Effects of general anesthetics on search in memory in man.

Recovery of search functions in long-term memory following several hours of anesthesia was studied on human volunteers. Verbal as well as visual search was assessed. The anesthetics used, fluroxene and halothane, slowed down considerably the verbal search for the first few hours following anesthesia, but had very little effect on the following day. No effect was observed a week later. Visual search was not affected at all, in accordance with previous findings indicating a selective effect of low concentrations of inhalation anesthetics on verbal memory.     

Relationship between the chromatoid body and the acrosomal system in early spermatids of Myxine glutinosa L.

Summary A transient close relationship between the chromatoid body and the developing acrosome is demonstrated in early spermatids of Myxine glutinosa.This work was supported by the Norwegian Research Council for Science and Humanities (NAVF, Grant Nr. D 61.44) and the Austrian Fonds zur Förderung der wissenschaftlichen Forschung, Projekt 2183     

Cell surface charge and regulation of cell division of 3T3 cells and transformed derivatives.

The cell surface charge of 3T3, 3T6, SV40-3T3 cells and trypsin-, neuraminidase- and serumtreated preparations of these has been characterized by microcell electrophoresis. At 25 °C, density-inhibited 3T3 cells show a decrease in electrophoretic mobility when treated with various stimuli of cell division. This effect is not observed at 25 °C for transformed derivatives. The surface charge configuration of various cell preparations exhibits a thermal transition which is located within a temperature range characteristic of each preparation. These and other results from cell electrophoresis, taken together with those obtained in agglutination studies by other authors, are considered evidence for the occurrence in the plasma membrane of these cells of a twodimensional phase separation. The temperature range of this phase separation is shifted on treating the cells by growth stimuli. This effect might be an indication of a basic trigger mechanism in the cell cycle.     

The effect of streptococcus on the persistence of Brugia malayi and on the production of elephantiasis in cats

Cats were exposed to 200 Brugia malayi larvae on one hind foot over a 3 week period. Six weeks after the initial exposure to B. malayi, 10 of the cats were challenged on both hind legs with a Group G streptococcus. The remaining 10 cats were not exposed to the streptococcus. Following bacterial challenge, the B. malayi-infected leg of 9 of 10 cats displayed sequelae including erysipelas and abscesses. In addition, 5 of the affected legs had an elephantoid appearance, both by gross observation and as seen at necropsy 10 weeks after the initial B. malayi infection. The contralateral, uninfected leg of each cat remained normal in appearance. Histologic processing and examination of the elephantoid tissue showed it to be collagen; eosinophils and mast cells were plentiful in the collagen matrix. In the controls, only 1 animal displayed erysipelas and no abscesses were seen. Lymphedema seen in the B. malayi-infected leg of 5 control cats was less extensive than in uninfected cats challenged with streptococci and at necropsy no significant collagen matrix was evident. The location and number of worms in the lymphatics were noted. This study demonstrated that secondary microbial infections can contribute to the causation of elephantiasis under certain circumstances and that developing B. malayi were in some way adversely affected by the streptococcal involvement of the filaria-infected lymphatics.     

Progesterone binding components of chick oviduct. X. Purification by affinity chromatography.

Cytoplasmic progesterone receptors of chick oviduct have been purified in 8% yield by steroid affinity and ion exchange chromatography. The affinity resin, deoxycorticosterone-bovine serum albumin-Sepharose, binds progesterone receptors with high affinity (KD equals 8 times 10-minus 10 M) and its use resulted in a greater than 2000-fold purification over the starting material in a single step. DEAE-Sephadex A-50 chromatography was then used to achieve final purification. NA dodecyl-SO4 gel electrophoresis and DEAE-cellulose chromatography showed that the purified receptors contained both of the previously described 4 S progesterone binding components in near equal amounts. Na dodocyl-SO4 gel electrophoresis also showed that these components consisted of single polypeptide chains with molecular weights of 110, 000 (A component) and 117, 000 (B component). There was no evidence for subunits of lower molecular weight. The purified materials have identical hormone-binding kinetics and steroid specificity to crude cytosol receptors. The isolated receptors retain the three biologically important properties exhibited by progesterone binding components present in cruder preparations: they bind specifically to (a) nuclei (KD equals 1.1 times 10-minus 9 M, 10, 000 sites per nucleus); (b) chromatin (KD equals 3 times 10-minus 9 M, 2000 sites per pg of DNA-);and (C) DNA.     

Role of D-tryptophan oxidase in D-tryptophan utilization by Escherichia coli.

Mutants of Escherichia coli K-12 that require L-tryptophan (trp) are normally unable to utilize D-tryptophan to fulfill their requirement. However, secondary mutations (dadR) that confer this ability can be isolated. In such strains two distinct enzymes are found to be produced at high levels: D-amino acid oxidase (EC 1.4.3.3) and D-tryptophan oxidase. A convenient assay procedure for D-tryptophan oxidase is described. The two enzymes could be distinguished on the basis of their sensitivity to inhibition by L-phenylalanine and L-tyrosine. Strains that were trp dadR could not grow with D-tryptophan in the presence of L-phenylalanine, but further mutations, Fyo, could be isolated that allowed growth under these conditions. Some of them were characterized by further increases in the level of D-tryptophan oxidase activity and a sharp decrease in D-amino acid oxidase. These kinds of Fyo mutations lay in or near the dadR gene. The substrate specificity of the two enzymes toward a large number of compounds was examined. The transamination of aromatic keto acids was investigated. In the wild-type strain only a single enzyme, transaminase A (EC 2.6.1.5), was found, and it was irreversibly activated when subjected to elevated temperatures. The present state of our knowledge on D-amino acid utilization in E. coli is summarized.     

Luteal 20alpha-hydroxy steroid dehydrogenase and the formation of delta4-3-oxo steroids in the rat after weaning or treatment with 2-bromo-alpha-ergocryptine during lactation.

Natural or early weaning of rat litters caused an increased activity of maternal luteal 20alpha-hydroxy steroid dehydrogenase and a decreased release of delta4-3-oxo steroids in vitro. 2. Compound CB-154 (2-bromo-alpha-ergocryptine) caused an increase of 20alpha-hydroxy steroid dehydrogenase activity in mid-lactation but not in early lactation. 3. Prolaction did not prevent these increases in enzyme activity.