Role of UDP-Glycosyltransferase (ugt) Genes in Detoxification and Glycosylation of 1-Hydroxyphenazine (1-HP) in Caenorhabditis elegans

Caenorhabditis elegans is a useful model organism to study the xenobiotic detoxification pathways of various natural and synthetic toxins, but the mechanisms of phase II detoxification are understudied. 1-Hydroxyphenazine (1-HP), a toxin produced by the bacterium Pseudomonas aeruginosa, kills C. elegans. We previously showed that C. elegans detoxifies 1-HP by adding one, two, or three glucose molecules in N2 worms. Our current study evaluates the roles that some UDP-glycosyltransferase (ugt) genes play in 1-HP detoxification. We show that ugt-23 and ugt-49 knockout mutants are more sensitive to 1-HP than reference strains N2 or PD1074. Our data also show that ugt-23 knockout mutants produce reduced amounts of the trisaccharide sugars, while the ugt-49 knockout mutants produce reduced amounts of all 1-HP derivatives except for the glucopyranosyl product compared to the reference strains. We characterized the structure of the trisaccharide sugar phenazines made by C. elegans and showed that one of the sugar modifications contains an N-acetylglucosamine (GlcNAc) in place of glucose. This implies broad specificity regarding UGT function and the role of genes other than ogt-1 in adding GlcNAc, at least in small-molecule detoxification.

[Vasectomy under local anesthesia, retrospective evaluation of patient satisfaction in CH Annecy Genevois]

Contraceptive vasectomy is a male sterilization technique by interrupting the continuity of the vas deferens. The primary endpoint of our study was to evaluate patients' feelings of vasectomy under local anesthesia. We collected responses from 108 patients who had a vasectomy under local anesthesia at the Center Hospitalier Annecy Genevois between January 1, 2020 and April 30, 2022. The average age of patients at the time of the vasectomy was 40years old. Patients were satisfied with the level of information before vasectomy for 104 of them (96%). The level of pain felt during the intervention evaluated by Visual Analog Scale had an average of 3.4/10 (standard deviation 2.4). The degree of satisfaction during the procedure was excellent/good for 103 patients (95%). In the follow-up, we reported 10 patients (10%) with a complication (hematoma, infection or healing problem). The retrospective evaluation found 103 patients (95%) who would repeat the procedure under the same modalities and 106 patients (98%) who would recommend vasectomy under local anesthesia to a relative/friend. Vasectomy under local anesthesia is increasingly common, so it is important to assess the feelings of patients with this modality. Our study had the advantage of bringing together a large number of patients over a short period with several different operators. Overall satisfaction with the hospitalization process and the procedure was very satisfactory. The patient journey was significantly simplified with local anesthesia instead of general anesthesia. LEVEL OF EVIDENCE: 4.

Very long-term outcomes of patients undergoing catheter ablation of atrial fibrillation: a systematic review and meta-analysis

Background

The efficacy of catheter ablation of atrial fibrillation (AF) is reported to stabilise at 5-year, but most studies report up to 3-year-outcomes only.

Objective

To perform a systematic review and meta-analysis of outcomes at 5-years following AF ablation.

Methods

We searched PubMed and Embase for studies reporting on ≥5-year outcomes following AF ablation, including freedom from atrial arrhythmia, all-cause death, stroke, and major bleeding. All meta-analyses were performed using the “meta” package in R with pooled incidence calculated using log transformation.

Results

Among 5,764 studies screened, 58 (n=41,344 patients) were included for analysis. The pooled mean age was 60.3y, 68.7% male, 78.4% paroxysmal AF, and radiofrequency was the most common ablation energy (72.4%). Most (51.5%) patients had hypertension, but the pooled rates of other comorbidities were low (heart failure: 9.0%, coronary artery disease: 12.8%, diabetes: 11.0%, and previous stroke: 8.5%). Pooled incidence of freedom from atrial arrhythmia at 5-years was 47.6% (95% CI 43.8%-51.6%, I2=98.4%) after a single procedure and increased to 64.3% (95% CI 59.6%-69.3%, I2=98.3%) after multiple procedures (Figure 1). The incidence was higher among patients with paroxysmal compared with non paroxysmal AF (55.9% vs. 28.7% and 82.2% vs. 47.6% after single and multiple procedures respectively). Retrospective studies reported slightly higher incidence of arrhythmia freedom (single procedure: 51.2% vs. 46.7%; multiple procedures: 66.9% vs. 61.9%) than did prospective studies. Few studies reported outcomes other than atrial arrhythmia free survival at 5-years (n=14) and incidences of these outcomes could only be pooled for multiple procedures. Pooled incidences of death, stroke, and major bleeding at 5-years were 8.0% (95% CI 4.2%-15.2%, I2=95.8%), 2.3% (95% CI 1.4%-3.6%, I2=72.9%), and 1.1% (95% CI 0.6%-1.8%, I2=32.5%), respectively (Figure 2).

Conclusion

At five-years, only up to 65% of patients undergoing AF ablations remained free from atrial arrhythmia although there was significant heterogeneity among individual studies. Encouragingly, these patients had low risk of dying, experiencing a stroke or major bleeding (all incidences<10%).

Funding Acknowledgement

Type of funding sources: None.

Long-term outcomes of 265,737 patients hospitalised with atrial fibrillation and atrial flutter from 2008 to 2015

Background

Atrial fibrillation/atrial flutter (AF/AFL) hospitalisations are common, however, little is known about the long-term outcomes of these episodes.

