Low-dose dexamethasone as a treatment for women with heavy menstrual bleeding: protocol for response-adaptive randomised placebo-controlled dose-finding parallel group trial (DexFEM).

INTRODUCTION: Heavy menstrual bleeding (HMB) diminishes individual quality-of-life and poses substantial societal burden. In HMB endometrium, inactivation of cortisol (by enzyme 11ß hydroxysteroid dehydrogenase type 2 (11ßHSD2)), may cause local endometrial glucocorticoid deficiency and hence increased angiogenesis and impaired vasoconstriction. We propose that 'rescue' of luteal phase endometrial glucocorticoid deficiency could reduce menstrual bleeding. METHODS AND ANALYSIS: DexFEM is a double-blind response-adaptive parallel-group placebo-controlled trial in women with HMB (108 to be randomised), with active treatment the potent oral synthetic glucocorticoid dexamethasone, which is relatively resistant to 11ßHSD2 inactivation. Participants will be aged over 18 years, with mean measured menstrual blood loss (MBL) for two screening cycles ≥50 mL. The primary outcome is reduction in MBL from screening. Secondary end points are questionnaire assessments of treatment effect and acceptability. Treatment will be for 5 days in the mid-luteal phases of three treatment menstrual cycles. Six doses of low-dose dexamethasone (ranging from 0.2 to 0.9 mg twice daily) will be compared with placebo, to ascertain optimal dose, and whether this has advantage over placebo. Statistical efficiency is maximised by allowing randomisation probabilities to 'adapt' at five points during enrolment phase, based on the response data available so far, to favour doses expected to provide greatest additional information on the dose-response. Bayesian Normal Dynamic Linear Modelling, with baseline MBL included as covariate, will determine optimal dose (re reduction in MBL). Secondary end points will be analysed using generalised dynamic linear models. For each dose for all end points, a 95% credible interval will be calculated for effect versus placebo. ETHICS AND DISSEMINATION: Dexamethasone is widely used and hence well-characterised safety-wise. Ethical approval has been obtained from Scotland A Research Ethics Committee (12/SS/0147). Trial findings will be disseminated via open-access peer-reviewed publications, conferences, clinical networks, public lectures, and our websites. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov NCT01769820; EudractCT 2012-003405-98.

Physiological sex steroid replacement in premature ovarian failure: randomized crossover trial of effect on uterine volume, endometrial thickness and blood flow, compared with a standard regimen.

BACKGROUND: Premature ovarian failure (POF) is currently managed by non-physiological sex steroid regimens which are inadequate at optimizing uterine characteristics. Previous short-term studies have demonstrated some benefits of a sex steroid replacement (SSR) regimen devised to replicate the physiological cycle. This study aimed to directly compare the effects of longer-term administration of physiological SSR (pSSR) and standard SSR (sSSR) regimens on the uterine volume, blood flow and endometrial thickness (ET) in women with POF. METHODS: In a controlled crossover trial, 34 women with POF were randomized to receive 12 months of 4-week cycles of transdermal estradiol and vaginal progesterone (pSSR) followed by 12 months of 4-week cycles of oral ethinylestradiol and norethisterone (sSSR), or vice versa. Each treatment period was preceded by a 2-month washout period. At 0, 3, 6 and 12 months of each treatment period, transvaginal ultrasound examined the uterine volume and ET, as primary end-points, and uterine artery resistance (UARI) and pulsatility indices (UAPI), as secondary end-points. Serum estradiol, progesterone and gonadotrophins were also measured. RESULTS: Of the 29 women eligible for the uterine analysis, 17 completed the entire study protocol, but 25 women contributed data to statistical analysis of treatment effect. There was a greater estimated mean ET with the use of pSSR (4.8 mm) compared to that with standard therapy (3.0 mm), with an estimated difference of 1.8 mm [95% confidence interval (CI), 0.7 to 2.8, P=0.002]. The estimated mean uterine volume was also greater during physiological treatment (24.8 cm(3)) than during standard treatment (20.6 cm(3)), but the estimated difference of 4.2 cm(3) (95% CI -0.4 to 8.7) was not statitsically significant, P=0.070. The small differences between the two treatments in the mean UARI and mean UAPI were not statistically significant. The estimated treatment differences were fairly constant across the treatment periods, suggesting that prolonged treatment does not increase response. CONCLUSIONS: pSSR has a greater beneficial effect upon ET in women with POF in comparison with standard therapy. A similar trend was seen for uterine volume. Further studies are required to optimize treatment and to assess pregnancy rate and outcome. Trial Registration www.ClinicalTrials.gov, NCR00732693.

