Effects of steroids on Tetrahymena.

Phagocytosis of Tetrahymena is inhibited by prednisolone-sodium-succinate and deoxy-corticosterone-glucoside, and stimulated by dexamethasone and prednisolone. Dexamethasone and estradiol enter the cells and are localized first in food vacuoles, and later on in the cytosol. They were never found in the nucleus. The demonstration by biochemical methods of a specific glucocorticoid binding protein failed in all three subcellular fractions examined.     

Sequestration of arginine by polyphosphate in vacuoles of yeast (Saccharomyces cerevisiae)

The conditions for synthesis, purification, and properties of tryptophanase by a marine organism (Vibrio K-7) were studied. Tryptophanase was induced by tryptophan and its analogs, and partially repressed by 0.5% glucose or glycerol. NaCl (0.4M) was required for optimal growth and tryptophanase activity in whole cells. The enzyme was purified to 92% homogeneity by heat treatment, hydroxyapatite chromatography and fractionation with ammonium sulfate. This tryptophanase has been found to have kinetic properties similar to the tryptophanase from other microorganisms. It carries out both , -elimination reactions (using tryptophan, serine, cysteine and S-methyl-cysteine as substrates) and -replacement reactions (forming tryptophan from indole and serine, cysteine or S-methyl-cysteine). The enzyme has a sedimentation coefficient of 9.2S and requires pyridoxal 5-phosphate as a cofactor. The optimal pH for the tryptophanase reaction is pH 8.0.Nonstandard Abbreviations PLP pyridoxal 5-phosphate - TPase tryptophanase - TSase tryptophan synthase - DHase dehydratase - TCA tricarboxylic acid - BSA bovine serum albumin Preliminary reports of this work have been presented (M. J. Klug and R. D. DeMoss, Bacteriol. Proc. 1971, p. 132; D. D. Whitt and R. D. DeMoss, Abstr. Annu. Meet. Am. Soc. Microbiol. 1973, p. 148)     

The role of estrogens in the regulation of lactate dehydrogenase activity and its submolecular organization in rat anterior pituitary

Estrogens increase LDH activity and decrease H/M subunit ratio in rat anterior pituitary in both the experimental circumstances and the physiological conditions. The cellular messengers mediating estrogenic effect are structure- and stereospecific. The activity increasing and subunit ratio decreasing potency of the three tested estrogens was of following decreasing order: 17 beta-estradiol, estrone, and estriol. 17 alpha-estradiol did not affect activity parameters and submolecular organisation of the enzyme. The estrogen induced activity increase is consequence of the enhanced de novo enzyme protein synthesis which could be inhibited by Actinomycin-D. The lack of adrenocorticoids did not involve the alteration of LDH activity and H/M ratio in female rat anterior pituitary. Accordingly, these steroids do not mediate estrogenic action. 17 beta-estradiol had a substantial increasing effect on LDH activity in the subrenal implanted pituitary homografts and decreased H/M subunit ratio. Pituitary LDH activity in androgenized female rats decreased only after the removal of the polycystic ovaries. The two latter observations suggest that hypothalamic hormones are not involved in the regulation of pituitary LDH activity and its submolecular organization. De novo synthesis of LDH enzyme protein and the regulation its submolecular organization is induced by the direct action on anterior pituitary cells of the estrogens.     

A theoretical analysis of the binding of palmitate by human serum albumin

The distribution of palmitate between the form bound by human serum albumin and the free form in plasma was calculated by use of 12 stepwise equilibrium constants and a computer program. Computations were carried out for molar ratios of palmitate to serum albumin of 0.5, 1,2,3, and 4. At most 0.0003% of the palmitate would be in the unbound form, and the remainder distributed among different complexes with albumin. At low molar ratios, the complexes with 1 to 2 moles of palmitate/albumin would predominate while at the highest ratio the complexes of 3 and 4 moles of palmitate/albumin would be most abundant. In the delivery of palmitate to tissues the relative contribution of the different complexes would change, as the molar ratio of fatty acid to albumin changed.     

