Functional mechanism underlying cyclooxygenase-2 expression in rat small intestine following administration of indomethacin: Relation to intestinal hypermotility

Background and Aim:  We recently reported that cyclooxygenase (COX)-2 is upregulated in the rat small intestine after administration of indomethacin, and this may be the key to non-steroidal anti-inflammatory drug (NSAID)-induced intestinal damage. The present study investigated the mechanism for COX-2 expression induced in the rat small intestine by indomethacin, in relation with ulcerogenic processes.
Methods:  Animals were given indomethacin or SC-560 p.o., and the intestinal mucosa was examined 24 h later.
Results:  Indomethacin caused hemorrhagic lesions in the small intestine, accompanied with an increase in intestinal motility, bacterial invasion and inducible nitric oxide synthase (iNOS) activity, as well as the expression of COX-2 mRNA in the mucosa. Although SC-560 did not cause any damage, this agent caused intestinal hypermotility, the bacterial invasion and the upregulation of COX-2 expression. The mucosal PGE₂ content was decreased by SC-560 at 3 h but recovered 12 h later, and this recovery of PGE₂ was attenuated by both atropine and ampicillin, in addition to rofecoxib. The intestinal hypermotility response to indomethacin was prevented by both 16,16-dimethyl PGE₂ and atropine, but not ampicillin. Yet all these agents inhibited not only the bacterial invasion but also the expression of COX-2 and iNOS activity in the intestinal mucosa following indomethacin treatment, resulting in the prevention of intestinal lesions.
Conclusion:  These results suggest that COX-2 expression in the intestinal mucosa following the administration of indomethacin is associated with intestinal hypermotility and bacterial invasion. The intestinal hypermotility caused by COX-1 inhibition may be a key to COX-2 expression after administration of NSAIDs and their intestinal ulcerogenic properties.     

Circular dichroism detection in high-performance liquid chromatography: Evaluation of the anisotropy factor

The application of a circular dichroism (c.d.) detection system in HPLC using a chiral stationary phase is presented. The simultaneous measurement of the absorbance and c.d. signal allows the evaluation of the anisotropy factor (g = Δ/) and thus the determination of the enantiomeric excess (e.e.) of the eluates. When this detection system is used in preparative chiral chromatography the collection of the enantiomeric fractions can be readily optimized.     

Syntheses of Novel Pyridazinomorphinans by Inverse Electron Demand Cycloaddition and their Binding to μ and κ Receptors

A number of novel pyridazinomorphinans have been synthesized by the inverse electron demand Diels-Alder reaction of various 3,6-disubstituted 1,2,4,5-tetrazines with enamines derived from dihydrocodeinone and with codeinone. Reduction of some of the pyridazinomorphinans did not furnish the expected pyrroloepoxymorphinans; in all cases investigated reductive cleavage of the epoxybridge was observed to yield dihydropyridazino- or pyrrolomorphinans. The structures of all new compounds were assigned by the spectral data, that of the cycloadduct of codeinone was additionally verified by X-ray crystallography. Compounds 5a, 8, 11a , and 16 have been evaluated for their affinity at μ and κ opioid receptors in radioligand binding assays. Their ability to inhibit [³H]DAMGO binding at μ and [³H]U 69.593 binding at κ receptors, respectively as compared to codeine has been found to be lower.     

THE EFFECT OF HYPERTENSIVE EPISODES AND CARDIAC HYPERTROPHY ON THE CANINE CARDIAC BAROREFLEX

1. Left ventricular (LV) hypertrophy has been implicated in the reduction of baroreflex sensitivity present in hypertension. The aim of the current study was to investigate the mean arterial pressure-heart rate reflex (MAP-HR) in a model which induced left ventricular hypertrophy but no sustained blood pressure elevation. 2. Five mongrel dogs were exposed to transient blood pressure elevation of between 20 and 30 mmHg, through hindlimb compression using a pneumatic pressure suit, for 7 h per day, 6 days per week for 6 weeks. Resting blood pressure was not altered by the 6 week hindlimb compression intervention. 3. Echocardiographically determined LV mass (mean ± s.e.m.) was 116.0 ± 7.4 g prior to hindlimb compression (baseline) and elevated to 125.4 ± 8.1 g (P= 0.003) after 6 weeks of compression. A reduction in the early (E) to late (A) transmitral diastolic flow ratio (E/A) from 1.80 ± 0.06 at baseline to 1.54 ± 0.09 (P = 0.037) after the 6 week intervention suggested that cardiac compliance was reduced. 4. The maximum gain of the MAP-HR reflex, studied using the ‘steady-state’ drug technique, when blood pressure was normal, showed a trend for reduction from 3.85 ± 0.43 beats/min per mmHg at baseline to 3.10 ± 0.45 beats/min per mmHg (P= 0.067) after 6 weeks of compression. This gain reduction became significant after β-adrenoceptor blockade with propranolol (3.13 ± 0.55 vs 2.32 ± 0.25 beats/min per mmHg; P= 0.039). Covariant analysis showed a significant inverse correlation between LV mass and maximum gain (r= 0.96; P<0.001) during the 6 week compression period. 5. The MAP-HR reflex changes in this model mimic those present in hypertension and implicate cardiac hypertrophy as one possible mediator.     

Dexfenfluramine in the treatment of severe obesity: a placebo-controlled investigation of the effects on weight loss, cardiovascular risk factors, food intake and eating behaviour.

