Biomedical subjects

Maria Olsson

Publications and source records attributed to Maria Olsson.

5 recordsLinked to original sources

PubMed2004

Rat intestinal ceramidase: purification, properties, and physiological relevance.

Neutral ceramidase activity has previously been identified in the intestinal mucosa and gut lumen and postulated to be important in the digestion of sphingolipids. It is found throughout the intestine but has never been fully characterized. We have purified rat intestinal neutral ceramidase from an eluate obtained by perfusing the intestinal lumen with 0.9% NaCl and 3 mM sodium taurodeoxycholate. Using a combination of acetone precipitation and ion-exchange, hydrophobic-interaction, and gel chromatographies, we obtained a homogenous enzyme protein with a molecular mass of approximately 116 kDa. The enzyme acts on both [14)]octanoyl- and [14C]palmitoyl-sphingosine in the presence of glycocholic and taurocholic acid and the bile salt analog 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate but is inhibited by 2 mM or more of other bile salts. It is a glycosylated protein stable to trypsin and chymotrypsin exposure, is not influenced by Ca2+, Mg2+, or Mn2+, and is inhibited by Zn2+ and Cu2+. Mass fragmentographic analysis identified 12 fragments covering 17.5% of the sequence for neutral/alkaline ceramidase 2 purified (Mitsutake S, Tani M, Okino N, Mori K, Ichinose S, Omori A, Iida H, Nakamura T, and Ito M. J Biol Chem 276: 26249-262459, 2001) from rat kidney and located in apical membrane of renal tubular cells. Intestinal and kidney ceramidases also have similar molecular mass and ion dependence. Intestinal ceramidase thus is a neutral ceramidase 2 released by bile salts and resistant to pancreatic proteases. It is well suited to metabolize ceramide formed from dietary and brush border sphingolipids to generate other bioactive sphingolipid messengers.

Amidohydrolases↗

PubMed2004

Methodology for perceptual assessment of speech in patients with cleft palate: a critical review of the literature.

OBJECTIVE AND DESIGN: This review of 88 articles in three international journals was undertaken for the purpose of investigating the methodology for perceptual speech assessment in patients with cleft palate. The articles were published between 1980 and 2000 in the Cleft Palate-Craniofacial Journal, the International Journal of Language and Communication Disorders, and Folia Phoniatrica et Logopaedica. RESULTS AND CONCLUSIONS: The majority of articles (76) were published in the Cleft Palate-Craniofacial Journal, with an increase in articles during the 1990s and 2000. Information about measures or variables was clearly given in all articles. However, the review raises several major concerns regarding method for collection and documentation of data and method for measurement. The most distressing findings were the use of a cross-sectional design in studies of few patients with large age ranges and different types of clefts, the use of highly variable speech samples, and the lack of information about listeners and on reliability. It is hoped that ongoing national and international collaborative efforts to standardize procedures for collection and analysis of perceptual data will help to eliminate such concerns and thus make comparison of published results possible in the future.

Cleft Palate↗

PubMed2003

Benzene emitted from glowing charcoal.

Benzene was assessed as the predominant aromatic compound emitted from glowing charcoal and firewood embers. Concentrations measured above charcoal used for grilling exceeded 10 mg m(-3) at a 5% carbon dioxide level. Charcoal with a high carbon content released less benzene. Glowing wood pellets emitted less benzene than glowing firewood remainders. The emissions of ethene and propene relative to benzene were low for commercial charcoal and wood-pellet embers, but high for firewood ember. The proportions of methylbenzene and naphthalene from charcoal were typically only 10% relative to benzene, and those of benzofuran, dibenzofuran and benzonitrile were typically below 5%. The polycyclic aromatic hydrocarbon (PAH) indicator phenanthrene was below the 1% level. Adsorbent sampling and GC-MS were used for assessing all the aromatic compounds. Earlier studies of charcoal emissions have focused on carbon monoxide, PAH and dioxins. It is concluded that the carcinogenic benzene may be an even more severe health hazard to be addressed by exposure-decreasing measures.

Air Pollutants↗

PubMed2001

Epstein-Barr virus nuclear antigen 5 interacts with HAX-1, a possible component of the B-cell receptor signalling pathway.

Using a yeast two-hybrid screen of a B-cell cDNA library with an Epstein-Barr nuclear antigen 5 (EBNA5) molecule containing seven repeats of the W(1)W(2) domain as bait, we have isolated the EBNA5-interacting protein HAX-1. HAX-1 has previously been shown to associate with HS1, a protein specifically expressed in cells of the haematopoietic lineage, and is thought to be involved in signal transduction in B-cells. Immunofluorescence experiments showed that HAX-1 co-localized with the hsp60 protein that is associated with the mitochondria in the cell cytoplasm. Pull down experiments with a fusion protein between glutathione S-transferase and the seven copy repeat EBNA5 synthesized in bacteria and in yeast cells confirmed that HAX-1 can interact with EBNA5 in vitro. Conventionally, EBNA5 is regarded as a nuclear protein. However, we show here that the smallest EBNA5 species, composed of the unique Y domain and only one copy of the W(1)W(2) repeat domain, like HAX-1, co-localizes with the mitochondrial hsp60 protein in the B-cell cytoplasm. Furthermore, immunoprecipitation experiments demonstrate that the single repeat EBNA5 associates with HAX-1 in transfected B-lymphoblastoid cells.

Adaptor Proteins, Signal Transducing↗

PubMedDate not supplied

[Nasal obstruction].

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Diagnosis, Differential↗