Showing papers by "Uppsala University published in 1968"

Pulse and respiratory grouping of sympathetic impulses in human muscle-nerves.

Abstract: A characteristic type of spontaneous activity consisting of grouped discharges of impulses was detected when recording with a tungsten semi-microelectrode from peripheral nerve bundles innervating human skeletal muscles. An analysis of this phenomenon shows that the grouped discharges are due to volleys of impulses in efferent nerve fibres which are not skeletomotor. Some findings suggest that the efferent conduction velocity is very low (about 1 m/sec). The bursts were often “pulse-synchronous” and they tended to appear periodically during certain phases of the respiratory cycle. They were not accompanied by any significant changes in the intensity of the afferent responses to phasic or sustained muscle stretch. In some experiments, repeated noxious stimuli triggered showers of impulses in the muscle nerves, similar to the spontaneous bursts. The findings lead to the conclusion that the phenomenon is due to rhythmic outbursts of impulses in sympathetic nerve fibres.

Virus-Receptor Interaction in an Adenovirus System

Abstract: HeLa or KB cells each contain around 104 receptor sites for adenovirus type 2. These are inactivated by treatment of live cells with subtilisin. The receptor activity of the enzyme-treated cells is regained after 4 to 8 hr of incubation in complete medium. A technique that utilizes the difference in buoyant density between free virus and virus-receptor complex was developed to demonstrate receptor activity. Cellular fractionation revealed that receptors were confined mainly to the plasma membrane fraction and that negligible receptor activity could be demonstrated in enzyme-treated cells. Subtilisin probably did not penetrate the cell membrane; thus, the receptors are limited to the cell surface. Purified fiber of the virion completely prevents attachment of adenovirus types 2 and 5 to receptor sites at a ratio of 105 protein molecules per cell. Adsorption studies indicate that 105 to 106 receptor sites are available for the structural protein. The fiber does not affect attachment of poliovirus type 1.

Studies in perturbation theory XIII. Treatment of constants of motion in resolvent method, partitioning technique, and perturbation theory

