A biomechanical study to compare spinal movement in a healthy volunteer during extrication between 'chain cabling' and 'roof off' methods of extrication

INTRODUCTION

Following a motor vehicle collision some patients will remain trapped. Traditional extrication methods are time consuming and focus on movement minimisation and mitigation. 'Chain cabling' is an alternative method of extrication used in some countries. The optimal extrication strategy and the effect of extrication methods on spinal movement is unknown. This study compares 'chain cabling' to the established roof removal method of extrication on spinal movement.

METHODS

Biomechanical data were collected using Inertial Measurement Units on a single healthy volunteer during multiple experiments. The extrication types examined were chain cabling and roof removal. Measurements were recorded at the cervical and lumbar spine, and in the anteroposterior (AP) and lateral (LR) planes. Total movement (travel), maximal movement, mean, standard deviation and confidence intervals are reported.

RESULTS

Eight experiments were performed using each technique. The smallest mean overall movements were recorded during roof-off extrication (cervical spine 0.6 mm for AP and LR, lumbar spine 3.9 mm AP and 0.3 mm LR). The largest overall mean movements were seen with chain cabling extrication (cervical spine AP 5.3 mm. LR 6.1 mm and lumbar spine 6.8 mm AP and 6.3 mm LR).

CONCLUSION

In this study of a healthy volunteer, roof-off extrication was associated with less movement than chain cabling. The movement associated with chain cabling extrication was similar to that previously collected for other extrication types.

Advanced clinical practitioners' inter-shift need for recovery: a cross-sectional survey in emergency medicine

BACKGROUND

Healthcare settings are high-risk environments for fatigue and staff burnout. The Need For Recovery (NFR) scale quantifies inter-shift recovery, which contributes to cumulative fatigue and may precede occupational burnout. Advanced clinical practitioners (ACPs) are an established feature of the emergency medicine workforce in the UK, however, little is known about factors affecting their inter-shift recovery, fatigue or how NFR correlates with formal burnout inventories.

METHODS

A prospective cross-sectional online survey of UK emergency medicine ACPs from 1 September to 30 September 2020. The primary aim was to determine the NFR of these ACPs. The secondary aims were to determine any statistical associations between NFR and selected variables, and whether NFR could reliably predict burnout using the Copenhagen Burnout Inventory (CBI) as a comparator.

RESULTS

There were 529 responses to the survey from 50 sites (response rate: 88%). The median NFR was 63.6 (95% CI 54.5-63.6). Lower NFR scores were found in ACPs who see both adults and children (54.5, 95% CI 45.4-63.6), work shifts of 7-10 hours (54.5, 95% CI 36.3-63.6) and who found it easy to park before work (54.5, 95% CI 45.5-54.5). Linear regression modelling indicated significant associations between shift length, ease of parking, ability to get breaks and feeling overwhelmed. Spearman's rho between NFR and CBI for personal and work-related burnout was 0.741 and 0.766 respectively. Correlation between NFR and patient-related burnout was less at 0.471.

CONCLUSION

This study has shown the second highest NFR score reported in any occupational group. Several factors have been identified that may potentially reduce NFR and could be changed by organisations. NFR could also be used to identify those suffering with occupational burnout.

A Delphi study of rescue and clinical subject matter experts on the extrication of patients following a motor vehicle collision

BACKGROUND

Approximately 1.3 million people die each year globally as a direct result of motor vehicle collisions (MVCs). Following an MVC some patients will remain trapped in their vehicle; these patients have worse outcomes and may require extrication. Following new evidence, updated multidisciplinary guidance for extrication is needed.

METHODS

This Delphi study has been developed, conducted and reported to CREDES standards. A literature review identified areas of expertise and appropriate individuals were recruited to a Steering Group. The Steering Group formulated initial statements for consideration. Stakeholder organisations were invited to identify subject matter experts (SMEs) from a rescue and clinical background (total 60). SMEs participated over three rounds via an online platform. Consensus for agreement / disagreement was set at 70%. At each stage SMEs could offer feedback on, or modification to the statements considered which was reviewed and incorporated into new statements or new supporting information for the following rounds. Stakeholders agreed a set of principles based on the consensus statements on which future guidance should be based.

