Caring for the carers: an evaluation of the recovery, readjustment and reintegration programme (R3P)

INTRODUCTION

The challenges faced by healthcare workers, not least during the response to the COVID-19 pandemic, have been extensively studied, and concerns continue to be highlighted in relation to their long-term mental health. Identifying the need to support their personnel, a leader-led structured programme of reflection: the recovery, readjustment and reintegration programme (R3P) was designed by the UK Defence Medical Services to mitigate the potential stressors associated with this outbreak and enhance the resilience of the workforce.

METHODS

128 military personnel completed an evaluation of R3P. A survey included measures of anxiety before and after the intervention, perceptions of the discussion themes and whether these brought a sense of closure to areas of distress, and attitudes to help-seeking.

RESULTS

Most respondents (86%-92%) rated the five discussion themes either 'helpful' or 'very helpful', 51% of respondents reported a sense of closure about an issue that had been causing distress and 72% of respondents felt better able to seek help should it be necessary. Evaluating the effect R3P had on anxiety, a Wilcoxon signed rank test elicited a statistically significant difference in anxiety pre-R3P and post-R3P; Z=-3.54, p<0.001. The median anxiety rating was 3.5 (IQR 4.75, 95% CI 1.25 to 6.00) before undertaking R3P, which decreased to 3 (IQR 4.75, 95% CI 1.00 to 5.75) after undertaking R3P. 39.1% of participants reported decreased anxiety, 18.8% reported increased anxiety and 42.2% reported no change.

CONCLUSION

This evaluation has identified several positive aspects to R3P with many personnel reporting a reduction in anxiety, a sense of closure and increased likelihood of help-seeking. Several participants did report an increase in anxiety and the long-term impact of R3P on mental health and well-being is unclear. Further mixed-methods evaluation incorporating a longer follow-up is required.

Can echocardiographic parameters predict mortality in COVID-19?

Introduction

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), otherwise known as the coronavirus (COVID-19) pandemic presents one of the greatest medical challenges of our generation. Whilst commonly causing a viral pneumonitis, myocardial damage has also been suggested by elevated serum troponin values greater than the 99th centile in up to 30% of individuals who require hospitalisation and correlates with increased mortality.

Purpose

We aim to identify whether transthoracic echocardiography (TTE) parameters can elucidate the phenomenon of abnormal troponin levels. Furthermore, we seek to characterise the most frequent demographic, biochemical, echocardiographic features and co-morbidities associated with adverse outcomes in this cohort.

Methods

A retrospective analysis was conducted utilising electronic patient records of consecutive hospitalised patients with a positive COVID-19 swab between 1st March and 31st October 2020 who underwent a TTE at our institution. Pertinent variables were collected including: the clinical indication, demographics including cardiovascular (CV) risk factors, peak troponin values and fundamental echocardiographic parameters.

Results

During this 8-month period, a total of 90 patients underwent a TTE. The mean age of the cohort was 63 years of age and 56% were male. More than half (56.6%) were admitted to the intensive care unit (ICU). A salient 41.1% (n=37) of our cohort succumbed to this devastating virus. Notably, 38.9% (n=35) were of black and minority ethnic origin (BAME). A striking 64.9% (n=24) of patients who died had hypertension. The mean troponin levels were 168.7 ng/L and 176.6 ng/L (0–34 ng/L) in the survivors and non-survivors group respectively. With regards to TTE, the left ventricular parameters were similar between both groups with a mean left ventricular ejection fraction (LVEF) of 60.6% in the non-survivors. Conversely, both right ventricular (RV) dysfunction (37.8%) and raised pulmonary artery systolic pressures (PASP) (51.4%) were markedly more frequent in the patients who perished due to COVID-19 infection.

