Emergency Department Resuscitative Endovascular Balloon Occlusion of the Aorta in Trauma Patients With Exsanguinating Hemorrhage: The UK-REBOA Randomized Clinical Trial

Importance

Bleeding is the most common cause of preventable death after trauma.

Objective

To determine the effectiveness of resuscitative endovascular balloon occlusion of the aorta (REBOA) when used in the emergency department along with standard care vs standard care alone on mortality in trauma patients with exsanguinating hemorrhage.

Design, Setting, and Participants

Pragmatic, bayesian, randomized clinical trial conducted at 16 major trauma centers in the UK. Patients aged 16 years or older with exsanguinating hemorrhage were enrolled between October 2017 and March 2022 and followed up for 90 days.

Intervention

Patients were randomly assigned (1:1 allocation) to a strategy that included REBOA and standard care (n = 46) or standard care alone (n = 44).

Main Outcomes and Measures

The primary outcome was all-cause mortality at 90 days. Ten secondary outcomes included mortality at 6 months, while in the hospital, and within 24 hours, 6 hours, or 3 hours; the need for definitive hemorrhage control procedures; time to commencement of definitive hemorrhage control procedures; complications; length of stay; blood product use; and cause of death.

Results

Of the 90 patients (median age, 41 years [IQR, 31-59 years]; 62 [69%] were male; and the median Injury Severity Score was 41 [IQR, 29-50]) randomized, 89 were included in the primary outcome analysis because 1 patient in the standard care alone group declined to provide consent for continued participation and data collection 4 days after enrollment. At 90 days, 25 of 46 patients (54%) had experienced all-cause mortality in the REBOA and standard care group vs 18 of 43 patients (42%) in the standard care alone group (odds ratio [OR], 1.58 [95% credible interval, 0.72-3.52]; posterior probability of an OR >1 [indicating increased odds of death with REBOA], 86.9%). Among the 10 secondary outcomes, the ORs for mortality and the posterior probabilities of an OR greater than 1 for 6-month, in-hospital, and 24-, 6-, or 3-hour mortality were all increased in the REBOA and standard care group, and the ORs were increased with earlier mortality end points. There were more deaths due to bleeding in the REBOA and standard care group (8 of 25 patients [32%]) than in standard care alone group (3 of 18 patients [17%]), and most occurred within 24 hours.

Conclusions and Relevance

In trauma patients with exsanguinating hemorrhage, a strategy of REBOA and standard care in the emergency department does not reduce, and may increase, mortality compared with standard care alone.

Trial Registration

isrctn.org Identifier: ISRCTN16184981.

Predictors of long-term intraocular pressure control after lens extraction in primary angle closure glaucoma: results from the EAGLE trial

BACKGROUND/AIMS

To assess baseline ocular parameters in the prediction of long-term intraocular pressure (IOP) control after clear lens extraction (CLE) or laser peripheral iridotomy (LPI) in patients with primary angle closure (PAC) disease using data from the Effectiveness of Early Lens Extraction for the treatment of primary angle-closure glaucoma (EAGLE) tria.

METHODS

This study is a secondary analysis of EAGLE data where we define the primary outcome of 'good responders' as those with IOP<21 mm Hg without requiring additional surgery and 'optimal responders' as those who in addition were medication free, at 36-month follow-up. Primary analysis was conducted using a multivariate logistic regression model to assess how randomised interventions and ocular parameters predict treatment response.

RESULTS

A total of 369 patients (182 in CLE arm and 187 in LPI arm) completed the 36-month follow-up examination. After CLE, 90% met our predefined 'good response' criterion compared with 67% in the LPI arm, and 66% met 'optimal response' criterion compared with 18% in the LPI arm, with significantly longer drops/surgery-free survival time (p<0.05 for all). Patients randomised to CLE (OR=10.1 (6.1 to 16.8)), Chinese (OR=2.3 (1.3 to 3.9)), and those who had not previously used glaucoma drops (OR=2.8 (1.6 to 4.8)) were more likely to maintain long-term optimal IOP response over 36 months.

CONCLUSION

Patients with primary angle closure glaucoma/PAC are 10 times more likely to maintain drop-free good IOP control with initial CLE surgery than LPI. Non-Chinese ethnicity, higher baseline IOP and using glaucoma drops prior to randomisation are predictors of worse long-term IOP response.

The effectiveness and cost-effectiveness of resuscitative endovascular balloon occlusion of the aorta (REBOA) for trauma patients with uncontrolled torso haemorrhage: study protocol for a randomised clinical trial (the UK-REBOA trial)

BACKGROUND

Haemorrhage is the most common cause of preventable death after injury. REBOA is a novel technique whereby a percutaneously inserted balloon is deployed in the aorta, providing a relatively quick means of temporarily controlling haemorrhage and augmenting cerebral and coronary perfusion, until definitive control of haemorrhage can be attained. The aim of the UK-REBOA trial is to establish the clinical and cost-effectiveness of a policy of standard major trauma centre treatment plus REBOA, as compared with standard major trauma centre treatment alone, for the management of uncontrolled torso haemorrhage caused by injury.

METHODS

Pragmatic, Bayesian, group-sequential, randomised controlled trial, performed in 16 major trauma centres in England. We aim to randomise 120 injured patients with suspected exsanguinating haemorrhage to either standard major trauma centre care plus REBOA or standard major trauma centre care alone. The primary clinical outcome is 90-day mortality. Secondary clinical outcomes include 3-h, 6-h, and 24-h mortality; in-hospital mortality; 6-month mortality; length of stay (in hospital and intensive care unit); 24-h blood product use; need for haemorrhage control procedure (operation or angioembolisation); and time to commencement of haemorrhage control procedure (REBOA, operation, or angioembolisation). The primary economic outcome is lifetime incremental cost per QALY gained, from a health and personal social services perspective.

DISCUSSION

This study, which is the first to randomly allocate patients to treatment with REBOA or standard care, will contribute high-level evidence on the clinical and cost-effectiveness of REBOA in the management of trauma patients with exsanguinating haemorrhage and will provide important data on the feasibility of implementation of REBOA into mainstream clinical practice.

TRIAL REGISTRATION

ISRCTN16184981.

Behavioural optimisation to address trial conduct challenges: case study in the UK-REBOA trial

BACKGROUND

Clinical trials comprise multiple processes at various stages of the trial lifecycle. These processes often involve complex behaviours such as recruiting vulnerable patient populations and clinicians having to deliver complex trial interventions successfully. Few studies have utilised a behavioural framework to assess challenges and develop strategies for effective trial recruitment and delivery of trial interventions. This study reports the application of an innovative methodological approach to understand core trial processes, namely recruitment and intervention delivery, using a behavioural science approach to develop strategies designed to mitigate trial process problems.

