Resistance issues and treatment implications: pneumococcus, Staphylococcus aureus, and gram-negative rods

During the last decade there has been an unexpectedly rapid evolution of antimicrobial resistance in the respiratory pathogens for community- and hospital-acquired pneumonia. In order to choose the most optimal therapy for their patients, it is essential that physicians be aware of the prevalence and mechanisms of resistance and their implications on the effectiveness of the various antimicrobials.     

Mechanism of suppression of cell-mediated immunity by measles virus

The mechanisms underlying the profound suppression of cell-mediated immunity (CMI) accompanying measles are unclear. Interleukin-12 (IL-12), derived principally from monocytes and macrophages, is critical for the generation of CMI. Measles virus (MV) infection of primary human monocytes specifically down-regulated IL-12 production. Cross-linking of CD46, a complement regulatory protein that is the cellular receptor for MV, with antibody or with the complement activation product C3b similarly inhibited monocyte IL-12 production, providing a plausible mechanism for MV-induced immunosuppression. CD46 provides a regulatory link between the complement system and cellular immune responses.     

Crystallization of PbO·2B2O3 from Its Supercooled Melt

The growth of lead diborate and the viscosity of its melt were determined as a function of temperature. These data were used to examine several theories of the growth of crystals from the melt. The data were in good agreement with the theory of Tornbull and Cohen. At large under coolings the growth rate appeared to be controlled by the rate of diffusion across the crystal-melt interface, whereas at smaller undercoolings the growth rate appeared to be controlled by reaction at the crystal-melt interface.     

Radiochlorine as a tracer in fat deposition

Radiochlorine³⁸ was evaluated and found to be suitable for use as a tracer in studying the deposition of fat in porcinepanniculus adiposus tissue. Its short half-life makes its preparation from natural chlorine simple and inexpensive, and also minimizes long-term contamination problems, and its energetic beta and gamma rays makes its radio-assay simple and rapid. For swine, the threshhold level for a statistical counting accuracy of 1% was found to be approx 8 × 10⁻² mc/lb of live wt. The time required for the digestion, absorption, transport and deposition of statistically sufficient detectable radioactive material was 3 1/2 hr. The incorporation of radiochlorine³⁸ into lipid molecules does not appear to alter their normal metabolic pathways. Journal Series of The Pennsylvania Agricultural Experiment Station, Paper No. 2818.     

Systemic lupus erythematosus with a protein-losing enteropathy

Anasarca with pronounced hypoalbuminemia developed in a young woman 15 months after the onset of a mild, arthralgic type of systemic lupus erythematosus (SLE) without evidence of active nephritis. Investigation indicated a gastrointestinal rather than a renal site for protein loss. A full clinical remission was achieved with low-dose corticosteroid therapy.     

Acute pretreatment with pyrazole and ethanol: effects on glucose-induced changes in insulin and glucagon

Ethanol suppressed, in a dose-related manner, glucose-induced insulin (IRI) release and thus delayed the disappearance of glucose from the blood of rats. Pretreatment with pyrazole, an alcohol dehydrogenase inhibitor, exacerbated the effect of ethanol on IRI release, glucose tolerance and glucagon (IRG) release. These results suggest that ethanol produces glucose intolerance by inhibiting glucose-induced IRI release and by augmenting IRG release. Moreover, these findings indicate that ethanol does not have to be metabolized completely in order to produce these effects.     

Silicate-Containing Sodium Beta-Alumina Solid Electrolytes

Sodium beta-alumina solid electrolytes were prepared containing up to 7.5 wt% SiO₂ and their density, soda content, micro-structure, and ionic resistivity were studied. The resulting microstructures have glassy sodium ahminosilicate phases inhomogeneously distributed. The glassy phase collects preferentially at triple grain junctions, but occasionally penetrates along some grain boundaries as a thin layer (10 to 20 Å). Alpha-alumina is also present, especially with high silica content and when the samples are not protected with β-alumina powder during sintering. The total specific ionic resistivity follows a dependence on silicate content typical of 2-phase mixtures.