Risk of Radiation-Associated Secondary Malignancies among Patients with Breast Cancer Harboring TP53 Germline Variants

PURPOSE/OBJECTIVE(S)

Radiation-associated malignancies are rare and poorly understood. TP53 encodes a multifunctional protein that maintains genome integrity and is the most common somatically mutated gene in cancer. Germline pathogenic variants of TP53 predispose carriers to several cancers comprising the Li-Fraumeni syndrome. It is hypothesized that carriers are also at increased risk of radiotherapy (RT)-associated secondary malignancies; however, reports are mixed. We evaluated the risk of secondary malignancies after breast RT among patients with Li-Fraumeni syndrome.

MATERIALS/METHODS

This multi-institutional cohort study included carriers of TP53 germline variants who underwent surgical treatment for breast cancer between 1980 and 2020. Patients were stratified based on germline TP53 classification (pathogenic variants [PV] vs variants of uncertain significance [VUS]). The primary outcome of interest was the cumulative incidence risk of developing an in-field secondary cancer after radiotherapy for primary breast carcinoma.

RESULTS

Ninety-one patients (57 PV and 34 VUS) were evaluated with a median age of 36 years (interquartile range [IQR] 31, 42) and a median follow up of 7.9 years (IQR 4.7, 14.4). Among those with PV who received RT (n = 22), 4 secondary non-breast cancers developed in the radiation field (15-year cumulative incidence 19% [95% CI: 4-43%]), whereas, among those with PV who did not receive RT (n = 35), 0 secondary non-breast cancers were observed in the treated breast (15-year cumulative incidence 0%; p = 0.043). We observed 3 radiation-associated sarcomas among patients with PV who received RT (15-year risk 12% [95% CI 2-33%]) compared with 0 among those who did not receive RT (p = 0.08). No RT-associated sarcomas were observed among 18 patients with TP53 VUS who received RT. RT was not associated with overall survival, despite higher T and N breast cancer stage among those receiving RT (p = 0.33). As expected, patients with PV were more likely than those with VUS to develop any secondary cancer following breast cancer treatment (15-year risk: 54% [95% CI: 33-72%] vs. 14% [95% CI: 3-36%]).

CONCLUSION

Carriers of pathogenic variants of TP53 are at elevated risk of developing secondary malignancies after breast cancer treatment. This population is at particular risk of developing in-field secondary cancers following RT. This iatrogenic risk must be weighed against the anticipated therapeutic benefit of tumor control. Shared decision making is crucial in the radiotherapeutic management of breast cancer patients harboring the Li-Fraumeni syndrome.

Success of Liquid Tumor Biopsy in Men with Metastatic Prostate Cancer According to Self-Identified Race

PURPOSE/OBJECTIVE(S)

Liquid biopsy using cell-free DNA (cfDNA) is increasingly used to identify somatic prostate cancer (PrCa) alterations when tissue biopsy of a metastatic lesion is infeasible or impractical. High-risk somatic alterations identified by cfDNA have been recently shown to predict the benefit of metastasis-directed therapy with stereotactic body radiation therapy in PrCa. However, given the older age of PrCa patients, liquid biopsy is often contaminated with alterations related to clonal hematopoiesis of indeterminate potential (CHIP), generating uncertainty in the clinical utility of the results. Given the higher incidence and aggressiveness of metastatic PrCa in Black men, we sought to determine if the success of cfDNA testing varied by race in a large and diverse cohort of United States Veterans with metastatic PrCa, hypothesizing that race would not influence the success of cfDNA testing.

MATERIALS/METHODS

Veterans with metastatic PrCa underwent next-generation sequencing of cfDNA biopsy specimens through the VA National Precision Oncology Program from February 2019 to November 2022. Successful identification of PrCa with cfDNA testing was defined as the identification of an alteration in one or more PrCa-related related genes in the gene panel tested (AR, CDK12, SPOP, MED12, CCND1, BRAF, AKT1, TMPRSS2, ERG, ETV1, and ETV4). Univariate logistic regression was employed to explore the association between patient self-identified race, as well as other patient and disease-specific factors at the time of cfDNA biopsy, with the likelihood of yielding a successful cfDNA biopsy result.

RESULTS

A total of 2066 cfDNA tests from 1985 Veterans were related to a diagnosis of PrCa, passed quality control measures, and were linkable to patient-level demographics. Median age at testing was 74, median PSA at testing was 22.7, median PSA doubling time (PSADT) was 3.6 months, and median Gleason score was 8. 57% of Veterans self-identified as White, 33% as Black, and 10% as Other. Eight hundred fourteen (39%) tests were deemed successful by finding a PrCa related gene alteration. Among successful tests, the most frequently encountered alterations were AR alterations in 60.4% White men and 33.9% Black men (p = 0.72), followed by TMPRSS2 alterations in 70.3% White men and 22.0% Black men (p<0.001). Despite a lower rate of PrCa-specific alterations in Black men, on univariate analysis, Veteran self-identified race was not associated with successful cfDNA testing (OR 0.95, 95% CI 0.78-1.14, p = 0.6), whereas PSA in quintiles 2-4, PSADT <12 months, and unit increase in Gleason score were associated with successful cfDNA testing (p<0.01 for all).

CONCLUSION

Successful cfDNA biopsy in metastatic PrCa is associated with PSA and PSADT, but not related to patient self-identified race. In appropriate clinical scenarios, patients who self-identify as Black or White are equally likely to have PrCa-specific alterations detected on cfDNA testing when evaluating metastatic PrCa patients for local and systemic therapies.

Baseline prevalence of molecular marker of sulfadoxine/pyrimethamine resistance in Ebonyi and Osun states, Nigeria: amplicon deep sequencing of dhps-540

BACKGROUND

Chemoprevention plays an important role in malaria control strategy. Perennial malaria chemoprevention (PMC) using sulfadoxine/pyrimethamine (SP) is a WHO-approved strategy to combat malaria in young children and may lead to drug pressure. Introducing SP-PMC may therefore be compromised due to the emergence of Plasmodium falciparum resistant to SP, particularly mutation at K540E of the dihydropteroate synthase (dhps) gene. Molecular surveillance of resistance markers can support assessment of antimalarial efficacy and effectiveness. High prevalence of 540E is associated with reduced effectiveness of SP, and areas with more than 50% prevalence are considered unsuitable for intermittent preventative treatment in pregnancy (IPTp) implementation. Assessing 540E prevalence is an important undertaking before implementation of SP-PMC.

METHODS

We conducted a rapid surveillance of dhps-540E to assess the suitability of SP as PMC in field studies from Ebonyi and Osun states in Nigeria. We used an in-house developed amplicon deep-sequencing method targeting part of the dhps gene.

RESULTS

Our data reveal that 18.56% of individuals evaluated carried the 540E mutation mixed with the WT K540. Mutant variant 540E alone was not found, and 80% of isolates harboured only WT (K540). Clonal analysis of the sequencing data shows a very low proportion of 540E circulating in both states.

CONCLUSIONS

Our data show that both states are suitable for SP-PMC implementation and, based on this finding, SP-PMC was implemented in Osun in 2022. Continuous monitoring of 540E will be required to ensure the chemoprevention effectiveness of SP in Nigeria.

Optimizing the role of 'lead mothers' in seasonal malaria chemoprevention (SMC) campaigns: formative research in Kano State, northern Nigeria

BACKGROUND

Seasonal malaria chemoprevention (SMC) is a safe and effective intervention for preventing malaria in children under 5 years of age. Lead mothers are community health volunteers that help caregivers comply with monthly administration of anti-malarial drugs during SMC campaigns. The lead mother approach is used in several SMC implementing states across Nigeria, but there is lack of evidence about their roles and how effective they are. This study sought to better understand the current role of lead mothers, identify areas for improvement and ways to optimize the role of lead mothers during SMC campaigns.

METHODS

This paper reports the formative phase of a three-phased intervention development study. The formative phase involved semi-structured interviews with stakeholders from national, state, local government and community levels (n = 20). Thematic analysis was used to identify key themes, forming the basis of a subsequent co-design workshop with stakeholders routinely involved in SMC campaigns.

RESULTS

The findings of the formative phase converged around four overarching themes: skills and attributes required of lead mothers; factors that affect lead mother's roles; how lead mothers interact with Community Health Influencers Promoters Services (CHIPS) agents and re-imagining the role of lead mothers during SMC campaigns.

CONCLUSION

This formative work in Kano state indicates that through their strong connection to communities and unique relationship with caregivers, lead mothers can and do influence caregivers to adopt healthy behaviours during SMC campaigns. However, there is room for improvement in how they are recruited, trained and supervised. There is need to improve lead mothers' knowledge and skills through adequate training and supporting materials, so they can deliver targeted health messages to caregivers. Sustainability of the lead mother approach is at risk if policymakers do not find a way of transitioning their role into the existing community health worker infrastructure, for example by using CHIPs agents, and ensuring less reliance on external donor support.

197 IMPROVING THE ASSESSMENT OF VISION IN OLDER ADULTS AT RISKS OF FALLS AT A DAY REHABILITATION CLINIC

Background

Assessment of vision is a key component of multifactorial falls prevention programmes. However, the National Audit of Inpatient Falls (2015) found less than half of older adults had a vision assessment when admitted to hospital. We suspected vision assessment could also be improved for patients attending our outpatient Day Rehabilitation Unit who were falling or at risk of falls.

Methods

21 outpatients were audited initially, with determination of baseline characteristics including age and Rockwood frailty score. We assessed whether past ophthalmological history was documented, whether the patient wore glasses and whether they had had a recent eye test in the community. Finally, documentation regarding visual examination was audited; this comprised range of eye movement, visual fields and visual acuity assessments. We adapted the clinic proforma to include a specific section on ophthalmology history and visual assessment; 14 patients were re-audited following intervention.

