2261. Administration of an antiprogesterone up-regulates estrogen receptors in the endometrium of women using Norplant: a pilot study.
作者: Anna F Glasier.;Hong Wang.;Jane E Davie.;R W Kelly.;Hilary O D Critchley.
来源: Fertil Steril. 2002年77卷2期366-72页
To determine the effect of a single dose of mifepristone (200 mg) on endometrial estrogen and progesterone receptors in Norplant users.
2262. The effect of high doses of folic acid on the overexpression of ornithine decarboxylase and S-adenosylmethionine content in human colon adenomatous polyps.
作者: Bukin YUV.;V A Draudin-Krylenko.;A A Levchuk.;B K Poddubniy.;S T Mazurov.
来源: Ann N Y Acad Sci. 2001年952卷175-6页
It was shown that the 3-month supplementation of patients having colon polyps with folic acid (5 mg/day) led to a 35% decrease in abnormally high ornithine decarboxylase activity in polyps that was accompanied by a 43% increase of S-adenosylmethionine content in polyps.
2263. Tissue-type plasminogen activator and plasminogen activator inhibitor type-1 mRNA and their protein expression levels in human decidua after early pregnancy termination by mifepristone plus misoprostol.
To investigate the mechanism of prolonged uterine hemorrhage after terminating early pregnancy by mifepristone plus misoprostol.
2264. Does megestrol acetate down-regulate interleukin-6 in patients with cancer-associated anorexia and weight loss? A North Central Cancer Treatment Group investigation.
作者: Aminah Jatoi.;Jun-ichi Yamashita.;Jeff A Sloan.;Paul J Novotny.;Harold E Windschitl.;Charles L Loprinzi.
来源: Support Care Cancer. 2002年10卷1期71-5页
Megestrol acetate improves appetite and abrogates weight loss in some patients with advanced cancer. Moreover, preliminary studies suggest that progestational agents down-regulate interleukin-6 (IL-6), an inflammatory cytokine widely implicated in cancer-associated anorexia and weight loss. The present investigation examined the effects of megestrol acetate on IL-6 in an attempt to confirm these earlier, preliminary studies. The translational component of a large multi-institutional trial, this investigation examined 85 patients with advanced cancer and weight loss. Patients had been randomly assigned to receive megestrol acetate liquid suspension 800 mg/day + placebo tablets, or oral dronabinol tablets 2.5 mg b.i.d. + liquid placebo, or both agents. Other testing included serial physician-reported weight and patient-reported appetite and global quality of life. We found no significant differences in 1-month changes in serum IL-6 according to whether patients had been treated with megestrol acetate, dronabinol, or the combination: the mean differences +/- standard deviation were -1.52+/-4.7 pg/ml, -0.62+/-3.5 pg/ml, and -0.2+/-3.1 pg/ml, respectively (P=0.40, by one-way ANOVA). Among the patients who noted alterations in their appetite over 1 month, we observed no significant changes in IL-6. Finally, changes in serum IL-6 were not associated with shifts in weight or global quality of life. Our investigation provides no evidence that megestrol acetate down-regulates IL-6 in patients with cancer-associated anorexia and weight loss.
2265. Effects of plant stanol esters on LDL receptor protein expression and on LDL receptor and HMG-CoA reductase mRNA expression in mononuclear blood cells of healthy men and women.