Tamoxifen resistance in early breast cancer: statistical modelling of tissue markers to improve risk prediction.

BACKGROUND: For over two decades, the Nottingham Prognostic Index (NPI) has been used in the United Kingdom to calculate risk scores and inform management about breast cancer patients. It is derived using just three clinical variables - nodal involvement, tumour size and grade. New scientific methods now make cost-effective measurement of many biological characteristics of tumour tissue from breast cancer biopsy samples possible. However, the number of potential explanatory variables to be considered presents a statistical challenge. The aim of this study was to investigate whether in ER+ tamoxifen-treated breast cancer patients, biological variables can add value to NPI predictors, to provide improved prognostic stratification in terms of overall recurrence-free survival (RFS) and also in terms of remaining recurrence free while on tamoxifen treatment (RFoT). A particular goal was to enable the discrimination of patients with a very low risk of recurrence. METHODS: Tissue samples of 401 cases were analysed by microarray technology, providing biomarker data for 72 variables in total, from AKT, BAD, HER, MTOR, PgR, MAPK and RAS families. Only biomarkers screened as potentially informative (i.e., exhibiting univariate association with recurrence) were offered to the multivariate model. The multiple imputation method was used to deal with missing values, and bootstrap sampling was used to assess internal validity and refine the model. RESULTS: Neither the RFS nor RFoT models derived included Grade, but both had better predictive and discrimination ability than NPI. A slight difference was observed between models in terms of biomarkers included, and, in particular, the RFoT model alone included HER2. The estimated 7-year RFS rates in the lowest-risk groups by RFS and RFoT models were 95 and 97%, respectively, whereas the corresponding rate for the lowest-risk group of NPI was 89%. CONCLUSION: The findings demonstrate considerable potential for improved prognostic modelling by incorporation of biological variables into risk prediction. In particular, the ability to identify a low-risk group with minimal risk of recurrence is likely to have clinical appeal. With larger data sets and longer follow-up, this modelling approach has the potential to enhance an understanding of the interplay of biological characteristics, treatment and cancer recurrence.

Economic evaluation of diagnosing and excluding ectopic pregnancy.

BACKGROUND: The diagnosis of ectopic pregnancy in women presenting in early pregnancy is often protracted, relying on costly investigations that are psychologically burdensome to the patient. The aim of this study was to evaluate the financial costs to the health services in Scotland of the current methods used to diagnose and exclude ectopic pregnancy, and compare these with that of a theoretical single diagnostic serum biomarker. METHODS: We conducted a retrospective cost-description analysis (with and without costs of diagnostic laparoscopy) of the health-care costs incurred by all patients presenting to a large Scottish teaching hospital between June and September 2006 with pain and bleeding in early pregnancy, where ectopic pregnancy was not excluded. Additionally, a cost minimization analysis was performed for the costs of current ectopic pregnancy investigations versus those of a theoretical single diagnostic serum biomarker. This included sensitivity analyses where the biomarker was priced at increasing values and assumed to have less than 100% diagnostic sensitivity and specificity. RESULTS: About 175 patients were eligible to be included in the analysis. Forty-seven per cent of patients required more than three visits to diagnose or exclude ectopic pregnancy. The total yearly cost for diagnosing and excluding ectopic pregnancy was 197K pound sterling for the hospital stated, and was estimated to be 1364K pound sterling for Scotland overall. Using a theoretical diagnostic serum biomarker we calculated that we could save health services up to 976K pound sterling (lowest saving 251K pound sterling after subanalysis) every year in Scotland. CONCLUSIONS: Ectopic pregnancy is expensive to diagnose and exclude, and the investigation process is often long and might involve significant psychological morbidity. The development of a single diagnostic serum biomarker would minimize this morbidity and lead to significant savings of up to 1 million pounds per year in Scotland.