Results

Our two groups were relatively similar: mean age of 80 in the initial audit and 78 in the subsequent audit. Both groups had an average Rockwood score of 5. Improvements were noted in documentation regarding previous eye testing (33.3% - 86%), testing of eye movements (71.4% - 100%, and testing of visual fields (66.7% - 93%). There remained no testing of visual acuity following intervention.

Conclusion

A dedicated falls proforma targeting specific risk factors for falls improves identification and assessment of those risks. This enables targeted intervention and referral to be made to improve patient outcomes. For further improvement we would recommend educating the multidisciplinary team on how to test for visual acuity in the outpatient setting.

Co-implementing vitamin A supplementation with seasonal malaria chemoprevention in Sokoto State, Nigeria: a feasibility and acceptability study

Background

Bi-annual high dose vitamin A supplements administered to children aged 6–59 months can significantly reduce child mortality, but vitamin A supplementation (VAS) coverage is low in Nigeria. The World Health Organization recommends that VAS be integrated into other public health programmes which are aimed at improving child survival. Seasonal malaria chemoprevention (SMC) provides a ready platform for VAS integration to improve health outcomes. This study explored the feasibility and acceptability of integrating VAS with SMC in one local government area in Sokoto State.

Methods

A concurrent QUAN-QUAL mixed methods study was used to assess the feasibility and acceptability of co-implementing VAS with SMC in one LGA of Sokoto state. Existing SMC implementation tools and job aids were revised and SMC and VAS were delivered using a door-to-door approach. VAS and SMC coverage were subsequently assessed using questionnaires administered to 188 and 197 households at baseline and endline respectively. The qualitative component involved key informant interviews and focus group discussions with policymakers, programme officials and technical partners to explore feasibility and acceptability. Thematic analysis was carried out on the qualitative data.

Results

At endline, the proportion of children who received at least one dose of VAS in the last six months increased significantly from 2 to 59% (p < 0.001). There were no adverse effects on the coverage of SMC delivery with 70% eligible children reached at baseline, increasing to 76% (p = 0.412) at endline. There was no significant change (p = 0.264) in the quality of SMC, measured by proportion of children receiving their first dose as directly observed treatment (DOT), at baseline (54%) compared to endline (68%). The qualitative findings are presented as two overarching themes relating to feasibility and acceptability of the integrated VAS-SMC strategy, and within each, a series of sub-themes describe study participants’ views of important considerations in implementing the strategy.

Conclusion

This study showed that it is feasible and acceptable to integrate VAS with SMC delivery in areas of high seasonal malaria transmission such as northern Nigeria, where SMC campaigns are implemented. SMC-VAS integrated campaigns can significantly increase vitamin A coverage but more research is required to demonstrate the feasibility of this integration in different settings and on a larger scale.

POS0579 ABSENCE OF ASSOCIATION BETWEEN ABATACEPT EXPOSURE LEVELS AND INITIAL INFECTION IN PATIENTS WITH RA: A POST HOC ANALYSIS OF THE RANDOMIZED, PLACEBO-CONTROLLED AVERT-2 STUDY

Background

Infections are the most commonly reported AE observed in patients with RA treated with immunosuppressive therapies and can be clinically significant. A recent review reported differences in the risk of infection for some biologics such as tocilizumab and TNF inhibitors.1 Abatacept selectively modulates T-cell co-stimulation and is approved for the treatment of RA. In patients with polyarticular-course juvenile idiopathic arthritis, no association was found between higher serum abatacept exposure and the incidence of infection.2 This has not been evaluated for adult patients with RA.

Objectives

To determine if higher serum abatacept exposure during treatment with SC abatacept was associated with increased risk of infection in adult patients with RA.

Methods

AVERT-2 (Assessing Very Early Rheumatoid arthritis Treatment-2) was a randomized, placebo-controlled study of SC abatacept + MTX vs abatacept placebo + MTX in MTX-naive, anti-citrullinated protein antibody–positive patients with early, active RA.3 A post hoc population pharmacokinetic (PK) analysis was performed using PK-evaluable patient data from the induction period (year 1) of AVERT-2. Association between steady-state abatacept exposure (min plasma concentration [Cmin], max plasma concentration [Cmax], and average plasma concentration [Cavg]) and first infection was evaluated using Kaplan–Meier plots of probability vs time on treatment by abatacept exposure quartiles and Cox proportional-hazards models.

Results

PK of SC abatacept was defined as a linear 2-compartment model with first-order absorption and first-order elimination. The findings of the updated PK analysis were consistent with those reported in prior population analyses of abatacept PK in adults with RA. The final model included effects of baseline body weight, estimated glomerular filtration rate, sex, age, albumin, MTX use, NSAID use, SJC, and race on abatacept clearance. The only covariate with a clinically relevant effect was higher body weight, which caused an increase in clearance and volume. Infections occurred in a total of 330/693 (47.6%; serious, 1.6%) patients treated with abatacept, and 134/301 (44.5%; serious, 1.3%) with placebo during the first year of AVERT-2. In patients taking abatacept, the mean (SD) study exposure to abatacept was 376 (60) days, while mean (SD) prednisone equivalent dose was 6.7 (3.8) mg/day and mean (SD) MTX dose was 9.6 (3.0) mg/week. No exposure–response relationship was observed between the probability of first infection and steady-state abatacept exposure quartiles (Cavg, Cmin, and Cmax), or compared with placebo (Figure 1A–C). Kaplan–Meier assessment also showed no increase in risk of infection with concomitant use of MTX and glucocorticoids.

Conclusion

No association was found between initial infection and steady-state abatacept exposure (Cavg, Cmin, Cmax) or MTX and glucocorticoid use in patients with RA treated with SC abatacept.

References

[1]Jani M, et al. Curr Opin Rheumatol 2019;31:285–92.

[2]Ruperto N, et al. J Rheumatol 2021;48:1073–81.

[3]Emery P, et al. Arthritis Rheumatol 2019;71(suppl 10):L11.

Acknowledgements

This study was sponsored by Bristol Myers Squibb. Writing and editorial assistance were provided by Fiona Boswell, PhD, of Caudex, and was funded by Bristol Myers Squibb. Support was provided by Sandra Overfield as Protocol Manager, and Prema Sukumar and Renfang Hwang as Data Science Leads.

Disclosure of Interests

Paul Emery Consultant of: AbbVie, AstraZeneca, Boehringer Ingelheim, Bristol Myers Squibb, Eli Lilly, Galapagos, Gilead, Janssen, Merck Sharp & Dohme, Novartis, Pfizer, Roche, Samsung, Grant/research support from: AbbVie, Bristol Myers Squibb, Eli Lilly, Novartis, Pfizer, Roche, Samsung, Roy Fleischmann Consultant of: Amgen, AbbVie, Bristol Myers Squibb, Gilead, GlaxoSmithKline, Novartis, Pfizer, Grant/research support from: Amgen, AbbVie, Arthrosi, Biosplice, Bristol Myers Squibb, Gilead, GlaxoSmithKline, Horizon, Novartis, Pfizer, Regeneron, TEVA, UCB, Robert Wong Shareholder of: Bristol Myers Squibb, Employee of: Bristol Myers Squibb, Karissa Lozenski Shareholder of: Bristol Myers Squibb, Employee of: Bristol Myers Squibb, Yoshiya Tanaka Speakers bureau: AbbVie, Amgen, Astellas, AstraZeneca, Boehringer Ingelheim, Bristol Myers Squibb, Chugai, Eisai, Eli Lilly, Gilead, Mitsubishi Tanabe, YL Biologics, Consultant of: AbbVie, Ayumi, Daiichi Sankyo, Eli Lilly, GlaxoSmithKline, Taisho, Sanofi, Grant/research support from: AbbVie, Asahi Kasei, Boehringer Ingelheim, Chugai, Corrona, Daiichi Sankyo, Eisai, Kowa, Mitsubishi Tanabe, Takeda, Vivian Bykerk Consultant of: Amgen, Bristol Myers Squibb, Genzyme Corporation, Gilead, Regeneron, UCB, Grant/research support from: Amgen, Bristol Myers Squibb, Genzyme Corporation, Pfizer, Regeneron, Sanofi Aventis, UCB, Clifton Bingham Consultant of: AbbVie, Bristol Myers Squibb, Eli Lilly, Janssen, Pfizer, Sanofi, Grant/research support from: Bristol Myers Squibb, Thomas Huizinga Speakers bureau: Abblynx, Abbott, Biotest AG, Bristol Myers Squibb, Crescendo Bioscience, Eli Lilly, Epirus, Galapagos, Janssen, Merck, Novartis, Pfizer, Roche, Sanofi- Aventis, UCB, Consultant of: Abblynx, Abbott, Biotest AG, Bristol Myers Squibb, Crescendo Bioscience, Eli Lilly, Epirus, Galapagos, Janssen, Merck, Novartis, Pfizer, Roche, Sanofi- Aventis, UCB, Grant/research support from: Abblynx, Abbott, Biotest AG, Bristol Myers Squibb, Crescendo Bioscience, Eli Lilly, Epirus, Galapagos, Janssen, Merck, Novartis, Pfizer, Roche, Sanofi- Aventis, UCB, Gustavo Citera Speakers bureau: AbbVie, Amgen, Bristol Myers Squibb, Eli Lilly, Janssen, Pfizer, Sandoz, Consultant of: AbbVie, Amgen, Bristol Myers Squibb, Pfizer, Grant/research support from: Pfizer, Yedid Elbez Consultant of: Bristol Myers Squibb, Employee of: Signifience, Vidya Perera Shareholder of: Bristol Myers Squibb, Employee of: Bristol Myers Squibb, Bindu Murthy Shareholder of: Bristol Myers Squibb, Employee of: Bristol Myers Squibb, Kelly Maxwell Consultant of: Bristol Myers Squibb, Employee of: Cognigen Corporation, Julie Passarell Consultant of: Bristol Myers Squibb, Employee of: Cognigen Corporation, William Hedrich: None declared, Daphne Williams Consultant of: Black Diamond Network, Joule, Syneos, Employee of: Bristol Myers Squibb.