Functional foods enriched with plant stanols lower atherogenic LDL cholesterol concentrations. This effect is caused at least partly by a decreased intestinal cholesterol absorption. It has been suggested that LDL production is reduced after plant stanol consumption, but it is unknown whether LDL receptor expression is affected and contributes to the LDL-lowering effect of plant stanols. Markers for endogenous cholesterol synthesis (lathosterol) increase, but it is not known how this higher cholesterol synthesis is regulated at the molecular level. In a double-blind placebo controlled trial, we have found that compared with the control group (N=15), daily consumption of 3.8-4.0 g plant stanol esters (N=29) for 8 weeks increased LDL receptor mRNA levels in human mononuclear blood cells by 43% (P=0.003). LDL receptor protein concentrations on the surface of monocytes and T lymphocytes increased by 37% (P=0.003) and 25% (P=0.013), suggesting an increased translation. This increased protein expression appeared to be functional, since changes in serum LDL cholesterol correlated negatively with changes in LDL receptor mRNA levels (r=-0.361; P=0.015) and changes in LDL receptor protein expression in monocytes (r=-0.440; P<0.001) and T lymphocytes (r=-0.307; P=0.018). Based on these results, we suggest that the higher LDL receptor expression contributed to a lowered LDL formation along the apoB cascade. Whole body cholesterol synthesis increased, as indicated by the rise in serum cholesterol-standardized lathosterol concentrations, but the 34% increased HMG-CoA reductase mRNA concentrations did not reach statistical significance. Nor did it correlate significantly with changes in serum cholesterol-standardized lathosterol concentrations. This suggests that HMG-CoA reductase may be only partly regulated at a transcriptional level.
2266. Low-dose theophylline does not exert its anti-inflammatory effects in mild asthma through upregulation of interleukin-10 in alveolar macrophages.
作者: B Oliver.;K Tomita.;A Keller.;G Caramori.;I Adcock.;K F Chung.;P J Barnes.;S Lim.
来源: Allergy. 2001年56卷11期1087-90页
There is accumulating evidence that theophylline has anti-inflammatory or immunomodulatory effects. This may be, in part, mediated via an upregulation in the production of the anti-inflammatory cytokine interleukin (IL)-10. We determined whether low-dose theophylline (LDT) would increase the production of IL-10, and attenuate the production of proinflammatory cytokines by alveolar macrophages.
2267. Pulsatile iv infusion of recombinant human LH in leuprolide-suppressed men unmasks impoverished Leydig-cell secretory responsiveness to midphysiological LH drive in the aging male.
The present investigation tests the clinical hypothesis that Leydig-cell responsiveness to pulsatile and midphysiological LH drive is impaired in older men. To this end, we implemented a novel clinical investigative paradigm consisting of preadministration of an LH-down-regulating dose (3.75 mg) of leuprolide acetate followed, 3-4 wk later, by controlled challenge of the testis, with pulsatile iv infusions of saline vs. recombinant human (rh) LH. Based on a preliminary dose-finding experiment, we evaluated LH action in 8 young (ages, 18-25 yr) and 7 older (ages, 60-85 yr) volunteers by infusing eight consecutive 6-min squarewave pulses of saline or 50 IU rhLH iv every 2 h. Analyses were carried out 48 or 72 h apart in a prospective, randomly assigned, double-blind, within-subject cross-over design. Serum concentrations of T (RIA) and LH (immunoradiometric assay) were measured in blood sampled every 10 min concurrently. Leuprolide injection suppressed pre-LH-infusion (0800 h baseline) serum T concentrations (pooled mean +/- SEM) markedly in both age groups (P < 10(-3)); namely, to 40 +/- 20 ng/dl (young) and 12 +/- 3.1 ng/dl (older; P < 0.05 vs. young) (to convert to nM, multiply by 0.0347). Successive iv pulses of rhLH stimulated T output, over time, to an asymptotic maximum of 166 +/- 42 ng/dl in young men (P = 0.0008 vs. saline) and 57 +/- 9.8 ng/dl in older subjects (P = NS vs. saline, and P < 0.05 vs. young). Further regression analyses identified significant reductions of both the initial rate and maximum of the time-dependent incremental rise in LH-driven serum T concentrations in older men. In contrast, infused serum LH concentrations, distribution volumes, and calculated LH half-lives were comparable in the two age cohorts. We conclude that older men manifest both a delayed initial and reduced maximal serum T concentration rise compared with young men exposed to identical controlled midphysiological pulsatile LH drive.
