Evaluating the usability of a co-designed interactive web application for cardiac rehabilitation

Funding Acknowledgements

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Novartis

Background/significance

The rapid development of information technology is driving the evolution of choices of modes of delivery of healthcare services. The internet is an extremely powerful tool for accessing information, and communication. However, involvement of patients in the assessment of such an intervention is crucial, and can be achieved through a person-centred approach, utilising a co-design process with the aim to increase intervention usability.

Purpose

To assess the usability of the Country Access to Cardiac Health (CATCH) Web, an interactive web application for cardiac rehabilitation (CR), co-designed with rural and remote Australians, following the co-design development phase.

Methods

The User Experience (UX) Design framework was used to co-design the web portal with CR patients through two rounds of six co-design workshops pre (n=39), and post (n=35). Participants and family members living in rural and remote areas of Australia were invited to participate based on their eligibility for CR as outlined by the National Heart Foundation of Australia. As part of the UX Design Framework the System Usability Scale (SUS) was used to measure objective feedback from participants on the website design. The SUS assesses the three core components of a products usability: effectiveness, efficiency and satisfaction using a 10 question Likert scale. Mean scores were compared between the two rounds of workshops using an independent T-Test. The mean SUS score is categorised into poor to moderate (<68), good (68-80.3) and excellent (>=80.3) and categories were compared between the two rounds of workshops through Chi-Square tests.

Results

The 35 participants in the usability workshops had a mean age of 68.6 (SD 11.2) years and 16 (47%) were female (Table 1). The majority had experienced a myocardial infarction (15, 42.8%) and had hyperlipidemia (17, 50%), heart failure (15, 44%), hypertension (14, 41%), and Type II diabetes (7, 21%). Of these participants 20 (59%) used a smart phone, 18 (58%) had access to the National Broadband Network and 20 (59%) engaged with Facebook. From the first to the second round of workshops, there was an improvement in the mean SUS scores from 66.7 (SD16.8) to 73.6 (SD 21.0); p=0.26. The proportion of participants rating it as good or excellent increased from 48.7 to 65.8%; p=0.11 (Figure1).

Conclusion

The usability testing of the interactive CATCH web application showed an improvement in the SUS rating from poor to moderate in the co-design development phase to good or excellent by most of the participants in the usability testing phase. Usability is closely related to engagement with a digital health intervention. Upcoming evaluation of this intervention will report on clinical outcomes.

Assessing the quality of cardiac rehabilitation programs by measuring adherence to the Australian quality indicators

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Australian National Health and Medical Research Council (NHMRC)

Background

Cardiac rehabilitation (CR) prevents recurrent cardiac events and supports patients’ return to an active and fulfilling lifestyle. Evidence on the efficacy of CR programs is well established, but variability of quality across programs may compromise patient outcomes. Core components, quality indicators (QIs) and accreditation of programs have been introduced internationally to increase program standardisation, quality and outcomes. (1) The Australian Cardiovascular Health and Rehabilitation Association (ACRA) and National Heart Foundation (NHF) recently published 10 QIs for CR, comprising process and outcome indicators that can guide delivery of evidence-based service content (Figure 1). (2)

Purpose

The aim was to assess the performance of CR programs in Australia through their adherence to the measurement of the Australian QIs.

Methods

A cross-sectional survey design with face validity testing was used to formulate questions to evaluate CR program performance based on adherence to 9 of the 10 Australian QIs. Between October 2020- December 2021, all 23 CR programs across country and metropolitan areas of South Australia (SA) participated. In addition, each QI was weighted by an expert group of clinician researchers and a service performance score was calculated out of 16. According to the score quartiles, programs could be categorised across 4 performance levels: Poor (0-4.5), Low (5-8.5), Medium (9-12.5) or High (13-16).

Results

Among the 23 participating CR programs, median wait time from discharge to enrolment (QI-2) was 27 days, (interquartile range 19.0-46.0) and completions of enrolled were 66% (n=1316 /1972). All QIs were measured, but not by all programs. Pre-program QI adherence was higher than post program for depression, medication adherence, health-related quality of life and comprehensive re-assessment (Figure 1). Health-related quality of life (HRQOL) was poorly measured pre and post program (21.7% versus 17.3%). For functional exercise capacity assessment, the six-minute walk test was used by 69.5% of programs. Mean performance score was 11.4 /16 (SD ±0.79). Most (74%) programs were ranked at a medium level of performance, whereas 13% were ranked at low and high levels and none as poor.

Conclusions

A survey of 23 CR programs showed gaps in adherence to measurement of the ACRA/NHF Quality indicators in SA, including re-assessment (QI9), HRQOL (QI-8), medication adherence (QI-6) and exercise capacity (QI-7). Service performance scores were lower than an Australian national audit for each category, with United Kingdom data showing more services in the high and less in the medium category than SA. These data give us a baseline from which to improve CR service quality and outcomes.

Co-designing digital cardiac rehabilitation with patients living in rural and remote australia - the country heart attack prevention project

Funding Acknowledgements

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Co-sponsored National health Medical Partnership Grant

OnBehalf

the country heart attack prevention project

Background/significance. Cardiac rehabilitation (CR) significantly reduces death, reoccurring cardiac events, hospital admissions while improving quality of life. However, it is still poorly attended with participation rates worldwide between 20-50%, worsened for rural and remote patients by the tyranny of distance, work responsibilities and transportation. Web-based CR can provide an alternative, patient centred, flexible delivery option. Co-design with consumers and clinicians is recommended to tailor web-based CR to their needs and preferences as a means of increasing attendance.

