A68 HOW REAL ARE YOUR SURVEY RESPONDENTS? IDENTIFYING FRAUDULENT RESPONDENTS IN ONLINE SURVEYS – A CASE EXAMPLE IN INFLAMMATORY BOWEL DISEASE (IBD)

Background

Social media and online surveys are commonly used to recruit and collect data from patients and physicians about GI diseases – they are efficient, convenient, and less resource intensive compared to traditional recruitment approaches and paper surveys. However, online data fraud is increasing and difficult to identify. Online data fraud can include intentional duplicate responses/straight-lining/inattention, bots/malicious software, and professional survey takers who provide fraudulent responses to meet study eligibility.

Purpose

1) Illustrate challenges of identifying fraudulent respondents through an algorithm and verification process we developed for our survey in IBD. 2) Demonstrate potential impact of fraudulent respondents on data and results.

Method

Online survey of Canadian adults (>18 years) with IBD about healthcare processes for managing IBD hosted using Qualtrics. Recruitment was done in clinic and online (mailing lists, social media). A $25 giftcard was offered for participation due to low response after 3 months in field, after which a large influx of ‘respondents’ occurred. Most were fraudulent although not obvious at first. To mitigate further fraudulent responses, we added the following to our survey: reCAPTCHA score, repeated question (year of IBD diagnosis), duplicate ID score, fraud score and honeypot question.

Our algorithm to identify fraudulent responses included 13 binary ‘red flag’ variables: age <18 years, year of diagnosis < year of birth, 2 different year of diagnosis, invalid postal code, survey duration <10 minutes, survey duration 10-15 minutes, suspicious comments for open text questions (x2), duplicate email, suspicious email, duplicate ID score ≥30, fraud score ≥30, and failed honeypot question. These variables were used to generate a fraudulent response score (range: 0-13; 13=most likely fraudulent). ‘Respondents’ with scores >3 were categorized as likely fraudulent. Respondents with scores ≤3 were reviewed individually. Respondents flagged as likely real or unsure were emailed and asked to verify their age; those who correctly verified age were considered likely real and included in the final sample.

Result(s)

Of the 4334 ‘respondents’ who started the survey, based on fraudulent response score we identified 75% (n=3258) as likely fraudulent, 17% (n=727) as unsure and 8% (n=349) as likely real. After age verification, 76% (n=3297) were considered likely fraudulent, 14% (n=592) remained unsure, 10% (n=442) were considered likely real, and <1% (n=3) were duplicates of likely real respondents.

Conclusion(s)

Despite convenience, social media and online surveys can be prone to fraudulent responses, especially when incentives are offered. We developed an algorithm and verification process to identify fraudulent responses using an IBD survey example. Given that only 10% of the full sample was considered likely real, researchers using social media and online surveys should carefully examine data for fraudulent responses and apply strategies to mitigate risks.

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Disclosure of Interest

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Measuring step count: why it is important not to assume measures are reliable

BACKGROUND

The validity and reliability of pedometer software Apps versus the previously investigated spring lever and piezoelectric pedometers is unknown.

PURPOSE

To evaluate the validity and reliability (in adults aged 18-65) of two pedometer software Apps, the Walk Star and the Accupedo, with spring lever (Digi-Walker CW 700) and piezoelectric (Omron HJ-720ITC and Tanita PD-724) pedometers in the measurement of step count. The criterion for comparison was researcher tallied direct observation of step count using an electronic E3-EHT hand held tally counter.

METHODS

Eighteen participants walked for 5minutes on a treadmill at slow (2miles per hour) moderate (3miles per hour) and fast walking (4miles per hour) speeds and on urban streets and upon grass at a perceived "comfortable" walking speed.

RESULTS

Bland and Altman plots show wide limits of agreement observed for the Yamax CW 700, Accupedo App and Walk Star App, suggesting these pedometers are unsuitable for measuring step counts in individuals due to high random error (indicating low reliability). Narrow limits of agreement were observed for the Omron HJ-720ITC and the Tanita PD-724 pedometers compared against Tally count and were considered suitable for use.

CONCLUSION

The validity and reliability of pedometers cannot be assumed but must be tested and ensured before use in measuring step count.

Physiotherapy rehabilitation for osteoporotic vertebral fracture-a randomised controlled trial and economic evaluation (PROVE trial)

The trial compared three physiotherapy approaches: manual or exercise therapy compared with a single session of physiotherapy education (SSPT) for people with osteoporotic vertebral fracture(s). At 1 year, there were no statistically significant differences between the groups meaning there is inadequate evidence to support manual or exercise therapy.

INTRODUCTION

To evaluate the clinical and cost-effectiveness of different physiotherapy approaches for people with osteoporotic vertebral fracture(s) (OVF).

METHODS

>Prospective, multicentre, adaptive, three-arm randomised controlled trial. Six hundred fifteen adults with back pain, osteoporosis, and at least 1 OVF participated.

INTERVENTIONS

7 individual physiotherapy sessions over 12 weeks focused on either manual therapy or home exercise compared with a single session of physiotherapy education (SSPT). The co-primary outcomes were quality of life and back muscle endurance measured by the QUALEFFO-41 and timed loaded standing (TLS) test at 12 months.

