Shock-Augmented Ignition Approach to Laser Inertial Fusion

Shock ignition enables high gain at low implosion velocity, reducing ablative Rayleigh-Taylor instability growth, which can degrade conventional direct drive. With this method, driving a strong shock requires high laser power and intensity, resulting in inefficiencies in the drive and the generation of hot electrons that can preheat the fuel. A new "shock-augmented ignition" pulse shape is described that, by preconditioning the ablation plasma before launching a strong shock, enables the shock ignition of thermonuclear fuel, but importantly, with substantially reduced laser power and intensity requirements. The reduced intensity requirement with respect to shock ignition limits laser-plasma instabilities, such as stimulated Raman and Brillouin scatter, reducing the risk of hot-electron preheat and restoring the laser coupling advantages of conventional direct drive. Simulations indicate that, due to the reduced power requirements, high gain (∼100) ignition of large-scale direct drive implosions (outer radius ∼1750  μm, deuterium-tritium ice thickness ∼165  μm) may be possible within the power and energy limits of existing facilities such as the National Ignition Facility. Moreover, this concept extends to indirect drive implosions, which exhibit substantial yield increases at reduced implosion velocity. Shock-augmented ignition expands the viable design space of laser inertial fusion.

Shock Ignition Laser-Plasma Interactions in Ignition-Scale Plasmas

We use a subignition scale laser, the 30 kJ Omega, and a novel shallow-cone target to study laser-plasma interactions at the ablation-plasma density scale lengths and laser intensities anticipated for direct drive shock-ignition implosions at National Ignition Facility scale. Our results show that, under these conditions, the dominant instability is convective stimulated Raman scatter with experimental evidence of two plasmon decay (TPD) only when the density scale length is reduced. Particle-in-cell simulations indicate this is due to TPD being shifted to lower densities, removing the experimental back-scatter signature and reducing the hot-electron temperature. The experimental laser energy-coupling to hot electrons was found to be 1%-2.5%, with electron temperatures between 35 and 45 keV. Radiation-hydrodynamics simulations employing these hot-electron characteristics indicate that they should not preheat the fuel in MJ-scale shock ignition experiments.

900 An Audit of Effectiveness of Inhaled Methoxyflurane (Penthrox) Use for Reduction of Shoulder Dislocation

Introduction

Shoulder dislocation is a painful injury best treated by early closed reduction. Patients often require intravenous sedation, with airway monitoring in a safe setting. We implemented methoxyflurane inhalational analgesia (Penthrox) to aid shoulder dislocation reduction without the need for sedation and evaluated the effectiveness and adverse events.

Method

Patients presenting to the minor injury’s unit at Wrexham Maelor Hospital between 01/04/2020 and 26/05/2020 with only shoulder dislocation were included. Patients had Penthrox and underwent closed reduction. Pre and post reduction shoulder radiographs were reviewed to determine reduction success and time between radiographs was evaluated. Adverse events were recorded. Reduction success and times between radiographs were compared to a consecutive retrospective cohort of patients who underwent closed shoulder dislocation reduction with sedation before implementing Penthrox.

Results

22 patients were included. Mean patient age was 44.6 years. Majority were male (72%). Penthrox was used in 11 patients. All patients had their shoulder dislocation reduced successfully. Mean time between reduction radiographs for the Penthrox group was 40.8 min (95%CI 27.4 to 54.3). This was shorter than the intravenous sedation group mean 157.7 minutes (95%CI 92.3 to 223.2, p = 0.0026). No documented adverse events with Penthrox.

Conclusions

Simple shoulder dislocations can be reduced safely, quickly, and effectively using Penthrox.

Status of the UCN experiment

The neutron is the simplest nuclear system that can be used to probe the structure of the weak interaction and search for physics beyond the standard model. Measurements of neutron lifetime and β-decay correlation coefficients with precisions of 0.02% and 0.1%, respectively, would allow for stringent constraints on new physics. The UCNτ experiment uses an asymmetric magneto-gravitational UCN trap with in situ counting of surviving neutrons to measure the neutron lifetime, τn = 877.7s (0.7s)stat (+0.4/−0.2s)sys. We discuss the recent result from UCNτ, the status of ongoing data collection and analysis, and the path toward a 0.25 s measurement of the neutron lifetime with UCNτ.

Medium- and long-term results of high tibial osteotomy using Garches external fixator and gait analysis for dynamic correction in varus osteoarthritis of the knee

In arthritis of the varus knee, a high tibial osteotomy (HTO) redistributes load from the diseased medial compartment to the unaffected lateral compartment.