Objective

To examine the incidence of mortality, all-cause and cause-specific re-hospitalisations at up to 8 years after a hospitalisation for AF/AFL.

Methods

Unique patients hospitalised with a primary diagnosis of AF/AFL from 2008–2015 were identified using nation-wide hospitalisation data from Australia and New Zealand. All-cause mortality was the primary outcome. Secondary endpoints included all-cause and cause-specific re-hospitalisations. Results were reported as incident rate per 100 patient-years.

Results

We included 265,737 patients (mean age 69.9±13.9y, female 45.2%, elective 28.7%). The median length of stay was 1 day (Interquartile range [IQR] 0–4 days) and the median CHA2DS2-VASc score was 2 (IQR 1–2). During the index hospitalisation, 9,837 (3.7%) patients underwent catheter or surgical ablation and 52,634 (19.8%) underwent cardioversion. During the median follow-up time of 3.4 years (range 0–8.0 years), 53,669 patients died (incident rate of 5.7/100 patient-years) with a survival probability gradually decreasing from 92.8% (95% CI 92.7–92.9%) at 1-year to 65.4% (95% CI 64.9–65.8%) at 8-years post-discharge (Table 1 and Figure 1). All-cause re-hospitalisations occurred in 210,118 patients (incident rate of 22.2/100 patient-years) with a rehospitalisation-free survival probability of 7.1% (95% CI 6.9—7.3%) at the end of follow-up. Unplanned re-hospitalisations occurred more frequently than planned episodes (incident rate of 17.2 vs. 16.6/100 patient-years respectively). AF/AFL accounted for 25.1% of all-cause re-hospitalisations (incident rate of 8.9/100 patient-years) and the probability of freedom from re-hospitalisations for AF/AFL was 55.4% (95% CI 55.0–55.8%) at 8-years. Incident rates of re-hospitalisations for catheter ablation (1.5/100 patient-years), stroke (1.6/100 patient-years), heart failure (2.7/100 patient-years), and acute myocardial infarction (1.0/100 patient-years) were low. In subgroup analyses, worse survival was observed in female patients, older age groups, patients with comorbid heart failure, hypertension, diabetes, and those who did not undergo ablation during the index hospitalisation.

Conclusion

Nearly two-thirds of patients were surviving by 8-years following an AF/AFL hospitalisation with a low rate of re-hospitalisations for stroke, heart failure, and myocardial infarction. However, re-hospitalisations for recurrent atrial arrhythmia were common. Efforts to reduce re-hospitalisations, especially unplanned encounters, are required to improve patient outcomes.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): National Heart Foundation of Australia

Trends in complications and mortality following catheter ablation of atrial fibrillation: results from 22,582 ablations in Australia and New Zealand from 2010 to 2015

Background

Recent studies from the United States report rising rates of in-hospital complications and mortality following catheter ablation of atrial fibrillation (AF) but whether such a trend is observed in other populations is uncertain.

Purpose

To examine the trends in complications and mortality following AF ablations up to 30 days after discharge in Australia and New Zealand (ANZ) using nationwide data.

Methods

All patients ≥18y undergoing catheter ablation of AF from 2010–2015 were identified using hospitalisation data from all public and most private hospitals in ANZ. The primary endpoint was one or more procedural complications during the hospital stay or within 30 days of discharge. The secondary endpoints were mortality and other specific complications. Unadjusted trend was evaluated using Cochran-Armitage test while that of complications, adjusting for differences in other characteristics, was evaluated using multivariate logistic regression with the year of ablation modelled as a continuous variable. Results are reported as odd ratios (OR) and 95% confidence intervals (CI).

Results

A total of 22,582 AF ablations were included (mean age 62.2±11.6y, 29.1% female, 94.4% elective procedures). The number of ablations increased by 26.4% during the study period (3,097 in 2010 to 3,915 in 2015). Rates of heart failure (8.98% to 10.09%, p for trend=0.010), diabetes (4.52% to 12.46%, p<0.001), chronic kidney disease (2.36% to 4.29%, p<0.001) significantly increased over time but that of hypertension decreased (15.27% to 12.29%, p<0.001). The incidence of overall complications (6.55% in 2010 to 6.67% in 2015, OR 0.99, 95% CI 0.96–1.03) was unchanged during the study period (Figure 1A). When individual complications were considered, mortality rate was low with no statistically significant change with time (0.19% to 0.15%, OR 1.03, 95% CI 0.84–1.28) (Figure 1A) while the rate of acute kidney injury (0.23% to 0.51%, OR 1.17, 95% CI 1.02–1.34) increased and that of venous thromboembolism (0.16% to 0.0%, OR 0.71, 95% CI 0.54–0.94) decreased (Figure 1B). Though the incidence of any bleeding (4.49% to 3.98%, OR 0.97, 95% CI 0.93–1.01) was unchanged, that of major bleeding requiring blood transfusion (0.97% to 0.64%, OR 0.87, 95% CI 0.79–0.96) declined significantly (Figure 1B). No significant trend was observed in other complications or when in-hospital (5.13% to 5.21%, OR 1.00, 95% CI 0.97–1.04) and post-discharge (1.55% to 1.63%, OR 0.97, 95% CI 0.91–1.03) complications were separately evaluated.

