Effects of Maternal HIV Infection on Early Kaposi Sarcoma-Associated Herpesvirus Seroconversion in a Kenyan Mother-Infant Cohort

BACKGROUND

We identified whether maternal human immunodeficiency virus (HIV) infection during pregnancy affects transplacental transfer of Kaposi sarcoma-associated herpesvirus (KSHV)-specific antibodies and subsequent infant infection.

METHODS

We followed pregnant Kenyan women through delivery and their infants until age 2 years. Children were classified as HIV-exposed uninfected (HEU) or HIV-unexposed uninfected (HUU) based on maternal HIV status. Maternal venous and cord blood at delivery and child venous blood every 6 months were tested for antibodies to 20 KSHV antigens by multiplex bead-based immunoassay. Multiple comparisons were adjusted using false discovery rate (FDR).

RESULTS

Maternal HIV infection was significantly associated with decreased transplacental transfer of antibodies against all KSHV antigens and lower cord blood levels for 8 antigens at FDR P < .10. Neither birth to 6-month antibody level changes nor 6-month levels differed in HEU and HUU, except for ORF50. By age 24 months, 74% of children KSHV seroconverted but HEU and HUU did not differ in time to seroconversion nor 2-year seropositivity after adjustment for child malaria infection.

CONCLUSIONS

Maternal HIV infection reduced a child's initial KSHV antibody levels but did not affect age of infection. Regardless of HIV exposure in utero, KSHV seroconversion in Kenyan children occurred early; associated factors must be identified.

Provider Perceptions of Oxygenation Strategies for Critically Ill Trauma Patients With and Without Moderate-to-Severe Traumatic Brain Injury

BACKGROUND

Hypoxia and hyperoxia (pulse oximetry [SpO2] > 96%) are associated with increased mortality in critically ill patients. However, provider practices regarding oxygenation in traumatic brain injury (TBI) patients are unknown. This study assesses views on oxygenation of critically ill trauma patients with and without TBI and how this varies between Neurological ICU (NeuroICU) and Surgical-Trauma ICU (STICU) providers.

METHODS

This is a cross-sectional survey of Level I trauma center's NeuroICU and STICU providers. We used Likert scales, yes-no questions, and multiple-choice case-based scenarios to characterize provider views on oxygenation with descriptive statistics to characterize responses. Significant differences regarding TBI and non-TBI patients or NeuroICU and STICU providers were determined using Fisher's exact test and a P-value of .05.

RESULTS

A total of 83 providers initiated the survey, and 53 providers completed it. Most providers identified a threshold SpO2 < 92% for the administration of supplemental oxygen in critically ill TBI patients. A total of 9% of providers "somewhat or completely agreed" that they were more likely to give supplemental oxygen to a critically ill trauma patient with TBI than one without TBI and the same SpO2. A total of 48% of providers selected an SpO2 < 90% as the point at which supplemental oxygen should be initiated in patients without TBI, compared to 27% of providers in patients with TBI (P < .01). This threshold for supplemental oxygen use varied by provider type for non-TBI patients, but not for TBI patients (30% NeuroICU and 69% STICU providers selected SpO2 < 90% in non-TBI, P < .05; 30% NeuroICU and 35% STICU providers selected SpO2 < 90% in TBI, P = .85).

CONCLUSIONS

Critical care providers at UCHealth University of Colorado Hospital approach the oxygenation of critically ill trauma patients with and without TBI differently. Specifically, critical care respondents accepted a different lower oxygen saturation threshold for TBI and non-TBI patients. NeuroICU and STICU respondents differed in their threshold for the down-titration of supplemental oxygen. Targeted education for critical care providers may reduce these discrepancies and optimize oxygen use.

Multimodal Biomarkers That Predict the Presence of Gleason Pattern 4: Potential Impact for Active Surveillance

PURPOSE

Latent grade group ≥2 prostate cancer can impact the performance of active surveillance protocols. To date, molecular biomarkers for active surveillance have relied solely on RNA or protein. We trained and independently validated multimodal (mRNA abundance, DNA methylation, and/or DNA copy number) biomarkers that more accurately separate grade group 1 from grade group ≥2 cancers.

MATERIALS AND METHODS

Low- and intermediate-risk prostate cancer patients were assigned to training (n=333) and validation (n=202) cohorts. We profiled the abundance of 342 mRNAs, 100 DNA copy number alteration loci, and 14 hypermethylation sites at 2 locations per tumor. Using the training cohort with cross-validation, we evaluated methods for training classifiers of pathological grade group ≥2 in centrally reviewed radical prostatectomies. We trained 2 distinct classifiers, PRONTO-e and PRONTO-m, and validated them in an independent radical prostatectomy cohort.

RESULTS

PRONTO-e comprises 353 mRNA and copy number alteration features. PRONTO-m includes 94 clinical, mRNAs, copy number alterations, and methylation features at 14 and 12 loci, respectively. In independent validation, PRONTO-e and PRONTO-m predicted grade group ≥2 with respective true-positive rates of 0.81 and 0.76, and false-positive rates of 0.43 and 0.26. Both classifiers were resistant to sampling error and identified more upgrading cases than a well-validated presurgical risk calculator, CAPRA (Cancer of the Prostate Risk Assessment; P < .001).

CONCLUSIONS

Two grade group classifiers with superior accuracy were developed by incorporating RNA and DNA features and validated in an independent cohort. Upon further validation in biopsy samples, classifiers with these performance characteristics could refine selection of men for active surveillance, extending their treatment-free survival and intervals between surveillance.

Evidence for Aerosol Transfer of SARS-CoV-2-Specific Humoral Immunity

Infectious particles can be shared through aerosols and droplets formed as the result of normal respiration. Whether Abs within the nasal/oral fluids can similarly be shared between hosts has not been investigated. The circumstances of the SARS-CoV-2 pandemic facilitated a unique opportunity to fully examine this provocative idea. The data we show from human nasal swabs provides evidence for the aerosol transfer of Abs between immune and nonimmune hosts.

Repeat Ivermectin Mass Drug Administrations for Malaria Control II: Protocol for a Double-blind, Cluster-Randomized, Placebo-Controlled Trial for the Integrated Control of Malaria

BACKGROUND

The gains made against malaria have stagnated since 2015, threatened further by increasing resistance to insecticides and antimalarials. Improvement in malaria control necessitates a multipronged strategy, which includes the development of novel tools. One such tool is mass drug administration (MDA) with endectocides, primarily ivermectin, which has shown promise in reducing malaria transmission through lethal and sublethal impacts on the mosquito vector.

OBJECTIVE

The primary objective of the study is to assess the impact of repeated ivermectin MDA on malaria incidence in children aged ≤10 years.

METHODS

Repeat Ivermectin MDA for Malaria Control II is a double-blind, placebo-controlled, cluster-randomized, and parallel-group trial conducted in a setting with intense seasonal malaria transmission in Southwest Burkina Faso. The study included 14 discrete villages: 7 (50%) randomized to receive standard measures (seasonal malaria chemoprevention [SMC] and bed net use for children aged 3 to 59 months) and placebo, and 7 (50%) randomized to receive standard measures and monthly ivermectin MDA at 300 μg/kg for 3 consecutive days, provided under supervision to all eligible village inhabitants, over 2 successive rainy seasons. Nonpregnant individuals >90 cm in height were eligible for ivermectin MDA, and cotreatment with ivermectin and SMC was not permitted. The primary outcome is malaria incidence in children aged ≤10 years, as assessed by active case surveillance. The secondary safety outcome of repeated ivermectin MDA was assessed through active and passive adverse event monitoring.