RESULTS

Sixty SMEs completed Round 1, 53 Round 2 (88%) and 49 Round 3 (82%). Consensus was reached on 91 statements (89 agree, 2 disagree) covering a broad range of domains related to: extrication terminology, extrication goals and approach, self-extrication, disentanglement, clinical care, immobilisation, patient-focused extrication, emergency services call and triage, and audit and research standards. Thirty-three statements did not reach consensus.

CONCLUSION

This study has demonstrated consensus across a large panel of multidisciplinary SMEs on many key areas of extrication and related practice that will provide a key foundation in the development of evidence-based guidance for this subject area.

Sex-disaggregated analysis of the injury patterns, outcome data and trapped status of major trauma patients injured in motor vehicle collisions: a prespecified analysis of the UK trauma registry (TARN)

OBJECTIVES

To identify the differences between women and men in the probability of entrapment, frequency of injury and outcomes following a motor vehicle collision. Publishing sex-disaggregated data, understanding differential patterns and exploring the reasons for these will assist with ensuring equity of outcomes especially in respect to triage, rescue and treatment of all patients.

DESIGN

We examined data from the Trauma Audit and Research Network (TARN) registry to explore sex differences in entrapment, injuries and outcomes. We explored the relationship between age, sex and trapped status using multivariate logistical regression.

SETTING

TARN is a UK-based trauma registry covering England and Wales.

PARTICIPANTS

We examined data for 450 357 patients submitted to TARN during the study period (2012-2019), of which 70 027 met the inclusion criteria. There were 18 175 (26%) female and 51 852 (74%) male patients.

PRIMARY AND SECONDARY OUTCOME MEASURES

We report difference in entrapment status, injury and outcome between female and male patients. For trapped patients, we examined the effect of sex and age on death from any cause.

RESULTS

Female patients were more frequently trapped than male patients (female patients (F) 15.8%, male patients (M) 9.4%; p<0.0001). Trapped male patients more frequently suffered head (M 1318 (27.0%), F 578 (20.1%)), face, (M 46 (0.9%), F 6 (0.2%)), thoracic (M 2721 (55.8%), F 1438 (49.9%)) and limb injuries (M 1744 (35.8%), F 778 (27.0%); all p<0.0001). Female patients had more injuries to the pelvis (F 420 (14.6%), M 475 (9.7%); p<0.0001) and spine (F 359 (12.5%), M 485 (9.9%); p=0.001). Following adjustment for the interaction between age and sex, injury severity score, Glasgow Coma Scale and the Charlson Comorbidity Index, no difference in mortality was found between female and male patients.

CONCLUSIONS

There are significant differences between female and male patients in the frequency at which patients are trapped and the injuries these patients sustain. This sex-disaggregated data may help vehicle manufacturers, road safety organisations and emergency services to tailor responses with the aim of equitable outcomes by targeting equal performance of safety measures and reducing excessive risk to one sex or gender.

Do entrapment, injuries, outcomes and potential for self-extrication vary with age? A pre-specified analysis of the UK trauma registry (TARN)

Background

Motor vehicle collisions (MVCs), particularly those associated with entrapment, are a common cause of major trauma. Current extrication methods are focused on spinal movement minimisation and mitigation, but for many patients self-extrication may be an appropriate alternative. Older drivers and passengers are increasingly injured in MVCs and may be at an increased risk of entrapment and its deleterious effects. The aim of this study is to describe the injuries, trapped status, outcomes, and potential for self-extrication for patients following an MVC across a range of age groups.

Methods

This is a retrospective study using the Trauma Audit and Research Network (TARN) database. Patients were included if they were admitted to an English hospital following an MVC from 2012 to 2019. Patients were excluded when their outcomes were not known or if they were secondary transfers. Simple descriptive analysis was used across the age groups: 16–59, 60–69, 70–79 and 80+  years. Logistic regression was performed to develop a model with known confounders, considering the odds of death by age group, and examining any interaction between age and trapped status with mortality.

