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101.
BM Gburek TA Kollmorgen J Qian SM D''Souza-Gburek MM Lieber RB Jenkins 《Canadian Metallurgical Quarterly》1997,157(1):223-227
We previously reported a HPLC assay method using fluorimetric detection for the simultaneous determination of urinary N2-(3-aminopropyl)biopterin (oncopterin, a natural pteridine newly found in urine from cancer patients), biopterin and neopterin. We now have observed that an unknown substance, which may be derived from methotrexate, in urine from a patient with stomach cancer interfered with the assay of oncopterin and demonstrated that oncopterin could be completely separated from the unidentified substance by HPLC using a Nucleosil 100-5SA strong cation-exchange column. Furthermore, oncopterin was not detectable by this HPLC-fluorimetric method in urine samples from patients with stomach cancer who were not treated with methotrexate. The content of urinary oncopterin from cancer patients is supposed to be very low, with less than 1 mumol/mol creatinine. The present results indicate that the peak found with elution from the C18 column was a methotrexate-derived compound and co-eluted with the analyte oncopterin. 相似文献
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SM Brouxhon AV Prasad SA Joseph DL Felten DL Bellinger 《Canadian Metallurgical Quarterly》1998,12(2):107-122
Cells of the immune system produce a variety of neuropeptides or peptide hormones, either constitutively or upon induction, and possess specific neuropeptide receptors that display ligand-receptor interactions similar to those described in the central nervous system (CNS). These findings suggest that specific subsets of lymphoid cells can produce and respond to peptides previously thought to be principally neural mediators. Recently, corticotropin releasing factor (CRF) mRNA was detected in the rat thymus and spleen, although the cells that synthesize CRF were not identified. We examined the localization of CRF and its mRNA in the rat spleen, thymus, and mesenteric lymph nodes using immunocytochemistry (ICC) and in situ hybridization (ISH), respectively. Immunoreactive CRF was present in cells in the marginal zone and red pulp of the spleen, in connective tissue septa and the subcapsular region of the thymus, and in the medullary cords and sinuses of the mesenteric lymph nodes. Dual ICC/ISH for CRF and its mRNA, respectively, demonstrated CRF mRNA over CRF-immunoreactive cells, suggesting CRF synthesis. Double-label ICC for CRF and markers for specific immunocyte subsets suggest that CRF+ cells in the spleen and thymus are macrophages. CRF+ cells in primary and secondary lymphoid organs reside in compartments that are innervated by sympathetic nerves, and some cells appears to be contacted by noradrenergic sympathetic nerve fibers, suggesting that CRF release may be influenced by the sympathetic nervous system, as it is in the hypothalamo-pituitary-adrenal axis. The presence of CRF in organs of the immune system suggests that this neuropeptide may modulate immune functions after paracrine release. 相似文献
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SM Grunberg A Sherrod R Muellenbach M Renshaw S Zaretsky AM Levine 《Canadian Metallurgical Quarterly》1994,12(5):463-468
To quantify the role of failure to request consent as a determinant of the autopsy rate, questionnaires asking whether an autopsy had been requested and the reasons for that decision were distributed to primary physicians after each death in a consecutive series of 75 patient deaths. Autopsies were requested in only 56% of cases. Common reasons to request an autopsy included unanswered medical questions (37%), medical education (22%), research protocol participation (16%), or routine policy (14%). When autopsies were not requested, the most common reason was the belief that there were no outstanding medical questions (64%). Follow-up interviews with 14 oncologists and hematologists revealed that 8 generally request autopsies (usually to contribute to medical education or to discover unexpected findings) and 6 generally do not (usually because no unexpected findings are anticipated). Attempts to increase the current low autopsy rate should address the question of when and why physicians are willing to request this procedure. 相似文献
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R Muff K Leuth?user N Bühlmann SM Foord JA Fischer W Born 《Canadian Metallurgical Quarterly》1998,441(3):366-368
In Xenopus oocytes with an endogenous calcitonin gene-related peptide (CGRP) receptor, a receptor activity modifying protein (RAMP1) enhancing CGRP stimulated chloride currents of the cystic fibrosis transmembrane regulator was recently cloned [McLatchie, L.M. et al. (1998) Nature 393, 333-339]. Here, transient expression of RAMP1 in rabbit aortic endothelial cells (RAEC) brought about stimulation of cAMP accumulation by human (h) alphaCGRP with an EC50 of 0.41 nM. This was antagonized by a CGRP receptor antagonist alphaCGRP(8-37). Co-expression of RAMP3 together with RAMP1 reduced the maximal cAMP response to h alphaCGRP by 47% (P < 0.05). The cells also express RAMP2 encoding mRNA and an adrenomedullin (ADM) receptor coupled to stimulation of cAMP formation by hADM (EC50 0.18 nM). The latter was antagonized by an ADM receptor antagonist hADM(22-52). In conclusion, expression of a CGRP receptor in RAEC requires RAMP1. The same receptor presumably recognizes ADM making use of endogenous RAMP2. The results reveal competition between the different RAMPs in the regulation of CGRP/ADM receptor activity. 相似文献
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A transurethral resection of the prostate is a good operation to relieve bladder outflow obstruction and has a low incidence of complications. However, recent work suggests that many men with symptoms may not require an operation, and it can probably be delayed in a majority for many years. This may be particularly important in old and frail patients. Many men with outflow obstruction have irritative symptoms such as urgency, frequency and nocturia; these could be treated with anticholinergics, provided they have normal flow rates and small or absent residual urine volumes. Pharmacological treatment to relieve outflow obstruction is disappointing. There may be some benefit from alpha-adrenoreceptor antagonists, but the place for 5 alpha-reductase inhibitors is still unsure. All drugs have side effects which are unacceptable in patients who are not bothered by their urinary symptoms and can wait for active treatment. 相似文献