The impact of the private sector co-payment mechanism (PSCM) on the private market for ACT in Nigeria: results of the 2018 cross-sectional outlet and household market surveys

Background

The private sector plays a large role in malaria treatment provision in Nigeria. To improve access to, and affordability of, quality-assured artemisinin-based combination therapy (QA-ACT) within this sector, the Affordable Medicines Facility-Malaria began operations in 2010 and transitioned to a private sector co-payment mechanism (PSCM) until 2017. To assess the impact of the scheme on the ACT market, cross-sectional household and outlet surveys were conducted in 2018 to coincide with the final stockages of ACT medicines procured under the PSCM.

Methods

An outlet survey was conducted targeting private pharmacies and Proprietary and Patent Medicine Vendors (PPMVs) across different regions of Nigeria to assess supply-side market factors related to availability and cost of anti-malarials, including artemisinin-based combinations subsidised under the PSCM (called green leaf ACT on account of their green leaf logo) and those not subsidised (non-green leaf ACT). A concurrent household survey was conducted to determine demand-side factors related to treatment-seeking practices, ACT brand preference and purchase decision. Data were compared with previous ACTWatch surveys to consider change over time.

Results

Availability of artemisinin-based combinations increased significantly over the PSCM period and was almost universal by the time of the 2018 market survey. This increase was seen particularly among PPMVs. While the cost of green leaf ACT remained relatively stable over time, the cost of non-green leaf ACT reduced significantly so that by 2018 they had equivalent affordability. Unsubsidised brands were also available in different formulations and dosages, with double-strength artemisinin-based combination reported as the most frequently purchased dosage type, and child artemisinin-based combinations popular in suspension and dispersible forms (forms not subsidised by the PSCM).

Conclusions

The PSCM had a clear impact on increasing not only the reach of subsidized QA brands, but also of non-subsidised brands. Increased market competition led to innovation from unsubsidised brands and large reductions in costs to make them competitive with subsidised brands. Concerns are drawn from the large market share that non-QA brands have managed to gain as well as the continued market share of oral artemisinin monotherapies. Continued monitoring of the market is recommended, along with improved local capacity for QA-certification and monitoring.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12936-021-04039-9.

A practical approach for geographic prioritization and targeting of insecticide-treated net distribution campaigns during public health emergencies and in resource-limited settings

BACKGROUND

The use of data in targeting malaria control efforts is essential for optimal use of resources. This work provides a practical mechanism for prioritizing geographic areas for insecticide-treated net (ITN) distribution campaigns in settings with limited resources.

METHODS

A GIS-based weighted approach was adopted to categorize and rank administrative units based on data that can be applied in various country contexts where Plasmodium falciparum transmission is reported. Malaria intervention and risk factors were used to rank local government areas (LGAs) in Nigeria for prioritization during mass ITN distribution campaigns. Each factor was assigned a unique weight that was obtained through application of the analytic hierarchy process (AHP). The weight was then multiplied by a value based on natural groupings inherent in the data, or the presence or absence of a given intervention. Risk scores for each factor were then summated to generate a composite unique risk score for each LGA. This risk score was translated into a prioritization map which ranks each LGA from low to high priority in terms of timing of ITN distributions.

RESULTS

A case study using data from Nigeria showed that a major component that influenced the prioritization scheme was ITN access. Sensitivity analysis results indicate that changes to the methodology used to quantify ITN access did not modify outputs substantially. Some 120 LGAs were categorized as 'extremely high' or 'high' priority when a spatially interpolated ITN access layer was used. When prioritization scores were calculated using DHS-reported state level ITN access, 108 (90.0%) of the 120 LGAs were also categorized as being extremely high or high priority. The geospatial heterogeneity found among input risk factors suggests that a range of variables and covariates should be considered when using data to inform ITN distributions.

CONCLUSION

The authors provide a tool for prioritizing regions in terms of timing of ITN distributions. It serves as a base upon which a wider range of vector control interventions could be targeted. Its value added can be found in its potential for application in multiple country contexts, expediated timeframe for producing outputs, and its use of systematically collected malaria indicators in informing prioritization.

A feasibility study to assess non-clinical community health workers' capacity to use simplified protocols and tools to treat severe acute malnutrition in Niger state Nigeria

Background

Severe acute malnutrition (SAM) is a major determinant of childhood mortality and morbidity. Although integrated community case management (iCCM) of childhood illnesses is a strategy for increasing access to life-saving treatment, malnutrition is not properly addressed in the guidelines. This study aimed to determine whether non-clinical Community Health Workers (called Community-Oriented Resource Persons, CORPs) implementing iCCM could use simplified tools to treat uncomplicated SAM.

Methods

The study used a sequential multi-method design and was conducted between July 2017 and May 2018. Sixty CORPs already providing iCCM services were trained and deployed in their communities with the target of enrolling 290 SAM cases. Competency of CORPs to treat and the treatment outcomes of enrolled children were documented. SAM cases with MUAC of 9 cm to < 11.5 cm without medical complications were treated for up to 12 weeks. Full recovery was at MUAC≥12.5 cm for two consecutive weeks. Supervision and quantitative data capturing were done weekly while qualitative data were collected after the intervention.

Results

CORPs scored 93.1% on first assessment and increment of 0.11 (95% CI, 0.05–0.18) points per additional supervision conducted. The cure rate from SAM to full recovery, excluding referrals from the denominator in line with the standard for reporting SAM recovery rates, was 73.5% and the median length of treatment was 7 weeks. SAM cases enrolled at 9 cm to < 10.25 cm MUAC had 31% less likelihood of recovery compared to those enrolled at 10.25 cm to < 11.5 cm. CORPs were not burdened by the integration of SAM into iCCM and felt motivated by children’s recovery. Operational challenges like bad terrains for supervision, supply chain management and referrals were reported by supervisors, while Government funding was identified as key for sustainability.

Conclusion

The study demonstrated that with training and supportive supervision, CORPs in Nigeria can treat SAM among under-fives, and refer complicated cases using simplified protocols as part of an iCCM programme. This approach seemed acceptable to all stakeholders, however, the effect of the extra workload of integrating SAM into iCCM on the quality of care provided by the CORPs should be assessed further.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12913-021-07118-4.

Geographical and temporal variation in reduction of malaria infection among children under 5 years of age throughout Nigeria

INTRODUCTION

Global progress in reducing malaria has stalled since 2015. Analysis of the situation is particularly needed in Nigeria, the country with by far the largest share of the burden, where approximately a quarter of all cases in the world are estimated to occur.

METHODS

We analysed data from three nationwide surveys (Malaria Indicator Surveys in 2010 and 2015 and a National Demographic and Health Survey in 2018), with malaria parasite prevalence in children under 5 years of age determined by sampling from all 36 states of Nigeria, and blood slide microscopy performed in the same accredited laboratory for all samples. Changes over time were evaluated by calculating prevalence ratio (PR) values with 95% CIs for each state, together with Mantel-Haenszel-adjusted PRs (PR_adj) for each of the six major geopolitical zones of the country.

RESULTS

Between 2010 and 2018, there were significant reductions in parasite prevalence in 25 states, but not in the remaining 11 states. Prevalence decreased most in southern zones of the country (South West PR_adj=0.53; South East PR_adj=0.59; South South PR_adj=0.51) and the North Central zone (PR_adj=0.36). Changes in the north were less marked, but were significant and indicated overall reductions by more than 20% (North-West PR_adj=0.74; North East PR_adj=0.70). Changes in the south occurred mostly between 2010 and 2015, whereas those in the north were more gradual and most continued after 2015. Recent changes were not correlated with survey-reported variation in use of preventive measures.

CONCLUSION

Reductions in malaria infection in children under 5 have occurred in most individual states in Nigeria since 2010, but substantial geographical variation in the timing and extent indicate challenges to be overcome to enable global malaria reduction.

Using the Working Model of Adjustment to Chronic Illness to explain the burden of recurrent urinary tract infection: A survey-based study

Introduction

The treatment of recurrent urinary tract infection (RUTI) with antibiotics is causing concern as patients are often prescribed an inappropriate course of antibiotics, and the recurrence rate remains at 30–44% following treatment (1). Overprescription of antibiotics can also cause antimicrobial resistance. Given the current lack of adequate clinical guidelines for RUTI treatment, it is necessary for this population to adjust to living with a chronic condition, and research suggests that RUTI may be associated with poor mental health and a lower quality of life. Thus, there is a need for a more interdisciplinary approach to understanding RUTI, to inform additional treatment options.

Aim

The current study aimed to use the Working Model of Adjustment to Chronic Illness (WMACI) (see Figure 1) to explore the personal, physical and social burden of RUTI (2).

Methods

A cross-sectional survey was employed, which was informed by existing questionnaires and reviewed by experts including pain specialists (n = 6). 5,078 participants accessed liveutifree.com to seek information regarding their condition and completed the Live UTI Free survey. Participants provided information on their experiences with RUTI (recurrence rate, symptoms, pain intensity, triggers and comorbidity) and the associated burden. Binomial logistic regressions were conducted to assess the effect of RUTI characteristics on the likelihood of experiencing personal, physical and social burden.

