PubMed Health⌕ Search

Biomedical subjects

A Koning

Publications and source records attributed to A Koning.

10 recordsLinked to original sources
PubMed1996

In vivo examination of membrane protein localization and degradation with green fluorescent protein.

To test the utility of green fluorescent protein (GFP) as an in vivo reporter protein when fused to a membrane domain, we made a fusion protein between yeast hydroxymethylglutaryl-CoA reductase and GFP. Fusion proteins displayed spatial localization and regulated degradation consistent with the native hydroxymethylglutaryl-CoA reductase proteins. Thus, GFP should be useful in the study of both membrane protein localization and protein degradation in vivo.

Base Sequence↗
PubMed1993

Patchwork access. Primary care in EDs on the rise.

It's been long known that EDs in the nation's largest cities routinely provide non-emergent primary care. But a new study by the AHA and several allied hospital associations has found that a very high proportion of ED visits in each of the four communities studied could have been handled outside the ED.

American Hospital Association↗
PubMed1992

Arrest of embryo development in Brassica napus mediated by modified Pseudomonas aeruginosa exotoxin A.

Intracellularly expressed cytotoxins are useful tools both to study the action of plant regulatory sequences in transgenic plants and to modify plant phenotype. We have engineered a low mammalian toxicity derivative of Pseudomonas aeruginosa exotoxin A for intracellular expression in plant cells by fusing the ADP ribosylating domain of the exotoxin gene to plant regulatory sequences. The efficacy of exotoxin A on plant cells was demonstrated by transient expression of the modified exotoxin gene in tobacco protoplasts: the exotoxin gene inhibited the expression of a co-electroporated beta-glucuronidase gene. An exotoxin with an introduced frameshift mutation was also effective at inhibiting beta-glucuronidase expression in the transient assay; the activity of the frameshifted gene was presumably a result of frameshifting during translation or initiation of translation at a codon other than AUG. When fused to napin regulatory sequences, the exotoxin gene specifically arrested embryo development in the seeds of transgenic Brassica napus plants concomitant with the onset of napin expression. The napin/exotoxin chimeric gene did not have the same pattern of expression in tobacco as in B. napus; in addition to exhibiting an inhibition of seed development, the transgenic tobacco plants were male-sterile.

2S Albumins, Plant↗
PubMed1988

The avian erythroblastosis virus erbA oncogene encodes a DNA-binding protein exhibiting distinct nuclear and cytoplasmic subcellular localizations.

The protein product of the v-erbA oncogene of avian erythroblastosis virus was analyzed by use of site-specific antisera. The v-erbA protein was found to exist in distinct nuclear and cytoplasmic forms. Both nuclear and cytoplasmic species of the v-erbA protein were capable of binding to DNA, a property predicted based on the structural relatedness the v-erbA polypeptide shares with the thyroid and steroid hormone receptors. A mutation within the v-erbA coding region which inhibited DNA binding and nuclear localization also inhibited the ability of the v-erbA protein to potentiate erythroid transformation, consistent with a model of the v-erbA protein as a transcriptional regulator.

Alpharetrovirus↗
PubMed1988

Genetic dissection of functional domains within the avian erythroblastosis virus v-erbA oncogene.

The avian erythroblastosis virus v-erbA locus potentiates the oncogenic transformation of erythroid and fibroblast cells and is derived from a host cell gene encoding a thyroid hormone receptor. We report here the use of site-directed mutagenesis to identify and characterize functional domains within the v-erbA protein. Genetic lesions introduced into a putative hinge region or at the extreme C-terminus of the v-erbA coding domain had no significant effect on the biological activity of this polypeptide. In contrast, mutations introduced within the cysteine-lysine-arginine-rich center of the v-erbA coding region, a DNA-binding domain in the thyroid and steroid hormone receptors, abolished or severely compromised the ability of the viral protein to function. Our results suggest that the mechanism of action of the v-erbA protein in establishing the neoplastic phenotype is closely related to its ability to interact with DNA, presumably thereby altering expression of host target genes by either mimicking or interfering with the action of the normal c-erbA gene product.

Alpharetrovirus↗
PubMedDate not supplied

[Critical analysis of the evolution of commercial preparations for enteral nutrition during 1988-1996].

