Acute abdomen in a patient treated with lamprene

Patients receiving Lamprene may develop acute abdominal symptoms which simulate an abdominal emergency. Withdrawal of the drug relieves these symptoms. The absorption of Lamprene can be increased and deposition in the reticuloendothelial system as crystals can be avoided if it is administered in an alcoholic medium.

Cyanide production from glycine by a homogenate from a Pseudomonas species

A cell-free preparation with cyanide-producing activity was obtained from a bacterium, strain C, of the genus Pseudomonas. To preserve activity, an oxidizing agent, e.g., phenazine methosulphage (PMS), had to be added to the cell suspension before disruption by sonic treatment. By the procedure described, a total homogenate made from a 15% (wet weight) bacterial suspension in tris(hydroxymethyl)aminomethane-hydrochloride buffer (0.05 M, pH 8.2) and with PMS (0.4mM) exhibited about 8% of the activity obtained from a suspension of untreated bacteria. In the presence of flavine-adenine dinucleotide (0.3 mM) and PMS (0.4mM), the activity was augmented to about 16% of that of the intact cells. By gradient centrifugation the homogenate was separated into three fractions. The main enzyme activity was associated with those fractions which by electron microscopy were found to consist of membranous structures.

Bacterial calcium transport: energy-dependent calcium uptake by membrane vesicles from Bacillus megaterium

Membrane vesicles capable of energy-dependent calcium uptake have been prepared from Bacillus megaterium cells in log-phase growth or when undergoing sporulation. The uptake is dependent on the calcium concentration and appears saturable in vesicles from cells in log-phase growth. Both ascorbate and phenazine methosulfate are needed as a source of electrons for the energy-dependent increase in calcium uptake. Addition of 8 mM sodium cyanide inhibited the energy-dependent uptake. If this calcium uptake mechanism is a component of the sporulation-specific calcium accumulation process, the latter's functional expression would appear to be inhibited during log-phase growth.

Substrate specificity of the purified primary alcohol dehydrogenases from methanol-oxidizing bacteria

Hyphomicrobium strain WC, Pseudomonas strain TP-1, and Pseudomonas strain W1 are capable of growth on methanol as the sole source of carbon and energy. Methanol-grown cells of each organism contain a primary alcohol dehydrogenase that has been purified to homogeneity. Each enzyme has a molecular weight of 120,000 and shows an in vitro requirement for phenazine methosulfate and ammonium ions for enzymatic activity. Normal aliphatic alcohols are oxidized rapidly by each enzyme. The presence of a methyl group on the carbon atom adjacent to the primary alcohol group lowers the enzymatic activity. This effect is reduced as the methyl substituent is moved further away from the hydroxyl group. The effect of other substituents on enzymatic activity is reported. Methanol, formaldehyde, and to a limited extent acetaldehyde are oxidized by the primary alcohol dehydrogenases. Higher aldehydes are not oxidized. A possible explanation for this specificity, with regard to aldehydes, is presented in terms of degree of hydration of the aldehyde.

Cyanide formation from oxidation of glycine of Pseudomonas species

With whole cells of a hydrogen cyanide-producing bacterium strain C, of the genus Pseudomonas, it was found that the oxygen necessary for the oxidation of glycine to cyanide could be replaced by various artificial electron acceptors. The order of reactivity was: oxygen > phenazine methosulphate > methylene blue > 2,6-dichlorophenolindophenol > ferricyanide. Cyanide production was inhibited by pyrrolnitrin, a well-known inhibitor of many flavine enzymes. The molar ratio of added glycine to cyanide produced was found to be 1.09. With whole bacteria the apparent K(m) (glycine) for the cyanide production was found to be 5.0 x 10(-4) M.

New procedure for the isolation of membrane vesicles of Bacillus subtilis and an electron microscopy study of their ultrastructure

A rapid procedure for the isolation of membrane vesicles of Bacillus subtilis is described that minimizes the action of proteolytic enzymes, excreted by this organism, on the membrane proteins. The membrane vesicles obtained have, in addition to a low endogenous respiration rate, a low endogenous activity for transport of amino acids and carboxylic acids. In the presence of the electron donor, ascorbate-phenazine methosulfate, the transport activities for these compounds were comparable to the activities of intact cells. In addition, these activities were retained for a prolonged period of time. Electron microscopy examination of thin sections of the vesicles showed that the preparation consisted almost exclusively of membrane vesicles which were not contaminated with other cell components. The membrane vesicles, which are six to seven times smaller in diameter than protoplasts, often enclosed smaller vesicles. Freeze-etching of intact cells, protoplasts, and membrane vesicles showed that the orientation of the membrane of the vesicles was identical to the orientation of the plasma membrane in intact cells and protoplasts. This also held for the majority of the membranes of the enclosed vesicles, only 15% having the opposite orientation.