RESULTS

At 12 months, there were no statistically significant differences between groups. Mean QUALEFFO-41: - 1.3 (exercise), - 0.15 (manual), and - 1.2 (SSPT), a mean difference of - 0.2 (95% CI, - 3.2 to 1.6) for exercise and 1.3 (95% CI, - 1.8 to 2.9) for manual therapy. Mean TLS: 9.8 s (exercise), 13.6 s (manual), and 4.2 s (SSPT), a mean increase of 5.8 s (95% CI, - 4.8 to 20.5) for exercise and 9.7 s (95% CI, 0.1 to 24.9) for manual therapy. Exercise provided more quality-adjusted life years than SSPT but was more expensive. At 4 months, significant changes above SSPT occurred in endurance and balance in manual therapy, and in endurance for those ≤ 70 years, in balance, mobility, and walking in exercise.

CONCLUSIONS

Adherence was problematic. Benefits at 4 months did not persist and at 12 months, we found no significant differences between treatments. There is inadequate evidence a short physiotherapy intervention of either manual therapy or home exercise provides long-term benefits, but arguably short-term benefits are valuable.

TRIAL REGISTRATION

ISRCTN 49117867.

Men's experiences of having osteoporosis vertebral fractures: a qualitative study using interpretative phenomenological analyses

Men and women with vertebral fractures due to osteoporosis are treated differently by society and health care professionals. This can lead to inequalities in health care and affects how men with fractures view themselves as people. We need to raise awareness that men get these fractures as well as women.

INTRODUCTION

There is a lack of research exploring the experience of osteoporosis from the male perspective. This study was undertaken to explore and describe the experiences of men with vertebral fractures due to osteoporosis, including their perceptions of diagnosis, treatment and changes in their sense of self.

METHODS

The study consists of in-depth semi-structured interviews with nine male participants of the PROVE (Physiotherapy Rehabilitation for Osteoporotic Vertebral Fracture) study. Interviews were digitally audio recorded and fully transcribed. Data were coded in accordance with an interpretative phenomenological analysis approach to analyses.

RESULTS

Three main themes are presented. (i) Osteoporosis is considered an old women's disease. (ii) Men are diagnosed and treated differently than women in the NHS. Health care inequalities exist. (iii) Changes in self can occur in men after vertebral fracture/s due to osteoporosis.

CONCLUSIONS

Greater awareness that men get this condition is needed in both society in general and also by health care professionals who often do not expect osteoporosis to affect men. Approaches to diagnosis and treatment need to be considered and improved to ensure that they become appropriate and effective for men as well as women.

Development of a functional rehabilitation intervention for post knee arthroplasty patients: COmmunity based Rehabilitation post Knee Arthroplasty (CORKA) trial

Knee osteoarthritis is a common cause of disability in older people and knee arthroplasty surgery in the UK is increasing. The CORKA trial is a randomised controlled trial of rehabilitation targeted at patients identified as being at risk of a poor outcome after knee arthroplasty. This paper describes the development and delivery of the CORKA intervention. It was informed by current evidence, relevant guidelines, expert and patient opinion, practical considerations and a pilot study. The intervention is a multicomponent rehabilitation programme with the main component being an exercise programme delivered to participants in their own home. It includes functional task practice, strategies to improve adherence and where appropriate the provision of appropriate aids and equipment.

Is the timed loaded standing test a valid measure of back muscle endurance in people with vertebral osteoporosis?

Timed loaded standing (TLS) is a suggested measure of back muscle endurance for people with vertebral osteoporosis. Surface electromyography revealed back muscles work harder and fatigue during TLS. The test end-point and total time were associated with back fatigue. The findings help demonstrate the concurrent validity of the TLS test.

INTRODUCTION

The TLS test is suggested as a measure of back muscle endurance for patients with vertebral osteoporosis. However, to date, no study has demonstrated that TLS does measure back extensor or erector spinae (ES) muscle endurance. We used surface electromyography (sEMG) to investigate the performance of the thoracic ES muscles during TLS.

METHODS

Thirty-six people with vertebral osteoporosis with a mean age of 71.6 (range 45-86) years participated. sEMG recordings were made of the ES at T3 and T12 bilaterally during quiet standing (QS) and TLS. The relative (%) change in sEMG amplitude between conditions was compared. Fatigue was evaluated by analysing the change in median frequency (MF) of the sEMG signal during TLS, and the correlation between maximal TLS time and rate of MF decline was examined.

RESULTS

Activity in the ES increased significantly during TLS at all electrode locations. During TLS, the MF declined at a mean rate of -24.2% per minute (95% C.I. -26.5 to -21.9%). The MF slope and test time were strongly correlated (r² = 0.71), and at test end, the final MF dropped to an average 89% (95% C.I. 85 to 93%) of initial MF. Twenty-eight participants (78%) reported fatigue was the main reason for stopping, and for eight (22%), it was pain.

CONCLUSIONS

This study demonstrates that TLS challenges the ES muscles in the thoracic region and results in ES fatigue. Endurance time and the point at which the TLS test ends are strongly related to ES fatigue.

Protocol for the Femoroacetabular Impingement Trial (FAIT): a multi-centre randomised controlled trial comparing surgical and non-surgical management of femoroacetabular impingement

AIMS

Femoroacetabular Junction Impingement (FAI) describes abnormalities in the shape of the femoral head-neck junction, or abnormalities in the orientation of the acetabulum. In the short term, FAI can give rise to pain and disability, and in the long-term it significantly increases the risk of developing osteoarthritis. The Femoroacetabular Impingement Trial (FAIT) aims to determine whether operative or non-operative intervention is more effective at improving symptoms and preventing the development and progression of osteoarthritis.