Abstract: After a brief survey of some basic concepts in the theory of linear spaces, the eigenvalue problem is formulated in the resolvent technique based on the introduction of a reference function φ and a complex variable ℰ This leads to a series of fundamental concepts including the trial wave function, the inhomogeneous equation, and finally the transition and expectation values of the Hamiltonian, of which the former renders a “bracketing function” for the energy In order to avoid the explicit limiting procedures in this approach, the eigenvalue problem is then reformulated in terms of the partitioning technique which, in turn, leads to a closed form of infinite-order perturbation theory The eigenvalue problem is greatly simplified if the Hamiltonian H has a constant of motion Λ or has symmetry properties characterized by the group G = {g}, and the question is now how these simplifications can be incorporated into the partitioning technique and into perturbation theory In both cases, there exists a set of projection operators {Qk} which lead to a splitting of the Hilbert space into subspaces which have virtually nothing to do with each other It is shown that, in the partitioning technique, it is sufficient to consider one of these subspaces at a time, and the results are then generalized to perturbation theory It turns out that the finite-order expansions are no longer unique, and the commutation rules connecting the various forms are derived The infinite-order results are finally presented in such a form that they are later suitable for the evaluation of upper and lower bounds to the energy eigenvalues Le probleme de valeurs propres est formule dans une methode de la resolvante, basee sur une fonction de reference φ, et une variable complexe ℰ Ceci mene a un nombre de concepts fondamentaux tels que la fonction d'onde d'essai, l'equation inhomogene et les valeurs moyennes et “de transition” de l'Hamiltonien, d'ou l'on definit une “bracketing function” pour l'energie Pour eviter les procedes explicites pour tendre a la limite le probleme de valeurs propres est reformule dans le cadre de la methode de “partitioning”, ce qui mene a une “forme fermee” de la theorie des perturbations d'ordre infini Le problkme de valeurs propres est considerablement simplifie si 1′Hamiltonien H possede une constante du mouvement Λ ou des proprietes de symetrie caracterisees par le groupe G = {g} On pose alors le probleme d'incorporer ces simplifications dans la mkthode de “partitioning” et dans la theorie des perturbations Dans les deux cas il existe un ensemble de projecteurs {Qk}, qui entrainent une division de l'espace d'Hilbert en sous-espaces mutuellement exclusifs On demontre, que dans la methode de “partitioning”, il suffit de considerer un de ces sous-espaces a la fois, et les resultats sont ensuite, generalises a la theorie des perturbations II resulte que les developpements d'ordre fini ne sont pas uniques; on obtient des regles de commutation qui relient les formes differentes Les resultats d'ordre infini sont mis dans une forme qui est propre pour le calcul de bornes inferieures et superieures des valeurs propres de l'energie Das Eigenwertproblem wurde in der Sprache einer Resolventenmethode formuliert, die auf einer Referenzfunktion φ, und einem komplexen Veranderlichen ℰ basiert ist Dieses fuhrt zu einer Reihe von fundamentalen Begriffen wie die Vergleichswellenfunktion, die inhomogene Gleichung und die Mittel- und “Ubergangs”-werte des Hamiltonoperators, welche zu einer “bracketing function” fur die Energie fuhren Urn explizite Grenzuber-gange zu vermeiden, wurde dann das Eigenwertproblem in der Sprache der “partitioning”-Methode formuliert, was zu einer geschlossenen Form fur die Storungstheorie unendlicher Ordnung fuhrt Das Eigenwertproblem kann ansehnlich vereinfacht werden, wenn der Hamilton-operator eine Bewegungskonstante Λ oder Symmetrie-eigenschaften, die von der Gruppe G = {g} charakterisiert sind, hat Die Frage ist nun wie diese Vereinfachungen in der “Partitioning”-Methode und in der Storungstheorie aufgenommen werden konnen In beiden Fallen existiert ein Satz von Projektionsoperatoren { Qk}, welche zu einer Spaltung des Hilbertraumes in Unterraume fuhrt Es wurde gezeigt, dass es in der “Partitioning”-Methode hinreichend ist, einen dieser Unterraume zunachst zu betrachten; die Resultate wurden dann zur Storungstheorie verallgemeinert Es zeigt sich, dass die Entwicklungen endlicher Ordnung nicht einmalig sind; Kommutatorrelationen, die die verschiedene Formen verbinden, wurden hergeleitet Die Resultate unendlicher Ordnung wurden in einer Form gegeben, die fur die Berechnung oberer und unterer Grenzen der Energie-eigenwerte geeignet sind

Development of the obese-hyperglycaemic syndrome in mice.

Abstract: Mice with the recessively inherited, obese-hyperglycaemic syndrome were studied at different stages of their development. Homozygous carriers of the syndrome already exhibited an excessive accumulation of fat resulting in overweight at an age of 26 days. A few days later the concentration of serum immunoreactive insulin was raised and then continuously increased until about 6 months of age. Subsequently there was a gradual decline to the levels observed in the lean litter mates. Serum glucose values above those of the lean controls were first observed at about 1 month of age. There was a subsequent increase of the blood sugar values until the mice were 3 months old, when the mean value was above 300 mg per 100 ml. The level then decreased until in 7 months old obese mice it did not differ from that in the lean litter mates. The concentration of serum free fatty acids of the obese mice was not significantly different from that of their lean litter mates; a decrease with age being observed for both types. In the old obese mice there was a fall also in the body weight to approximately normal levels. — Administration of insulin to the genetically future-obese mice displayed a higher insulin tolerance as reflected in a slower decrease of the blood sugar level at an age of 27 days. The ability of these mice to resist insulin-induced convulsions was tried as a method for an early identification of individual future-obese mice. It was, however, not possible to classify the mice completely into two genetically different groups at 23–25 days of age, although this test turned out to be fairly reliable. Glucose tolerance tests at the same early age were also found to be less useful. Only in 4 months old, obese-hyperglycaemic mice did an intraperitoneal glucose load result in a slower return of the blood sugar level to the pre-injection value. — The present findings indicate a triphasic development of the obese-hyperglycaemic syndrome. After an initial asymptomatic period lasting for the first 23–26 days of life, the various manifestations of the syndrome appear in the course of a few days. The subsequent period is characterized by increasing serum glucose and insulin concentrations and coincides approximately with the time of rapid gain in body weight. After the body growth ceases the abnormalities associated with the syndrome gradually disappear. The pattern of development of the syndrome is compatible with the view that diabetogenic factors are active during a limited period early in the life of the homozygous mice.