Conclusion

Remarkably, in this extremely ill group of patients who died, 91.9% of patients had a preserved LVEF. There were no overt differences between troponin levels in the survivors and non-survivors. However, hypertension, RV dysfunction and raised PASP were distinctly more prominent in the non-survivors. Thus, providing insight that a normally functioning left ventricle does not preclude to poor outcomes. Overall, this single-centre retrospective study demonstrates that the echocardiographic phenotype associated with mortality is consistent with a severe respiratory illness rather than direct myocardial injury from COVID-19. A multi-modality imaging approach may facilitate the identification of adverse tissue characterisation changes associated with this novel virus as well as guiding further risk stratification and patient management on a case-by-case basis.

Funding Acknowledgement

Type of funding sources: None.

Is there a role for an advanced practitioner in UK military prehospital care?

Recruitment and retention of doctors have been highlighted as some of the leading causes of the current perceived crisis within civilian emergency care. Indeed, the NHS recognises the contribution made by other healthcare professionals by supporting accreditation in advanced practice to mitigate the risks associated with these capability gaps. Consequently, roles such as the advanced clinical practitioner are now well established. Previous research and clinical experience in the civilian sector suggest that the advanced practitioner (AP) role could be used within Defence. Operationally, the role could be advantageous for the Defence Medical Services in the delivery of deployed healthcare. However, there is no available research that defines the role of UK military APs and, more specifically, their potential to support deployed prehospital care. Further work is required to determine how an AP might be effectively used within the military prehospital patient care pathway.

Rayleigh-Taylor instability experiments on the LULI2000 laser in scaled conditions for young supernova remnants

We describe a platform developed on the LULI2000 laser facility to investigate the evolution of Rayleigh-Taylor instability (RTI) in scaled conditions relevant to young supernova remnants (SNRs) up to 200 years. An RT unstable interface is imaged with a short-pulse laser-driven (PICO2000) x-ray source, providing an unprecedented simultaneous high spatial (24μm) and temporal (10 ps) resolution. This experiment provides relevant data to compare with astrophysical codes, as observational data on the development of RTI at the early stage of the SNR expansion are missing. A comparison is also performed with FLASH radiative magnetohydrodynamic simulations.

Nursing and medical contribution to Defence Healthcare Engagement: initial experiences of the UK Defence Medical Services

Introduction

The WHO Constitution enshrines ‘…the highest attainable standard of health as a fundamental right of every human being.’ Strengthening delivery of health services confers benefits to individuals, families and communities, and can improve national and regional stability and security. In attempting to build international healthcare capability, UK Defence Medical Services (DMS) assets can contribute to the development of healthcare within overseas nations in a process that is known as Defence Healthcare Engagement (DHE).

Methods

In the first bespoke DMS DHE tasking, a team of 12 DMS nurses and doctors deployed to a 1000-bedded urban hospital in a partner nation and worked alongside indigenous healthcare workers (doctors, nurses and paramedical staff) during April and May 2016. The DMS nurses focused on nursing hygiene skills by demonstrations of best practice and DMS care standards, clinical leadership and female empowerment. A Quality Improvement Programme was initiated that centred on hand hygiene (HH) compliance before and after patient contact, and the introduction of peripheral cannula care and surveillance.

Results

After a brief induction on the ward, it was apparent that compliance with HH was poor. Peripheral cannulas were secured with adhesive zinc oxide tape and no active surveillance process (such as venous infusion phlebitis (VIP) scoring) was in place. After intensive education and training, initial week-long audits were undertaken and repeated after a further 2 weeks of training and coworking. In the second audit cycle, HH compliance had increased to 69% and VIP scoring compliance to 99%. In the final audit cycle, it was noted that nursing compliance with HH (75/98: 77%) was significantly higher than the doctors’ HH compliance (76/200: 38%); p<0.0001.

Conclusions

DHE is a long-term collaborative process based on the establishment and development of comprehensive relationships that can help transform indigenous healthcare services towards patient-centred systems with a focus on safety and quality of care. Short deployments to allow clinical immersion of UK healthcare workers within indigenous teams can have an immediate impact. Coworking is a powerful method of demonstrating standards of care and empowering staff to institute transformative change. A multidisciplinary group of Quality Improvement Champions has been identified and a Hospital Oversight Committee established, which will offer the prospect of longer term sustainability and development.