Results

70,027 patients met the inclusion criteria. Older patients were more likely to be trapped and to die following an MVC (p < 0.0001). Head, abdominal and limb injuries were more common in the young with thoracic and spinal injuries being more common in older patients (all p < 0.0001). No statistical difference was found between the age groups in relation to ability to self-extricate. After adjustment for confounders, the 80 + age group were more likely to die if they were trapped; adjusted OR trapped 30.2 (19.8–46), not trapped 24.2 (20.1–29.2).

Conclusions

Patients over the age of 80 are more likely to die when trapped following an MVC. Self-extrication should be considered the primary route of egress for patients of all ages unless it is clearly impracticable or unachievable. For those patients who cannot self-extricate, a minimally invasive extrication approach should be employed to minimise entrapment time.

Maximum movement and cumulative movement (travel) to inform our understanding of secondary spinal cord injury and its application to collar use in self-extrication

Background

Motor vehicle collisions remain a common cause of spinal cord injury. Biomechanical studies of spinal movement often lack “real world” context and applicability. Additional data may enhance our understanding of the potential for secondary spinal cord injury. We propose the metric ‘travel’ (total movement) and suggest that our understanding of movement related risk of injury could be improved if travel was routinely reported. We report maximal movement and travel for collar application in vehicle and subsequent self-extrication.

Methods

Biomechanical data on application of cervical collar with the volunteer sat in a vehicle were collected using Inertial Measurement Units on 6 healthy volunteers. Maximal movement and travel are reported. These data and a re-analysis of previously published work is used to demonstrate the utility of travel and maximal movement in the context of self-extrication.

Results

Data from a total of 60 in-vehicle collar applications across three female and three male volunteers was successfully collected for analysis. The mean age across participants was 50.3 years (range 28–68) and the BMI was 27.7 (range 21.5–34.6). The mean maximal anterior–posterior movement associated with collar application was 2.3 mm with a total AP travel of 4.9 mm. Travel (total movement) for in-car application of collar and self-extrication was 9.5 mm compared to 9.4 mm travel for self-extrication without a collar.

Conclusion

We have demonstrated the application of ‘travel’ in the context of self-extrication. Total travel is similar across self-extricating healthy volunteers with and without a collar. We suggest that where possible ‘travel’ is collected and reported in future biomechanical studies in this and related areas of research. It remains appropriate to apply a cervical collar to self-extricating casualties when the clinical target is that of movement minimisation.

Assessing spinal movement during four extrication methods: a biomechanical study using healthy volunteers

Background

Motor vehicle collisions are a common cause of death and serious injury. Many casualties will remain in their vehicle following a collision. Trapped patients have more injuries and are more likely to die than their untrapped counterparts. Current extrication methods are time consuming and have a focus on movement minimisation and mitigation. The optimal extrication strategy and the effect this extrication method has on spinal movement is unknown. The aim of this study was to evaluate the movement at the cervical and lumbar spine for four commonly utilised extrication techniques.

Methods

Biomechanical data was collected using inertial Measurement Units on 6 healthy volunteers. The extrication types examined were: roof removal, b-post rip, rapid removal and self-extrication. Measurements were recorded at the cervical and lumbar spine, and in the anteroposterior (AP) and lateral (LAT) planes. Total movement (travel), maximal movement, mean, standard deviation and confidence intervals are reported for each extrication type.

Results

Data from a total of 230 extrications were collected for analysis. The smallest maximal and total movement (travel) were seen when the volunteer self-extricated (AP max = 2.6 mm, travel 4.9 mm). The largest maximal movement and travel were seen in rapid extrication extricated (AP max = 6.21 mm, travel 20.51 mm).

The differences between self-extrication and all other methods were significant (p < 0.001), small non-significant differences existed between roof removal, b-post rip and rapid removal.

Self-extrication was significantly quicker than the other extrication methods (mean 6.4 s).

Conclusions

In healthy volunteers, self-extrication is associated with the smallest spinal movement and the fastest time to complete extrication. Rapid, B-post rip and roof off extrication types are all associated with similar movements and time to extrication in prepared vehicles.