Conclusions

Though more patients with heart failure, diabetes and chronic kidney disease underwent catheter ablation of AF over time in ANZ, the overall complication rate was unchanged with a significant decrease in the incidences of major bleeding and venous thromboembolism. However, rate of acute kidney injury nearly doubled, and this could be a potential target for efforts to further improve procedural safety.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): The National Heart Foundation of Australia

Differences between public and private hospitals in complications following catheter ablation of atrial fibrillation: a cohort study in Australia

Background

Comparing outcomes of care between public and private hospitals is critical to inform patients and improve care quality.

Purpose

To compare complication rates following catheter ablation of atrial fibrillation (AF) up to 30-days post discharge between public and private hospitals.

Methods

We included patients ≥18 years who underwent AF ablation in the Australian states of New South Wales, Queensland, Victoria, and Western Australia from 2010–2015. The primary outcome was the occurrence of any complication up to 30-days after discharge. The association between provider type and the risk of complications was examined using logistic regression with inverse probability of treatment weighting (IPTW) propensity scores to account for differences in measured confounders. The minimum strength of association required for an unmeasured confounder to nullify any observed association was estimated using the E value.

Results

We identified 18,074 AF ablations during the study period (mean age 62.3±11.4y, 28.8% female, 78.4% performed in private hospitals). Patients ablated at public hospitals were younger (59.3 vs. 63.1y, p<0.001) but had higher rates of heart failure (10.3% vs. 7.7%, p<0.001), diabetes (10.9% vs. 7.9%, p<0.001), chronic kidney disease (4.9% vs. 2.2%, p<0.001), and chronic lung diseases (4.2% vs. 3.6%, p=0.046) than those at private hospitals. The unadjusted rate of complications was higher in publics hospitals compared with private ones (7.59% vs. 5.26%, p<0.001). After IPTW, there was good covariate balance with a median standardised difference of 0.006 (range 0.0–0.032) and the adjusted difference in procedural complication rates between two sectors remained significant (OR=1.46, 95% CI 1.24–1.73). The difference was mainly driven by an elevated risk of complications requiring cardiac surgery (OR=3.85, 95% CI 1.35–10.98), acute kidney injury (OR=2.95, 95% CI 1.12–7.74), cardiorespiratory failure (OR=2.69, 95% CI 1.19–6.04), postprocedural infection (OR=2.50, 95% CI 1.28–4.86), and bleeding (OR=1.26, 95% CI 1.02–1.56) (Figure 1). The disparity in the complication rates persisted when in-hospital (OR=1.41, 95% CI 1.16–1.70) and post-discharge (OR=1.52, 95% CI 1.12–2.07) complications were analysed separately. The E value was 1.79, suggesting that the disparity might plausibly be explained by unmeasured confounders.

Conclusion

AF ablation at a public hospital was associated with a 46% higher risk of complications compared with ablation at a private hospital, mainly driven by a higher risk of complications requiring cardiac surgery, acute kidney injury, cardiorespiratory failure, infections, and bleeding. The disparity could be due to differences in care quality between two sectors or explained by unmeasured confounders such as higher procedural complexity in public hospitals.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): The National Heart Foundation of Australia

Memory advancement by intranasal insulin in type 2 diabetes (MemAID) randomized controlled clinical trial: Design, methods and rationale

BACKGROUND

Type 2 diabetes mellitus (T2DM) accelerates brain aging and increases the risk for dementia. Insulin is a key neurotrophic factor in the brain, where it modulates energy metabolism, neurovascular coupling, and regeneration. Impaired insulin-mediated brain signaling and central insulin resistance may contribute to cognitive and functional decline in T2DM. Intranasal insulin (INI) has emerged as a potential therapy for treating T2DM-related cognitive impairment.

METHODS/DESIGN

Ongoing from 2015, a prospective, two-center, randomized, double-blind, placebo-controlled trial of 210 subjects (120 T2DM and 90 non-diabetic older adults) randomized into four treatment arms (60 T2DM-INI, 60 T2DM-Placebo, 45 Control-INI, and 45 Control-Placebo) evaluating the long-term effects of daily intranasal administration of 40 International Units (IU) of human insulin, as compared to placebo (sterile saline) over 24 weeks and 24 weeks of post-treatment follow-up. Study outcomes are: 1) long-term INI effects on cognition, daily functionality, and gait speed; 2) identifying a clinically relevant phenotype that predicts response to INI therapy; 3) long-term safety.

CONCLUSION

This study addresses an important knowledge gap about the long-term effects of intranasal insulin on memory and cognition in older people with T2DM and non-diabetic controls, and may provide a novel therapeutic target for prevention and treatment of cognitive and functional decline and dementia. Trial Registration NCT02415556.

P347Complications of catheter ablation for atrial fibrillation: a nation-wide study in Australia and New Zealand

Background

It is important to investigate complications of catheter ablation for atrial fibrillation (AF) - an increasingly common procedure - to inform patients and guide efforts to improve procedural quality. However, clinical trials and registries are limited by selection bias, while existing population-based studies either lack nation-wide data, or fail to report post-discharge complications. The timing and impact of these complications are also poorly understood.

Purpose

To obtain unbiased and comprehensive estimates of complications of AF ablations using national data from Australia and New Zealand. We also evaluated the impact of in-hospital complications on the length of stay and assessed the timing of post-discharge complications.

