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61.
Research on human resiliency in the face of adversity has gained widespread currency in the study of the developmental outcomes for children exposed to multiple risk factors. This article reviews several of these studies from a multilevel perspective, with a view to documenting their contributions and limitations and what needs to be done in the future. 相似文献
62.
SA Whitmore C Settasatian J Crawford KM Lower B McCallum R Seshadri CJ Cornelisse EW Moerland AM Cleton-Jansen AJ Tipping CG Mathew M Savnio A Savoia P Verlander AD Auerbach C Van Berkel JC Pronk NA Doggett DF Callen 《Canadian Metallurgical Quarterly》1998,52(3):325-331
BACKGROUND: Both fibroblast-mediated cytokine gene therapy and bone marrow transplantation (BMT) have proven to be efficient protocols for the recovery of bone marrow depression. In this report, the effects of fibroblast-mediated interleukin (IL)-6 gene therapy, in combination with BMT, on the recovery of irradiation-induced bone marrow depression were investigated. METHODS: NIH3T3 fibroblast cells engineered to secrete IL-6 (NIH3T3-IL-6) or NIH3T3 cells transduced with the neomycin gene (NIH3T3-Neo), in combination with 10(7), 10(6), or 10(5) syngeneic bone marrow cells, were implanted into irradiated mice. RESULTS: The platelets and white blood cells in the peripheral blood of the irradiated mice increased greatly 12 days after implantation of NIH3T3-IL-6 cells and BMT, the white blood cell counts were restored to a normal level 32 days after the combined therapy, and the platelet number was obviously higher than that in mice implanted with NIH3T3-Neo and BMT. Twenty and 25 days after the combined therapy, the mice showed accelerated recovery of colony-forming unit (CFU)-granulocyte/macrophages and CFU-megakaryocytes when compared with the mice implanted with NIH3T3-Neo cells and BMT. Ten days after lethal irradiation with gamma rays, the spleens formed more CFU-spleen in mice implanted with NIH3T3-IL-6 cells and BMT than in mice injected with phosphate-buffered saline or NIH3T3-Neo cells. Combined therapy with NIH3T3-IL-6 cell implantation and BMT delayed the survival period of the hematopoietic-depressed mice significantly when compared with therapy with NIH3T3-Neo cell implantation and BMT. CONCLUSIONS: These data demonstrated that the combined therapy of fibroblast-mediated IL-6 gene therapy and BMT could significantly promote the recovery of irradiation-induced hematopoietic depression. 相似文献
63.
64.
CJ Frary RB Devereux R Kramer-Fox RB Roberts HS Ruchlin 《Canadian Metallurgical Quarterly》1994,73(4):263-267
In 1990-1991, a national survey was conducted to estimate the prevalence of Salmonella species among Canadian commercial turkey flocks. Two hundred and seventy flocks were randomly selected across Canada. The proportion sampled from each province was selected according to each province's share of the national turkey market. Samples, consisting of 12 pooled litter and four pooled dust samples, were used to determine the Salmonella status of the environment of each flock. Additionally, a one kilogram sample of feed was taken from each flock premise. Salmonella was recovered from environmental samples in 234/270 (86.7%) of flocks and from feed samples in 26/266 (9.8%) of flocks. Forty-eight different Salmonella serovars were isolated from flock environmental samples. The most prevalent serovars were S. anatum, S. hadar, S. agona, S. heidelberg and S. saintpaul which were isolated from 53/270 (19.6%), 49/270 (18.1%), 49/270 (18.1%), 42/270 (15.6%) and 34/270 (12.6%) flocks, respectively. 相似文献
65.