A comparison of the demographics, injury patterns and outcome data for patients injured in motor vehicle collisions who are trapped compared to those patients who are not trapped

Background

Motor vehicle collisions (MVCs) are a common cause of major trauma and death. Following an MVC, up to 40% of patients will be trapped in their vehicle. Extrication methods are focused on the prevention of secondary spinal injury through movement minimisation and mitigation. This approach is time consuming and patients may have time-critical injuries. The purpose of this study is to describe the outcomes and injuries of those trapped following an MVC: this will help guide meaningful patient-focused interventions and future extrication strategies.

Methods

We undertook a retrospective database study using the Trauma Audit and Research Network database. Patients were included if they were admitted to an English hospital following an MVC from 2012 to 2018. Patients were excluded when their outcomes were not known or if they were secondary transfers.

Results

This analysis identified 426,135 cases of which 63,625 patients were included: 6983 trapped and 56,642 not trapped. Trapped patients had a higher mortality (8.9% vs 5.0%, p < 0.001). Spinal cord injuries were rare (0.71% of all extrications) but frequently (50.1%) associated with other severe injuries. Spinal cord injuries were more common in patients who were trapped (p < 0.001).

Injury Severity Score (ISS) was higher in the trapped group 18 (IQR 10–29) vs 13 (IQR 9–22). Trapped patients had more deranged physiology with lower blood pressures, lower oxygen saturations and lower Glasgow Coma Scale, GCS (all p < 0.001). Trapped patients had more significant injuries of the head chest, abdomen and spine (all p < 0.001) and an increased rate of pelvic injures with significant blood loss, blood loss from other areas or tension pneumothorax (all p < 0.001).

Conclusion

Trapped patients are more likely to die than those who are not trapped. The frequency of spinal cord injuries is low, accounting for < 0.7% of all patients extricated. Patients who are trapped are more likely to have time-critical injuries requiring intervention. Extrication takes time and when considering the frequency, type and severity of injuries reported here, the benefit of movement minimisation may be outweighed by the additional time taken. Improved extrication strategies should be developed which are evidence-based and allow for the expedient management of other life-threatening injuries.

Productivity of Advanced Clinical Practitioners in Emergency Medicine: A 1-year dual-centre retrospective analysis

BACKGROUND

The ACP role is relatively new in Emergency Medicine (EM) nationally (RCEM, 2017). This work sought to establish the productivity of EM ACPs within our service, to enable evidence-based workforce planning and national benchmarking of this aspect of the role.

METHODOLOGY

Data from 1st January 2018-31st December 2018 was retrospectively collected from two hospitals in the United Kingdom (UK) via electronic patient records. In addition to the number of patients seen by ACPs (attending), the number of patients who were seen by an ACP as a senior review (SR) was collected. The productivity was mapped to ACP experience, with patient acuity and disposal reported.

RESULTS

In the study period 239,951 patients were seen in the Emergency Departments (EDs) of the two study hospitals. Overall 20,442 (8.5%) patients received care from an ACP. Mean productivity was 1.03 patients per hour (attending) and 1.53 patients per hour (attending and senior review).

DISCUSSION

EM ACPs form part of the RCEM future workforce strategy to overcome some of the contemporary challenges in EM (Hassan, 2018). To our knowledge, this is the first study which has examined and reported the productivity of ACPs in UK EM.

CONCLUSION

This paper sets a national benchmark for other EDs by reporting ACP productivity and contributes to the evidence by reporting productivity in other clinician groups. The data presented may be helpful in future national workforce planning for UK EDs.

Rhabdomyolysis: a case-based critical reflection on its causes and diagnosis

Rhabdomyolysis is a rare and complex condition that involves injury of the skeletal muscle fibres, resulting in the release of substances such as creatine kinase and myoglobin. It is associated with acute kidney injury and mortality. This article describes the case of a 40-year-old man who presented to the emergency department after an overdose of tramadol hydrochloride. It uses critical reflection to explore traumatic and non-traumatic causes of rhabdomyolysis and reviews the literature relating to the diagnosis of rhabdomyolysis through laboratory and point-of-care testing. To ensure the timely identification of patients at risk of deterioration, emergency nurses need to be aware of the potential causes and the clinical signs and symptoms of rhabdomyolysis.

