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排序方式: 共有1103条查询结果,搜索用时 15 毫秒
991.
CG Margolis 《Canadian Metallurgical Quarterly》1997,24(4):809-823
SCFE is the most common hip abnormality in adolescence. The subsequent development and severity of degenerative changes is related to the degree of slippage and to delay in diagnosis. Awareness of this diagnostic possibility in the population at greatest risk and knowledge of subtle and early radiographic findings will allow prompt diagnosis and treatment of SCFE. Follow-up radiographic examination should be used to evaluate for physeal fusion and any complications, including progression of the slip, hardware complications, chondrolysis, avascular necrosis, and secondary osteoarthritis. 相似文献
992.
CG Thornton KM MacLellan TL Brink DE Lockwood M Romagnoli J Turner WG Merz RS Schwalbe M Moody Y Lue S Passen 《Canadian Metallurgical Quarterly》1998,36(7):1996-2003
A novel method for processing respiratory specimens to improve culture and acid-fast staining of mycobacteria is introduced. This new method utilized N,N-dimethyl-N-(n-octadecyl)-N-(3-carboxypropyl)ammonium inner salt (Chemical Abstract Service no. 78195-27-4), also known as C18-carboxypropylbetaine (CB-18). In a blinded, five-center study, CB-18-based processing was compared to the standard method combining NALC and NaOH (NALC/NaOH). A total of 573 respiratory specimens were tested. Individual specimens were split approximately equally; the host institutions processed half of each specimen by the NALC/NaOH method, while the other half was processed with CB-18 at Quest Diagnostics--Baltimore. A total of 106 specimens were culture positive for acid-fast bacilli (AFB). Replacement of the primary decontamination agent with CB-18 caused changes in all diagnostic parameters. Aggregate culture sensitivity improved by approximately 43% (P < 0.01), and smear sensitivity improved by approximately 58% (P < 0.01). The sensitivity of smear relative to that of M. tuberculosis isolates exceeded 93% (P < 0.01) when specimens were processed with CB-18. The average times to a positive result were reduced by 7.3 days in liquid culture (P < 0.01) and 5.3 days on solid media (P < 0.05); however, the CB-18 method had a 20.8% contamination rate in liquid culture versus a rate of approximately 7.5% with NALC/NaOH processing. There were also unusual reductions in liquid culture sensitivity and smear specificity among CB-18-processed specimens. The characteristics of the latter parameters suggested that refinement of the CB-18 processing method should allow further improvements in culture sensitivity. This study showed that the CB-18 method has the potential to improve both smear and culture detection for these important human pathogens. 相似文献
993.
ES Kikkinides GC Charalambopoulou AK Stubos NK Kanellopoulos CG Varelas CA Steiner 《Canadian Metallurgical Quarterly》1998,51(2-3):313-325
A comprehensive two phase model is developed to describe the sustained release of a solute or drug from a biphasic hydrogel substrate. Such a material consists of a continuous hydrophilic phase (polymer backbone in water) and a dispersion of spherical microdomains made of the hydrophobic side chains of the polymer organised in a micelle like fashion. The solute or drug is assumed to be encapsulated within the dispersed microdomains, and to diffuse from the interior to the surface of the microdomain where it exchanges following a Langmuir isotherm. Mass transfer to the bulk phase occurs by desorption of the drug from the surface through a driving force that is proportional to the difference of surface and bulk concentration. Accordingly the drug is released to the surroundings by diffusion through the bulk. Depending on the values of the Langmuir constant and assuming well stirred behaviour in the interior of the microdomain, the present model results in either of the two asymptotic models developed in previous studies. The results of a parametric study show that the desired steady state flux of a specific drug to the surroundings may be obtained given appropriate values of structural properties of the material. This conclusion is further supported when using this model to simulate earlier experimental results. The polymer structural properties can be manipulated easily during the fabrication of dispersed-phase networks, as indicated by preliminary experiments. 相似文献
994.
