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71.
DS Liss DA Waller BD Kennard D McIntire P Capra J Stephens 《Canadian Metallurgical Quarterly》1998,37(5):536-544
BACKGROUND: In the adult respiratory distress syndrome, nitric oxide (NO) inhalation improves oxygenation through reducing ventilation-perfusion mismatching, but detailed information on the pulmonary effects of NO inhalation in septic shock is scarce. The present study investigated the effects of inhaled NO on alveolar dead space (Vdalv) and venous admixture as well as on respiratory system compliance (Crs) and respiratory system resistance (Rrs) in a porcine model of septic shock. Protective effects of NO are discussed. METHODS: Thirteen anaesthetised and ventilated pigs were given an infusion of endotoxin for an observation time of 220 min to induce acute lung injury (ALI). In the NO-early group (n=6), an inhalation of 60 ppm NO was started simultaneously with the endotoxin infusion and continued for 190 min. In 7 control/NO-late animals, 60 ppm NO was administered for 30 min following 190 min of endotoxin infusion. Haemodynamics, single-breath CO2-, pressure-, and flow signals were recorded. RESULTS: Endotoxin induced haemoconcentration, pulmonary vasoconstriction, and a decrease in Crs, while venous admixture, Vdalv, and Rrs increased. In the NO-early group, the pulmonary vasoconstriction was attenuated, no increase in pulmonary venous admixture or in Vdalv was seen before cessation of NO, and the improvements in oxygenation outlasted the NO inhalation. In the control/NO-late group, the NO inhalation reversed the changes in dead space and venous admixture. NO had no effect on the changes in respiratory mechanics. CONCLUSION: In porcine ALI, 60 ppm NO diminishes pulmonary vasoconstriction and improves gas exchange by reducing pulmonary venous admixture and alveolar dead space, but does not prevent a fall in Crs. NO inhalation may help prevent long-lasting pulmonary failure. 相似文献
72.
S Yagodin RC Hardie SJ Lansdell NS Millar WT Mason DB Sattelle 《Canadian Metallurgical Quarterly》1998,23(4):219-228
The Drosophila melanogaster genes, transient receptor potential (trp) and transient receptor potential-like (trpl) encode putative plasma membrane cation channels TRP and TRPL, respectively. We have stably co-expressed Drosophila TRPL with a Drosophila muscarinic acetylcholine receptor (DM1) in a Drosophila cell line (S2 cells). Basal Ca2+ levels measured using Fura-2/AM in unstimulated S2-DM1-TRPL cells were low and indistinguishable from untransfected cells, indicating that the TRPL channels were not constitutively active in this expression system. Activation of DM1 receptor in S2-DM1-TRPL cells by 100 microM carbamylcholine induced Ca2+ release from an intracellular Ca2+ pool followed by a Gd(3+)-insensitive Ca2+ influx. Pretreatment of S2-DM1-TRPL cells with 10 microM atropine abolished Gd(3+)-insensitive Ca2+ influx triggered by carbamylcholine, but the response was not blocked by prior incubation with pertussis toxin. TRPL channels could also be reliably activated by bath application of 1 microM thapsigargin for 10 min or 100 nM thapsigargin for 60 min in Ca(2+)-free solution. In some cells, TRPL channels activated by thapsigargin could further be activated by carbamylcholine. The findings suggest that, when stably expressed in the S2 cell line, TRPL may be regulated by two distinct mechanisms: (i) store depletion; and (ii) stimulation of DM1 receptor via pertussis-toxin insensitive G-protein (or the subsequent activation of PLC), but without further requirement for Ca2+ release. 相似文献
73.
SH Ahn DW Seo YK Ko DS Sung GU Bae JW Yoon SY Hong JW Han HW Lee 《Canadian Metallurgical Quarterly》1998,21(6):657-663
OBJECTIVE: To identify factors associated with the initiation of breast-feeding in a predominantly Puerto Rican population living in inner-city Hartford, Conn. DESIGN: Retrospective study of 144 Latino women (mean +/- standard deviation age = 26.3 +/- 5.7 years) with children at least 1 year old but younger than 6 years old (mean +/- standard deviation age = 3.0 +/- 1.2 years) at the time of the survey. Women were recruited from agencies sponsoring health programs for mothers and children. They were interviewed in their homes (69%) or at the Hispanic Health Council, Hartford, Conn (31%). SUBJECTS/SETTING: Low-income Latino women who had at least 1 preschooler at the time of the interview. The women lived in inner-city Hartford, and the overwhelming majority were Puerto Rican and received welfare assistance and food stamps. Seventy-eight percent of the women chose to be interviewed in Spanish; the other 22% were interviewed in English. STATISTICAL ANALYSES: Explanatory variables that related to breast-feeding initiation (P < or = .2) in bivariate chi 2 analyses were entered into a multivariate logistic regression model that was reduced using backward stepwise elimination procedures. RESULTS: Multivariate analyses indicated that breast-feeding the previous child, shorter length of maternal residence in the United States, not receiving prenatal bottle-feeding advice, more recent birth, and higher birth weight were positively associated with breast-feeding initiation. A major reason for choosing not to breast-feed was that women felt socially uncomfortable doing it. APPLICATIONS: Breast-feeding initiation was more likely in Latino women who received prenatal breast-feeding counselling and postpartum support. Mothers of low-birth-weight infants and women breast-feeding for the first time may need additional help. These findings can be used by programs like the Special Supplemental Nutrition Program for Women, Infants, and Children to increase breast-feeding initiation. 相似文献
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77.
