Oncostatin M receptor-beta mutations underlie familial primary localized cutaneous amyloidosis

Familial primary localized cutaneous amyloidosis (FPLCA) is an autosomal-dominant disorder associated with chronic skin itching and deposition of epidermal keratin filament-associated amyloid material in the dermis. FPLCA has been mapped to 5p13.1–q11.2, and by candidate gene analysis, we identified missense mutations in the OSMR gene, encoding oncostatin M-specific receptor β (OSMRβ), in three families. OSMRβ is a component of the oncostatin M (OSM) type II receptor and the interleukin (IL)-31 receptor, and cultured FPLCA keratinocytes showed reduced activation of Jak/STAT, MAPK, and PI3K/Akt pathways after OSM or IL-31 cytokine stimulation. The pathogenic amino acid substitutions are located within the extracellular fibronectin type III-like (FNIII) domains, regions critical for receptor dimerization and function. OSM and IL-31 signaling have been implicated in keratinocyte cell proliferation, differentiation, apoptosis, and inflammation, but our OSMR data in individuals with FPLCA represent the first human germline mutations in this cytokine receptor complex and provide new insight into mechanisms of skin itching.     

Identification and Characterization of Lactococcal-Prophage-Carried Superinfection Exclusion Genes

Superinfection exclusion (Sie) proteins are prophage-encoded phage resistance systems. In this study, genes encoding Sie systems were identified on the genomes of Lactococcus lactis subsp. cremoris MG1363 and L. lactis subsp. lactis IL1403. These Sie systems are genetically distinct and yet were shown to act specifically against a particular subset of the 936 phage group. Each of the systems allows normal phage adsorption while affecting plasmid transduction and intracellular phage DNA replication, which points to the blocking of phage DNA injection as their common mode of action. Sie-specifying genes found on the MG1363 prophages are also present in various lactococcal strains, whereas the prophage-encoded Sie systems of IL1403 do not appear to be as widely disseminated.     

Assessing the potential for zinc and cadmium phytoremediation with the hyperaccumulator Thlaspi caerulescens

Thlaspi caerulescens is a Zn and Cd hyperaccumulator, and has been tested for its phytoremediation potential. In this paper we examine the relationships between the concentrations of Zn and Cd in soil and in T. caerulescens shoots, and calculate the rates of Zn and Cd extraction from soil. Using published data from field surveys, field and pot experiments, we show that the concentrations of Zn and Cd in the shoots correlate with the concentrations of Zn and Cd in soils in a log-linear fashion over three orders of magnitude. There is little systematic difference between different populations of T. caerulescens in the relationship between soil and plant Zn concentrations. In contrast, populations from southern France are far superior to those from other regions in Cd accumulation. Bioaccumulation factors (plant to soil concentration ratio) for Zn and Cd decrease log-linearly with soil metal concentration. Model calculations show that phytoremediation using T. caerulescens is feasible when soil is only moderately contaminated with Zn and Cd, and the phytoremediation potential is better for Cd than for Zn if the populations from southern France are used. Recent progress in the understanding of the mechanisms of Zn and Cd uptake by T. caerulescens is also reviewed.     

Cryomicroscope investigation and thermodynamic modeling of the freezing of unfertilized hamster ova

Thermodynamic computer modeling was used to predict the freezing response of single-celled unfertilized hamster ova. The cell membrane transport characteristics were investigated, using a microscope diffusion chamber system. The mean osmotically inactive cell volume was determined to be 21.6% of the initial cell volume. An overall mean value of 0.8 +/- 0.1 micron3/micron2.min.atm (= 18 +/- 2.5 micron/sec) was determined for the membrane hydraulic coefficient, Lp. The effect of the extracellular solute concentration on Lp was determined at room temperature (approximately 23 degrees C). A thermodynamic computer model was used to predict the cell response to freezing. The predicted response was compared to the actual volumetric response observed during freezing on a temperature-controlled cryomicroscope conduction stage. The effect of the cooling rate on the nucleation temperature of unprotected ova and protected ova suspended in a 1.5 M DMSO solution was investigated. Overall mean nucleation temperatures of -13 and -57.1 degrees C were observed for unprotected and protected ova, respectively, where the mean nucleation temperature for protected ova was strongly cooling rate dependent.     

A plate assay for the detection of organophosphonate mineralization by environmental bacteria,and its modification as an activity stain for identification of the carbon — phosphorus bond cleavage enzyme phosphonoacetate hydrolase

Summary A replica plate screening technique,based on the acid molybdate assay for detection of phosphate,has been developed to permit the detection of microorganisms capable of mineralizing organophosphonates. The method was further adapted as the basis of an activity stain for the detection of the carbon - phosphorus bond cleavage enzyme phosphonoacetate hydrolase in PAGE gels.     

Photobleaching. A novel fluorescence method for diffusion studies in lipid system.

(1) The fluorescent molecular 12(9-anthroyloxy)-stearic acid dimerises on irradiation with light of 366 nm wavelength. (2) The dimer is nonfluorescent and can be reconverted to the parent compound by irradiation at 254 nm. (3) Kinetic analysis suggests that the dimerisation proceeds by a diffusion-limited second order mechanism in many solvents. (4) Anomalously high rates seen in other systems can be attributed to localised high concentration regions (clusters) of the fluorescent molecule. (5) The analysis has been extended to oriented lipid bilayers and the results suggest that below the gel-liquid crystalline transition temperature the 12(9-anthroyloxy)-stearic acid is excluded by the lipid matrix and forms regions of localised high concentration. (6) In fluid lipid the results suggest an isotropic distribution of the probe. Calculated diffusion coefficients correspond to those found by other techniques.