Methods

We included patients aged ≥18 years undergoing catheter ablation with a primary diagnosis of AF between 2010–2015 in all public and most private hospitals in Australia and New Zealand. The primary outcome was the occurrence of major complications in-hospital or up to 30-days after discharge. We identified major complications based on a literature review and expert clinical opinion and defined these using International Classification of Diseases – 10th revision, Australian Modification diagnoses codes and Australian Classification of Health Interventions procedure codes. We determined the impact of in-hospital complications on the length of stay, adjusting for other covariates, by using negative binomial regression, and reported results as incident rate ratio (IRR) and 95% confidence intervals (CI). Time to first post-discharge complication was evaluated using Kaplan Meier survival analysis.

Results

A total of 20,057 AF ablations were included (mean age 62.1±11.6 y, 56.7% ≤65 years old; 29.2% female; median length of stay 1 day). Of these, major complications occurred in 6.3% procedures (4.6% occurring in-hospital and a further 2.0% occurring in the 30-day post discharge). The most common complications were bleeding or haematoma formation and perforation (primarily pericardial effusion), which accounted to 60.3% and 14.3% of all complications, respectively. Rate of procedure-related deaths was 0.1%. Occurrence of an in-hospital complication more than doubled the length of stay (IRR: 2.3, 95% CI 2.2–2.4) with complications requiring cardiac surgery (IRR 4.5, 95% CI 3.2–6.4) and vascular injuries (IRR 3.9, 95% CI 3.1–4.9) having the length of stay prolonged the most (Figure 1A). In the first-week, 67.3% of post-discharge complications had occurred, and this number reached 95% within three-weeks (Figure 1B).

Conclusions

Major complications after AF ablation were common. In-hospital complications doubled the length of stay. Approximately 30% of complications occurred after discharge with the risk highest in the first seven days. Efforts to reduce complications should focus on reducing the incidence of bleeding and pericardial effusions which counted for more than 75% of all complications.

Acknowledgement/Funding

National Heart Foundation of Australia, The Hospital Research Foundation

Post-mortem prediction of primal and selected retail cut weights of New Zealand lamb from carcass and animal characteristics

Post-mortem measurements (cold weight, grade and external carcass linear dimensions) as well as live animal data (age, breed, sex) were used to predict ovine primal and retail cut weights for 792 lamb carcases. Significant levels of variance could be explained using these predictors. The predictive power of those measurements on primal and retail cut weights was studied by using the results from principal component analysis and the absolute value of the t-statistics of the linear regression model. High prediction accuracy for primal cut weight was achieved (adjusted R(2) up to 0.95), as well as moderate accuracy for key retail cut weight: tenderloins (adj-R(2)=0.60), loin (adj-R(2)=0.62), French rack (adj-R(2)=0.76) and rump (adj-R(2)=0.75). The carcass cold weight had the best predictive power, with the accuracy increasing by around 10% after including the next three most significant variables.

Comparison of clinical and cone beam computed tomography measurements to diagnose furcation involvement

AIM

This study aimed to determine the degree of discrepancy between clinical measurement of furcation involvement (FI) and cone beam computed tomography image analysis of multirooted teeth.

METHODS

FI measurements obtained from clinical records were compared to CBCT images of the same teeth to determine the degree of discrepancy between CBCT FI grading and clinical FI grading.

RESULTS

Of the hundred and fifty-four sites analysed, 22% of FI measurements from probing and CBCT were in agreement. Fifty-eight percent of clinical FI recordings were overestimated, and 20% were underestimated when compared to CBCT analysis.

CONCLUSION

Clinical recording of FI is both over and underestimated compared to CBCT analysis. This was highest for probing recording grade I furcation involvement where it was highly overestimated. The occurrence of over and under estimation of FI will affect the assignment of prognosis to multirooted teeth, which can influence treatment planning for periodontal therapy and may result in inappropriate treatment.

The hiv tat gene is a promoter of epidermal skin tumors

Human immunodeficiency virus (HIV) infected patients have a very high incidence (>90%) of neoplastic and non-neoplastic skin disorders. The proliferative lesions frequently involve the epidermis and include squamous and basal cell carcinomas, and the papulosquamous diseases of seborrheic dermatitis and psoriasis. Although the role played by HIV in the development of these proliferative skin lesions is not clear, there are several lines of evidence suggesting that HIV may play a causative role. We show that transgenic mice carrying the HIV tat gene under the control of the viral LTR constitutively express the tnt gene in keratinocytes. When a single subthreshold dose of a carcinogen initiator is topically applied to these mice, tumor promoters are no longer required to induce the development of epidermal skin tumors, suggesting that Tat expression in keratinocytes is capable of substituting for phorbol ester tumor promoters in the two-step carcinogenesis skin cancer model. Together, Tat and phorbol ester have additive effects in promoting tumors in transgenic mice first initiated with carcinogens. We conclude that although Tat alone is insufficient to cause epidermal tumors, it functions as a tumor promoter and predisposes these mice to develop tumors following an initiating event.

Influence of diabetes on endothelial cell response during sepsis

AIMS/HYPOTHESIS

Several endothelial pathways of cell adhesion, coagulation and vascular endothelial growth factor (VEGF) signalling are activated during sepsis. The objective of this analysis was to investigate the influence of diabetes on biomarkers of endothelial cell activation in sepsis.

METHODS

This was a prospective observational cohort study of a convenience sample of adult patients (age ≥ 18 years) for whom infection was clinically suspected and who presented to an urban tertiary care emergency department between February 2005 and November 2008. We investigated the association of diabetes and sepsis with various endothelial activation biomarkers of cell adhesion (E-selectin, vascular cell adhesion molecule 1 [VCAM-1] and intercellular adhesion molecule 1 [ICAM-1]), coagulation (plasminogen activator inhibitor 1 [PAI-1]) and VEGF signalling (soluble fms-like tyrosine kinase-1 [sFLT-1]).