RESULTS

The trial intervention was conducted from July to November in 2019 and 2020, with additional sampling of humans and mosquitoes occurring through February 2022 to assess postintervention changes in transmission patterns. Additional human and entomological assessments were performed over the 2 years in a subset of households from 6 cross-sectional villages. A subset of individuals underwent additional sampling in 2020 to characterize ivermectin pharmacokinetics and pharmacodynamics. Analysis and unblinding will commence once the database has been completed, cleaned, and locked.

CONCLUSIONS

Our trial represents the first study to directly assess the impact of a novel approach for malaria control, ivermectin MDA as a mosquitocidal agent, layered into existing standard-of-care interventions. The study was designed to leverage the current SMC deployment infrastructure and will provide evidence regarding the additional benefit of ivermectin MDA in reducing malaria incidence in children.

TRIAL REGISTRATIONS

ClinicalTrials.gov NCT03967054; https://clinicaltrials.gov/ct2/show/NCT03967054 and Pan African Clinical Trials Registry PACT201907479787308; https://pactr.samrc.ac.za/TrialDisplay.aspx?TrialID=8219.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/41197.

Hyperoxia is associated with a greater risk for mortality in critically ill traumatic brain injury patients than in critically ill trauma patients without brain injury

OBJECTIVE

The role of hyperoxia in patients with traumatic brain injury (TBI) remains controversial. The objective of this study was to determine the association between hyperoxia and mortality in critically ill TBI patients compared to critically ill trauma patients without TBI.

DESIGN

Secondary analysis of a multicenter retrospective cohort study.

SETTING

Three regional trauma centers in Colorado, USA, between October 1, 2015, and June 30, 2018.

PATIENTS

We included 3464 critically injured adults who were admitted to an intensive care unit (ICU) within 24 h of arrival and qualified for inclusion into the state trauma registry. We analyzed all available SpO2 values during the first seven ICU days. The primary outcome was in-hospital mortality. Secondary outcomes included the proportion of time spent in hyperoxia (defined as SpO2 > 96%) and ventilator-free days.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

In-hospital mortality occurred in 163 patients (10.7%) in the TBI group and 101 patients (5.2%) in the non-TBI group. After adjusting for ICU length of stay, TBI patients spent a significantly greater amount of time in hyperoxia versus non-TBI patients (p = 0.024). TBI status significantly modified the effect of hyperoxia on mortality. At each specific SpO2 level, the risk of mortality increases with increasing FiO2 for both patients with and without TBI. This trend was more pronounced at lower FiO2 and higher SpO2 values, where a greater number of patient observations were obtained. Among patients who required invasive mechanical ventilation, TBI patients required significantly more days of ventilation to day 28 than non-TBI patients.

CONCLUSIONS

Critically ill trauma patients with a TBI spend a greater proportion of time in hyperoxia compared to those without a TBI. TBI status significantly modified the effect of hyperoxia on mortality. Prospective clinical trials are needed to better assess a possible causal relationship.

ED-based COVID-19 vaccination campaign finds higher vaccination rates for individuals from racial and ethnic minority groups compared with clinic setting

BACKGROUND

Emergency department visits associated with Coronavirus Disease 2019 (COVID-19) continue to indicate racial and ethnic inequities. We describe the sociodemographic characteristics of individuals receiving COVID-19 vaccination in the emergency department and compare with an outpatient clinic population and emergency department (ED) patients who were eligible but not vaccinated.

METHODS

We conducted a retrospective analysis of electronic health record data at an urban academic ED from May to July 2021. The primary aim was to characterize the ED-vaccinated population, compared with ED patients who were eligible but unvaccinated and the physically adjacent outpatient vaccination clinic population.

RESULTS

A total of 627 COVID-19 vaccinations were administered in the ED. Overall, 49% of ED patients during that time had already received at least one vaccine dose prior to ED arrival. Hispanic, non-Hispanic Black patients, and patients on non-commercial insurance had higher odds of being vaccinated in the ED as compared with outpatient clinic setting. Among eligible ED patients, men and patients who were uninsured/self-pay were more likely to accept ED vaccination.

CONCLUSIONS

This ED COVID-19 vaccination campaign demonstrated a higher likelihood to vaccinate individuals from racial/ethnic minority groups, those with high social vulnerability, and non-commercial insurance, when compared with a co-located outpatient vaccination clinic.

A multicenter cluster randomized, stepped wedge implementation trial for targeted normoxia in critically ill trauma patients: study protocol and statistical analysis plan for the Strategy to Avoid Excessive Oxygen (SAVE-O2) trial

Background

Targeted normoxia (SpO₂ 90–96% or PaO₂ 60–100 mmHg) may help to conserve oxygen and improve outcomes in critically ill patients by avoiding potentially harmful hyperoxia. However, the role of normoxia for critically ill trauma patients remains uncertain. The objective of this study is to describe the study protocol and statistical analysis plan for the Strategy to Avoid Excessive Oxygen for Critically Ill Trauma Patients (SAVE-O2) clinical trial.

Methods

Design, setting, and participants: Protocol for a multicenter cluster randomized, stepped wedge implementation trial evaluating the effectiveness of a multimodal intervention to target normoxia in critically ill trauma patients at eight level 1 trauma centers in the USA. Each hospital will contribute pre-implementation (control) and post-implementation (intervention) data. All sites will begin in the control phase with usual care. When sites reach their randomly assigned time to transition, there will be a one-month training period, which does not contribute to data collection. Following the 1-month training period, the site will remain in the intervention phase for the duration of the trial.

Main outcome measures: The primary outcome will be supplemental oxygen-free days, defined as the number of days alive and not on supplemental oxygen. Secondary outcomes include in-hospital mortality to day 90, hospital-free days to day 90, ventilator-free days (VFD) to day 28, time to room air, Glasgow Outcome Score (GOS), and duration of time receiving supplemental oxygen.

Discussion

SAVE-O2 will determine if a multimodal intervention to improve compliance with targeted normoxia will safely reduce the need for concentrated oxygen for critically injured trauma patients. These data will inform military stakeholders regarding oxygen requirements for critically injured warfighters, while reducing logistical burden in prolonged combat casualty care.

Trial registration

ClinicalTrials.govNCT04534959. Registered September 1, 2020.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05688-6.

A quasiexperimental study of targeted normoxia in critically ill trauma patients

BACKGROUND

Avoidance of hypoxia and hyperoxia may reduce morbidity and mortality in critically ill civilian and military trauma patients. The objective of this study was to determine if a multimodal quality improvement intervention increases adherence to a consensus-based, targeted normoxia strategy. We hypothesized that this intervention would safely improve compliance with targeted normoxia.

METHODS

This is a pre/postquasiexperimental pilot study to improve adherence to normoxia, defined as a pulse oximetry (SpO2) of 90% to 96% or an arterial partial pressure oxygen (PaO2) of 60 to 100 mm Hg. We used a multimodal informatics and educational intervention guiding clinicians to safely titrate supplemental oxygen to normoxia based on SpO2 monitoring in critically ill trauma patients admitted to the surgical-trauma or neurosurgical intensive care unit within 24 hours of emergency department arrival. The primary outcome was effectiveness in delivering targeted normoxia (i.e., an increase in the probability of being in the targeted normoxia range and/or a reduction in the probability of being on a higher fraction-inspired oxygen concentration [FiO2]).