METHODS

FAIT is a multicentre superiority parallel two-arm randomised controlled trial comparing physiotherapy and activity modification with arthroscopic surgery for the treatment of symptomatic FAI. Patients aged 18 to 60 with clinical and radiological evidence of FAI are eligible. Principal exclusion criteria include previous surgery to the index hip, established osteoarthritis (Kellgren-Lawrence ≥ 2), hip dysplasia (centre-edge angle < 20°), and completion of a physiotherapy programme targeting FAI within the previous 12 months. Recruitment will take place over 24 months and 120 patients will be randomised in a 1:1 ratio and followed up for three years. The two primary outcome measures are change in hip outcome score eight months post-randomisation (approximately six-months post-intervention initiation) and change in radiographic minimum joint space width 38 months post-randomisation. ClinicalTrials.gov: NCT01893034. Cite this article: Bone Joint Res 2014;3:321-7.

A comparison of three search strategies to establish which approach was most effective in identifying trials for inclusion

Background:

The identification of randomised clinical trials for inclusion in systematic reviews has been challenging and laborious in the past. Many physiotherapy journals were not included in databases and resources such as PubMed and not all trials were registered. Multifaceted approaches, including searching multiple databases and hand searches of journals and conference proceedings, were often required. The recent updating of an earlier systematic review provided the opportunity to explore different approaches to search for trials. This report aims to compare three search strategies to identify which was most effective in identifying trials for inclusion in the review.

Methods:

Three search approaches were used to identify trials for a review evaluating physiotherapy exercise following discharge from hospital following hip arthroplasty. Date limitations were set from 2007 to November 2013. Approach 1: replicated the earlier multifaceted 2007 strategy 1, which searched databases using multiple search term combinations and hand searched journals and proceedings. Approach 2: was a librarian-led, online search of health databases. Approach 3: was a researcher-led, PubMed advanced search. The Cochrane library, BioMed Central (BMC), King's Fund, the Department of Health National Research Register and the ClinicalTRIALS.gov register were also searched. The search strategies were evaluated by search time and identification of trials that were included in the systematic review.

Results:

All three searches identified the articles included in the updated review, but 3 346 articles were screened using approach 1 395 in approach 2, and 1 450 in approach 3. Although the librarian-led strategy took longer to set up, the findings were more concise and the fewer articles took less time to screen. Trials registers identified ongoing studies but no new data for the review.

Conclusions:

Many physiotherapy journals are now included in PubMed. The librarian-led search was the most efficient and is recommended. If a librarian is unavailable, a PubMed advanced search is another effective, if more time consuming, option for anyone wanting to identify physiotherapy clinical trials.

Implications:

Physiotherapy trials from 2007 were identified using PubMed and online librarian-led searches meaning previously time-consuming, multifaceted search strategies may no longer be necessary to identify trials.

Blind outcome assessment: the development and use of procedures to maintain and describe blinding in a pragmatic physiotherapy rehabilitation trial

Objectives: (1) To develop trial protocols which promote the achievement of blind outcome assessment. (2) To report outcome assessor beliefs regarding group allocation at follow-up assessments. (3) To document and describe instances of unblinding occurring during the trial to assist and inform rehabilitation researchers and clinicians.

Design: Prospective longitudinal observational study.

Setting: An NHS Hospital Trust specializing in orthopaedic surgery.

Subjects: One hundred and seven patients participating in a prospective pragmatic randomized controlled trial investigating physiotherapy rehabilitation following total knee arthroplasty, plus three outcome assessors.

Interventions: A protocol was developed using available research and designed to minimize instances of unblinding during a physiotherapy rehabilitation trial. Administrative, office, patient and research staff procedures were included.

Main measures: Trial questionnaires measured blind outcome assessment responses at 3 and 12 months post surgery. The outcome assessor kept a field diary recording the events surrounding instances of unblinding. Data underwent descriptive and content analysis.

Results: Blind outcome assessment was believed successful for n = 74 (81.32%) assessments at 3-month follow-up, and n = 83 (91.21%) at 12 months. Forty instances ( n = 28 participants) of unblinding were described in the field diary. While the main cause of unblinding was participants telling the outcome assessor, in 12.5% of events the assessor drew the wrong conclusion regarding group allocation. Not all unblinding events were remembered at subsequent assessments, even in this relatively small trial.

Conclusions: Blind outcome assessment was considered achievable in this trial. Specific trial protocols enabled blinding beliefs to be reported and instances of unblinding to be described.

Chronic disease management programme in people with severe knee osteoarthritis: efficacy and moderators of response

AIMS

To establish (1) the efficacy of a six-week chronic disease management programme for knee osteoarthritis and (2) whether previous physiotherapy or being wait listed for surgery moderated the outcome of the programme.

DESIGN

A pretest, posttest design with multivariate statistical modelling.

PARTICIPANTS

One hundred and twenty-one people with severe osteoarthritis who were waiting, or being considered, for surgery.

METHODS AND MEASURES

Western Ontario Osteoarthritis Index (WOMAC) scores, arthritis self-efficacy, distress and a patient-rated global indicator of response were collected at baseline, 6 and 12 weeks. History of previous physiotherapy, waiting list status, symptom duration, New Zealand disease severity score, radiographic changes and self-perceived need for surgery were recorded at baseline.

RESULTS

There were moderate improvements in most outcomes; WOMAC function decreased by 0.29, WOMAC pain by 0.27, pain self-efficacy by 4.4, function self-efficacy by 5.6 and visual analogue scale (VAS) distress by 0.2 (effect sizes ranging from 0.3 to 0.5 at 12 weeks). Waiting list status was a significant modifier for function, pain, distress and self-related outcomes. Participants on the waiting list for surgery experienced lesser improvements. Previous physiotherapy was associated with greater improvements in WOMAC scores at six weeks, but not at 12 weeks.

