共查询到20条相似文献,搜索用时 7 毫秒
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N-(4-Hydroxyphenyl)-retinamide (4-HPR; Fenretinide) is a synthetic retinoid which is undergoing investigation as a cancer chemopreventive agent. However, 4-HPR alters vitamin A kinetics and reduces the concentration of plasma retinol. We have conducted studies to examine the effects of 4-HPR on the activity of the enzyme lecithin:retinol acyltransferase (LRAT). This enzyme is implicated in the absorption and storage of vitamin A and is regulated, in liver, by vitamin A nutritional status. To determine whether 4-HPR, like retinoic acid, is able to induce liver LRAT activity, vitamin A-deficient rats having negligible liver LRAT activity were treated with single doses of 4-HPR (0.02-2.5 mg) and liver homogenates were assayed for LRAT activity using 3H-retinol bound to the cellular-retinol binding protein, CRBP, as substrate. Treatment with 4-HPR resulted in a dose- and time-dependent increase in liver LRAT activity which reached a maximum at 24 h. The activity of LRAT assayed in vitro and of hepatic 3H-retinyl ester content determined after an in vivo pulse of 3H-retinol were highly correlated (r = 0.802, P < 0.0002). When vitamin A-sufficient rats were fed a 4-HPR-supplemented diet for 30 d, LRAT activity differed significantly from control values in the liver (P < 0.0001) but not the small intestines. Changes in hepatic retinol metabolism which favor the esterification of vitamin A may be related to the mechanism by which 4-HPR alters vitamin A kinetics in vivo. 相似文献
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YF Shealy DL Hill BP Sani I Eto MM Juliana CJ Crubbs 《Canadian Metallurgical Quarterly》1998,5(4):857-860
As determined by in vitro tests, anhydroretinol, a metabolic product of retinol, was bound specifically by serum retinol-binding protein and by cellular retinol-binding protein but not by cellular retinoic acid-binding protein or the nuclear receptors, RARs and RXRs. For rats dosed with the mammary carcinogen, N-methyl-N-nitrosourea (45 mg/kg body weight) and given diets containing either the retinoid vehicle, anhydroretinol (67, 134, 268, or 536 mg/kg of diet), or retinyl acetate (328 mg/kg of diet), there were, over a 90-day observation period, no significant differences in body weights. The compound did not accumulate in liver tissue or cause an increase in hepatic levels of retinyl palmitate (potential problems observed with other retinoids). The numbers of mammary cancers were as follows: no retinoid, 4.5/rat; retinyl acetate, 2.1/rat; and increasing doses of anhydroretinol, 2.9, 3.3, 3.0, and 1.7/rat, respectively. Thus, anhydroretinol, at non-toxic levels, was effective as a preventive agent in this experimental model of breast cancer. 相似文献
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AP Tamiz ER Whittemore RM Schelkun PW Yuen RM Woodward SX Cai E Weber JF Keana 《Canadian Metallurgical Quarterly》1998,8(2):199-200
A series of N-(2-phenethyl)cinnamides was synthesized and assayed for antagonism at three N-methyl-D-asparate (NMDA) receptor subtypes (NR1A/2A-C). N-(2-(4-hydroxyphenyl)ethyl)-4-chlorocinnamide (6) was identified as a highly potent and selective antagonist of the NR1A/2B subtype. 相似文献
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I Ichihara 《Canadian Metallurgical Quarterly》1977,181(3):327-337
The fine structure of the secretory epithelial cells of rat's ventral prostate has been studied following organ culture. Culturing with either testosterone or insulin alone, and with the two hormones combined, were carried out to investigate how insulin modifies the action of testosterone on the maintenance of cellular integrity. After 4 days in hormone-free culture, the secretory epithelial cells showed signs of cellular atrophy and regression, involving loss of the apical microvilli, absence of the apical secretory vacuoles, atrophy of the Golgi apparatus, decrease in rough endoplasmic reticulum and the appearance of autophagic vacuoles. The presence in the medium of either testosterone or insulin alone, or combined, prevented cellular atrophy and regression. The best maintenance of cellular integrity was obtained in a culture containing both hormones. The effects of insulin was approximately equivalent to those of testosterone in the maintenance of cellular integrity. 相似文献
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ND Lambadjieva 《Canadian Metallurgical Quarterly》1998,20(8):673-677