We report the outcome of 36 patients (33 men and three women) with 42 varus, arthritic knees who underwent HTO and dynamic correction using a Garches external fixator until they felt that normal alignment had been restored. The mean age of the patients was 54.11 years (34 to 68). Normal alignment was achieved at a mean 5.5 weeks (3 to 10) post-operatively. Radiographs, gait analysis and visual analogue scores for pain were measured pre- and post-operatively, at one year and at medium-term follow-up (mean six years; 2 to 10). Failure was defined as conversion to knee arthroplasty.

Pre-operative gait analysis divided the 42 knees into two equal groups with high (17 patients) or low (19 patients) adductor moments. After correction, a statistically significant (p < 0.001, t-test,) change in adductor moment was achieved and maintained in both groups, with a rate of failure of three knees (7.1%), and 89% (95% confidence interval (CI) 84.9 to 94.7) survivorship at medium-term follow-up.

At final follow-up, after a mean of 15.9 years (12 to 20), there was a survivorship of 59% (95% CI 59.6 to 68.9) irrespective of adductor moment group, with a mean time to conversion to knee arthroplasty of 9.5 years (3 to 18; 95% confidence interval ± 2.5).

HTO remains a useful option in the medium-term for the treatment of medial compartment osteoarthritis of the knee but does not last in the long-term.

Cite this article: Bone Joint J 2016;98-B:601–7.

Investigating how the attributes of self-associated drug complexes influence the passive transport of molecules through biological membranes

Relatively little is known about how drug self-association influences absorption into the human body. This study presented two hydrophobic membranes with a series of solutions containing different types of tetracaine aggregates with the aim of understanding how the attributes of supramolecular aggregate formation influenced passive membrane transport. The data showed that aqueous solutions of the unprotonated form of tetracaine displayed a significantly higher (p < 0.05) passive membrane transport compared to solutions with mixtures of the unprotonated and protonated drug microspecies (e.g. transport through the skin was 0.96 ± 0.31 μg cm⁻² min⁻¹ and 1.59 ± 0.26 μg cm⁻² min⁻¹ respectively). However, despite an enhanced rate of drug transport and a better membrane partitioning the unionised molecules showed a significantly longer (p < 0.05) lag time to membrane penetration compared solutions rich in the ionised microspecies. Analytical characterisation of the solutions applied to the apical surface of the membranes in the transport studies showed that larger tetracaine aggregates with smaller surface charge gave rise to the longer lag times. These large aggregates demonstrated more extensive intermolecular bonding and therefore, it was suggest that it was the enhanced propensity of the unionised species to form tightly bound drug aggregates that caused the delay in the membrane penetration.

Patients' decision making in total knee arthroplasty: a systematic review of qualitative research

Objectives

A patient-centred approach, usually achieved through shared decision making, has the potential to help improve decision making around knee arthroplasty surgery. However, such an approach requires an understanding of the factors involved in patient decision making. This review’s objective is to systematically examine the qualitative literature surrounding patients’ decision making in knee arthroplasty.

Methods

A systematic literature review using Medline and Embase was conducted to identify qualitative studies that examined patients’ decision making around knee arthroplasty. An aggregated account of what is known about patients’ decision making in knee arthroplasties is provided.

Results

Seven studies with 234 participants in interviews or focus groups are included. Ten themes are replicated across studies, namely: expectations of surgery; coping mechanisms; relationship with clinician; fear; pain; function; psychological implications; social network; previous experience of surgery; and conflict in opinions.

Conclusions

This review is helpful in not only directing future research to areas that are not understood, or require confirmation, but also in highlighting areas that future interventions could address. These include those aimed at delivering information, which are likely to affect the satisfaction rate, demand, and use of knee arthroplasties.

Cite this article: Bone Joint Res 2015;4;163–169.

Nonuniform radiation damage in permanent magnet quadrupoles

We present data that indicate nonuniform magnetization loss due to radiation damage in neodymium-iron-boron Halbach-style permanent magnet quadrupoles. The proton radiography (pRad) facility at Los Alamos uses permanent-magnet quadrupoles for magnifying lenses, and a system recently commissioned at GSI-Darmsdadt uses permanent magnets for its primary lenses. Large fluences of spallation neutrons can be produced in close proximity to these magnets when the proton beam is, intentionally or unintentionally, directed into the tungsten beam collimators; imaging experiments at LANL's pRad have shown image degradation with these magnetic lenses at proton beam doses lower than those expected to cause damage through radiation-induced reduction of the quadrupole strength alone. We have observed preferential degradation in portions of the permanent magnet quadrupole where the field intensity is highest, resulting in increased high-order multipole components.

