Synthesis and biological evaluation of 8-hydroxy-2,7-naphthyridin-2-ium salts as novel inhibitors of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE)

By analogy with the natural product chelerythrine, which has been identified as an inhibitor of both acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), we prepared a small series of 8-hydroxy-2,7-naphthyridin-2-ium salts. Spectroscopic analyses allowed us to elucidate the zwitterionic nature of 2,7-naphthyridin-1(7H)-ones, the neutral state of 8-hydroxy-2,7-naphthyridin-2-ium salts. Among the tested compounds, we identified dual inhibitors of AChE and BChE as well as an inhibitor showing a preferential inhibition of AChE over BChE. By in vitro characterization in combination with docking studies, we were able to identify structural features that influence the biological activity of 8-hydroxy-2,7-naphthyridin-2-ium salts.

Expectant management of incomplete, spontaneous first-trimester miscarriage: outcome according to initial ultrasound criteria and value of follow-up visits

OBJECTIVES

To assess whether the presence of a gestational sac or the width of the endometrium, can be used to predict the outcome of expectant management for an incomplete, first-trimester miscarriage, and to determine an appropriate schedule for follow-up visits.

SUBJECTS

Consecutive women with a spontaneous miscarriage, who were attending an early pregnancy assessment unit.

METHODS

Transvaginal ultrasonography was used at the first visit to identify those women with an incomplete miscarriage--defined as the presence of heterogeneous products of conception within the uterus and distinguishable from a missed miscarriage or an anembryonic pregnancy. The sonographic end-points were the presence of a gestational sac or the thickness of the endometrium. All subjects were offered the choice of surgical evacuation of the uterus under general anesthesia or expectant management with a follow-up visit within a few days of the cessation of transvaginal bleeding, or weekly monitoring for 4-5 weeks. The main outcome measures were the number of women with a complete miscarriage (defined as the absence of transvaginal bleeding and an endometrial thickness of < 15 mm without surgical intervention) and the proportion of women completing their miscarriage within each week of management.

RESULTS

Of the 312 women who participated, 234 (75%) chose expectant management; of these 13 were lost to follow-up leaving data from 221 for analysis. Two-hundred and one (91%) completed their miscarriage without intervention; the mean time from diagnosis to completion was 9 (range, 1-32) days. By the end of week 2, 184 women (83%) had miscarried. There was no statistically significant relationship between the initial presence of a gestational sac or endometrial thickness, and the success rate of expectant management. The odds of a woman completing a miscarriage spontaneously were 1 : 1 for week 1, 2 : 1 for week 2, 1 : 2 for week 3, and 1 : 5 for week 4. Twenty women had surgical treatment (19 elective with no serious prior complications, one emergency who was admitted to the accident and emergency department on day 21 of management). There were eight elective operations during week 1, and 11 over the following 3 weeks.

CONCLUSIONS

Most women with an incomplete, spontaneous miscarriage chose expectant management and had a successful outcome. Neither the presence of a gestational sac, nor the endometrial thickness at diagnosis can be used to predict the likelihood of management failure. The current schedule of regular routine follow-up visits could be safely reduced to one or two fortnightly visits as appropriate, provided that patients have ready access to clinical advice by telephone.

The characterization of common ovarian cysts in premenopausal women

OBJECTIVES

The evaluation of the predictive value of transvaginal ultrasound in the assessment of benign adnexal pathology in premenopausal women, based on the recognition of characteristic morphologic patterns particular to endometriotic and dermoid ovarian cysts.

METHODS

This was a prospective study. All premenopausal women undergoing surgery for a suspected ovarian cyst underwent a transvaginal ultrasound examination in the week prior to surgery. Between June 1997 and January 2000, 132 women underwent surgery for a suspected ovarian endometrioma or dermoid cyst. The endpoints were either the direct visualization of the cyst wall and contents at surgery, or the histologic evaluation of removed tissues.

RESULTS

Of 83 suspected endometriomas (11 bilateral), 80 were confirmed at surgery and of 68 suspected benign cystic teratomas (eight bilateral), 66 were confirmed by histology. The positive predictive value of transvaginal ultrasonography for the diagnosis of endometrioma and dermoid cysts was 96.4% and 97.1%, respectively. The false positive rates were 3.8% and 3.0%, respectively. There were no malignancies in either group.

CONCLUSIONS

Based on the recognition of characteristic ultrasound patterns alone, the positive predictive value of transvaginal ultrasonography for the diagnosis of these common, benign cysts in premenopausal women is very high and can be used reliably to select women for appropriate surgery.