Results

RUTI predicted greater likelihood of personal burden (enjoyment of life; enjoyment of favourite activities; mental health) (R² = 18.8 – 20.8, p = &lt;.001), physical burden (sleep; activities of daily living; maintaining a healthy lifestyle; sexual behaviour) (R² = 21.1 – 35.9, p = &lt;.001), and social burden (normal work; finances; relationships with friends and family; relationships with partners) (R² = 17.0 - 25.8, p = &lt;.001), with the burden associated with sexual behaviour showing the largest amount of variance. Rate of recurrence, symptom burden, pain intensity, and having an additional diagnosis of Interstitial Cystitis (IC) were most predictive of participant burden.

Conclusion

RUTI was associated with all areas of burden. Some factors, including pain intensity and having an additional diagnosis of IC, affected a majority of areas. Predicted burden from having an additional diagnosis of IC may be a result of lack of clarity between the two diagnoses, which have shared symptom indicators and rely on urine culture testing, which has been demonstrated to be inaccurate. Misdiagnosis, or a dual diagnosis, may consequently contribute to burden. The WMACI was used to suggest how burden can lead to poor illness adjustment. Limitations of the study were that it did not explore the possibility of misdiagnosis and its impact, or investigate the effects of SES and country-level differences. However, the findings of the study have important clinical implications, as patients worldwide who are suffering with RUTI are required to manage significant burden that is associated with the condition, and this is an important issue which needs to be addressed in primary care settings. An interdisciplinary approach in primary care settings is recommended, which acknowledges the psychosocial burden that persists when treatment fails to resolve physical symptoms.

References

1. Gupta K, Trautner BW. Diagnosis and management of recurrent urinary tract infections in non-pregnant women. BMJ (Online). 2013; 346: f3140.

2. Moss-Morris R. Adjusting to chronic illness: Time for a unified theory. British Journal of Health Psychology. 2013; 681–686.

Effectiveness of seasonal malaria chemoprevention at scale in west and central Africa: an observational study

BACKGROUND

Seasonal malaria chemoprevention (SMC) aims to prevent malaria in children during the high malaria transmission season. The Achieving Catalytic Expansion of SMC in the Sahel (ACCESS-SMC) project sought to remove barriers to the scale-up of SMC in seven countries in 2015 and 2016. We evaluated the project, including coverage, effectiveness of the intervention, safety, feasibility, drug resistance, and cost-effectiveness.

METHODS

For this observational study, we collected data on the delivery, effectiveness, safety, influence on drug resistance, costs of delivery, impact on malaria incidence and mortality, and cost-effectiveness of SMC, during its administration for 4 months each year (2015 and 2016) to children younger than 5 years, in Burkina Faso, Chad, The Gambia, Guinea, Mali, Niger, and Nigeria. SMC was administered monthly by community health workers who visited door-to-door. Drug administration was monitored via tally sheets and via household cluster-sample coverage surveys. Pharmacovigilance was based on targeted spontaneous reporting and monitoring systems were strengthened. Molecular markers of resistance to sulfadoxine-pyrimethamine and amodiaquine in the general population before and 2 years after SMC introduction was assessed from community surveys. Effectiveness of monthly SMC treatments was measured in case-control studies that compared receipt of SMC between patients with confirmed malaria and neighbourhood-matched community controls eligible to receive SMC. Impact on incidence and mortality was assessed from confirmed outpatient cases, hospital admissions, and deaths associated with malaria, as reported in national health management information systems in Burkina Faso and The Gambia, and from data from selected outpatient facilities (all countries). Provider costs of SMC were estimated from financial costs, costs of health-care staff time, and volunteer opportunity costs, and cost-effectiveness ratios were calculated as the total cost of SMC in each country divided by the predicted number of cases averted.

FINDINGS

12 467 933 monthly SMC treatments were administered in 2015 to a target population of 3 650 455 children, and 25 117 480 were administered in 2016 to a target population of 7 551 491. In 2015, among eligible children, mean coverage per month was 76·4% (95% CI 74·0-78·8), and 54·5% children (95% CI 50·4-58·7) received all four treatments. Similar coverage was achieved in 2016 (74·8% [72·2-77·3] treated per month and 53·0% [48·5-57·4] treated four times). In 779 individual case safety reports over 2015-16, 36 serious adverse drug reactions were reported (one child with rash, two with fever, 31 with gastrointestinal disorders, one with extrapyramidal syndrome, and one with Quincke's oedema). No cases of severe skin reactions (Stevens-Johnson or Lyell syndrome) were reported. SMC treatment was associated with a protective effectiveness of 88·2% (95% CI 78·7-93·4) over 28 days in case-control studies (2185 cases of confirmed malaria and 4370 controls). In Burkina Faso and The Gambia, implementation of SMC was associated with reductions in the number of malaria deaths in hospital during the high transmission period, of 42·4% (95% CI 5·9 to 64·7) in Burkina Faso and 56·6% (28·9 to 73·5) in The Gambia. Over 2015-16, the estimated reduction in confirmed malaria cases at outpatient clinics during the high transmission period in the seven countries ranged from 25·5% (95% CI 6·1 to 40·9) in Nigeria to 55·2% (42·0 to 65·3) in The Gambia. Molecular markers of resistance occurred at low frequencies. In individuals aged 10-30 years without SMC, the combined mutations associated with resistance to amodiaquine (pfcrt CVIET haplotype and pfmdr1 mutations [86Tyr and 184Tyr]) had a prevalence of 0·7% (95% CI 0·4-1·2) in 2016 and 0·4% (0·1-0·8) in 2018 (prevalence ratio 0·5 [95% CI 0·2-1·2]), and the quintuple mutation associated with resistance to sulfadoxine-pyrimethamine (triple mutation in pfdhfr and pfdhps mutations [437Gly and 540Glu]) had a prevalence of 0·2% (0·1-0·5) in 2016 and 1·0% (0·6-1·6) in 2018 (prevalence ratio 4·8 [1·7-13·7]). The weighted average economic cost of administering four monthly SMC treatments was US$3·63 per child.

INTERPRETATION

SMC at scale was effective in preventing morbidity and mortality from malaria. Serious adverse reactions were rarely reported. Coverage varied, with some areas consistently achieving high levels via door-to-door campaigns. Markers of resistance to sulfadoxine-pyrimethamine and amodiaquine remained uncommon, but with some selection for resistance to sulfadoxine-pyrimethamine, and the situation needs to be carefully monitored. These findings should support efforts to ensure high levels of SMC coverage in west and central Africa.

FUNDING

Unitaid.

Health systems readiness and quality of inpatient malaria case-management in Kano State, Nigeria

BACKGROUND

Nigeria was among the first African countries to adopt and implement change of treatment policy for severe malaria from quinine to artesunate. Seven years after the policy change health systems readiness and quality of inpatient malaria case-management practices were evaluated in Kano State of Nigeria.

METHODS

A cross-sectional survey was undertaken in May 2019 at all public hospitals. Data collection comprised hospital assessments, interviews with inpatient health workers and data extraction from medical files for all suspected malaria patients admitted to the paediatric and medical wards in April 2019. Descriptive analyses included 22 hospitals, 154 health workers and 1,807 suspected malaria admissions analysed from malaria test and treat case-management perspective.

RESULTS

73% of hospitals provided malaria microscopy, 27% had rapid diagnostic tests and 23% were unable to perform any parasitological malaria diagnosis. Artemisinin-based combination therapy (ACT) was available at 96% of hospitals, artemether vials at 68% while injectable quinine and artesunate were equally stocked at 59% of hospitals. 32%, 21% and 15% of health workers had been exposed to relevant trainings, guidelines and supervision respectively. 47% of suspected malaria patients were tested while repeat testing was rare (7%). 60% of confirmed severe malaria patients were prescribed artesunate. Only 4% of admitted non-severe test positive cases were treated with ACT, while 76% of test negative patients were prescribed an anti-malarial. Artemether was the most common anti-malarial treatment for non-severe test positive (55%), test negative (43%) and patients not tested for malaria (45%). In all categories of the patients, except for confirmed severe cases, artemether was more commonly prescribed for adults compared to children. 44% of artesunate-treated patients were prescribed ACT follow-on treatment. Overall compliance with test and treat policy for malaria was 13%.

CONCLUSIONS

Translation of new treatment policy for severe malaria into inpatient practice is compromised by lack of malaria diagnostics, stock-outs of artesunate and suboptimal health workers' practices. Establishment of the effective supply chain and on-going supportive interventions for health workers accompanied with regular monitoring of the systems readiness and clinical practices are urgently needed.

Community engagement and mobilisation of local resources to support integrated Community Case Management of childhood illnesses in Niger State, Nigeria

Background

Despite strong evidence of integrated community case management (iCCM) of childhood illnesses being a proven intervention for reducing childhood morbidity and mortality, sustainability remains a challenge in most settings. Community ownership and contribution are important factors in sustainability. The purpose of this study was to document the process and scale achieved for community engagement and mobilisation to foster ownership, service uptake and sustainability of iCCM activities.

Methods

A review of data collected by the RAcE project was conducted to describe the scale and achievement of leveraging community resources to support the community-oriented resource persons (CORPs). The Rapid Access Expansion (RAcE)-supported iCCM programme in Niger state (2014-2017), aimed at improving coverage of case management services for malaria, pneumonia, and diarrhoea, among children aged 2–59 months. Resources donated were documented and costed based on the market value of goods and services at the time of donation. These monetary valuations were validated at community dialogue meetings. Descriptive statistics were used to summarise quantitative variables. The mean of the number of CORPs in active service and the percentages of the mobilised resources received by CORPs were calculated.

Results

The community engagement activities included 143 engagement and advocacy visits, and meetings, 300 community dialogues, reactivation of 60 ward development committees, and 3000 radio messages in support of iCCM. 79.5% of 1659 trained CORPs were still in active iCCM service at the end of the project. We estimated the costs of all support provided by the community to CORPs in cash and kind as US$ 123 062. Types of support included cash; building materials; farming support; fuel for motorcycles, and transport fares.

