Screening and characterization of microorganisms with glutaryl-7ADCA acylase activity

A screening of microorganisms producing glutaryl-7ADCA acylase, an enzyme able to hydrolyse glutaric acid selectively from glutaryl-3-deacetoxy-7-aminocephalosporanic acid (glutaryl-7ADCA), has been carried out in soil samples. Five microorganisms expressing acylase activity were isolated and classified as Bacillus cereus, Achromobacter xylosooxidans, Bacillus sp., Pseudomonas sp. and Pseudomonas paucimobilis. The screening was carried out by preparing enrichment cultures containing glutaryl-7-ADCA or cephalosporin C as the selective carbon source. Four model compounds (adipoyl-, glutamyl- and glutaryl-p-nitroanilide and glutarylcoumarin), mimicking the glutaryl-7ADCA beta-lactam moiety, were synthesized as substrates suitable for the rapid screening of the microorganisms (2500) isolated from the enrichment cultures. A total of 300 strains were active on the model substrates and only 5 displayed acylase activity on glutaryl-7ADCA. The fermentation parameters, such as pH and inducer concentration, for the optimal acylase expression and acylase specificity towards the model substrates were different for each strain.     

The effects of behavioral tasks on the in vitro phosphorylation of intermediate filament subunits of rat hippocampus are mediated by CaMKII and PKA

In the homodimeric hemoglobin from Scapharca, HbI, functional communication between the two heme groups is based on their direct structural linkage across the subunit interface through the heme propionates. The heme-protein interactions have been altered in deutero- and meso-HbI by substituting the vinyl groups at positions 2 and 4 of protoheme with hydrogen and ethyl groups, respectively. In meso-HbI the introduction of the ethyl groups in the heme pocket induces significant alterations in the conformation of the heme peripheral substituents, including the propionates, and in the structure of bound CO, as revealed by the resonance Raman spectra. The functional counterpart of these structural changes is the loss of cooperativity in carbon monoxide binding and in the rate of oxygen dissociation. Oxygen pulse and flash photolysis experiments indicate that meso-HbI is locked in the liganded conformation. It is postulated that the ethyl groups, which occupy a larger volume than vinyl ones, impair the ligand-linked movement of the heme relative to its pocket and in turn the expression of cooperativity. In deutero-HbI structural alterations have not been monitored. Functionally, cooperativity in the CO binding kinetics is increased as if hydrogen atoms at positions 2 and 4 permitted more marked movements of the heme than in the native protein.     

Prognostic significance of color Doppler findings in head and neck tumors

This summary of the practice parameters describes the assessment, differential diagnosis, and treatment of children, adolescents, and adults who present with symptoms of attention-deficit/hyperactivity disorder. The rationales for specific recommendations are based on a review of the scientific literature and clinical consensus which is contained in the complete document. Assessment includes clinical interviews with the child and parents and standardized rating scales from parent and teachers. Testing of intelligence and academic achievement is usually required. Comorbidity is common. The cornerstones of treatment are support and education of parents, appropriate school placement, and psychopharmacology. The primary medications are psychostimulants, but antidepressants and alpha-adrenergic agonists are used in special circumstances. Other treatments such as behavior modification, school consultation, family therapy, and group therapy address remaining symptoms.     

One hundred years of orthopedics in the Netherlands. I. Introduction

One hundred years ago, on 1 May 1898, the Netherlands Orthopaedic Association was founded. This was prompted by the view that general surgeons paid insufficient attention to the treatment of the locomotor system; they were permitted to join the new association, however, at any rate until 1947. It was especially in the last 30 years that orthopaedic surgery underwent major changes. The most striking novelty was arthroplastic surgery. There have also been developments in the treatment of spinal abnormalities, rheumatological surgery, sports medicine, oncology and traumatology.     

Instability of zeolite Y supported cobalt sulfide hydrotreating catalysts in the absence of H2S

Ion exchanged CoNaY was sulfided at 473 and 673 K and subsequently heated in He at 673 and 773 K. The resulting samples were characterized by means of overall sulfur analysis, temperature programmed Ar treatment and Fourier transform infrared spectroscopy. It was shown that during He flushing at sufficiently high temperature a protolysis reaction occurs resulting in the decomposition of Co sulfide into Co²⁺ ions and H₂S.     

Hip impact velocities and body configurations for voluntary falls from standing height

OBJECTIVE: To determine prevalence of various pheno- and genotypes of Serpulina sp in young pigs in relation to diarrhea and feed medication in Swedish pig-rearing herds. DESIGN: Isolation of spirochetes. Phenotypical and genotypical classification. SAMPLE POPULATION: Young pigs (n = 358) in 19 pigrearing herds. PROCEDURE: Serpulina isolates were classified according to a biochemical scheme based on hemolysis, indole production, hippurate hydrolysis, and alpha-galactosidase, alpha-glucosidase, and beta-glucosidase activities. The 16S rRNA sequences for 10 of the field strains and 2 type strains of Serpulina spp were aligned and compared. Minimum inhibitory concentrations of olaquindox for 9 of the strains were determined. RESULTS: Weakly beta-hemolytic intestinal spirochetes (WBHIS) were isolated from 17 of the herds and 65% of the samples. More than 1 phenotype of WBHIS was found in 12 of the 19 herds. S hyodysenteriae was not isolated in any of the herds. Hippurate-positive WBHIS were isolated in 6 of 7 herds affected by diarrhea, but in only 1 of 8 herds without diarrhea. Hippurate-positive strains were closely related to the pathogenic strain P43 if judged from sequence comparisons. Strains with the same biochemical profile isolated within a herd had identical sequences, but when isolated from different herds, sequence differences were observed. The prevalence of WBHIS was reduced in herds medicated with olaquindox. Investigated field strains had minimum inhibitory concentration values < or = 1 microgram/ml for olaquindox. CONCLUSION: The presence of WBHIS, with the ability to hydrolyze hippurate, was related to diarrhea in pig herds. CLINICAL RELEVANCE: Potentially pathogenic WBHIS can be distinguished from nonpathogenic strains by the hippurate hydrolysis test.