Full-thickness burns due to contact with gastric acid

This article describes the case of a 33-year-old man with cerebral palsy who sustained a full-thickness burn to his thorax as a result of lying in gastric acid that had leaked from a damaged percutaneous endoscopic gastrostomy feeding tube. The patient required referral to a tertiary burns centre for specialist management. The article highlights the potential harm caused by gastric acid and why some patients may be particularly vulnerable to such injuries.

Evidence-based management of patients with Colles' fractures in emergency departments: a case-based critical reflection

Distal forearm fractures are a common presentation in UK emergency departments (EDs). However, despite the frequency of this presentation there is considerable variation in management, which may reflect the lack of definitive evidence to support one method. This article provides a narrative review of the literature on these injuries and provides an evidence-based approach to how they can be managed by ED clinicians. The review was prompted by a case-based critical reflection and Driscoll's ( 2007 ) model what, so what, now what, is used to structure the article and learning.

Does use of the LUCAS device improve mortality in adult patients with out-of-hospital cardiac arrest?

Out-of-hospital cardiac arrest (OHCA) is a common occurrence in the UK, with 60,000 cases reported annually. To improve outcomes among these patients it is necessary to improve links in the cardiac arrest chain of survival. Cardiopulmonary resuscitation (CPR) is one of the main elements of this chain because it reduces further ischaemic insult in the brain and heart by contributing to blood flow. However, even the best manual CPR provides only 20%-30% of the normal cardiac output. Despite the emphasis on timely CPR at the correct rate and depth, delivery of compressions is suboptimal for many patients and mechanical devices may improve outcomes. This article critically appraises two important papers on the use of mechanical CPR for OHCA. It also suggests potential uses for this treatment option and areas for future research.

Lactate in the emergency department: a case-based critical reflection

Serum lactate levels are frequently measured in patients with undifferentiated conditions in emergency departments. This article uses a case-based reflection to critically analyse the role of lactate measurement in these patients. It examines the rationale for testing, and the potential causes of raised levels, to remind clinicians that this diagnostic intervention must be taken in the context of patients' clinical presentations and not in isolation.

Venous and arterial blood gases in respiratory failure

Arterial and venous blood gases are commonly performed operations in emergency departments. This case-based critical reflection examines the contemporary literature relating to the topic. An evidence-based approach to selecting the most appropriate test for each patient is discussed, aiming to minimise the need for unnecessary arterial sampling.

Management of acute heart failure in the emergency department

Acute heart failure (AHF) is a leading cause of hospital admission in the UK and is associated with significant mortality. The National Institute for Health and Care Excellence ( 2014 ) has published guidelines for the management of AHF but, after a clinical event in which a patient's management differed from that recommended in the guidelines occurred in the author's emergency department, he conducted a critical analysis of them. This article provides a case study of the clinical event, reviews the treatment methods adopted and explores the rationale for taking a different approach from that recommended in the guidelines. The evidence base for the use of diuretics, nitrates and non-invasive ventilation in the management of patients with AHF is also appraised.

Rapid sequence induction in urgent care settings

In the management of critically ill patients in emergency departments, rapid sequence induction (RSI) of anaesthesia is often required. This article examines the elements of RSI that are necessary before before endotracheal tube placement and reviews the findings of a national audit project, conducted by Royal College of Anaesthetists and Difficult Airway Society. It also considers the role of nurses in RSI procedures.

Extrication time prediction tool

BACKGROUND

Many patients will require extrication following a motor vehicle collision (MVC). Little information exists on the time taken for extrication or the factors which affect this time.

OBJECTIVE

To derive a tool to predict the time taken to extricate patients from MVCs.

METHODS

A prospective, observational derivation study was carried out in the West Midland Fire Service's metropolitan area. An expert group identified factors that may predict extrication time-the presence and absence of these factors was prospectively recorded at eligible extrications for the study period. A step-down multiple regression method was used to identify important contributing factors.