Conclusions

The achievements of community engagement, mobilisation, and the resources leveraged, demonstrated acceptability of the project to the beneficiaries and their willingness to contribute to uninterrupted service provision by CORPs.

Effect of community-based intervention on improving access to treatment for sick under-five children in hard-to-reach communities in Niger State, Nigeria

BACKGROUND

Access to prompt and appropriate treatment is key to survival for children with malaria, pneumonia and diarrhoea. Community-based services are vital to extending care to remote populations. Malaria Consortium supported Niger state Ministry of Health, Nigeria, to introduce and implement an integrated community case management (iCCM) programme for four years in six local government areas (LGAs). The objective was to increase coverage of effective treatment for malaria, pneumonia and diarrhoea among children aged 2-59 months.

METHODS

The programme involved training, equipping, ongoing support and supervision of 1320 community volunteers (CORPs) to provide iCCM services to their communities in all six LGAs. Demand creation activities were also conducted; these included community dialogues, household mobilization, sensitization and mass media campaigns targeted at programme communities. To assess the level of changes in care seeking and treatment, baseline and endline household surveys were conducted in 2014 and 2017 respectively. For both surveys, a 30×30 multi-stage cluster sampling method was used, the sampling frame being RAcE programme communities.

RESULTS

Care-seeking from an appropriate provider increased overall and for each iCCM illness from 78% to 94% for children presenting with fever (P < 0.01), from 72% to 91% for diarrhoea cases (P < 0.01), and from 76% to 89% for cases of cough with difficult or fast breathing (P < 0.05). For diagnosis and treatment, the coverage of fevers tested for malaria increased from 34% to 77% (P < 0.001) and ACT treatments from 57% to 73% (<0.005); 56% of cases of cough or fast breathing who sought care from a CORP, had their respiratory rate counted and 61% with cough or fast breathing received amoxicillin. At endline caregivers sought care from CORPs in their communities for most cases of childhood illnesses (84%) compared to other providers at hospitals (1%) or health centres (9%).This aligns with caregivers' belief that CORPs are trusted providers (94%) who provide quality services (96%).

CONCLUSION

Implementation of iCCM with focused demand creation activities can improve access to quality lifesaving interventions from frontline community providers in Nigeria. This can contribute towards achieving SDGs if iCCM is scaled up to hard-to-reach areas of all states in the country.

Abstract PD8-04: Evolutionary history and genomic landscape of metastatic breast cancer

Background: The majority of deaths from breast cancer are due to distant metastatic disease. Despite this, few systematic genomic analyses have been performed on metastatic tumors. This results from the relative difficulty of performing biopsies on metastatic tumors, as well as the uncertainty regarding genomic determinism, according to which the majority of actionable mutations present in metastases can be discovered in the primary tumor.

Methods: “METAMORPH” is an ongoing prospective cohort study of women with suspected or confirmed recurrent breast cancer enrolled prior to starting a new therapy for recurrent metastatic disease. Biopsies of metastatic lesions were performed under radiologic guidance, and archival primary tumors were subsequently obtained. WES and sWGS were performed to determine coding mutations and aberrant copy-number in metastatic tumors from 67 patients, 33 of which were assayed with corresponding matched primary tumors.

Results: Using Bayesian approaches, we find that cancers fit one of two patterns: canonical linear evolution (whereby the metastatic tumor arises from one or more advanced primary tumor subclones) vs. branched evolution (whereby both primary and metastatic tumors develop mutations that go on to become clonal within their respective tumors after the time of dissemination). In cases where tumors show evidence of branched evolution or small subclone dissemination, we expect that a large proportion of mutations may not be represented in both the primary and corresponding metastatic tumors. Indeed, primary-metastatic tumor pairs show substantial discordance at the genomic level, sharing only ˜30% of mutations and ˜28% of copy-number alterations on average. Furthermore, we find that metastatic tumors have decreased clonal heterogeneity, suggesting a history of selection. Indeed, we find clinically relevant mutations that are present exclusively in the primary or the corresponding recurrent metastatic tumor, as well as genes that are recurrently altered in metastatic tumors, such as amplification of SRC-1, loss of genes encoding CDK inhibitors, and alterations in JAK1/2/3.Finally, compared to the primary tumors from which they arose, metastatic tumors exhibit increased frequencies of alterations in several discrete pathways, including those involving the extracellular matrix as well as PI3K/AKT/mTOR, estrogen, and HER2 signaling.

Conclusions: The low degree of genomic concordance between primary and metastatic tumors due to evolutionary distance, as well as the presence of activating and targetable mutations specifically in metastatic tumors, suggests that there is value in comprehensively characterizing metastatic tumors to inform patient treatment and identify novel targets underlying breast cancer progression.

Citation Format: Paul MR, Pan T-C, Pant D, Belka GK, Chen Y, Shih N, Lieberman D, Morrissette JJD, Soucier-Ernst D, Clark C, Stavropoulos W, Maxwell K, Feldman M, DeMichele A, Chodosh LA. Evolutionary history and genomic landscape of metastatic breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr PD8-04.

Health worker perspectives on the possible use of intramuscular artesunate for the treatment of severe malaria at lower-level health facilities in settings with poor access to referral facilities in Nigeria: a qualitative study

Background

Innovative strategies are needed to reduce malaria mortality in high burden countries like Nigeria. Given that one of the important reasons for this high malaria mortality is delay in receiving effective treatment, improved access to such treatment is critical. Intramuscular artesunate could be used at lower-level facilities given its proven efficacy, ease of use and excellent safety profile. The objective of this study was therefore to explore health workers’ perspectives on the possible use of intramuscular artesunate as definitive treatment for severe malaria at lower-level facilities, especially when access to referral facilities is challenging. The study was to provide insight as a formative step into the conduct of future experimental studies to ascertain the feasibility of the use of intramuscular artesunate for definitive treatment of severe malaria in lower level facilities where access to referral care is limited.

Methods

This qualitative study was done across three southern States in Nigeria (Oyo, Cross River and Enugu). Key informant interviews were conducted over a period of three months between October and December 2014 among 90 purposively selected health workers with different roles in malaria case management from primary care to policy level. A thematic content analysis was used to analyse data.

Results

Overall, most of health workers and other key informant groups thought that the use of intramuscular artesunate for definitive treatment of severe malaria at lower-level facilities was possible. They however reported human resource and infrastructure constraints as factors affecting the feasibility of intramuscular artesunate use as definitive treatment for severe malaria in lower-level facilities.. Specifically identified barriers included limited numbers of skilled health workers available to manage potential complications of severe malaria and poorly equipped facilities for supportive treatment. Intramuscular artesunate was considered easy to administer and the proximity of lower-level facilities to communities was deemed important in considering the possibility of its use at lower-level facilities. Health workers also emphasised the important role of operational research to provide additional evidence to guide the implementation of existing policy recommendations and inform future policy revisions.

Conclusions

From the perspective of health workers, use of intramuscular artesunate for definitive treatment of severe malaria at lower-level health facilities in Nigeria is possible but dependent on availability of skilled workers, well-equipped lower-level facilities to provide supportive treatment There is need for further operational research to establish feasibility and guide the implementation of such an intervention.

Electronic supplementary material

The online version of this article (doi:10.1186/s12913-016-1811-x) contains supplementary material, which is available to authorized users.

Hydrophobic trichome layers and epicuticular wax powders in Bromeliaceae

The distinctive foliar trichome of Bromeliaceae has promoted the evolution of an epiphytic habit in certain taxa by allowing the shoot to assume a significant role in the uptake of water and mineral nutrients. Despite the profound ecophysiological and taxonomic importance of this epidermal structure, the functions of nonabsorbent trichomes in remaining Bromeliaceae are not fully understood. The hypothesis that light reflection from these trichome layers provides photoprotection was not supported by spectroradiometry and fluorimetry in the present study; the mean reflectance of visible light from trichome layers did not exceed 6.4% on the adaxial surfaces of species representing a range of ecophysiological types nor was significant photoprotection provided by their presence. Several reports suggesting water repellency in some terrestrial Bromeliaceae were investigated. Scanning electron microscopy (SEM) and a new technique-fluorographic dimensional imaging (FDI)-were used to assess the interaction between aqueous droplets and the leaf surfaces of 86 species from 25 genera. In the majority of cases a dense layer of overlapping, stellate or peltate trichomes held water off the leaf epidermis proper. In the case of hydrophobic tank-forming tillandsioideae, a powdery epicuticular wax layer provided water repellency. The irregular architecture of these indumenta resulted in relatively little contact with water droplets. Most mesic terrestrial Pitcairnioideae examined either possessed glabrous leaf blades or hydrophobic layers of confluent trichomes on the abaxial surface. Thus, the present study indicates that an important ancestral function of the foliar trichome in Bromeliaceae was water repellency. The ecophysiological consequences of hydrophobia are discussed.