CONCLUSION

The chronic disease management programme could be considered for people with severe knee osteoarthritis, but should be given prior to referral and placement on the waiting list for surgery. Previous physiotherapy should not preclude people from participating in a chronic disease management programme.

Does arthroplasty type influence knee joint proprioception? A longitudinal prospective study comparing total and unicompartmental arthroplasty

Proprioception was assessed after knee replacement to compare total (TKA) to unicompartmental (UKA) knee arthroplasty. Thirty-four patients were recruited; seventeen patients underwent TKA and seventeen patients underwent UKA. The patient's age was similar in both groups. Two measures of proprioception, joint position sense (JPS) and postural sway (PS) were measured. Function was assessed using the Oxford Knee Score (OKS). Measurements were taken pre-operatively and 6 months post-operatively on both the operated and contralateral leg. Pre-operatively, no differences in JPS or PS were found between groups or between limbs in either group. Post-operatively, both groups had significant improvement of JPS in the operated limb only (20% increase). The improvement in JPS was similar in both groups. PS also improved significantly in both groups although the improvement of PS in the UKA group was twice that for the TKA group. The OKS improved by a similar amount in both groups. Both UKA and TKA result in a significant improvement in proprioception. Dynamic aspects of proprioception improve more after UKA than TKA, which may explain, in part, why UKA patients have superior functional outcome to that of TKA patients.

A systematic review of lateral wedge orthotics--how useful are they in the management of medial compartment osteoarthritis?

Studies on the use of lateral wedge orthotics in the conservative management of medial compartment osteoarthritis are widely quoted. This approach, however, does not consider the disruption of the interaction between lower limb and foot and ankle function that lateral wedges would produce. This comprehensive, systematic review was therefore undertaken to evaluate all available literature to determine whether evidence exists to support their use. MEDLINE, EMBASE, CINAHL, Allied and Complimentary Medicine, PubMed, EBSCO HOST and PEDro, Abstracts of Reviews of Effects in the National Electronic Library for Health for Cochrane Reviews and manual searching were used to identify studies. was searched for trials in progress. Data extraction was performed by the three authors using a paper data extraction form which was based on the CONSORT statement and Critical Skills Appraisal Programme (CASP) guidelines. Overall, the results of this review suggest that, based on current evidence there are no major or long-term beneficial effects with the use of lateral wedges.

Efficacy of an accelerated recovery protocol for Oxford unicompartmental knee arthroplasty--a randomised controlled trial

Unicompartmental knee arthroplasty (UKA) is appropriate for one in four patients with osteoarthritic knees. This study was performed to compare the safety, effectiveness and economic viability of a new accelerated protocol with current standard care in a state healthcare system. A single blind RCT design was used. Eligible patients were screened for NSAID tolerance, social circumstances and geographical location before allocation to an accelerated recovery group (A) or standard care group (S). Primary outcome was the Oxford Knee Assessment at 6 months post operation, compared using independent Mann-Whitney U-tests. A simple difference in costs incurred was calculated. The study power was sufficient to avoid type 2 errors. Forty-one patients were included. The average stay for Group A was 1.5 days. Group S averaged 4.3 days. No significant difference in outcomes was found between groups. The new protocol achieved cost savings of 27% and significantly reduced hospital bed occupancy. In addition, patient satisfaction was assessed as greater with the accelerated discharge than with the routine discharge time. The strict inclusion criteria meant that 75% of eligible patients were excluded. However, a large percentage of these were due to the distances patients lived from the hospital.

Recovery of function after closed femoral shortening

This prospective, longitudinal study documents the muscle strength and baseline function of 18 patients undergoing closed femoral shortening for discrepancy in limb length. Patients were studied for two years following surgery. Function was measured by a self-reported questionnaire, timed tests of performance and measurements of muscle strength and power. After two years, the self-reported function and ability to complete timed functional tests had returned to or improved on the pre-operative values. Muscle strength remained slightly below the pre-operative value and was more marked in the quadriceps than the hamstrings. This study suggests that small decreases in muscle strength and power following closed femoral shortening do not adversely affect the patients' ability to perform everyday activities.

Functional recovery in patients with nonunion treated with the Ilizarov technique

There are few reports on function after limb salvage surgery using the Ilizarov technique, and none that document the pattern of recovery or predict when maximum function returns. This prospective, longitudinal study documents the baseline functional abilities of 40 consecutive patients with nonunion of a fracture in the lower limb. Patients were studied for at least two and a half years following the completion of surgery. Function was measured by timed tests of functional performance and by the Toronto Extremity Salvage Score self-reported patient questionnaire. Recovery was slowest in the early stages after removal of the frame and greatest between six months and one year. Statistically significant improvement continued up to, but not beyond two years. This observation has important implications for the length of follow-up incorporated into the rehabilitation programmes for patients, predictions of patient status in regard to compensation and for the design of future studies to evaluate functional outcome.

Functional recovery in patients with nonunion treated with the Ilizarov technique

There are few reports on function after limb salvage surgery using the Ilizarov technique, and none that document the pattern of recovery or predict when maximum function returns. This prospective, longitudinal study documents the baseline functional abilities of 40 consecutive patients with nonunion of a fracture in the lower limb. Patients were studied for at least two and a half years following the completion of surgery. Function was measured by timed tests of functional performance and by the Toronto Extremity Salvage Score self-reported patient questionnaire.