Hanks LM Millar JG Moreira JA Barbour JD Lacey ES McElfresh JS Reuter FR Ray AM 《Journal of chemical ecology》2007,33(5):889-907
Males of several species of longhorned beetles in the subfamily Cerambycinae produce sex or aggregation pheromones consisting
of 2,3-hexanediols and/or hydroxyhexanones. We tested the hypothesis that this diol/hydroxyketone pheromone motif is highly
conserved within the subfamily, and the resulting prediction that multiple cerambycine species will be attracted to compounds
of this type. We also tested the concept that live traps baited with generic blends of these compounds could be used as a
source of live insects from which pheromones could be collected and identified. Traps placed in a mature oak woodland and
baited with generic blends of racemic 2-hydroxyhexan-3-one and 3-hydroxyhexan-2-one captured adults of both sexes of three
cerambycine species: Xylotrechus nauticus (Mannerheim), Phymatodes lecontei Linsley, and Phymatodes decussatus decussatus (LeConte). Odors collected from male X. nauticus contained a 9:1 ratio of two male-specific compounds, (R)- and (S)-3-hydroxyhexan-2-one. Field trials with synthetic compounds determined that traps baited with (R)-3-hydroxyhexan-2-one (94% ee), alone or in blends with other isomers, attracted similar numbers of X. nauticus of both sexes, whereas (S)-3-hydroxyhexan-2-one (94% ee) attracted significantly fewer beetles. Phymatodes lecontei and P. d. decussatus also were caught in traps baited with hydroxyhexanones, as well as a few specimens of two other cerambycine species, Neoclytus modestus modestus Fall (both sexes) and Brothylus gemmulatus LeConte (only females). Male N. m. modestus produced (R)-3-hydroxyhexan-2-one, which was not present in extracts from females. Neoclytus m. modestus of both sexes also responded to lures that included (R)-3-hydroxyhexan-2-one as one of the components. The only male-specific compound found in extracts from P. lecontei was (R)-2-methylbutan-1-ol, and adults of both sexes were attracted to racemic 2-methylbutan-1-ol in field bioassays. Surprisingly,
P. lecontei of both sexes also were attracted to (R)- and (S)-3-hydroxyhexan-2-ones, although neither compound was detected in extracts from this species. Males of all five beetle species
had gland pores on their prothoraces that were similar in structure to those that have been associated with volatile pheromone
production in other cerambycine species. The attraction of multiple cerambycine species of two tribes to (R)-3-hydroxyhexan-2-one in this study, and in earlier studies with other cerambycine species, suggests that this compound is
a widespread aggregation pheromone component in this large and diverse subfamily. Overall, the attraction of multiple species
from different cerambycine tribes to this compound at a single field site supports the hypothesis that the hydroxyketone pheromone
structural motif is highly conserved within this subfamily. 相似文献
78.
Phosphatidylethanolamine (PE) and phosphatidylglycerol (PG) were isolated from aVibrio species of bacterium, known to produce eicosapentaenoic acid (20∶5n−3) andtrans-hexadecenoic acid (16∶1n−7), and subjected to phospholipase A2 degradation to determine the positional distribution of component fatty acids. At the two growth temperatures studied (20
and 5°C), both 20∶5n−3 andtrans 16∶1 n−7 were located mainly at positionsn−2 in PE. Increases in the proportions of 20∶5n−3 andtrans 16∶1n−7 in positionsn−2 with decreasing growth temperature were balanced mainly by decreases in the level ofiso-15∶0. In PG,trans 16∶1n−7 was located predominantly in positionsn-1, although the difference between the two positions was not as great as in PE. Eicosapentaenoic acid was preferentially
located in positionsn-2 of PG, particularly at 5°C when it comprised 29.9% of the total fatty acids in this position. It is concluded thattrans 16∶1n−7/20∶5n−3 is not a major molecular species of phospholipid in this species ofVibrio and that changes in the levels of molecular species of PE containingiso-15∶0 may feature in thermal acclimation. 相似文献
79.
Henning GB Millar RW Hill NJ 《Journal of the Optical Society of America. A, Optics, image science, and vision》2000,17(7):1147-1159
Two-alternative forced-choice procedures were used to measure the detectability of bright and dark bars at various locations across luminance patterns that produced Mach bands. Detection performance was significantly affected by both dark and bright Mach bands: poor detection performance was observed at locations near, but not in, the Mach bands; relatively good detection performance at locations within the Mach bands was caused by reliable changes in the width, depth, or symmetry of the bands produced by the signal bars. The changes were apparent with signals of lower luminance than that needed for detection in the plateau regions far from the bands, but, because the cues were not sufficiently reliable to allow errorless performance, unusually shaped psychometric functions were obtained. 相似文献
80.
Slices of porcine M. longissimus dorsi were packed in overwrap packs and subjected to irradiation (0 and 5 kGy) and then stored for 7 days at 4°C. Reflectance spectra were measured on the outside surface and a freshly cut surface at 7 days post irradiation. The reflectance spectra were transformed to reflex attenuance, k/s and first and second difference spectra and subjected to discriminant analysis. Using discriminant analysis it was possible to establish a calibration equation to discriminate between the spectra of irradiated and unirradiated pork for both the outside and the inside surface. When the calibration model was used to predict the classification of new samples a 100% correct grouping was obtained for the freshly cut surface, however, for the outside surface the classification ranged from 87 to 100% correct depending on the mathematical transformation of the reflectance spectra. This shows the potential of colour measurements as a possible rapid initial screening test for the identification of irradiated pork. Evaluation of the first difference spectra to identify peak positions showed significant differences in peak positions between irradiated and unirradiated pork. The position of the peaks in the irradiated sample is discussed as lending support to the hypothesis of the carboxyhaem form as the irradiated pigment. 相似文献