Calculations on the 2 S Ground State of the Lithium Atom Using Wave Functions of Hylleraas Type

Abstract: A wave function was obtained for the $^{2}S$ ground state of the lithium atom using 60 basis functions of the Hylleraas type, i.e., with interelectronic distance coordinates. The energy obtained was -7.478025 atomic units as compared with the value -7.478069 calculated from experiments. The wave function was used to calculate the Fermi contact term. It was found that this basis set gave the value 2.906, which is in agreement with experiments, when both doublet spin functions were used, but a value that was 4% greater when only one spin function was used. In the first case, 100, and in the latter, 60, linear parameters were varied. The interelectronic distance coordinates are expanded according to a formula by Sack. The final integrals are evaluated analytically, and the resulting formulas, along with a short discussion of their convergence properties, are given in an Appendix.

Capillary permeability to and extravascular dynamics of myoglobin, albumin and gammaglobulin in the uvea.

Abstract: The dynamics of myoglobin, albumin and gammaglobulin in the tissue fluids of the rabbit eye were studied in two-isotope experiments to elucidate the mechanisms for transcapillary movement of protein and protein drainage from the eye, the nature of the blood-aqueous barrier and the way in which extravascular protein may influence the formation of aqueous humor.The permeability of the blood vessels of the choroid and the ciliary processes to myoglobin was 10 to 15 times higher than that to albumin which was about twice that to gammaglobulin.In the tissue fluid of the ciliary processes the turnover rate constant for myoglobin was 25 per cent/min, for albumin it was 3.9 per cent/min and for gammaglobulin 1.6 per cent/min.The extravascular albumin spaces in the ciliary processes and the choroid were 158 μl/g and 165 μ/g respectively.The extravascular albumin spaces were 68 and 57 per cent of the myoglobin spaces in the ciliary processes and the choroid, respectively.The extravascular gammaglobulin spaces were 87, 98 and 117 per cent of the extravascular albumin spaces in the choroid, the ciliary processes and the rest of the anterior uvea, respectively.The methods employed will give new information about the dynamics of the tissue fluids also in tissues with lymph vessels.

Histochemical demonstration of carbonic anhydrase activity in some epithelia noted for active transport.

Abstract: An improved histochemical method for demonstration of carbonic anhydrase has been applied to a number of epithelia engaged in electrolyte transport. Heavy staining was found close to or in the following regions: 1 Intercellular spaces bordered with folded epithelial membranes (unpigmented epithelium of rabbit ciliary processes, straight segment of human eccrine sweat gland duct, rabbit gall-bladder and villi of rat duodenum). 2 Basal membrane infoldings (rat proximal and distal tubules, pigmented epithelium of rabbit ciliary processes). 3 Intracellular canaliculi (parietal cells of rat stomach). 4 Brush border of rat proximal tubule. 5 Certain nuclei, but only in fixed sections and of dubious specificity. Moderate to weak staining was seen in several other places in the epithelial layers.

Characteristics of Economic Sanctions

Abstract: This is Peter Wallensteen’s first academic publication (1968), and it is also the first systematic, statistical treatment of economic sanctions and their ability in achieving compliance. By selecting ten comparable cases, identifying around fifty possible explanations of the outcomes and exposing them to a statistical test, Wallensteen is able to point to a few crucial variables that can serve as a guide for the efficacy of this non-military instrument in achieving change.

Subfragments from the Fc fragment of human immunoglobulin G. Isolation and physicochemical characterization

Abstract: A fragment termed fragment Fc′ and a related fragment termed fragment pFc′ produced by the actions of papain and pepsin respectively on human immunoglobulin G have been isolated and characterized. Amino acid analyses and experiments utilizing cyanogen bromide to cleave the methionyl bonds of the Fc′ and pFc′ fragments make it possible to locate both fragments within the known chain structure of the immunoglobulin G molecule. The pFc′ fragment is probably a non-covalently linked dimer situated at the C-terminal end of the molecule, containing about 232 amino acid residues and having a molecular weight of 26000. The Fc′ fragment is a similar dimer of about 182 residues extending from near residue 14 to near residue 105 (numbered from the C-terminal end) of the γ-chain and has a molecular weight of 21000.