Purpose. The objective of this study is to describe how patient-generated data through workshops on desired content and features informs technology and implementation specifications for the patient portal of a CR website.

Methods. UX Design theoretical framework, using a co-design workshop, with thematic analysis, a survey, and the System Usability Scale was used to report outcomes.

Results. Based on the feedback from participants in rural and remote SA, desired content and features were updated for improving user experience. We recruited 27 participants across 4 regional Local health Networks in SA. The median age of participants was 71.0 (IQR 58-78), 14 (51.9%) were female and 27 (100%) had completed a cardiac rehabilitation program. More than half used a smart phone (16; 59.3%) and Facebook (21; 77.8%). Overall usability remains low based on a mean SUS score of 63.4 (SD 21.1), however there was a tendency to usability improving over time.

Conclusion. The co-design process has contributed to the development of the CR website, improving desired content and features. Improved usability scores can be achieved through further incorporating consumer feedback into the development of the CR website.

How the COVID pandemic affected utilisation of cardiac rehabilitation in rural Australia?

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): Caring Futures Institute

Background

Provision of cardiac rehabilitation (CR) was disrupted in 31% of the 155 countries according to the World Health Organisation during the early months of the COVID pandemic. This might have been associated with worsening clinical outcomes and is of particular concern to patients living in rural and remote areas. In Australia, these patients have a higher prevalence of cardiovascular diseases, higher rates of adverse outcomes due to acute myocardial infarction and limited availability to regional services.

Purpose

We aimed to investigate how the COVID affected the delivery of CR services in rural and remote South Australia (SA) during the first wave of the COVID pandemic. 

Methods

CR attendance, completion and waiting times in the pre-COVID period (February-July 2019) was compared to data during the first wave of COVID (February-July 2020) using data from CR services across six regional local health networks recorded in the Country Access to Cardiac Health (CATCH) database.

Results

There were 922 patients (32.2% females; mean age 69.2 years; 36.6% living in areas with high socio-economic disadvantage) referred to CR in the pre-COVID period, and 1032 patients (30.7% females; mean age 68.1 years; 35.7% living in areas with high socio-economic disadvantage) in the COVID period across the six regional areas in South Australia. Acute coronary syndrome was the main reason for referral both pre (251; 27.2%) and during COVID (273; 26.5%). The proportion of CR attendance was higher in the pre (522; 56.6%) compared to the COVID period (431, 41.8%; p < 0.001).  Completion was higher pre (413, 79.1%) compared to during COVID period (205,47.6%) completed CR during the COVID period (p < 0.001). The waiting time was 35 (SD 27) days pre-COVID and 34 (SD 25) days in the COVID period (p = 0.37).

Conclusion

Our data show that attendance and completion of CR programs were significantly reduced during the COVID period in rural and remote Australia. Limited service access during the pandemic and fear to physically attend health services during the period of social and physical restrictions might have contributed to this. Telehealth-delivered CR can provide opportunities to continuity of cardiovascular care and secondary prevention during pandemic restrictions.

Does hospital design impact on patient activity levels and time spent alone?

PURPOSE

The aim of this study was to quantify changes in patients' activity levels, location and people present, within one acute stroke unit (ASU) and one inpatient rehabilitation unit (IRU) with respect to change in hospital design.

METHODS

A prospective observational study using behavioural mapping. We observed participants from 8 am till 5 pm every 10 minutes across two days and compared participant activity (physical, social and cognitive), location and people present pre and post-transition to new units. Built design, staffing levels and models of care were contrasted.

RESULTS

We recruited 73 participants (63% stroke): old-ASU (n = 19); new-ASU (n = 15); old-IRU (n = 19); new-IRU (n = 20). Compared to old, new units had more single rooms, larger floor spaces and higher staffing levels. We found no significant change in participants' activity levels between the old and new ASU. Participants in the new IRU showed increased physical activity (43.4% vs. 54.4%, p = 0.02) but social and cognitive activity remained similar. Participants were more alone (ASU 47.4% vs. 66.7%, p = 0.01; IRU 41.7% vs. 58.3%, p < 0.001), and less often with nursing staff (ASU 17.7% vs. 6.7%, p = 0.04; IRU 18.8% vs. 5.7%, p < 0.001) in new units.

CONCLUSION

Hospital design appears to impact on patients' physical activity. Single rooms may increase isolation and reduce interaction with nursing staff.Implications for rehabilitationDesign of new rehabilitation units needs to consider patients' social engagement with family, friends, other patients and staff in addition to privacy and infection control.A change in built design of rehabilitation units should prompt observation of patients' activity levels and engagement with people and available space to ensure optimal use of new environments.Promotion of communal spaces and activities away from the bedroom to encourage social engagement is recommended for patients recovering in rehabilitation facilities.Less time in contact with nursing staff in rehabilitation environments with predominantly single rooms suggests a review of clinical practice and patient safety is warranted.