Factors affecting adequacy of Pipelle and Tao Brush endometrial sampling.

OBJECTIVE: To compare factors influencing adequacy of endometrial samples obtained using two outpatient sampling devices--Pipelle and Tao Brush. DESIGN: Pragmatic unblinded trial with investigation schedule randomised separately within two groups according to endometrial cancer risk. SETTING: Gynaecology outpatient clinic of a large city hospital in Edinburgh, Scotland. POPULATION: All women referred to a gynaecology outpatient clinic during a 28-month period complaining of abnormal vaginal bleeding. METHODS: Women were assigned to two 'risk groups' for endometrial cancer ('high risk' for postmenopausal women and 'moderate risk' for premenopausal women aged over 40 years or with other risk factors). Women in each risk group had both types of biopsy and were randomised to two outpatient visualisations: hysteroscopy and/or transvaginal ultrasound scan. MAIN OUTCOME MEASURES: Completion of the investigation, adequacy of sample and acceptability of investigation to women. RESULTS: In 200 high-risk women, adequate samples were significantly more likely to be obtained by Tao Brush than Pipelle (P < 0.001). Nulliparity was strongly associated with failed insertion for both devices (P < 0.001). Inadequate samples were strongly associated with postmenopausal status only for Pipelle (P < 0.001), and among premenopausal women, for both samplers, with nulliparity (P < 0.001). A significantly greater proportion of women preferred the Tao Brush to the Pipelle endometrial sampler (P < 0.001). CONCLUSIONS: In postmenopausal women, Tao Brush sampling offers advantages over use of Pipelle, and the former should be considered as an alternative or additional sampling device in this group of women.

Piezoelectric sensors for dioxins: a biomimetic approach.

The aim of this work was to design a fast, cheap and easy to use analytical system for dioxins. Piezoelectric sensors coupled with the pentapeptides as biomimetic traps (the receptors), selective for the dioxins, were used for the realisation of this analytical system. A methodology to select specific receptors among all possible pentapeptides randomly generated was represented by the use of molecular modelling software. Three peptides called later on A, B and C (A:[N]Asn-Phe-Gln-Gly-Ile[C]; B:[N]Asn-Phe-Gln-Gly-Gln[C]; C:[N]Asn-Phe-Gln-Gly-Phe[C]), were selected and evaluated for their potential usage as artificial receptors in solid-gas analysis by using a quartz crystal microbalance (QCM) sensors array. The peptide sequences were functionalised by two terminal cysteine residues in order to achieve a covalent interaction with the QCM gold surface. A manganese-porphyrin complex and two other pentapeptides, a pentaglutamine (pentapeptide D) and a pentalysine (pentapeptide E), were used as negative control sensors. The QCM sensors (A, B and C) gave a good linearity against different sample concentrations of the 2,3,7,8-tetrachlorinated dibenzo-p-dioxin (TCDD) and a mixture of dioxins. In particular, the selectivity against 2,3,7,8-TCDD was nicely correlated to the estimated binding energy of the receptors calculated by computational modelling. The cross-reactivity of the system was quantified using commercial polychlorinated biphenyls (PCBs) mixtures (dioxin-like compounds).

Evaluation of abnormal uterine bleeding: comparison of three outpatient procedures within cohorts defined by age and menopausal status.