Visible Distances and Safe Approach Speeds for Night Driving

Abstract: The purpose of this investigation was to demonstrate the visible distances that can be considered realistic during night driving on non-illuminated roads. From the experimental data the approach speeds were calculated that can be considered as safe for various conditions and states of the driver, the car and the road. 413 drivers volunteered to participate in their own oars in 14 different places in Sweden. Each driver's task was to drive his ear towards a stationary car, both cars with dipped headlights, and to brake as soon as he was aware of a dark-clothed dummy that was placed in the middle of the lane beside the stationary car. A special experiment compared the results of this semi-dynamic test with those of a fully dynamic test. The median visible distance was 23 m and the 10th percentile 15 m. The calculated safe approach speeds for the tested drivers varied between 25 km/ h and 50 km/ h depending on the conditions chosen. A simplified parallel investigation with 974 participating drivers ...

Posthypertonic hemolysis in sodium chloride systems.

Abstract: Human erythrocytes were exposed in vitro to hypertonic NaCl solutions and then to near isotonic media. The resulting posthypertonic hemolysis was studied as a function of hypertonic concentration and of time in the hypertonic medium. Providing that a critical concentration level (∼1.5 M NaCl) is exceeded, posthypertonic hemolysis is proportional both to the duration of exposure to hypertonicity and to the hypertonic concentration. The results have been interpreted in terms of a hypothesis put forward by Soderstrom (1944), who postulated that influx of salt occurred during the hypertonic phase and that a later reduction of the external concentration caused osmotic hemolysis. A rough calculation suggests that only above an external concentration of 0.65 M NaCl will an influx of salt occur. An analysis of the results in terms of this hypothesis suggested that the permeability of the cells to NaCl increases with increasing external NaCl concentration: The permeability increase was very great in the region of 3 M NaCl. The counter-current multiplier mechanism for kidney function has been criticised on the ground that red cells may not tolerate the tonicity changes postulated to exist in the kidney. In vitro experiments using slightly worse conditions than are believed to exist in the human kidney showed no significant hemolysis.

The glycosaminoglycans of dog compact bone and epiphyseal cartilage in the normal state and in experimental hyperparathyroidism

Abstract: In normal dogs and in dogs treated with 20 or 30 U.S.P. parathyroid extract for 5 and 3–4 days, respectively, the glycosaminoglycans of compact bone tissue were identified using the cetylpyridinium chloride precipitation method, and the concentrations of total hexosamines and the hexosamines corresponding to cetylpyridinium chloride precipitable acid glycosaminoglycans were determined. Further, the glycosaminoglycan pattern of the epiphyseal plate and the incorporation of35S-sulphate into the glycosaminoglycans of bone tissue and epiphyseal cartilage after administration of35S-sulphatein vivo was studied. In compact bone tissue, the hexosamines corresponding to acid glycosaminoglycans constuted approximately one third of the total hexosamine concentration and approximately 0.05–0.06% of the total dry weight. The main component of the acid glycosaminoglycans in bone was chondroitin-4-sulphate. This was sulphated to a higher degree and also of a higher molecular weight than thechondroitin sulphate of the epiphyseal cartilage, which in accordance with earlier investigations was found to have infrared characteristics of both chondroitin-4-sulphate and chondroitin-6-sulphate, with the former dominating. The molecular weights of the main part of bone chondroitin sulphate ranged from approximately 45,000 to 56,000. A small component of the bone glycosaminoglycans was hyaluronic acid. Large regularly recurring differences in the specific activity of fractions with differences in molecular weight in the condroitin sulphate of bone tissue and epiphyseal cartilage were noted. Treatment of the dogs with parathyroid extract gave no effect on the molecular weights of the chondroitin sulphate of the bone matrix or of the epiphyseal cartilage. Nor was there any unequivocal effect on the concentrations of total hexosamines or on the acid glycosaminoglycans. No evident stimulatory or depressant effect on the incorporation of35S-sulphate into the chondroitin sulphate or in the molecular distribution of newly sulphated and/or synthesized molecules of the condroitin sulphate within these tissues occurd.