A systematic review of plate versus intramedullary fixation in the treatment of midshaft clavicle fractures

The best method of fixation for clavicle fractures is not known. The purpose of this review was to examine the evidence comparing plate and intramedullary fixation for midshaft clavicle fractures. A search of MEDLINE in September 2011 identified five papers that compared plate and intramedullary fixation, and fulfilled our eligibility criteria, consisting of; one randomised controlled trial, two quasi-randomised controlled trials, and two retrospective studies. Level of evidence was assessed using the Scottish Intercollegiate Guidelines Network guidance and the Cochrane Bone, Joint and Muscle Trauma Group’s quality assessment tool. No attempt at meta-analysis was made due to the heterogeneity of the study populations and interventions. We found no difference between intramedullary fixation and plate fixation. There was a trend towards a lower complication rate with intramedullary fixation. On the basis of the available evidence, we would advocate both techniques for the treatment of midshaft clavicle fractures.

Effect of cotton padding on the setting properties of plaster slabs

Introduction

Plaster of Paris (PoP) impregnated bandages have been used to maintain the position of bones and joints for over a century. Classically, wool dressing is applied to the limb before the PoP, which can then be moulded to the desired shape. A modification of this practice is to wrap the PoP bandages circumferentially in cotton before wetting and applying to the patient in an attempt to reduce inhalation of plaster dust and reduce mess. However, this may affect the water content of the cast and therefore also its setting properties and strength. This study compared the setting properties of PoP casts when used with and without cotton wrapping.

Methods

Sixty specimens, compliant with the American Society for Testing and Materials standards for three-point bending tests, were prepared, with thirty wrapped in cotton. All were weighed before and after water immersion, and wrapped around a plastic cylinder to mimic limb application. Bending stiffness and yield strength was measured on a servohydraulic materials testing machine at 2, 6, 12, 24, 48 and 72 hours.

Results

The water content of cotton-wrapped plaster was significantly higher (50%) than that of standard plaster. It had significantly lower strength up to 24 hours and significantly lower stiffness up to 72 hours.

Conclusions

The initial decrease in strength and stiffness of the cast wrapped in cotton may comprise the ability of the backslab to hold the joint or bone in an optimal position. Any modification of the standard plaster slab application technique should allow for the potential adverse effects on the plaster setting properties.

A cross-sectional study of aggression levels in physicians and orthopaedic surgeons: impact on specialty selection and training?

Objectives

To determine if current validated psychometric evaluations could determine a difference in basic behavioural characteristics between surgical and medical specialties.

Design

Cross-sectional study.

Setting

Two district general hospitals and one University teaching hospital in England, UK.

Participants

Internal medicine (16) and trauma and orthopaedic (20) consultants.

Main outcome measures

Aggression levels as assessed by the Buss and Warren questionnaire. The self-administered questionnaire assesses aggression in terms of physical, verbal, anger, hostility, indirect hostility and an overall assessment of aggression.

Results

All participants had aggression scores below the population average. We found a significant difference (P < 0.01) in total level of aggression, with orthopaedic consultants scoring a mean of 61.1 (standard deviation [SD] 9.2) and physicians 51.3 (SD 9.5). When analysis of the five different subtypes of aggression was carried out, orthopaedic surgeons scored significantly higher in terms of verbal aggression (P = 0.005), hostility (P = 0.002) and indirect hostility (P = 0.03).

Conclusion

This study joins a growing evidence base for aspects of behaviour indicative of a given specialty. Aggression is a relatively stable behavioural characteristic from adolescence, and as such this is the first study of its type to suggest that the differences in behavioural characteristics seen between specialties are inherent, rather than learned. It is unclear if the differences observed represent an attraction of that specialty to the personality type or is required for success within the given specialty. Whether this can be used in terms of selection into higher specialty training, or influence training within specialties, requires further work.

Acceptability and outcome of an Internet-based smoking cessation programme

SETTING

Three district health boards (DHBs), organisations that govern public hospitals and services in Auckland, New Zealand.

OBJECTIVE

To evaluate a commercial web-based smoking cessation programme (Smokestop).

DESIGN

Smokestop was offered free of charge to 126 staff members of three Auckland DHBs who wanted to stop smoking. Following a 30 minute face-to-face enrolment meeting, participants were able to log on and use the programme. Nicotine replacement therapy (NRT) was available at no cost. All participants who used the programme at least once were followed up at 1, 3 and 6 months after first logging on for assessment of smoking status by self-report verified by carbon monoxide (CO) in expired breath.

RESULTS

Of 104 participants who logged onto the programme, 12 (12%) achieved 6-month continuous CO-validated abstinence. Participant feedback was largely positive: 46% agreed that the programme had assisted them and 74% stated they would recommend it to other smokers. The concomitant use of NRT was seen as an important component.

CONCLUSIONS

The results suggest that this internet-based smoking cessation programme is an acceptable method to deliver behavioural support to people who want help in stopping smoking, and that it shows promise as a smoking cessation intervention.