RESULTS

Factors that increased extrication times by a statistically significant extent were: a physical obstruction (10 min), patients medically trapped (10 min per patient) and any patient physically trapped (7 min). Factors that shortened extrication time were rapid access (-7 min) and the car being on its roof (-12 min). All these times were calculated from an arbitrary time (which assumes zero patients) of 8 min.

CONCLUSIONS

This paper describes the development of a tool to predict extrication time for a trapped patient. A number of factors were identified which significantly contributed to the overall extrication time.

Major trauma training for emergency nurses

The Midlands regional trauma network was established in March 2012 to improve and standardise the care offered to patients with major trauma. This article discusses the results of a survey of formal training in, and self-assessed knowledge of, trauma management among emergency department nurses working in the network. Less than one third of the nurses had received formal training against which standards can be benchmarked, and the article recommends that nurse education standards are reinstated as key performance indicators in the region.

The stages of extrication: a prospective study

BACKGROUND

Many patients will require extrication following a motor vehicle collision (MVC). Little information exists on the time taken for the various stages of extrication.

OBJECTIVE

To report the time taken for the various stages of extrication.

METHODS

A prospective, observational study carried out in the West Midland Fire Service's metropolitan area. Time points related to extrication were collected 'live' by two-way radio broadcast. Any missing data were actively gathered by fire control within 1 h of completion of extrication. This paper reports an interim analysis conducted after 1 year of data collection following a 3-month run-in and training period: data were analysed from 1 January 2011 to 31 December 2011 inclusive.

RESULTS

During the study period 228 incidents were identified. Seventy-nine were excluded as they met the predetermined exclusion criteria or had incomplete data collection. This left 158 extrications that were suitable for analysis. The median time for extrication was 30 min, IQR 24-38 min.

CONCLUSIONS

In patients requiring extrication following an MVC a median time of 8 min is typically required before initial limited patient assessment and intervention. A further 22 min is typically required before full extrication. Prehospital personnel should be aware of these times when planning their approach to a trapped patient.

Using computerised patient-alert system

SThe information technology systems used in most modern emergency departments alert staff to patients who require special management, including those with infections or histories of violence, or children on the child protection register. These systems can improve care for patients, protect staff and prevent infection, although their benefits must be weighed against the risks involved in storing sensitive data on computers. It is essential, therefore, that such systems are professionally maintained and updated. This article reports how one UK emergency department uses a computerised alert system to improve patient care.

Intraosseous approach to vascular access in adult resuscitation

Establishing vascular access is vital to maximise resuscitation in critically ill children and adults (LaRocco and Wang 2003), and failure can result in delays in life-saving treatment (Nutbeam and Daniels 2010). The traditional intravenous access method can be difficult to achieve in patients with circulatory collapse (LaRocco and Wang 2003) and failure rates in emergency situations vary between 10 and 40 per cent (Lewis 1986). Other routes, such as endotracheal and intramuscular, do not provide controlled and reliable administration rates (Leidel et al 2009). This article focuses on the increased use of intraosseous (IO) access in adult resuscitation. The IO route is described and the indications and contraindications considered. Common insertion sites and devices of IO access are discussed.

Therapeutic hypothermia in the treatment of cardiorespiratory arrest

Prompt treatment of patients with cardiorespiratory arrest can mean the difference between life and death. This article analyses the use of therapeutic hypothermia and aims to educate practitioners about its advantages and disadvantages as an immediate treatment.

A 6-year experience demonstrates the utility of screening for both cytogenetic and FMR-1 abnormalities in patients with mental retardation

