Protein profiles of CCL5, HPGDS, and NPSR1 in plasma reveal association with childhood asthma.

Asthma is a common chronic childhood disease with many different phenotypes that need to be identified. We analyzed a broad range of plasma proteins in children with well-characterized asthma phenotypes to identify potential markers of childhood asthma. Using an affinity proteomics approach, plasma levels of 362 proteins covered by antibodies from the Human Protein Atlas were investigated in a total of 154 children with persistent or intermittent asthma and controls. After screening, chemokine ligand 5 (CCL5) hematopoietic prostaglandin D synthase (HPGDS) and neuropeptide S receptor 1 (NPSR1) were selected for further investigation. Significantly lower levels of both CCL5 and HPGDS were found in children with persistent asthma, while NPSR1 was found at higher levels in children with mild intermittent asthma compared to healthy controls. In addition, the protein levels were investigated in another respiratory disease, sarcoidosis, showing significantly higher NPSR1 levels in sera from sarcoidosis patients compared to healthy controls. Immunohistochemical staining of healthy tissues revealed high cytoplasmic expression of HPGDS in mast cells, present in stroma of both airway epithelia, lung as well as in other organs. High expression of NPSR1 was observed in neuroendocrine tissues, while no expression was observed in airway epithelia or lung. In conclusion, we have utilized a broad-scaled affinity proteomics approach to identify three proteins with altered plasma levels in asthmatic children, representing one of the first evaluations of HPGDS and NPSR1 protein levels in plasma.

Social partner discrimination based on sounds and scents in Asian small-clawed otters (Aonyx cinereus).

Ability to discriminate familiar conspecifics is an essential competence in any group-living species, ensuring socio-spatial cohesion, but in many animals, such as mustelids, the relative importance of the different communicative modalities for discrimination is poorly understood. In otters, there is evidence of intra-specific variation in physical appearance and in feces chemical profile, but the potential for acoustic identity coding as well as for identity decoding in visual, acoustic and olfactive domains remains unexplored. We investigated the acoustic structure of contact calls in five captive groups of small-clawed otters and found that it is possible to reliably assign one particular call to a given adult male caller. Females discriminated between familiar and unfamiliar adult males based on their sound (playback) and smell (feces) but not based on their picture, suggesting abilities to memorize and use acoustic and olfactive signatures in their daily social life.

Recombination between genes located on nonhomologous chromosomes in Saccharomyces cerevisiae.

We constructed strains of Saccharomyces cerevisiae that contained two different mutant alleles of either the leu2 gene or the ura3 gene. These repeated genes were located on chromosomes V and XII and the two leu2- alleles were located on chromosomes III and XII. Genetic interactions between the two mutant copies of a gene were detected by the generation of either Leu+ or Ura+ revertants. Both spontaneous and ultraviolet irradiation-induced revertants were examined. By genetic and physical analysis, we have shown that Leu+ or Ura+ revertants can arise by a variety of different genetic interactions. The most common type of genetic interaction is the nonreciprocal transfer of information from one repeat to the other. We also detected reciprocal recombination between repeated genes, resulting in reciprocally translocated chromosomes.

Analysis of fluctuations in the activity of rat pineal tyrosine hydroxylase.

Tyrosine hydroxylase was measured in pineals removed from light-adapted and dark-adapted rats. The animals were adapted to the appropriate light situation for approximately 5 h before removal of the pineals. Bilateral ganglionectomy confirmed that all detectable enzyme activity in the pineal appears present in sympathetic fibers originating in the superior cervical ganglia. An analysis of tyrosine hydroxylase at subsaturating cofactor concentrations in dark-adapted rats revealed activity which was 60% higher than in appropriate light control animals. Further kinetic analysis showed that the K(m) for the synthetic cofactor, 6-methyltetrahydropterin, for dark-adapted animals was 0.8 + or - 0.1 mM which was significantly lower than a K(m) value of 1.4 + or - 0.2 mM for light adapted animals. Thus the rate of norepinephrine synthesis in vivo could increase due to an alteration in the enzyme molecule, which affects its interaction with substrate. These findings support previously documented results which show both an increased turnover and an increase in the concentration of norepinephrine in the pineals of dark-adapted rats.

Dietary oyster mushroom (Pleurotus ostreatus) accelerates plasma cholesterol turnover in hypercholesterolaemic rat.