RESULTS

Analysis included 371 preintervention subjects and 201 postintervention subjects. Preintervention and postintervention subjects were of similar age, race/ethnicity, and sex and had similar comorbidities and Acute Physiologic and Chronic Health Evaluation II scores. Overall, the adjusted probability of being hyperoxic while on supplemental oxygen was reduced during the postintervention period (adjusted odds ratio, 0.74; 95% confidence interval, 0.57-0.97). There was a higher probability of being on room air (FiO2, 0.21) in the postintervention period (adjusted odds ratio, 1.38; 95% confidence interval, 0.83-2.30). In addition, there was a decreased amount of patient time spent on higher levels of FiO2 (FiO2, >40%) without a concomitant increase in hypoxia.

CONCLUSION

A multimodal intervention targeting normoxia in critically ill trauma patients increased normoxia and lowered the use of supplemental oxygen. A large clinical trial is needed to validate the impact of this protocol on patient-centered clinical outcomes.

LEVEL OF EVIDENCE

Therapeutic/care management, level II.

Design and analysis of a 2-year parallel follow-up of repeated ivermectin mass drug administrations for control of malaria: Small sample considerations for cluster-randomized trials with count data

BACKGROUND

Cluster-randomized trials allow for the evaluation of a community-level or group-/cluster-level intervention. For studies that require a cluster-randomized trial design to evaluate cluster-level interventions aimed at controlling vector-borne diseases, it may be difficult to assess a large number of clusters while performing the additional work needed to monitor participants, vectors, and environmental factors associated with the disease. One such example of a cluster-randomized trial with few clusters was the "efficacy and risk of harms of repeated ivermectin mass drug administrations for control of malaria" trial. Although previous work has provided recommendations for analyzing trials like repeated ivermectin mass drug administrations for control of malaria, additional evaluation of the multiple approaches for analysis is needed for study designs with count outcomes.

METHODS

Using a simulation study, we applied three analysis frameworks to three cluster-randomized trial designs (single-year, 2-year parallel, and 2-year crossover) in the context of a 2-year parallel follow-up of repeated ivermectin mass drug administrations for control of malaria. Mixed-effects models, generalized estimating equations, and cluster-level analyses were evaluated. Additional 2-year parallel designs with different numbers of clusters and different cluster correlations were also explored.

RESULTS

Mixed-effects models with a small sample correction and unweighted cluster-level summaries yielded both high power and control of the Type I error rate. Generalized estimating equation approaches that utilized small sample corrections controlled the Type I error rate but did not confer greater power when compared to a mixed model approach with small sample correction. The crossover design generally yielded higher power relative to the parallel equivalent. Differences in power between analysis methods became less pronounced as the number of clusters increased. The strength of within-cluster correlation impacted the relative differences in power.

CONCLUSION

Regardless of study design, cluster-level analyses as well as individual-level analyses like mixed-effects models or generalized estimating equations with small sample size corrections can both provide reliable results in small cluster settings. For 2-year parallel follow-up of repeated ivermectin mass drug administrations for control of malaria, we recommend a mixed-effects model with a pseudo-likelihood approximation method and Kenward-Roger correction. Similarly designed studies with small sample sizes and count outcomes should consider adjustments for small sample sizes when using a mixed-effects model or generalized estimating equation for analysis. Although the 2-year parallel follow-up of repeated ivermectin mass drug administrations for control of malaria is already underway as a parallel trial, applying the simulation parameters to a crossover design yielded improved power, suggesting that crossover designs may be valuable in settings where the number of available clusters is limited. Finally, the sensitivity of the analysis approach to the strength of within-cluster correlation should be carefully considered when selecting the primary analysis for a cluster-randomized trial.

A prospective study of type 2 diabetes, metformin use, and risk of breast cancer

BACKGROUND

Type 2 diabetes (T2D) has been associated with increased breast cancer risk, but commonly prescribed antidiabetic medications such as metformin may reduce risk. Few studies have investigated T2D and medications together in relation to breast cancer.

PATIENTS AND METHODS

Data came from 44 541 Sister Study participants aged 35 to 74 years at enrollment (2003-2009) who satisfied eligibility criteria, followed through 15 September 2017. Information on time-varying, self-reported, physician-diagnosed, prevalent and incident T2D, use of antidiabetic medications, and covariates was obtained from baseline and follow-up questionnaires. Incident breast cancers were confirmed with medical records. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated.

RESULTS

During follow-up (median, 8.6 years), 2678 breast cancers were diagnosed at least 1 year after enrollment. There were 3227 women (7.2%) with prevalent and 2389 (5.3%) with incident T2D, among whom 61% (n = 3386) were ever treated with metformin. There was no overall association between T2D and breast cancer risk (HR 0.99; 95% CI, 0.87-1.13). However, T2D was associated with increased risk of triple-negative breast cancer (HR 1.40; 95% CI, 0.90-2.16). Compared with not having T2D, T2D with metformin use was not associated with overall breast cancer risk (HR 0.98; 95% CI, 0.83-1.15), but it was associated with decreased risk of estrogen receptor (ER)-positive breast cancer (HR 0.86; 95% CI 0.70-1.05) and increased risk of ER-negative (HR 1.25; 95% CI, 0.84-1.88) and triple-negative breast cancer (HR 1.74; 95% CI, 1.06-2.83). The inverse association with ER-positive cancer was stronger for longer duration (≥10 year) metformin use (HR 0.62; 95% CI, 0.38-1.01; P for trend = 0.09). Results were supported by sensitivity analyses.

CONCLUSION

Our findings suggest that associations between T2D and breast cancer may differ by hormone receptor status and that associations between T2D and ER-positive breast cancer may be reduced by long-term metformin use.

Malaria during pregnancy and transplacental transfer of Kaposi sarcoma-associated herpesvirus (KSHV) antibodies: a cohort study of Kenyan mother and child pairs

BACKGROUND

Kaposi sarcoma-associated herpesvirus (KSHV) seroprevalence in sub-Saharan African children can range up to 50% by age 2 years but factors affecting early age of KSHV infection are not well understood. Malaria during pregnancy has been associated with hindered transplacental transfer of antibodies to several pathogens but whether it affects transplacental transfer of KSHV antibodies is unknown. We aimed to determine if in utero malaria exposure reduced the transfer of KSHV antibodies across the placenta.

METHODS

A cohort study in Kisumu, Kenya enrolled pregnant women at their first antenatal clinic (ANC) visit and followed them through delivery. We included 70 KSHV-positive, HIV-negative mothers and their children. KSHV antibody levels were measured by ELISA (K8.1, ORF73) and multiplex assay (K8.1, ORF73, K10.5, ORF38, ORF50). Transplacental transfer of antibodies was measured by the cord to maternal blood ratio (CMR) of KSHV antibodies. Malaria during pregnancy was defined as detection of Plasmodium falciparum (Pf) DNA at any ANC visit or delivery. Among women with malaria during pregnancy, we examined time of last malaria infection prior to delivery (< 27 vs. 27+ weeks gestation) and malaria incidence rate (MIR) (episodes/100 person-weeks).

RESULTS

KSHV seroprevalence (positive for K8.1 or ORF73 by ELISA) among pregnant women was 88%. Neither malaria during pregnancy, malaria infection timing, nor MIR were associated with maternal delivery KSHV antibody blood levels. Maternal delivery and cord blood KSHV antibody levels were highly correlated but these correlations did not differ by malaria during pregnancy. KSHV transplacental antibody transfer was not associated with malaria during pregnancy, malaria infection timing, nor MIR.

CONCLUSIONS

Malaria during pregnancy does not appear to affect transfer of KSHV antibodies across the placenta.