Capillary electrophoresis as a metabolomic tool in antioxidant therapy studies

The development of an approach by which two CE methods operating with opposite polarities and orthogonal capillary electrophoretic separation modes (method 1: normal polarity cyclodextrin modified MEKC (CD-MEKC) and method 2: reversed polarity CZE) for the sequential application to urinary samples from a type I diabetes metabolomics investigation is discussed. During method development, problematic MEKC profile drift issues arising from the high glucose content of the diabetic animal urine samples required some electrolyte modifications involving the use of hexafluoroisopropanol (HFIP) to circumvent the drift. Data derived from both methods were subsequently subjected to alignment, normalization and multi-dimensional scaling (MDS) procedures. In such a way, classification of samples derived from control and diabetic animals receiving a placebo from those receiving an antioxidant nutraceutical, was successfully demonstrated. Such a strategy is a cost effective and comprehensive metabolomics tool useful for describing UV absorbing metabolite disease-related changes in nutra/pharma-ceutical studies.

Surgical approach to hysterectomy for benign gynaecological disease

BACKGROUND

There are three approaches to hysterectomy for benign disease - abdominal hysterectomy (AH), vaginal hysterectomy (VH) and laparoscopic hysterectomy (LH). Laparoscopic hysterectomy has three further subdivisions - laparoscopic assisted vaginal hysterectomy (LAVH) where a vaginal hysterectomy is assisted by laparoscopic procedures that do not include uterine artery ligation, laparoscopic hysterectomy (which we will abbreviate to LH(a)) where the laparoscopic procedures include uterine artery ligation, and total laparoscopic hysterectomy (TLH) where there is no vaginal component and the vaginal vault is sutured laparoscopically.

OBJECTIVES

To assess the most appropriate surgical approach to hysterectomy.

SEARCH STRATEGY

We searched the Cochrane Menstrual Disorders & Subfertility Group's Specialised Register of controlled trials (searched 23 March 2004), CENTRAL (The Cochrane Library Issue 1, 2004), MEDLINE (1966 to Mar 2004), EMBASE (1985 to Mar 2004), Biological Abstracts (1968 to Mar 2004), the National Research Register and relevant citation lists.

SELECTION CRITERIA

Only randomised trials comparing one surgical approach to hysterectomy with another were included.

DATA COLLECTION AND ANALYSIS

Twenty-seven trials that included 3643 participants were included. Independent selection of trials and data extraction were employed following Cochrane guidelines.

MAIN RESULTS

The benefits of VH versus AH were shorter duration of hospital stay (WMD 1.0 day, 95%CI 0.7 to 1.2 days), speedier return to normal activities (WMD 9.5 days, 95%CI 6.4 to 12.6 days), fewer unspecified infections or febrile episodes (OR 0.42, 95%CI 0.21 to 0.83). The benefits of LH versus AH were lower intraoperative bloodloss (WMD 45.3 mls, 95%CI 17.9 to 72.7 mls) and a smaller drop in haemoglobin level (WMD 0.55g/L, 95%CI 0.28 to 0.82g/L), shorter duration of hospital stay (WMD 2.0 days, 95%CI 1.9 to 2.2 days), speedier return to normal activities (WMD 13.6 days, 95%CI 11.8 to 15.4 days), fewer wound or abdominal wall infections (OR 0.32, 95%CI 0.12 to 0.85), fewer unspecified infections or febrile episodes (OR 0.65, 95%CI 0.49 to 0.87), at the cost of longer operating time (WMD 10.6 minutes, 95%CI 7.4 to 13.8 minutes) and more urinary tract (bladder or ureter) injuries (OR 2.61, 95%CI 1.22 to 5.60). There was no evidence of benefits of LH versus VH and the operating time was increased (WMD 41.5 minutes, 95%CI 33.7 to 49.4 minutes). There was no evidence of benefits of LH(a) versus LAVH and the operating time was increased for LH(a) (WMD 25.3 minutes, 95%CI 10.0 to 40.6 minutes). There was statistical heterogeneity in many of the outcome measures when randomised trials were pooled for meta-analysis. No other statistically significant differences were found. However, for some important outcomes, the analyses were underpowered to detect important differences, or they were simply not reported in trials. Data were notably absent for many important long-term outcome measures.

AUTHORS' CONCLUSIONS

Significantly improved outcomes suggest VH should be performed in preference to AH where possible. Where VH is not possible, LH may avoid the need for AH, however the length of the surgery increases as the extent of the surgery performed laparoscopically increases, particularly when the uterine arteries are divided laparoscopically and laparoscopic approaches require greater surgical expertise. The surgical approach to hysterectomy should be decided by a woman in discussion with her surgeon in light of the relative benefits and hazards. Further research is required with full reporting of all relevant outcomes, particularly important long-term outcomes, in large RCTs, to minimise the possibility of reporting bias. Further research is also required to define the role of the newer approaches to hysterectomy such as TLH.