New tuberculosis vaccines: advances in clinical development and modelling

Tuberculosis remains a major source of morbidity and mortality worldwide, with 10 million cases and 1.5 million deaths in 2018. Achieving 'End TB' prevention and care goals by 2035 will likely require a new tuberculosis vaccine. The tuberculosis vaccine development pipeline has seen encouraging progress; however, questions around their population impact and implementation remain. Mathematical modelling investigates these questions to inform vaccine development and deployment strategies. We provide an update on the current vaccine development pipeline, and a systematic literature review of mathematical modelling of the epidemiological impact of new tuberculosis vaccines. Fourteen prophylactic tuberculosis vaccine candidates are currently in clinical trials. Two candidates have shown promise in phase II proof-of-concept efficacy trials: M72/AS01_E demonstrated 49.7% (95% CI; 2.1, 74.2) protection against tuberculosis disease, and BCG revaccination demonstrated 45.4% (95% CI; 6.4, 68.1) protection against sustained Mycobacterium tuberculosis infection. Since the last modelling review, new studies have investigated the epidemiological impact of differential vaccine characteristics, age targeting and spatial/risk group targeting. Critical research priorities for M72/AS01_E include completing the currently in-design trial, powered to improve the precision of efficacy estimates, include uninfected populations and further assess safety and immunogenicity in HIV-infected people. For BCG revaccination, the priority is completing the ongoing confirmation of efficacy trial. Critical modelling gaps remain on the full value proposition of vaccines, comparisons with other interventions and more realistic implementation strategies. Using carefully designed trials and modelling, we must prepare for success, to ensure that new vaccines will be promptly received by those most in need.

Heart failure following cancer treatment: characteristics, survival and mortality of a linked health data analysis

BACKGROUND

Cardiotoxicity resulting in heart failure is a devastating complication of cancer therapy. A patient may survive cancer only to develop heart failure (HF), which has a higher mortality rate than some cancers.

AIM

This study aimed to describe the characteristics and outcomes of HF in patients with blood or breast cancer after chemotherapy treatment.

METHODS

Queensland Cancer Registry, Death Registry and Hospital Administration records were linked (1996-2009). Patients were categorised as those with an index HF admission (that occurred after cancer diagnosis) and those without an index HF admission (non-HF).

RESULTS

A total of 15 987 patients was included, and 1062 (6.6%) had an index HF admission. Median age of HF patients was 67 years (interquartile range 58-75) versus 54 years (interquartile range 44-64) for non-HF patients. More men than women developed HF (48.6% vs 29.5%), and a greater proportion in the HF group had haematological cancer (83.1%) compared with breast cancer (16.9%). After covariate adjustment, HF patients had increased mortality risk compared with non-HF patients (hazard ratios 1.67 (95% confidence interval, 1.54-1.81)), and 47% of the index HF admission occurred within 1 year from cancer diagnosis and 70% within 3 years.

CONCLUSION

Cancer treatment may place patients at a greater risk of developing HF. The onset of HF occurred soon after chemotherapy, and those who developed HF had a greater mortality risk.

INTU is essential for oncogenic Hh signaling through regulating primary cilia formation in basal cell carcinoma

Inturned (INTU), a cilia and planar polarity effector (CPLANE), performs prominent ciliogenic functions during morphogenesis, such as in the skin. INTU is expressed in adult tissues but its role in tissue maintenance is unknown. Here, we report that the expression of the INTU gene is aberrantly elevated in human basal cell carcinoma (BCC), coinciding with increased primary cilia formation and activated hedgehog (Hh) signaling. Disrupting Intu in an oncogenic mutant Smo (SmoM2)-driven BCC mouse model prevented the formation of BCC through suppressing primary cilia formation and Hh signaling, suggesting that Intu performs a permissive role during BCC formation. INTU is essential for IFT-A complex assembly during ciliogenesis. To further determine whether Intu is directly involved in the activation of Hh signaling downstream of ciliogenesis, we examined the Hh signaling pathway in mouse embryonic fibroblasts, which readily respond to Hh pathway activation. Depleting Intu blocked SAG-induced Hh pathway activation, whereas the expression of Gli2ΔN, a constitutively active Gli2, restored Hh pathway activation in Intu-deficient cells, suggesting that INTU functions upstream of Gli2 activation. In contrast, overexpressing Intu did not promote ciliogenesis or Hh signaling. Taken together, data obtained from this study suggest that INTU is indispensable during BCC tumorigenesis and that its aberrant upregulation is likely a prerequisite for primary cilia formation during Hh-dependent tumorigenesis.

Standing balance post total knee arthroplasty: sensitivity to change analysis from four to twelve weeks in 466 patients

OBJECTIVE

Little is known about how static standing balance changes post total knee arthroplasty (TKA). The primary aim of this study was to examine the sensitivity to change and redundancy of center of pressure (COP) variables post-TKA. The secondary aim was to compare the sensitivity of these measures to standard clinical assessments of one repetition maximum knee extension strength and fast pace gait speed.

DESIGN

466 participants performed instrumented double-limb standing balance tests with eyes open at 4 and 12 weeks post-TKA. Measures of COP standard deviation, amplitude, root mean square (RMS), path length, detrended fluctuation analysis (DFA) and signal frequency content for the medial-lateral (ML) and anterior-posterior (AP) axes were examined.

RESULTS

Significant decreases in total path length, ML variables related to sway velocity and AP signal complexity and frequency were observed. Inter-session Cohen's d effect size (ES) revealed the strongest effect was for high velocity ML path length, with a 12% decrease in this rapid sway. This variable, along with AP mean instantaneous frequency and AP DFA, were the only ones significantly different with effect sizes >0.20 and non-redundant (Spearman's rho <0.75). The ES of COP-derived variables (maximum = 0.45) were lower than gait speed (1.40) and knee extensor strength (1.54).

CONCLUSION

Increased high velocity ML sway is present at four compared to 12 weeks post-TKA. This augmented rapid sway may provide increased challenges to the postural control system at a time coinciding with reduced strength levels, which could have implications for physical function during activities of daily living.