Importance of specific nucleotides in the folding of the natural form of the hairpin ribozyme

The hairpin ribozyme in its natural context consists of two loops in RNA duplexes that are connected as arms of a four-way helical junction. Magnesium ions induce folding into the active conformation in which the two loops are in proximity. In this study, we have investigated nucleotides that are important to this folding process. We have analyzed the folding in terms of the cooperativity and apparent affinity for magnesium ions as a function of changes in base sequence and functional groups, using fluorescence resonance energy transfer. Our results suggest that the interaction between the loops is the sum of a number of component interactions. Some sequence variants such as A10U, G+1A, and C25U exhibit loss of cooperativity and reduced affinity of apparent magnesium ion binding. These variants are also very impaired in ribozyme cleavage activity. Nucleotides A10, G+1, and C25 thus appear to be essential in creating the conformational environment necessary for ion binding. The double variant G+1A/C25U exhibits a marked recovery of both folding and catalytic activity compared to either individual variant, consistent with the proposal of a triple-base interaction among A9, G+1, and C25 [Pinard, R., Lambert, D., Walter, N. G., Heckman, J. E., Major, F., and Burke, J. M. (1999) Biochemistry 38, 16035-16039]. However, substitution of A9 leads to relatively small changes in folding properties and cleavage activity, and the double variant G+1DAP/C25U (DAP is 2,6-diaminopurine), which could form an isosteric triple-base interaction, exhibits folding and cleavage activities that are both very impaired compared to those of the natural sequence. Our results indicate an important role for a Watson--Crick base pair between G+1 and C25; this may be buttressed by an interaction with A9, but the loss of this has less significant consequences for folding. 2'-Deoxyribose substitution leads to folding with reduced magnesium ion affinity in the following order: unmodified RNA > dA9 > dA10 > dC25 approximately dA10 plus dC25. The results are interpreted in terms of an interaction between the ribose ring of C25 and the ribose and base of A10, in agreement with the proposal of Ryder and Strobel [Ryder, S. P., and Strobel, S. A. (1999) J. Mol. Biol. 291, 295-311]. In general, there is a correlation between the ability to undergo ion-induced folding and the rate of ribozyme cleavage. An exception to this is provided by G8, for which substitution with uridine leads to severe impairment of cleavage but folding characteristics that are virtually unaltered from those of the natural species. This is consistent with a direct role for the nucleobase of G8 in the chemistry of cleavage.

The folding of the hairpin ribozyme: dependence on the loops and the junction

In its natural context, the hairpin ribozyme is constructed around a four-way helical junction. This presents the two loops that interact to form the active site on adjacent arms, requiring rotation into an antiparallel structure to bring them into proximity. In the present study we have compared the folding of this form of the ribozyme and subspecies lacking either the loops or the helical junction using fluorescence resonance energy transfer. The complete ribozyme as a four-way junction folds into an antiparallel structure by the cooperative binding of magnesium ions, requiring 20-40 microM for half-maximal extent of folding ([Mg2+]1/2) and a Hill coefficient n = 2. The isolated junction (lacking the loops) also folds into a corresponding antiparallel structure, but does so noncooperatively (n = 1) at a higher magnesium ion concentration ([Mg2+]1/2 = 3 mM). Introduction of a G + 1A mutation into loop A of the ribozyme results in a species with very similar folding to the simple junction, and complete loss of ribozyme activity. Removal of the junction from the ribozyme, replacing it either with a strand break (serving as a hinge) or a GC5 bulge, results in greatly impaired folding, with [Mg2+]1/2 > 20 mM. The results indicate that the natural form of the ribozyme undergoes ion-induced folding by the cooperative formation of an antiparallel junction and loop-loop interaction to generate the active form of the ribozyme. The four-way junction thus provides a scaffold in the natural RNA that facilitates the folding of the ribozyme into the active form.

Chlorophyll fluorescence--a practical guide

Chlorophyll fluorescence analysis has become one of the most powerful and widely used techniques available to plant physiologists and ecophysiologists. This review aims to provide an introduction for the novice into the methodology and applications of chlorophyll fluorescence. After a brief introduction into the theoretical background of the technique, the methodology and some of the technical pitfalls that can be encountered are explained. A selection of examples is then used to illustrate the types of information that fluorescence can provide.

Chlorophyll fluorescence--a practical guide

Chlorophyll fluorescence analysis has become one of the most powerful and widely used techniques available to plant physiologists and ecophysiologists. This review aims to provide an introduction for the novice into the methodology and applications of chlorophyll fluorescence. After a brief introduction into the theoretical background of the technique, the methodology and some of the technical pitfalls that can be encountered are explained. A selection of examples is then used to illustrate the types of information that fluorescence can provide.

Glucose uptake increases relative to oxygen consumption during short-term hibernation

BACKGROUND

Although glucose uptake is increased in chronically hypoperfused, viable myocardium, the dynamic changes in glucose uptake relative to oxygen consumption in "short-term" models of hibernation have not been fully explored.

METHODS

14 anesthetized swine were instrumented with an hydraulic occluder and flow probe on the proximal LAD artery. Blood flow was reduced approximately 30% for 1 hour. Myocardial blood flow and uptake of oxygen, free fatty acids, glucose and lactate were determined in the LAD region at baseline and at 10, 30, and 60 minutes of ischemia. Transmural biopsies for ATP and creatine phosphate (CP) were obtained in the LAD region prior to and at 15 and 45 minutes of ischemia. In 5 animals, glycogen was assayed at baseline and at the end of 60 minutes of ischemia.

RESULTS

In the LAD region, myocardial oxygen consumption was reduced from 2.06 +/- 0.16 micromol/min/gram to 1.46 +/- 0.13 micromol/min/gram (P < 0.05). By 15 minutes of ischemia, transmural creatine phosphate fell from 7.48 +/- 0.76 micromol/g-wet weight at baseline to 6.19 +/- 0.32 micromol/g-wet weight (P < 0.05) but normalized by 45 minutes of ischemia (7.39 +/- 0.56 micromol/g-wet weight; NS). Between 10 and 60 minutes of constant flow reduction, glucose uptake as a percentage of MVO2 increased from 3 +/- 2% to 10 +/- 2% (P < 0.05) while lactate uptake increased from -9 +/- 9% to -1 +/- 2% (P < 0.05). Glycogen decreased from 27.8 +/- 3.7 at baseline to 16.9 +/- 1.2 micromol/g-wet weight at end-ischemia.

CONCLUSIONS

In this model of short-term hibernation, glucose and lactate uptake increase relative to oxygen consumption during sustained ischemia, and temporally coincide with the recovery of bioenergetics. The findings are consistent with the notion that glycolytically derived ATP is important for the maintainance of energy supply during sustained ischemia.

Functional role of ionic regulation of Na+/Ca2+ exchange assessed in transgenic mouse hearts

Na+/Ca2+ exchange is the primary mechanism mediating Ca2+ efflux from cardiac myocytes during diastole and, thus, can prominently influence contractile force. In addition to transporting Na+ and Ca2+, the exchanger is also regulated by these ions. Although structure-function studies have identified protein regions of the exchanger subserving these regulatory processes, their physiological importance is unknown. In this study, we examined the electrophysiological and mechanical consequences of cardiospecific overexpression of the canine cardiac exchanger NCX1.1 and a deletion mutant of NCX1.1 (Delta680-685), devoid of intracellular Na+ (Na+i)- and Ca2+ (Ca2+i)- dependent regulatory properties, in transgenic mice. Using the giant excised patch-clamp technique, normal ionic regulation was observed in membrane patches from cardiomyocytes isolated from control and transgenic mice overexpressing NCX1.1. In contrast, ionic regulation was nearly abolished in mice overexpressing Delta680-685, indicating that the native regulatory processes could be overwhelmed by expression of the transgene. To address the physiological consequences of ionic regulation of the Na+/Ca2+ exchanger, we examined postrest force development in papillary muscles from NCX1.1 and Delta680-685 transgenic mice. Postrest potentiation was found to be substantially greater in Delta680-685 than in NCX1.1 transgenic mice, supporting the notion that ionic regulation of Na+/Ca2+ exchange plays a significant functional role in cardiac contractile properties.

Experiences of hospital care and treatment-seeking behavior for pain from sickle cell disease: qualitative study

OBJECTIVE

To investigate how sociocultural factors influence the management of pain from sickle cell disease by comparing the experiences of those who usually manage their pain at home with the experiences of those who are more frequently admitted to hospital for management of their pain.

DESIGN

Qualitative analysis of semistructured individual interviews and focus group discussions.

PARTICIPANTS

57 participants with genotype SS or S/beta-thal (44 participants) or SC (9 participants); the status of 4 participants was unknown. 40 participants took part in focus groups, 6 took part in both focus groups and interviews, and 9 were interviewed only. Participants were allocated to focus groups according to ethnic origin, sex, and the number of times that they had been admitted to the hospital for the management of painful crises during the previous year.

RESULTS

The relation between patients with sickle cell disease and hospital services is one of several major, nonclinical dimensions that shape experiences of pain management and behavior for seeking health care. Participants' experiences of hospital care show a range of interrelated themes that are common to most participants across variables of sex, ethnicity, and which hospital was attended. Themes identified included the mistrust of patients with sickle cell disease, stigmatization, excessive control (including both overtreatment and undertreatment of pain) and neglect. Individuals responded to the challenge of negotiating care with various strategies. Patients with sickle cell disease who are frequently admitted to hospital may try to develop long-term relationships with their caregivers, become passive or aggressive in their interactions with health professionals, or regularly attend different hospitals. Those who usually manage their pain at home expressed a strong sense of responsibility for the management of their pain and advocated self-education, assertiveness, and resistance as strategies toward hospital services.

CONCLUSIONS

The organization and delivery of management for the pain of a sickle cell crisis discourages self-reliance and encourages hospital dependence. Models of care should recognize the chronic nature of sickle cell disorders and give priority to patients' involvement in their care.