METHODS

The UK-REBOA trial aims to evaluate the clinical and cost-effectiveness of resuscitative endovascular balloon occlusion of the aorta (a novel intervention) in injured patients with exsanguinating haemorrhage. A behavioural investigation ('diagnosis') was conducted using theory-informed (Theoretical Domains Framework, TDF) semi-structured interviews with site staff from the UK-REBOA trial to examine trial processes which could be improved in relation to trial recruitment and delivery of the intervention. Interviews were analysed using the TDF to identify influences on behaviour, which were then mapped to techniques for behaviour change and developed into potential solutions.

RESULTS

The behavioural diagnosis of the challenges experienced during trial processes highlighted factors relevant to a range of TDF domains: Skills, Environmental context and resources, Beliefs about capabilities, Beliefs about consequences, Social influences, and Memory, attention, and decision-making processes. Within the solution development phase, we identified 24 suitable behaviour change techniques that were developed into proposed solutions to target reported process problems with the aim of changing behaviour to improve recruitment and/or intervention delivery. Proposed solutions included targeted changes to trial training content, suggestions to restructure the environment (e.g. reinforced the purpose of the trial with information about the social and environmental consequences) and other strategies to reduce barriers to recruitment and intervention delivery.

CONCLUSIONS

This study demonstrates the feasibility of applying a behavioural approach to investigate ('diagnose') behavioural trial process problems and subsequently develop and implement targeted solutions ('treatment') in an active trauma trial. Understanding the factors that affected behaviour, attitudes and beliefs in this trauma trial allowed us to implement theoretically informed, evidence-based solutions designed to enhance trial practices.

TRIAL REGISTRATION

ISRCTN 16,184,981.

Clinical trial management: a profession in crisis?

Clinical trial managers play a vital role in the design and conduct of clinical trials in the UK. There is a current recruitment and retention crisis for this specialist role due to a complex set of factors, most likely to have come to a head due to the COVID-19 pandemic. Academic clinical trial units and departments are struggling to recruit trial managers to vacant positions, and multiple influences are affecting the retention of this highly skilled workforce. Without tackling this issue, we face major challenges in the delivery on the Department of Health and Social Care's Future of UK Clinical Research Delivery implementation plan. This article, led by a leading network of and for UK Trial Managers, presents some of the issues and ways in which national stakeholders may be able to address this.

Early lens extraction with intraocular lens implantation for the treatment of primary angle closure glaucoma: an economic evaluation based on data from the EAGLE trial

OBJECTIVE

To investigate the cost-effectiveness of early lens extraction with intraocular lens implantation for the treatment of primary angle closure glaucoma (PACG) compared to standard care.

DESIGN

Cost-effectiveness analysis alongside a multicentre pragmatic two-arm randomised controlled trial. Patients were followed-up for 36 months, and data on health service usage and health state utility were collected and analysed within the trial time horizon. A Markov model was developed to extrapolate the results over a 5-year and 10-year time horizon.

SETTING

22 hospital eye services in the UK.

POPULATION

Males and females aged 50 years or over with newly diagnosed PACG or primary angle closure (PAC).

INTERVENTIONS

Lens extraction compared to standard care (ie, laser iridotomy followed by medical therapy and glaucoma surgery).

OUTCOME MEASURES

Costs of primary and secondary healthcare usage (UK NHS perspective), quality-adjusted life years (QALYs) and the incremental cost-effectiveness ratio (ICER) for lens extraction versus standard care.

RESULTS

The mean age of participants was 67.5 (8.42), 57.5% were women, 44.6% had both eyes eligible, 1.4% were of Asian ethnicity and 35.4% had PAC. The mean health service costs were higher in patients randomised to lens extraction: £2467 vs £1486. The mean adjusted QALYs were also higher with early lens extraction: 2.602 vs 2.533. The ICER for lens extraction versus standard care was £14 284 per QALY gained at three years. Modelling suggests that the ICER may drop to £7090 per QALY gained by 5 years and that lens extraction may be cost saving by 10 years. Our results are generally robust to changes in the key input parameters and assumptions.

CONCLUSIONS

We find that lens extraction has a 67-89% chance of being cost-effective at 3 years and that it may be cost saving by 10 years.

TRIAL REGISTRATION NUMBER

ISRCTN44464607; Results.

Visual sign phonology: insights into human reading and language from a natural soundless phonology

Among the most prevailing assumptions in science and society about the human reading process is that sound and sound-based phonology are critical to young readers. The child's sound-to-letter decoding is viewed as universal and vital to deriving meaning from print. We offer a different view. The crucial link for early reading success is not between segmental sounds and print. Instead the human brain's capacity to segment, categorize, and discern linguistic patterning makes possible the capacity to segment all languages. This biological process includes the segmentation of languages on the hands in signed languages. Exposure to natural sign language in early life equally affords the child's discovery of silent segmental units in visual sign phonology (VSP) that can also facilitate segmental decoding of print. We consider powerful biological evidence about the brain, how it builds sound and sign phonology, and why sound and sign phonology are equally important in language learning and reading. We offer a testable theoretical account, reading model, and predictions about how VSP can facilitate segmentation and mapping between print and meaning. We explain how VSP can be a powerful facilitator of all children's reading success (deaf and hearing)-an account with profound transformative impact on learning to read in deaf children with different language backgrounds. The existence of VSP has important implications for understanding core properties of all human language and reading, challenges assumptions about language and reading as being tied to sound, and provides novel insight into a remarkable biological equivalence in signed and spoken languages. WIREs Cogn Sci 2016, 7:366-381. doi: 10.1002/wcs.1404 For further resources related to this article, please visit the WIREs website.

Conservative treatment for urinary incontinence in Men After Prostate Surgery (MAPS): two parallel randomised controlled trials

OBJECTIVE

To determine the clinical effectiveness and cost-effectiveness of active conservative treatment, compared with standard management, in regaining urinary continence at 12 months in men with urinary incontinence at 6 weeks after a radical prostatectomy or a transurethral resection of the prostate (TURP).

BACKGROUND

Urinary incontinence after radical prostate surgery is common immediately after surgery, although the chance of incontinence is less after TURP than following radical prostatectomy.