Cytogenetic abnormalities were found in 81 of 2,757 cases (2.93%) screened for both cytogenetic and FMR-1 mutations because of mental retardation from 1992 to 1997. Of these, 38 (46.9%) were unbalanced autosomal abnormalities, 23 (28.4%) sex chromosomal abnormalities, and 20 (24.7%) balanced autosomal rearrangements. Five subtle deletions were found, of which three involved the long arm of chromosome 7 (7q22-q31.1). Although a high-resolution banding method was used for screening, we concluded that a banding level of 450-550, generally achieved in routine analysis, was sufficient to detect all of these abnormalities. Fragile-X DNA studies revealed CGG expansion mutations in 72 other cases (2.61%). Of the abnormals, 36 (50%) were males and 8 (11.1%) females with full mutations, and 12 (16.7%) were males and 16 (22.2%) females with premutations. Together, our cytogenetic and DNA screening gave 5.5% abnormal results. In this report, these findings are compared with similar surveys of 3,940 subjects from five previous studies. From the combined data of 6,697 cases, this testing approach should reveal nearly equal numbers of cytogenetic and fragile X abnormalities in approximately 6-7% of subjects. It is productive, cost-effective, and consistent with American College of Medical Genetics (ACMG) guidelines for screening of mentally handicapped individuals.

Recession and well-being

In this paper we address two related questions: how much do economic recessions affect the aggregate well-being of a population, and by what means? Using data from the 1973-77 Quality of Employment Panel of full-time workers who experienced the 1974-75 recession (N = 830), we answer these questions by using an analytic procedure that allows us to determine the percentage of total aggregate (mean) change in well-being attributable to various changes in sociodemographic statuses, labor market positions, and job characteristics. Results from this procedure showed significant increases in the mean levels of distress and dissatisfaction for this sample and that the largest percentages of change were accounted for by changes in job characteristics: about 20 percent of the total change in distress and 47 percent of the total change for dissatisfaction. In particular, increased job demands and increasingly inadequate pay made substantial contributions, with the latter alone accounting for a quarter of the total change in dissatisfaction. Unemployment experiences also contributed substantial, but smaller, percentages to the change in distress (10 percent).

A preliminary study on the effect of germination on saponin content and composition of lentils and chick peas

Two cultivars of chick peas (Cicer arietinum) and one cultivar of lentils (Lens culinaris) were subjected to germination in the dark for 6 days at 20 degrees C. Soyasaponin VI, also known as soyasaponin beta g, a DDMP- (2,3-dihydro-2,5-dihydroxy-6-methyl-4H-pyran-4-one-) conjugated form of soyasaponin I, was the only saponin detected in both the unprocessed and germinated seed. No significant changes in saponin content were observed for chick peas or lentils after a 6-day germination.

The macroeconomic context of job stress

Using data from the 1973-1977 Quality of Employment Panel Study, we test a model that conceptually links research on macroeconomic causes of stress with research on job structure causes of stress among employed workers. Results from LISREL 7 (Jöreskog and Sörbom 1989) indicate that, while both macroeconomic and job structure variables have significant cross-sectional and longitudinal effects on stress, the macroeconomic effects are almost entirely indirect in their effect on job structures. In particular, higher occupational unemployment rates increased stress and lowered life satisfaction indirectly through reduced decision latitude and increased job demands. Overall, results suggest that macroeconomic changes, such as recessions, can affect individual stress because they lead to changes in routine job structures that represent increased and continued exposure to stressful conditions.

An intact cysteine-rich domain is required for dystrophin function

The carboxyl terminus of dystrophin is encoded by a highly conserved, alternatively spliced region of the gene. The few rare mutations reported in this region are of interest in unraveling the function of the dystrophin molecule. An unusual case of infantile onset Duchenne muscular dystrophy (DMD) with an internal 3' genomic deletion, and a membrane localized non-functional dystrophin protein, was used to explore the functional activity of this region. The patient's cDNA sequence showed an intragenic 1824-bp deletion precisely excising the cysteine rich and alternatively spliced COOH-terminal domains of dystrophin. The unaltered final 2.7 kb of the patients transcript was defined as a single exon localized to two genomic fragments, with the 5.9 kb HindIII fragment containing the stop codon. To understand the significance of deletions in this important region of the dystrophin gene, we mapped the order and cDNA coordinates for the 3' genomic HindIII fragments encoding the cysteine rich and alternative splicing domains. This 3' gene map was used to compare the clinical phenotype of the other reported COOH-terminal deletions in the literature. Our analysis concludes that the cysteine-rich domain confers an important function for the dystrophin protein.

