Different alpha-adrenoceptors mediate migration of vascular smooth muscle cells and adventitial fibroblasts in vitro

Norepinephrine directly induces growth of the vascular wall, which may involve not only proliferation of smooth muscle cells (SMCs) and adventitial fibroblasts (AFBs) but also augmentation of their migration. To test this hypothesis, growth-arrested SMCs and AFBs from rat aorta were exposed to norepinephrine. Norepinephrine caused dose-dependent migration of both cell types that was dependent on chemotaxis. In contrast, platelet-derived growth factor (PDGF)-BB, used as a positive control, stimulated both chemotaxis and chemokinesis. Only alpha(1D)-adrenoceptors (AR) and alpha(2)-AR antagonists inhibited norepinephrine migration of SMCs, whereas norepinephrine migration of AFBs was only inhibited by alpha(1A)-AR and alpha(1B)-AR antagonists; beta-AR blockade was without effect. Norepinephrine and PDGF-BB were additive for AFB, but not SMC, migration. Stimulation of migration was reversed at high norepinephrine concentrations (10 microM); this inhibition was mediated by alpha(2)- and beta-ARs in AFBs but not in SMCs. Thus norepinephrine induces migration of SMCs and AFBs via different alpha-ARs. This action may participate in wall remodeling and norepinephrine potentiation of injury-induced intimal lesion growth.     

Stereoselective anti-Prelog reduction of ketones by whole cells of Comamonas testosteroni in a ‘substrate-coupled’ approach

Lyophilized cells of the open accessible bacterium Comamonas testosteroni DSM 1455 proved to be an excellent catalyst for the asymmetric reduction of different α-azido, α-bromo, and α-nitro ketones at elevated substrate concentrations (16 g/L) in a ‘substrate-coupled’ approach using 20% (v/v) of 2-propanol as hydrogen donor. Excellent anti-Prelog stereoselectivity was obtained, which is less common found in nature.     

Structural and Mechanistic Analysis of the Choline Sulfatase from Sinorhizobium melliloti: A Class I Sulfatase Specific for an Alkyl Sulfate Ester

Hydrolysis of organic sulfate esters proceeds by two distinct mechanisms, water attacking at either sulfur (S–O bond cleavage) or carbon (C–O bond cleavage). In primary and secondary alkyl sulfates, attack at carbon is favored, whereas in aromatic sulfates and sulfated sugars, attack at sulfur is preferred. This mechanistic distinction is mirrored in the classification of enzymes that catalyze sulfate ester hydrolysis: arylsulfatases (ASs) catalyze S–O cleavage in sulfate sugars and arylsulfates, and alkyl sulfatases break the C–O bond of alkyl sulfates. Sinorhizobium meliloti choline sulfatase (SmCS) efficiently catalyzes the hydrolysis of alkyl sulfate choline-O-sulfate (k_cat/K_M = 4.8 × 10³ s^? 1 M^? 1) as well as arylsulfate 4-nitrophenyl sulfate (k_cat/K_M = 12 s^? 1 M^? 1). Its 2.8-Å resolution X-ray structure shows a buried, largely hydrophobic active site in which a conserved glutamate (Glu386) plays a role in recognition of the quaternary ammonium group of the choline substrate. SmCS structurally resembles members of the alkaline phosphatase superfamily, being most closely related to dimeric ASs and tetrameric phosphonate monoester hydrolases. Although > 70% of the amino acids between protomers align structurally (RMSDs 1.79–1.99 Å), the oligomeric structures show distinctly different packing and protomer–protomer interfaces. The latter also play an important role in active site formation. Mutagenesis of the conserved active site residues typical for ASs, H₂¹⁸O-labeling studies and the observation of catalytically promiscuous behavior toward phosphoesters confirm the close relation to alkaline phosphatase superfamily members and suggest that SmCS is an AS that catalyzes S–O cleavage in alkyl sulfate esters with extreme catalytic proficiency.     

Zinc uptake by corn as affected by vesicular-arbuscular mycorrhizae

Pot-grown mycorrhizal and non-mycorrhizal sweet corn were grown in a low Zn soil. All treatments received a complete nutrient solution with or without Zn. Treatments were harvested sequentially to detemine temporal mycorrhizal effects on: (a) tissue and water soluble Zn and (b) differential uptake of P and Zn. Plants grown with supplemental Zn had greater growth and Zn tissue concentration than those not receiving Zn. With no supplemental Zn, mycorrhizal treatments had greater growth and Zn concentration than non-mycorrhizal treatments. There was no indication of nutrient interaction between Zn and P. Over the range of tissue Zn found, there appeared to be no advantage to water soluble Zn analysis over total Zn in assessing plant Zn status.     