OBJECTIVES: To compare three outpatient methods of endometrial evaluation in terms of performance, patient acceptability and cost-effectiveness. DESIGN: Pragmatic unblinded trial randomised separately within three groups determined by risk of endometrial cancer. SETTING: The gynaecology outpatient clinic of a large city hospital in Edinburgh, Scotland. PARTICIPANTS: Women referred for investigation and management of abnormal bleeding between January 1999 and May 2001. INTERVENTIONS: Investigations were: blind biopsy alone, hysteroscopy with biopsy, ultrasound evaluation including transvaginal ultrasound, and, in the low-risk group, the option of no investigation. Within this design, two devices for obtaining endometrial biopsy were compared, the Pipelle sampler and the Tao brush. MAIN OUTCOME MEASURES: Successful (informative) completion of the investigation, acceptability of the investigation method to women, women's satisfaction with clinic care in the short term and at 10 months and 2 years of follow-up, and cost-effectiveness to the end of investigation. RESULTS: Minor adverse events (e.g. shock, patient distress) did not occur for ultrasound, but occurred in 16% and 10% of women for hysteroscopy and biopsy procedures respectively. Pipelle biopsy provided an acceptable endometrial sample for 79% of moderate-risk women, but only 43% of high-risk women. The Tao brush gave similar performance in moderate-risk women (77%), but was more successful than the Pipelle sampler in postmenopausal (high-risk) women (72%). There were significantly more successful visualizations for ultrasound than for hysteroscopy in both the low-risk and the moderate-risk group, and a similar but non-significant trend in the high-risk group. Ultrasound was significantly better than hysteroscopy at detecting fibroids, but hysteroscopy significantly better for polyps. At the 10-month follow-up, high-risk women who had been investigated by hysteroscopy (with biopsy) had the most positive views of their clinic experience, but this effect had largely disappeared by 24 months. In the moderate-risk group, the subgroup randomised to biopsy alone gave the most negative responses about their clinic experience and health now. Women wishing they had more investigation comprised 22% of moderate-risk women and 38% of low-risk women, but only 14% of postmenopausal women. At follow-up the moderate-risk women (with menstrual bleeding problems), compared with postmenopausal women, had much worse ratings for clinic experience and health now. Resource use tended to be higher in the moderate- and low-risk women. There was minimal difference in cost-effectiveness between investigation options in the high-risk group, with the option involving hysteroscopy being marginally better than ultrasound. The most cost-effective investigation in the moderate-risk group was biopsy alone and in the low-risk group ultrasound. CONCLUSIONS: Decision-making about investigation would be clarified if postmenopausal women were studied separately from premenopausal women with menstrual bleeding problems. For postmenopausal women exclusion of cancer is a main objective, so once investigation has been completed discharge follows, but in the woman with abnormal menstrual bleeding, even if serious pathology is excluded, the original presenting symptoms require management. About 60% of premenopausal women with abnormal bleeding reported that their symptoms were not 'much improved' at 10 months. Research is needed to understand this phenomenon, and to explore ways to integrate patient factors into optimising evaluation and treatment. The significance of benign pathologies in this group also requires clarification. Given the relatively small differences observed in cost-effectiveness, there is justification for allowing other issues (such as clinician preferences and women's perspectives) to influence decisions as to the investigation method. There is scope to make better use of patient factors to inform decisions as to the most efficient and acceptable method of investigation for an individual woman. Additional analyses, using data available as a result of this study, will contribute to this agenda.

Subclavian artery stenosis: prevalence, risk factors, and association with cardiovascular diseases.