Recovery was slowest in the early stages after removal of the frame and greatest between six months and one year. Statistically significant improvement continued up to, but not beyond two years. This observation has important implications for the length of follow-up incorporated into the rehabilitation programmes for patients, predictions of patient status in regard to compensation and for the design of future studies to evaluate functional outcome.

Loss of knee range of motion in leg lengthening

STUDY DESIGN

Prospective longitudinal study.

OBJECTIVE

To determine factors predictive of loss of movement in a cohort of patients undergoing femoral lengthening.

BACKGROUND

Loss of joint movement due to poor adaptation of the muscle is a major problem during limb lengthening but remains poorly documented in the literature.

METHODS AND MATERIALS

A validated technique using a modified goniometer was used to measure knee motion. Measurements were taken before surgery, prelengthening, during lengthening, and at 6 and 12 months post frame removal. The subjects were 35 patients with a mean age of 22 years (+/-12.8 years), 23 men and 12 women, undergoing femoral lengthening by the Ilizarov method.

RESULTS

The pattern of recovery of knee range of movement that was observed showed that 88% of knee flexion was regained by 6 months, 92% of patients regained their knee flexion by 12 months, and 97% by 18 months. Significant loss of knee flexion occurred in the latent period prior to lengthening, mean loss 79 degrees (+/-22.8 degrees). All patients regained full knee extension by the end of lengthening, but 2 patients who had fixed flexion deformities of > 40 degrees developed posterior subluxation of the knee.

CONCLUSIONS

The unexpected loss of movement observed in the prelengthening period indicates that physical therapy efforts must be directed to this phase in order to accelerate the recovery of joint range and reduce the muscle-related complications that can occur during limb lengthening.

Repeatability of goniometer measurements of the knee in patients wearing an Ilizarov external fixator: a clinic-based study

OBJECTIVE

To examine the intra-tester and inter-tester reliability of three different methods of measurement of knee range of motion in patients undergoing limb reconstruction with the Ilizarov external fixator.

DESIGN

Twenty-five patients had the passive range of motion of their knee measured by 13 physiotherapists who were experienced in the use of goniometry. The testers were assigned into random pairs, each tester measured three or four patients who were allocated to them using the three different methods. These were: (1) a universal goniometer aligned against anatomical landmarks, (2) a universal goniometer aligned against the Ilizarov frame and (3) a modified universal goniometer.

SETTING

Orthopaedic limb reconstruction outpatient clinics.

SUBJECTS

Twenty-five patients undergoing limb reconstruction using an Ilizarov external fixator on both the femur and tibia.

RESULTS

Comparison of the three different goniometry methods showed that using a modified goniometer there was enhanced reliability compared with other methods. This method demonstrated good repeatability for both intra-tester and inter-tester measurements.

CONCLUSIONS

When serial measurements of knee range of motion are taken in patients wearing an Ilizarov external fixator the modified model of goniometer should be used.

Reducing the biomechanical stress of lifting by training

The effectiveness of two methods of training in reducing biomechanical stress during lifting was examined in a sample of 12 men aged 18-40 years. Subjects carried out three 40 min sessions, one session per day, of a simple symmetrical lifting task. No training was given before the first session, which acted as the control condition. before each of the next two sessions training was given in the form of either written guidelines or interactive personal tuition in a crossover design. Interaction of order with method was expected and was of interest. The effectiveness of each training method in relieving the stress of lifting was measured in four ways: by ratings of perceived exertion on the Borg scale; by video analysis of adherence to guideline kinematics; by chronic spinal compression measured by precision stadiometry; and by the relative compression force at L5/S1 calculated using Chaffin's model. Although the differences in the results of the four assessment methods make reservations necessary it is suggested that while brief personal tuition may demonstrably reduce lifting stress even in a simple lifting task, written guidelines for the untrained may be counterproductive and may interfere with habitual skills. It is recommended that the efficiency of lifting training methods be estimated objectively, such as by the methods employed here, before being adopted.

Isolation and characterization of an estrogen-regulated ribosome-associated inactivator of tRNA aminoacylation in the uterus

Estradiol (E2) induces an increase in the peptide elongation rate of isolated uterine ribosomes assayed in a cell-free protein synthesis system. An inhibitory factor, extracted from ribosomes of E2-deprived rats, was found to inhibit the peptide elongation reaction by acting on certain tRNAs to render them incapable of binding to aminoacyl-tRNA synthetases, thus reducing the availability of specific aminoacylated tRNAs required for the sequential translation of the codons in mRNA. The uterine ribosome-associated tRNA inactivator (RATI) has been partially purified and monoclonal antibodies (MABs) to RATI have been prepared. Specificity of the MABs for RATI was indicated by the inactivation of RATI in vitro by the anti-RATI MABs. RATI selectively inactivates deacylated, but not acylated, tRNAs and the inactivation does not appear to involve nuclease cleavage of the tRNA. Within 1 h after E2 treatment 50% of both RATI activity and immunoreactivity were lost from the uterine ribosome extracts, suggesting that E2 regulation of tRNA reutilization may occur through dissociation of RATI from the ribosomal site of tRNA deacylation or alteration in the structure of RATI resulting in inactivation both biologically and immunologically. We propose that RATI may function as an E2-regulatable 'switch' mechanism which inactivates, delays or defers the aminoacylation of certain tRNAs in the absence of E2 and which participates in the regulation of protein synthesis at the translational level by creating rate-limiting levels of certain tRNAs in the E2-deprived uterus.