A 'mixed reality' simulator concept for future Medical Emergency Response Team training

The UK Defence Medical Service's Pre-Hospital Emergency Care (PHEC) capability includes rapid-deployment Medical Emergency Response Teams (MERTs) comprising tri-service trauma consultants, paramedics and specialised nurses, all of whom are qualified to administer emergency care under extreme conditions to improve the survival prospects of combat casualties. The pre-deployment training of MERT personnel is designed to foster individual knowledge, skills and abilities in PHEC and in small team performance and cohesion in 'mission-specific' contexts. Until now, the provision of airborne pre-deployment MERT training had been dependent on either the availability of an operational aircraft (eg, the CH-47 Chinook helicopter) or access to one of only two ground-based facsimiles of the Chinook's rear cargo/passenger cabin. Although MERT training has high priority, there will always be competition with other military taskings for access to helicopter assets (and for other platforms in other branches of the Armed Forces). This paper describes the development of an inexpensive, reconfigurable and transportable MERT training concept based on 'mixed reality' technologies-in effect the 'blending' of real-world objects of training relevance with virtual reality reconstructions of operational contexts.

Scaled laboratory experiments explain the kink behaviour of the Crab Nebula jet

The remarkable discovery by the Chandra X-ray observatory that the Crab nebula's jet periodically changes direction provides a challenge to our understanding of astrophysical jet dynamics. It has been suggested that this phenomenon may be the consequence of magnetic fields and magnetohydrodynamic instabilities, but experimental demonstration in a controlled laboratory environment has remained elusive. Here we report experiments that use high-power lasers to create a plasma jet that can be directly compared with the Crab jet through well-defined physical scaling laws. The jet generates its own embedded toroidal magnetic fields; as it moves, plasma instabilities result in multiple deflections of the propagation direction, mimicking the kink behaviour of the Crab jet. The experiment is modelled with three-dimensional numerical simulations that show exactly how the instability develops and results in changes of direction of the jet.

The periodical change of the Crab nebula's jet direction challenges our understanding of astrophysical jet dynamics. Here the authors use high-power lasers to create a jet that can be directly compared to the Crab nebula's, and report the detection of plasma instabilities that mimic kink behaviour.

The patient experience: measuring the quality of care in the Defence Medical Services

Healthcare provided by the Defence Medical Services (DMS) is acknowledged to be of a high standard but patients' experiences of it has not been measured and collated in a consistent and meaningful way, which has limited strategic quality improvement initiatives. Responsibility for implementing and delivering a programme of healthcare governance and assurance for the DMS rests with the Inspector General (IG). An important aspect of this role is to nurture a culture of continuous improvement in the DMS and under this leadership the IG team has prioritised a number of projects to address this. The project to improve patient experience data capture was prioritised in the work schedule as it incorporated initiatives that would lead to improved quality in DMS healthcare, information exploitation and ultimately patient safety. This is the first in a series of articles that will document this important work and describe the methodological considerations associated with the initial questionnaire design, collaboration with NHS partners, the pilot study and progress towards the introduction of the definitive DMS tool later this year.

Coupling of high-intensity laser light to fast electrons in cone-guided fast ignition

Cu wires attached to Al cones are used to investigate the energy coupling efficiency of laser light to fast electrons through a cone into a dense plasma. We present experimental and simulation results demonstrating the effect on the energy coupling of effectively placing the cone in a surrounding high density plasma as well as the effect of a large preformed plasma inside the cone. Thick cone walls, simulating plasma surrounding the cone in fast ignition, reduce the energy coupling by a factor of up to 4. An increase in prepulse inside the cone by a factor of 50 further reduces coupling by a factor of 3. Simulations with the pic code lsp that include the laser plasma interaction and the preformed plasma from the flash code show that electron refluxing in thin cone-wall targets enhances coupling to the wire. The implications for full-scale cone-guided fast ignition are discussed.

