Common components of industrial metal-working fluids as sources of carbon for bacterial growth

Water-based metal-working fluids used in large-scale industrial operations consist of many components, but in the most commonly used formulations only three classes of components are present in high enough concentrations that they could, in principle, provide enough carbon to support the high bacterial densities (10 CFU/ml) often observed in contaminated factory fluids. These components are petroleum oil (1 to 5%), petroleum sulfonates (0.1 to 0.5%), and fatty acids (less than 0.1%, mainly linoleic and oleic acids supplied as tall oils). We isolated pure strains of predominating bacteria from contaminated reservoirs of two metal-working systems and randomly selected 12 strains which we tested in liquid culture for growth with each of the metal-working fluid components as the sole source of carbon. Of the 12 strains, 7 reached high density (10 CFU/ml from an initial inoculum of less than 2 x 10) in 24 h, and 1 strain did the same in 48 h with 0.05% oleic or linoleic acid as the carbon source. These same strains also grew on 1% naphthenic petroleum oil but required up to 72 h to reach densities near 10 CFU/ml. One strain grew slightly and the others not at all on the petroleum sulfonates. The four remaining strains did not grow on any of the components, even though they were among the predominating bacteria in the contaminated system. Of the seven strains that grew best on the fatty acids and on the naphthenic petroleum oil, five were tentatively identified as Acinetobacter species and two were identified as Pseudomonas species. Four of the bacteria that did not grow were tentatively identified as species of Pseudomonas, and one could not be identified.     

Effects of atrial natriuretic factor on renal function and cyclic GMP production

Anesthetized beagle dogs received increasing doses of continuous infusions of a 26-amino-acid synthetic atrial natriuretic factor (ANF). Urinary sodium excretion rose in a dose-dependent manner to a maximum level similar to that seen after hydrochlorothiazide administration. Mean arterial blood pressure decreased, but only modestly, and not in a dose-dependent fashion. Dogs chronically retaining NaCl secondary to constriction of the thoracic inferior vena cava showed only modestly enhanced natriuresis when infused with similar levels of ANF. When ANF was infused directly into the renal artery of anesthetized beagles, a dose-dependent natriuresis and calciuresis were observed with maximal fractional sodium excretion averaging approximately 8%. Although glomerular filtration tended to increase, the average dose-related changes were not significant. Cyclic GMP excretion was increased during intra-renal-arterial infusion of ANF. Excretion of cyclic GMP by both the infused and noninfused kidneys was equal, which suggests that urinary cyclic GMP was not nephrogenous but derived from the elevated circulating levels. These and other data from rats dissociate changes in urinary cyclic GMP excretion and sodium excretion.     

Lipid Composition of Whole Roots and of Ca2+, Mg2+-activated Adenosine Triphosphatases from Wheat and Oat as Related to Mineral Nutrition

Lipid composition of whole roots of wheat (Triticum vulgare Vill. cv. Svenno Spring Wheat) and oat (Avena sativa L. cv. Brighton) and of cell wall fractions, mitochondrial fractions and microsomal fractions of these roots were studied. Lipid composition depended upon the level of mineral nutrition. In wheat total phospholipids, phosphatidyl choline and sulfolipid content was highest in the roots grown at the higher salt concentration, while the reverse was true for oat roots. In both species glycolipid and sterol content was lower in the high salt roots, at the same time as higher proportions of them were built into the microsomal fraction. Phosphatidyl choline content of the wheat root membrane fractions increased with the salt level, while the opposite occurred in the oat roots. The phosphatidyl choline content may be correlated with the (Ca²⁺, Mg²⁺)-stimulated ATPase activity.     

Low Doses of Imatinib Induce Myelopoiesis and Enhance Host Anti-microbial Immunity

Imatinib mesylate (Gleevec) inhibits Abl1, c-Kit, and related protein tyrosine kinases (PTKs) and serves as a therapeutic for chronic myelogenous leukemia and gastrointestinal stromal tumors. Imatinib also has efficacy against various pathogens, including pathogenic mycobacteria, where it decreases bacterial load in mice, albeit at doses below those used for treating cancer. We report that imatinib at such low doses unexpectedly induces differentiation of hematopoietic stem cells and progenitors in the bone marrow, augments myelopoiesis but not lymphopoiesis, and increases numbers of myeloid cells in blood and spleen. Whereas progenitor differentiation relies on partial inhibition of c-Kit by imatinib, lineage commitment depends upon inhibition of other PTKs. Thus, imatinib mimics “emergency hematopoiesis,” a physiological innate immune response to infection. Increasing neutrophil numbers by adoptive transfer sufficed to reduce mycobacterial load, and imatinib reduced bacterial load of Franciscella spp., which do not utilize imatinib-sensitive PTKs for pathogenesis. Thus, potentiation of the immune response by imatinib at low doses may facilitate clearance of diverse microbial pathogens.