0366 Sleep Health Dimensions, Disturbances, and Disruptors Among White, Black, Hispanic/ Latina, and Asian Women

Introduction

Despite the importance of sleep for health promotion and disease prevention, data are limited regarding the distribution of multiple sleep health dimensions, disturbances, and disruptors among women, especially racial/ethnic minorities who disproportionately experience poor sleep.

Methods

To determine the prevalence of sleep health, disturbances, and disruptors (e.g., short sleep duration, sleep debt, insomnia symptoms, light exposure at night) overall and among Black, Hispanic/Latina, and Asian compared to White women, we used cross-sectional data collected by the Sister Study at enrollment (2003-2009) and two follow-ups (2012-2014, 2014-2016). Adjusting for sociodemographics, health behaviors, and health conditions including depression, we used Poisson regression with robust variance to estimate prevalence ratios (PRs) for unfavorable sleep among racial/ethnic minority compared to White women.

Results

Of the 49,874 eligible women (mean age ± standard deviation: 55.7 ± 9.0 years, 84.8% ≥high school education, 74.7% married) 85.3% were White, 9.0% Black, 5.1% Hispanic/Latina, and 0.7% Asian. Overall, 70% reported the recommended amount of sleep, 15.7% inconsistent weekly sleep patterns, 26% sleep debt, and 14% insomnia symptoms plus short sleep. Racial/ethnic minorities were much more likely than whites to report very short (≤5 hours) sleep (PRBlack)=5.98[95% Confidence Interval: 4.67-7.66]; PRLatina=2.83[1.98-4.04]; PRAsian=5.41[2.41-12.13] and to report needing &lt;7 hours to feel their best (PRBlack=2.95[2.75-3.17]; PRLatina=1.85[1.65-2.07]; PRAsian=2.66[2.10-3.37]). Black and Hispanic/Latina women had a higher prevalence than whites of insomnia, short sleep plus insomnia, inconsistent sleep, sleep debt, and frequent napping; however, all racial/ethnic minorities were less likely to report daytime sleepiness (PRBlack=0.82[0.78-0.85]; PRLatina=0.94[0.89-0.98]; PRAsian=0.79[0.69-0.92]) and restless leg syndrome. Witnessed sleep apnea was higher among Black women, and REM sleep disorder did not differ across racial/ethnic groups. Sleeping with room lights or a television on was more prevalent among racial/ethnic minorities (PRBlack=1.78[1.71-1.86]; PRLatina=1.27[1.17-1.37]; PRAsian=1.62[1.32-1.99]).

Conclusion

Poor sleep health, disturbances, and disruptors were prevalent among women and varied across racial/ethnic groups in ways that may contribute to health disparities.

Support

This work was funded by the Intramural Program at the National Institutes of Health, National Institute of Environmental Health Sciences (Z1A ES103325-01 to (CLJ) and Z01 ES044005 to (DPS)).

1016 Multiple Sleep Disturbances and Hypertension Risk Among White, Black, and Hispanic/Latina Women

Introduction

Poor sleep has been associated with a higher risk of hypertension, but few prospective studies have included multiple sleep dimensions and few have investigated age differences or racial/ethnic disparities in this relationship among pre- and post-menopausal women.

Methods

To investigate the association between sleep disturbances and hypertension risk, we used data from women in the United States enrolled in the Sister Study who were aged 35 to 74 years at baseline (2003 to 2009) and did not have hypertension at enrollment. Participants were followed through September 2017. Sleep duration, inconsistent weekly sleep patterns, sleep debt, frequent napping, and insomnia symptoms were reported at baseline. During follow-up, participants reported whether they were diagnosed by a healthcare provider with hypertension. Adjusting for sociodemographic characteristics, health behaviors, and health conditions including diabetes and depression, we used Cox Proportional Hazards regression to estimate hypertension risk among women with vs. without unfavorable sleep characteristics. We also investigated potential modification by race/ethnicity, age,and menopausal status.

Results

Of 33,175 women without hypertension at baseline (mean age ± standard deviation: 53.9 ±8.8 years; 88.8% White, 6.4% Black, and 4.9% Hispanic/Latina), 19.9% developed hypertension over a median follow-up of 9.2 years (interquartile range: 7.6 to 10.9). After adjustment, insomnia symptoms (hazard ratio[HR]=1.08 (95% Confidence Interval [CI]: 1.03-1.15)) and insomnia symptoms combined with short sleep (HR=1.14 (95% CI: 1.06-1.23)) were associated with incident hypertension. While similar across race/ethnicity, these associations were stronger in younger (age &lt;54 vs. ≥54 years) and premenopausal vs. postmenopausal women (p-values for interaction &lt;0.05).

Conclusion

Sleep disturbances related to insomnia were associated with an increased risk of hypertension, especially among younger and premenopausal women.

Support

This work was funded by the Intramural Program at the National Institutes of Health (NIH), National Institute of Environmental Health Sciences (NIEHS, Z1AES103325-01 [CLJ] and Z01 ES044005 [DPS]).

0361 Birthplace Moderates Racial/Ethnic Disparities in Multiple Sleep Characteristics Among Non-Hispanic Whites and Hispanic/Latino Heritage Groups in the United States

Introduction

Sleep duration disparities by Hispanic/Latino heritage exist; however, few studies have additionally investigated sleep quality disparities by heritage and birthplace, nor have studies compared foreign-born to US-born Non-Hispanic Whites (NHWs).

Methods

Using pooled 2004-2017 National Health Interview Survey data, we investigated whether sleep disparities varied by birthplace among adult NHWs and Hispanic/Latino heritage groups. Adjusting for sociodemographic and behavioral/clinical characteristics, survey-weighted Poisson regressions with robust variance estimated prevalence ratios (PRs) and 95% confidence intervals (CIs) of self-reported sleep characteristics. Sleep characteristics were compared among foreign-born NHWs and Hispanic/Latino heritage groups vs. US-born NHWs. Sleep characteristics were also compared across Hispanic/Latino heritage groups vs. foreign-born NHWs.

Results

Among 254,699 participants (Meanage±SE: 47±0.9 years; 49% female), 81% self-identified as NHW (n=207,154), 12% Mexican (n=30,100), 2% Puerto Rican n=5,077), 1% Cuban(n=2,518), 1% Dominican (n=1,658), and 3% Central/South American (n=8,162). Compared to US-born NHWs, foreign-born NHWs were more likely to report &gt;9-hours sleep duration (PR=1.11[95% CI: 1.01-1.21]) and poor sleep quality (e.g., PRtrouble staying asleep=1.27[1.17-1.37]), and US-born Mexicans were no more likely to report shorter sleep duration while foreign-born Mexicans were less likely (PR&lt;6-hours=0.52[0.47-0.57], PR6-&lt;7-hours=0.72[0.68-0.76]). Although US-born and foreign-born Mexicans had lower prevalence of poor sleep quality compared to US-born NHWs, PRs were lowest for foreign-born Mexicans. Compared to foreign-born NHWs, US-born Mexicans were more likely to report shorter sleep duration, but foreign-born Mexicans were no more likely. Regardless of birthplace, Puerto Ricans were more likely (e.g., PR&lt;6-hours=1.37[1.24-1.60]) and Cubans were less likely (e.g., PR&lt;6-hours=0.81[0.68-0.96]) to report shorter sleep duration vs. US-born NHWs. Compared to US-born NHWs, Dominicans reported better sleep duration and quality. Sleep duration and quality did not differ among Dominicans vs. foreign-born NHWs.

Conclusion

Sleep disparities varied by birthplace and Hispanic/Latino heritage. Birthplace of both NHWs and racial/ethnic minority groups should be considered in disparities research.