Effect of estradiol and progesterone on long chain fatty acyl-coenzyme A levels in the rat uterus

Fatty acyl-CoAs are potential in vivo inactivators of glucose-6-phosphate dehydrogenase (G6PD). Ovariectomized mature rats (n = 74) were given 5 micrograms of estradiol intravenously, then killed 0, 24, 36, 48 and 72 h later. Control levels of myristoyl-, palmitoyl-, stearoyl-, arachidonoyl-, oleoyl- and linoleoyl-CoA were 0.6, 3.2, 4.7, 3.4, 2.4 and 3.0 micrograms/uterus and were increased 39, 110, 146, 100, 84 and 69% at 36-48 h, respectively. Levels of fatty acyl-CoAs in the rat uterus become elevated 36 h after estradiol treatment. At the same time G6PD changes from a stable enzyme to one that is irreversibly inactivated, possibly due to being rapidly degraded. Progesterone (2 mg subcutaneously every 12 h, n = 30), administered beginning at either 24 or 36 h after estradiol treatment, had no effect on estradiol-induced changes in myristoyl-, palmitoyl-, or stearoyl-CoA. Compared to the groups of rats treated with estradiol alone, animals treated with combinations of estradiol and progesterone exhibited higher levels of arachidonoyl-CoA after 48 h, and oleoyl-CoA and linoleoyl-CoA were greater after 72 h. Progesterone increased the estradiol-induced levels of unsaturated fatty acyl-CoAs suggesting that progesterone may induce uterine fatty acid desaturase activity and/or uptake of dietary fatty acids. Addition of fatty acyl-CoAs, at concentrations seen in vivo at 36-48 h after estradiol, to purified G6PD, causes irreversible G6PD inactivation.

Estradiol regulation of the synthesis of uterine proteins with clusters of proline- and glycine-rich peptide sequences

Estradiol (E2) regulates the synthesis of uterine proteins at both the transcriptional and translational levels. E2 induces an increase in the specific amino acid acceptor activity of uterine tRNA, with the largest increases seen for proline, glycine and methionine. The synthesis of three uterine proteins that are rich in proline and glycine, estrogen receptor, progesterone receptor and glucose-6-phosphate dehydrogenase, is induced by E2. E2-induced increases in these proteins were preceded by an correlated with stimulation of tRNA acceptor activity for proline and glycine and these responses were specifically and simultaneously inhibited by prior azaserine treatment, which inhibits the E2-induced repair and synthesis of the 3'-CCA acceptor terminus of tRNAs. The high frequency and clustering of proline and glycine residues in estrogen receptor, progesterone receptor and glucose-6-phosphate dehydrogenase suggests that the translating ribosomes may slow down during synthesis of these proteins due to limiting levels of these tRNAs in E2-deprived uteri.

Effect of estradiol on the amino acid-accepting activity of uterine tRNAs and their participation in protein synthesis

Estradiol (E2) induces a complementary increase in both the amount of mRNA and the rate of translation of the mRNA in the uterus of ovariectomized mature rats. The mechanism of the translational effect was evaluated by measuring the functional capacity of uterine tRNA isolated from control, E2 (1 h)- and E2 (14 h)-treated ovariectomized rats to support amino acid acceptor activity and uterine protein synthesis. The specific amino acid acceptor activity (SAA) of deacylated tRNA for 18 individual amino acids was determined using a tRNA-dependent rat liver tRNA synthetase preparation. The SAA was the same for all amino acids for uterine tRNA from control and E2 (1 h)-treated rats but was increased for uterine tRNA from E2 (14 h)-treated rats to levels that were 1.4-4.3 times the SAA of uterine tRNA from control rats. When uterine tRNA from control and E2 (14 h)-treated rats was incubated with purified tRNA nucleotidyltransferase, the SAA for all amino acids was increased an average of 1.6-fold for control tRNA and 0.3-fold for tRNA from E2 (14 h)-treated rats. The ability of uterine tRNA to support maximal rates of protein synthesis in tRNA-dependent uterine ribosome protein synthesis assay was increased by either in vivo treatment of the rats with estradiol or by in vitro repair of the 3'-CCA terminus of this tRNA by nucleotidyltransferase. These observations suggest that E2 may increase the rate of mRNA translation in the uterus, in part, by increasing the proportion of certain tRNAs with intact and functional 3'-CCA acceptor termini.

Ribosome-associated estradiol-binding components in the uterus and their relationship to the translational capacity of uterine ribosomes

Estradiol transiently increases the rate of peptide elongation on uterine ribosomes from ovariectomized mature rats during the first 2 h after hormone injection, suggesting the existence of direct or indirect estradiol receptor interaction with ribosomes. Characterization of estradiol-binding components on isolated uterine ribosomes, microsomes, and cytosol under identical assay conditions indicated that microsomes and cytosol contain estradiol-binding components with similar affinities for estradiol (Kd = 0.5 nM) and sucrose gradient sedimentation characteristics (3.8S and 5.2S for preparations incubated at 0 and 30 C for 1 h, respectively). Those on ribosomes exhibited a higher affinity for estradiol (Kd = 0.14 nM) and had heterogeneous and more dense sedimentation characteristics (5.5-6.0S). The ribosome-associated estradiol binder was clearly different from transformed cytosol and nuclear estradiol receptors based on sedimentation characteristics under identical conditions. Like cytosol and nuclear receptors, microsomal and ribosomal estradiol binding underwent exchange reactions in vitro at 30 C, but not at 0 C. All in vitro bound, but not all in vivo bound, [3H] estradiol could be exchanged from microsomes or ribosomes by estradiol. [3H]Estradiol could be exchanged from ribosomes by a variety of estrogens, but not by progestins, glucocorticoids, or androgens. The amount of estradiol-binding activity on ribosomes decreased after estradiol administration in vivo and was inversely correlated with the rate of peptide elongation by the ribosomes in a cell-free protein synthesis system. These results suggest that accumulation of an estradiol-binding protein, perhaps a nascent estradiol receptor, on ribosomes in the absence of in vivo estradiol may directly or indirectly inhibit the peptide elongation reaction.