Codominant Role of Interferon-γ- and Interleukin-17-Producing T Cells During Rejection in Full Facial Transplant Recipients

Facial transplantation is a life-changing procedure for patients with severe composite facial defects. However, skin is the most immunogenic of all transplants, and better understanding of the immunological processes after facial transplantation is of paramount importance. Here, we describe six patients who underwent full facial transplantation at our institution, with a mean follow-up of 2.7 years. Seum, peripheral blood mononuclear cells, and skin biopsy specimens were collected prospectively, and a detailed characterization of their immune response (51 time points) was performed, defining 47 immune cell subsets, 24 serum cytokines, anti-HLA antibodies, and donor alloreactivity on each sample, producing 4269 data points. In a nonrejecting state, patients had a predominant T helper 2 cell phenotype in the blood. All patients developed at least one episode of acute cellular rejection, which was characterized by increases in interferon-γ/interleukin-17-producing cells in peripheral blood and in the allograft's skin. Serum monocyte chemotactic protein-1 level was significantly increased during rejection compared with prerejection time points. None of the patients developed de novo donor-specific antibodies, despite a fourfold expansion in T follicular helper cells at 1 year posttransplantation. In sum, facial transplantation is frequently complicated by a codominant interferon-γ/interleukin-17-mediated acute cellular rejection process. Despite that, medium-term outcomes are promising with no evidence of de novo donor-specific antibody development.

Novel application of high-dose rate brachytherapy for severe, recalcitrant palmoplantar pustulosis

Palmoplantar pustulosis (PPP) is a chronic pustular dermatitis of the palms and soles, which is frequently associated with significant pruritus and pain, often limiting daily activities. We present the case of a 36-year-old man with severe PPP who had treatment failure with multiple medical therapies but showed marked improvement with high-dose rate brachytherapy. Brachytherapy has the advantage of providing a conformal dose distribution over complex curved surfaces, such as the foot and ankle. Our observations suggest that brachytherapy may be a well-tolerated treatment option for patients with severe, refractory PPP.

Early changes in Achilles tendon behaviour in vivo following downhill backwards walking

Downhill backwards walking causes repeated, cyclical loading of the muscle-tendon unit. The effect this type of repeated loading has on the mechanical behaviour of the Achilles tendon is presently unknown. This study aimed to investigate the biomechanical response of the Achilles tendon aponeurosis complex following a downhill backwards walking protocol. Twenty active males (age: 22.3 ± 3.0 years; mass: 74.7 ± 5.6 kg; height: 1.8 ± 0.7 m) performed 60 min of downhill (8.5°), backwards walking on a treadmill at -0.67 m · s(-1). Data were collected before, immediately post, and 24-, 48- and 168-h post-downhill backwards walking. Achilles tendon aponeurosis elongation, strain and stiffness were measured using ultrasonography. Muscle force decreased immediately post-downhill backward walking (P = 0.019). There were increases in Achilles tendon aponeurosis stiffness at 24-h post-downhill backward walking (307 ± 179.6 N · mm(-1), P = 0.004), and decreases in Achilles tendon aponeurosis strain during maximum voluntary contraction at 24 (3.8 ± 1.7%, P = 0.008) and 48 h (3.9 ± 1.8%, P = 0.002) post. Repeated cyclical loading of downhill backwards walking affects the behaviour of the muscle-tendon unit, most likely by altering muscle compliance, and these changes result in tendon stiffness increases.

Hematopoietic knockdown of PPARδ reduces atherosclerosis in LDLR-/- mice

PPARδ (peroxisome proliferator-activated receptor δ) mediates inflammation in response to lipid accumulation. Systemic administration of a PPARδ agonist can ameliorate atherosclerosis. Paradoxically, genetic deletion of PPARδ in hematopoietic cells led to a reduction of atherosclerosis in murine models, suggesting that downregulation of PPARδ expression in these cells may mitigate atherogenesis. To advance this finding forward to potential clinical translation through hematopoietic stem cell transplantation-based gene therapy, we employed a microRNA (miRNA) approach to knock down PPARδ expression in bone marrow cells followed by transplantation of the cells into LDLR-/- mice. We found that knockdown of PPARδ expression in the hematopoietic system caused a dramatic reduction in aortic atherosclerotic lesions. In macrophages, a key component in atherogenesis, knockdown of PPARδ led to decreased expression of multiple pro-inflammatory factors, including monocyte chemoattractant protein-1 (MCP-1), interleukin (IL)-1β and IL-6. Expression of CCR2, a receptor for MCP-1, was also decreased. The downregulation of pro-inflammatory factors is consistent with significant reduction of macrophage presence in the lesions, which may also be attributable to elevation of ABCA1 (ATP-binding cassette, subfamily A, member 1) and depression of adipocyte differentiate-related protein. Furthermore, the abundance of both MCP-1 and matrix metalloproteinase-9 proteins was reduced in plaque areas. Our results demonstrate that miRNA-mediated PPARδ knockdown in hematopoietic cells is able to ameliorate atherosclerosis.

Mycoplasma genitalium infection among HIV-positive women: prevalence, risk factors and association with vaginal shedding

This study examined the prevalence and factors associated with Mycoplasma genitalium (MG) infection among HIV-positive women and the association between MG and vaginal HIV-1 RNA shedding. HIV-positive women attending an outpatient clinic in New Orleans, Louisiana, USA, from 2002 to 2005 were examined for a battery of sexually transmitted infections (STIs) and underwent a behavioural survey. A selected subset had a measurement of vaginal shedding analysed. Of the 324 HIV-positive women, 32 (9.9%) were infected with MG. HIV-positive women with MG were more likely to be co-infected with Neisseria gonorrhoeae and Chlamydia trachomatis and to have had ≥1 male sexual partners in the last month. In the subset (n = 164), no differences were found in the presence of detectable vaginal HIV-1 RNA between women infected and not infected with MG (30.8% versus 34.8% shedding; P = 0.69). While MG was a common co-STI in this sample of HIV-positive women, it was not associated with vaginal HIV shedding.