The effect of adding 5% powdered oyster mushroom (Pleurotus ostreatus) during 12 weeks on kinetic parameters of cholesterol metabolism was studied in male rats (Wistar, initial body weight 85 g) fed a semisynthetic diet containing 0.3% of cholesterol. The plasma cholesterol decay curve (examined for the final 29 days of the experiment after a single dose of cholesterol-4-14C) was evaluated by mathematical analysis using a two-pool model of plasma cholesterol metabolism. The oyster mushroom in the diet reduced the half-times of both exponentials resulting in lower calculated values (by 28%) of total entry of cholesterol into the body cholesterol pool (absorption+endogenous synthesis) and lower sizes of both pools (with slower and faster cholesterol exchange). The rate of cholesterol exchange between the pools was enhanced and the rate of total clearance of cholesterol from the system (metabolic turnover rate of cholesterol i.e. the rate of degradation and excretion of cholesterol from the organism) was enhanced by 50%. The oyster mushroom diet effectively prevented the progress of hypercholesterolaemia (decrease by 38%) and cholesterol accumulation in liver (decrease by 25%) that were induced by the cholesterol diet.

Accuracy of electrocardiogram reading by family practice residents.

OBJECTIVES: This study evaluated the electrocardiogram (EKG) reading skills of family practice residents. METHODS: A multicenter study was carried out to evaluate the accuracy of EKG reading in the family practice setting. Based on the frequency and potential for clinical significance, we chose 18 common findings on 10 EKGs for evaluation. The EKGs were then distributed to residents at six family practice residencies. Residents were given one point for the identification of each correct EKG finding and scored based on the number correct over a total of 18. RESULTS: Sixty-one residents (20 first year, 23 second year, and 18 third year) completed readings for 10 EKGs and were evaluated for their ability to identify 18 EKG findings. The median score out of 18 possible points for all first-, second-, and third-year residents was 12, 12, and 11.5, respectively. Twenty-one percent of residents did not correctly identify a tracing of an acute myocardial infarction. Data analysis showed no statistically significant difference among the three groups of residents. CONCLUSIONS: We evaluated the accuracy of EKG reading skills of family practice residents at each year of training. This study suggests that EKG reading skills do not improve during residency, and further study of curricular change to improve these skills should be considered.

Occurrence of a high temperature sensitivity of chloroplast ribosome formation in several higher plants.

A specific high temperature-induced deficiency of chloroplast ribosome formation, as indicated by the absence of chloroplast rRNA, has been observed in the leaves of light- or dark-grown seedlings of Avena sativa L., Hordeum vulgare L., and Triticum aestivum L. at certain temperatures between 28 and 34 C. While the growth of the leaves (size, morphology, total amino nitrogen content) was little affected by the elevated temperature, chlorophyll accumulation was strongly inhibited, amounting to only 2 to 20% of its content in 22 C-grown leaves which were used as a reference for normal development. The carotenoid contents were also lower but still reached at least 15 to 20% of the corresponding measurements at 22 C. Ribulose-1,5-bisphosphate carboxylase was absent at the higher temperature while NADP-glyceralde-hydephosphate dehydrogenase reached high activities. For the peroxisomal marker enzyme hydroxypyruvate reductase, 30 to 70% of the activity present in 22 C-grown leaves was found in extracts from high temperature-grown leaves. Fumarase reached 1.5- to 4-fold higher activities at the elevated growth temperature than at 22 C. Leaves of Pisum sativum L. were completely chlorotic and deficient of 70S ribosomes at 33 C but simultaneously suffered from a severe general inhibition of their growth. In Zea mays L., a formation of chlorotic leaves was not observed at elevated temperatures.

Transient cortical blindness due to hypertensive encephalopathy. Magnetic resonance imaging correlation.

Striking reversible signal intense magnetic resonance imaging (MRI) lesions were observed in the occipital cortex of a 16-year-old girl who presented with an attack of transient cortical blindness as the initial manifestation of hypertensive encephalopathy (HTE). The lesions were seen to best advantage on T2-weighted imaging and were not visible on computed tomography (CT). It is proposed that such occipital lobe MRI lesions likely reflect extravasation of fluid and proteins across the blood brain barrier, damaged as a consequence of cerebral autoregulation failure.