Association between the CYP1A1 gene polymorphism and susceptibility to emphysema and lung cancer

Aim-To investigate cytochrome P4501A1 (CYP1A1) polymorphism and susceptibility to emphysema and lung cancer.Methods-A novel polymerase chain reaction (PCR) for genotyping the CYP1A1 polymorphism, corresponding to putative low or high enzyme activity, was developed to genotype lung cancer resection samples which had been assessed macroscopically for the presence of centriacinar and panacinar emphysema. Samples were collected and genotyped from a group of patients with chronic obstructive airways disease. A control group of anonymous blood donations was genotyped to determine the basal levels of the polymorphism in the Scottish population.Results-The high activity allele of the CYP1A1 gene is associated with susceptibility to centriacinar emphysema and lung cancer but not panacinar emphysema. CYP1A1 polymorphism is not linked to lung cancer in the absence of emphysema, nor to chronic obstructive airways disease which is the clinical manifestation of emphysema, particularly of the panacinar type.Conclusions-Susceptibility to emphysema and lung cancer is associated with polymorphism of the P4501A1 gene. A trend towards damage of centriacinar pattern has been detected, which supports the theory that centriacinar emphysema results from local, direct damage to the respiratory bronchioles from exposure to cigarette smoke.

Universal intermittent properties of particle trajectories in highly turbulent flows

We present a collection of eight data sets from state-of-the-art experiments and numerical simulations on turbulent velocity statistics along particle trajectories obtained in different flows with Reynolds numbers in the range R{lambda}in[120:740]. Lagrangian structure functions from all data sets are found to collapse onto each other on a wide range of time lags, pointing towards the existence of a universal behavior, within present statistical convergence, and calling for a unified theoretical description. Parisi-Frisch multifractal theory, suitably extended to the dissipative scales and to the Lagrangian domain, is found to capture the intermittency of velocity statistics over the whole three decades of temporal scales investigated here.

Expression of proliferating cell nuclear antigen in lung cancer: a systematic study and correlation with DNA ploidy

Heterogeneity of expression of the proliferating cell nuclear antigen (PCNA) was assessed immunohistochemically in 156 tissue samples from 33 surgically resected pulmonary carcinomas using the monoclonal antibody 19A2. The DNA content of each of these samples was measured by flow cytometry. Mean PCNA expression was higher in squamous carcinomas than in adenocarcinomas but there was marked intra-tumour variation in PCNA index in almost all cases. Intra-tumour heterogeneity of DNA content was noted in 11 cases. The PCNA index of these cases (34.1) was higher than that of DNA homogeneous cases (19.4). The wide variation in PCNA expression between different samples within a tumour would indicate that systematic sampling and counting will be necessary in future immunohistochemical studies of cell proliferation in tumour material.

'RETCIF': a rapid, sensitive method for detection of viruses, applicable for large numbers of clinical samples

Rapid detection of viruses in clinical samples is important for continuing appropriate antiviral treatment and discontinuing unnecessary antibacterial treatment, as well as for excluding viral pathogens. Yet detection of viral agents may require numerous susceptible cell lines. Even with the shell vial culture method, it is cumbersome for handling large volumes of specimens. A procedure has been developed, which is time and cost-saving and uses specific cell lines in a 96-well microtitre plate and monoclonal antibodies (RETCIF-rapid enhanced tissue culture immunofluorescence). Each clinical sample was inoculated into 12 different wells with five different cell lines. Enhancement was achieved by sonication, centrifugation and hormonal supplementation to the medium used. Cytomegalovirus (CMV), herpes simplex virus (HSV) and respiratory viruses were detected by monoclonal antibodies on day 2, whilst varicella zoster virus (VZV) and enteroviruses were detected on days 5 and 7, respectively. During July-December 1998, 3298 patient specimens were compared by RETCIF and a modified shell vial method. Either or both methods isolated 779 viruses (24% positivity rate), whilst both methods detected 621. Of the 779 viruses, 87% (679) were isolated by the shell vial method in an average time of 4.9 days. For RETCIF the respective rate was 92.5% (721), in an average time of 3.0 days. The RETCIF method is a time-saving procedure, with higher isolation rates than the shell vial method.