Career choices for obstetrics and gynaecology: national surveys of graduates of 1974-2002 from UK medical schools

OBJECTIVE

To report the trends in career choices for obstetrics and gynaecology among UK medical graduates.

DESIGN

Postal questionnaire surveys of qualifiers from all UK medical schools in nine qualification years since 1974.

SETTING

United Kingdom.

POPULATION

All graduates from UK medical schools in 1974, 1977, 1980, 1983, 1993, 1996, 1999, 2000 and 2002.

METHODS

Postal questionnaire surveys.

MAIN OUTCOME MEASURES

Career choices for obstetrics and gynaecology and factors influencing career choices for obstetrics and gynaecology.

RESULTS

Seventy-four percent (24,623/33,417) and 73% (20,709/28,468) of doctors responded at 1 and 3 years after qualification. Choices for obstetrics and gynaecology fell sharply during the 1990s from 4.2% of 1996 qualifiers to 2.2% of 1999 qualifiers, and rose slightly to 2.8% of 2002 qualifiers. Only 0.8% of male graduates of 2002 chose obstetrics and gynaecology compared with 4.1% of women. Forty-six percent of those who chose obstetrics and gynaecology 1 year after qualification were working in it 10 years after qualifying. Experience of the subject as a student, and the influence of a particular teacher or department, affected long-term career choices more for obstetrics and gynaecology than for other careers.

CONCLUSIONS

The unwillingness of young doctors to enter obstetrics and gynaecology may be attributable to concerns about workforce planning and career progression problems, rather than any lack of enthusiasm for the specialty. The number of men choosing obstetrics and gynaecology is now very small; the reasons and the future role of men in the specialty need to be debated.

Levonorgestrel intrauterine system (LNG-IUS) with conjugated oral equine estrogen: a successful regimen for HRT in perimenopausal women

BACKGROUND

This study was designed to assess the long-term efficacy (5 years) of the levonorgestrel-releasing intrauterine system (LNG-IUS) in protecting the endometrium from hyperplasia during estrogen replacement therapy in perimenopausal women.

METHODS

Prospective, open, outpatient clinical trial in London and Oxford. Eighty-two women received oral conjugated equine estrogen 1.25 mg daily and LNG-IUS releasing 20 mug levonorgestrel per 24 h. Endometrial biopsy and histological assessment were performed annually. Endometrial thickness was measured by vaginal ultrasonography.

RESULTS

Non-proliferative endometrium was present at the end of cycles 12, 24, 36, 48 and 60 in 98.6, 98.6, 95.5, 96.8 and 95.2% of the participants respectively. No endometrial hyperplasias were confirmed throughout a period of 60 cycles. The proportion of amenorrhoeic women increased from 54.4% at 12 cycles to 92.7% at the end of the study. The continuation rate per 100 women at 60 cycles was 79.84 (95% CI 71.0-88.6).

CONCLUSIONS

The LNG-IUS with estrogen supplementation in perimenopausal women suppresses endometrial proliferation resulting in amenorrhoea and relieves vasomotor symptoms. The treatment regimen is well tolerated and provides an alternative strategy for perimenopausal women with the likelihood of increasing compliance.

Surgical approach to hysterectomy for benign gynaecological disease

BACKGROUND

There are three approaches to hysterectomy for benign disease - abdominal hysterectomy (AH), vaginal hysterectomy (VH) and laparoscopic hysterectomy (LH). Laparoscopic hysterectomy has three further subdivisions - laparoscopic assisted vaginal hysterectomy (LAVH) where a vaginal hysterectomy is assisted by laparoscopic procedures that do not include uterine artery ligation, laparoscopic hysterectomy (which we will abbreviate to LH(a)) where the laparoscopic procedures include uterine artery ligation, and total laparoscopic hysterectomy (TLH) where there is no vaginal component and the vaginal vault is sutured laparoscopically.

OBJECTIVES

To assess the most appropriate surgical approach to hysterectomy.

SEARCH STRATEGY

We searched the Cochrane Menstrual Disorders & Subfertility Group's Specialised Register of controlled trials (searched 23 March 2004), CENTRAL (The Cochrane Library Issue 1, 2004), MEDLINE (1966 to Mar 2004), EMBASE (1985 to Mar 2004), Biological Abstracts (1968 to Mar 2004), the National Research Register and relevant citation lists.

SELECTION CRITERIA

Only randomised trials comparing one surgical approach to hysterectomy with another were included.

DATA COLLECTION AND ANALYSIS

Twenty-seven trials that included 3643 participants were included. Independent selection of trials and data extraction were employed following Cochrane guidelines.