Assessment of Patient Empowerment - A Systematic Review of Measures

BackgroundPatient empowerment has gained considerable importance but uncertainty remains about the best way to define and measure it. The validity of empirical findings depends on the quality of measures used. This systematic review aims to provide an overview of studies assessing psychometric properties of questionnaires purporting to capture patient empowerment, evaluate the methodological quality of these studies and assess the psychometric properties of measures identified.MethodsElectronic searches in five databases were combined with reference tracking of included articles. Peer-reviewed articles reporting psychometric testing of empowerment measures for adult patients in French, German, English, Portuguese and Spanish were included. Study characteristics, constructs operationalised and psychometric properties were extracted. The quality of study design, methods and reporting was assessed using the COSMIN checklist. The quality of psychometric properties was assessed using Terwee’s 2007 criteria.Findings30 studies on 19 measures were included. Six measures are generic, while 13 were developed for a specific condition (N=4) or specialty (N=9). Most studies tested measures in English (N=17) or Swedish (N=6). Sample sizes of included studies varied from N=35 to N=8261. A range of patient empowerment constructs was operationalised in included measures. These were classified into four domains: patient states, experiences and capacities; patient actions and behaviours; patient self-determination within the healthcare relationship and patient skills development. Quality assessment revealed several flaws in methodological study quality with COSMIN scores mainly fair or poor. The overall quality of psychometric properties of included measures was intermediate to positive. Certain psychometric properties were not tested for most measures.DiscussionFindings provide a basis from which to develop consensus on a core set of patient empowerment constructs and for further work to develop a (set of) appropriately validated measure(s) to capture this. The methodological quality of psychometric studies could be improved by adhering to published quality criteria.     

P59, an hsp 90-binding protein. Cloning and sequencing of its cDNA and preparation of a peptide-directed polyclonal antibody.

The primary sequence of the rabbit liver cDNA coding for protein p59 has been determined. The protein binds to the 90-kDa heat shock protein (hsp 90) and is associated with it, including when hsp 90 participates in hetero-oligomeric complexes of untransformed mammalian steroid receptors that sediment at 8-10 S. The cloned cDNA codes for an open reading frame of 458 amino acids defining a yet unknown protein. However, 55% amino acid homology to peptidyl-prolyl isomerase is found between amino acids 41 and 137, suggesting rotamase activity for p59, which speculatively may apply to bound hsp 90 and thus be implied in the intracellular trafficking of hetero-oligomeric forms of steroid hormone receptors. A polyclonal antibody derived from the COOH-terminal peptide 441-458 demonstrates a good affinity for rabbit, rat, and human p59 protein. It interacts with at least one epitope, available in 8-10 S untransformed steroid receptor complexes and different from that recognized by the monoclonal antibody KN382/EC-1.     

Experimental Infection of the Cotton Rat Sigmodon hispidus with Rickettsia rickettsii

Studies of experimental infection of the cotton rat, Sigmodon hispidus, with the virulent Sheila Smith (R type) and the avirulent Si 7 (U type) strains of Rickettsia rickettsii were undertaken to evaluate the role of this native wild mammal in the ecology of Rocky Mountain spotted fever. The Sheila Smith strain, which was highly lethal for guinea pigs, was nonpathogenic for cotton rats. Serial passage of the R-type strain in the cotton rat did not alter the virulence of the agent for cotton rats or guinea pigs. The U-type strain, which was originally recovered from a wild cotton rat, could not be maintained beyond the first passage in this animal host. Rickettsemia in the cotton rat occurred over a 24-hr period after inoculation of the virulent strain but was detected only 1 hr after inoculation of the avirulent strain. The short period of rickettsemia suggests that the cotton rat probably is not an important reservoir of R. rickettsii. Specific complement-fixing antibodies developed rapidly after infection with either strain, but the antibodies evoked by the R strain attained higher titers and persisted longer. Cotton rats previously infected with the Sheila Smith strain developed rickettsemia after reinfection with the same strain, even though relatively high levels of antibody were still present.