Enteral nutrition is a form of nutritional support that is continually growing and expanding, and within this area especially the enteral preparations or formulae. The object of the present is to analyze the evolution of the commercially available nutritionally complete enteral preparations between 1988 and 1997, illustrating the variations that have occurred both from the quantitative and form the qualitative points of view. A progressive increase is seen in the absolute number of available enteral formulae, with the increase in both polymeric formulae with dietary fiber, and that of formulae designed for specific diseases being significant (p < 0.05). The standard polymeric formulae and the oligomeric formulae decrease, but not in a significant manner. There is a special discussion or the characteristic and the usefulness of the polymeric formulae with dietary fiber ad the formulae designed especially for specific diseases. The clinical efficacy of most of these special formulae is controversial, with there not being sufficient objective clinical evidence at present that justifies their routine use.

Dietary Fiber↗
PubMedDate not supplied

[Nutritional management of radiation-induced enteritis: apropos of a case].

We present a case of a 46-year-old woman who is hospitalized in March of 1997 for a picture of severe mixed malnutrition. We describe the clinical history since the diagnosis of an endometrium carcinoma in 1995, treated with radiation therapy, with the aim of determining the etiology of the severe malnutrition picture, as well as the different complications she presented in the course of her hospitalization that justify the decisions made in the choice of the nutritional support.

Crohn Disease↗
PubMedDate not supplied

[Complications of enteral nutrition at home. Results of a multicentre trial].

AIM: In spite of the increasing number of home enteral nutrition (HEN) patients, only few articles had reported the frequency of complications related to this treatment. Our multicentric study analyzes the HEN complications in relation to access device and time of treatment. METHOD: 92 HEN patients from 8 hospitals were randomly selected. Patients were distributed in relation to the time of treatment and access device (nasogastric tube and percutaneous or surgical gastrostomies). After an educational program, they were filled in an initial questionnaire and repeated it the days 15 and 30. They received a mean of 1650 Kcal of enteral solution. A total of 2760 HEN prospective days were analyzed. RESULTS: In prospective study 42% of patients had some complication (112 episodes). The most frequent were gastrointestinal (55%) and mechanical (29%); 0.16 complications of patient-year were registered. The most common complications were: extraction (15%), constipation (13%), vomiting (12%) and diarrhoea (10%). The gastrostomy group had more gastrointestinal complications. In retrospective evaluation, percutaneous gastrostomy group had the lowest ratio of complications and nasogastric tube group required more tube replacements (4 vs 2) and had 1.96 episodes/patient (percutaneous group 1.85 and surgical gastrostomy 3.1 episodes/patient). CONCLUSION: HEN is safe with low incidence of complications. An adequate educational program is very important and we expect, in the future, to establish an proper National Home Care System.

Adult↗
PubMedDate not supplied

[Fiber in enteral nutrition: systematic review of the literature].

UNLABELLED: It has been suggested that adding fibre to enteral nutrition (EN) formulas may achieve a normalization of the gastrointestinal tract's functions by reducing the incidence of diarrhoea and constipation. However, this supposition is based on the demonstrated effect of fibre in natural feeding. There have so far been no firm recommendations on the use, amount or type of fibre that is most advisable in EN. GOAL: To establish the scientific evidence existing on the benefits gained by adding fibre to EN formulas compared with the use of fibre-free formulas. MATERIAL AND METHODS: Bibliographical search on PubMed, on the register of Randomized Prospective Trials (RPT) of the Cochrane Library and manual search. INCLUSION CRITERIA: RPT comparing fibre-free formulas with isocaloric ad isonitrogen formulas containing fibre in total EN. Four independent reviewers revised the references selected. The data were analyzed using the RevMan 4.1 programme from the Cochrane Library. RESULTS: Of 286 references, 25 fulfilled the inclusion criteria. The data were grouped by population and outcome variable. The addition of fermentable fibre to the EN formulas tends to reduce the incidence of diarrhoea in critically-ill and post-surgery patients (OR = 0.66; 95% CI 0.46-0.95; p = 0.19). The use of formulas with insoluble fibre seems to increase the frequency of depositions and reduce the need for laxatives in immobilized patients receiving long-term EN but the data are insufficient. In people with normal gastrointestinal functions, the frequency of depositions is similar when using formulas with and without fibre (DPM = -0.97; 95% CI -0.12-[-0.02]; p < 0.0001). CONCLUSION: There is currently insufficient evidence to recommend the systematic use of formulas containing fibre in total EN. However, in critically-ill and post-surgery patients, the use of formulas with fermentable fibre tends to reduce the incidence of diarrhoea. Although information is still lacking. The formulas with insoluble fibre seem to diminish constipation in chronic EN, whereas in other situations where the digestive system is working appropriately, no benefit has been shown. It is necessary to increase the number and quality of these trials in order to be able to establish firm recommendations on the use of EN formulas containing fibre.

Dietary Fiber↗