MAIN RESULTS

The benefits of VH versus AH were shorter duration of hospital stay (WMD 1.0 day, 95%CI 0.7 to 1.2 days), speedier return to normal activities (WMD 9.5 days, 95%CI 6.4 to 12.6 days), fewer unspecified infections or febrile episodes (OR 0.42, 95%CI 0.21 to 0.83). The benefits of LH versus AH were lower intraoperative bloodloss (WMD 45.3 mls, 95%CI 17.9 to 72.7 mls) and a smaller drop in haemoglobin level (WMD 0.55g/L, 95%CI 0.28 to 0.82g/L), shorter duration of hospital stay (WMD 2.0 days, 95%CI 1.9 to 2.2 days), speedier return to normal activities (WMD 13.6 days, 95%CI 11.8 to 15.4 days), fewer wound or abdominal wall infections (OR 0.32, 95%CI 0.12 to 0.85), fewer unspecified infections or febrile episodes (OR 0.65, 95%CI 0.49 to 0.87), at the cost of longer operating time (WMD 10.6 minutes, 95%CI 7.4 to 13.8 minutes) and more urinary tract (bladder or ureter) injuries (OR 2.61, 95%CI 1.22 to 5.60). There was no evidence of benefits of LH versus VH and the operating time was increased (WMD 41.5 minutes, 95%CI 33.7 to 49.4 minutes). There was no evidence of benefits of LH(a) versus LAVH and the operating time was increased for LH(a) (WMD 25.3 minutes, 95%CI 10.0 to 40.6 minutes). There was statistical heterogeneity in many of the outcome measures when randomised trials were pooled for meta-analysis. No other statistically significant differences were found. However, for some important outcomes, the analyses were underpowered to detect important differences, or they were simply not reported in trials. Data were notably absent for many important long-term outcome measures.

AUTHORS' CONCLUSIONS

Significantly improved outcomes suggest VH should be performed in preference to AH where possible. Where VH is not possible, LH may avoid the need for AH, however the length of the surgery increases as the extent of the surgery performed laparoscopically increases, particularly when the uterine arteries are divided laparoscopically and laparoscopic approaches require greater surgical expertise. The surgical approach to hysterectomy should be decided by a woman in discussion with her surgeon in light of the relative benefits and hazards. Further research is required with full reporting of all relevant outcomes, particularly important long-term outcomes, in large RCTs, to minimise the possibility of reporting bias. Further research is also required to define the role of the newer approaches to hysterectomy such as TLH.

Hormone replacement therapy in postmenopausal women: endometrial hyperplasia and irregular bleeding

BACKGROUND

The decline in circulating oestrogen around the time of the menopause often induces unacceptable symptoms that affect the health and well being of women. Hormone replacement therapy (both unopposed oestrogen and oestrogen and progestogen combinations) is an effective treatment for these symptoms. In women with an intact uterus, unopposed oestrogen may induce endometrial stimulation and increase the risk of endometrial hyperplasia and carcinoma. The addition of progestogen reduces this risk but may cause unacceptable symptoms, bleeding and spotting which can affect adherence to therapy.

OBJECTIVES

The objective of this review is to assess which hormone replacement therapy regimens provide effective protection against the development of endometrial hyperplasia and/or carcinoma with a low rate of abnormal vaginal bleeding.

SEARCH STRATEGY

We searched the Cochrane Menstrual Disorders and Subfertility Group trials register (searched January 2003), The Cochrane Library (Issue 2, 2003), MEDLINE (1966 to January 2003), EMBASE (1980 to January 2003), Current Contents (1993 to January 2003), Biological Abstracts (1969 to 2002), Social Sciences Index (1980 to January 2003), PsycINFO (1972 to February 2003) and CINAHL (1982 to January 2003). The search strategy was developed by the Cochrane Menstrual Disorder and Subfertility Group. Attempts were also made to identify trials from citation lists of review articles and drug companies were contacted for unpublished data. In most cases, the corresponding author of each included trial was contacted for additional information.

SELECTION CRITERIA

The inclusion criteria were randomised comparisons of unopposed oestrogen therapy, combined continuous oestrogen-progestogen therapy and sequential oestrogen-progestogen therapy with each other and placebo administered over a minimum treatment period of six months. Trials had to assess which regimen was the most protective against the development of endometrial hyperplasia/carcinoma and/or caused the lowest rate of irregular bleeding.

DATA COLLECTION AND ANALYSIS

Sixty RCTs were identified. Of these 23 were excluded and seven remain awaiting assessment. The reviewers assessed the thirty included studies for quality, extracted the data independently and odds ratios for dichotomous outcomes were estimated. Outcomes analysed included frequency of endometrial hyperplasia or carcinoma, frequency of irregular bleeding and unscheduled biopsies or dilation and curettage, and adherence to therapy.

