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31.
Selective determination of histamine by flow injection analysis 总被引:1,自引:0,他引:1
J M Hungerford K D Walker M M Wekell J E LaRose H R Throm 《Analytical chemistry》1990,62(18):1971-1976
A flow injection analysis (FIA) method for the determination of histamine is described. Control of reaction timing allows exploitation of a transient, chemical-kinetic increase in selectivity that occurs when o-phthalaldehyde reacts with histamine. The molar fluorescence ratio (selectivity) of histamine/histidine reaches a maximum value of 800 in 32 s, precluding the need for separation of histamine from histidine, spermidine, and other potential interferences in biological samples. On-line dilution prevents matrix effects and affords a linear response up to approximately 4.45 mM histamine, or 500 mg of histamine free base/100 g. Under these conditions the detection limit (3 times peak-to-peak baseline noise) is 5.5 pg (corresponding to 0.60 mg of histamine free base/100 g of sample) and throughput is 60 injections per hour. The high sensitivity and high selectivity of the method allow the rapid determination of histamine in fish with minimal sample conditioning and will find application in the determination of endogenous histamine as well, such as in blood plasma and brain tissue. 相似文献
32.
HS Chan G DeBoer JJ Thiessen A Budning JE Kingston JM O'Brien G Koren E Giesbrecht G Haddad Z Verjee JL Hungerford V Ling BL Gallie 《Canadian Metallurgical Quarterly》1996,2(9):1499-1508
Chemotherapy without radiation has not controlled most intraocular retinoblastoma, perhaps because of the common high expression of multidrug resistance P-glycoprotein that we found in retinoblastoma. Cyclosporin blocks P-glycoprotein-induced efflux of vincristine and teniposide in vitro, and possibly modulates responses to carboplatin. To avoid eye irradiation in bilateral retinoblastoma patients with RB1 germline mutations, which incurs a high second malignancy rate, we added cyclosporin A to a vincristine-teniposide-carboplatin protocol and consolidated chemotherapy responses with focal therapy. We scored patients requiring irradiation, enucleation, or focal ablation of central vision as failures. In 21 study patients, the overall relapse-free rate at a median follow-up of 3.3 years was 76%, with a rate of 92% for newly diagnosed and 50% for previously treated, relapsed retinoblastoma. Our results for the most unfavorable tumors with vitreous seeds (86% at 3.5 years) are better than published success rates of irradiation for similar tumors, or irradiation with the same chemotherapy without cyclosporin (45% at 2. 6 years). These results also exceeded our historic success rate with similar chemotherapy without cyclosporin, focal therapy, and/or radiation in 19 equivalently poor-risk patients (relapse-free rate 37% at a median follow-up of 5.6 years, P = 0.032), 16 of whom were previously untreated (relapse-free rate also 37%, P = 0.012). A better outcome occurred with higher cyclosporin blood levels and projected tissue exposure. Cyclosporin did not enhance the usual chemotoxicity. This clinical study suggests that cyclosporin improves the long-term response of retinoblastoma to chemotherapy, possibly by more than one mechanism. 相似文献
33.
DM LaPorte MA Mont V Mohan H Pierre-Jacques LC Jones DS Hungerford 《Canadian Metallurgical Quarterly》1998,(355):254-260
Core decompression is one treatment used for symptomatic osteonecrosis of the humeral head. The purpose of this report was to examine the long term outcome of this procedure. Sixty-three shoulders in 43 patients who underwent a core decompression for humeral head osteonecrosis were followed up from 2 to 20 years (mean, 10 years). None of these patients had responded to nonoperative treatment before core decompression. Results of core decompression according to preoperative Ficat and Arlet stage revealed Stage I disease had 15 of 16 (94%) successful outcomes and Stage II had 15 of 17 (88%) successful outcomes. Stage III had 16 of 23 (70%) successful results and Stage IV had one of seven (14%) successful result. Core decompression of the shoulder is a safe procedure with few recognized complications and can be performed on an outpatient basis. The procedure has been successful for Stages I, II, and III osteonecrosis in terms of early relief of pain and increased function. 相似文献
34.
Discusses the nature, structure, limitations, and potential of self-help organizations. The effective utilization of self-help organizations requires the referring therapist's awareness of the goals, methods, and services provided by the group and evaluation of the unique needs of potential group members. The value of self-help groups may depend on appropriate referral by psychotherapists. (48 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献