A 31-year old woman with acquired immunodeficiency syndrome (AIDS) and a history of lymphoma presented with a 2-week history of severe hyperthyroid symptoms and new-onset neck swelling. On physical examination, she was found to be clinically hyperthyroid, with a markedly enlarged, diffuse, tender goiter. Thyroid function testing confirmed hyperthyroidism. The patient had a rapidly deteriorating clinical course and died within days of her presentation. At autopsy, near-complete replacement of the thyroid gland with anaplastic large cell lymphoma was found, without coexisting infectious or autoimmune processes in the gland. This is the first case report of a patient with AIDS developing symptomatic thyroid involvement by lymphoma, and one of only a few case reports of hyperthyroidism associated with lymphoma in general. 相似文献
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T Spruss S Schertl MR Schneider R Gust K Bauer H Sch?nenberger 《Canadian Metallurgical Quarterly》1993,119(12):707-716
The platinum complex [meso-1,2-bis(2,6-dichloro-4-hydroxyphenyl)- ethylenediamine]dichloroplatinum(II),K, was tested for its antitumor activity on hormone-sensitive tumor models under peroral administration. The resorption from the gastrointestinal tract was proved by determining the estrogenic effect of K in a dose/activity study using the immature-mouse uterine weight test. In comparison to the subcutaneous injection, a tenfold peroral dose was administered to achieve identical effects. By peroral treatment of the hormone-sensitive MXT(M3.2) mammary carcinoma of the mouse with K an almost complete inhibition of the tumor growth was obtained. This effect was superior to that of subcutaneously applied cisplatin and significantly better than that obtained by perorally administered ligand L at an equimolar dose, indicating that the antitumor effect is caused by the intact complex K and not by the liberated ligand L. The strong antitumor activity of perorally applied K was also demonstrated on the hormone-sensitive Noble Nb-R prostatic carcinoma of the rat. Histological examinations showed that the platinum complex K did not cause cisplatin-like kidney damage or irritations of gastric or intestinal mucosa when given perorally. 相似文献
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Effects of ifenprodil tartrate, a potent vasodilator, on the autonomic, peripheral and central nerve system were studied in experimental animals. In isolated vas deferens of guinea pigs, the contraction in response to noradrenaline and sympathetic nerve stimulation was competetively antagonized by ifenprodil 10(-7)--10(-5) M (pA2: 7.69 against noradrenaline). Ifenprodil (50 approximately 1,000 mug/kg i.v.) inhibited the contraction of cat nictitating membrane and dog urinary bladder induced by sympathetic nerve stimulation. Ifenprodil (250 approximately 1,000 mug/kg i.v.) lowered adrenaline-induced lethality (ED50: 360 mug/kg). The drug produced a hypermotility of guinea pig uterus, and showed a transient hypertonus of dog gut which was abolished by atropine. Ifenprodil (10 approximately 20 mg/kg i.v.) inhibited the propulsion of charcoal meal in mice. In Shay rats, more than 10 mg/kg i.m. of the drug inhibited the secretion of acid gastric juice and the ulceration. Ifenprodil showed a potent local anesthetic action in the guinea pig cornea and skin. The spontaneous EEG of rabbits showed a resting pattern (0.25 approximately 2 mg/kg i.v.) followed by an arousal pattern (5 approximately 10 mg/kg). Ifenprodil (20 approximately 100 mg/kg p.o.) potentiated a hypnosis induced by barbital, and potentiated pentylenetetrazol, strychnine and picrotoxin induced convulsion. The drug (20 and 100 mg/kg p.o.) lowered the body temperature of rats. From these results it is concluded that ifenprodil produces a blocking action of alpha-adrenoceptors in various smooth muscle preparations and a direct relaxation of the smooth muscle itself without affecting the motor and central nerve systems. 相似文献
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We describe a sensitive and precise high-pressure liquid-chromatographic method for measurement of total 5-(4-hydroxyphenyl)-5-phenylhydantoin, a metabolite of phenytoin, in urine. An aliquot of urine, containing 5-(4-methylphenyl)-5-phenylhydantoin as an internal standard, is processed and chromatographed. The metabolite and internal standard are identified from their retention times and quantitated from their relative response factors. The metabolite is separated from normal urine constituents and internal standard in less than 8 min. The sensitivity of the method is such that after the usual dose it can be measured in 0.5 ml of urine; the lower limit of detection is 300 ng. 相似文献
