Specific electron donor-energized transport of alpha-aminoisobutyric acid and K+ into intact cells of a marine pseudomonad

The transport of alpha-aminoisobutyric acid and K(+) into K(+)-depleted cells of a marine pseudomonad (ATCC 19855) was stimulated strongly by ethanol, reduced nicotinamide adenine dinucleotide (NADH), and ascorbate-reduced N, N, N', N'-tetramethyl-p-phenylenediamine. In the presence of the quinone inhibitor 2-heptyl-4-hydroxyquinoline-N-oxide, only ascorbate-reduced N, N, N', N'-tetramethyl-p-phenylenediamine was active. Primary and secondary, but not tertiary, alcohols from ethanol to n-amyl alcohol stimulated both alpha-aminoisobutyric acid and K(+) transport and were oxidized by the cells. Malate and succinate, which were oxidized rapidly by the cells, had little or no capacity to energize the transport of alpha-aminoisobutyric acid into K(+)-depleted cells but were partially effective in promoting K(+) uptake. Ethanol stimulated the transport of alpha-aminoisobutyric acid into K(+)-preloaded cells. The transport of both alpha-aminoisobutyric acid and K(+) was inhibited 20% by iodoacetate, 85% by N-ethylmaleimide, and 90 to 100% by both NaCN and p-chloromercuribenzoate. The addition of Na(3)Fe(CN)(6) permitted the ethanol-induced transport of alpha-aminoisobutyric acid into K(+)-preloaded cells in the presence of NaCN, but little or no uptake of alpha-aminoisobutyric acid or of K(+) into K(+)-depleted cells under the same conditions. The transport of alpha-aminoisobutyric acid into K(+)-depleted cells required both K(+) and an electron donor. The oxidation of NADH and ethanol by K(+)-depleted cells was stimulated strongly by K(+). Parallels between these studies and those with membrane vesicles show that results with membrane vesicles of the marine pseudomonad have physiological significance for the intact cells. The results support the conclusion that the energy for the active transport of both alpha-aminoisobutyric acid and K(+) into cells of this organism is provided by electron flow through a region of the respiratory chain lying between cytochrome c and O(2).

The role of eye movements in the perception of the horizontal-vertical illusion

An experiment examining the role of eye movements in the determination of magnitude of the horizontal—vertical illusion (HVI) was performed by presenting the stimulus figures in conditions where eye movements or tendencies to eye movements were eliminated (i.e. presenting small figures tachistoscopically). The major result was that the illusion occurred within these conditions, indicating that eye movements do not play a major role in the production of the HVI. However, the finding that the magnitude of the HVI was positively affected in the conditions where tendencies to make eye movements were possible suggests that they exert a secondary role.

Operant conditioning in the treatment of anorexia nervosa: a review and retrospective study of 11 cases

Anorexia nervosa is a disorder characterized by loss of appetite, amenorrhoea, and weight loss in the absence of any primary psychiatric or physical illness (Dally and Sargant, 1966). Features which have recently been stated to be of value in distinguishing it from anorexia due to other causes are: denial of illness, bradycardia and lanugo hair (Wright et al., 1969). The weight losses in this condition are usually at least 20 per cent of ideal body weight, depending on the quality and promptness of treatment.

The effect of glucocorticosteroids on the proliferation and kinetics of promonocytes and monocytes of the bone marrow

To elucidate mechanisms underlying the prolonged monocytopenia induced in the peripheral blood of mice by injection of a subcutaneous depot of hydrocortisone acetate, the effect of this compound on the production of monocytes and their release from the bone marrow was studied. Hydrocortisone was found to cause a rapid reduction of the bone marrow promonocytes to about 65% of their initial number. The number of monocytes in the bone marrow decreased gradually, over a period of 96 h, to 75% of the initial value. The mitotic activity of the promonocytes was not diminished, as judged from the labeling in vitro with [(3)H]thymidine and the DNA-synthesis and cell-cycle times of these cells. The production of monocytes was only moderately diminished, i.e., to about 80% of the normal amount. The release of monocytes from the bone marrow was found to be influenced by hydrocortisone. After in vivo labeling with [(3)H]thymidine the monocyte-labeling indices were initially significantly higher in hydrocortisone-treated than in normal mice. It is concluded that a decreased production of monocytes in the bone marrow cannot account for the prolonged monocytopenia in the peripheral blood after hydrocortisone administration. However, hydrocortisone interferes with the release of newly formed monocytes from the bone marrow, resulting in a prolonged sojourn of these cells in this compartment.

Erratum: Physiological and morphological effects of phenethyl alcohol upon a gram-negative marine pseudomonad

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Distribution of alkaline phosphatase within the periplasmic space of gram-negative bacteria

Both reaction-product localization and ferritin-coupled antibody studies have shown that alkaline phosphatase is evenly distributed throughout the peri-plasmic space of Escherichia coli and a marine pseudomonad. This space is not locally enlarged except in cases where plasmolysis has occurred.

Physiological and morphological effects of phenethyl alcohol upon a gram-negative marine pseudomonad

Phenethyl alcohol (PEA) at 0.15% (v/v) inhibited the growth of a gram-negative marine pseudomonad. After removal of the alcohol, the cells remained viable even when pre-exposed to PEA concentrations as high as 0.25% (v/v). Phenethyl alcohol inhibited uptake of α-aminoisobutyric acid (AIB) and also prevented amino acid exchange. At PEA concentrations of 0.25% or less, inhibition of AIB uptake was completely reversible and, provided K+ was added to the uptake medium, the treated cells could accumulate AIB to the same extent as control cells. If K+ was omitted from the medium, the capacity of the cells to accumulate AIB was found to be proportional to the length of time that the cells had been exposed to the alcohol. Phenethyl alcohol caused a rapid efflux of intracellular K+ and AIB-14C from previously loaded cells, and such cells were noticeably smaller than normal cells and had a plasmolyzed or irregular outline when observed by phase contrast. Thin section electron microscopy, and freeze-etch studies, showed that the plasmolyzed appearance of these cells was due to local invagination of the cytoplasmic membrane. After removal of the alcohol, the subsequent addition of K+ to the incubation medium caused the cells to become deplasmolyzed. It seems likely that the inhibition of cell growth by PEA is due to two major causes: (1) direct interference of the compound with the normal physiological functions of the cytoplasmic membrane and, (2) PEA induced structural changes occurring within the cell envelope.

Induced morphological changes in the stainable layers of the cell envelope of a gram-negative bacterium

Manipulation of ion concentration can be used to produce profound changes in the morphology of both the cytoplasmic membrane and the outer double-track layer of the cell envelope of the marine pseudomonad studied here. The fact that these layers are deformable, without any changes in the morphology of the rigid peptidoglycan layer, suggests that both have a "plastic" physical nature.