Support

This work was funded by the Intramural Program at the National Institutes of Health (NIH), National Institute of Environmental Health Sciences (NIEHS, Z1AES103325-01) and the Division of Intramural Research, National Institute on Minority Health and Health Disparities.

0367 Social Determinants of Black-White Disparities in the Work-Sleep Relationship by Occupational Class: A Sequential Mixed Methods Approach

Introduction

Although Black adults disproportionately work in lower-wage, lower-skilled jobs and experience short sleep (&lt;7 hours), which has been shown to vary by employment industry and occupation, there is scant literature regarding the influence of the work-sleep relationship on racial/ethnic sleep disparities. Our prior quantitative research based on nationally-representative data revealed a novel finding that the prevalence of short sleep was generally highest at professional occupational classes among Black adults but was the least prevalent among their White counterparts.

Methods

To identify reasons for short sleep generally increasing with increasing professional occupations among blacks but decreasing among whites, we conducted a qualitative study using a sequential mixed methods design among Black and White workers across a range of industries and occupations. Occupations were classified as “professional” (e.g., doctors; lawyers) or “non-professional” (e.g., retail; food service). Race-matched trained facilitators conducted 36 focus groups that were homogenous in terms of race-sex/gender-occupational class and 63 one-on-one interviews (N=334 overall participants) using semi-structured interview guides. NVivo software was used to identify themes/patterns.

Results

Participants were a mean age of 41 ± 11 years, 42% were men, 58% had an annual income of ≥$50,000, and 57% were professionals. Black professionals overwhelmingly described less informational and emotional support as well as needing to “work twice as hard to get half as far” (i.e., John Henryism) compared to coworkers as potential explanations for work-sleep disparities. Both Black and White professionals identified longstanding social structures, interpersonal discrimination, income disparities, and familial or self-imposed pressures to succeed. White professional women frequently reported experiences with gender discrimination, which - they reported - may intersect with and amplify the effects of racial discrimination among Black women. Regardless of occupational class, Black men additionally described unique stressors (e.g., political climate; finances; police). White men frequently avoided discussing disparities, and the existence of disparities was often denied/questioned by non-professionals across race and sex/gender.

Conclusion

Our findings inform future research and interventions designed to illuminate and/or address sleep disparities emanating from the workplace.

Support

This work was funded by the Intramural Program at the National Institute of Environmental Health Sciences (Z1AES103325-01).

Adolescent Use of Hair Dyes, Chemical Straighteners and Perms in Relation to Breast Cancer Risk in the Sister Study

Hair products may contain hormonally active and carcinogenic compounds. We evaluated the risk of breast cancer associated with adolescent use of hair dyes, chemical straighteners and perms in a large prospective U.S. cohort. Methods: Sister Study participants (n = 47,833) were ages 35–74 years and had a sister who had been diagnosed with breast cancer at the time of enrollment (2003–2009). Enrollment questionnaires obtained information on demographics and lifestyle factors as well as frequency of use of hair dyes, chemical straighteners, and perms at ages 10–13 years. Cox proportional hazards models were used to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (95% CIs) for the association between adolescent hair product use and breast cancer risk (invasive cancer and ductal carcinoma in situ). We considered whether associations varied by invasiveness, estrogen receptor (ER) status of the tumor, menopause status and race. Results: Over an average of 8.3 years of follow-up, 2,829 cases were diagnosed. Hair dye use at ages 10–13 years was uncommon and not associated with breast cancer risk (e.g. permanent hair dye, &lt;3%; HR = 0.96, 95% CI: 0.76–1.22). Use of perms (34% non-Hispanic white vs. 8% black women) and straighteners (10% non-Hispanic white vs 75% black women) at ages 10–13 years varied by race. An elevated HR for breast cancer was observed for frequent use of chemical straighteners (HR = 1.27, 95% CI: 0.98–1.65). Though based on small numbers, this association was most pronounced for ER- invasive (HR = 2.04, 95% CI: 0.98–4.24) and premenopausal breast cancer (HR = 2.18, 95% CI 1.27–3.74). Frequent use of perms was also associated with a higher risk of invasive breast cancer and ER- tumors (HR = 1.25, 95% CI: 1.00–1.57 and HR = 1.69, 95%CI: 0.96–2.98, respectively). Although product use varied by race, associations with breast cancer did not. Conclusions: Frequent use of chemical straighteners or perms during the ages of 10–13 years was associated with a higher risk of breast cancer. These results suggest that exposure to the chemicals in these hair products, especially during adolescence which may be an important biological window of susceptibility, may play a role in breast carcinogenesis.

Differences in the Epstein-Barr Virus gp350 IgA Antibody Response Are Associated With Increased Risk for Coinfection With a Second Strain of Epstein-Barr Virus

BACKGROUND

The Epstein-Barr virus (EBV) viral glycoprotein gp350 has been proposed as a candidate antigen for an EBV vaccine. However, the proposed formulations of these vaccines have not taken into account the presence of 2 unique EBV strains (EBV-1 and EBV-2) present in areas of high incidence of the EBV-associated cancer, Burkitt lymphoma.

METHODS

In this study, we analyze the kinetics of EBV-1 and EBV-2 infection in an asymptomatic infant cohort from Kisumu, Kenya. We also analyzed the kinetics of the antibody response against 5 EBV antigens, gp350 (IgG and IgA), VCA (IgG), EBNA-1 (IgG), EAd (IgG), and Zta (IgG).

RESULTS

We observed a high frequency of coinfection with both EBV types over time, with the only observable defect in the antibody response in infants coinfected being a significantly lower level of anti-gp350 IgA at peak response. Gp350 IgA levels were also significantly lower in coinfected infants 2.5 months postinfection and at the time of coinfection.

CONCLUSIONS

These results suggest that anti-gp350 IgA antibodies may be important for sterilizing immunity against secondary infection. These findings have implications for the development of an efficacious EBV vaccine to prevent both EBV-1 and EBV-2 infection in a population at high risk for Burkitt lymphoma.

Impact of an integrated model of care on potentially preventable hospitalizations for people with Type 2 diabetes mellitus

AIMS

To evaluate the impact of an integrated model of care for patients with complex Type 2 diabetes mellitus on potentially preventable hospitalizations.

METHODS

A prospective controlled trial was conducted comparing a multidisciplinary, community-based, integrated primary-secondary care diabetes service with usual care at a hospital diabetes outpatient clinic. Study and hospital admissions data were linked for the period from 12 months before to 24 months after commencement of the trial. The primary outcome was the number of potentially preventable hospitalizations with diabetes-related principal diagnoses. Length of stay once hospitalized was also reported.

RESULTS

Of 327 adult participants, 206 were hospitalized and accounted for 667 admissions during the study period. Compared with the usual care group, patients in the integrated model of care group were nearly half as likely to be hospitalized for a potentially preventable diabetes-related principal diagnosis in the 24 months after study commencement (incidence rate ratio 0.53, 95% CI 0.29, 0.96; P = 0.04). The magnitude of the result remained similar after adjusting for age, sex, education and baseline HbA1c concentration (incidence rate ratio 0.54, 95% CI 0.29, 1.01; P = 0.05).When hospitalized, patients in the integrated care group had a similar length of stay compared with those in the usual care group (median difference -2 days, 95% CI -6.5, 2.3; P = 0.33).

CONCLUSIONS

Patients receiving the integrated model of care had a reduction in the number of hospitalizations when the principal diagnosis for admission was a diabetes-related complication. Integrated models of care for people with complex diabetes can reduce hospitalizations and help attempts to curtail increasing demand on finite health services.

