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921.
Fast-growing broiler chickens not uncommonly exhibit elevated pulmonary vascular resistance that leads to pulmonary hypertension and right ventricular failure. We tested the hypothesis that a distended gastrointestinal tract in these full-fed birds results in an abnormally low tidal volume and minute ventilation that could lead to pulmonary hypoxia, pulmonary arterial vasoconstriction, right ventricular failure, and ascites. Tidal volume, respiratory frequency, heart rate, percentage saturation of hemoglobin with oxygen (HbO2), O2 consumption, and carbon dioxide elimination were measured on fast-growing broiler chickens when full-fed and after 3, 6, and 9 h of feed deprivation. Tidal volume of full-fed birds was not abnormally low despite HbO2 values varying from above 80% to nearly 60%. Importantly, HbO2 was found to be markedly increased in the hypoxemic birds at and beyond a 3-h period without feed, despite a reduction in minute ventilation. This response was not caused by a decrease in O2 consumption. Thus, limitation of gas intake at the mouth was not the cause of the hypoxemia. The data suggest that feed deprivation results in an increase in parabronchial ventilation, possibly from improvement in aerodynamic valving, which would reduce pulmonary hypoxic vasoconstriction and right ventricular failure. 相似文献
922.
In order to determine whether simple luminance profiles are located by their peaks or centroids we performed a three element alignment task where the central element's degree of luminance asymmetry was randomly chosen from a flat distribution (skew noise). The central element with its randomly chosen skew was either positioned using the peak or centroid of its distribution. Accuracy is invariant with the magnitude of the skew noise for the centroid but not the peak condition. We conclude that the human visual system assigns position tags using centroids not peaks of luminance distributions for gabors. However this is not the case for Gaussian blobs, where a measure closer to the midpoint is used for our stimulus arrangement. 相似文献
923.
A 42-year-old man sustained a gunshot wound to the frontal process of the left maxilla just lateral to the nasal bone medial to the maxilla that caused profuse hemorrhage. Anterior and posterior nasal packing along with packing of the gunshot wound with Vaseline gauze did not control the hemorrhage. A 28 French (30-cc balloon) Foley catheter was placed directly into the wound, and bleeding stopped immediately upon inflation of the balloon with 30 cc of sterile water. Arteriography identified bleeding from an anterior branch of the maxillary artery that was successfully embolized. 相似文献
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MC Rizzo CK Naspitz E Fernández-Caldas RF Lockey I Mimi?a D Solé 《Canadian Metallurgical Quarterly》1997,8(3):121-126
Osteoporosis is not an inevitable accompaniment of aging. Rather, it evolves silently over a lifetime, with its attendant morbidities occurring late in life. It is no longer the standard of care to wait until the primary morbidity strikes to begin therapy. A better outcome is always achieved when the individuals at risk are identified early, lessening or even preventing morbidity such as osteoporotic fractures. Recent surveys show a reluctance on the part of many physicians to diagnose or treat osteoporosis in their patients. A second level of resistance is often seen even after fractures occur. Either scenario is particularly unfortunate as therapies currently exist that can significantly reduce future morbidity and probably mortality. Physicians must recognize that patients who have had one fracture are at significantly greater risk to sustain more fractures and are more likely to suffer chronic debilitating musculoskeletal failure. Therefore, in the elderly fracturing patient, even more intensive intervention (fracture prevention) is required. 相似文献
926.
OBJECTIVE: Reports on the aetiology and risk of occupational rhinitis in different occupations are scarce. METHOD: The purpose of this study was to find the occupations with an increased risk of occupational rhinitis. Age and gender differences in occupational rhinitis and occupational asthma were also compared, and the most common causes of occupational rhinitis were analysed. DESIGN: This study covered the cases of occupational rhinitis and asthma reported to the Finnish Register of Occupational Diseases during the years 1986-1991. The cases on the Register were linked to the longitudinal census data file from the Finnish censuses. RESULTS: During 1986-1991, 1244 new cases of occupational rhinitis (474 women and 497 men) and 1867 new cases of occupational asthma (916 women and 951 men) were reported to the Register. Animal dander, flours, wood dusts, textiles, phthalic acid anhydrides and storage mites were important causes of occupational rhinitis. The highest relative risk of occupational rhinitis was among furriers, the age-standardized rate ratio (SRR) was 30.0. Bakers and livestock breeders had also a markedly elevated relative risk (SRR = 22.0). Men had the highest incidence of occupational rhinitis at the age of 25-29 years and among women the incidence gradually increased and reached the peak in the group 40-44 years of age. CONCLUSION: Furriers, bakers, and livestock breeders had the most elevated relative risk of occupational rhinitis. Occupational rhinitis cases reported at a younger age than asthma, suggesting that rhinitis often precedes asthma. 相似文献
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MJ Dunne C Kane RM Shepherd JA Sanchez RF James PR Johnson A Aynsley-Green S Lu JP Clement KJ Lindley S Seino L Aguilar-Bryan 《Canadian Metallurgical Quarterly》1997,336(10):703-706
BACKGROUND: Corneal HLA-DR antigens are going to be lost during organ culture storage. This study investigated if this phenomenon is based on down-regulation of the HLA-DR antigen, or on a loss of the HLA-DR-positive corneal Langerhans cells (LCs). MATERIAL AND METHODS: Corneal LCs were stained in situ by the method of fluorescence-associated immunohistochemistry, and the organ culture mediums underwent flow cytometric analysis for HLA-DR-positive corneal LC at the end of the storage period. RESULTS: All stored corneas were negative for HLA-DR after 14 days and HLA-DR antigens could be detected in culture medium at the end of the storage time. CONCLUSION: Flow cytometry showed that organ culture storage leads to loss of HLA-DR-positive cells and not only to a loss of antigen presentation. 相似文献