Chloroplast acclimation in leaves of Guzmania monostachia in response to high light

Acclimation of leaves to high light (HL; 650 micromol m(-2) s(-1)) was investigated in the long-lived epiphytic bromeliad Guzmania monostachia and compared with plants maintained under low light (LL; 50 micromol m(-2) s(-1)). Despite a 60% decrease in total chlorophyll in HL-grown plants, the chlorophyll a/b ratio remained stable. Additionally, chloroplasts from HL-grown plants had a much lower thylakoid content and reduced granal stacking. Immunofluorescent labeling techniques were used to quantify the level of photosynthetic polypeptides. HL-grown plants had 30% to 40% of the content observed in LL-grown plants for the light-harvesting complex associated with photosystems I and II, the 33-kD photosystem II polypeptide, and Rubisco. These results were verified using conventional biochemical techniques, which revealed a comparable 60% decrease in Rubisco and total soluble protein. When expressed on a chlorophyll basis, the amount of protein and Rubisco was constant for HL- and LL-grown plants. Acclimation to HL involves a tightly coordinated adjustment of photosynthesis, indicating a highly regulated decrease in the number of photosynthetic units manifested at the level of the content of light-harvesting and electron transport components, the amount of Rubisco, and the induction of Crassulacean acid metabolism. This response occurs in mature leaves and may represent a strategy that is optimal for the resource-limited epiphytic niche.

Risperidone-induced hepatotoxicity in children and adolescents? A chart review study

Risperidone is an atypical antipsychotic drug that has been used in the treatment of numerous psychiatric disorders in children and adolescents. The question of whether risperidone-induced weight gain is associated with steatohepatitis has recently been raised. The purpose of this chart review was to ascertain: (1) the rate of liver dysfunction observed during risperidone treatment in children and adolescents; and (2) the clinical factors associated with liver dysfunction. For purposes of this chart review study, abnormal liver function was defined by serum transaminase or bilirubin values falling outside the normal laboratory ranges. Chart reviews were completed on 38 youths with ages ranging from 5-17 years with a variety of psychiatric diagnoses. The mean length of risperidone treatment was 15.2 months at a mean dose of 2.5 mg/day. It was found that 37 of the 38 youths treated with risperidone had no liver enzyme abnormalities at the end of study. One subject had an alanine aminotransferase (ALT) level of 46 U/L which was 7 U/L above the upper limit of normal for this laboratory test. This isolated value was not considered clinically significant. These data were noted in spite of weight gain and the use of numerous concomitant psychotropic medications. These findings suggest that risperidone in short term treatment does not commonly lead to evidence of abnormal liver function at therapeutic doses in children and adolescents. Larger-scale, prospective studies are needed in order to confirm these findings.

Experiences of hospital care and treatment seeking for pain from sickle cell disease: qualitative study

OBJECTIVE

To investigate how sociocultural factors influence management of pain from sickle cell disease by comparing the experiences of those who usually manage their pain at home with those who are more frequently admitted to hospital for management of their pain.

DESIGN

Qualitative analysis of semistructured individual interviews and focus group discussions.

PARTICIPANTS

57 participants with genotype SS or S/beta-thal (44 subjects) or SC (9) (4 were unknown). 40 participants took part in focus groups, six took part in both focus groups and interviews, and nine were interviewed only. Participants were allocated to focus groups according to number of hospital admissions for painful crisis management during the previous year, ethnic origin, and sex.

RESULTS

The relation between patients with sickle cell disease and hospital services is one of several major non-clinical dimensions shaping experiences of pain management and behaviour for seeking health care. Experiences of hospital care show a range of interrelated themes, which are common to most participants across variables of sex, ethnicity, and hospital attended: mistrust of patients with sickle cell disease; stigmatisation; excessive control (including both over- and undertreatment of pain); and neglect. Individuals respond to the challenge of negotiating care with various strategies. Patients with sickle cell disease who are frequently admitted to hospital may try to develop long term relationships with their carers, may become passive or aggressive in their interactions with health professionals, or may regularly attend different hospitals. Those individuals who usually manage their pain at home express a strong sense of self responsibility for their management of pain and advocate self education, assertiveness, and resistance as strategies towards hospital services.

CONCLUSIONS

The current organisation and delivery of management of pain for sickle cell crisis discourage self reliance and encourage hospital dependence. Models of care should recognise the chronic nature of sickle cell disorders and prioritise patients' involvement in their care.

Structure-function analysis of CALX1.1, a Na+-Ca2+ exchanger from Drosophila. Mutagenesis of ionic regulatory sites

Cytoplasmic Na+ and Ca2+ regulate the activity of Na+-Ca2+ exchange proteins, in addition to serving as the transported ions, and protein regions involved in these processes have been identified for the canine cardiac Na+-Ca2+ exchanger, NCX1.1. Although protein regions associated with Na+i- and Ca2+i-dependent regulation are highly conserved among cloned Na+-Ca2+ exchangers, it is unknown whether or not the structure-function relationships characteristic of NCX1.1 apply to any other exchangers. Therefore, we studied structure-function relationships in a Na+-Ca2+ exchanger from Drosophila, CALX1.1, which is unique among characterized members of this family of proteins in that microM levels of Ca2+i inhibit exchange current. Wild-type and mutant CALX1.1 exchangers were expressed in Xenopus oocytes and characterized electrophysiologically using the giant excised patch technique. Mutations within the putative regulatory Ca2+i binding site of CALX1. 1, like corresponding alterations in NCX1.1, led to reduced ability (i.e. D516V and D550I) or inability (i.e. G555P) of Ca2+i to inhibit Na+-Ca2+ exchange activity. Similarly, mutations within the putative XIP region of CALX1.1, as in NCX1.1, led to two distinct phenotypes: acceleration (i.e. K306Q) and elimination (i.e. Delta310-313) of Na+i-dependent inactivation. These results indicate that the respective regulatory roles of the Ca2+i binding site and XIP region are conserved between CALX1.1 and NCX1.1, despite opposite responses to Ca2+i. We extended these findings using chimeric constructs of CALX1.1 and NCX1.1 to determine whether or not functional interconversion of Ca2+i regulatory phenotypes was feasible. With one chimera (i.e. CALX:NCX:CALX), substitution of a 193-amino acid segment, from the large intracellular loop of NCX1.1, for the corresponding 177-amino acid segment of CALX1.1 led to an exchanger that was stimulated by Ca2+i. This result indicates that the regulatory Ca2+i binding site of NCX1.1 retains function in a CALX1. 1 parent transporter and that the substituted segment contains some of the amino acid sequence(s) required for transduction of the Ca2+i binding signal.

Biology and function of the reversible sulfation pathway catalysed by human sulfotransferases and sulfatases

Sulfation and sulfate conjugate hydrolysis play an important role in metabolism, and are catalysed by members of the sulfotransferase and sulfatase enzyme super-families. In general, sulfation is a deactivating, detoxication pathway, but for some chemicals the sulfate conjugates are much more reactive than the parent compound. The range of compounds which are sulfated is enormous, yet we still understand relatively little of the function of this pathway. This review summarises current knowledge of the sulfation system and the enzymes involved, and illustrates how heterologous expression of sulfotransferases (SULTs) and sulfatases is aiding our appreciation of the properties of these important proteins. The role of sulfation in the bioactivation of procarcinogens and promutagens is discussed, and new data on the inhibition of the sulfotransferase(s) involved by common dietary components such as tea and coffee are presented. The genetic and environmental factors which are known to influence the activity and expression of human SULTs and sulfatases are also reviewed.

Laser-cured fibrinogen glue to repair bleb leaks in rabbits

OBJECTIVE

To determine whether laser-cured fibrinogen glue can close bleb leaks in rabbits.

METHODS

Full-thickness filtration surgery with intraoperative mitomycin and a sutured limbus-based conjunctival flap was performed in 1 eye each of 19 New Zealand albino rabbits. On the second postoperative day, a 2- to 3-mm hole was made in the bleb. In 9 rabbits, the hole was glued using fibrinogen glue with indocyanine green dye added. The glue was "cured" with a diode laser. Eyes that had been glued and developed a subsequent leak had the glue reapplied on the day the leak was detected.

RESULTS

The glue remained on the conjunctiva for an average (mean+/-SD) of 1.9+/-1.8 days (range, 0-5 days). The last day of bleb leak for the rabbits with glued eyes was 1.6+/-2.4 days; for the control rabbits, it was 8.0+/-4.4 days (P=.001, Mann-Whitney U test).

CONCLUSION

Laser-cured fibrinogen glue is effective in closing bleb leaks in rabbits.

Endoscopic creation of reflux in the pig

Vesicoureteral reflux (VUR) in the animal model for experimental purposes can be created either by open transvesical or endoscopic techniques. The concept of reflux creation is the same for both techniques: incision of the roof of the intramural portion of the ureter at the 12 o'clock position. The open method has the disadvantages of requiring a cystotomy and a lengthy healing period prior to initiating a study, thereby incurring additional expense and the problem of introducing several confounding factors. The open method is unreliable because of the resolution of reflux over time. Herein, we present a simple transurethral endoscopic technique for creating VUR in pigs. This technique was successful in producing persistent Grade II or III reflux in 94% of the incised ureters.

Not a 'proper' solution? The gap between professional guidelines and users' views about the safety of using emergency contraception

OBJECTIVES

As a form of contraception which is used after sex, emergency contraception occupies a singular place in the birth control repertoire. The relatively high UK incidence of pregnancy terminations and of teenage pregnancy, combined with the recognition that much early sex remains unplanned and unprotected, has led to calls for better access to emergency contraceptive methods. In this study a combination of self-completion questionnaires and semi-structured interviews was used to explore views of emergency contraception among women who were using the method.

METHODS

Five hundred and ten women attending two family planning clinics in Oxford and London completed a questionnaire in the waiting room and 53 women who were attending for emergency contraception took part in semi-structured interviews.

RESULTS

The view, presented in recently published UK guidelines, that emergency contraception is a reliable method and not dangerous to repeat, was not shared by the respondents. The rationale for and sources of women's concerns about the strength of the dose of hormonal emergency contraception and the nature of side-effects are explored.