Model of care for the management of complex Type 2 diabetes managed in the community by primary care physicians with specialist support: an open controlled trial

AIMS

To evaluate patient outcomes for a novel integrated primary/specialist model of community care for complex Type 2 diabetes mellitus management compared with outcomes for usual care at a tertiary hospital for diabetes outpatients.

METHODS

This was a prospective open controlled trial performed in a primary and tertiary care setting in Australia. A total of 330 patients with Type 2 diabetes aged >18 years were allocated to an intervention (n=185) or usual care group (n=145). The intervention arm was a community-based model of care led by a general practitioner with advanced skills and an endocrinologist partnership. Usual care was provided via the hospital diabetes outpatient department. The primary end point was HbA(1c) concentration at 12 months. Secondary end points included serum lipids and blood pressure.

RESULTS

The mean change in HbA1c concentration in the intervention group was -9 mmol/mol (-0.8%) at 12 months and in the usual care group it was -2 mmol/mol (-0.2%) (95% CI -5,1). The percentage of patients in the intervention group achieving the HbA(1c) target of ≤53 mmol/mol (7%) increased from 21 to 42% (P<0.001); for the usual care group there was a 1% increase to 39% of patients attaining this target (P=0.99). Patients in the intervention group experienced significant improvements in blood pressure and total cholesterol compared with those in the usual care group. The percentage of patients achieving clinical targets was greater in the intervention group for the combined target of HbA(1c) concentration, blood pressure and LDL cholesterol.

CONCLUSIONS

A community-based, integrated model of complex diabetes care, delivered by general practitioners with advanced skills, produced clinical and process benefits compared with a tertiary diabetes outpatient clinic.

Transforming growth factor beta signalling and matrix metalloproteinases in the mucosa overlying Crohn's disease strictures

BACKGROUND AND AIMS

In addition to its crucial role in dampening tissue-damaging immune responses in the gut, transforming growth factor beta (TGFbeta) is a potent profibrogenic agent inducing collagen synthesis and regulating the balance between matrix-degrading matrix metalloproteinases (MMPs) and their inhibitors (TIMPs). TGFbeta signalling was investigated by analysis of Smad proteins and MMPs/TIMPs in the mucosa overlying strictures in patients with Crohn's disease (CD).

METHODS

Specimens were collected from macroscopically normal mucosa overlying strictured and non-strictured gut of patients with fibrostenosing CD. Isolated myofibroblasts were cultured with anti-TGFbeta blocking antibody or TGF beta 1. TGFbeta transcripts were analysed by quantitative reverse transcription-PCR (RT-PCR). Smad proteins and MMPs were determined by immunoblotting. MMP-12 activity was measured by a real-time MMP-12 activity assay. An in vitro wound-healing scratch assay was used to assess myofibroblast migration.

RESULTS

TGFbeta transcripts, phosphorylated Smad2-Smad3 (pSmad2-3) and TIMP-1 proteins were higher in mucosa overlying strictures than in mucosa overlying non-strictured areas. In contrast, mucosa overlying strictured gut had lower expression of Smad7, MMP-12 and MMP-3. Myofibroblasts from mucosa overlying strictured gut showed higher TGFbeta transcripts, a greater pSmad2-3 response to TGFbeta, increased TIMP-1, lower Smad7, increased collagen production and reduced migration ability compared with myofibroblasts from mucosa overlying non-strictured gut. TGFbeta blockade increased myofibroblast MMP-12 production and migration, more obviously in myofibroblasts isolated from mucosa overlying non-strictured compared with strictured gut.

CONCLUSIONS

Changes in TGF-beta signalling and MMP production were identified in the mucosa overlying strictures in CD which may give a window into the process of fibrosis.

Construction of somatic cell hybrids

Somatic cell hybridization is the method of choice to separate a chromosome of interest from the full chromosome complement and obtain a permanent source of the chromosome. This unit begins with the choice of fusion techniques and selectable markers for hybrids containing a chromosome of interest. The first set of protocols outline the production of whole-cell hybrids by fusion of two cell lines: a monolayer (adherent) recipient and a donor that may be adherent or grown in suspension. The second set of protocols outline the production of micronuclei containing a limited number of chromosomes, and enucleation of the micronuclei to form microcells for fusion with recipient cells. Support protocols describe the preparation and use of cloning cylinders to isolate colonies in tissue culture, subcloning of whole-cell hybrid populations to isolate lines that have segregated additional chromosomes, purification of microcell preparations, and molecular and cytogenetic methods for characterizing.

Effects of growth hormone on leucine absorption, intestinal morphology, and ultrastructure of the goldish intestine

The mechanisms whereby exogenous growth hormone modulates intestinal structure and function in fish were investigated. Goldfish (Carassius auratus) were fed commercial flake diet sprayed with recombinant carp growth hormone (cGH) daily for 1 month. Control animals received food sprayed with the vehicle. After 1 month of daily feedings, body mass and length were determined, and animals were sacrificed to study intestinal characteristics. Sections of foregut were removed after determination of total gut length for measurement of leucine uptake, histology, and epithelial ultrastructure. Oral administration of cGH for 1 month resulted in a 40% increase in body mass and an 8% increase in body length above controls. Gut length was 43% greater and the gut length to body length ratio was 32% greater as a result of the cGH treatment. Feeding with cGH also resulted in a significant increase in leucine uptake and increased gut mucosal thickness. Analysis of transmission electron micrographs revealed significant increases in the microvillous height and density and epithelial surface area. The findings indicate that growth hormone added to feed may increase growth in fish, in part by significantly increasing gut length, mucosal thickness, and epithelial brush border surface area, leading to enhanced epithelial absorption.

Immune-dependent thrombocytopaenia in mice infected with Schistosoma mansoni

As has been shown previously, immunologically intact mice with patent Schistosoma mansoni infections had a significantly lower mean platelet number than intact uninfected mice (P<0.0001). However, platelet numbers in T-cell deprived mice with patent infections were not significantly different from those in uninfected T-cell deprived mice. Also, platelet counts in both the infected and uninfected T-cell deprived groups were not significantly different from those in intact uninfected mice. The S. mansoni-induced thrombocytopaenia in mice is thus seemingly immune dependent. Immunologically intact mice with chronic 12-week-old S. mansoni infections had IgG antibodies that were reactive in an ELISA-type assay with whole fixed platelets of both mouse and human origin. In Western immunoblots the IgG antibodies from chronically-infected mice reacted in particular against mouse and human platelet antigens of 90, 37 and 30 kDa. Antisera raised from 2 rabbits, immunized respectively with mouse and human platelet antigens, cross-reacted with antigens of the larval, adult worm and egg stages of S. mansoni. These results support the hypothesis that an anti-platelet antibody response may be the cause of the thrombocytopaenia observed in mice with patent schistosome infections.

Identification of a fibrinolytic enzyme in Schistosoma mansoni eggs and modulated blood fibrinogen metabolism in S. mansoni-infected mice

Aqueous extracts of Schistosoma mansoni eggs have been shown to have fibrinolytic activity inhibitable by a serine protease inhibitor. Fibrinolytic activity was not present in extracts of either adult worms or cercariae. A 27 kDa enzyme that was proteolytically active on fibrinogen in zymography and that degraded fibrinogen in a pattern similar to that of plasmin, is presumed to be responsible for the schistosome egg fibrinolytic activity. Anti-human fibrinogen antisera were shown to have antibodies that cross-reacted with mouse fibrinogen in Western immunoblots. Electroblotted sera from S. mansoni-infected and control uninfected mice displayed different antigenic profiles when probed with the cross-reactive anti-human fibrinogen antibodies, suggesting an alteration in mouse host fibrinogen metabolism as a result of the parasitic infection. We discuss the possibility that modulation of fibrinogen metabolism is a factor in a recently discovered anti-atherogenic effect exerted by schistosomes.