DESIGN

Two multicentre, UK, parallel randomised controlled trials (RCTs) comparing active conservative treatment [pelvic floor muscle training (PFMT) delivered by a specialist continence physiotherapist or a specialist continence nurse] with standard management in men after radial prostatectomy and TURP.

SETTING

Men having prostate surgery were identified in 34 centres across the UK. If they had urinary incontinence, they were invited to enroll in the RCT.

PARTICIPANTS

Men with urinary incontinence at 6 weeks after prostate surgery were eligible to be randomised if they consented and were able to comply with the intervention.

INTERVENTIONS

Eligible men were randomised to attend four sessions with a therapist over a 3-month period. The therapists provided standardised PFMT and bladder training for male urinary incontinence and erectile dysfunction. The control group continued with standard management.

MAIN OUTCOME MEASURES

The primary outcome of clinical effectiveness was urinary incontinence at 12 months after randomisation, and the primary measure of cost-effectiveness was incremental cost per quality-adjusted life-year (QALY). Outcome data were collected by postal questionnaires at 3, 6, 9 and 12 months.

RESULTS

Within the radical group (n = 411), 92% of the men in the intervention group attended at least one therapy visit and were more likely than those in the control group to be carrying out any PFMT at 12 months {adjusted risk ratio (RR) 1.30 [95% confidence interval (CI) 1.09 to 1.53]}. The absolute risk difference in urinary incontinence rates at 12 months between the intervention (75.5%) and control (77.4%) groups was -1.9% (95% CI -10% to 6%). NHS costs were higher in the intervention group [£ 181.02 (95% CI £ 107 to £ 255)] but there was no evidence of a difference in societal costs, and QALYs were virtually identical for both groups. Within the TURP group (n = 442), over 85% of men in the intervention group attended at least one therapy visit and were more likely to be carrying out any PFMT at 12 months after randomisation [adjusted RR 3.20 (95% CI 2.37 to 4.32)]. The absolute risk difference in urinary incontinence rates at 12 months between the intervention (64.9%) and control (61.5%) groups for the unadjusted intention-to-treat analysis was 3.4% (95% CI -6% to 13%). NHS costs [£ 209 (95% CI £ 147 to £ 271)] and societal costs [£ 420 (95% CI £ 54 to £ 785)] were statistically significantly higher in the intervention group but QALYs were virtually identical.

CONCLUSIONS

The provision of one-to-one conservative physical therapy for men with urinary incontinence after prostate surgery is unlikely to be effective or cost-effective compared with standard care that includes the provision of information about conducting PFMT. Future work should include research into the value of different surgical options in controlling urinary incontinence.

Urinary incontinence in men after formal one-to-one pelvic-floor muscle training following radical prostatectomy or transurethral resection of the prostate (MAPS): two parallel randomised controlled trials

BACKGROUND

Urinary incontinence is common immediately after prostate surgery. Men are often advised to do pelvic-floor exercises, but evidence to support this is inconclusive. Our aim was to establish if formal one-to-one pelvic floor muscle training reduces incontinence.

METHODS

We undertook two randomised trials in men in the UK who were incontinent 6 weeks after radical prostatectomy (trial 1) or transurethral resection of the prostate (TURP; trial 2) to compare four sessions with a therapist over 3 months with standard care and lifestyle advice only. Randomisation was by remote computer allocation. Our primary endpoints, collected via postal questionnaires, were participants' reports of urinary incontinence and incremental cost per quality-adjusted life year (QALY) after 12 months. Group assignment was masked from outcome assessors, but this masking was not possible for participants or caregivers. We used intention-to-treat analyses to compare the primary outcome at 12 months. This study is registered, number ISRCTN87696430.

FINDINGS

In the intervention group in trial 1, the rate of urinary incontinence at 12 months (148 [76%] of 196) was not significantly different from the control group (151 [77%] of 195; absolute risk difference [RD] -1·9%, 95% CI -10 to 6). In trial 2, the difference in the rate of urinary incontinence at 12 months (126 [65%] of 194) from the control group was not significant (125 [62%] of 203; RD 3·4%, 95% CI -6 to 13). Adjusting for minimisation factors or doing treatment-received analyses did not change these results in either trial. No adverse effects were reported. In both trials, the intervention resulted in higher mean costs per patient (£180 and £209 respectively) but we did not identify evidence of an economically important difference in QALYs (0·002 [95% CI -0·027 to 0·023] and -0·00003 [-0·026 to 0·026]).

INTERPRETATION

In settings where information about pelvic-floor exercise is widely available, one-to-one conservative physical therapy for men who are incontinent after prostate surgery is unlikely to be effective or cost effective. The high rates of persisting incontinence after 12 months suggest a substantial unrecognised and unmet need for management in these men.

FUNDING

National Institute of Health Research, Health Technology Assessment (NIHR HTA) Programme.

The effectiveness of early lens extraction with intraocular lens implantation for the treatment of primary angle-closure glaucoma (EAGLE): study protocol for a randomized controlled trial

BACKGROUND

Glaucoma is the leading cause of irreversible blindness. Although primary open-angle glaucoma is more common, primary angle-closure glaucoma (PACG) is more likely to result in irreversible blindness. By 2020, 5·3 million people worldwide will be blind because of PACG. The current standard care for PACG is a stepped approach of a combination of laser iridotomy surgery (to open the drainage angle) and medical treatment (to reduce intraocular pressure). If these treatments fail, glaucoma surgery (eg, trabeculectomy) is indicated. It has been proposed that, because the lens of the eye plays a major role in the mechanisms leading to PACG, early clear lens extraction will improve glaucoma control by opening the drainage angle. This procedure might reduce the need for drugs and glaucoma surgery, maintain good visual acuity, and improve quality of life compared with standard care.EAGLE aims to evaluate whether early lens extraction improves patient-reported, clinical outcomes, and cost-effectiveness, compared with standard care.

METHODS/DESIGN

EAGLE is a multicentre pragmatic randomized trial. All people presenting to the recruitment centres in the UK and east Asia with newly diagnosed PACG and who are at least 50 years old are eligible.The primary outcomes are EQ-5D, intraocular pressure, and incremental cost per quality adjusted life year (QALY) gained. Other outcomes are: vision and glaucoma-specific patient-reported outcomes, visual acuity, visual field, angle closure, number of medications, additional surgery (e.g., trabeculectomy), costs to the health services and patients, and adverse events.A single main analysis will be done at the end of the trial, after three years of follow-up. The analysis will be based on all participants as randomized (intention to treat). 400 participants (200 in each group) will be recruited, to have 90% power at 5% significance level to detect a difference in EQ-5D score between the two groups of 0·05, and a mean difference in intraocular pressure of 1·75 mm Hg. The study will have 80% power to detect a difference of 15% in the glaucoma surgery rate.