The photochemical activities and electron carriers of developing barley leaves

The development of photochemical activities in isolated barley plastids during illumination of dark-grown plants has been studied and compared with the behaviour of plastocyanin, cytochromes f, b-559(LP), b-563 and b-559(HP) and pigments P546 (C550) and P700. Electron-transport activity dependent on Photosystem 1 and cyclic photophosphorylation dependent on N-methylphenazonium methosulphate (phenazine methosulphate) were very active relative to the chlorophyll content after only a few minutes of illumination of etiolated leaves, and then rapidly declined during the first few hours of greening. By contrast, Photosystem 2 activity (measured with ferricyanide as electron acceptor) and non-cyclic photophosphorylation were not detectable during the first 2(1/2)h of greening, but then increased in total amount in parallel with chlorophyll. The behaviour of the electron carriers suggested their association with either Photosystem 1 or 2 respectively. In the first group were plastocyanin, cytochrome f and cytochrome b-563, whose concentrations in the leaf did not change during greening, and cytochrome b-559(LP) whose concentration fell to one-half its original value, and in the second group were cytochrome b-559(HP) and pigment P546, the concentrations of which closely followed the activities of Photosystem 2. Pigment P700 could not be detected during the first hour, during which time some other form of chlorophyll may take its place in the reaction centre of Photosystem 1. The plastids started to develop grana at about the time that Photosystem 2 activity became detectable.

Effect of withdrawal from chronic ethanol ingestion on phenazine methosulfate uptake by brain mitochondria and nerve endings

The effect of ethanol withdrawal on the uptake of phenazine methosulfate (PMS) by brain synaptosomal and mitochondrial fractions was studied. Prior studies showed that rats made ethanol dependent developed an abnormality in brain mitochondria characterized by an increase in O2 consumption during succinate-supported respiration when PMS was used as an electron acceptor. In the present study it was shown that ethanol withdrawal induced an increase in PMS uptake by brain mitochondrial and synaptosomal fractions during succinate oxidation. PMS uptake was measured directly. Calcium stimulated the succinate-supported PMS uptake in ethanol-withdrawn rats and controls to the same final level indicating that the maximum uptake of PMS was not affected by withdrawal. The results support the hypothesis that the increase in O2 consumption observed in rat brain mitochondria during ethanol withdrawal was due to an increase in transport of PMS.

Sensitivity to myxin of Escherichia coli treated with ethylenediaminetetraacetic acid

Sensitivity to the antibiotic myxin was significantly increased in Escherichia coli 15T− cells treated with ethylenediaminetetraacetic acid (2 mM) for 5 min. This treatment did not reverse the resistance to myxin in cells of a myxin-resistant strain. Cells of both the susceptible and the resistant strains accumulated myxin intracellularly to the same extent.

Phenazine methosulfate uptake by rat liver mitochondria

Calcium stimulated phenazine methosulfate (PMS) accumulation by rat liver mitochondria. PMS uptake required succinate, cyanide, and low O2 tension. The NADH-generating substrate β-hydroxybutyrate did not support PMS accumulation. The rate of PMS uptake was temperature dependent. Amytal, antimycin A, oligomycin, dinitrophenol, and malonate inhibited PMS uptake indicating that electron flow through the respiratory chain was involved. A 100% O2 atmosphere caused PMS efflux from mitochondria which had accumulated PMS anaerobically. It is postulated that PMS is sequestered in mitochondria as a precipitate when reduced by electron transfer. Nonenzymatic oxidation of PMSH by molecular oxygen solubilizes it and efflux from the mitochondria follows.

Intermediates in fatty acid oxidation

1. Aqueous extracts of acetone-dried liver and kidney mitochondria, supplemented with NAD(+), CoA and phenazine methosulphate, efficiently convert fatty-acyl-CoA compounds into acetyl-CoA; the process was followed with an O(2) electrode. 2. Label from [1-(14)C]octanoyl-CoA appears in acetyl-CoA more rapidly than that from [8-(14)C]octanoyl-CoA. 3. Oxidation of [8-(14)C]octanoyl-CoA was terminated by addition of neutral ethanolic hydroxylamine and the resulting hydroxamates were separated chromatographically. Hydroxamate derivatives of 3-hydroxyoctanoyl-, hexanoyl-, butyryl- and acetyl-CoA were obtained. 4. These and other observations suggest that oxidation of octanoyl-CoA by extracts involves participation of free intermediates rather than uninterrupted complete degradation of individual molecules to acetyl-CoA by a multienzyme complex. 5. Intact liver mitochondria studied by the hydroxamate technique were also shown to form intermediates during oxidation of labelled octanoates. In addition to octanoylhydroxamate, [8-(14)C]octanoate gave rise to small amounts of hexanoyl-, butyryl- and 3-hydroxyoctanoyl-hydroxamate. In contrast with extracts, however, where the quantity of intermediates found was a significant fraction of the precursors, mitochondria oxidizing octanoate contained much larger quantities of octanoyl-CoA than of any other intermediate.

Pyocyanine degradation by apyocyanogenic strains of Pseudomonas aeruginosa

Six apyocyanogenic strains of Pseudomonas aeruginosa were shown to be capable of degrading pyocyanine under conditions normally conducive to pigment formation. P. aeruginosa B-275 was shown to metabolize pyocyanine to the extent that it was no longer chloroform extractable by following the fate of 14C-labeled pyocyanine. Also, P. aeruginosa B-275, an apyocyanogenic strain, was found capable of producing pyocyanine by the dilution of radioactivity in undegraded 14C-labeled pigment.