Isolation of a precursor and a nascent chain form of glucose-6-phosphate dehydrogenase from rat uterus and regulation of precursor processing by estradiol

SDS-polyacrylamide gel electrophoresis of anti-glucose-6-phosphate dehydrogenase immunoprecipitates from radiolabeled uterine tissue extracts previously revealed three proteins: A, B and C, which were tentatively identified as a 60-64 kDa precursor form, a 57 kDa predominant form, and a 40-42 kDa nascent peptide form of the enzyme, respectively. A peptide-mapping technique was used to examine structural homologies among A, B and C. Following the labeling of uterine proteins with [35S]methionine, labeled proteins A, B and C were isolated by immunoprecipitation and electrophoresis. Each protein was individually co-digested with authentic, [3H]methionine-labeled glucose-6-phosphate dehydrogenase using papain, the resulting peptides were resolved by isoelectric focusing and the peptides from the two sources on each gel were compared using double-label counting methods. Proteins A, B and C had at least eight peptides in common, both proteins A and C had two additional peptides in common that were not present in protein B, and B protein had two peptides that were either absent or present in reduced amounts in digests of proteins A and C. The extensive structural homology and immunoreactivity of these proteins indicated that proteins A, B and C were all related to glucose-6-phosphate dehydrogenase. The presence of two extra peptides in proteins A and C suggested that these peptides may be derived from a common NH2-terminal leader sequence which was present in both the precursor and nascent peptide chains. The presence of two peptides that were present in protein B and absent from proteins A and C is easiest to explain if they are derived from the two ends of the molecule, with the corresponding peptides in proteins A and C containing additional peptide sequences that are 'normally' removed by endogenous proteolytic processing enzymes. Based on the relative time-course of synthesis of the three glucose-6-phosphate dehydrogenase-related proteins in control and estrogen-treated uteri, it appears that estradiol promotes an increase in the relative rate of transfer of label from protein A into B by stimulating the rate of processing of the precursor to the predominant form of the enzyme and enhances the rate of translational conversion of protein C into higher molecular weight forms.

Inhibition of the aminoacylation of selected tRNA molecules by an estrogen-regulated factor on uterine ribosomes. Regulation of aminoacylation of tRNA by estrogens

Administration of estradiol to ovariectomized mature rats for 1 h induces a transient increase in the peptide elongation rate on uterine ribosomes. An inhibitor of the peptide elongation rate, which appears to be regulated by estrogen treatment in vivo, can be extracted from ribosomes of estrogen-deprived rats. The extracted inhibitor or a native inhibitor-ribosome complex affects the rate of the peptide elongation reaction in a uterine cell-free protein synthesis system by inhibiting the ability of selected tRNAs in the assay to be charged with amino acids by their respective aminoacyl-tRNA synthetases. The degree of inhibition of charging of the affected tRNAs ranges from 22% to 78%, the order of inhibition being Pro greater than Val greater than Arg greater than Try greater than Leu greater than Glu greater than Ile greater than Gly greater than His greater than Ser greater than Lys. Inhibition results from a specific dose-dependent, and presumably reversible, effect of the inhibitor on tRNA, but not on the aminoacyl-tRNA synthetase. The effect does not result from removal of A-C-C terminal nucleotides from the 3' end of tRNA, but does inhibit the ability of selected tRNAs to bind to the aminoacyl-tRNA synthetases. We propose that regulation of the peptide elongation rate on uterine ribosomes by estradiol occurs through the estradiol-induced inactivation of a ribosome-associated inhibitor, which causes a reversible alteration to selected tRNAs. The modified tRNAs are unable to bind to their respective aminoacyl-tRNA synthetase to become charged with an amino acid thus causing the availability of selected aminoacyl-tRNAs to become rate-limiting in the sequential elongation of peptides.

Regulation of the peptide elongation reaction on uterine ribosomes by estrogens

Administration of 17 beta-estradiol to ovariectomized mature rats for 1 h induces an increased capacity of subsequently isolated uterine ribosomes to synthesize protein in a cell-free protein synthesis system. The increased rate of protein synthesis can be ascribed to an effect of estrogen on the rate of peptide elongation rather than synthesis of additional new peptides. The increased rate of peptide elongation is dependent upon the dose of estradiol over the range of 0.1 to 10 micrograms/animal, and exhibits hormone specificity; 17 beta-estradiol, diethylstilbesterol, estrone and estriol but not 17 alpha-estradiol, progesterone, dihydrotestosterone or corticosterone will induce the response. Removal of ribosome associated proteins by extraction with 0.5 M KCl results in activation of protein synthesis by uterine ribosomes from control rats to rates that are equal to that of ribosomes from estrogen-stimulated rats suggesting that ribosomes from control animals are in an inhibited state. The KCI extracted ribosomal factors from control animals inhibit the synthesis of protein by salt-washed uterine ribosomes when added back to the ribosomes prior to assay and the inhibitory properties of these factors are greater if derived from ribosomes of control rather than 1 h estradiol-treated rats. The extracted inhibitor is inactivated by heat, is insensitive to treatment with N-ethylmaleimide, is insensitive to micrococcal nuclease and is reversible. The early activation of uterine ribosomes by estrogen appears to result from either the removal or inactivation of a ribosome associated-peptide elongation reaction, inhibitory factor.