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JB Thomas MJ Fall JB Cooper RB Rothman SW Mascarella H Xu JS Partilla CM Dersch KB McCullough BE Cantrell DM Zimmerman FI Carroll 《Canadian Metallurgical Quarterly》1998,41(26):5188-5197
A three-component library of compounds was prepared in parallel using multiple simultaneous solution-phase synthetic methodology. The compounds were biased toward opioid receptor antagonist activity by incorporating (+)-(3R,4R)-dimethyl-4-(3-hydroxyphenyl)piperidine (a potent, nonselective opioid pure antagonist) as one of the monomers. The other two monomers, which included N-substituted or unsubstituted Boc-protected amino acids and a range of substituted aryl carboxylic acids, were selected to add chemical diversity. Screening of these compounds in competitive binding experiments with the kappa opioid receptor selective ligand [3H]U69,593 led to the discovery of a novel kappa opioid receptor selective ligand, N-?(2'S)-[3-(4-hydroxyphenyl)propanamido]-3'-methylbutyl?-(3R, 4R)-dimethyl-4-(3-hydroxyphenyl)piperidine (8, RTI-5989-29). Additional structure-activity relationship studies suggested that 8 possesses lipophilic and hydrogen-bonding sites that are important to its opioid receptor potency and selectivity. These sites appear to exist predominantly within the kappa receptor since the selectivity arises from a 530-fold loss of affinity of 8 for the mu receptor and an 18-fold increase in affinity for the kappa receptor relative to the mu-selective ligand, (+)-N-[trans-4-phenyl-2-butenyl]-(3R, 4R)-dimethyl-4-(3-hydroxyphenyl)piperidine (5a). The degree of selectivity observed in the radioligand binding experiments was not observed in the functional assay. According to its ability to inhibit agonist stimulated binding of [35S]GTPgammaS at all three opioid receptors, compound 8 behaves as a mu/kappa opioid receptor pure antagonist with negligible affinity for the delta receptor. 相似文献
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SK Hong DK Anestis MA Valentovic JG Ball PI Brown RT Wang GO Rankin 《Canadian Metallurgical Quarterly》1998,54(8):613-632
N-(3,5-Dichlorophenyl)succinimide (NDPS) is an agricultural fungicide that induces nephrotoxicity as its major toxicity. NDPS is also a more potent nephrotoxicant in female than in male rats. The purpose of this study was to examine the nephrotoxic potential of the two NDPS metabolites N-(3,5-dichlorophenyl)-2-hydroxysuccinimide (NDHS) and N-(3,5-dichlorophenyl)-2-hydroxysuccinamic acid (2-NDHSA) in age-matched male and female Fischer 344 rats to determine if gender differences exist for the nephrotoxicity induced by the two NDPS metabolites. Rats (4 per group) were administered a single intraperitoneal (ip) injection of NDHS or 2-NDHSA (0.025 or 0.05 mmol/kg) or vehicle, and renal function was monitored for 48 h. Neither compound induced significant nephrotoxicity in male rats at the doses tested. However, in female rats both metabolites induced marked nephrotoxicity at the 0.05 mmol/kg dose level, and treatment with 0.025 mmol/kg 2-NDHSA induced some changes in renal function (transient diuresis, transient proteinuria, decreased organic ion accumulation). Little effect on renal function was induced in females by treatment with 0.025 mmol/kg NDHS. At toxic levels in female rats, the renal lesions were located primarily in the S2 and S3 segments of the proximal tubule. These results indicate that, like the parent compound, gender differences exist in the nephrotoxic potential of NDHS and 2-NDHSA. The results also suggest that in females, as in males, NDPS nephrotoxicity is mediated via NDHS and/or 2-NDHSA. However, it is not clear if the ultimate nephrotoxicant species following NDPS exposure is different in males and females or if the same ultimate nephrotoxicant species is produced in both species but handled differently by male and female kidneys. Thus, further studies are needed to determine the exact nature of the ultimate nephrotoxicant species and the mechanisms of the observed gender differences. 相似文献
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CS Cooper PJ Perry AE Sparks JH MacIndoe WR Yates RD Williams 《Canadian Metallurgical Quarterly》1998,159(2):441-443
