Previous investigations on the role of the polymerase in the synthesis of poly-3-hydroxybutyrate (PHB) are reviewed, and the results from earlier in vitro studies on the activity and selectivity of the polymerase of Alcaligenes eutrophus are discussed. In the present study the effect of glycerol on stabilizing the polymerase after purification and on eliminating the lag phase in in vitro polymerization reactions of 3-hydroxybutyl CoA (HBCoA), and 3-hydroxyvaleryl CoA (HVCoA) are described. K(M) values were determined for the activity of the polymerase with both HBCoA and HVCoA, and the rates of propagation for both monomers were estimated. With a racemic mixture of HBCoA, the enzyme polymerized only the [R] monomer.

Acyl Coenzyme A↗

PubMedDate not supplied

Extracellular degradation of medium chain length poly(beta-hydroxyalkanoates) by Comamonas sp.

The PHA-degrading isolate, strain P37C, was enriched from residential compost for its ability to hydrolyze the medium chain length PHA, poly(beta-hydroxyoctanoate) (PHO). It was subsequently found to grow on a wide range of PHAs, including both short chain length and medium chain length PHAs. The isolate was identified as belonging to the genus Comamonas. Strain P37C formed clear zones on poly(beta-hydroxybutyrate) (PHB), (PHO) and poly(beta-hydroxyphenylvalerate) (PHPV) overlay plates. PHA clear zone tubes were prepared using seven different kinds of PHAs, ranging from PHB with four-carbon repeating units, to poly(beta-hydroxyoctanoate-co-beta-hydroxyundecanoate) (PHOU) with 8- and 11-carbon repeating units. There was a direct correlation between PHA side chain length and rate of hydrolysis of the PHAs. A series of PHOUs containing varying percentages of unsaturated bonds were used to make a series of epoxidized PHOUs (PHOEs) with varying percentages of epoxy functions. Results of clear zone tube assays showed that these functionalized PHAs were all biodegradable by strain P37C, and there was no apparent correlation between rate of biodegradation and the proportion of functional groups in the PHAs. Biodegradability of these PHAs was verified using respirometry and enzyme assays. Cell-free supernatants containing activity toward PHAs were prepared, and strain P37C was shown to synthesize at least two distinct PHA depolymerases for the hydrolysis of SCL and MCL PHAs.

Carboxylic Ester Hydrolases↗

PubMedDate not supplied

Community development through faculty practice in a rural nurse-managed clinic.

This article describes a community-academic partnership that led to the development of a nurse-managed clinic (NMC) in 1996 in a rural Indiana area designated by the state as a medically underserved area (MUA) and a health professional shortage area (HPSA). Application of the community development model in faculty practice is described in relation to the clinic. The project is ongoing; lessons learned to date, which have implications for others involved in faculty practice, are described.

Community Health Centers↗

PubMedDate not supplied

Global regulation of expression of antifungal factors by a Pseudomonas fluorescens biological control strain.

The root-colonizing bacterium Pseudomonas fluorescens BL915 protects a variety of seedlings from damping-off disease caused by the fungal pathogen Rhizoctonia solani. Spontaneous pleiotropic mutants of P. fluorescens strain BL915 which fail to synthesize antifungal factors such as chitinase, cyanide, and pyrrolnitrin and exhibit altered colony morphology were isolated. Such mutants fail to inhibit the growth of R. solani in vitro, and their biological control capability is sharply reduced. We characterized a genomic DNA fragment from strain BL915 which, when introduced into these pleiotropic mutants, restored the lost functions, the wild-type colony morphology, and bio-control activity. DNA sequence analysis of the genomic fragment revealed the presence of genes homologous to those of numerous bacterial global regulatory systems and identified a cluster of genes identical in organization to the Escherichia coli gene cluster consisting of uvrY, uvrC, pgsA, and glyW. Coordinate biosynthesis of multiple antifungal products in some heterologous Pseudomonas strains in response to the introduction of the strain BL915 genomic fragment confirmed the regulatory nature of sequences contained on this fragment. Further genetic analysis indicated a gene homologous to response regulators of bacterial two-component systems was sufficient to complement the pleiotropic mutants and to activate antifungal genes in heterologous strains. Marker exchange of a truncated version of this gene into the P. fluorescens BL915 chromosome generated pleiotropic mutants indistinguishable from the original spontaneous mutants. Cloning and sequencing of the response regulator gene from several spontaneous mutants allowed identification of various nucleotide changes associated with the gene in such mutants.

Amino Acid Sequence↗

PubMedDate not supplied

Intravenous enzyme replacement therapy: better in home or hospital?

This article evaluates satisfaction with enzyme replacement therapy (ERT) at home and at hospital in adult patients with Fabry and Gaucher diseases. A questionnaire was developed and sent to 34 patients with Fabry disease who were receiving ERT with agalsidase alfa (Replagal) and to 49 patients with type I Gaucher disease who were receiving ERT with glucocerebrosidase (Cerezyme). Of the 45 returned questionnaires, 20 were from patients with Fabry disease and 25 from patients with Gaucher disease. Hospital treatment visits were reported as stressful by 18 patients (40%), whereas only 4 (9%) patients reported that home therapy was stressful. Both groups of patients adjusted well to receiving home-based therapy. Nearly all of the patients with Fabry disease (19 patients, 95%) and Gaucher disease (21 patients, 84%) preferred home-based therapy. Treatment in the home was reported as more comfortable, less stressful, more effective and had less impact on family life. Only 4 (9%) patients chose to continue receiving infusions in hospital. The majority of patients with Fabry disease and Gaucher disease found home-based therapy to be more convenient and less stressful than hospital-based therapy.

Adaptation, Psychological↗

PubMedDate not supplied

Remembrance day.

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Aged↗