The Effects of p-nonylphenol on the Myometrial Contractile Activity

We aimed to investigate the effects and mechanisms of action of p-nonylphenol(p-NP) on uterine contractility in rats. The uterine tissues of female Sprague Dawley rats in diestrus were bathed in isolated organ bath. The effects of vehicle alone (0.1% ethanol), the positive control 17-β-E2 (10(-5) M) and p-NP (10(-9) M, 10(-8) M, 10(-7) M, 10(-6) M) on spontaneous and KCl-induced uterine contractility of rats were studied. Also, the effects of p-NP in combination with actinomycin D (10(-5) M) (gene transcription inhibitor), cycloheximide (10(-4) M) (protein synthesis inhibitor), fulvestrant (10(-6) M) (pure estrogen receptor antagonist), 2-hydroxy-5-nonanoylbenzamide (10(-3) M) (compound 1b, anti-uterotrophic compound) on spontaneous uterine contractions, and with propranolol (20 µM) (β-adrenoceptor antagonist) and noradrenaline (5 µM) on KCl (40 mM) induced contractions were investigated. p-NP exhibited a concentration-dependent inhibition on spontaneous uterine contractions. There was no significant difference between the highest p-NP concentration (10(-6) M) and the positive control 17-β-E2 in terms of % inhibition (p>0.05). The inhibitory effect of p-NP (10(-6) M) on spontaneous contractions was blocked by actinomycin D (p<0.001), cycloheximide (p<0.001), fulvestrant (p<0.001) and compound 1b (p<0.001). 17-β-E2 (10(-5) M) exerted a higher inhibition % on KCl induced contractions than p-NP (10(-6) M). The relaxant effect of p-NP on KCl-induced uterine contractions was inhibited by noradrenaline (p<0.05) but not by propranolol (p>0.05). We suggest that p-NP inhibited uterine contractions similar as 17-β-E2 and genomic pathways are involved and β-adrenoceptors might modulate the activity of p-NP. In addition, compound 1b showed an uterotonic activity and reversed the effect of p-NP.

Microwave-assisted synthesis of 1,3-benzothiazol-2(3H)-one derivatives and analysis of their antinociceptive activity

A rapid and efficient method was developed for synthesis of 6-acyl-1,3-benzothiazol-2(3H)-one derivatives under microwave irradiation (MWI) conditions. The reaction times were shortened compared to conventional heating. Additionally, we synthesized acetic acid and acetamide derivatives of 1,3-benzothiazol-2(3H)-one, 6-acyl-1,3-benzothiazol-2(3H)-one, 5-chloro-1,3-benzothiazol-2(3H)-one and 6-acyl-5-chloro-1,3-benzothiazol-2(3H)-one with the microwave-assisted method and analyzed their antinociceptive activity with the tail flick, tail clip, hot plate and writhing tests. Among the synthesized compounds, 3-[2-(4-ethylpiperazin-1-yl)-2-oxoethyl]-1,3-benzothiazol-2(3H)-one (6a), 5-chloro-3-{2-oxo-2-[4-(propan-2-yl) piperazin-1-yl]ethyl}-1,3-benzothiazol-2(3H)-one (7e) and 3-[2-(4-butylpiperazin-1-yl)-2-oxoethyl]-5-chloro-1,3-benzothiazol-2(3H)-one (8e) showed significant antinociceptive activity in the tail clip, tail flick, hot plate and writhing tests. Supporting Information available online at http://www.thieme-connect.de/ejournals/toc/amf.

Self expandable polytetrafluoroethylene stent for carotid blowout syndrome

Carotid blowout syndrome (CBS) is an emergency complication in patients undergoing treatment for head and neck cancers. The classical management of CBS is the ligation of the common carotid artery, because suturing is not be possible due to infection and necrosis of the field. In this case report, we present a patient with CBS, in whom we applied a self-expandable polytetrafluoroethylene (PTFE) stent and observed no morbidity. Endovascular stent is a life-saving technique with minimum morbidity that preserves blood flow to the brain. We believe that this method is preferable to ligation of the artery in CBS.

The clinical effectiveness and cost-effectiveness of central venous catheters treated with anti-infective agents in preventing bloodstream infections: a systematic review and economic evaluation

OBJECTIVES

To assess the clinical effectiveness and cost-effectiveness of central venous catheters (CVCs) treated with anti-infective agents in preventing catheter-related bloodstream infection (CRBSI).

DATA SOURCES

Major electronic databases were searched from 1985 to August 2005.

REVIEW METHODS

The systematic clinical and economic reviews were conducted according to accepted procedures. Only full economic evaluations (synthesis of costs and benefits) comparing the use of anti-infective central venous catheters (AI-CVCs) with untreated CVCs or other treated catheters were selected for inclusion in the economic review.