Strontium-89 treatment for prostate cancer bone metastases: does a prostate-specific antigen response predict for improved survival?

A review of 50 patients treated with strontium-89 for prostate cancer bone metastases from January 1993-1997 at the Wellington Cancer Centre was undertaken to determine if there was any correlation between changes in prostate-specific antigen (PSA) following treatment and subsequent survival. Thirty cases were evaluable for PSA response. Of these, 14 had a fall in PSA following strontium-89 treatment, and their mean survival was 641 days. The remaining 16 patients did not demonstrate a post-treatment fall in PSA and their mean survival was 275 days. A difference between these two groups in the time to development of new bone symptoms following treatment was also observed. No significant correlation between pretreatment PSA and PSA response was observed. In conclusion, a PSA response following strontium-89 treatment appears to predict for improved survival in patients with bone metastases from carcinoma of the prostate. Further prospective studies are indicated.

Multi-turn all-reflective optical gyroscope

We use calculation and simulation to characterize an all-reflective monolithic gyroscopic structure that supports 3 sets of orthogonal, spatially dense and continuous helical optical paths. This gyroscope differs from current fiber optic and ring laser gyroscopes primarily in the free space multi-turn nature of the optical path. The design also creates opportunities for introducing gain while minimizing spontaneous emission noise from those gain regions. The achievable angular measurement precision for each axis, given ideal components and no gain, is calculated to be ~0.001 degrees /hr for a structure of ~6.5 cm diameter, ~1 watt average optical power, and a wavelength of 0.5 microm. For fixed power, the uncertainty scales as the reciprocal cube of the diameter of the structure. While the fabrication and implementation requirements are challenging, the needed reflectivities and optical surface quality have been demonstrated in more conventional optics. In particular, the low mass, compact character, and all reflective optics offer advantages for applications in space.

Rates of GDP referral of complete dentures to a teaching hospital

PURPOSE OF STUDY

To identify areas and sites of excessive referral of complete dentures by GDPs, allowing for factors which might distort referral rates.

METHODS

Two hundred and six consecutive valid referrals of patients over the age of 50 years with complete dentures to a local dental teaching hospital and originating from the 29 Sheffield electoral wards were audited from the beginning of 1995 to the end of 1997. The referring practitioner and electoral ward were recorded.

RESULTS

Referral rates were calculated according to the size of the 50+ population within each ward and were found to be normally distributed, following exclusion of two wards with much higher referral rates than normal (3.5 and 6 SDs [standard deviations] from the mean). After calculating mean numbers referred per full-time equivalent (FTE) GDP for all wards, practices and practitioners originating excessive numbers of referrals within a high-referring ward could be identified.

CONCLUSION

After taking into account factors which might permit a high referral rate to be acceptable, practices with inappropriately high referral rates can be identified and remedial teaching need pinpointed.

A quality assurance audit: phase III trial of maximal androgen deprivation in prostate cancer (TROG 96.01)

In 1997 the Trans-Tasman Radiation Oncology Group (TROG) performed a quality assurance (QA) audit of its phase III randomized clinical trial investigating the effectiveness of different durations of maximal androgen deprivation prior to and during definitive radiation therapy for locally advanced carcinoma of the prostate (TROG 96.01). The audit reviewed a total of 60 cases from 15 centres across Australia and New Zealand. In addition to verification of technical adherence to the protocol, the audit also incorporated a survey of centre planning techniques and a QA time/cost analysis. The present report builds on TROG's first technical audit conducted in 1996 for the phase III accelerated head and neck trial (TROG 91.01) and highlights the significant progress TROG has made in the interim period. The audit provides a strong validation of the results of the 96.01 trial, as well as valuable budgeting and treatment planning information for future trials. Overall improvements were detected in data quality and quantity, and in protocol compliance, with a reduction in the rate of unacceptable protocol violations from 10 to 4%. Audit design, staff education and increased data management resources were identified as the main contributing factors to these improvements. In addition, a budget estimate of $100 per patient has been proposed for conducting similar technical audits. The next major QA project to be undertaken by TROG during the period 1998-1999 is an intercentre dosimetry study. Trial funding and staff education have been targeted as the key major issues essential to the continued success and expansion of TROG's QA programme.