Physical and genetic characterization of the distal segment of the myotonic dystrophy area on 19q

The mutation involved in myotonic dystrophy (DM) has been mapped to the region between the ERCC1 DNA repair gene and the anonymous D19S51 locus on 19q13.3. Starting at locus D19S112 (probe pX75b), which served as a novel entry site for this chromosome region, we have established a cosmid contig of approximately 200 kb. In the contig, a gene expressed in the brain and a highly informative, 12-allele (TG)n variable simple sequence motif (VSSM) were identified. With this marker, designated X75b-VSSM, a highly characteristic size distribution of alleles linked with DM, which differed significantly from that on normal chromosomes, was observed. Combining our physical mapping and genetic data, we show that the X75b-VSSM marker is the closest distal to DM, thus excluding the DM mutation from the entire telomeric portion of the ERCC1-D19S51 region.

Is the carboxyl-terminus of dystrophin required for membrane association? A novel, severe case of Duchenne muscular dystrophy

Duchenne muscular dystrophy is a lethal X-linked recessive disorder caused by the deficiency of a component of the muscle fiber membrane cytoskeleton called dystrophin. Becker muscular dystrophy, a clinically milder disorder, results from dystrophin abnormalities rather than deficiency. We identified the first patient who is clearly an exception to these established clinical and biochemical correlates. The patient described clinically had particularly severe Duchenne dystrophy. Biochemically, his muscle contained substantial amounts of abnormal dystrophin (Becker-like). Characterization of the dystrophin protein and gene revealed a unique intragenic gene deletion resulting in a dystrophin protein missing the carboxyl-terminal domain. This patient's dystrophin seemed to have a deleterious "dominant" effect on his muscle: The presence of this abnormal protein was more damaging to the myofibers than the absence of dystrophin would have been. This patient challenges the current hypothesis that dystrophin associates with the plasma membrane solely via its carboxyl-terminus, yet supports the hypothesis that an intact carboxyl-terminus is crucial for correct dystrophin function.

Gene amplification as a mechanism of reversion at the HPRT locus in V79 Chinese hamster cells

Spontaneous phenotypic revertants of hypoxanthine phosphoribosyl-transferase (HPRT) temperature-sensitive V79 Chinese hamster cells were selected by plating a temperature-sensitive mutant in HAT medium at 39 degrees C. The incidence of such revertants was approximately 2 X 10(-4) per cell. The majority of the revertants examined had increases of between three- and tenfold in their specific activity of the enzyme, and they were able to grow continuously in the presence of HAT medium at 39 degrees C. When the revertants were cultivated in the absence of HAT, they recovered their HAT-sensitive phenotype and their lowered level of HPRT. Three of the revertants were examined for their temperature inactivation profiles, and all were found to have profiles identical to the ts parent, and quite different from the V79 wild type. The kinetic properties of the cell lines were studied: the Km for both PRPP and hypoxanthine was significantly different in the temperature-sensitive cells but was not significantly altered in the revertants with respect to the ts mutants. A specific antibody to Chinese hamster brain HPRT was employed in immunoprecipitation experiments. By measuring the point at which the immunoprecipitation of the antibody to HPRT was overcome by increasing concentrations of cell supernatant, it was possible to estimate the relative amount of enzyme molecules in the cell lines. From these data, it could be concluded that the revertants overproduced an enzyme with the same immunological properties as the ts line. Southern blots of the Hind III restricted DNA from the ts mutant and two revertant cell lines were examined with an HPRT cDNA probe. This established that the HPRT gene was amplified twofold in one of the revertants, and threefold in the other. However, if the revertants were reintroduced into nonselective medium, the gene copy number declined to one. Finally, northern blots of RNA extracted from the various cell lines demonstrated that the HPRT mRNA was augmented 1.5-fold in one revertant and 1.4-fold in the other. Reintroduction into non-selective medium resulted in a decline in mRNA level for the second mutant, whereas the first mutant appeared to be stabilized. We conclude that gene amplification and concomitant amplification of messenger RNA and enzyme levels are mechanisms of phenotypic reversion at the HPRT locus in Chinese hamster cells.