2268. Comparison of GH, IGF-I, and testosterone with mRNA of receptors and myostatin in skeletal muscle in older men.
作者: T J Marcell.;S M Harman.;R J Urban.;D D Metz.;B D Rodgers.;M R Blackman.
来源: Am J Physiol Endocrinol Metab. 2001年281卷6期E1159-64页
Growth hormone (GH), insulin-like growth factor I (IGF-I), and testosterone (T) are important mediators of muscle protein synthesis, and thus muscle mass, all of which decline with age. We hypothesized that circulating hormones would be related to the transcriptional levels of their respective receptors and that this expression would be negatively related to expression of the myostatin gene. We therefore determined content of mRNA transcripts (by RT-PCR) for GH receptor (GHR), IGF-I, androgen receptor (AR), and myostatin in skeletal muscle biopsy samples from 27 healthy men >65 yr of age. There were no significant relationships between age, lean body mass, or percent body fat and transcript levels of GHR, IGF-I, AR, or myostatin. Moreover, there were no significant correlations of serum GH, IGF-I, or T with their corresponding target mRNA levels (GHR, intramuscular IGF-I, or AR) in skeletal muscle. However, GHR was negatively correlated (r = -0.60, P = 0.001) with myostatin mRNA levels. The lack of apparent relationships of muscle transcripts with their respective ligands in healthy older adults suggests that age-related deficits in both GH and T may lead to an increase in myostatin expression and a disassociation in autocrine IGF-I effects on muscle protein synthesis, both of which could contribute to age-related sarcopenia.
2269. Effects of indomethacin on the L-selectin expression in humans.
Based on an in vitro study and an uncontrolled in vivo trial we examined the effects of indomethacin on the expression of L-selectin by leukocytes in healthy volunteers. Eight subjects received infusions of 0.7 mg/kg indomethacin and placebo t.i.d. (three times daily) in a randomized, controlled trial. Indomethacin decreased the mean fluorescence intensity of the L-selectin expression on isolated neutrophils incubated with toxic indomethacin concentrations. However, indomethacin did not lower the L-selectin expression in whole blood or in-vivo. Thus, therapeutic doses of the cyclo-oxygenase inhibitor indomethacin do not lower the L-selectin expression on leukocytes. Hence, the inhibition of cyclo-oxygenase cannot explain the previously observed dexamethasone-induced decrease in L-selectin.
2270. Interferon-beta therapy downregulates the anti-apoptosis protein FLIP in T cells from patients with multiple sclerosis.
Interferon-beta reduces clinical exacerbations in multiple sclerosis (MS) through several immunomodulatory mechanisms that may involve augmentation of programmed cell death (apoptosis) of T lymphocytes. The anti-apoptosis protein FLIP (Fas-associated death domain-like interleukin-1beta-converting enzyme inhibitory protein) has been recently identified as a potent regulator of T lymphocyte susceptibility to apoptosis. In a prospective study, we evaluated the expression of FLIP and other apoptosis regulatory proteins in ex vivo activated T lymphocytes from MS patients, before and serially after treatment with interferon-beta. We also investigated the long-term effects of interferon-beta on T cell apoptosis in a cross-sectional study of MS patients receiving chronic drug therapy. Treatment with interferon-beta reduced the expression of FLIP isoforms in activated T lymphocytes. This reduced expression correlated with augmented T cell susceptibility to apoptosis and with clinical response to treatment. In contrast, interferon-beta therapy did not alter cellular expression of the anti-apoptotic protein Bcl-2. This downregulatory effect of interferon-beta on cellular FLIP expression was maintained following long-term therapy. Our findings suggest that interferon-beta therapy exerts a regulatory effect on peripheral T lymphocytes through a pro-apoptosis mechanism that involves the downregulation of cellular FLIP expression.
2271. The effects of St John's wort (Hypericum perforatum) on human cytochrome P450 activity.
作者: Z Wang.;J C Gorski.;M A Hamman.;S M Huang.;L J Lesko.;S D Hall.