An anti-atherogenic effect of Schistosoma mansoni infections in mice associated with a parasite-induced lowering of blood total cholesterol

In affluent societies the prevalences of so-called 'Western' diseases such as atherosclerosis, allergies and autoimmune disorders appear to have increased, while many diseases caused by communicable infections are now relatively less common. To test whether there may be a causal relationship we examined the effects of Schistosoma mansoni infections in mice that develop cardiovascular pathology as a result of a genetic deficiency in apolipoprotein E (apoE-/-). The development of atherosclerotic lesions in the aortic arch and brachiocephalic artery of the apoE-/- mice was reduced by approximately 50% in mice with the parasitic infection, when comparison was made with uninfected control mice fed the same diet. Observations on S. mansoni-infected conventional laboratory mice indicate that patent schistosome infections could be counteracting the effects of an atherogenic diet by modulating host lipid metabolism and inducing a reduction in blood total cholesterol concentrations.

Plasmin-mediated fibroblast growth factor-2 mobilisation supports smooth muscle cell proliferation in human saphenous vein

The focus of this study was identification of the contribution of the plasminogen activator-plasmin system to smooth muscle cell proliferation and migration in human saphenous vein. Segments of human saphenous vein were grown in organ culture for up to 14 days. Smooth muscle cell proliferation and migration were measured by incubating vein segments in bromodeoxyuridine, and smooth muscle cell death was detected by in situ end-labelling. Tissue-type (tPA) and urokinase-type (uPA) plasminogen activator enzymic activities were detectable in cultured saphenous vein segments, and were concentrated in focal zones. Inhibition of plasmin activity with alpha-N-acetyl-L-lysine methyl ester (NALME) or of uPA activity with a neutralising antibody caused significant decreases in smooth muscle cell proliferation in the media and the intima, but no significant changes in smooth muscle cell migration. Intimal thickness was also significantly decreased. Incubation with plasminogen or plasmin caused fibroblast growth factor-2 (FGF2) to be released into the medium. Addition of FGF2 to segments cultured with NALME reversed the inhibition of smooth muscle cell proliferation, and blocking the activity of FGF2 with a neutralising antibody caused a significant decrease in medial smooth muscle cell proliferation. These data suggest that plasmin mobilises FGF2 bound to the extracellular matrix of human saphenous vein, so that it can support smooth muscle cell proliferation and intimal thickening.

Modulation of smooth muscle proliferation in rat carotid artery by platelet-derived mediators and fibroblast growth factor-2

Endothelial denuding injury to the rat carotid artery stimulates smooth muscle cell proliferation in the tunica media. Fibroblast growth factor-2 (FGF2) is responsible for a significant portion of this proliferation but other factors may contribute, particularly those released from adherent platelets. We therefore tested the effects of a range of platelet-derived factors. After filament injury, which minimises FGF2 release, the proliferation rate in thrombocytopaenic rats was decreased by 74% (P < 0.02). After balloon injury, antibody neutralisation of platelet-derived growth factor (PDGF) caused a 27% decrease in proliferation (P < 0.05), while inhibition of histamine H(1) receptors caused a 53% increase (P < 0.05). When filament injury was performed 1 h after FGF2 injection, the proliferation rate increased from 2.3+/-0.7 to 32.8+/-2.7% (P < 0.001), while filament injury alone caused a proliferation rate of only 18.3+/-2.9% (P < 0.01 versus filament plus FGF2). These data suggest that platelet-derived factors interact with FGF2 that is adsorbed to the vessel wall in the control of smooth muscle cell proliferation, and that the net effect of platelets is to stimulate smooth muscle cell proliferation. PDGF, but no other platelet agonist tested, contributes to that stimulation.

Urologic laparoscopy

Urologic laparoscopy initially was confined to a diagnostic role or the treatment of benign conditions. Many of these initial procedures, however, have been abandoned because they offered no significant benefit over open surgery. The treatment of urologic malignancies, however, recently has emerged as the most common indication for laparoscopic urologic surgery. Maturing data for laparoscopic radical nephrectomy, nephroureterectomy and partial nephrectomy demonstrate equivalent oncologic results. Newer applications such as laparoscopic radical prostatectomy are evolving. Despite these data demonstrating many advantages as compared with open techniques, urologists have been slow to include laparoscopy in their practice. This reluctance has been seen in other disciplines and is no doubt, at least in part, caused by the steep learning curve. Laparoscopic management of urologic malignancies is complicated and difficult to learn. In a multi-institutional review of laparoscopic complications, 71% of the complications occurred in the first 20 cases. The risk of complications and operative time significantly declines with experience, however. Higashihara et al reported a decline in laparoscopic operative time to levels comparable to open radical nephrectomy. The learning curve seems to be approximately 30 to 40 cases. The scope and practice of urology does not provide a common procedure of relatively low complexity such as the general surgical cholecystectomy or gynecologic tubal ligation to facilitate the adoption of laparoscopy by urologists. Nevertheless, evolving techniques and equipment coupled with the incorporation of laparoscopic training in residency and fellowship programs will help secure laparoscopy a prominent place in the treatment of urologic malignancy.

Physical and transcriptional map of the hereditary inclusion body myopathy locus on chromosome 9p12-p13

Hereditary inclusion body myopathy (HIBM) is a group of neuromuscular disorders characterised by adult-onset, slowly progressive distal and proximal muscle weakness and typical muscle pathology. Previously, we have mapped the gene responsible for a recessive form of HIBM to chromosome 9p1 and narrowed the interval to one single YAC clone of 1 Mb in size. As a further step towards the identification of the HIBM gene, we have constructed a detailed physical and transcriptional map of this region. A high resolution BAC contig that includes the HIBM critical region, flanked by marker 327GT4 and D9S1859, was constructed. This contig allowed the precise localisation of 25 genes and ESTs to the proximal region of chromosome 9. The expression pattern of those mapped genes and ESTs was established by Northern blot analysis. In the process of refining the HIBM interval, 13 new polymorphic markers were identified, of which 11 are CA-repeats, and two are single nucleotide polymorphisms. Certainly, this map provides an important integration of physical and transcriptional information corresponding to chromosome 9p12-p13, which is expected to facilitate the cloning and identification not only of the HIBM gene, but also other disease genes which map to this region.

Three dimensional configuration of the secretory pathway and segregation of secretion granules in the yeast Saccharomyces cerevisiae

The structural elements of the secretory pathway in the budding yeast Saccharomyces cerevisiae were analyzed by 3D stereo-electron microscopy using relatively thick sections in which membranes were selectively impregnated. In a wild-type strain, tubular networks of various sizes and staining properties were distributed throughout the cytoplasm. As a rule, wide-meshed, lightly stained polygonal networks were connected to more or less fenestrated sheets of endoplasmic reticulum (ER). Some of these networks were continuous with more intensely stained networks and narrower meshes that displayed at their intersections nodular dilations that progressively increased in size and staining properties to reach those of secretion granules. Such networks presumably corresponded to Golgi elements. Indeed, stacked cisternae typical of the mammalian Golgi apparatus are rarely found in wild-type cells. However, if it is assumed that the Golgi apparatus plays a key role in the segregation and maturation of secretion granules, then tubular networks with nodular dilations should be equivalent to parts of this organelle. In correlation with the increase in size and density of the nodules there was a decrease in diameter and staining intensity of the interconnecting tubules. These results parallel observations on the formation of secretory granules in mammalian cells and suggest that the segregation of secretory material is concomitant with the progressive perforation and tubulization of previously unperforated sheets. When the sec21-3 thermosensitive mutant was examined at the nonpermissive temperature (37°C), the secretory pathway was blocked at exit from the ER, which started to accumulate as clusters of narrow, anastomosed, unperforated ribbon-like elements. When the block was released by shifting down to permissive temperature (24°C), tubular networks of various sizes and caliber, presumably Golgi in nature, formed as soon as 5 minutes after release of the block. At later time intervals, granules of various sizes and densities appeared to be released by rupture of these tubular networks or even to form at the edges of ER fenestrae. These observations support a dynamic maturation process in which the formation of secretion granules occurs by means of an oriented series of membrane transformations starting at the ER and culminating with the liberation of secretion granules from Golgi networks.