OBJECTIVES: The objective was to assess the prevalence of subclavian artery stenosis (SS) in four cohorts (two free-living and two clinical populations) and determine both risk factors for this condition and the association with other cardiovascular conditions. BACKGROUND: The prevalence of SS in the general population is unknown, and its association with risk factors and other cardiovascular diseases is not well-established. METHODS: A total of 4,223 subjects (2,975 from two free-living cohorts and 1,248 from two clinical cohorts) were included in this cross-sectional analysis. Subclavian artery stenosis was defined as > or =15 mm Hg interarm pressure difference. RESULTS: The prevalence of SS was 1.9% in the free-living cohorts and 7.1% in the clinical cohorts; SS was significantly (p < 0.05) associated with past smoking (odds ratio [OR] = 1.80), current smoking (OR = 2.61), and higher levels of systolic blood pressure (OR = 1.90 per 20 mm Hg). Higher levels of high-density lipoprotein (HDL) cholesterol were inversely and significantly associated with SS (OR = 0.87 per 10 mg/dl). In regression analyses relating SS to other cardiovascular diseases, the only significant finding was with peripheral arterial disease (PAD) (OR = 5.11, p < 0.001). CONCLUSIONS: Significant SS is present in approximately 2% of the free-living population and 7% of the clinical population. Additionally, SS is correlated with current and past smoking histories, systolic blood pressure, HDL levels (inversely), and the presence of PAD. These findings suggest that bilateral brachial blood pressure measurements should routinely be performed in patients with an elevated risk profile, both to screen for SS, and to avoid missing a hypertension or PAD diagnosis because of unilateral pressure measurement in an obstructed arm.

Hysterectomy and ovarian function: levels of follicle stimulating hormone and incidence of menopausal symptoms are not affected by hysterectomy in women under age 45 years.

OBJECTIVE: To investigate levels of follicle stimulating hormone (FSH), as a measure of ovarian function and menopausal symptoms prior to and following hysterectomy in women under the age of 45 years. DESIGN: This was a prospective controlled study. SAMPLE: A total of 56 hysterectomy patients and 34 controls, up to the age of 42 years, were recruited. METHODS: Women undergoing hysterectomy were recruited prior to their operation and were matched, where possible, with controls for age, parity and smoking. Five blood samples were taken over 2 years, two before the operation (or at a 1-month interval in the control group) and then at 6 months, 1 year and 2 years. Questionnaires were completed at each sampling to assess symptoms associated with reduced estrogen secretion. RESULTS: No significant differences in FSH levels between patients and controls were found. Modest differences in FSH levels between different time-points were identified (p = 0.03), but this disappeared if age and smoking were included as covariates. For the questionnaire data, there were no significant differences between the two groups on the somatic and vasomotor scales, but for psychological symptoms the patients scored significantly higher than the controls (p = 0.007), particularly at the pre-operation time-point. CONCLUSION: The study found no evidence of compromise of ovarian function, as reflected in FSH levels, within 2 years of hysterectomy. Psychological symptoms were higher in women undergoing hysterectomy both before and after the operation.

Opportunistic screening for chlamydia infection in general practice: can we reach young women?

OBJECTIVE: To study opportunistic screening in primary care, in such a way that would include teenage women. Setting-Screening for chlamydia infection was offered opportunistically in eight general practices in Edinburgh to women aged < or = 35 years attending for cervical smear, and women aged < or = 20 years attending for contraception. The numbers of women eligible to be offered screening were 901 in the cervical smear group, and 595 in the contraception group. RESULTS: Effective screening rate (offered test, consented, and urine sample returned) was 30% for the cervical smear group compared with 23% for the contraception group. Among those tested, chlamydia prevalence was strongly associated with young age, ranging from 11.8% in those <18 years, to 0% in those >25 years. Number of sexual partners in past year did not improve prediction of infection. CONCLUSION: These findings raise concerns regarding the feasibility of opportunistic screening in general practice, particularly for those with highest prevalence of chlamydia--teenage women.

Apoptotic and proliferative activity in the neoplastic progression of Barrett's oesophagus: a comparative study.