MAIN RESULTS

Unopposed moderate or high dose oestrogen therapy when compared to placebo was associated with a significant increase in rates of endometrial hyperplasia with increasing rates at longer duration of treatment and follow up. Odds ratios ranged from (1 RCT; OR 5.4, 95% CI 1.4 to 20.9) for 6 months of treatment to (4 RCTs; OR 9.6, 95% CI 5.9 to 15.5) for 24 months treatment and (1 RCT; OR 15.0, 95% CI 9.3 to 27.5) for 36 months of treatment with moderate dose oestrogen (in the PEPI trial, 62% of those who took moderate dose oestrogen had some form of hyperplasia at 36 months compared to 2% of those who took placebo). Irregular bleeding and non adherence to treatment were also significantly more likely under these unopposed oestrogen regimens that increased bleeding with higher dose therapy. Although not statistically significant, there was a 3% incidence (2 RCTs) of hyperplasia in women who took low dose oestrogen compared to no incidence of hyperplasia in the placebo group. The addition of progestogens, either in continuous combined or sequential regimens, helped to reduce the risk of endometrial hyperplasia and improved adherence to therapy. At longer duration of treatment, continuous therapy was more effective than sequential therapy in reducing the risk of endometrial hyperplasia. There was evidence of a higher incidence of hyperplasia under long cycle sequential therapy (progestogen given every three months) compared to monthly sequential therapy (progestogen given every month). No increase in endometrial cancer was seen in any of t in any of the treatment groups during the duration (maximum of six years) of these trials. During the first year of therapy irregular bleeding and spotting was more likely in continuous combined therapy than sequential therapy. However, during the second year of therapy bleeding and spotting was more likely under sequential regimens.

REVIEWERS' CONCLUSIONS

There is strong and consistent evidence in this review that unopposed oestrogen therapy, at moderate and high doses, is associated with increased rates of endometrial hyperplasia, irregular bleeding and consequent non adherence to therapy. The addition of oral progestogens administered either sequentially or continuously is associated with reduced rates of hyperplasia and improved adherence to therapy. Irregular bleeding is less likely under sequential than continuous therapy during the first year of therapy but there is a suggestion that continuous therapy over long duration is more protective than sequential therapy in the prevention of endometrial hyperplasia. Hyperplasia is more likely when progestogen is given every three months in a sequential regimen compared to a monthly progestogen sequential regimen.

Association between endometriosis and N-acetyl transferase 2 polymorphisms in a UK population

The relationship between endometriosis and polymorphisms in the N-acetyl transferase 2 (NAT 2) gene was investigated in a UK population, as this gene has been previously implicated in the aetiology of the disease. Point mutations in the gene result in the variant alleles NAT 2 *5, *6 and *7 from the wild-type NAT 2 *4 allele. Homozygotes for the NAT 2 *4 wild type allele are fast NAT acetylators, while heterozygotes with one wild-type allele and a variant NAT 2 *5, *6 or *7 allele have reduced enzyme activity, and individuals with two variant alleles are slow acetylators. The NAT 2 *4/*6 genotype was significantly more common among affected women (35.2%) than population controls (8.1%; P = 0.0001) or unaffected women (4.2%; P = 0.02). Significantly more affected women (57.4%) were fast acetylators than were population controls (32.3%; P < 0.01) or unaffected women (33.3%; P < 0.05). These data suggest that altered NAT 2 enzyme activity may be a predisposition factor in endometriosis, or that NAT 2 alleles may be in linkage disequilibrium with a susceptibility allele in the same chromosomal region.

An iron-regulated ferric reductase associated with the absorption of dietary iron

The ability of intestinal mucosa to absorb dietary ferric iron is attributed to the presence of a brush-border membrane reductase activity that displays adaptive responses to iron status. We have isolated a complementary DNA, Dcytb (for duodenal cytochrome b), which encoded a putative plasma membrane di-heme protein in mouse duodenal mucosa. Dcytb shared between 45 and 50% similarity to the cytochrome b561 family of plasma membrane reductases, was highly expressed in the brush-border membrane of duodenal enterocytes, and induced ferric reductase activity when expressed in Xenopus oocytes and cultured cells. Duodenal expression levels of Dcytb messenger RNA and protein were regulated by changes in physiological modulators of iron absorption. Thus, Dcytb provides an important element in the iron absorption pathway.

Inequalities in rates of gonorrhoea and chlamydia between black ethnic groups in south east London: cross sectional study

OBJECTIVES

To examine differences in population based rates of gonorrhoea and chlamydia between black ethnic groups in Lambeth, Southwark and Lewisham Health Authority.

METHODS

Episodes of gonorrhoea or chlamydia recorded among attenders at 11 genitourinary clinics in south and central London from 1 January 1994 to 31 December 1995 were retrieved. Complete data on chlamydia were only available for women. Ethnic group was assigned according to census categories--white, black Caribbean, black African, black other, Asian, or other. We calculated yearly incidence rates for episodes of gonorrhoea and chlamydia in residents of Lambeth, Southwark and Lewisham Health Authority. Random effects Poisson regression models were used to examine associations between infection rates and age, ethnic group, and material deprivation.

