the maternal plasma, as our previous studies indicate, contains a labile, non‐diffusible phosphorus compound. which is broken down to inorganic phosphate in the course of the chemical determination. it is either present in too small quantities to influence the results, or it is utilized by the conceptuses to the same extent as the inorganic phosphate in the maternal plasma.The foetal plasma was found to contain twice as much inorganic phosphate as the maternal plasma. The transfer of phosphate front mother to foetus thus takes place against a concentration gradient.
Studies on the Placental Transfer of Phosphate in the Guinea Pig.: II. The Transfer from Foetus to Mother
Authors: FUCHS FRITZ , FUCHS ANNA‐RIITTA 
Published: December 2008

Summary.In a study of the placental transfer of phosphorus in the guniea pig the transfer of inorganic phosphate from foetus to mother has been investigated in the last part of gestation with the aid of radioactive phosphorus. The quantity transferred in this direction across the placenta is approximately 25 % of the amount which is transmitted from mother to foetus at the same stage of gestation. The amount transferred from mother to foetus is about equal to the amount retained in foetal growth plus the amount returned to the mother. The return of phosphate from foetus to mother is facilitated by the concentration gradient from the foetal to the maternal plasma.
Ventilatory Response to CO2 During Work at Normal and at Low Oxygen Tensions
Authors: ASMUSSEN ERLING , NIELSEN MARIUS 
Published: December 2008

Summary.The sensitivity of the respiratory center to CO2 during muscular work at normal and at low oxygen tensions has been studied in three human subjects.It was found that the rectilinear part of the stimulus‐response curves in normal air was displaced to the left of the resting curve and the more so the higher the work intensity. The steepness of the curves was in the majority of cases about the same. In low oxygen the stimulus‐response curves were displaced more to the left and were much steeper than for the same work intensity in normal air. The flattening of the stimulus‐response curves found at higher CO2 concentrations is assumed to be due mainly to a special depressant effect of high CO2 tensions on the respiratory center.
Heparin Monosulphuric Acid, β‐Heparin and Dog Mast Cell Tumour Heparin in Different Clotting Systems
Authors: MAGNUSSON STAFFAN , NILSSON INGA MARIE 
Published: December 2008

Summary.Standard ox heparin, dog mast cell tumour heparin, heparin monosulphuric acid and β‐heparin from ox lung were compared with respect to anticoagulant effect on human, bovine and dog plasma in one‐stage prothrombin, recalcification and thrombin systems, and on whole ox blood. Different values for the anti‐coagulant activity of a certain heparin was observed when using the various assay methods, which is in conformity with the results of previous authors. In addition it was demonstrated that one and the same assay method for a certain heparin may give different results depending on the species of plasma used as clotting substrate.
The Renal Excretion of Urea
Authors: BLEGEN EINAR , LYGREN TORLEIV , VOGT AUD 
Published: December 2008

Summary.Based upon works by Russian authors and upon own clearance studies the Hungarian authors Földi and Szabó in 1951 conclude that urea loading promotes tubular secretion of urea. In an attempt at reinvestigating the problem we made 18 clearance experiments in 5 dogs with altogether 87 clearance periods. Intravenous urea loads was performed in 14 experiments with 76 clearance periods. We never succeeded in raising urea clearance significantly above creatinine clearance. It is emphasized that true creatinine which shows the same values as inulin, not total chromogen determination has to be done for obtaining correct ratios.
Indirect Determination of Peripheral Blood Pressure in Mice during Light Anaesthesia
Authors: KNUDSEN PETER J. 
Published: December 2008

Summary.A method is described for measuring blood pressure in mice during light ether anaesthesia. The method involved compression of the arteria plantaris pedis with air in a glass chamber under strong illumination. During release of pressure, the pressure was arrested when blood just refilled the artery. Values at this point varied between 60‐120 mm Hg in normal mice.
A Comparative Study of Prostaglandin from Human Seminal Fluid and from Prostate Gland of Sheep
Authors: ELIASSON RUNE 
Published: December 2008