RESULTS

A total of 207 patients (34% with sepsis, 32% with severe sepsis and 34% with septic shock) were studied, including 63 (30%) with diabetes. Compared with patients without diabetes, patients with diabetes had significantly increased E-selectin and sFLT-1 levels overall; this was most pronounced during septic shock in the stratified analysis. Multivariate models including age, sex, sepsis severity and other variables as potential covariates confirmed the association of diabetes with elevated circulating plasma levels of E-selectin (standardised β 0.24, p < 0.001) and sFLT-1 (standardised β 0.19, p < 0.01), but there was no significant association with VCAM-1, ICAM-1 or PAI-1.

CONCLUSIONS/INTERPRETATION

During septic shock, patients with diabetes had higher levels of circulating biomarkers of endothelial cell adhesion (E-selectin) and VEGF signalling (sFLT-1). Future studies should address whether enhanced activation of the endothelium places patients with diabetes at increased risk for the development of sepsis and worsening morbidity and mortality.

Age-related changes in climbing behavior and neural circuit physiology in Drosophila

Identifying the cellular and molecular basis for functional decline remains key to understanding aging. To this end, we have characterized age-dependent changes in climbing and the electrophysiology of the giant fiber circuitry in wild type (Wt) and mutant flies with altered lifespan (methuselah and fragile-X). Our data demonstrate a gradual decline in climbing in Wt and methuselah flies aged 5-45 days. In contrast, fragile-X flies climbed poorly even at 5 days and failed completely at 45 days. We then examined whether synaptic transmission to indirect flight muscles along the giant fiber circuit was altered with aging. At 5 days, the dorsal longitudinal muscle (DLM) in Wt flies followed high frequency stimulation well (at 130 Hz or above). At 35 and 45 days, these flies only followed 60-80 Hz. Methuselah flies did not follow stimuli as well as the Wt flies did at 5 and 25 days, but they were similar to Wt flies at older ages. Fragile-X flies responded poorly even at 5 days (40 Hz) and worsened at 35 days (30 Hz). Unlike DLMs, the tergotrochanteral muscle followed high frequency stimuli relatively well in all genotypes, suggesting that the peripheral interneuron along the DLM pathway or the DLM muscular synapse is prone to age-dependent functional decline. These studies reveal subcellular structures as potential targets of aging, indicating that the giant fiber pathway can be used as a model circuit for quantitative studies of aging in flies as well as fly models of age-related human neurological disorders.

Health, disability, and life insurance experiences of working-age persons with multiple sclerosis

Working-age Americans with multiple sclerosis (MS) may face considerable financial insecurities when they become unable to work and lack the health, disability, and life insurance typically offered through employers. In order to estimate the rates of having these insurance policies, as well as how insurance status affects reports of financial stress, we conducted half-hour telephone interviews with 983 working-age persons across the US, who reported being diagnosed with MS. The interviews occurred from May through November 2005, and among the sampled individuals contacted and confirmed eligible, 93.2% completed the interview. The study population was largely female (78.9%), Caucasian (86.4%), married (68.6%), with at least some college education (71.5%), and unemployed (60.2%). Overall, 96.3% had some health insurance (40.3% with public health insurance, primarily Medicare), 56.7% had long-term disability insurance (36.4% with public programs), and 68.3% had life insurance. Notably, 27.4% indicated that, since being diagnosed with MS, health insurance concerns had significantly affected employment decisions. In addition, 16.4% reported considerable difficulty paying for health care, 27.4% put off or postponed seeking needed health care because of costs, and 22.3% delayed filling prescriptions, skipped medication doses, or split pills because of costs. Overall, 26.6% reported considerable worries about affording even basic necessities, such as food, utilities, and housing. Multiple Sclerosis 2007; 13: 534-546. http://msj.sagepub.com

DNA adducts among asphalt paving workers

OBJECTIVE

Asphalt is used extensively in the highway construction industry and contains a complex mixture of polycyclic aromatic hydrocarbons, some of which are known or suspected to be human carcinogens. Though numerous epidemiologic studies have described an excess cancer risk among asphalt workers, a causal relationship has not been established. Accordingly, the primary objective of this study was to use DNA adducts as a biomarker of biologically effective dose and determine whether DNA damage resulted from occupational exposure to asphalt among paving workers.

METHODS

Over a 12 month period, four peripheral blood samples (spring, summer, fall and winter) were obtained from 49 asphalt paving workers (169 samples) and 36 non-paving construction workers (103 samples). The spring, summer and fall samples were collected during the work-season, whereas the winter samples were collected during the off-season (due to the seasonality of paving work). Mononuclear white blood cells were isolated and analyzed for DNA adducts via the (32)P-postlabeling assay and generalized linear models were used to evaluate the DNA adduct data.

RESULTS

Among paving workers during the work-season, DNA adducts increased during each day of the workweek such that mean adduct levels were lowest on Mondays (3 adducts per 10(10) nucleotides) and highest on Fridays (46 adducts per 10(10) nucleotides). Additionally, a 3-fold difference in adduct burden was observed by paving task such that mean adduct levels were lowest among roller operators (7 adducts per 10(10) nucleotides) and highest among screedmen (23 adducts per 10(10) nucleotides). Using adducts as a measure of biologically effective dose, these findings (weekday trend and task-based differences) were consistent with a previous evaluation of absorbed dose in the same population. Adduct levels were not, however, higher among paving workers than among non-pavers. Adducts were also highest during the winter months, suggestive of a seasonal effect that has been observed in previous studies.