Acute toxicity and cost analysis of a phase III randomized trial of accelerated and conventional radiotherapy for squamous carcinoma of the head and neck: a Trans-Tasman Radiation Oncology Group study

The primary purpose of the present analysis was to assess the feasibility and acute toxicity of a pure accelerated fractionation regimen in a cooperative group setting. This analysis included the first 320 patients entered on to the Trans-Tasman Radiation Oncology Group (TROG) randomized controlled trial which compared accelerated radiotherapy (ART) with conventional radiotherapy (CRT) in stage III and IV squamous cell carcinoma (SCC) of the head and neck. Patients were randomized to either 59.4 Gy in 33 fractions over 24 days (ART) or to 70 Gy 35 fractions over 49 days (CRT) after being stratified for site and stage. Accrual began in 1991 and the trial was closed on 3 April 1998 with the targeted 350 patients. The 3-year survival for the whole group was 54%, and the 3-year disease-free survival was 41%. Toxicity data were available on 303 patients (148 ART; 155 CRT). Mucosal toxicity was worse in the accelerated arm, and it peaked approximately 3 weeks earlier than the conventional arm. Skin toxicity was equivalent but occurred approximately 7 days earlier in the accelerated arm. Acute effects in both arms healed completely. Hospitalization was more common in the ART arm (71 vs 52 patients; P = 0.01) but the total bed days in hospital was not greatly different (1707 bed days for ART and 1607 bed days for CRT). Patients were more likely to require nasogastric (NG) feeding in the ART arm (49 vs 33 patients; P = 0.02). There were 1157 NG feeding days for ART and 1154 NG feeding days for CRT. The average cost of radiation treatment per patient including hospitalization, NG feeding and accommodation was $11,750 in the ART arm and $11,587 in the CRT arm. The accelerated arm has been shown to be a tolerable, practical and cost-equivalent regimen. The assessment of the therapeutic ratio of this accelerated protocol (ART) will be determined when the analysis of late effects and loco-regional control is made when the data are more mature.

Quality assurance audit in an Australasian phase III trial of accelerated radiotherapy for head and neck cancer (TROG 91.01). Trans-Tasman Radiation Oncology Group

The Trans-Tasman Radiation Oncology Group (TROG) initiated a randomized trial, testing accelerated (twice daily) radiotherapy against conventional radiotherapy for stage III and stage IV squamous cell carcinoma of the head and neck in 1991. In 1996, the Trial Management Committee arranged for a technical audit of 76 cases from 11 institutions, conducted by investigators from interstate institutions. A 10% unacceptable protocol violation rate was detected, which compares favourably with initial Radiation Therapy Oncology Group (RTOG) experience in the late 1970s. Infrastructural deficits with poor quality of documentation, incomplete retrieval of films and document return have been demonstrated in some cases. The Trans-Tasman Radiation Oncology Group is actively pursuing procedural and resourcing issues in order to redress this and is actively expanding its Quality Assurance (QA) Programme with an intercentre dosimetry study. Ultimately, comprehensive clinical and technical QA site visits are planned.

Simultaneous adjuvant radiotherapy and chemotherapy for stage I and II breast cancer