Cytokine expression in otitis media with effusion. Tumor necrosis factor soluble receptor

BACKGROUND

A variety of cytokines, such as interleukin 1 and tumor necrosis factor (TNF), appear to play a key role in the initiation and maintenance of the inflammatory response in a variety of diseases, including chronic otitis media with effusion (COME). Recently, cytokine inhibitors have been isolated and are presumed to regulate the proinflammatory effects of these cytokines. This has lead us to hypothesize that the chronic inflammation seen in COME is the result of an imbalance in the ratio of proinflammatory cytokines and inhibitors that favors the proinflammatory cytokines.

DESIGN

Middle ear effusions were evaluated for the cytokine TNF-alpha and the inhibitor TNF soluble receptor (TNFsolR) using a combination of enzyme-linked immunosorbent assays and radioactive immunoassays. We determined the presence and quantified the amounts of TNF-alpha and TNFsolR and correlated this result with clinical parameters in patients with COME.

SETTING

University hospital.

PATIENTS

To test this hypothesis, 35 middle ear effusions were obtained from 29 children aged 2 to 102 months (mean, 39.6 months) undergoing tympanostomy tube insertion for COME.

OUTCOME

Children were followed up for at least 12 months postoperatively and the number of subsequent episodes of otitis media correlated with cytokine levels.

RESULTS

The TNF-alpha and TNFsolR were present in 83% and 91% of effusions, respectively. The TNF-alpha mean (+/-SEM) cytokine values were 110.6 +/- 32.1 pg/mg of total protein, and 12886 +/- 3108 pg/mg total protein for TNFsolR. Analysis of correlations in a univariate model revealed a statistically significant relationship for TNF-alpha correlated with TNFsolR (R2 = 0.463; P < .001). The TNF-alpha levels were significantly lower for children with multiple tube insertions (P = .02). Higher levels of TNF-alpha were noted in those children who subsequently developed episodes of otitis media after tube placement (P = .02). The ratio of TNF-alpha to TNFsolR, the mean (+/-SEM) inhibitor index was 430 +/- 220 U.

CONCLUSIONS

Our data support the hypothesis that cytokines and their inhibitors are present in a large number of middle ear effusions and in part are likely important in the regulation of inflammatory processes in COME.

High-dose pyridoxine and magnesium administration in children with autistic disorder: an absence of salutary effects in a double-blind, placebo-controlled study

Several reports have described salutary effects such as decreased physical aggression and improved social responsiveness being associated with the administration of high doses of pyridoxine and magnesium (HDPM) in open-labeled and controlled studies of patients with autism. Despite this fact, this intervention remains controversial. A 10-week double-blind, placebo-controlled trial was undertaken to examine both the efficacy and safety of HDPM in autism. Twelve patients were enrolled, and 10 patients (mean age 6 years 3 months) were able to complete the study. HDPM at an average dose of 638.9 mg of pyridoxine and 216.3 mg of magnesium oxide was ineffective in ameliorating autistic behaviors as assessed by the Children's Psychiatric Rating Scale (CPRS), the Clinical Global Impression Scale, and the NIMH Global Obsessive Compulsive Scale. Furthermore, no clinically significant side effects were noted during HDPM administration. A trend for a transient change on the CPRS was found that was possibly due to a placebo response. This study raises doubts about the clinical effectiveness of HDPM in autistic disorder.

The effect of changing the total parenteral nutrition order form on resident physician ordering behavior

The quality assurance process at Scott and White Hospital, Temple, Texas, identified a marked variation in total parenteral nutrition (TPN) prescriptions compared with recommendations by the Nutrition Support Service (NSS). A TPN order form with additive guidelines was designed to assist physicians in ordering TPN specific to patient needs. The effect of the change was assessed by comparing 50 TPN patients using the old form (1990) with 50 patients for whom the new form (1992) was used. The groups demonstrated no difference in demographics, mortality, length of stay, or biochemical parameters and were reflective of all TPN patients treated (1990, n = 280; 1992, n = 392). A significant decrease was noted in overfeeding of kilocalories when resident orders were compared with NSS recommendations (125% +/- 24% versus 110% +/- 29%, p = .017; and amino acids (120% +/- 32% versus 105% +/- 29%, p = .071, mean +/- SD). This resulted in a decrease of 8% in the cost of delivering a patient-day of TPN. We conclude that changing the TPN order form to a teaching vehicle results in decreased overfeeding and costs.

An open clinical trial of risperidone monotherapy in young children with autistic disorder

Autistic disorder (AD) may be associated with dysfunctional behaviors which significantly interfere with a child's functioning. Risperidone has been described as having salutary effects as an adjunctive pharmacotherapy in adult and pediatric patients with AD. The purpose of this 8-week, open-label study was to examine the effectiveness and tolerability of risperidone monotherapy in young patients with AD. Doses of risperidone were to be started at 0.25 mg qhs and were titrated to maximize clinical efficacy. Six patients (ages 5 to 9 years) were enrolled in this protocol, and all completed it. After 8 weeks of treatment, with a mean risperidone dose of 1.1 mg, improvement in symptomatology was demonstrated by reduced scores on both the Children's Psychiatric Rating Scale (p < .005) and the Clinical Global Impressions Scale (p < .001). The most common side effect were weight gain and sedation. This study provides preliminary evidence that risperidone monotherapy may be safe and effective in ameliorating dysfunctional behaviors in children with AD.

Murine model of otitis media with effusion: immunohistochemical demonstration of IL-1 alpha antigen expression

Recent studies have suggested that cytokines likely play a central role in the formation and maintenance of otitis media with effusion (OME). Currently, there is no immunologically defined animal model for the study of cytokines as they contribute to the formation of OME. In the present study, a murine model of OME, using eustachian tube blockage via an external surgical approach, was developed. The murine model temporal bone histology appears to mimic the histology found in chronic otitis media with effusion in humans. Additionally, using this murine model, interleukin-1 alpha (IL-1 alpha) expression was detected in the middle ear using standard immunohistochemical techniques. IL-1 alpha seemed localized to the epithelial lining of the middle ear as well as 5% to 10% of inflammatory cells. This model should provide the necessary tool to further study the immunologic aspects of OME.

Effects of weight training on the emotional well-being and body image of females: predictors of greatest benefit

BACKGROUND

This study was conducted to determine the extent to which participation in a weight training intervention was associated with changes in the emotional well-being and body image of females compared to non-weight trainers. An ancillary objective was to study the extent to which psychological, physical, and demographic factors accounted for changes in emotional well-being and body image.

METHODS

The experimental group consisted of 60 females, and a comparison group was comprised of 92 females. Experimental subjects participated in a 15-week, two-day-per-week weight training intervention, while subjects in the comparison group did not participate in any weight training activities. Subjects were pre- and posttested on the General Well-Being Schedule and the Body Cathexis Scale. Experimental subjects were also tested in muscular strength and three skinfold measurements.

RESULTS

With pretest scores controlled, the weight trainers had significantly higher General Well-Being and Body Cathexis posttest scores than the comparison group. Weight trainers also showed significant increases in muscular strength, and significant decreases in skinfold thickness. Four variables predicted 38.8% of the variance of those who improved most in General Well-Being: lower pretest General Well-Being, lower parental income, greater loss of body weight, and lower posttest skinfold. Five variables predicted 61.5% of the variance of those women who improved most in Body Cathexis: lower pretest Body Cathexis, greater body weight at the outset, shorter in height, less involvement in non-weight training exercise, and lower posttest skinfold.

DISCUSSION

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Beta-VLDL increases endothelial cell plasma membrane cholesterol

In this study, the distribution of free cholesterol in cholesterol-loaded endothelial cells was examined. For these studies, cell fractionation methods were used to assess marker enzyme activity and cholesterol distribution. Treatment of rabbit aortic endothelial cells for 3 days with 50 micrograms/ml of beta-very low density lipoprotein (beta-VLDL) or malondialdehyde-low density lipoprotein (MDA-LDL) but not LDL caused a 50-100% increase in total cell unesterified cholesterol. The accumulation of free rather than esterified cholesterol in endothelial cells may be due to the ratio of hydrolysis to esterification, which we have shown in this study to be 10-fold higher in endothelial cells than in smooth muscle cells. This free cholesterol is found in the fractions enriched in plasma membrane markers and, to a lesser extent, in the Golgi-enriched fractions. The amount of cholesterol per mg of protein was increased approximately 50% in these fractions from cells treated for 3 days with 50 micrograms/ml of beta-VLDL. These increases in cholesterol content were reversible upon incubation of cells for 3 days in medium containing 15% fetal bovine serum. Alterations in several membrane functions were also observed in cholesterol-loaded cells. The activity of alkaline phosphatase, an enzyme marker for plasma membranes, was decreased by 25% and an alteration in membrane-associated microfilaments was seen with phalloidin staining. This morphological change in microfilaments was reflected in a decrease in filament ends as shown by cytochalasin binding and occurred without a change in total actin or vinculin. These microfilament changes were reversible.(ABSTRACT TRUNCATED AT 250 WORDS)

Medical students' knowledge, attitudes, and behavior concerning diet and heart disease

Demand for physician-based dietary treatment of hypercholesterolemia is increasing, but medical care providers feel that they lack the skills and confidence necessary to provide these services. Using a self-administered questionnaire, we studied the relationships among dietary knowledge, attitudes, and behaviors to identify the educational needs of entering medical students. On average, dietary behavior and background knowledge of the diet-coronary heart disease association compared favorably to national dietary recommendations and knowledge of the U.S. public. However, practical knowledge necessary for diet counseling was weak, and attitudes about the "prudent" diet were poor. More favorable attitude scores were associated with healthier eating habits, while greater knowledge was not. Our results suggest that entering medical students already have a basic understanding of the diet-heart disease link, which is covered in the curricula of most medical schools. Medical education should include more emphasis on practical dietary knowledge and improving attitudes about the prudent diet.