Dexenfluramine, an effective and safe serotoninergic drug with anorectic and possible food-selection-tuning properties, was investigated in a placebo-controlled study of 1 year's duration in severe and refractory obesity. The aim of the study was to assess weight loss, and changes in cardiovascular risk factors, food intake and eating behaviour. Dexfenfluramine- and placebo-treated patients achieved a similar weight loss (greater than 10% of initial weight, by 39.5 and 30.0%, greater than 20% of initial overweight by 42.1% and 32.5% and greater than 10 kg by 41.4 and 33.3%, respectively, of the initial cohorts). Furthermore, the decreases in weight (10.7 vs. 8.0 kg), in body mass index (3.9 vs. 2.9 kg m2) and in waist/hip ratio (0.04 vs. 0.02) were not significantly different. After discontinuation of the drug, the increase in weight (2.8 vs. 1.0 kg) was significantly higher in the dexfenfluramine-treated group. Except for a borderline better effect on glucose of dexfenfluramine, both groups showed similar beneficial changes in food intake and cardiovascular risk factors. Eating behaviour in response to emotional and external stimuli was comparable in the two groups, but placebo-treated patients had to restrain their eating more in order to achieve the same weight loss. Notwithstanding the fact that weight losses and an associated amelioration of health-risk factors were of similar magnitude in dexfenfluramine- and placebo-treated patients, dexfenfluramine might have a useful role in promoting a less stressed adherence to prolonged restriction of energy intake in the severe and refractory obese subject.     

抗精神病药物治疗引起患者体质量增加及其相关因素分析

目的　探讨抗精神病药(APD)引起患者体质量增加及其相关因素。方法　对6 7例首次住院单用APD治疗的精神分裂症患者进行住院及出院后4个月的随访评估。结果　各时点体质量增加与GI评分无相关性,在出院时与BPRS、SAPS减分值有相关性,而随访期与SANS减分值有相关意义。逐步回归分析显示,在α=0 .0 5水平上,进入回归方程的因素依次为:APD品种,最大服药剂量与服药时间的积,阴性症状,病前1a最佳功能水平。结论　APD治疗中的体质量增加是与疗效无关的药物不良反应,受药物、精神症状及综合社会心理因素等方面的影响,而饮食与活动的中介作用不应低估。控制体质量增加有重要的医学及社会意义。     

TAD方案治疗急性非淋巴细胞白血病疗效的评价

采用 TAD 方案治疗急性非淋巴细胞性白血病(ANLL)12例,年龄17～47岁。总有效率为66.7%,完全缓解率(CR)为41.7%。5例获 CR 的时间是26～66天,平均53天,较国内其它方案为快。CR 时间为2～9月,平均6.2月,较其它方案又较短。TAD 方案对心脏的毒性作用轻微。TAD 方案对5例获 CR 者,于诱导治疗第一疗程后,除1例外,骨髓中白血病细胞百分比下降均不明显;但于第二疗程后,白血病细胞全部减少到骨髓有核细胞总数的20%/以下,这种现象似可作为本方案预后的观察指标。     

How adverse drug reactions can play a role in innovative drug research

We describe how adverse drug reactions (ADRs) can play an important role in pharmaceutical research and drug development. Not only do ADRs represent the risks and drawbacks associated with drugs but they can also be related to other knowledge available in pharmaceutical and medical research. We offer a model that can be used to systematically map the pathways through which ADRs can lead to innovative research. These pathways include chemical, therapeutic or pathophysiological steps that can be taken to arrive at new knowledge based on ADRs. We used the development of angiotensin-converting enzyme inhibitors, especially captopril, as a case study. The similarity between the ADR profiles of captopril and penicillamine was a starting point for further innovation. Historical analysis shows that in several instances research in the field of angiotensin-converting enzyme inhibitors has been triggered by ADRs. The model presented here might be applicable to other areas of innovative drug research.     

Antisocial personality disorder, HIV risk behavior and retention in methadone maintenance therapy

In a sample of 55 consecutive methadone maintenance admissions to our clinic, 42% were diagnosed with antisocial personality disorder (ASPD) using the National Institute of Mental Health Diagnostic Interview Schedule NIMH DIS. Individuals with ASPD exhibited greater risk for HIV infection as defined by more sexual contacts, needle use and equipment sharing. Data at 1 year follow-up were obtained on this group of patients. The objective was to compare the ASPD and non-ASPD groups with regards to demographics, drug abuse history, outcome and retention in treatment. There were no significant differences between the groups on any demographic or treatment outcome variables. Survival analysis indicated that there were no group differences in treatment retention. In conclusion, although there were no differences in treatment outcome between ASPD and non-ASPD groups it is possible that ASPD patients who drop out of treatment will be at higher risk for contracting and spreading HIV within the IV drug using population. These data also suggest that in this population the diagnosis of ASPD using primarily behavioral traits as measured in the NIMH-DIS-III, has little utility in predicting treatment outcome.     

A comparison of the effects of a macrobiotic diet and a western diet on drug metabolism and plasma lipids in man

Summary We have compared the effects of two dietary regimens with different macronutrient compositions — a macrobiotic diet and a Western diet — on drug metabolism and plasma lipids in seven healthy volunteers.The macrobiotic diet, high in carbohydrate, low in protein and fat, and devoid of animal food sources, was eaten for a ten day control period, as was the Western diet, high in calories, fat, and protein, as well as animal food sources. We determined the influences of these diets on the clearance of orally administered antipyrine, oxazepam, and methadone, as well as on plasma lipids.There was a statistically significant change in antipyrine clearance as well as in plasma LDL-cholesterol and HDL-cholesterol after the dietary periods. This suggests that the influence of dietary changes may have some effect on the clearance of therapeutic drugs. However, this is not universal and is probably important when the drug is highly dependent on the mixed-function oxidase system.