Perceived rotary motion from changes in a straight line

Abstract: The problem dealth with was how perception of a three-dimensional space is related to the corresponding two-dimensional retinal image. The stimulation used was a straight line changing length and direction. For this stimulation a geometrical model was developed. The basic decoding principle in this model is that the changes in the two-dimensional figure will be perceived as three-dimensional motions of an object with constant shape and size. This principle was approximately verified for the majority of the data. The main deviation from the model was that there was generally less perceived depth than predicted. Also a second decoding principle was generally verified: rotary, but not translator motion is perceived from this kind of stimulation. A third unexpected decoding principle was found in the data: the line is perceived in a frontal-parallel direction when it has its maximal extention.

Studies on the epiphysial growth zone

Abstract: Rats were injected with35S-sulphate and killed after 24 hours. Frozen sections of the epiphysial plates were prepared, and the radioactivity in the sections was determined. They were then treated with a number of histotechnical procedures used to prepare tissues for electron microscopy. After each step in these procedures the radioactivity of the sections was again determined. From earlier investigations it was concluded that the incorporation of35S in the tissue investigated represented sulphated glycosaminoglycans. In the epiphysial plate chondroitin sulphate and possibly small amounts of keratan sulphate were found.

Upper and lower bounds to polarizabilities and van der Waals forces I. General theory

Abstract: Upper and lower bounds to polarizabilities, and long-range interactions of atoms and molecules are derived using operator inequalities. The formulae for the dispersion and the three-body non-additive forces are given in terms of the S(k), related by sum rules to properties of the separated systems. Some known approximations are obtained but with additional information about their nature, as well as several new inequalities. Their interest is that they give explicit and rigorous bounds involving quantities available from experimental data. Des bornes superieures et inferieures pour les polarisabilites et pour les interactions a longue distance des atomes et des molecules sont deduites en usant des inegalites pour operateurs. Les formules pour les forces de dispersion et les forces non-additives a trois corps, sont donnees en termes des S(k) rapportes, par regles de somme, avec des proprietes des systemes separes. Quelques approximations deja connues sont obtenues, mais avec information additionelle sur leur nature, ainsi que plusieurs inegalites nouvelles. Leur interět est qu'elles donnent des bornes explicites et rigoureuses renfermant des quantites accessibles a partir des donnees experimentales. Obere und untere Grenzen fur die Polarisierbarkeiten und fur die “long-range” Wechselwirkungen zwischen Atomen und Molekulen wurden mittels Operatorungleichungen hergeleitet. Die Formeln fur die Dispersionskrafte und die nichtadditiven Dreikorperkrafte sind in den S(k), die durch Summenregeln mit den Eigenschaften der getrennten Systeme in Verbindung stehen, ausgedruckt. Einige schon bekannte Annaherungen wurden erhalten, aber mit zusatzlicher Information uber ihre Beschaffenheit. Mehrere neuen Ungleichungen wurden hergeleitet, die explizite und strenge Grenzen geben, welche in solchen Grossen ausgedruckt sind, die aus experimentellen Tatsachen berechnet werden konnen.

STUDIES ON ERYTHRO‐KINETICS IN INFANCY:XIII. The mean Life Span and the Life Span Frequency Function of Red Blood Cells Formed during Foetal Life

Abstract: Summary Equations were developed for the relation between the production rate, the life span frequency function and the number of circulating erythrocytes and for the relation between the production rate, the life span frequency function and the relative number of circulating cells after random labelling. With the help of explicit expressions for the production rate and the life span frequency function of erythrocytes formed during the latter part of foetal life, the increase in number of circulating cells during this period and the relative decrease in circulating labelled cells in a simulated cord red blood cell survival experiment were calculated on a digital computer and compared with experimental data. Through the simulation procedure, the parameters in the life span frequency function and the production rate function were estimated. The life span frequency function of the red blood cells did not change appreciably during the last 60 days of foetal life. The mean cell life span was found to be between 45 and 70 days. The life span frequency function was skew with the majority of cells dying before the mean life span. The relative rate of production of erythrocytes during the last two months of gestation was found to be 3–5 times that of normal adults.