CONCLUSION

These findings indicate that adduct burden increased throughout the workweek among paving workers, suggesting that DNA damage may be associated with occupational exposure to hot-mix asphalt. However, the lack of contrast with non-paving workers, as well as the seasonal variation warrants additional investigation.

Evidence of transient enhancement to cognitive functioning in healthy young adults through environmental enrichment: implications for rehabilitation after brain injury

We examined preliminarily whether intensive mental activity can transiently enhance higher cognitive functioning in healthy adults. Ten healthy participants performed intensive mental activity for 2 weeks. The intervention entailed daily memorization of multiple prose passages and performance of demanding, speeded mental arithmetic.Neuropsychological testing was conducted before and after the intervention, using alternate forms. (The intervention and neuropsychological tests were different.) Findings in the intervention group were compared to those of a convenience control sample who had performed a near-identical neuropsychological assessment and follow-up in a different study, but who did not perform the intervention. The purpose was to rule out practice effects as the cause of any observed improvement in the intervention group. The intervention group showed improvement on six/eight measures. The non-intervention group showed improvement on only two. Results suggest cognitive capacity can be enhanced in healthy individuals after a period of intensive cognitive stimulation. Implications for rehabilitation are discussed.

Role of thioredoxin in the response of normal and transformed cells to histone deacetylase inhibitors

This study examines the basis of resistance and sensitivity of normal and transformed cells to histone deacetylase inhibitor (HDACi)-induced cell death, specifically the role of caspases and thioredoxin (Trx). An important attribute of HDACis is that they induce cancer cell death at concentrations to which normal cells are relatively resistant, making them well suited for cancer therapy. The mechanism underlying this selectivity has not been understood. In this study we found that the HDACi suberoylanilide hydroxamic acid (SAHA) and MS-275, a benzamide, cause an accumulation of reactive oxygen species (ROS) and caspase activation in transformed but not normal cells. Inhibition of caspases does not block HDACi-induced cell death. These studies provide a possible mechanism that can explain why normal but not certain transformed cells are resistant to HDACi-induced cell death. The HDACi causes an increase in the level of Trx, a major reducing protein for many targets, in normal cells but not in transformed cells. The SAHA-induced increase in Trx activity in normal cells is associated with no increase in ROS accumulation. Transfection of transformed cells with Trx small interfering RNA caused a marked decrease in the level of Trx protein with an increase in ROS, a decrease in cell proliferation, and an increase in sensitivity to SAHA-induced cell death. Thus, Trx, independent of the caspase apoptotic pathway, is an important determinant of resistance of cells to HDACi-induced cell death.

Inhalation and Dermal Exposure among Asphalt Paving Workers

The primary objective of this study was to identify determinants of inhalation and dermal exposure to polycyclic aromatic compounds (PACs) among asphalt paving workers. The study population included three groups of highway construction workers: 20 asphalt paving workers, as well as 12 millers and 6 roadside construction workers who did not work with hot-mix asphalt. During multiple consecutive work shifts, personal air samples were collected from each worker's breathing zone using a Teflon filter and cassette holder connected in series with an XAD-2 sorbent tube, while dermal patch samples were collected from the underside of each worker's wrist. All exposure samples were analyzed for PACs, pyrene and benzo[a]pyrene. Inhalation and dermal PAC exposures were highest among asphalt paving workers. Among paving workers, inhalation and dermal PAC exposures varied significantly by task, crew, recycled asphalt product (RAP) and work rate (inhalation only). Asphalt mix containing high RAP was associated with a 5-fold increase in inhalation PAC exposures and a 2-fold increase in dermal PAC exposure, compared with low RAP mix. The inhalation PAC exposures were consistent with the workers' proximity to the primary source of asphalt fume (paver operators > screedmen > rakers > roller operators), such that the adjusted mean exposures among paver operators (5.0 microg/m3, low RAP; 24 microg/m3, high RAP) were 12 times higher than among roller operators (0.4 microg/m3, low RAP; 2.0 microg/m3, high RAP). The dermal PAC exposures were consistent with the degree to which the workers have actual contact with asphalt-contaminated surfaces (rakers > screedmen > paver operators > roller operators), such that the adjusted mean exposures among rakers (175 ng/cm2, low RAP; 417 ng/cm2, high RAP) were approximately 6 times higher than among roller operators (27 ng/cm2, low RAP; 65 ng/cm2, high RAP). Paving task, RAP content and crew were also found to be significant determinants of inhalation and dermal exposure to pyrene. The effect of RAP content, as well as the fact that exposures were higher among paving workers than among millers and roadside construction workers, suggests that the PAC and pyrene exposures experienced by these paving workers were asphalt-related.

Urinary 1-Hydroxypyrene and Polycyclic Aromatic Hydrocarbon Exposure Among Asphalt Paving Workers

OBJECTIVES

Using urinary 1-hydroxypyrene (1-OHP) as a measure of total absorbed dose, the primary objective of this study was to evaluate the total effect of inhalation and dermal PAH exposures while considering other factors such as age, body mass index and smoking that may also have a significant effect on urinary 1-OHP.