The balance between proliferation and apoptosis within a tissue is important in controlling its overall growth. When either or both are altered, uncontrolled cell proliferation can contribute to cancer. The aim of this study was to investigate apoptosis and proliferation in the progression from Barrett's oesophagus to adenocarcinoma. Fifty-one paraffin sections of Barrett's mucosa with both intestinal and gastric-type Barrett's mucosa, dysplasia, and adenocarcinoma, from 28 patients, were examined for apoptosis using haematoxylin and eosin (H&E)-stained sections counterstained immunohistochemically with CD45 to distinguish leucocytes from apoptotic bodies. Proliferation was detected by immunohistochemistry using the MIB-1 (Ki-67) antibody. There was an increase in proliferation in dysplastic and carcinomatous tissue compared with metaplastic tissue (p=0.0001). In dysplasia, proliferation was distributed throughout the basal-luminal axis, whereas in metaplasia, cell division was compartmentalized to the lower crypt (p<0.001). Conversely, there was a decrease in apoptosis in the upper crypt and luminal surface in dysplasia and adenocarcinoma compared with metaplasia (p<0.0008). There was a significant increase in apoptotic activity in intestinal-type Barrett's mucosa compared with gastric-type. There was a highly significant increase in the glandular proliferation to apoptosis ratio (GPAR) in the progression of metaplasia to dysplasia to adenocarcinoma (p=0.001). The shift in the GPAR in the progression of neoplastic change suggests that it may be a useful and sensitive marker of neoplastic change in Barrett's oesophagus, especially if the assessment of both apoptotic and proliferative activity in the mucosa can be made easier by more sophisticated technical methods.

Altered cadherin and catenin complexes in the Barrett's esophagus-dysplasia-adenocarcinoma sequence: correlation with disease progression and dedifferentiation.

The maintenance of adult tissue architecture is largely dependent on the function of cadherins. E-cadherin is expressed in most epithelia, although it may be co-expressed with P-cadherin in basal layers of stratified epithelia. Adhesive function of cadherins relies on interactions with catenins. Many reports have characterized reduced expression of cadherins and catenins in tumors, including those of the gastrointestinal tract. This study aimed to characterize expression of E- and P-cadherins, and the catenins, in the progression of Barrett's esophagus to adenocarcinoma. Immunohistochemical analysis and Western blotting were performed on paraffin-embedded and fresh-frozen tissue using antisera to the selected cadherins and catenins. The results of this study have shown inappropriate expression of cadherins and catenins in neoplastic Barrett's mucosa. There was a significant reduction of E-cadherin expression as the Barrett's metaplasia-dysplasia-adenocarcinoma sequence progressed (P < 0.01). In contrast, P-cadherin, expressed in basal layers of squamous esophagus, was usually absent from Barrett's and dysplasia but was expressed in 17 of 24 carcinomas, especially at the advancing tumor edge. Reduced expression of catenins was also seen, but in some specimens, immunoreactivity was observed in neoplastic nuclei, suggesting mediation of a nuclear function such as transcriptional regulation.

Non-peptidic inhibitors of human leukocyte elastase. 1. The design and synthesis of pyridone-containing inhibitors.

Human leukocyte elastase (HLE) is a serine protease produced by neutrophils that has been implicated in diseases such as emphysema and cystic fibrosis. An HLE inhibitor may have therapeutic value in these diseases. An active site model of HLE bound to a tripeptidic trifluoromethyl ketone (TFMK) inhibitor, 2, was created from X-ray structures of HLE and porcine pancreatic elastase. Analysis of the model indicated a preferred binding conformation for the tripeptide and potentially important interactions between it and the enzyme. This information was used to aid in the design of a series of novel, pyridone-containing, non-peptidic HLE inhibitors such as 2-[3-[[(benzyloxy)carbonyl]amino]-2-oxo- 1,2-dihydro-1-pyridyl]-N-(3,3,3-trifluoro-1-isopropyl-2-oxopropyl)ace tam ide (5b) (Ki = 280 +/- 78 nM). Inspection of the active site model suggested that a benzyl substituent at the 5-position of the pyridone ring might improve potency by forming a lipophilic interaction with the enzyme S2 pocket. Synthesis and biological evaluation of a series of 5-benzylpyridone TFMKs provided evidence for this proposition. Further analysis of the model indicated that substitution on the 3-amino group of the pyridone ring with a hydrogen bond acceptor could potentially lead to interactions with the NH atoms of glycine-218 and/or -219. The oxalate derivative 2-[5-benzyl- 3-(carboxycarbonyl)-2-oxo-1,2-dihydro-1-pyridyl]-N-(3,3,3-trifl uor o-1- isopropyl-2-oxopropyl)acetamide (5v) was synthesized and found to have a Ki of 48 +/- 9 nM. Unfortunately, none of the compounds tested was active in an in vivo model of HLE-induced lung injury when dosed orally.