来源: Clin Pharmacol Ther. 2001年70卷4期317-26页
St John's wort (Hypericum perforatum) is a popular over-the-counter dietary supplement and herbal remedy that has been implicated in drug interactions with substrates of several cytochrome P450 (CYP) isozymes. The effect of St John's wort on CYP activity in vivo was examined with a probe drug cocktail.
2272. Influence of IFN-alpha on plasma erythropoietin levels in patients with hepatitis B virus-associated chronic active hepatitis.
The influence of 3-month interferon-alpha (IFN-alpha) treatment on plasma erythropoietin (EPO) concentration in patients with chronic active hepatitis (CAH) induced by hepatitis B virus (HBV) infection was investigated. The study was carried out in 44 nonanemic patients divided into two groups: CAH B, 30 subjects not treated with IFN-alpha, and CAH B-IFN, 14 subjects treated with IFN-alpha for the first 3 months of the study (5 MU/m(2) body surface subcutaneously (s.c.) three times per week). In all patients, blood samples were taken at the beginning of the study (0) and after 1, 2, 3, 6, 9, and 12 months of observation. At the beginning, plasma EPO levels in the CAH B (27.8 +/- 2.21 mU/ml) and CAH B-IFN (27.3 +/- 3.04 mU/ml) groups did not differ significantly from each other and were significantly higher (p < 0.0001) than in healthy subjects (10.4 +/- 1.06 mU/ml). In patients in the CAH B group, plasma EPO concentrations did not change significantly during the whole observation period. In patients in the CAH B-IFN group, a transient, significant increase in plasma EPO level was found. The highest plasma EPO concentration in this group was noted after the third month of treatment (41.1 +/- 3.41 mU/ml). In conclusion, patients with CAH induced by HBV infection are characterized by increased plasma EPO concentrations, and IFN-alpha treatment in these patients causes a transient increase in the plasma EPO level.
2273. Drug-drug interaction studies with mirtazapine and carbamazepine in healthy male subjects.
In two studies, the effects of the potentially interacting drugs mirtazapine and carbamazepine on their pharmacokinetics have been investigated. Subjects were treated with carbamazepine combined with placebo for 21 days and subsequently with carbamazepine combined with mirtazapine for another 7 days (Study A) or with mirtazapine combined with placebo for 7 days and subsequently mirtazapine combined with carbamazepine for another 21 days (Study B). Pharmacokinetic results indicate that carbamazepine decreased significantly AUC and Cmax values for mirtazapine and increased values for demethyl-mirtazapine Cmax. Mirtazapine had no effect on carbamazepine pharmacokinetic parameters, but did lower carbamazepine-10,11-epoxide levels. Mirtazapine did not affect the single dose kinetics or the enzyme inducing properties of carbamazepine. VAMRS alertness scores reflected the somnolence-inducing effects of carbamazepine and mirtazapine and psychometric test results revealed impairment of specific tasks. The combination was safe and routine laboratory testing did not reveal clinically relevant abnormalities. The dose of mirtazapine in patients on carbamazepine may have to be increased for optimal antidepressant efficacy.
2274. Chronic dosing of oltipraz in people at increased risk for colorectal cancer.
作者: C E Szarka.;K S Yao.;G R Pfeiffer.;A M Balshem.;S Litwin.;H Frucht.;E B Goosenberg.;P F Engstrom.;M L Clapper.;P J O'Dwyer.
