Correlation between K1 and K2 in the fractional clearance of bromosulphthalein in cattle and sheep suffering from different hepatotoxic diseases

Zusammenfassung Ein direkter Zusammenhang zwischen der crsten Phase (K₁) und der zweiten Phase (K₂) der fraktionellen Senkung des Bromsulphthaleinspiegels hat sich an von hepatoxischcn Krankheiten befallenen Kühen und Schafen erwiesen. Es ist anzunehmen, dass die K₂-Werte empfindlichere Nachweise der Lebertätigkeit in diesen Tieren aufweisen als die K₁-Werte.     

4-Thiouridine and photoprotection in Escherichia coli K 12]

A high level of protection is observed in the Escherichia coli K 12 strain AB 1157 rec A 1 nuv+ whose transfer RNA contains 4-thiouridine. In contrast, the photoprotection level is low and observed at higher doses in a strain which differs from the former by a single mutation, nuv-, (lack of 4-thiouridine). This nucleoside is therefore an important chromophore leading to photoprotection. This conclusion is corroborated by the similarity of the action spectra for 8-13 link formation in tRNA and for photoprotection.     

Membrane transport of Na and K and cell dehydration in sickle erythrocytes

The cellular concentration of Hb S plays a central role in the kinetic of Hb S polymerization and cell sickling. Blood of patients with homozygous sickle cell (SS) anemia contains a variable fraction of cells which are markedly dehydrated and have increased Hb S concentration. Since a decrease in cellular Hb S concentration reduces Hb S polymerization and sickling, the study of the processes leading to sickle cell dehydration has important pathophysiological and therapeutic implications. Sickle cell dehydration is due to cellular loss of K and Cl. K loss in sickle cells can take place via either the Ca²⁺-activated K⁺ channel, or the K?Cl cotransport, or the combined effect of oxidative damage and deformation of the red cell membrane. Inhibitors of K transport through these pathways could be used to prevent dehydration of sickle cells in vivo, provided that they can be administered safely.     

Hypothyroidism lowers blood pressure,adenylate cyclase and Na+, K+-and K+, Ca++-ATPase activities in normotensive and spontaneously hypertensive rats

Summary Myocardial isoproterenol-stimulated adenylate cyclase, Na⁺, K⁺-ATPase and K⁺, Ca⁺⁺-ATPase activities are elevated in the spontaneously hypertensive rat and can be lowered by methimazole-induced hypothyroidism which also prevents the development of hypertension. Although thyroid hormone levels are similar between untreated SHRs and WKY rats, the thyroid is apparently necessary for the expression of spontaneous hypertension.Acknowledgments. Supported by North Carolina Heart Grant No. 40301 and a grant from Sigma Xi.     

Macro-radioautographic localization of K42 and I131 in the canine kidney

Zusammenfassung Mittels der makroautoradiographischen Methode wurde festgestellt, dass die höchste Konzentration von K⁴² in der Nierenrinde, die maximale Konzentration von I¹³¹ im Nierenmark auftritt.     

Effect of K and Mg aspartate on cellular metabolism

Zusammenfassung Gasstoffwechselbestimmungen von unter K- und Mg-Asparaginat stehenden Zellenpräparaten isolierter Nephronen zeigen vermehrten Sauerstoffverbrauch. Der dabei unveränderte Atmungskoeffizient beweist, dass das oxydierte Substrat offenbar dasselbe bleibt.     

Ineffectiveness of adrenocorticosteroids and adrenocorticotropin in altering Na−K currents in squid giant axon

Zusammenfassung Adrenocorticosteroide und Adrenocorticotropin bewirkten in hohen Konzentrationen keine Änderungen der Na–K Ströme in Tintenfischriesenaxon; das weist darauf hin, dass die Ionenbegebenheiten, die das Axenpotential hervorrufen, durch diese Hormone nicht beeinflusst sind.     