Posttranslational modifications in microcin B17 define an additional class of DNA gyrase inhibitor.

Drugs that inhibit the activity of DNA gyrase fall almost exclusively into two structural classes, the quinolones and the coumarins. A third class of DNA gyrase inhibitor is defined by the ribosomally synthesized peptide antibiotic microcin B17 (MccB17). MccB17 contains 43 amino acid residues, but 14 of these are posttranslationally modified. Here we describe the characterization of the structure of these modifications. We propose that four cysteine and four serine side chains undergo condensation with the carbonyl group of the preceding residue, followed by alpha/beta dehydrogenation to yield four thiazole and four oxazole rings, respectively. The three proteins implicated in catalyzing these modifications (McbBCD) would constitute the only thiazole/oxazole biosynthetic enzymes identified. These results open up possibilities for the design of DNA gyrase inhibitors and add to the repertoire of posttranslational modifications with potential for protein engineering. Escherichia coli sbmA mutants, which lack the inner membrane protein (SbmA) involved in MccB17 uptake, were found to be resistant to bleomycin. Bleomycin is structurally unrelated to MccB17 except for the fact that it contains two thiazole rings. This suggests that thiazole rings are part of the MccB17 structure recognized by SbmA. This observation and the finding that SbmA homologs are widely conserved and can play developmental roles [Glazebrook, J., Ichige, A. & Walker, G. C. (1993) Genes Dev. 7, 1485-1497] suggest that thiazole- and oxazole-containing compounds may serve as signaling molecules for a wide variety of bacteria in diverse environments, including pathogen interactions with plant and animal hosts.

Quinoline antifolate thymidylate synthase inhibitors: variation of the C2- and C4-substituents.

Modifications to the bicyclic ring system of the potent thymidylate synthase (TS) inhibitor N-[4-[N-[(2-amino-3,4-dihydro-4-oxo-6- quinazolinyl)methyl]-N-prop-2-ynylamino]benzoyl]-L-glutamic acid (1, CB3717) have led to the synthesis of a series of quinoline antifolates bearing a variety of substituents at the C2 and C4 positions. In general the synthetic route involved the coupling of the appropriate diethyl N-[4-(prop-2-ynylamino)benzoyl]-L-glutamate with a disubstituted 6-(bromomethyl)quinoline followed by deprotection using mild alkali. The compounds were tested as inhibitors of partially purified L1210 TS. As a measure of cytotoxicity, the compounds were tested for their inhibition of the growth of L1210 cells in culture. Good enzyme inhibition and cytotoxicity were found for compounds containing chloro, amino, or methyl substituents at the C2 position with chloro or bromo substituents at C4. The effect on enzyme inhibition of varying the N10 substituent of 2h was similar to that observed in the quinazolinone-containing antifolates, indicating that the quinoline compounds may be interacting with the enzyme in a similar way to the quinazolinones. Also, the introduction of a 2'-fluoro substituent into the benzoyl ring of several of the quinoline antifolates led to an increase in both TS inhibition and the inhibition of L1210 cell growth. These data demonstrate that the N3-H of the pyrimidine ring of the quinazolinone antifolates is not required for binding to TS if appropriate substituents are placed at the C2 and C4 positions of the bicyclic ring system.

Paternally inherited effects of gamma radiation on mouse preimplantation development detected by the chimera assay.