来源: Cancer Detect Prev. 2001年25卷4期352-61页
The dithiolethione oltipraz is being developed as a chemopreventive agent for many malignancies, including colorectal cancer, on the basis of its in vivo protective activity against chemically induced tumors in a variety of animal models. This protection has been associated with an enhanced capacity to detoxify reactive carcinogens and, more recently, with increased DNA repair. In a previous single-dose study, elevated detoxification gene expression was observed in the days after oltipraz dosing. Now, in this clinical study, we evaluated the effects of oltipraz when given over a 3-month period. Fourteen individuals with increased risk for colorectal cancer were randomly assigned to one of two oral doses (125 or 250 mg/m2) of oltipraz twice weekly for 12 weeks. Two of seven subjects at the 250 mg/m2 dosage required dose reductions, owing to significant fatigue. The 125 mg/m2 dose level was well tolerated by all patients. Blood or colon tissue (or both) for evaluation of glutathione, glutathione S-transferase, DT-diaphorase activity, and DT-diaphorase mRNA expression were obtained prior to treatment and at weeks 6, 12, and 16. No significant modulation of phase II detoxification enzymes was seen at either dose studied during this period. Phase II trials evaluating a tolerable regimen of oltipraz (as demonstrated in this study) and other possible mechanisms that may be responsible for the protective activity of oltipraz should be pursued.
2275. Dietary supplementation with the anti-tumour promoter quercetin: its effects on matrix metalloproteinase gene regulation.
Dietary modification, especially the consumption of larger amounts of fruits and vegetables can act to decrease the risk of a variety of human cancers. Quercetin, a bioflavonoid widely distributed in fruits and vegetables has been shown to have a chemoprotective role in cancer, through complex effects on signal transduction involved in cell proliferation and angiogenesis. In this study we examined the effects of dietary supplementation of quercetin (30 mg per day) incorporated into a black currant drink. Healthy male subjects aged between 33 and 64 years (mean=47.1 years) received either quercetin or placebo for 14 days. Blood samples were taken at baseline and upon completion of the study and analysed for full blood count, matrix metalloproteinase-2 (MMP-2), tissue inhibitor of matrix metalloproteinse-1 and -2 (TIMP-1 and -2) plasma levels using ELISA techniques. RNA was extracted from the peripheral blood lymphocytes and reverse transcriptase-polymerase chain reaction (RT-PCR) carried out for MMP-2 and TIMP-1, TIMP-2 gene expression determination. Supplementation of the diet with quercetin did not alter the MMP-2 or TIMP-2 gene transcription or plasma protein levels of the healthy subjects in this study. The TIMP-1 gene transcription and plasma protein levels (311+/-70 ng/ml at baseline to 183+/-35 ng/ml post-supplementation, P<0.05) of the subjects in this study were, however, significantly decreased following quercetin supplementation. This is an interesting result, as there is some controversy over the functions of TIMP-1 in tumour progression. In certain model systems, artificially increased TIMP-1 levels prevent or decrease tumour growth. However, in other studies high levels of TIMP-1 have been correlated with aggressive disease and poor prognosis in patients with certain malignancies. This study has outlined a potential role for the anti-tumour promoter quercetin as a dietary mediator of the carcinogenic cascade.
2276. Effects of N-(4-hydroxyphenyl)retinamide on hTERT expression in the bronchial epithelium of cigarette smokers.
作者: J C Soria.;C Moon.;L Wang.;W N Hittelman.;S J Jang.;S Y Sun.;J J Lee.;D Liu.;J M Kurie.;R C Morice.;J S Lee.;W K Hong.;L Mao.
来源: J Natl Cancer Inst. 2001年93卷16期1257-63页
Telomerase activation plays a critical role in tumorigenesis. To determine the role of telomerase in early lung carcinogenesis and as a potential biomarker in chemoprevention trials, we analyzed the expression of the human telomerase reverse transcriptase catalytic subunit (hTERT) in bronchial biopsy specimens from cigarette smokers who were enrolled in a randomized, double-blinded, placebo-controlled chemoprevention trial of N-(4-hydroxyphenyl)retinamide (4-HPR).
2277. Modulation of the cytochrome P450-mediated metabolism of ifosfamide by ketoconazole and rifampin.
作者: T Kerbusch.;R L Jansen.;R A Mathôt.;A D Huitema.;M Jansen.;R E van Rijswijk.;J H Beijnen.