METHODS

The study population included two groups of highway construction workers: 20 paving workers and 6 milling workers. During multiple consecutive workshifts, personal air and dermal samples were collected from each worker and analyzed for pyrene. During the same work week, urine samples were collected pre-shift, post-shift and at bedtime each day and analyzed for 1-OHP. Distributed lag models were used to evaluate the independent effect of inhalation and dermal exposures that occurred at each of several preceding exposure periods and were used to identify the relevant period of influence for each pathway.

RESULTS

The paving workers had inhalation (mean 0.3 micro g/m(3)) and dermal (5.7 ng/cm(2)) exposures to pyrene that were significantly higher than the milling workers. At pre-shift on Monday morning, following a weekend away from work, the pavers and millers had the same mean baseline urinary 1-OHP level of 0.4 micro g/g creatinine. The mean urinary 1-OHP levels among pavers increased significantly from pre-shift to post-shift during each work day, while the mean urinary 1-OHP levels among millers varied little and remained near the baseline level throughout the study period. Among pavers there was a clear increase in the pre-shift data during the work week, such that the average pre-shift level on day 4 (1.4 micro g/g creatinine) was 3.5 times higher than the average pre-shift results on day 1 (0.4 micro g/g creatinine). The results of the distributed lag model indicated that the impact of dermal exposure was approximately eight times the impact of inhalation exposure. Furthermore, dermal exposure that occurred during the preceding 32 h had a statistically significant effect on urinary 1-OHP, while the effect of inhalation exposure was not significant.

CONCLUSIONS

We found that distributed lag models are a valuable tool for analyzing longitudinal biomarker data and our results indicate that dermal contact is the primary route of exposure to PAHs among asphalt paving workers. An exposure assessment of PAHs that does not consider dermal exposure may considerably underestimate cumulative exposure and control strategies aimed at reducing occupational exposure to asphalt-related PAHs should include an effort to reduce dermal exposure.

Diagnostic utility of abbreviated fluency measures in Alzheimer disease and vascular dementia

BACKGROUND

Several studies indicate semantic fluency more sensitively discriminates patients with Alzheimer disease (AD) from normal elderly persons, with disproportionate impairment of semantic over phonemic fluency.

OBJECTIVE

To determine the ability of abbreviated fluency measures in the clinic setting (1-minute letter F and animal fluency tests) to detect AD, and to assess whether difference scores between these measures discriminate patients with AD and vascular dementia (VaD) from normal elderly persons.

METHODS

The authors studied patients with AD (n = 98) meeting National Institute of Neurological Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association criteria, VaD patients (n = 18) meeting National Institute of Neurological Disorders and Stroke-Association Internationale pour la Recherche et l'Enseignement en Neurosciences criteria, cognitively impaired but not demented patients (CIND; n = 25), vascular CIND patients (VCIND; n = 24), and normal control subjects (NCs; n = 46).

RESULTS

Analysis of covariance controlling for age, education, and overall impairment indicated all groups generated fewer animal names compared with NCs, whereas only VaD patients generated fewer letter F words compared with NCs. On standardized scores, patients with AD and CIND, unlike those with VCIND and VaD, scored significantly worse on the animal fluency test than on the letter F fluency test. The animal fluency test was superior in discriminating all patient groups from NCs. Positive likelihood ratios (PLRs) revealed animal fluency scores <15 were 20 times more likely in a patient with AD than in an NC (sensitivity = 0.88; specificity = 0.96). Letter F scores <4 discriminated VaD from AD patients (PLR = 4.0; sensitivity = 0.44; specificity = 0.90). Difference scores <0 (i.e., fewer animal than letter F words) discriminated patients with VCIND from those with CIND (PLR = 2.5; sensitivity = 0.32; specificity = 1.00).

CONCLUSIONS

A 1-minute semantic fluency test can assist in early detection of dementia in the memory clinic setting.

Histone deacetylase (HDAC) inhibitor activation of p21WAF1 involves changes in promoter-associated proteins, including HDAC1

Histone deacetylase (HDAC) inhibitors (HDACi) cause cancer cell growth arrest and/or apoptosis in vivo and in vitro. The HDACi suberoylanilide hydroxamic acid (SAHA) is in phase I/II clinical trials showing significant anticancer activity. Despite wide distribution of HDACs in chromatin, SAHA alters the expression of few genes in transformed cells. p21(WAF1) is one of the most commonly induced. SAHA does not alter the expression of p27(KIPI), an actively transcribed gene, or globin, a silent gene, in ARP-1 cells. Here we studied SAHA-induced changes in the p21(WAF1) promoter of ARP-1 cells to better understand the mechanism of HDACi gene activation. Within 1 h, SAHA caused modifications in acetylation and methylation of core histones and increased DNase I sensitivity and restriction enzyme accessibility in the p21(WAF1) promoter. These changes did not occur in the p27(KIPI) or epsilon-globin gene-related histones. The HDACi caused a marked decrease in HDAC1 and Myc and an increase in RNA polymerase II in proteins bound to the p21(WAF1) promoter. Thus, this study identifies effects of SAHA on p21(WAF1)-associated proteins that explain, at least in part, the selective effect of HDACi in altering gene expression.