TRIAL REGISTRATION

ISRCTN44464607.

After-effects reported by women following colposcopy, cervical biopsies and LLETZ: results from the TOMBOLA trial

OBJECTIVE

Few studies have investigated physical after-effects of colposcopy. We compared post-colposcopy self-reported pain, bleeding, discharge and menstrual changes in women who underwent: colposcopic examination only; cervical punch biopsies; and large loop excision of the transformation zone (LLETZ).

DESIGN

Observational study nested within a randomised controlled trial.

SETTING

Grampian, Tayside and Nottingham.

POPULATION

Nine hundred-and-twenty-nine women, aged 20-59, with low-grade cytology, who had completed their initial colposcopic management.

METHODS

Women completed questionnaires on after-effects at approximately 6-weeks, and on menstruation at 4-months, post-colposcopy.

MAIN OUTCOME MEASURES

Frequency of pain, bleeding, discharge; changes to first menstrual period post-colposcopy.

RESULTS

Seven hundred-and-fifty-one women (80%) completed the 6-week questionnaire. Of women who had only a colposcopic examination, 14-18% reported pain, bleeding or discharge. Around half of women who had biopsies only and two-thirds treated by LLETZ reported pain or discharge (biopsies: 53% pain, 46% discharge; LLETZ: 67% pain, 63% discharge). The frequency of bleeding was similar in the biopsy (79%) and LLETZ groups (87%). Women treated by LLETZ reported bleeding and discharge of significantly longer duration than other women. The duration of pain was similar across management groups. Forty-three percent of women managed by biopsies and 71% managed by LLETZ reported some change to their first period post-colposcopy, as did 29% who only had a colposcopic examination.

CONCLUSIONS

Cervical punch biopsies and, especially, LLETZ carry a substantial risk of after-effects. After-effects are also reported by women managed solely by colposcopic examination. Ensuring that women are fully informed about after-effects may help to alleviate anxiety and provide reassurance, thereby minimising the harms of screening.

Radiation induced lung injury in survivors of childhood cancer

20017

Background: The purpose of this study was to examine survivors of childhood cancer, treated with whole lung irradiation (WLI), for signs of pulmonary insufficiency and to correlate pulmonary function test (PFT) results to symptoms of pulmonary dysfunction as detected using the St. George’s Respiratory Questionnaire (SGRQ). Methods: A cross-sectional study was conducted on eligible patients (>2 years from WLI and <18 years at time of diagnosis) who are followed in our institution’s cancer survivor program. Participating patients had a history and physical examination and PFTs performed pre and post bronchodilator challenge. Patients (or their guardians) also completed the SGRQ. The SGRQ, validated for patients 17 to 80 years, generates four values that define respiratory dysfunction: a Symptoms score, an Activity Score, an Impact score, and a Total score. Results: Twenty eligible patients were identified, 12 of whom consented to participate in this study (11 Wilms, 1 Ewing sarcoma). The median current age was 18.4 years (7.5 to 43 years; n=6 < 14 yrs), while patients received WLI (1,200 cGy n=10, 1500 cGy n=2) at a median age of 4.4 years of age (1.7 to 8.7 years). The median time from radiation therapy was 12.6 years (4.7 to 34.3 years). All patients denied smoking, 4 had a history of asthma and all had a normal lung exam. Ten patients had PFTs, 5 of whom (4/5 adults and 1/5 children) had a restrictive pattern noted by PFTs. One further patient (7.5 yrs of age) had a total lung volume 70% predicted but a forced vital capacity 86% predicted. In the pediatric patients (<14 years currently) the FEF 25–75 (4/5) and SGaw (5/5) were increased following treatment with bronchodilator. Twelve participants completed the SGRQ, 4 had elevated total scores (22, 32, 37 and 64). 1 patient with echocardiographic evidence of a dilated cardiomyopathy had an elevated total score but normal symptom score. One patient with a recorded acute pneumonitis after WLI, now 18 years later had normal PFTs and normal SGRQ scores. No correlation was seen between PFT results and SGRQ scores. Conclusions: A restrictive lung function pattern is more common at a later age following WLI in childhood. Mid-expiratory flow and airway conductance following bronchodilator were increased in children. The functional significance of these findings requires further study.

No significant financial relationships to disclose.

Insulinoma induced hypoglycaemia in a Jamaican patient

Herein reported is the case of a young woman who had hyperinsulinaemic hypoglycaemia which was biochemically consistent with an insulinoma. Initial imaging was negative and definitive treatment was delayed until repeat imaging localized the tumour several years later. This case demonstrates the importance of clinical judgment and biochemical testing in the diagnosis of insulinoma despite negative imaging.

Enclosing a pen with a postal questionnaire can significantly increase the response rate

BACKGROUND AND OBJECTIVES

It is important to maximize response rates to postal questionnaires. We compared the impact of three low-cost interventions on response rates.

METHODS

A 2 x 2 x 2 factorial trial was conducted, nested within TOMBOLA (Trial Of Management of Borderline and Other Low-grade Abnormal smears). Three interventions were evaluated: (1) enclosing a TOMBOLA-branded pen with the questionnaire (as opposed to no pen); (2) sending the questionnaires by first class post (as opposed to second class); and (3) enclosing a preaddressed return envelope on which there was a second class postage stamp (rather than a freepost business-reply envelope). Nine hundred thirty women, aged 20-59 years, due to receive a TOMBOLA psychosocial questionnaire by post during June-August 2003 were randomized.

RESULTS

Enclosing a pen resulted in a statistically significant 7.0% increase in the cumulative proportion of questionnaires returned (from 61.5 to 68.5%; P = .002). The adjusted odds of response was significantly raised (odds ratio [OR] = 1.38, 95% confidence interval [CI] 1.04-1.82). Neither first class post nor providing a stamped envelope had a significant impact on response. There were no interactions between the interventions.

CONCLUSIONS

Enclosing a pen with a questionnaire can significantly increase response. This low-cost strategy was effective against a background of "good practice" with regard to the administration of postal questionnaires.