AC Aisenberg DM Finkelstein KP Doppke FC Koerner JF Boivin CG Willett 《Canadian Metallurgical Quarterly》1997,79(6):1203-1210
BACKGROUND: Treatment-associated second neoplasms have emerged as a major threat to the continued survival of patients cured of Hodgkin's disease. In this study, the authors investigated the risk of breast carcinoma in an irradiated Hodgkin's disease population. METHODS: One hundred and eleven women younger than 60 years presenting between 1964 and 1984 with Stage I and II Hodgkin's disease who received mantle irradiation were retrospectively analyzed and compared with an age specific population. Median follow-up was 18 years (range, 10-30 years), and the median age at initiation of therapy was 24 years. Kaplan-Meier actuarial risks, relative risks (RRs) (the ratio of the observed to the expected cases) with 95% confidence intervals (CIs), and the log rank test for trends were calculated. RESULTS: Fourteen women developed breast carcinoma: 8 of 33 patients younger than 20 years at the time of irradiation, 5 of 48 patients age 20 to 29 years, and 1 of 30 patients age 30 years or older. Actuarial calculation predicted a 34.0% (CI, 14.2-53.8) risk of breast carcinoma at 25 years after therapy for the youngest group, 22.3% (CI, 4.1-40.5) for the group of intermediate age, and 3.5% (CI, 0-10.1) for the oldest group. The RR of breast carcinoma was 56 (CI, 23.3-107) for those 19 years or younger at the time of treatment, 7.0 (CI, 2.3-16.4) for those age 20-29 years, and 0.9 (CI, 0-5.3) for those 30 years and older. Excluding 1 patient who was age 38 years at the time of irradiation, the remaining 13 breast carcinomas were tightly clustered in women irradiated between the ages of 14 through 25, and were detected in years 11 through 25 after treatment, with 7 occurring in years 15 through 18. CONCLUSIONS: Women younger than 30 years, particularly those younger than 20 years, who have received mantle irradiation for Hodgkin's disease require meticulous follow-up for breast carcinoma. The high incidence of breast carcinoma in this patient population should be considered when making treatment decisions in young women with early stage Hodgkin's disease. 相似文献
995.
TM Zizic KC Hoffman PA Holt DS Hungerford JR O'Dell MA Jacobs CG Lewis CL Deal JR Caldwell JG Cholewczynski 《Canadian Metallurgical Quarterly》1995,22(9):1757-1761
OBJECTIVE: The safety and effectiveness of pulsed electrical stimulation was evaluated for the treatment of osteoarthritis (OA) of the knee. METHODS: A multicenter, double blind, randomized, placebo controlled trial that enrolled 78 patients with OA of the knee incorporated 3 primary efficacy variables of patients' pain, patients' function, and physician global evaluation of patients' condition, and 6 secondary variables that included duration of morning stiffness, range of motion, knee tenderness, joint swelling, joint circumference, and walking time. Measurements were recorded at baseline and during the 4 week treatment period. RESULTS: Patients treated with the active devices showed significantly greater improvement than the placebo group for all primary efficacy variables in comparisons of mean change from baseline to the end of treatment (p < 0.05). Improvement of > or = 50% from baseline was demonstrated in at least one primary efficacy variable in 50% of the active device group, in 2 variables in 32%, and in all 3 variables in 24%. In the placebo group improvement of > or = 50% occurred in 36% for one, 6% for 2, and 6% for 3 variables. Mean morning stiffness decreased 20 min in the active device group and increased 2 min in the placebo group (p < 0.05). No statistically significant differences were observed for tenderness, swelling, or walking time. CONCLUSION: The improvements in clinical measures for pain and function found in this study suggest that pulsed electrical stimulation is effective for treating OA of the knee. Studies for longterm effects are warranted. 相似文献
996.
997.