来源: Clin Pharmacol Ther. 2001年70卷2期132-41页
The autoinducible metabolic transformation of the anticancer agent ifosfamide involves activation through 4-hydroxyifosfamide to the ultimate cytotoxic ifosforamide mustard and deactivation to 2- and 3-dechloroethylifosfamide with concomitant release of the neurotoxic chloroacetaldehyde. Activation is mediated by cytochrome P450 (CYP) 3A4 and deactivation by CYP3A4 and CYP2B6. The aim of this study was to investigate modulation of the CYP-mediated metabolism of ifosfamide with ketoconazole, a potent inhibitor of CYP3A4, and rifampin (INN, rifampicin), an inducer of CYP3A4/CYP2B6.
2278. Changes in intratumoral thymidylate synthase (TS) and dihydropyrimidine dehydrogenase (DPD) mRNA expression in colorectal and gastric cancer during continuous tegafur infusion.
Thymidylate synthase (TS) is the target enzyme of 5-fluorouracil (5-FU), and dihydropyrimidine dehydrogenase (DPD) is the key enzyme in the 5-FU catabolic pathway. We wanted to determine whether the TS and DPD mRNA expression levels of gastric and colorectal cancer patients would be affected by tegafur (futrafur:FT)-based chemotherapy and whether changes in their expression might be responsible for patient outcome. Thirty-five patients with resectable advanced primary gastric cancer and 36 patients with resectable advanced primary colorectal cancer were the subjects of this study. They all underwent neoadjuvant chemotherapy with protracted infusion of FT alone or FT plus low doses of cisplatin. The TS and DPD mRNA expression levels of endoscopic biopsy specimens before chemotherapy and surgical specimens after chemotherapy were measured by TaqMan reverse transcription-PCR assay using glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as the internal standard. There was a significant difference in the DPD mRNA levels during chemotherapy in the colorectal cancers. Although the TS and DPD levels were unrelated to any conventional histopathological grade factors, colorectal cancer patients whose surgical specimens contained lower TS and DPD mRNA levels had longer disease-free intervals. The results of this study suggest that FT may affect DPD mRNA expression in colorectal cancer patients, that TS/DPD expression can be regarded as an independent prognostic factor, and that colorectal cancer patients with low TS and low DPD mRNA are candidates for FT-based adjuvant chemotherapy. In addition, quantitative analysis of the change in TS/DPD mRNA in surgical specimens during FT-based chemotherapy might be a more accurate means of predicting the post-operative disease-free interval of colorectal cancer patients than analysis of endoscopic specimens before chemotherapy. There also seems to be a relation between regulation of TS and DPD during FT chemotherapy. Elucidation of the mechanisms regulating TS and DPD mRNA expression might make it possible to predict sensitivity and/or toxicity to FT.
2279. Effect of aerobic exercise on behavioral and neuroendocrine responses to meta-chlorophenylpiperazine and to ipsapirone in untrained healthy subjects.
作者: A Broocks.;T Meyer.;C H Gleiter.;U Hillmer-Vogel.;A George.;U Bartmann.;B Bandelow.
来源: Psychopharmacology (Berl). 2001年155卷3期234-41页
Several clinical studies suggest antidepressive and anxiolytic effects of regular aerobic exercise.
2280. Effects of hydroxyurea on extrachromosomal DNA in patients with advanced ovarian carcinomas.
作者: E Raymond.;S Faivre.;G Weiss.;J McGill.;K Davidson.;E Izbicka.;J G Kuhn.;C Allred.;G M Clark.;D D Von Hoff.
来源: Clin Cancer Res. 2001年7卷5期1171-80页
In vitro low concentrations of hydroxyurea eliminate double-minute chromosomes (dmins) containing amplified drug-resistance genes and oncogenes from cancer cells. This clinical trial investigated whether a noncytotoxic dose of oral hydroxyurea could reduce the number of dmins in cancer cells in patients with advanced ovarian carcinomas.
|