Association of tobacco smoke exposure and respiratory syncitial virus infection with airways reactivity in early childhood

Exposure to infectious agents and environmental tobacco smoke are thought to induce bronchial hyperresponsiveness (BHR). This study was undertaken to determine the effects of passive exposure to tobacco smoke and respiratory syncitial virus (RSV) lower respiratory infection (LRI) during infancy on the occurrence of BHR in the first 2 years of life. Eighty-six cases of documented RSV (mean age, 188 days) and 78 controls (mean age, 162 days) were enrolled from the clinic and in-patient service of a single hospital. None had a history of prior LRI. Subjects were studied at 6-month intervals up to 19 months of age with a standardized respiratory illness and parental smoking questionnaire, partial expiratory flow-volume curves by the "hug" (rapid thoracic compression) technique, and methacholine challenge. Exposure to maternal and paternal cigarette smoking, maternal history of asthma, and mold exposure were associated with decreased levels of length-corrected maximal flow at functional residual capacity (V'(maxFRC)). RSV-LRI was not related to V'(maxFRC). After adjustment of V'(maxFRC) for these factors, V'(maxFRC) was a significantly and positively correlated with a methacholine concentration provoking a 40% fall in V'(maxFRC) (PC40) and negatively correlated with dose-response slope. After adjustment for V'(maxFRC), there were no independent effects of tobacco smoke exposure or RSV-LRI on methacholine responses. These data do not support a role for RSV as a risk factor for airways reactivity in childhood and indicate that exposure to tobacco smoke affects airways reactivity through its effects on airways.

Age dependence of human gastrocnemius Mg2+: fitting 31P-NMR spectra using quantum mechanics-based prior knowledge

The age dependence of human gastrocnemius Mg2+ concentration is demonstrated. To quantitate Mg2+ concentration, an original and accurate fitting algorithm using quantum mechanics-based prior knowledge is detailed. In a group of 28 volunteers (14 females) in the age range 5-80 years, pH, PCr/ATP and Pi/ATP values in the gastrocnemius were 7.02 +/- 0.02 pH, 4.16 +/- 0.33 and 0.13 +/- 0.02, respectively and independent of age and sex. By contrast, intracellular Mg2+ concentration (mM) decreased linearly (p < 0.05) with age (Mg2+ = 0.7803 +/- 0.0247-0.0027 +/- 0.0005 * age). No difference was found between sexes. From these results, it follows that care must be taken when comparing muscle Mg2+ data from subjects of different age. The hypothesis can be put forward that during aging insufficient intake and/or increased depletion of Mg2+ (e.g., intestinal hypoabsorption or urinary leakage) may affect the musculoskeletal system.

Assessment of ventricular function in critically ill patients: limitations of pulmonary artery catheterization. Institutions of the McSPI Research Group

OBJECTIVE

To determine the accuracy of conventional hemodynamic assessment using pulmonary artery catheter-derived data in critically ill patients.

DESIGN

Cohort study.

SETTING

Kaiser Permanente and Veterans Affairs Medical Centers.

PARTICIPANTS

Twenty-five consecutive patients who had undergone elective aortocoronary bypass surgery.

MEASUREMENTS AND MAIN RESULTS

In the intensive care unit, conventional assessment (CA) was performed hourly by clinicians using conventional (radial artery and pulmonary artery) hemodynamic measurements from which left ventricular (LV) function and intracardiac volume were estimated. Simultaneously, transesophageal echocardiography (TEE) data were recorded on videotape, blinded to the clinicians, and quantitatively analyzed off-line. TEE-determined LV function was classified as either normal (ejection fraction > or =40%) or abnormal (ejection fraction <40%) and intracardiac volume as normal (end-diastolic area = 8 to 22 cm2), low (end-diastolic area <8 cm2), or high (end-diastolic area >22 cm2).

CONCLUSION

Evaluable data included 130 of 150 (87%) observations of simultaneously collected CA and TEE data, averaging 5.6+/-4.4 observations per patient. The overall predictive probability for conventional clinical assessment of normal ventricular function was 98% (118/121), whereas for abnormal ventricular function it was 0% (0/9). For CA of volume, the overall predictive probabilities for hypovolemia, normovolemia, and hypervolemia were 50% (3/6), 60% (69/115), and 22% (2/9). Although conventional clinical assessment of normal LV function in the intensive care unit correlates well with echocardiographic assessment, both LV dysfunction and extremes of preload (hypovolemia or hypervolemia) are assessed poorly by clinicians using conventional clinical monitoring with pulmonary artery catheterization.

Cloning of the cDNA encoding phenylalanyl tRNA synthetase regulatory alpha-subunit-like protein whose expression is down-regulated during differentiation

Hybrid polar compounds (HPCs), such as suberoylanilide hydroxamic acid (SAHA), induce differentiation of transformed cells. Differential display of RNA was used to identify genes whose expression is changed during SAHA-induced differentiation of murine erythroleukemia (MEL) cells. One such cDNA was identified whose mRNA level decreased by 50% after 8h of SAHA treatment as determined by Northern blot analysis. The full-length cDNA (1944bp in length) was cloned by sequencing of an EST clone and rapid amplification of 5' cDNA ends (5'-RACE). The predicted amino acid sequence is 589 amino acids and shares 45% identity with the yeast cytoplasmic phenylalanyl tRNA synthetase (PheRS) regulatory alpha-subunit. Human EST clones which share over 90% identity of predicted amino acid sequence with this cDNA map to chromosome 2 near the paired box homeotic gene 3 (PAX3) locus, a region syngenic to mouse chromosome 1. This is the first report of the cloning of the full-length cDNA for the murine PheRS regulatory alpha-subunit-like protein. The level of PheRS alpha-subunit-like mRNA is regulated during differentiation but not during cell cycle progression.