C Foged C Halldin C Loc'h B Mazière S Pauli M Maziére HC Hansen T Suhara CG Swahn P Karlsson L Farde 《Canadian Metallurgical Quarterly》1997,24(10):1261-1267
NNC 13-8241 has recently been labelled with iodine-123 and developed as a metabolically stable benzodiazepine receptor ligand for single-photon emission computed tomography (SPECT) in monkeys and man. NNC 13-8199 is a bromo-analogue of NNC 13-8241. This partial agonist binds selectively and with subnanomolar affinity to the benzodiazepine receptors. We prepared 76Br labelled NNC 13-8199 from the trimethyltin precursor by the chloramine-T method. Carbon-11 labelled NNC 13-8199 was synthesised by N-alkylation of the nitrogen of the amide group with [11C]methyl iodide. Positron emission tomography (PET) examination with the two radioligands in monkeys demonstrated a high uptake of radioactivity in the occipital, temporal and frontal cortex. In the study with [76Br]NNC 13-8199, the monkey brain uptake continued to increase until the time of displacement with flumazenil at 215 min after injection. For both radioligands the radioactivity in the cortical brain regions was markedly reduced after displacement with flumazenil. More than 98% of the radioactivity in monkey plasma represented unchanged radioligand 40 min after injection. The low degree of metabolism indicates that NNC 13-8199 is metabolically much more stable than hitherto developed PET radioligands for imaging of benzodiazepine receptors in the primate brain. [76Br]NNC 13-8199 has potential as a radioligand in human PET studies using models where a slow metabolism is an advantage. 相似文献
998.
CG Kevil N Okayama SD Trocha TJ Kalogeris LL Coe RD Specian CP Davis JS Alexander 《Canadian Metallurgical Quarterly》1998,5(2-3):197-210
ColE1-derived plasmids containing different recombinant genes which are controlled by the tac promoter were amplified following induction with IPTG, but no amplification occurred if product formation was not induced. The plasmid copy number of recombinant E. coli increased three- to sixfold within a period of about 6 h in shake flask experiments, batch cultures, and glucose-limited fed-batch cultivations. Plasmid amplification occurred in E. coli B strains as well as in K-12 strains with different plasmids (rop+ and rop-) coding for various heterologous proteins. The amplification was not caused by a toxic effect of IPTG, but was related to a strong inhibition of translation and chromosomal replication after the induction of heterologous gene expression. Similar to the amplification after chloramphenicol addition, plasmid replication proceeded even if oriC replication and translation were inhibited following strong induction of a recombinant gene. In accordance with the effect of chloramphenicol, the level of ppGpp, which is a negative regulator of ColE1 derived plasmid replication, decreased after induction. 相似文献
999.
JE Rasko D Metcalf B Alexander A Strasser CG Begley 《Canadian Metallurgical Quarterly》1997,11(5):732-742
In this study neonatal mice expressing a GM-CSF transgene (GMT mice), and their normal littermate controls, were infected with Moloney murine leukemia virus (MoMLV) to examine in vivo tumorigenesis. By 200 days, all of the GMT mice had died whereas median survival had not been reached in the littermates (P < 0.0003). Thymomas developed in 32% of GMT mice and were more frequently CD4+CD8+ (83%) compared to the CD4+CD8- phenotype seen in 90% of thymomas developing in MoMLV-infected littermate mice. A primitive myeloid leukemia was induced in 21% of GMT mice, but none of the littermates. To characterize further the nature of the leukemic cells, a factor-dependent cell line (DGM36) was derived. DGM36 cells were tumorigenic, capable of differentiation to neutrophils, macrophages and eosinophils, and contained a partial deletion of chromosome 2. A subline arose spontaneously that was factor-independent and produced GM-CSF in an autocrine manner (IGM36 cells). Stimulation of the IGM36 cells with TNF alpha and IFNgamma resulted in increased expression of B7-1, class I MHC and class II MHC and consequent presentation of antigen in allogeneic MLRs. IGM36 cells thereby satisfy many of the criteria of dendritic cells and consequently may be used to examine antigen presentation by leukemic cells. This is the first report of primary myeloid leukemias arising in GMT mice and documents the derivation of a multipotential, autocrine leukemic cell line with dendritic cell characteristics. 相似文献
1000.