Macrophage LXRα gene therapy ameliorates atherosclerosis as well as hypertriglyceridemia in LDLR(-/-) mice

Liver X receptors (LXRs) are implicated in the regulation of cholesterol homeostasis, inflammatory response and atherogenesis. Administration of LXR agonists inhibits the progress of atherosclerosis, and also increases plasma triglyceride levels, representing an obstacle to their use in treating this disease. The objective of this study was to develop an alternative approach that could overcome this obstacle. Eight-week-old low-density lipoprotein receptor-deficient (LDLR(-/-)) mice were transplanted with hematopoietic stem cell (HSC)-enriched bone marrow cells transduced with lentivectors expressing either green fluorescent protein (GFP) (Lenti-SP-GFP, control) or LXRα (Lenti-SP-LXRα) driven by a synthetic macrophage promoter. At 4 weeks post-transplant, the mice were fed with a Western diet for 8 weeks and then killed. Compared with Lenti-SP-GFP mice, the Lenti-SP-LXRα mice had a 30% reduction in atherosclerotic lesions, which was accompanied by increases in levels of macrophage expression of cholesterol efflux genes apolipoprotein E and ATP-binding cassette A1, as well as decreases in plasma inflammatory cytokines interleukin-6 and tumor necrosis factor-α. Intriguingly, a 50% reduction of plasma triglyceride level was also observed. We conclude that HSC-based macrophage LXRα gene therapy ameliorates the development of atherosclerosis along with an unexpected concomitant reduction of plasma triglyceride levels in LDLR(-/-) mice. These findings highlight the potential value of macrophage LXR expression as an avenue for therapeutic intervention against atherosclerosis.

Iliotibial band syndrome: an examination of the evidence behind a number of treatment options

Iliotibial band (ITB) syndrome (ITBS) is a common cause of distal lateral thigh pain in athletes. Treatment often focuses on stretching the ITB and treating local inflammation at the lateral femoral condyle (LFC). We examine the area's anatomical and biomechanical properties. Anatomical studies of the ITB of 20 embalmed cadavers. The strain generated in the ITB by three typical stretching maneuvers (Ober test; Hip flexion, adduction and external rotation, with added knee flexion and straight leg raise to 30 degrees ) was measured in five unembalmed cadavers using strain gauges. Displacement of the Tensae Fasciae Latae (TFL)/ITB junction was measured on 20 subjects during isometric hip abduction. The ITB was uniformly a lateral thickening of the circumferential fascia lata, firmly attached along the linea aspera (femur) from greater trochanter up to and including the LFC. The microstrain values [median (IQR)] for the OBER [15.4(5.1-23.3)me], HIP [21.1(15.6-44.6)me] and SLR [9.4(5.1-10.7)me] showed marked disparity in the optimal inter-limb stretching protocol. HIP stretch invoked significantly (Z=2.10, P=0.036) greater strain than the SLR. TFL/ITB junction displacement was 2.0+/-1.6 mm and mean ITB lengthening was <0.5% (effect size=0.04). Our results challenge the reasoning behind a number of accepted means of treating ITBS. Future research must focus on stretching and lengthening the muscular component of the ITB/TFL complex.

Isolation and functional analysis of neutrophils

This unit describes the isolation of high-purity neutrophils (or polymorphonuclear leukocytes; PMN) and the assays that can be performed to assess their function. An assay for the in vitro study of phagocytic capacity is presented, and microbicidal assays using lysostaphin and differential centrifugation are also described. During phagocytosis or on exposure to soluble agonists, neutrophils exhibit a marked increase in oxidative metabolism which is mediated by activation of NADPH oxidase and results in the formation of superoxide anion as well as hydrogen peroxide and other reactive species. The nitroblue tetrazolium reduction slide test is presented, and is a nonquantitative screening test for the presence of reactive oxygen products. The quantitation of superoxide by the kinetic and static assays are detailed, and a "broken cell" assay is also outlined.Finally, measurement of hydrogen peroxide formation is described.

Alcohol consumption, ART usage and high-risk sex among women infected with HIV

We examine the role of alcohol consumption on sexual risk behavior among a cohort of 187 sexually active HIV-infected women (aged 18-61) in care at an urban ambulatory clinic in New Orleans, Louisiana, U.S. Sexual risk behavior among women on and off antiretroviral therapy (ART) and the relationship between alcohol use, ART, and behavior was also explored. One-fourth of respondents were classified as binge drinkers and the average number of drinking occasions per week ranged from none to 10-12. Approximately 60% were prescribed ART and self-reported adherence was 90%. One-third of the women reported no condom use at last vaginal sex, 62% reported inconsistent condom use for vaginal sex, and 7% had multiple male sex partners in the last month. Binge alcohol users and women on ART were significantly more likely to participate in each sexual risk outcome examined. Partner refusal of condom use was also significantly associated with binge drinking patterns. Results lend strength to the equivocal literature on the relationship between both alcohol and prescription of ART and sexual behavior. Enhanced detection of alcohol abuse, coupled with risk reduction counseling especially among women prescribed ART are important clinical practices in treating women with HIV.

An Investigation into the Dynamic Effects on the Track of Wheelflats on Railway Vehicles

Wheelflats on railway vehicles are created by wheelslide in braking: the resulting imperfection in the running line generates dynamic forces and stresses at each subsequent revolution. The authors describe this problem and refer to earlier work on this topic. A field experiment is described, in which an irregularity in the railhead was used to simulate a wheelflat for a range of vehicles, and loads and rail stresses were monitored. The structure and solution procedures of three theoretical models of the vehicle/track system are outlined and typical results are compared with the experimental data to establish the adequacy and limitations of each of the models.