Summary.1. Prostaglandin extracted from human seminal fluid and from prostate gland of sheep have been compared chemically and biologically.2. It has not been possible to distinguish the two substances by paper chromatography, thermostability or biological tests, including rabbit jejunum, rat jejunum, guinea‐pig ileum, guinea‐pig uterus, rabbit blood pressure and cat blood pressure.This investigation has been supported by grants from the Therese and Johan Anderssons Minne, the Lars Hiertas Minne and Karolinska Institutet Stockholm.
Pyrrolidone Carboxylic Acid in Enzymatic Casein Hydrolysates
Authors: ÅQVIST STIG , WRETLIND ARVID 
Published: December 2008

Summary.An investigation has been made of the “bound” glutamic acid present in an enzymatic casein hydrolysate, aminosol, and which is determined as the difference between the values obtained micro‐biologically before and after hydrolysis of the preparation with hydrochloric acid. Part of this “bound” glutamic acid is found to consist of pyrrolidone carboxylic acid.Pyrrolidone carboxylic acid is isolated and analyzed in different casein hydrolysates, in which it is probably formed from glutamine.The pyrrolidone carboxylic acid content of the enzymatic casein hydrolysates investigated (aminosol) lies between 4.0 and 7.7 per cent.The quantity of pyrrolidone carboxylic acid in the enzymatic casein hydrolysates rises continuously during the 34‐day digestion period, and is probably formed from the glutamine freed during enzymatic digestion.In addition to pyrrolidone carboxylic acid, “bound” glutamic acid is also present in other forms in the enzymatic casein hydrolysates.
The Flicker Electroretinogram of the Human Eye
Authors: HECK J. 
Published: December 2008

Summary.An account is given of the human photopic flicker electroretinogram (ERG) with increasing flicker frequency, and its different phases are analyzed. With rising frequency, the amplitude initially diminishes owing to interference between the negative a‐wave and the 2nd positive off‐effect making the ERG practically diphasic. With a further increase in flicker frequency, a considerably greater amplitude of response is recorded, owing to superimposition of the off‐effect on the b‐wave. This is followed by a linear decrease in amplitude until fusion occurs. Slightly before fusion, the flicker ERG consists of an a‐wave and the 1st off‐effect.The flicker fusion frequency is directly proportional to the logarithm of light intensity (Ferry‐Porter law) up to 90‐95 flashes/sec. With an increase in light intensity above 2,500 lux, the flicker fusion frequency once more diminishes.The different phases in the flicker ERG are discussed. It is suggested that the splitting of the b‐wave and the off‐effect can be explained by the presence of colour components with different latency periods.
The Effect of Intracarotid Centripetal Injection of Cholinesterase Inhibitors on the Nuclear Region of the Vestibular Nerve
Authors: DIAMANT HERMAN , HEILBRONN EDITH 
Published: December 2008

Summary.Using an earlier‐described technique in which a vestibular syndrome is induced by means of intracarotid, centripetal injection of tabun the writers attempt to throw light on the question of the cause of the pharmacodynamic effect of cholinesterase inhibitors in vivo. The results show a definite relation between the induced syndrome and reduced enzyme activity. In some cases where the syndrome does not occur, there is nevertheless a definite unsymmetric decrease of the cholinesterase activity in the brain with lower activity on the injected side. It is therefore impossible to establish definitely that it is the enzyme‐inhibiting effect of the cholinesterase inhibitors which causes their pharmacodynamic effect. It may as well be a specific pharmacodynamic action. The experiments further show a rapid restitution of the enzyme activity which also occurs in brain preparations kept more than 24 hours in vitro. Determination of the activity shall accordingly be carried out within this period.
The Influence of Oxygen Tension and Some Drugs on Human Placental Vessels
Authors: NYBERG RUNE , WESTIN BJÖRN 
Published: December 2008

Summary.The response of human placentas to different oxygen tensions was studied in perfusion experiments using fresh human heparinized blood. Two different techniques of perfusion were used: constant pressure and constant output. The placental volume, the blood pressure near the afferent cannula and the flow rate through the placenta were recorded.In other experiments the circular musculature of isolated placental vessels was studied. The alterations of the length of the specimen to different oxygen tensions in the blood were registered.The tonus of the fetal placental vessels was found to be dependent on the oxygen tension of the blood. Vasoconstriction occurred when the tension was increased and vasodilatation when the oxygen tension was decreased.The response of the fetal placental circulation to some drugs was studied by means of the constant pressure perfusion technique. These experiments confirmed the findings of previous investigators.The oxygen consumption of the placenta was measured under constant flow. It was found to be 3.7±0.9 ml O2 per kg and minute.