PURPOSE: We investigate and define the effects of exogenous testosterone on the normal prostate. MATERIALS AND METHODS: A total of 31 healthy volunteers 21 to 39 years old were randomized to receive either 100, 250 or 500 mg. testosterone via intramuscular injection once a week for 15 weeks. Baseline measurements of serum testosterone, free testosterone and prostate specific antigen (PSA) were taken at week 1. Semen samples were also collected for PSA content and prostate volumes were determined by transrectal ultrasound before testosterone injection. Blood was then drawn every other week before each testosterone injection for the 15 weeks, every other week thereafter until week 28 and again at week 40. After the first 15 weeks semen samples were again collected, and prostate volumes were determined by repeat transrectal ultrasound. RESULTS: Free and total serum testosterone levels increased significantly in the 250 and 500 mg. dose groups. No significant change occurred in the prostate volume or serum PSA levels at any dose of exogenous testosterone. Total semen PSA levels decreased following administration of testosterone but did not reach statistical significance. CONCLUSIONS: Despite significant elevations in serum total and free testosterone, healthy young men do not demonstrate increased serum or semen PSA levels, or increased prostate volume in response to exogenous testosterone injections. 相似文献
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研究了在TritonX-100存在下,Pt(Ⅱ)与二溴羟基卟啉的显色反应。结果表明,在pH 9.4的Na_2SO_3溶液中,Pt(Ⅱ)与二溴羟基卟啉及Na_2SO_3形成1:1:2的络合物,络合物的最大吸收峰位于386nm波长处,表观摩尔吸光系数为3.76×10~5L·mol~(-1)·cm~(-1)。10 mL溶液中,Pt(Ⅱ)含量在0~4.0μg范围内符合比尔定律。本法用于催化剂和贵金属矿物中微量铂的测定,RSD为1.26%~3.76%,回收率为97.6%~98.2%。 相似文献
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JB Thomas SW Mascarella RB Rothman JS Partilla H Xu KB McCullough CM Dersch BE Cantrell DM Zimmerman FI Carroll 《Canadian Metallurgical Quarterly》1998,41(11):1980-1990
A study of the binding site requirements associated with the N-substituent of (+)-(3R,4R)-dimethyl-4-(3-hydroxyphenyl)piperidine (4) derivatives was undertaken using a set of rigid vs flexible N-substituents. The study showed that compounds 7-9 bearing the trans-cinnamyl N-substituent most closely reproduced the potency at the opioid receptor of the flexible N-propylphenyl or N-propylcyclohexyl analogues previously reported. Neither the N-substituted cis-cinnamyl nor the cis-phenylcyclopropylmethyl compounds 10 and 11, respectively, showed high affinity for the opioid receptor. However, the N-trans-phenylcyclopropylmethyl compound 12 closely approximated the affinity of compounds 7-9. Additionally, we found that free rotation of the phenyl ring is necessary for high affinity binding and mu receptor subtype selectivity as the planar N-substituted thianaphthylmethyl and benzofuranylmethyl compounds 13 and 14 had significantly lower binding affinities. Altogether, these findings suggest that the high binding affinity, selectivity, and antagonist potency of N-propylphenyl or N-propylcyclohexyl analogues of (+)-(3R, 4R)-dimethyl-4-(3-hydroxyphenyl)piperidine (4) are achieved via a conformation wherein the connecting chain of the N-substituents is extended away from piperidine nitrogen with the appended ring system rotated out-of-plane relative to the connecting chain atoms. This conformation is quite similar to that observed in the solid state for 5, as determined by single crystal X-ray analysis. Additionally, it was found that, unlike naltrexone, N-substituents bearing secondary carbons attached directly to the piperidine nitrogen of 4 suffer dramatic losses of potency vs analogues not substituted in this manner. Using a functional assay which measured stimulation or inhibition of [35S]GTP-gamma-S binding, we show that the trans-cinnamyl analogues of (+)-(3R, 4R)-dimethyl-4-(3-hydroxyphenyl)piperidine (4) retain opioid pure antagonist activity and possess picomolar antagonist potency at the mu receptor. 相似文献
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The modifications produced by 6-hydroxydopamine (6-OHDA) on the analgesic and toxic effects of morphine have been studied in mice and cats. After intracerebral injections of 6-OHDA, mice had a lower threshold for morphine-induced convulsions. Morphine analgesia assayed by the phenylquinone test was apparently antagonized in the 6-OHDA pretreated mice, but the 6-OHDA mice showed more reactivity to the phenylquinone. Intraventricular injection of 6-OHDA in cats produced an acute syndrome with mydriasis, bradycardia, bradypnea, hypothermia and EEG slowing, which subsided after several days, 6-OHDA was successful in blocking the morphine mania, but the animals died within 24 h. 相似文献