Who is a generalist? An analysis of whether physicians trained as generalists practice as generalists

Accurate data on the number of generalist physicians are needed to monitor the physician workforce and to plan for future requirements in the changing health care system. This study assessed the relationship between two frequently used definitions of a generalist physician: completion of graduate medical education (GME) in only a generalist discipline and physician's self-report of practicing as a generalist. Data for 4,808 physician graduates from six Pennsylvania medical schools from 1986 to 1991 were analyzed using information from the GME tracking census of the Association of American Medical Colleges and the Physician Masterfile of the American Medical Association. Of 1,291 physicians trained in a generalist discipline, 1,205 (93%) reported practicing as generalists. Conversely, of the 3,517 not trained in a generalist discipline, 3,358 (95%) were not practicing as generalists. These results indicate GME training is a valid predictor of self-reported practice and provide baseline data to monitor future changes.

Implantable venous access devices in children with hemophilia: a report of low infection rates

OBJECTIVE

The objective of this study was to define the efficacy and complications of implantable venous access devices (IVADs) in children with hemophilia.

STUDY DESIGN

Records were reviewed on all patients with congenital blood coagulation disorders monitored at two children's hospitals in whom one or more central venous catheters had been placed.

RESULTS

Since 1989 external and implantable central venous catheters have been inserted to enhance venous access for regular factor concentrate infusion in 45 patients with hemophilia ranging in age from 8 months to 19.5 years (median 7.4 years); 37 patients had factor VIII deficiency and 8 factor IX deficiency. Hemorrhagic complications of catheter placement were infrequent and minor. In the 41 patients having one or more IVADs in place for a median of 31 months, only six episodes of bacteremia occurred in 5 patients during 44,070 days of follow-up. The overall rate of bacteremia complicating IVADs in these patients was 0.14 episodes per 1000 catheter days. Other catheter-related complications were uncommon. Catheters are still in place in 33 patients for a median of 32 months.

CONCLUSION

The low risk of infection and other complications associated with the use of IVADs makes the use of these devices attractive in the treatment of patients with hemophilia who require frequent venous access for factor concentrate infusions.

Similar incidence of K-ras mutations in lung carcinomas of FVB/N mice and FVB/N mice carrying a mutant p53 transgene

Mutated p53 genes are capable of complementing activated ras genes in the transformation of primary rat embryo fibroblasts in vitro. Mutations in both genes have also been found in several human cancers, including lung carcinomas. We generated transgenic mice containing a p53 construct with a missense mutation in exon 5 (ala135val) to study the role of p53 mutations in lung tumorigenesis, and to facilitate identification of other genetic events that might complement p53 mutations in mouse lung carcinogenesis. The p53 transgenic lines exhibited a higher frequency of lethal lung tumors than the parental FVB/N strain. We examined the spontaneously-arising lung carcinomas from mice expressing the mutated p53 transgene for K-ras mutations using single-stranded conformation polymorphism (SSCP) and/or direct sequencing approaches. Fifteen of 29 (52%) carcinomas contained mutations in the K-ras oncogene. Six of 15 of the K-ras mutations were in codon 61 and 9/15 were in codon 12. Subsequent analysis of spontaneous lung carcinomas from mice of the FVB/N parental strain showed that 9/12 (75%) carcinomas examined contained K-ras mutations. Two of these were in codon 12, one in codon 13, and 6 were in codon 61. These results demonstrate that the frequency of ras mutations does not differ between the p53 FVB/N transgenic mice and their parental FVB/N strain but suggest that a high frequency of mutations K-ras can be correlated with lung tumorigenesis in both groups of mice.

Genetic alterations of p53 and ras genes in 1,3-butadiene- and 2',3'-dideoxycytidine-induced lymphomas

Mutations of p53 and ras genes were analyzed in 40 and 31 1,3-butadiene (BD)-induced lymphomas of B6C3F1 mice (BLFs), respectively, and in 63 2',3'-dideoxycytidine-induced lymphomas, which were collected from B6C3F1 (n = 16) or NIH Swiss mice (DLSs; n = 47). The frequencies of K- and N-ras mutations in BLFs (32 and 13%, respectively) were higher than those in DLSs (13 and 2%, respectively). Seven of 10 K-ras-mutated BLFs contained codon 13 CGC mutations, whereas no mutation in K-ras codon 13 was detected in DLSs, suggesting that the codon 13 CGC mutation is specific for BD exposure. Interestingly, 8 of 13 BLFs with ras mutations were from low-dose (< or = 200 ppm) or stop-exposure (26 weeks) groups. These results suggest that ras mutations play an important role in the development of BD-induced lymphoma and may represent an early event. Analysis of genetic alterations in exons 5-8 of the p53 gene revealed mutations in seven of the BLFs and three of the DLSs. All seven BLFs carrying p53 mutations were collected from the high-dose (625 ppm) continuous exposure group, which might indicate that p53 is involved in the progression of BD-induced lymphoma and in late stage of lymphomagenesis. Mutations in ras and p53 genes are relatively infrequent in 2',3'-dideoxycytidine-induced lymphomas, suggesting that other genes must be involved.

Allelotype analysis of 2',3'-dideoxycytidine- and 1,3-butadiene-induced lymphomas in B6C3F1 mice

To identify potential tumor suppressor genes involved in lymphoma development, we generated allelotypes of 16 2',3'-dideoxycytidine (ddC and 31 1,3-butadiene (BD)-induced lymphomas from C57BL/6 x C3H/He F1 (hereafter called B6C3F1) mice. Two or more anonymous simple sequence length polymorphisms per autosome were examined for loss of heterozygosity (LOH). Allelic losses throughout the genome were generally infrequent, except for markers on chromosome 2, 4, 11 and 12. The highest frequency of allelic losses was observed on chromosome 12, with 38 and 39% in ddC and BD-induced lymphomas, respectively. The most prevalent LOH was localized to the distal region bounded by markers D12Mit263 and D12Nds2. No known tumor suppressor genes have been mapped to this region, and no obvious candidates could be identified, suggesting the presence of novel suppressor gene(s). LOH on chromosome 2 was observed in 31% of ddC-induced lymphomas but in only 3% (1/31) of BD-induced lymphomas, suggesting a ddC-specific genetic effect. Detailed analysis localized a potential tumor suppressor gene residing on the distal region of chromosome 2, between markers D2Mit147 and D2Mit148. Twenty-five % of ddC-induced and 23% of BD-induced lymphomas showed LOH on chromosome 4, and two discrete regions were identified. One of the regions includes the IFN gene cluster and is syntenic to human chromosome 9p2l-22. Candidate tumor suppressor genes, Mts1 (multiple tumor suppressor 1) and Mts2 have been mapped to this region. The second region is located on the distal part of chromosome 4, which is homologous to human chromosome 1p35-36, a region that is frequently deleted in various types of human tumors. Finally, 19% of ddC-induced and 29% of BD-induced lymphomas revealed LOH on chromosome 11 at the Acrb locus, which lies within 1 cM of p53, suggesting that the p53 tumor suppressor gene also plays a role in lymphomagenesis. These results suggest that multiple potential suppressor loci contribute to lymphoma development in B6C3F1 mice.