The ARF exchange factors Gea1p and Gea2p regulate Golgi structure and function in yeast

The Sec7 domain guanine nucleotide exchange factors (GEFs) for the GTPase ARF are highly conserved regulators of membrane dynamics. Their precise molecular roles in different trafficking steps within the cell have not been elucidated. We present a functional analysis of two members of this family, Gea1p and Gea2p, in the yeast Saccharomyces cerevisiae. Gea1p and Gea2p can functionally replace each other, but at least one is necessary for viability. Temperature sensitive gea mutants were generated and found to have defects in ER-Golgi and intra-Golgi transport. Similar to mutants in COPI subunits in yeast, gea mutants had a cargo-selective secretion defect, in that some proteins continued to be secreted whereas others were blocked in the ER or early Golgi. Like yeast arf mutants, the rate of transport of those proteins that continued to be secreted was slowed. In addition, the structure of Golgi elements was severly perturbed in gea mutants. We conclude that Gea1p and Gea2p play an important role in the structure and functioning of the Golgi apparatus in yeast.

Controlling small guanine-nucleotide-exchange factor function through cytoplasmic RNA intramers

ADP-ribosylation factor (ARF) GTPases and their regulatory proteins have been implicated in the control of diverse biological functions. Two main classes of positive regulatory elements for ARF have been discovered so far: the large Sec7/Gea and the small cytohesin/ARNO families, respectively. These proteins harbor guanine-nucleotide-exchange factor (GEF) activity exerted by the common Sec7 domain. The availability of a specific inhibitor, the fungal metabolite brefeldin A, has enabled documentation of the involvement of the large GEFs in vesicle transport. However, because of the lack of such tools, the biological roles of the small GEFs have remained controversial. Here, we have selected a series of RNA aptamers that specifically recognize the Sec7 domain of cytohesin 1. Some aptamers inhibit guanine-nucleotide exchange on ARF1, thereby preventing ARF activation in vitro. Among them, aptamer M69 exhibited unexpected specificity for the small GEFs, because it does not interact with or inhibit the GEF activity of the related Gea2-Sec7 domain, a member of the class of large GEFs. The inhibitory effect demonstrated in vitro clearly is observed as well in vivo, based on the finding that M69 produces similar results as a dominant-negative, GEF-deficient mutant of cytohesin 1: when expressed in the cytoplasm of T-cells, M69 reduces stimulated adhesion to intercellular adhesion molecule-1 and results in a dramatic reorganization of F-actin distribution. These highly specific cellular effects suggest that the ARF-GEF activity of cytohesin 1 plays an important role in cytoskeletal remodeling events of lymphoid cells.

Atherosclerotic plaque rupture in the apolipoprotein E knockout mouse

The rupture of an atherosclerotic plaque is the main underlying cause of coronary artery thrombotic occlusion and subsequent myocardial infarction, but research into the causes and treatment of plaque rupture is hampered by the lack of a suitable animal model. Although complex atherosclerotic plaques can be induced in a number of experimental animal systems, in none of these is plaque rupture an established feature. We have surveyed branch points in the carotid arteries and aortas of apolipoprotein E knockout mice fed a diet supplemented with 21% lard and 0.15% cholesterol for up to 14 months. Six male and five female mice were used. Four of the male mice and four of the female mice died, after 46+/-3 weeks of feeding (range 37-59 weeks). Lumenal thrombus associated with atherosclerotic plaque rupture was observed in three male and all four female mice. In six of these seven mice, an atherosclerotic plaque rupture was found where the brachiocephalic artery branches into the right common carotid and right subclavian arteries. The ruptures were characterised by fragmentation and loss of elastin in the fibrous caps of relatively small and lipid-rich plaques overlying large complex lesions, with intraplaque haemorrhage. Immunocytochemical analysis revealed loss of smooth muscle cells from ruptured caps. These data suggest that long-term fat-feeding of apolipoprotein E knockout mice is a useful and reproducible model of atherosclerotic plaque rupture, and that these ruptures occur predominantly in the brachiocephalic artery.

Effects of probucol on rat carotid artery responses to balloon catheter injury

Balloon catheter injury to the rat common carotid artery has been widely used for testing potential therapies for post-angioplasty restenosis. However, the model has become somewhat discredited because a number of drugs that inhibit intimal thickening, measured 14 days after balloon catheter injury, have been found to be ineffective in clinical trials. Probucol has recently been shown to reduce the incidence of post-angioplasty restenosis in a number of small clinical trials, making it possible to reassess the validity of the rat balloon injury model. The effects of probucol on the underlying causes of intimal thickening in balloon-injured rat carotid arteries were quantified. Probucol inhibited medial smooth muscle cell proliferation by 23% on day 4 after injury (P=0.009), and by 65% on day 10 after injury (P=0.026). Smooth muscle cell migration was reduced by 64% (P=0.008) in probucol-treated animals. In marked contrast, intimal smooth muscle cell proliferation was significantly increased by 41% (P=0.024) by probucol. There was no significant effect on intimal thickening or smooth muscle cell death. These data suggest that drugs that inhibit both medial smooth muscle cell proliferation and migration in the rat balloon injury model may prove useful in the treatment of post-angioplasty restenosis.

Clinical pathways involving general practice--a new approach to integrated health care?

The Mater Mothers' Hospital, South Brisbane recently identified a number of difficulties with the maternity share-care program it runs with 1100 local GPs. This paper describes an integration approach developed at the Mater which has addressed these problems via the use of clinical management guidelines across the whole episode of care, the provision of a patient held record/pathway as a clinical practice prompt, clear communication and information management protocols between hospital and general practice, and the provision of continuing medical education for share-care practitioners.

Home phototherapy for neonatal jaundice--technology and teamwork meeting consumer and service need

32 babies with uncomplicated physiological jaundice received home phototherapy from a hospital/community team in southern Brisbane. All babies showed acceptable reductions in their serum bilirubin on home therapy, and none required hospital re-admission for phototherapy. Their families were highly satisfied with the home program, and recorded high levels of confidence in their therapeutic responsibilities. Community providers were able to deliver a high quality 24-hour service, integrated with appropriate neonatology support. The cost of delivering the home program was significantly less than a comparable hospital stay.

Regulators and effectors of the ARF GTPases

The small G proteins of the ARF family are key regulators of membrane dynamics. Many functions of ARF proteins in cells are being revealed by studies of their regulators and effectors. Significant progress has been made over the past year, with the identification of a surprisingly large family of novel ARF GTPase-activating proteins. In addition, two new classes of effectors, the PIP kinases and a novel family of monomeric coat-like proteins have been discovered.