Glucose-6-phosphate dehydrogenase: partial characterization of the rat liver and uterine enzymes

Some properties of rat liver and uterine glucose-6-phosphate dehydrogenase (D-glucose-6-phosphate: NADP+ oxidoreductase, EC 1.1.1.49) have been determined. A procedure has been used for the purification of rat liver glucose-6-phosphate dehydrogenase to homogeneity (spec. act. 210-225 units/mg protein) from large amounts of liver (0.5-2 kg) with yields of up to 30%. Uterine glucose-6-phosphate dehydrogenase was obtained by immunoprecipitation methods and the properties of radioactively-labeled forms of this enzyme were then determined. The amino acid composition of the liver enzyme was found to be similar to that for the enzyme from other mammalian tissues. The liver and uterine enzymes have a subunit molecular weight of 57000 and a pI of 6.5. The NH2-terminal amino acid of both enzymes was found to be pyroglutamate.

Effect of sodium fluoride on glucose-6-phosphate dehydrogenase activity in the rat uterus

Intrauterine administration of 50 mumol of NaF to the ovariectomized mature rat causes a 2--3-fold increase in the total uterine glucose-6-phosphate dehydrogenase activity within 24 h. The response is characterized by a 4--6 h lag with a maximum effect from 24 to 36 h after a single treatment. Uterine glucose-6-phosphate dehydrogenase activity continues to increase with daily administration of NaF through 4 days. The NaF-induced response is blocked by prior intrauterine administration of cycloheximide but not actinomycin D suggesting that the enzyme activity increases by a post-transcriptional effect of NaF on de novo enzyme synthesis. Direct measurement of the effect of NaF on the rate of incorporation of [14C] leucine into immunoprecipitable uterine glucose-6-phosphate dehydrogenase indicates that NaF causes a 9-fold increase in the rate of enzyme synthesis during the interval from 12 to 16 h after treatment. The half-life of the enzyme as measured by the rate of loss of [1-14C] glutamate from previously labeled utreine glucose-6-phosphate dehydrogenase is decreased from 27 to 10 h by NaF. The NaF response does not seem to be mediated by activation of uterine adenylyl cyclase since theophylline does not potentiate the response and since intrauterine application of cyclic AMP does not mimic the response. The increase in enzyme activity is preceded by an increase in the rate of utilization of the hexose monophosphate shunt pathway as determined by the ratio of the the rates of oxidation of [1-14C]glucose to [6-14C] glucose to CO2 by uterine slices in vitro. The action of NaF on this pathway most likely resutls from inhibition of the glycolytic enzyme, enolase, and increased pathway utilization may be the factor which controls enzyme synthesis. When given in combination with other known inducers of uterine glucose-6-phosphate dehydrogenase such as estradiol and NADP+, NaF acts synergistically.

Regulation of glucose-6-phosphate dehydrogenase activity in uterine tissue in organ culture

An organ culture technique, employing a totally defined medium, was developed, in which the levels of glucose-6-P dehydrogenase (G6PD) activity in uterine tissue from estradiol-treated ovariectomized mature rats continued to increase in vitro for 18 h at a rate similar to that seen in vivo. Uterine G6PD levels did not increase in vitro in tissues from estrogen-deprived rats even if estradiol (10(-6)m) was added in vitro, but the administration of estradiol (5 mug/rat) in vivo for as little as 2 min permitted G6PD levels to increase by 0.03 units/uterus (from 0.075 to 0.10, units/uterus) after the 18 h incubation. The maximum increase of 0.08 units/uterus (from 0.147 to 0.230 units/uterus) was seen in uteri from rats which were given estradiol 12 h prior to sacrigice. Tissues from animals given estradiol for greater than 30 h exhibit a net decrease in G6PD levels under the in vitro conditions. The in vitro increase in G6PD activity is inhibited by the addition of either actinomycin D (5 mug/ml), cycloheximide (5 mug/ml), or cordycepin (150 mug/ml), or by the intrauterine injection of actinomycin D (10 mug/rat). Intrauterine administration of cycloheximide (100 mug/rat) inhibited the in vivo increase in enzyme activity; however, the enzyme levels increased after placement of uterine tissues from these animals into organ culture. The removal of cycloheximide, which was added at the beginning of incubation after the 12th h, restores the ability of the tissues to increase the G3PD activity, and this restoration is not blocked by the addition of actinomycin D, suggesting that the mRNA activity for uterine G6PD accumulated during in vitro inhibition of protein synthesis by cycloheximide. The in vitro increase in uterine G6PD is due to an increase in immunologically identifiable G6PD protein and this increase is due, at least in part, to an increase in the de novo synthesis of the enzyme, as measured by the incorporation of [14C]leucine into immunochemically isolated G6PD protein. These results suggest that once initiated in vivo by estradiol, the uterus is capable of continuing in vitro those events, including the synthesis of both RNA and protein, which result in an increased rate of synthesis of uterine G6PD.