It has previously been shown that type B spermatogonia in male mice treated with 0.05 Gy of X rays undergo an alteration expressed by progeny embryos as a cellular proliferation disadvantage in a chimera assay. We wished to obtain information on the assay's detection limit to ionizing radiation and on the radiosensitive target in male germ cells. Male mice were briefly irradiated with 137Cs gamma rays at nominal absorbed doses of 0.0, 0.0015, 0.005, 0.010, or 0.05 Gy and then mated for the next 8 weeks to untreated females. Four-cell embryos from treated males (experimental embryos) were paired with FITC-labeled embryos from untreated males (control embryos) to form aggregation chimeras. The chimeras were cultured for 30-40 h and examined under phase-contrast and UV illumination for the number of unlabeled cells (from the experimental embryo) and total chimera cell number, which were then expressed as "proliferation ratios" (No. unlabeled cells/total chimera cell No.). Significant decreases in proliferation ratios were observed at postirradiation weeks 4, 6, and 7 for the 0.01-Gy dose group and at weeks 5-6 for the 0.05-Gy dose group. In addition, significantly lower ratios were observed with early and mid four-cell embryos, but not with late four-cell embryos. These results suggest that mouse male germ cells express a radiosensitive target(s) whose detection limit by the assay lies at an absorbed dose between 0.005 and 0.010 Gy for brief gamma irradiation and whose effect on embryonic cell proliferation might decay by the second cleavage.

Quinazoline antifolates inhibiting thymidylate synthase: 4-thio-substituted analogues.

We report the synthesis of four new 4-thio-5,8-dideazafolic acid analogues and a 4-(methylthio) analogue structurally related to the thymidylate synthase (TS) inhibitor N10-propargyl-5,8-dideazafolic acid. Three N10-propargyl-4-thio-5,8-dideazafolic acid analogues had C2 amino, hydrogen, and methyl substituents. A 4-thio and a 4-(methylthio) compound each with hydrogen at C2 and ethyl at N10 were also synthesized. In general, the synthetic route involved thionation of the appropriate 4-oxoquinazoline; the sulfur thus introduced was then protected by methylation. Further protection with a pivaloyl group was required for the quinazoline bearing a 2-amino substituent. The protected quinazolines were treated with N-bromosuccinimide and the resulting 6-(bromomethyl) compounds were then coupled to the appropriate N-monoalkylated diethyl N-(4-aminobenzoyl)-L-glutamate in N,N-dimethylacetamide with calcium carbonate as base. The 4-thio-5,8-dideazafolic acids were obtained by removal of the methylthio group with sodium hydrosulfide, followed by deprotection of the carboxyl groups with cold dilute alkali. For the compound containing a pivaloyl protecting group, hot dilute alkali was used. To obtain the 5,8-dideazafolic acid containing a 4-(methylthio) substituent, the corresponding diester was treated with lithium hydroxide which selectively deprotected the carboxyl groups. The five compounds were tested as inhibitors of L1210 TS. It was found that replacement of the 4-oxygen of the quinazoline moiety by sulfur did not alter the TS inhibition. However, the introduction of a methylthio substituent at position 4 severely impaired TS inhibition. All 4-thio compounds were less cytotoxic to L1210 cells in culture than their 4-oxo counterparts.

The use of an LHRH agonist, buserelin, in the long-term management of premenstrual syndromes.

Buserelin, an LHRH agonist, was given by nasal spray to 20 women with premenstrual syndrome. In 10 women benefits were such that they continued treatment for periods varying from 5 to 15 months. There were significant improvements in mood and physical symptoms, and side-effects such as hot flushes were mild. The remaining 10 women were all made worse by the spray and stopped it within 2 months. Ovulation was blocked in all women though six showed evidence of ovulation during the first treatment month, and two women later in treatment. Of the long-term group, six eventually became amenorrhoeic, and four continued to menstruate. There was a significant improvement in symptoms during treatment in the long-term group. Physical symptoms continued to be worse before any menstrual bleeding. Mood change lost its relationship to menstruation. The adverse effects in the short-term group were sometimes severe and it is necessary to identify the characteristics of the woman who are likely to show such reactions before recommending this treatment for more general use.