Glucose concentration gradient through the cerebral cortex in normoglycaemic anaesthetized rabbits

In this pilot study, the relationships between glucose and lactate concentrations of plasma, cerebrospinal fluid (CSF), cerebral cortex and subjacent white matter were investigated in one hyperglycaemic and three normoglycaemic anaesthetized rabbits. After a 90 min stabilization period, CSF was sampled and the brain frozen in situ. Triplet samples (n = 3 X 21) were obtained from the outer and inner halves of cortex and from the white substance and analysed for their water content as well as for glucose and lactate by enzymatic fluorescence methods. Preservation of the ATP content was demonstrated in brain slices by a bioluminescence method. The glucose and lactate levels of CSF seemed to reflect those of the outer half of the cortex. In the normoglycaemic animals, the tissue glucose and tissue lactate levels correlated inversely (r = 0.477: p less than 0.01). While the glucose concentrations were nearly identical in the inner cortex and white substance, there was a concentration difference of 0.54 mmol/kg tissue water between the outer half of the cortex and the white matter (p much less than 0.02). This might correspond to a steep intra-cortical glucose gradient starting from the CSF-facing surface and approximating the general cerebral glucose level in a depth of about 4-500 microns. The possible significance of this gradient in regulating CSF glucose is discussed.     

Bladder tissue characterization using probe‐based Raman spectroscopy: Evaluation of tissue heterogeneity and influence on the model prediction

Existing approaches for early‐stage bladder tumor diagnosis largely depend on invasive and time‐consuming procedures, resulting in hospitalization, bleeding, bladder perforation, infection and other health risks for the patient. The reduction of current risk factors, while maintaining or even improving the diagnostic precision, is an underlying factor in clinical instrumentation research. For example, for clinic surveillance of patients with a history of noninvasive bladder tumors real‐time tumor diagnosis can enable immediate laser‐based removal of tumors using flexible cystoscopes in the outpatient clinic. Therefore, novel diagnostic modalities are required that can provide real‐time in vivo tumor diagnosis. Raman spectroscopy provides biochemical information of tissue samples ex vivo and in vivo and without the need for complicated sample preparation and staining procedures. For the past decade there has been a rise in applications to diagnose and characterize early cancer in different organs, such as in head and neck, colon and stomach, but also different pathologies, for example, inflammation and atherosclerotic plaques. Bladder pathology has also been studied but only with little attention to aspects that can influence the diagnosis, such as tissue heterogeneity, data preprocessing and model development. The present study presents a clinical investigative study on bladder biopsies to characterize the tumor grading ex vivo, using a compact fiber probe‐based imaging Raman system, as a crucial step towards in vivo Raman endoscopy. Furthermore, this study presents an evaluation of the tissue heterogeneity of highly fluorescent bladder tissues, and the multivariate statistical analysis for discrimination between nontumor tissue, and low‐ and high‐grade tumor.     

Sharing the moment: the duration of embraces in humans

Moments of some gestures may stand out from our constantly flowing life-time as memorable experiences. We feel subjective moments as our psychological present. Few behavioral acts can express a shared subjective experience so easily observable than people’s embraces after a significant life-event. Spontaneous embraces from the 2008 Summer Olympics Games were analysed, and were found to last for about 3 s, comparable to previously described perceptual and motor units in humans and also in other primate species. These 3-s segments of time are suggested to be the basic temporal building blocks of our behaviourally expressed subjective experiences.     

A microcomputer method for recording and analysing behavioural elements

The trend in ethology, psychopharmacology and behaviour genetics is to get increasingly higher resolution of the behaviour of animals, since it increases the sensitivity of the tests used. Consequently the higher resolution requires an increased data-logging efficiency, and a decreased time-investment for data handling. In this paper a method for inexpensive microcomputers is presented, which enables an individual experimenter to obtain frequency, relative duration and its variance from as many behavioural elements as desired.