RESULTS

A total of 32 trials met the clinical inclusion criteria. Seven different types of AI-CVC were identified, with the most frequently tested being chlorhexidine and silver sulfadiazine (CHSS) (externally treated), CHSS (externally and internally treated) and minocycline rifampicin (internally and externally treated). In general, the trials were of a poor quality in terms of reported methodology, microbiological relevance and control of confounding variables. The pooled result suggests a statistically significant advantage for AI-CVCs in comparison to standard catheters in reducing CRBSI [odds ratio (OR) 0.45, 95% confidence interval (CI) 0.34 to 0.60, 24 studies, I-squared = 0%, fixed effects]. Analysis by subgroups of catheters demonstrates that antibiotic-treated catheters and catheters treated internally and externally decrease CRBSI rates significantly (OR 0.26, 95% CI 0.15 to 0.46, six studies, I-squared = 0%, fixed effects, and OR 0.43, 95% CI 0.26 to 0.70, nine studies, I-squared = 0%, fixed effects, respectively). Catheters treated only externally demonstrate a wider CI and non-significant effect (OR 0.67, 95% CI 0.43 to 1.06, nine studies, I-squared = 0%, fixed effects). A treatment effect was also found for trials with an average duration of between 5 and 12 days, and for the one study with a mean duration of over 20 days. There was a statistically significant treatment effect for both femoral and jugular insertion sites and for those studies reporting a mix of insertion sites. The treatment effect was not observed in trials using exclusively subclavian insertion sites. Of the four trials that compared treated catheters, one reported a benefit of antibiotic-treated catheters over catheters treated externally with CHSS. All three sensitivity analyses testing for study design differences reported a statistically significant treatment effect. The review was limited owing to the quality of the trials included, marked differences in the definitions and methods of diagnosis of CRBSI, and inconsistent reporting of risk factors and patient population factors. Furthermore, two-thirds of trials were commercially funded. The economic performance (cost-effectiveness and potential cost-savings) of using AI-CVCs to reduce the number of CRBSIs in patients requiring a CVC was also reviewed. Results show that the use of AI-CVCs instead of standard CVCs can lead to a reduction in CRBSIs and decreased medical costs. To complement the reviews, a basic decision-analytic model was constructed to explore a range of possible scenarios for the NHS in England and Wales. Results show that for every patient who receives an AI-CVC there is an estimated cost-saving of 138.20 pounds. The multivariate sensitivity analyses estimate potentially large cost-savings, depending on the size of the population, under a wide range of cost and clinical assumptions. However, those considering the purchase of AI-CVCs should ensure that their patient populations and the important characteristics of local clinical practice are indeed similar to those described in this economic evaluation.

CONCLUSIONS

Overall, AI-CVCs are clinically effective and relatively inexpensive and therefore their integration into clinical practice can be justified. However, the use of these anti-infective catheters without the appropriate use of other practical care initiatives will have only a limited success on the prevention of CRBSIs. Comparative trials are required to determine which, if any, of the treated catheters is the most effective. Pragmatic research related to the effectiveness of bundles of care that may reduce rates of CRBSI is also warranted.

Drug-eluting stents: a systematic review and economic evaluation

OBJECTIVES

To assess the effectiveness and cost-effectiveness of the use of drug-eluting coronary artery stents in percutaneous coronary intervention (PCI) in patients with coronary artery disease.

DATA SOURCES

Bibliographic databases, including MEDLINE, EMBASE and the Cochrane Library, were searched from December 2002 to August 2005. Hand-searching was also done.

REVIEW METHODS

A systematic literature review of effectiveness was conducted focusing primarily on randomised controlled trials (RCTs). Full economic evaluations that compared two or more options and considered both costs and consequences were eligible for inclusion in the economics review. A critique of manufacturer submissions to the National Institute for Health and Clinical Excellence and an economic evaluation in the form of cost-utility analysis were also carried out.