BRCA2 mutations in primary breast and ovarian cancers

The second hereditary breast cancer gene, BRCA2, was recently isolated. Germline mutations of this gene predispose carriers to breast cancer, and, to a lesser extent, ovarian cancer. Loss of heterozygosity (LOH) at the BRCA2 locus has been observed in 30-40% of sporadic breast and ovarian tumours, implying that BRCA2 may act as a tumour suppressor gene in a proportion of sporadic cases. To define the role of BRCA2 in sporadic breast and ovarian cancer, we screened the entire gene for mutations using a combination of techniques in 70 primary breast carcinomas and in 55 primary epithelial ovarian carcinomas. Our analysis revealed alterations in 2/70 breast tumours and none of the ovarian carcinomas. One alteration found in the breast cancers was a 2-basepair (bp) deletion (4710delAG) which was subsequently shown to be a germline mutation, the other was a somatic missense mutation (Asp3095Glu) of unknown significance. Our results suggest that BRCA2 is a very infrequent target for somatic inactivation in breast and ovarian carcinomas, similar to the results obtained for BRCA1.

Mutation analysis of the BRCA2 gene in 49 site-specific breast cancer families

The hereditary breast cancer gene BRCA2 was recently cloned and is believed to account for almost half of site-specific breast cancer families and the majority of male breast cancer families. We screened 49 site-specific breast cancer families for mutations in the BRCA2 gene using single strand conformation analysis (SSCA) followed by direct sequencing. We found mutations in eight families, including all four families with male breast cancer. The eight mutations were small deletions with the exception of a single nonsense mutation, an all were predicted to interrupt the BRCA2 coding sequence and to lead to a truncated protein product. Other factors which predicted the presence of a BRCA2 mutation included a case of breast cancer diagnosed at age 35 or below (P = 0.01) and a family history of pancreatic cancer (P = 0.03). Two mutations were seen twice, including a 8535delAG, which was detected in two French Canadian families. Our results suggest the possibility that the proportion of site-specific breast cancer families attributable to BRCA2 may be overestimated.

Isolation of the mouse homologue of BRCA1 and genetic mapping to mouse chromosome 11

The BRCA1 gene is in large part responsible for hereditary human breast and ovarian cancer. Here we report the isolation of the murine Brca1 homologue cDNA clones. In addition, we identified genomic P1 clones that contain most, if not all, of the mouse Brca1 locus. DNA sequence analysis revealed that the mouse and human coding regions are 75% identical at the nucleotide level while the predicted amino acid identity is only 58%. A DNA sequence variant in the Brca1 locus was identified and used to map this gene on a (Mus m. musculus Czech II x C57BL/KsJ)F1 x C57BL/KsJ intersubspecific backcross to distal mouse chromosome 11. The mapping of this gene to a region highly syntenic with human chromosome 17, coupled with Southern and Northern analyses, confirms that we isolated the murine Brca1 homologue rather than a related RING finger gene. The isolation of the mouse Brca1 homologue will facilitate the creation of mouse models for germline BRCA1 defects.

BRCA1 mutations in primary breast and ovarian carcinomas

Loss of heterozygosity data from familial tumors suggest that BRCA1, a gene that confers susceptibility to ovarian and early-onset breast cancer, encodes a tumor suppressor. The BRCA1 region is also subject to allelic loss in sporadic breast and ovarian cancers, an indication that BRCA1 mutations may occur somatically in these tumors. The BRCA1 coding region was examined for mutations in primary breast and ovarian tumors that show allele loss at the BRCA1 locus. Mutations were detected in 3 of 32 breast and 1 of 12 ovarian carcinomas; all four mutations were germline alterations and occurred in early-onset cancers. These results suggest that mutation of BRCA1 may not be critical in the development of the majority of breast and ovarian cancers that arise in the absence of a mutant germline allele.

A strong candidate for the breast and ovarian cancer susceptibility gene BRCA1

A strong candidate for the 17q-linked BRCA1 gene, which influences susceptibility to breast and ovarian cancer, has been identified by positional cloning methods. Probable predisposing mutations have been detected in five of eight kindreds presumed to segregate BRCA1 susceptibility alleles. The mutations include an 11-base pair deletion, a 1-base pair insertion, a stop codon, a missense substitution, and an inferred regulatory mutation. The BRCA1 gene is expressed in numerous tissues, including breast and ovary, and encodes a predicted protein of 1863 amino acids. This protein contains a zinc finger domain in its amino-terminal region, but is otherwise unrelated to previously described proteins. Identification of BRCA1 should facilitate early diagnosis of breast and ovarian cancer susceptibility in some individuals as well as a better understanding of breast cancer biology.

Localization of the VHR phosphatase gene and its analysis as a candidate for BRCA1

The VH1-related human protein (VHR) gene was localized to human chromosome 17q21 in a region thought to contain the BRCA1 locus, a locus that confers susceptibility to breast and ovarian cancer. VHR encodes a phosphatase with dual specificity for tyrosine and serine residues. Thus it is a plausible candidate for a tumor suppressor gene such as BRCA1. To test this possibility, the VHR coding sequence was screened in individuals with familial breast cancer and in sporadic breast tumor and breast cancer cell lines. No mutations were detected, suggesting that the VHR gene is not BRCA1.

Isolation of a diverged homeobox gene, MOX1, from the BRCA1 region on 17q21 by solution hybrid capture

Using the technique of solution hybridization coupled with magnetic bead capture, we have isolated a novel homeobox-containing gene from the BRCA1 region of 17q21. This gene is the human homologue of the mouse Mox1 gene previously localized to a syntenic region of mouse chromosome 11. Multiple overlapping cDNAs of human MOX1 were identified using both a cosmid and a P1 genomic clone containing the microsatellite markers D17S750 and D17S858 which map within the BRCA1 region defined by D17S776 and D17S78. MOX1 expression was observed in a variety of normal tissues examined, including breast and ovary. Given that the gene contains a homeobox domain and has the potential to regulate growth and differentiation, MOX1 represents an attractive candidate for the BRCA1 gene. This possibility was investigated in a series of BRCA1 kindreds and primary sporadic breast tumors. No evidence for mutation was found in the coding sequence, making it unlikely that MOX1 is the BRCA1 gene. However, the widespread expression of MOX1 in non-embryonal tissues suggests a role in normal cell biology which warrants further study.