Although this paper is primarily concerned with railway track dynamics, the mathematical techniques described could be applied to any problem involving the impact loading of beams.

Reliability and validity of the SF-36 in HIV-infected homeless and marginally housed individuals

OBJECTIVE

To assess the reliability and validity of the Short-Form 36 (SF-36) health survey as a health status indicator among HIV-infected homeless and marginally housed (HMH) individuals.

METHODS

Between July 1996 and May 2000, a sample of HMH individuals completed interviews that included the SF-36. Responses to the SF-36 were analyzed for missing data, range, internal consistency, and construct validity.

RESULTS

Among 330 individuals interviewed, 83% were male, 43% were African-American, and the median age was 39 years. All internal consistency reliability coefficients exceeded 0.70, all item-scale correlations exceeded 0.40, all items were more strongly correlated with their hypothesized scale than any other scale, and all reliability coefficients exceeded inter-scale correlations for the same scale. Three of four physical health scales were significantly associated with CD4 cell count and HIV viral load. All scales were significantly associated with depression.

DISCUSSION

We found that scales were internally consistent, items correlated to an acceptable degree with their hypothesized scales, items were distinct from other scales, physical scales were associated with CD4 cell count and viral load, and all scales were associated with depression. These analyses provide evidence for the reliability and validity of the SF-36 as a measure of health status in HIV-positive HMH individuals.

What predicts poor collection of medication among children with asthma? A case-control study

Compliance with asthma medication is recognised to be a problem. Acquisition of medication is the first step towards compliance. Factors predicting poor collection of prophylactic medication were investigated. A case/control study was conducted. Cases were children who had had at least two consultations for poorly controlled asthma in 1 yr and collected prescriptions of prophylactic medication irregularly. Controls were children whose prescriptions were collected as instructed. Levels of knowledge about asthma and asthma medication were high in both groups. Parents of cases were more likely to perceive their child's asthma to be moderate or severe and more likely to report that their child's asthma was not well controlled. They reported more night-time symptoms, exercise symptoms and school absence. Parents of cases were less likely to report that administering inhalers was part of the evening routine. They were less likely to perceive their child's prophylactic medication to be very effective and more reluctant to administer prophylactic medication. Some parents may decide to undertreat their children, although lack of organised routine may contribute to poor compliance. Parents need guidance on interpreting symptoms and support in establishing routines for the administration of medication.

Cost consequences of sentinel lymph node biopsy in the treatment of breast cancer. A preliminary analysis

OBJECTIVES

To assess whether sentinel lymph node biopsy (SLNB), an alternative to axillary lymph node dissection in treating female breast cancer, affords any cost savings.

METHODS

We profile cumulative treatment costs of 811 breast cancer patients, 555 of whom received SLNB. Univariate and multivariate statistical tests are used to appraise whether these cost profiles differ between SLNB and other patients.

RESULTS

The statistical results are mixed. However, none supports the conjecture that SLNB necessarily lowers the cost of treating the average breast patient.

CONCLUSIONS

SLNB may be cost-effective, but longer term costs and outcomes must be estimated before firm conclusions can be reached.

Fibrinogen and fibrin are anti-adhesive for keratinocytes: a mechanism for fibrin eschar slough during wound repair

During cutaneous wound repair the epidermis avoids the fibrin-rich clot; rather it migrates down the collagen-rich dermal wound margin and over fibronectin-rich granulation tissue. The mechanism(s) underlying keratinocyte movement in this precise pathway has not been previously addressed. Here we demonstrate that cultured human keratinocytes do not express functional fibrinogen/fibrin receptors, specifically alpha v beta 3. Biologic modifiers known to induce integrin expression or activation did not induce adhesion to fibrin, fibrinogen, or its fragments. Epidermal explant outgrowth and single epidermal cell migration failed to occur on either fibrin or fibrinogen. Surprisingly, fibrin and fibrinogen mixed at physiologic molar ratios with fibronectin abrogated keratinocyte attachment to fibronectin. Keratinocytes transduced with the beta 3 integrin subunit cDNA, expressed alpha v beta 3 on their surface and attached to and spread on fibrinogen and fibrin. beta-gal cDNA-transduced keratinocytes did not demonstrate this activity. Furthermore, beta 3 cDNA-transduced keratinocyte adhesion to fibrin was inhibited by LM609 monoclonal antibody to alpha v beta 3 in a concentration-dependent fashion. From these data, we conclude that normal human keratinocytes cannot interact with fibrinogen and its derivatives due to the lack of alpha v beta 3. Thus, fibrinogen and fibrin are authentic anti-adhesive for keratinocytes. This may be a fundamental reason why the migrating epidermis dissects the fibrin eschar from wounds.

Transient eruptive seborrheic keratoses associated with erythrodermic psoriasis and erythrodermic drug eruption: report of two cases

The appearance of multiple seborrheic keratoses in association with underlying internal malignancy (known as the sign of Leser-Trelat) has generated much discussion and debate in the literature. However, comparatively few case reports exist that examine the appearance of multiple seborrheic keratoses associated with exfoliative erythroderma without underlying malignancy. We report 2 cases in which multiple, biopsy-proven seborrheic keratoses appeared in conjunction with erythrodermic skin eruptions. The underlying diseases in these 2 patients included psoriasis and an eczematous drug eruption; in both cases the erythroderma resolved with appropriate treatment. After resolution of the erythroderma, the newly developed seborrheic keratoses proceeded to involute and gradually fall off. Neither of the patients exhibited any evidence of internal malignancy. These cases represent the first reports of psoriasis and drug eruption as causes of erythroderma-induced transient eruptive seborrheic keratoses. Clinical and pathologic findings are consistent with previous descriptions of this entity.