31P NMR examination of phosphorus metabolites in the aqueous, acidic, and organic extracts of Phaseolus vulgaris seeds.

31P NMR spectroscopy was used to compare the phosphorus compound content in aqueous, acidic, and organic extracts of Phaseolus vulgaris seeds. Two chloroform-methanol and three ethanol extractions were used to isolate phospholipids from dry cotyledons and the phospholipid profiles were compared. Variations in phospholipid composition and artificially high concentrations of lysophosphatidylcholine were observed in the ethanol extracts. Other phosphorus compounds were extracted using perchloric acid, trichloroacetic acid, trichloroacetic acid in ether, hydrochloric acid, boiling water, and aqueous Hepes. The Hepes extraction was introduced in order to compare the results of a gentle procedure with those involving heat and acid treatments. Low concentrations of phospho-sugars and other phosphorus metabolites were found in all these extracts. High concentrations of phytate were found in all aqueous and acidic extractions; however, 31P NMR spectra of aqueous extractions did not show the phytate resonance. The NMR silence of the phytate resonances is attributed to complexation of phytate. The 31P NMR spectra of aqueous extracts contained a broad resonance at 0.1 ppm assigned to protein-bound RNA. Various extraction procedures on the same biological material are presented, and the comparison of these methods will facilitate future analysis and interpretation of literature reports involving these methods of tissue analysis.

Biosynthesis of the linkage region of the mycobacterial cell wall.

The "core" structure of the cell wall of Mycobacterium and related genera is unique among prokaryotes, consisting of a covalently linked complex of mycolic acids, D-arabinan and D-galactan (mycolylarabinogalactan, mAG), which, in turn, is linked to peptidoglycan via a special linkage unit, -alpha-L-Rhap(1-->3)-D-GlcNAc-P-. Little is known of the biosynthesis of this complex, although it is the site of action of several common anti-tuberculosis drugs. Isolated cell membranes of Mycobacterium smegmatis catalyzed the incorporation of [14C]GlcNAc from UDP-[14C]GlcNAc into two glycolipids (1 and 2) and of [14C]Rha from TDP-[14C]Rha into glycolipid 2. These products were characterized as polyprenol-P-P-GlcNAc (glycolipid 1) and polyprenol-P-P-GlcNAc-Rha (glycolipid 2) based on sensitivity of synthesis to tunicamycin, chromatographic characterization of the products of mild acid hydrolysis, and mass spectral analysis of the glycosyl and polyprenyl units. Glycolipids 1 and 2 were shown to be precursors of the linkage unit in polymerized cell wall. The inclusion in the assays of UDP-[14C]Galp and a preparation of cell walls allowed the incorporation of [14C]Gal into two further glycolipids (3 and 4). Preliminary evidence indicates a precursor-product relationship among glycolipids 1, 2, 3, and 4. Thus, the first steps in the biosynthesis of the mycobacterial cell wall involve synthesis of the linkage disaccharide on a polyprenyl-P-P carrier followed by growth of the galactan unit. Assays are thus defined for the screening of new anti-tuberculosis drugs active against cell wall synthesis.

Transformation and rescue of a flightless Drosophila tropomyosin mutant.

In the Drosophila flightless mutant Ifm(3)3, a transposable element inserted into the alternatively spliced fourth exon of the tropomyosin I (TmI) gene prevents proper expression of Ifm-TmI, the tropomyosin isoform found in indirect flight muscle. We have rescued the flightless phenotype of Ifm(3)3 flies using P-element-mediated transformation with a segment of the Drosophila genome containing the wild-type TmI gene plus 2.5 kb of 5' flanking and 2 kb of 3' flanking DNA. The inserted TmI gene is expressed with the proper developmental and tissue specificity, although its level of expression varies among the five transformed lines examined. These conclusions are based on analyses of flight, myofibrillar morphology, and TmI RNA and protein levels. A minimum of two copies of the inserted TmI gene per cell is necessary to restore flight to most of the flies in each line. We also show that the Ifm-TmI isoform is expressed in the leg muscle of wild-type flies and is decreased in Ifm(3)3 leg muscle. Homozygous Ifm(3)3 mutants do not jump. The ability to jump can be restored with a single copy of the wild-type TmI gene per cell.