Non-insulin-mediated glucose disappearance in subjects with IDDM. Discordance between experimental results and minimal model analysis

Both insulin and glucose contribute to the regulation of glucose metabolism in vivo. We directly measured the ability of glucose per se to promote glucose disposal in subjects with insulin-dependent diabetes mellitus (IDDM). We compared our results with predictions of the minimal model of glucose metabolism. To identify minimal model parameters, a frequently sampled intravenous glucose tolerance test (FSIVGTT) was administered to each subject while they were connected to a Biostator (a device that monitors blood glucose and gives insulin to mimic normal insulin secretion). Data from this test reflected normal glucose tolerance and were in excellent agreement with minimal model predictions. The FSIVGTT was then repeated without the Biostator in the same diabetic subjects in order to directly measure the effect of glucose per se to promote glucose disposal in the absence of an incremental insulin effect (a basal insulin drip was maintained). To compare these results with minimal model predictions, the equations describing glucose disappearance in the absence of an incremental insulin effect were solved using parameters identified from the Biostator experiment. The glucose disappearance measured in the absence of an incremental insulin response was much slower than the minimal model predictions. Thus, the minimal model appears to overestimate the effect of glucose per se on glucose uptake and underestimate the contribution of incremental insulin.

Allelotyping of butadiene-induced lung and mammary adenocarcinomas of B6C3F1 mice: frequent losses of heterozygosity in regions homologous to human tumor-suppressor genes

To identify the potential involvement of tumor-suppressor gene inactivation during neoplastic development in B6C3F1 mice, genetic losses were determined from allelotypes of butadiene-induced lung and mammary adenocarcinomas. By using length polymorphisms in restriction fragments and simple sequence repeats, or "microsatellites," markers on each autosome were analyzed for allele losses in tumor DNAs. Losses of heterozygosity on chromosome 11 were observed at several loci surrounding the p53 tumor-suppressor gene (Trp53) in 12 of 17 mammary tumors and 2 of 8 lung tumors. Although most of these alterations appeared to result from nondisjunction, at least two examples of somatic recombination or deletion were also observed. Southern analysis revealed a homozygous deletion of the remaining Trp53 allele of one of these mammary tumors. Losses of heterozygosity were also detected at the Rb-1 tumor-suppressor gene in 7 of 17 mammary tumors and 1 lung tumor. Finally, frequent allele losses were observed on chromosome 4 in lung tumors. Analysis of nine chromosome 4 loci defined an interstitial deletion containing the Ifa gene cluster in one of the lung tumors. A tumor-suppressor gene was previously mapped to this region of chromosome 4 in studies with somatic cell hybrids. In addition, homozygous deletions have been reported in a homologous region of human chromosome 9p for acute lymphocytic leukemias, glioblastomas, melanomas, and lung carcinomas. These findings suggest that the inactivation of tumor-suppressor genes including Trp53, Rb-1, and an unidentified gene on chromosome 4 plays a significant role during carcinogenesis in mice.

Mutation analysis of the THRA1 gene in breast cancer: deletion/fusion of the gene to a novel sequence on 17q in the BT474 cell line

We have previously described a common region of deletion and allele loss on chromosome 17q in sporadic breast cancers that is likely to contain a tumor suppressor gene. The region, mapped to 17q12-q21, was bordered by D17S250 and D17S579 on the centromeric and telomeric sides, respectively. This deletion region overlaps the BRCA1 locus, which predisposes to familial breast and ovarian cancer. The most frequent loss of heterozygosity was observed at the thyroid hormone receptor alpha (THRA1) locus. Southern analysis revealed a rearrangement of THRA1 in the BT474 breast cancer cell line. This rearrangement represented a deletion of exons 8-10 of one THRA1 allele that was also coamplified with ERBB2. Northern blots showed two mutant transcripts in BT474 cells. Analysis of the mutant transcripts revealed fusion of the THRA1 exon 7 by splicing to a novel sequence designated BTR for "BT474 transcribed rearrangement." BTR was found to be highly conserved and mapped to 17q. The deletion in BT474 cells spans the entire BRCA1 region. To search for additional mutations in the THRA1 gene, all nine protein-encoding exons of THRA1 were examined for point mutations via single strand conformation analysis in a series of primary breast tumors, breast cancer cell lines, and lymphoblastoid cell lines derived from the youngest affected members of several German breast cancer families. No point mutations were detected, including the unrearranged THRA1 allele in BT474. We have thus excluded THRA1 as a commonly mutated sporadic breast cancer tumor suppressor gene and as the BRCA1 gene.

Infrequent p53 mutations in 7,12-dimethylbenz[a]anthracene-induced mammary tumors in BALB/c and p53 hemizygous mice

We conducted experiments to determine if p53 alterations, which are frequent in human breast cancers, were also common in murine mammary tumors. In 13 mammary tumors from 7,12-dimethylbenz[a]anthracene (DMBA)-treated BALB/c mice were immunohistochemically analyzed for overexpression of p53; p53 protein was not detectable. Three of the tumors were established as cell lines in vitro. p53 protein was rarely detected at passage 4 in these lines but was overexpressed by passage 8 in two of them. The p53 nucleotide sequence was shown to be wild type in one primary mammary tumor and in the two p53-overexpressing cell lines. One cell line that overexpressed p53 in vitro was implanted into BALB/c mice. The resulting tumors retained the wild-type p53 nucleotide sequence but no longer expressed detectable levels of p53 protein, suggesting that the overexpression of wild-type p53 was related to in vitro culture conditions. The effect of DMBA on mammary-tumor development was also tested in mice rendered hemizygous for p53. These mice and wild-type littermate controls had no differences in susceptibility to induction of mammary tumors by oral administration of DMBA. Furthermore, Southern blot hybridization detected no gross alterations in the wild-type p53 allele in mammary tumors from the p53-deficient mice. Point mutation of the wild-type p53 allele was also infrequent in the DMBA-induced mammary tumors from hemizygous p53 mice; it occurred in only one of seven tumors. Thus, the p53 gene is apparently not a primary target for genetic alterations in DMBA-induced mammary tumors. Next, we examined mammary tumors derived from D1 and D2 transplantable hyperplastic alveolar nodule (HAN) outgrowths, which rapidly form tumors containing Ha-ras mutations after DMBA treatment. As ras and p53 mutants can cooperate in transformation, we examined whether D1 and D2 HAN outgrowths have p53 mutations. Unlike in the DMBA-induced primary mammary tumors, nuclear p53 accumulation was observed frequently (10 of 14) in tumors that arose from D1 and D2 HAN outgrowths. Direct sequencing of the entire coding region of the p53 cDNA from six D1 and D2 tumors confirmed that the sequence was wild type. Although wild-type p53 was retained in both DMBA-induced mammary tumors and mammary tumors derived from D1 and D2 preneoplastic outgrowths, wild-type p53 overexpression was detected only in D1 and D2 tumors. Therefore, D1 and D2 tumors appear to arise by a pathway in which p53 expression is altered, whereas DMBA induction affects a different pathway that does not require such alteration.

