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Biomedical subjects

E Glenn

Publications and source records attributed to E Glenn.

8 recordsLinked to original sources

A second dose of a CFTR cDNA-liposome complex is as effective as the first dose in restoring cAMP-dependent chloride secretion to null CF mice trachea.

Phase I clinical trials have provided encouraging data suggesting that gene transfer could provide a treatment for cystic fibrosis (CF). However, for all the current viral and nonviral vectors used to deliver the cystic fibrosis transmembrane conductance regulator (CFTR) gene, the duration of CFTR expression is limited, necessitating a repeat dosing regimen to provide a long-term treatment. This study was performed to determine whether a second delivery of a CFTR cDNA-liposome complex could result in a similar level of functional CFTR expression observed after a single delivery and to assess whether the deliveries produced adverse inflammatory responses. CFTR functional expression was assessed by short circuit current measurements of tracheas taken from CF null mice (Cftrtm1Cam) treated with a CFTR cDNA-liposome complex in the upper airways. Mice receiving two deliveries of this complex, the second after the response to the first had declined, showed cAMP-stimulated chloride currents which were not significantly different from normal tracheas or tissues assayed after a single dose of the complex. This double treatment was well tolerated with no discernible inflammation of lung tissue.

Animals↗

[Microbiologic depuration of Anadara tuberculosa (Mollusca: Arcidae)].

In Costa Rica the mollusk Anadara tuberculosa represents a risk for human health due to the contamination of the growing waters and the fact that its is consumed raw. The families depending on the income obtained through commercialization of these animals have a low education and economic status. Therefore, it is of great importance to develop and evaluate simple methods of depuration that could be easily used by these families to make these mollusks safe for consumption. Bottles containing 11 of saline solution (25g/l) were prepared in duplicates to test the bactericidal effect of acetic acid. The solution in each bottle was adjusted to ph 4.5, 5.0 or 5.5 or held at ph of 7.0 or 8.0 for the controls. The solution in each bottle was then inoculated with approximately 1 X 104 cfu/ml of coliforms. Counts of coliforms were determined for each bottle 0, 1, 2, 4 and 8 hours after inoculation. For the depuration studies, specimens with diameters ranging from 4.0 to 4.5 cm were collected from a harvester at the estuary of Puntarenas, Gulf of Nicoya. Fifty specimens each were depurated in separate tanks containing 25 1 of oxygenated saline solution adjusted with acetic acid to an initial ph of 4.5 (treatment) or non adjusted ph of 8.0 (control). Counts of Enterobacteriaceae were determined, in duplicates, every 12 hr for 48 hr. An additional fifty animals were depurated using the defined method and tested to determine if they met international standards of microbiological quality for aerobic plate count, Enterobacteriaceae count, Escherichia coli count and presence of Salmonella. A sensory evaluation using a triangle test was performed to compare a typical dish prepared with depurated or non-depurated animals. A significant coliform reduction was determined in a saline solution (25 g/l) at a pH range of 4.5 to 5.5. This reduction, during 8 hr, was higher in the acid treatments compared to the controls. During depuration, the elimination of Enterobacteriaceae bacteria was faster when acetic was used (initial ph = 4.5) than when it was not. This elimination was more important the first 24 hr, time defined as adequate for the application of the method. The method has the advantage of transforming the bivalve in a product that is safe for human consumption, since it guarantees that the international standards of microbiological quality, for raw and depurated mollusks, are reached. On the other hand, the sensory qualities of a typical dish prepared with depurated animals are not affected by the method, which can be easily implemented and applied by the people that work in the extraction of this mollusk.

Acetic Acid↗

Two Penicillium camembertii mutants affected in the production of cyclopiazonic acid.

Penicillium camembertii was mutated and screened for cyclopiazonic acid-negative mutants. With a simple and rapid mini-extraction method for detection of cyclopiazonic acid production, we were able to isolate two strains which were affected in the production of this metabolite. One strain had completely lost the ability to synthesize detectable amounts of this secondary metabolite, whereas the other mutant produced 50 to 100 times less cyclopiazonic acid than the wild type. Also, the former strain had a changed morphology compared with the wild type. This morphological alteration appears to be coupled to the inability to produce cyclopiazonic acid because morphological revertants were able to synthesize cyclopiazonic acid to a level comparable to the wild type. The second mutant accumulated a new metabolite which was detectable by two-dimensional thin-layer chromatography. This new metabolite, however, appears not to be a direct precursor of cyclopiazonic acid.

Genes, Fungal↗

Properties and subcellular distribution of two partially purified ornithine transcarbamoylases in cell suspensions of sugarcane.

The spatially separated forms of ornithine transcarbamoylase (EC 2.1.3.3) of different molecular weights coexist in sugarcane (Saccharum sp.). The smaller form of the enzyme (mol wt 79,000) appears to be cytoplasmic, while a larger form (mol wt 224,000) sedimented with mitochondria. The Km of the cytoplasmic enzyme for ornithine was 3.11 mm, while the enzyme in the mitochondrial fraction had a Km of 0.50 mm for this substrate; both enzymes had similar affinity for carbamoyl phosphate (0.12 mm). Characteristics of the smaller ornithine transcarbamoylase are in keeping with a predominantly catabolic function, those of the enzyme which sediments with mitochondria, with an anabolic function. Only the mitochondrial enzyme was regulated in vivo by exogenous arginine.

Journal Article↗