J Jiménez-Castellanos A Carmona L Castellanos CJ Catalina-Herrera 《Canadian Metallurgical Quarterly》1995,17(2):139-43, 14-6
In the present paper we have studied the gross (mesoscopic) anatomy of the ophthalmic a. in humans, using magnification by microsurgical systems to obtain data on the origin and course of this artery and its main collateral branches. Comparison of our results with previous reports indicates that, although the anatomical variations of the vascular system are well known, some patterns of frequency may be emphasised. Thus, the ophthalmic a. was usually found as a collateral branch of the internal carotid a., although other origins were also found. The ophthalmic a., once inside the orbit, followed a course above the optic nerve in most cases. All the collateral branches of the ophthalmic a., with the exception of the muscular branches, showed great constancy. 相似文献
66.
Absorbable stapling devices have been described by several groups for the creation of continent urinary diversions. Experience with these devices in the creation of the LeBag ileocecal orthotopic pouch is described. Use of the staplers simplifies pouch construction and yields functional results similar to hand-sewn reservoirs. 相似文献
67.
We present a far-field analysis of ion diffusion toward a channel embedded in a membrane with a fixed charge density. The Smoluchowski equation, which represents the 3D problem, is approximated by a system of coupled three- and two-dimensional diffusions. The 2D diffusion models the quasi-two-dimensional diffusion of ions in a boundary layer in which the electrical potential interaction with the membrane surface charge is important. The 3D diffusion models ion transport in the bulk region outside the boundary layer. Analytical expressions for concentration and flux are developed that are accurate far from the channel entrance. These provide boundary conditions for a numerical solution of the problem. Our results are used to calculate far-field ion flows corresponding to experiments of Bell and Miller (Biophys. J. 45:279, 1984). 相似文献
68.
Lactation records (n = 2362) of 1402 crossbred cows in 22 cooperating dairy herds in southeastern Brazil were evaluated. Cows were mixtures of Zebu (Gir, Guzera, and unknown) and European breeding (mostly Holstein). Lactation milk yields were expressed as total, 3050-d, or deviated 305-d yields, either adjusted or unadjusted for days in milk (DIM). Mean DIM was 280. Arithmetic means unadjusted for DIM were 1942, 1666, and 5 kg per record. Milk yields of daughters from sires of 6/8 and 7/8 European breeds were higher than yields of daughters from sires of 5/8 European breeds when data were either adjusted or unadjusted for DIM. The differences associated with breed group of sire were only slightly reduced when records were adjusted for DIM. There was no evidence of a decline in milk yield as the fraction of European breeding of the sire increased from 6/8 to 7/8. For a given breed group of sire, whether the grandsire was purebred or crossbred had no detectable effect. These results should be useful in determining strategies for crossbreeding of dairy cows in tropical areas, particularly when crossbred sires are used. 相似文献
69.
70.
N Reinisch S Kiechl C Mayr P Schratzberger S Dunzendorfer CM K?hler T Buratti J Willeit CJ Wiedermann 《Canadian Metallurgical Quarterly》1998,28(10):787-792
BACKGROUND: In atherosclerosis, both reductions and elevations in plasma levels of antioxidants have been reported. This study investigated total antioxidant capacity of plasma from subjects with atherosclerotic disease. MATERIALS AND METHODS: The study population consisted of 48 men with or without carotid atherosclerosis. At baseline (1990) carotid arteries were evaluated by duplex sonography and plasma samples were obtained for testing antioxidant capacity by two different test systems. One assay system used neutrophils from healthy volunteers as a source of oxygen free radicals activating the non-fluorescent dichlorofluorescin diacetate in the presence of antioxidant containing plasma from study subjects. In the other test system, total plasma antioxidants were detected colorimetrically by using 2,2'-azino-di-(3-ethylbenzthiazoline sulphonate), metmyoglobin and superoxide in the presence of plasma. Carotid arteries were re-evaluated for the development of new plaques 5 years later (1995). RESULTS: Increased baseline total antioxidant capacity of plasma was significantly associated with the development of new atherosclerotic lesions during a period of 5 years. CONCLUSIONS: Endogenous antioxidant capacity of plasma is increased in patients with active atherosclerotic disease. As scavenging of oxygen free radicals is thought to protect from atherogenesis, elevated antioxidative capacity may represent an adaptive mechanism. 相似文献