The purpose of the present paper was to evaluate treatment outcome after conservative breast surgery or mastectomy followed by simultaneous adjuvant radiotherapy and cyclophosphamide, methotrexate and fluorouracil (CMF) therapy. Two hundred and sixty eight (268) patients were treated at two Australian and two New Zealand centres between 1981 and July 1995. One hundred and sixty-nine patients underwent conservation surgery and 99 had mastectomies. Median follow-up was 53 months. Conventionally fractionated radiation was delivered simultaneously during the first two cycles of CMF, avoiding radiation on the Fridays that the intravenous components of CMF were delivered. In conservatively treated patients, 5-year actuarial rates of any recurrence, distant recurrence and overall survival were 34.5 +/- 5.2%, 25.4 +/- 4.5% and 75.5 +/- 4.8%, respectively. Crude incidence of local relapse at 4 years was 6.3% and at regional/distant sites was 26.3%. Highest grades of granulocyte toxicity (< 0.5 x 10(9)/L), moist desquamation, radiation pneumonitis and persistent breast oedema were recorded in 10.7, 8.5, 8.9 and 17.2%, respectively. In patients treated by mastectomy, 5-year actuarial rates of any recurrence, distant recurrence and overall survival were 59.7 +/- 7.3%, 56.7 +/- 7.4% and 50.1 +/- 7%. The crude incidence of local relapse at 4 years was 5.6% and at regional/distant sites it was 45.7%. The issue of appropriate timing of adjuvant therapies has become particularly important with the increasing acknowledgement of the value of anthracycline-based regimens. For women in lower risk categories (e.g. 1-3 nodes positive or node negative), CMF may offer a potentially better therapy, particularly where breast-conserving surgical techniques have been used. In such cases CMF allows the simultaneous delivery of radiotherapy with the result of optimum local control, without compromise or regional or systemic relapse rates. Further randomized trials that directly address the optimal integration of the two modalities, such as the one carried out in Boston, are clearly necessary.

Frequency of glutathione S-transferase M1 deletion in smokers with emphysema and lung cancer

1. Genetic variation at the glutathione S-transferase M1 locus (GSTM1) has been associated with a number of apparently unrelated cancers, including lung cancer. Emphysema is a common lung disease often found concomitant with lung cancer. Both emphysema and lung cancer may result from chemical and oxidative damage caused by reactive species present in cigarette smoke or released from neutrophils recruited following cigarette smoke induced injury. GSTM1 may protect against such damage through detoxification of cigarette smoke components. Polymorphism of this gene may thus influence susceptibility not just to lung cancer, but to other forms of lung disease. 2. Resection specimens from a group of 168 lung cancer patients were assessed for the presence of macroscopic centriacinar and panacinar emphysema. DNA was extracted from archival material and genotyped for the GSTM1 polymorphism using the polymerase chain reaction. A control group of 384 anonymous blood donations was used to determine the frequency of the GSTM1 gene deletion in a random control population. Reverse transcription on lung tissue was performed to investigate mRNA expression of GSTM1 and GSTM4. 3. In 57 lung cancer cases with no emphysema there was no association with homozygous deletion of the GSTM1 gene (51% null in cancer and 53% null in control groups). However in 111 patients with emphysema and lung cancer there was an increase in the frequency of deletion (65%, P = 0.032) giving an odds ratio of 1.36(0.32-2.40). In 43 cases there was evidence of both centriacinar and panacinar emphysema. The frequency of GSTM1 deletion was 70% (Odds ratio 2.11, 0.97-3.25). Both GSTM1 and GSTM4 mRNAs were expressed in lung tissue. 4 These findings suggest that GSTM1 has a general but rather small protective effect against toxicological injury in the lung which is not specific to cancer. This is of relevance in considering the health effects of exposure to a wide range of reactive chemicals in the environment.

The pattern of K-ras mutation in pulmonary adenocarcinoma defines a new pathway of tumour development in the human lung

Codon 12 of the K-ras oncogene was screened for mutations in 65 surgically-resected primary pulmonary adenocarcinomas and in 32 tissue foci of alveolar atypical hyperplasia (AAH) by a polymerase chain reaction (PCR)-based method. Mutations in either position 1 or position 2 of codon 12 were detected in 16 tumours (25 per cent). When analysed by site of origin, mutations were seen in 9/26 (35 per cent) parenchymal and in 0/12 bronchial adenocarcinomas (P < 0-02), K-ras mutations were seen in five AAH lesions from four patients. DNA sequencing showed that the great majority of mutations in both adenocarcinomas and AAH were G-T transversions. These findings provide support for the classification of pulmonary adenocarcinomas into bronchial and parenchymal subtypes and also provide molecular evidence to support the importance of AAH in the development of parenchymal cancers.