RESULTS

During the study period there were 1996 episodes of gonorrhoea in men and women and 1376 episodes of chlamydia in women with complete data. For both infections rates among individuals from black Caribbean and black other ethnic groups were markedly higher than among black Africans. In men, the gonorrhoea rate among black Caribbean 20-24 year olds was 2348 (95% CI 1965 to 2831) episodes per 100,000 compared with 931 (95% CI 690 to 1288) in black African men and 111 (95% CI 100 to 124) per 100,000 in white men of the same age. Among women gonorrhoea rates were highest in black Caribbean 15-19 year olds (2612, 95% CI 2161 to 3190 per 100,000). In contrast, rates in black African women of the same age (331, 95% CI 154 to 846 per 100,000) were similar to those of white women (222, 95% CI 163 to 312). Chlamydia rates were also highest in black Caribbean 15-19 year old women (4579, 95% CI 3966 to 5314 per 100,000), compared with 1286 (95% CI 907 to 1888) in black African and 433 (95% CI 349 to 544) per 100,000 white women. Controlling for material deprivation and age only attenuated differences in rates between ethnic groups slightly.

CONCLUSIONS

There are marked differences in rates of gonorrhoea and chlamydia between different black ethnic groups, with higher rates in black Caribbeans than black Africans. This study supports the hypothesis that assortative sexual mixing patterns can restrict epidemics of sexually transmitted infections within ethnic groups. Differences in disease occurrence between black ethnic groups should be explored before combining data, even when numbers of episodes are small.

Attention, arousal and expectancies in anxiety and sexual disorders

This paper reviews experimental studies of sexual disorders and anxiety disorders. Studies were mainly carried out in the laboratories and clinics with which each of the two authors is associated. Sex and anxiety are rather antipodal emotions but contrary to traditional views, there is no reason to believe that anxiety disorders are driven by underlying sexual problems or that sexual problems are maintained by anxiety. Both sex research and anxiety research focused on selective processing of disorder relevant information in patients. More in particular, studies are clustered in three groups. First, the authors examined selective attention for threat-related material in anxious patients and for non-sex-related material in sexually dysfunctional patients. Second, the (mis)interpretation of response information in both disorders is compared. Finally the authors discuss biased expectancies in anxiety and sexual disorders. Symmetries and asymmetries are highlighted and lines for further research are sketched.

Antibiotic-resistant gonorrhoea

The gonococcus has become either relatively or completely resistant to many antibiotics. However, knowledge of prevailing local resistance patterns and region in the world of acquisition of infection means that effective treatment is always possible.

Implantation versus infiltration: the Sampson versus the endometriotic disease theory

It has been assumed that endometriosis is a progressive disease, with growth and development of lesions being inevitable once the disease has started. The implantation and the metaplasia theories describe the mechanism of initiation of endometriotic lesions, but do not explain the different clinical manifestations of endometriosis. To explain the variable expression, growth and development of lesions into severe disease, a new endometriotic disease theory is proposed. This theory suggests that progression of endometriosis to endometriotic disease is considered similar to the onset and progression of a benign tumour. In this theory, the most important factor in the development of endometriotic disease is not the initial implantation/metaplasia, but cellular changes such as mutations. According to this theory, endometriotic disease develops from endometriotic cells that have 'escaped' the influence of protective and regulatory factors in the peritoneal fluid.

Sialoblastoma of the submandibular gland: report of a case and review of the literature

Sialoblastomas are rare perinatal epithelial salivary tumors, with only 22 reported cases in the literature. While they have been reported to occur predominantly in the parotid gland, we present one case of sialoblastoma of submandibular gland origin. The surgical management of this patient is discussed. Histopathologic examination, including immunochemical, ultrastructural and cytogenetic studies, was performed. Pertinent literature is reviewed.

Is the natural twinning rate now stable?

As contribution to a recent debate (James, 1998; Murphy et al., 1997, 1998) the proportion of twins following ovulation induction (OI) or assisted conception (AC) in 1994 in Oxfordshire and West Berkshire was estimated, and by extrapolation the natural twinning rate in England and Wales was judged to have maintained a plateau phase since the 1970s. Similar figures for 1995 and 1996 from the same study, and hence a more stable local estimate, are now provided. The proportions, as before, were estimated from women's responses to a questionnaire within a case-control study, with ascertainment from general practitioners' records or hospital case-notes for non-responders or for those excluded from the study originally. In 1994, 1995 and 1996 the proportion of twins following OI/AC was overall 27% (24%, 30% and 27% respectively). Restriction to the 87% locally resident made no difference. The national crude twinning rate for those years was overall 13·3 per 1000 maternities (12·8, 13·6 and 13·4 respectively).