Arousal-induced increase of cortical [K+] in unrestrained rats

Summary Changes of extracellular concentration of brain potassium [K⁺]_e were studied in lightly anesthetized unrestrained rats with ion-selective K⁺-microelectrodes introduced into the cerebral cortex with a head-mounted microdrive system. Nociceptive stimuli elicited EEG arousal lasting for 47 sec on the average which was accompanied by an increase of [K⁺]_e from 3.0 mM to 3.31 ± 0.04 mM.Acknowledgment. I wish to express my sincere gratitude to Dr. Bure from the Institute of Physiology, Czechoslovak Academy of Sciences, for his kind help in the preparation of this article.     

Periodicity in fish otolith Sr,Na, and K corresponds with visual banding

Examination of a section of an otolith from a teleost fish by fast atom bombardment-secondary ion mass spectrometry (FAB-SIMS) revealed seasonal periodicity in Sr, Na, and K concentrations that corresponded with visually observed annual banding. Strontium maxima also corresponded with Na and K minima and vice versa. In addition there was a general, apparently age-related, trend in Sr levels, with concentrations at the edge of the otolith being higher than in the core.     

Effects of temperature on K, Na and water movements in isolated hepatocytes]

Isolated hepatocytes incubated at 1 degrees C loss K, gain Na and water. Rewarming results in a transient increase in K and Na permeabilities. These are insensitive to quinine, suggesting that they are not caused by an intracellular Ca accumulation.     

Diagnostic tracking and model specification in combined forecasts of U.K. inflation

Combinations of several forecasts are now quite commonly used as inputs into business planning models. For example, capital budgeting generally involves a synthesis of several sources of economic forecasts. In such cases, where uncertainty and risk are also being explicitly considered, the statistical specification of the combined forecasts becomes particularly important. An investigation of the monthly forecasts of annual inflation from nine leading U.K. economic models was undertaken to examine the circumstances under which well-specified and efficient combined forecasts could be produced. This has helped to refine the general guidelines for the practical use of combinations in planning models.     

Dissociation of digoxin-like immunoreactivity and Na+,K+-ATPase inhibitory activity in rat plasma

We measured endogenous digitalis-like factor (EDF) in rat plasma during acute saline infusion by two different procedures. Na+,K+-ATPase inhibitory activity in the rat plasma significantly increased during saline loading (7.8 +/- 2.2 vs 2.5 +/- 0.9%, with and without acute saline loading, respectively, p less than 0.05). On the other hand, the plasma digoxin-like immunoreactivity significantly decreased during acute saline loading (16.9 +/- 1.6 vs 32.0 +/- 2.8 pg digoxin equivalents/ml, with and without acute saline loading, respectively, p less than 0.01). These results indicate that the major substances detected by digoxin-like immunoreactivity and direct Na+,K+-ATPase inhibitory activity are completely different, at least in rat plasma.     

Blockade by zinc ions of K+-induced contraction and calcium in guinea pigTaenia coli

Preincubation with 0.3 mM Zn²⁺ markedly inhibited both the tonic response and Ca²⁺ binding at low affinity sites induced by K⁺ (60 mM), with smaller effects on the phasic response and the high affinity Ca²⁺ sites, inTaenia coli. However, when the muscle was kept in Zn²⁺-containing medium following the first stimulation with the K⁺, the phasic response and the high affinity Ca²⁺ sites were more severely inhibited during the second stimulation with K⁺. This probably indicates that Zn²⁺ reduced the tonic tension response to K⁺ mainly by inhibiting Ca²⁺ influx at the cell membranes ofTaenia coli. However, when Zn²⁺ is continuously present, Ca²⁺ is not supplied at the storage sites and is not available for the phasic response to a second stimulation with K⁺.     

Physiologic and genetic analysis of a mutant excreting alkaline phosphatase in Escherichia coli K 12

A physiological analysis of an E. coli K 12 periplasmic-leaky mutant shows that specific excretion of periplasmic proteins increases with time and temperature of incubation when cells are grown in rich L medium. The associated lky mutation was mapped by use of conventional genetic techniques near the gal locus.