Detection of frequent allelic loss on proximal chromosome 17q in sporadic breast carcinoma using microsatellite length polymorphisms

Analyses of losses of heterozygosity and linkage studies have implicated a gene(s) on chromosome 17q in the genesis of sporadic and early-onset familial breast carcinomas, respectively. To define the critical region of 17q, we examined DNAs from a series of 20 sporadic breast carcinomas and corresponding blood samples for allelic losses of chromosome 17q using microsatellite length polymorphisms. With these highly informative markers (average heterozygosity, 0.73), we observed frequent deletions of 17q at several loci. We found that D17S250 was deleted in 50% (7 of 14), THRA1 in 79% (11 of 14), D17S579 in 59% (11 of 19), NME1 in 29% (5 of 17), MPO in 36% (4 of 11), and GH in 25% (4 of 16) in the tumor set examined. A common region of deletion was found that was flanked by D17S250 to D15S579. These markers have recently been localized to a 6-cM interval of proximal chromosome 17q in bands 17q11.2-q21 and map within the region of the early-onset familial breast cancer locus, implying that the same gene or genes may be involved in both sporadic and familial breast tumors. Thyroid hormone receptor alpha and retinoic acid receptor alpha are two potential candidate genes in this region.

Lack of effect of vitamin B-6 supplementation on the lipoprotein profile of post-menopausal chronic hemodialysis patients

This study was designed to analyze the effect of vitamin B-6 supplementation on the lipoprotein profile of chronic hemodialysis patients. Individuals on chronic hemodialysis experience an acceleration of atherosclerosis, which is often accompanied by abnormal lipid metabolism. Although total plasma cholesterol is usually normal, high-density-lipoprotein (HDL) cholesterol is often low. Recently, it has been suggested that the development of atherosclerotic lesions in chronic hemodialysis patients may be the result of a decreased plasma concentration of pyridoxal 5'-phosphate (PLP) and concomitant alterations in plasma amino acid and/or lipoprotein profiles. All subjects in this study were supplemented with 0.97 mmol (200 mg) pyridoxine hydrochloride per day for 28 days; then, concentrations of PLP, total cholesterol, and lipoprotein cholesterol fractions were determined in the plasma. No significant difference was noted in PLP concentration between Group 1 (five post-menopausal women with a history of atherosclerosis who were undergoing maintenance hemodialysis therapy) and Group 2 (six subjects who were non-symptomatic). However, both groups had significant increases in PLP concentrations between the pre- and post-supplementation periods (p less than .01). In contrast, there was a statistically significant difference in total plasma cholesterol and very-low-density- and low-density-lipoprotein (VLDL and LDL) cholesterol concentrations between groups, but no significant changes in total cholesterol or VLDL and LDL cholesterol content were found during vitamin B-6 supplementation. No statistically significant differences in HDL, HDL2, and HDL3 cholesterol concentrations were observed between Group 1 and Group 2 subjects or within either group during vitamin B-6 supplementation.

Randomized study of continuous infusion fluorouracil versus fluorouracil plus cisplatin in patients with metastatic colorectal cancer

One hundred twenty-two chemotherapy-naive patients with histologically confirmed colorectal adenocarcinoma were entered into a randomized trial comparing infusional fluorouracil (FU) versus cisplatin (CDDP) and FU. In both groups, patients received continuous infusion FU 1,000 mg/m2/d for 5 consecutive days every 4 weeks. Patients randomized to CDDP/FU also received CDDP 20 mg/m2 intravenous (IV) bolus on days 1 to 5 of each cycle. Patients were comparable in terms of age, performance status, baseline laboratory values, dominant sites of measurable disease, and percent of liver involvement. The partial response rate was significantly greater in patients who received CDDP/FU versus FU alone (25% v 3%, P = .001). Patients who received CDDP/FU experienced significantly greater toxicity compared with FU alone: grades 3 and 4 hematologic toxicity occurred in 22% and 0% of patients, respectively (P = .0001); grades 2 to 4 nausea and vomiting occurred in 80% and 15% of patients, respectively (P = .0001). There were no significant differences in either the duration of response (median, 6 and 4.7 months for CDDP/FU and FU groups, respectively) or survival (median 10, and 12 months, respectively). Compared with infusional FU alone, CDDP/FU provided a significantly greater partial response rate with increased toxicity, but it did not improve overall survival in patients with advanced colorectal carcinoma. Therefore, the use of CDDP/FU as routine therapy for the treatment of colorectal carcinoma cannot be recommended.

Effect of aspartame on plasma amino acid profiles of diabetic patients with chronic renal failure

A randomized, double-blind study was conducted to determine the possible effects of aspartame on the plasma amino acid profiles of 23 diabetic patients with renal failure who were undergoing maintenance hemodialysis. Subjects were given a single dose of 10 mg aspartame/kg (approximately equivalent to 25 packets of Equal [NutraSweet Consumer Products, Inc, Chicago, IL] or the amount of phenylalanine in a 300-mL glass of milk) or a placebo in a crossover study design. Three postdialysis blood samples were drawn just before and 1 and 2 h after aspartame or placebo consumption. After aspartame consumption statistically significant increases in only two amino acids, phenylalanine and tyrosine, were noted at 1 and 2 h when compared with placebo values. The increases in phenylalanine were within the normal postprandial range for healthy subjects; no other increases in essential or nonessential amino acids, except for tyrosine, were detected. This study supports the view that aspartame is safe for diabetic subjects with chronic renal failure.

Reactive perineurial fibroblastic proliferation of the median nerve: MR characteristics

We report a case of fibroblastic proliferation of the median nerve presenting as a focal mass. This report discusses the pathological and magnetic resonance correlations and reviews the differential diagnosis for median nerve masses.