RESULTS

In the 17 RCTs of drug-eluting stents (DES) versus bare metal stents (BMS), no statistically significant differences in mortality or myocardial infarction (MI) were identified up to 3 years. Significant reductions in repeat revascularisations were determined for DES compared with BMS [for example, at 1 year: target lesion revascularisation (TLR) relative risk 0.24; 95% confidence interval (CI) 0.19 to 0.31; and target vessel revascularisation (TVR) relative risk 0.43; 95% CI 0.33 to 0.55]. This estimated benefit appears to be stable from 1 to 3 years. Binary restenosis and late luminal loss also favoured DES. In the eight RCTs of DES versus DES, no statistically significant differences in mortality or MI were detected between DES designs. In meta-analyses of TLR, TVR and composite event rate, marginal improvement in efficacy of Cypher trade mark over Taxus trade mark was observed. These results await confirmation beyond 1 year and differences in study design may have influenced reporting of outcomes. Ten full economic evaluations were included in the review and the balance of evidence indicated that DES are more cost-effective in higher risk patients. The review of submitted models confirmed the view that DES may be cost-effective only under very limited circumstances when realistic assumptions and data values were used. In the cost-utility analysis of DES versus BMS, the use of DES appears to reduce the rate of repeat revascularisations; benefit estimates used in the economic assessment are defined as 'broad' (i.e. cases involving any TLR/TVR irrespective of any other lesions/vessels undergoing revascularisation) and 'narrow' (i.e. cases involving TLR/TVR only). The incremental benefit to the patient is therefore described as the loss of quality-adjusted life-years (QALYs) avoided by not having to undergo a repeat revascularisation. Univariate sensitivity analysis and extreme values analysis indicate that the price premium, numbers of stents used in the index procedure and absolute risk reduction in repeat interventions most significantly influence the cost-effectiveness ratios. Sensitivity analyses also permit a range of values for efficacy and effectiveness to be considered for individual designs of DES. The cost-effectiveness results reveal that, all patients considered together, the calculated cost per QALY ratios are high (183,000-562,000 pounds) and outside the normal range of acceptability. Cost-effectiveness is only achieved for those non-elective patients who have undergone a previous coronary artery bypass graft and have small vessels. 'Real-world' data show that patient numbers in this latter group are very small (one in 3100 of all patients treated with PCI).

CONCLUSIONS

The conclusions of the assessment are that the use of DES would be best targeted at the subgroups of patients with the highest risks of requiring reintervention, and could be considered cost-effective in only a small percentage of such patents. This is similar to the conclusion of our previous assessment. Trials of DES compared with new generation BMS and with DES would be useful, as would further evaluation of newer BMS in combination with drug administration.

Newer hypnotic drugs for the short-term management of insomnia: a systematic review and economic evaluation

OBJECTIVES

To assess the clinical and cost-effectiveness of zaleplon, zolpidem and zopiclone (Z-drugs) compared with benzodiazepines.

DATA SOURCES

Electronic databases, reference lists of retrieved articles and pharmaceutical company submissions.

REVIEW METHODS

Randomised controlled trials (RCTs) that compared either benzodiazepines to the Z-drugs or any two of the non-benzodiazepine drugs in patients with insomnia were included in the review. Data on the following outcome measures were considered: sleep onset latency, total sleep duration, number of awakenings, quality of sleep, adverse effects and rebound insomnia. A search was also undertaken for any study designs that evaluated issues related to adverse events (e.g. dependency and withdrawal symptoms). Full economic evaluations that compared two or more options and considered both costs and consequences including cost-effectiveness, cost-utility analysis or cost-benefit analysis undertaken in the context of high-quality RCTs were considered for inclusion in the review.

RESULTS

Twenty-four studies, involving a total study population of 3909 patients, met the inclusion criteria. These included 17 studies comparing a Z-drug with a benzodiazepine and seven comparing a Z-drug with another Z-drug. The diversity of possible comparisons and the range of outcome measures in the review may be confusing. Outcomes were rarely standardised and, even when reported, differed in interpretation. In addition, variations in assessment and variety in the level of information provided make study comparisons difficult. As a result, meta-analysis has been possible on only a small number of outcomes. However, some broad conclusions might be reached based on the limited data provided. The existing published economic literature in this area is very limited. No relevant economic evaluations were identified for inclusion in the review. The industry submissions did not include detailed evidence of cost-effectiveness. Given the lack of robust clinical evidence, no economic model describing the costs and benefits of the newer hypnotic drugs for insomnia was developed. The systematic review provided in this report suggests that an agnostic approach to cost-effectiveness is required at this stage. In the short-term, no systematic evidence is available concerning significant outcome variations between either the different classes of drugs or between individual drugs within each class. Within this short-term horizon, the one element that does vary significantly is the acquisition cost of the individual drugs.