Frequency of anovulation and early menopause among women enrolled in selected adult AIDS clinical trials group studies

To obtain information on the prevalence of anovulation and early menopause and on pituitary-gonadal function among human immunodeficiency virus type 1-infected women, a study was undertaken that used stored serum samples from women aged 20-42 years who participated in selected Adult AIDS Clinical Trials Group protocols. Defined progesterone and follicle-stimulating hormone (FSH) levels were considered presumptive evidence of ovulation and of menopause, respectively. Anovulation occurred in 16 (48%) of 33 women for whom progesterone levels were tested; early menopause occurred in 2 (8%) of 24 women for whom FSH levels were tested. No statistically significant differences were seen in the demographic and clinical characteristics of anovulatory and ovulatory women, although women who ovulated had higher CD4 T cell counts and were less likely to have reported a recent change in menstrual periods. These data support the findings of prior studies of increased frequency of amenorrhea and/or irregular menstrual cycles, particularly among women with lower CD4 T cell counts.

Digital mammography: wavelet transform and Kalman-filtering neural network in mass segmentation and detection

RATIONALE AND OBJECTIVES

The authors developed a new adaptive module to improve their computer-assisted diagnostic (CAD) method for mass segmentation and classification. The goal was an adaptive module that used a novel four-channel wavelet transform with neural network rather than a two-channel wavelet transform with manual subimage selection. The four-channel wavelet transform is used for image decomposition and reconstruction, and a novel Kalman-filtering neural network is used for adaptive subimage selection.

MATERIALS AND METHODS

The adaptive CAD module was compared with the nonadaptive module by comparing receiver operating characteristic curves for the whole CAD system. An image database containing 800 regions of interest enclosing all mass types and normal tissues was used for the relative comparison of system performance, with electronic ground truth established in advance.

RESULTS

The receiver operating characteristic curves yield Az values of 0.93 and 0.86 with and without the adaptive module respectively, suggesting that overall CAD performance is improved with the adaptive module.

CONCLUSION

The results of this study confirm the importance of using a new class of adaptive CAD methods that allow a more generalized application for larger image databases or images generated from different sensors or by means of direct x-ray detection, as required for clinical trials.

Transcriptional regulation of the p67phox gene: role of AP-1 in concert with myeloid-specific transcription factors

We have investigated the myeloid-specific transcriptional regulation of p67(phox), an essential component of phagocyte respiratory burst NADPH oxidase. Analysis was carried out on the p67(phox) 5'-flanking region from -3669 to -4 (relative to ATG), including the first exon and intron and part of the second exon. The construct extending from -985 to -4 produced the highest luciferase activity in myeloid HL-60 cells but was not active in HeLa or Jurkat cells, indicating myeloid-specific expression. Four active elements were identified: Sp1/Sp3 at -694, PU.1 at -289, AP-1 at -210, and PU.1/HAF1 at -182, the latter three being in the first intron. These cis elements bound their cognate transacting factors both in vitro and in vivo. Mutation of the Sp1, PU.1, or PU.1/HAF1 site each decreased promoter activity by 35-50%. Mutations in all three sites reduced promoter activity by 90%. However, mutation of the AP-1 site alone nearly abolished promoter activity. The AP-1 site bound Jun and Fos proteins from HL-60 cell nuclear extract. Co-expression with Jun B in AP-1-deficient cells increased promoter activity by 3-fold. These data show that full p67(phox) promoter activity requires cooperation between myeloid-specific and nonmyeloid transcription factors, with AP-1 being the most critical for function.

Magnetic resonance imaging of the breast

BACKGROUND

Magnetic resonance imaging (MRI) has the potential to become a useful adjunct in breast imaging. Contrast-enhanced breast MRI has demonstrated a high sensitivity in the detection of invasive breast cancer. In clinical studies, breast MRI has often altered the course of patient care. Although promising results have been generated, MRI of the breast is currently in a development stage.

METHODS

The authors reviewed the literature on the potential indications, sensitivity, specificity, and limitations of MRI of the breast.

RESULTS

Reported advantages of MRI of the breast over conventional imaging techniques include improved staging and treatment planning, enhanced evaluation of the augmented breast, better detection of recurrence, and improved screening of high-risk women. Contrast-enhanced breast MRI is a sensitive modality for detecting breast cancer, but its variable specificity is a major limitation.

CONCLUSIONS

MRI of the breast is emerging as a valuable adjunct to mammography and sonography for specific clinical indications. Additional clinical studies that define indications, interpretation criteria, imaging parameters, and cost effectiveness are needed. A multi-institutional study designed to address these issues is in progress.

Fibrin and wound healing

Although hemostasis is the major role of fibrin in wound repair, once the clot is present the wound cells must deal with it. The invasion and clearing of fibrin by these cells involves multiple complex processes that may go array XXX and delay wound repair. A good example, of the latter is leg ulcers. These chronic wounds contain a plethora of proteases that digest fibronectin and growth factors in the fibrin clot resulting in a corrupt provisional matrix that no longer supports reepithelialization or granulation tissue formation. Every good wound care provider knows that these wounds will not heal unless the corrupt matrix is removed by vigorous debridement that stimulates the accumulation of a competent provisional matrix.

