Synthesis and biological evaluation of 3-(prop-2-enyl)- and 3-(prop-2-ynyl)pyrrolidine-2,5-dione derivatives as potential aromatase inhibitors

3-(4'-Aminophenyl)pyrrolidine-2,5-dione (WSP3), a known reversible inhibitor of P450 aromatase, was modified using molecular graphics and our model of reversible inhibitor and substrate binding to resemble 10 beta-prop-2-ynylestr-4-ene-3,17-dione (PED), a mechanism-based inactivator of the enzyme. The analogues prepared were 3-substituted 3-(prop-2-enyl) or 3-(prop-2-ynyl) pyrrolidine-2,5-diones and their N-alkyl derivatives. The reported compounds demonstrated no irreversible (time-dependent) inhibition of the human placental P450 aromatase enzyme. However, some reversible activity was seen in several of the 3-(prop-2-ynyl) compounds.

A dapsone-induced blood dyscrasia in the mouse: evidence for the role of an active metabolite

In the female mouse, dapsone (50-500 mg kg-1, p.o.) caused a dose-related methaemoglobinaemia which peaked at 0.5-1 h with recovery to baseline values occurring by 4 h. Cimetidine (100 mg kg-1, p.o.), a known inhibitor of several hepatic P450 isozymes administered 1 h before dapsone, prevented the methaemoglobinaemia. In-vitro, dapsone required activation by mouse hepatic microsomes to cause methaemoglobin formation in mouse erythrocytes and cytotoxicity to human mononuclear leucocytes. In both instances, the toxic effects were markedly reduced by cimetidine. Daily dosing of mice with dapsone (50 mg kg-1, p.o.) for 3 weeks induced a blood dyscrasia, characterized by a fall of platelet and white blood cell counts, which was inhibited by cimetidine (100 mg kg-1, p.o. daily). It is concluded that an active metabolite of dapsone arising from a P450-dependent pathway is involved in the genesis not only of the methaemoglobinaemia but also the blood dyscrasia arising from repeated administration of the drug in this species.

Metabolism of beclamide after a single oral dose in man: quantitative studies

A simple reverse phase HPLC assay is described for the determination of the anticonvulsant compound, beclamide and its 3- and 4-hydroxyphenyl metabolites in urine. Following oral administration of 1 g beclamide to a panel of healthy volunteers, less than 0.4% of the dose was excreted unchanged in the 24-h urine and unconjugated 3- and 4-hydroxyphenyl metabolites were not detected. Based on examination of the urine after incubation with beta-glucuronidase and aryl sulphatase, it was found that these hydroxyl metabolites were excreted as both glucuronide and sulphate conjugates. For each metabolite the glucuronide was the major excretory product (approximately 10:1). The 24-h excretion of the combined conjugated metabolites was 7% (for the 3-hydroxy metabolite) and 24% (for the 4-hydroxy metabolite) of the dose. Approximately 22% of the administered dose of beclamide was excreted as hippuric acid. In view of the simplicity of assay, beclamide may be a useful tool substance with which to examine factors influencing the xenobiotic metabolic pathways of benzene ring hydroxylation and glucuronide and sulphate conjugation in man.

The demand for graduate education in health services administration: a case study

This article documents research into the demand for graduate education in health services administration/management with a case study model. Research included background information on the profession, the history of graduate education in health services administration, health care administrator demographics and their perceptions of the demand for graduate-prepared professionals and their own educational needs, most appropriate degree to offer, and curriculum content. The findings support the trend toward a balance between specific and general health care business skills in graduate education. Other schools may benefit from the student profile, program delivery, appropriate degree information, and curriculum content findings as well as the research instrument design and methodology when assessing and planning graduate programs in health services administration/management.

1-pentyl-3-(4-aminophenyl)pyrrolidine-2,5-dione, a selective aromatase inhibitor: in vivo studies

1-Pentyl, 1-hexyl and 1-heptyl-3-(4-aminophenyl)pyrrolidine-2,5-dione, potent inhibitors of aromatase, lower oestrogen levels in PMSG-stimulated female rats in a comparable manner to the inhibitor aminoglutethimide (AG) used clinically for the treatment of breast cancer. Pharmacokinetic studies in the rat show t 1/2 values for the 1-hexyl compound and AG of 1.8 and 5.5 h respectively. In 4 tests for CNS-depressant activity the overall order of activity was AG > 1-heptyl = 1- hexyl >> 1-pentyl. The 1-pentyl compound has less tendency than AG to depress white cell and platelet counts in mice and overall is the drug candidate for further studies.

Some 1-, and 3-substituted 3-(4'-aminophenyl)pyrrolidine-2,5-diones as selective inhibitors of aromatase

1-Alkyl-3-(4'aminophenyl)pyrrolidine-2,5-diones (7,R = C3H7-C7H15) are potent inhibitors of aromatase in vitro, the 1-hexyl (Ki = 62nM) being about 100-fold more potent than aminoglutethimide (AG), and more selective in their ratio of aromatase:CSCC inhibitory potency. The 1-pentyl, 1-hexyl and 1-heptyl derivatives are more stable to liver microsomal metabolism in vitro than AG possibly due to inhibition of the liver cytochrome P450s. 1,3-Dialkyl-3(4'-aminophenyl)pyrrolidine-2,5-diones (9) have been synthesised by a novel method. Although the higher homologues (di-pentyl and di-hexyl) are more potent in vitro as inhibitors of aromatase than AG, they are less active than their 1-alkyl counterparts with the same alkyl substituent.

Infantile nephronophthisis

Juvenile nephronophthisis is a common cause of end stage renal failure in children and adolescents. The early occurrence with rapid progression to advanced renal failure has not previously been described. In this report we present three babies in whom failure to thrive, dehydration and a renal concentrating defect presented soon after birth; they were subsequently investigated for renal failure during the first year of life. In two cases the association with congenital hepatic fibrosis was noted. A family history of nephronophthisis was not present but the parents were consanguineous and one sibling had died in infancy.

Agnogenic myeloid metaplasia: role of splenectomy

The splenomegaly associated with myelofibrosis and agnogenic myeloid metaplasia should not be considered a manifestation of the fundamental proliferative process, nor should it be considered as necessarily compensatory for reduced marrow haematopoiesis.

In deserving cases splenectomy may cause an improvement in the patient's general and haematopoietic status. Removal of the source of functional hypersplenism, causing haemolytic episodes and thrombocytopenia, results in marked amelioration in the clinical condition with reduction in the magnitude and frequency of replacement blood transfusion.

The massive size of the spleen associated with this condition may not only cause local pain and discomfort but may lead to traumatic or spontaneous rupture.

Consideration of two cases studied by the authors indicates that marked clinical improvement may be associated with splenectomy in selected cases of agnogenic myeloid metaplasia.