CONCLUSIONS

The short-acting drugs seem equally effective and safe with minor differences that may lead a prescriber to favour one over another in different patients. There is no evidence that one is more cost-effective than any other. Analysis of the additional costs to the NHS, depending on the rate of change from benzodiazepine prescriptions to Z-drug prescriptions, at current levels of hypnotic prescribing, range from GBP2 million to GBP17 million per year. There are clear research needs in this area; in particular, none of the existing trials adequately compare these medications. It is suggested that further consideration should be given to a formal trial to allow head-to-head comparison of some of the key drugs in a double-blind RCT lasting at least 2 weeks, and of sufficient size to draw reasonable conclusions. We would also recommend that any such trial should include a placebo arm. It should also collect good-quality data around sleep outcomes and in particular quality of life and daytime drowsiness. We do not believe that any formal study of risk of dependency is feasible at present. Finally, the management of long-term insomnia is suggested for further investigation: considering the frequency of this symptom and its recurring course, the short-term trial of medication and lack of long-term follow-up undermine attempts to develop evidence-based guidelines for the use of hypnotics in this condition, or indeed for its whole management.

Coronary artery stents: a rapid systematic review and economic evaluation

OBJECTIVES

To assess the effectiveness and cost-effectiveness of the use of coronary artery stents in patients with coronary heart disease (CHD).

DATA SOURCES

Electronic databases.

REVIEW METHODS

The review was conducted following accepted guidelines for conducting systematic reviews. Randomised controlled trials that include comparisons of percutaneous transluminal coronary angioplasty (PTCA) versus PTCA with stent, stent versus coronary artery bypass graft (CABG), and drug-eluting stents (DES) versus non-DES in patients with CAD in native or graft vessels and those with stable angina or acute coronary syndrome (ACS) and unstable angina were also included. Data on the following outcome measures were included in the review: combined event rate or event-free survival, death, acute myocardial infarction, target vessel revascularisation, repeat treatment (PTCA, stent or CABG) and binary restenosis. An economic model was developed based on extrapolation of trends in mortality and revascularisation from clinical trials data to a 5-year time horizon.

RESULTS

The inclusion criteria were fulfilled by 50 studies comparing the use of stents with PTCA, six comparing stents with CABG and 12 comparing DES eluting stents with non-DES. No studies were identified that compared DES with PTCA or DES with CABG. Existing quality of life data suggest that revascularisation procedures reduce the patient's quality of life for a short period only. Stents were found to be more effective than PTCA in preventing adverse events and revascularisations. In multiple-vessel disease there was no evidence of a difference in mortality (at 1 year) between patients treated surgically and those receiving a stent. Patients treated surgically required fewer revascularisations. There is no evidence of a difference in mortality between patients receiving DES and those treated with bare metal stents at 1 year. A reduction in event rate at 9 and 12 months was found in patients treated with DES. This event rate is primarily made up of increased revascularisation rates in patients treated with bare metal stents. Two-year outcome data from one study indicate that this benefit of DES continues over the longer term. The economic model proved sufficient to indicate long-term trends in cost-effectiveness. CABG was found initially to be more expensive than bare metal stenting in multivessel disease and may have higher immediate risks, but over time the cost differential is reduced and long-term outcomes favour CABG over stenting. A similar situation was found for DES versus CABG in multiple-vessel disease. However, DES may not generally be considered a cost-effective alternative to bare metal stenting in single-vessel disease by policy makers as substantially higher costs are involved with a very small outcome benefit.

CONCLUSIONS

DES might be considered cost-effective if the additional cost (compared with ordinary stents) was substantially reduced, the outcome benefits from the use of DES were much improved, and/or its use were targeted on the subgroups of patients with the highest risks of requiring reintervention. Long-term clinical studies are needed that focus on significant outcomes such as mortality. Further research should consider: the differences among plain stents; head-to-head comparisons within DES, CABG compared with DES; and the evaluation of newer non-DES against DES. Evaluation of the effects of revascularisation procedures and especially repeat revascularisation procedures on the patient's quality of life would also be useful, as would the development and testing of risk assessment tools to identify patients likely to need further revascularisations.

Influence of noise exposure on antioxidant system and TEOAEs in rabbits

Noise exposure may cause hearing loss. The precise mechanism leading to cochlear damage in aco trauma is not known. Eight rabbits were used in this study. Transient evoked otoacoustic emissions (TEOAEs) were recorded in all animals and blood malondialdehyde (MDA) and glutathione (GSH) levels were determined. All rabbits were then exposed to 100 dB SPL broadband noise for 1 h. TEOAEs were recorded again and blood MDA and GSH levels determined following noise exposure. The reproducibility scores of the TEOAE measurements were found to be significantly lower (P < 0.01), whereas the amplitudes and signal-to-noise values of emissions decreased (P > 0.01) in rabbits exposed to noise. The TEOAE energies were poor at 4 kHz. During this threshold shift, GSH blood levels decreased and MDA levels increased,indicating that there is a close relationship between noise-induced hearing loss and the antioxidant system. These findings indicate that TEOAE recording is an excellent test for detecting effects of noise on hearing.