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We synthesized a novel ligand [4,5-3H-Leu9]-Neurokinin A (3H-NKA, S.A 117-144 Ci/mmol), and evaluated its binding to hamster urinary bladder membranes (HUBM). The ligand bound to HUBM in a highly-specific (94 +/- 4%) and protein-dependent manner. Binding was rapid (k1 = 0.037 nM-1*min-1) and saturable (Bmax = 1210 +/- 177 fmol/mg protein), to a single population of high-affinity sites (KD = 2.41 +/- 0.15 nM, nH = 0.99 +/- 0.02). Binding was inhibited by non-hydrolyzable GTP analogs. Competition experiments with HUBM demonstrated the following rank order of potency: NKA > Kassinin > [beta-Ala8]-NKA(4-10) > [Nle10]-NKA(4-10) = Eledoisin = NKB > Physaelamin > Substance P. The selective NK-1 and NK-3 ligands, [Sar9-Met (O2)11]-SP, (+/-) CP96,345 and Senktide respectively, did not inhibit binding at 10 microM, whereas, the selective NK-2 antagonists: (+/-) SR-48,968 > L-659,877 > R396 > MEN-10,207 > MEN-10,376, inhibited binding in a competitive manner. In contrast, the low specific binding (< 30%) detected in guinea pig lung membranes, was not inhibited by selective NK-2 ligands. Over 30 ligands (0.1-10 microM) from other receptor classes, were not inhibitory. The data suggest that this new ligand binds with high-affinity and selectivity to homogeneous population of NK-2 receptors on HUBM but not on lung membranes, and is a suitable ligand to study NK-2 receptors. 相似文献
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In this observational study, we sought to assess the usefulness of pH values from residuals in intensive care unit (ICU) patients with small-bore feeding tubes. A review of the literature demonstrated that most critically ill patients were excluded in previous studies on gastric pH testing, suggesting that pH testing in critical care is not warranted. Our results demonstrated that 21% of intestinal testing and 64% of gastric testing yielded potential misinformation to the bedside nurse with regards to possible tube location. In conclusion, pH testing for small-bore tube placement and maintenance was not deemed meaningful in our critical care unit. 相似文献
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Wijkstrom-Frei C El-Chemaly S Ali-Rachedi R Gerson C Cobas MA Forteza R Salathe M Conner GE 《American journal of respiratory cell and molecular biology》2003,29(2):206-212
The lactoperoxidase (LPO) antibiotic system is a well-characterized component of mammary and salivary gland secretions. Because LPO has been shown to function in ovine airways, human airway tissue and secretions were examined for the presence of LPO and its substrate, the anion thiocyanate (SCN-). In addition, human airway secretions were tested for LPO-mediated antibacterial activity, and LPO's activity was assessed against some human airway pathogens. The data showed that normal human airway secretions contained LPO enzyme activity (0.65 +/- 0.09 microg/mg secreted protein; n = 17), and Western blots of secretions demonstrated bands of the expected sizes for LPO. LPO mRNA was detected in trachea by sequencing PCR-amplified cDNA. SCN-, LPO's substrate, was present in undiluted airway secretions at concentrations sufficient for LPO catalysis (0.46 +/- 0.19 mM; n = 8), and diluted secretions contained antibacterial activity with LPO-like properties. Immunocytochemistry localized LPO to submucosal glands in human bronchi. Finally, as expected based on the known antibacterial spectrum of the LPO system, airway secretions showed LPO-dependent activity against Pseudomonas aeruginosa. In addition, the airway LPO system was shown to be effective against Burkholderia cepacia and Haemophilus influenzae. Thus, a functional LPO system exists in human airways and may contribute to airway host defense against infection. 相似文献
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Androgen receptor YAC transgenic mice carrying CAG 45 alleles show trinucleotide repeat instability 总被引:1,自引:15,他引:1
La Spada AR; Peterson KR; Meadows SA; McClain ME; Jeng G; Chmelar RS; Haugen HA; Chen K; Singer MJ; Moore D; Trask BJ; Fischbeck KH; Clegg CH; McKnight GS 《Human molecular genetics》1998,7(6):959-967
X-linked spinal and bulbar muscular atrophy (SBMA) is caused by a CAG
repeat expansion in the first exon of the androgen receptor (AR) gene.
Disease-associated alleles (37-66 CAGs) change in length when transmitted
from parents to offspring, with a significantly greater tendency to shift
size when inherited paternally. As transgenic mice carrying human AR cDNAs
with 45 and 66 CAG repeats do not display repeat instability, we attempted
to model trinucleotide repeat instability by generating transgenic mice
with yeast artificial chromosomes (YACs) carrying AR CAG repeat expansions
in their genomic context. Studies of independent lines of AR YAC transgenic
mice with CAG 45 alleles reveal intergenerational instability at an overall
rate of approximately 10%. We also find that the 45 CAG repeat tracts are
significantly more unstable with maternal transmission and as the
transmitting mother ages. Of all the CAG/CTG repeat transgenic mice
produced to date the AR YAC CAG 45 mice are unstable with the smallest
trinucleotide repeat mutations, suggesting that the length threshold for
repeat instability in the mouse may be lowered by including the appropriate
flanking human DNA sequences. By sequence-tagged site content analysis and
long range mapping we determined that one unstable transgenic line has
integrated an approximately 70 kb segment of the AR locus due to
fragmentation of the AR YAC. Identification of the cis - acting elements
that permit CAG tract instability and the trans -acting factors that
modulate repeat instability in the AR YAC CAG 45 mice may provide insights
into the molecular basis of trinucleotide repeat instability in humans.
相似文献
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Development of a questionnaire to measure patients'' satisfaction with general practitioners'' services. 总被引:5,自引:1,他引:5 下载免费PDF全文
BACKGROUND. It is now a requirement that patients' satisfaction with the services obtained from their general practitioner should be surveyed. AIM. The aim of the study was to produce a reliable and valid multidimensional patient satisfaction questionnaire that could be used in general practice. METHOD. Items were originally derived from patients' responses to open-ended questions. The resulting 148-item Likert-scale questionnaire was completed by 1193 patients. General satisfaction items were removed from the set, and responses to remaining items underwent factor analysis. Subscales were produced from items representing each factor. Reliability and validity of each subscale were examined. RESULTS. Five subscales with a total of 40 items resulted from the factor analysis: doctors, access, nurses, appointments and facilities. Each subscale was internally reliable (Cronbach's alpha coefficient between 0.73 and 0.95), and initial tests of validity suggested that all subscales were valid. CONCLUSION. The study has resulted in a 40-item scale that has been found to be reliable and valid after initial tests. Further work to test the reliability and validity of the final version of the patient satisfaction questionnaire is described. 相似文献