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Hepatocurative effects of mandur bhasma were studied in albino rats after induction of acute hepatitis by CCl4 liquid paraffin and CCl4 + liquid param. Recovery of the liver was studied with reference to histological architecture and differential counts of degenerated, recovering and recovered hepatocytes. Alterations in the kidney were also studied histologically. Hepatotoxins were given (s.c.) daily for 11 days. Mandur bhasma was given (po) for 7 days to normal, CCl4, liquid paraffin and CCl4 + liquid paraffin treated rats from day 12 to day 18. There were no spontaneous liver and kidney recoveries within a week after the cessation of the treatments of hepatotoxins. Mandur bhasma treatment showed conspicuous recoveries of liver and kidney within a week and total recoveries were noticed after two weeks. Biochemical alterations in lipid peroxidation, glucose-phosphatase and total proteins were studied during present work. The alterations in the histology and biochemical parameters of liver and kidney show hepatocurative potency of mandur bhasma. 相似文献
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P Macchiarini AR Chapelier I Monnet JM Vannetzel JL Rebischung J Cerrina F Parquin FL Ladurie B Lenot PG Dartevelle 《Canadian Metallurgical Quarterly》1994,57(4):966-973
Twenty-three patients with stage IIIb (T4) non-small cell lung cancer received induction chemotherapy (median, 2 cycles) with (n = 12) or without (n = 11) radiation (median, 45 Gy) before operation. Nine tumors involved the carina (n = 8) or lateral tracheal wall (n = 1), 11 were located centrally and invaded the proximal pulmonary artery (n = 6), veins (n = 3), or both (n = 2), three were apical tumors involving T4 structures, and six were associated with histologically diseased mediastinal nodes. Five complete and 18 partial responses were observed after induction treatment. Resection of all residual tumor at the primary site and involved vestiges was possible in 21 patients (91%); in two apical tumors, tumor was left behind. Nine right tracheal sleeve and 11 intrapericardial pneumonectomies and three resections of apical tumors were performed; 11 patients (48%) had radical mediastinal lymph node dissection. Complete sterilization of the primary tumor was observed in 3 patients (13%). Mean operating time was 209.3 +/- 86.8 minutes, and mean blood loss was 896.9 +/- 1031 mL. Major postoperative complications occurred in 6 patients (26%), including hemothorax requiring drainage (n = 1) or reoperation (n = 1), acute distress syndrome (n = 2), and bronchopleural fistula (n = 2), and their incidence was significantly higher (p = 0.0003) among patients receiving induction chemoradiation than among those receiving chemotherapy alone (42 versus 9%). Early (< 1 month) postoperative mortality was 8.6% (n = 2). With a median follow-up of 25 months (range, 12 to more than 39 months), the projected 3-year overall survival was 54%.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
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The rate of excretion of aldosterone radiometabolites into the bile duct cannulation, and the intravenous injection of (3H)aldosterone, was demonstrated to be markedly increased in male rats following castration. In 1 h, 72% of the injected 3H-radioactivity was excreted in the bile of castrated male rats compared with 26% in the intact male control rats. Castration of the males led to the increased biliary excretion of aldosterone metabolites and the elimination of the sex-dependence of this process in rats. The ovariectomy of female rats did not substantially increase the rate of excretion of aldosterone metabolites via the bile. Castrated male rats treated with testosterone excreted aldosterone metabolites into the bile at a slower rate. A similar treatment of ovariectomized female rats with testosterone also significantly slowed the rate of biliary excretion of the aldosterone metabolites. These findings suggest that the presence of androgens plays an important role in regulating the routes of hepatic metabolism of aldosterone and the rates of clearance of aldosterone and its metabolites from the plasma into the bile of rats. 相似文献