Improved method for automatic identification of lung regions on chest radiographs

RATIONALE AND OBJECTIVES

The authors performed this study to evaluate an algorithm developed to help identify lungs on chest radiographs.

MATERIALS AND METHODS

Forty clinical posteroanterior chest radiographs obtained in adult patients were digitized to 12-bit gray-scale resolution. In the proposed algorithm, the authors simplified the current approach of edge detection with derivatives by using only the first derivative of the horizontal and/or vertical image profiles. In addition to the derivative method, pattern classification and image feature analysis were used to determine the region of interest and lung boundaries. Instead of using the traditional curve-fitting method to delineate the lung, the authors applied an iterative contour-smoothing algorithm to each of the four detected boundary segments (costal, mediastinal, lung apex, and hemidiaphragm edges) to form a smooth lung boundary.

RESULTS

The algorithm had an average accuracy of 96.0% for the right lung and 95.2% for the left lung and was especially useful in the delineation of hemidiaphragm edges. In addition, it took about 0.775 second per image to identify the lung boundaries, which is much faster than that of other algorithms noted in the literature.

CONCLUSION

The computer-generated segmentation results can be used directly in the detection and compensation of rib structures and in lung nodule detection.

Timing of postoperative adjustment in adjustable suture strabismus surgery

PURPOSE

The use of adjustable sutures in strabismus surgery has increased the rate of surgical success. Little data are available on the optimum timing for postoperative adjustment after strabismus surgery. We wanted to compare 2 common practices of adjustable suture technique after strabismus surgery.

METHODS

Two comparable groups of 40 patients each, who had strabismus surgery with adjustable suture technique, were prospectively studied. Group A had early adjustment the same day of the surgery about 6 hours after the operation, and group B had late adjustment the next day about 24 hours after the operation. Subjective scoring tables were used to evaluate the pain felt by the patient before, during, and after the adjustment and any difficulties of the adjustment process. Requirements of postoperative pain medications and final alignment 6 weeks after surgery were also compared.

RESULTS

Despite adequate statistical power, no significant differences were found between the groups regarding pain before, during, and after adjustment, difficulties performing the adjustment, and final alignment after 6 weeks (P > .05). Both adjustment schedules were equally associated with mild to moderate pain before, during, and after the adjustment. In the first 24 hours after surgery, no overall difference in the use of pain medications was found. Nausea and vomiting in the first 24 postoperative hours were more common in the early adjustment group (P = .02).

CONCLUSION

The surgeon can feel free to choose the timing for postoperative adjustment. However, when performing an early adjustment, the surgeon should be especially prepared to control nausea and vomiting.

Concordance between the CC chemokine receptor 5 genetic determinants that alter risks of transmission and disease progression in children exposed perinatally to human immunodeficiency virus

If CC chemokine receptor 5 (CCR5)-dependent mechanisms at the time of initial virus exposure are important determinants of virus entry and disease outcome, then the polymorphisms in CCR5 that influence risk of transmission and disease progression should be similar; this hypothesis was tested in a cohort of 649 Argentinean children exposed perinatally to human immunodeficiency virus type 1 (HIV-1). Two lines of evidence support this hypothesis. First, CCR5 haplotype pairs associated with enhanced risk of transmission were the chief predictors of a faster disease course. Second, some of the haplotype pairs associated with altered rates of transmission and disease progression in children were similar to those that we previously found influenced outcome in European American adults. This concordance suggests that CCR5 haplotypes may serve as genetic rheostats that influence events occurring shortly after initial virus exposure, dictating not only virus entry but, by extension, also the extent of early viral replication.

Cases from the Aerospace Medicine Residents' Teaching File: acute onset of dizziness in a USAF aviator

An Air Force F-15 pilot develops the sudden onset of incapacitating dizziness with nausea and vomiting not associated with flight. Presentation, diagnosis, treatment, and aeromedical issues surrounding the symptom complex of acute onset vertigo is discussed.

Global survey of genetic variation in CCR5, RANTES, and MIP-1alpha: impact on the epidemiology of the HIV-1 pandemic

Expression of CC chemokine receptor 5 (CCR5), the major coreceptor for HIV-1 cell entry, and its ligands (e.g., RANTES and MIP-1alpha) is widely regarded as central to the pathogenesis of HIV-1 infection. By surveying nearly 3,000 HIV+ and HIV- individuals from worldwide populations for polymorphisms in the genes encoding RANTES, MIP-1alpha, and CCR5, we show that the evolutionary histories of human populations have had a significant impact on the distribution of variation in these genes, and that this may be responsible, in part, for the heterogeneous nature of the epidemiology of the HIV-1 pandemic. The varied distribution of RANTES haplotypes (AC, GC, and AG) associated with population-specific HIV-1 transmission- and disease-modifying effects is a striking example. Homozygosity for the AC haplotype was associated with an increased risk of acquiring HIV-1 as well as accelerated disease progression in European Americans, but not in African Americans. Yet, the prevalence of the ancestral AC haplotype is high in individuals of African origin, but substantially lower in non-Africans. In a Japanese cohort, AG-containing RANTES haplotype pairs were associated with a delay in disease progression; however, we now show that their contribution to HIV-1 pathogenesis and epidemiology in other parts of the world is negligible because the AG haplotype is infrequent in non-Far East Asians. Thus, the varied distribution of RANTES, MIP-1alpha, and CCR5 haplotype pairs and their population-specific phenotypic effects on HIV-1 susceptibility and disease progression results in a complex pattern of biological determinants of HIV-1 epidemiology. These findings have important implications for the design, assessment, and implementation of effective HIV-1 intervention and prevention strategies.