Systematic review and meta-analysis of disease clustering in multimorbidity: a study protocol

INTRODUCTION

Multimorbidity is defined as the presence of two or more chronic diseases. Co-occurring diseases can have synergistic negative effects, and are associated with significant impacts on individual health outcomes and healthcare systems. However, the specific effects of diseases in combination will vary between different diseases. Identifying which diseases are most likely to co-occur in multimorbidity is an important step towards population health assessment and development of policies to prevent and manage multimorbidity more effectively and efficiently. The goal of this project is to conduct a systematic review and meta-analysis of studies of disease clustering in multimorbidity, in order to identify multimorbid disease clusters and test their stability.

METHODS AND ANALYSIS

We will review data from studies of multimorbidity that have used data clustering methodologies to reveal patterns of disease co-occurrence. We propose a network-based meta-analytic approach to perform meta-clustering on a select list of chronic diseases that are identified as priorities for multimorbidity research. We will assess the stability of obtained disease clusters across the research literature to date, in order to evaluate the strength of evidence for specific disease patterns in multimorbidity.

ETHICS AND DISSEMINATION

This study does not require ethics approval as the work is based on published research studies. The study findings will be published in a peer-reviewed journal and disseminated through conference presentations and meetings with knowledge users in health systems and public health spheres.

PROSPERO REGISTRATION NUMBER

CRD42023411249.

Microbiome-scale analysis of aerosol facemask contamination during nebulization therapy in hospital

BACKGROUND

Microbial contamination of aerosol facemasks could be a source of nosocomial infections during nebulization therapy in hospital, prompting efforts to identify these contaminants. Identification of micro-organisms in medical devices has traditionally relied on culture-dependent methods, which are incapable of detecting the majority of these microbial contaminants. This challenge could be overcome with culture-independent sequencing-based techniques that are suited for the profiling of complex microbiomes.

AIM

To characterize the microbial contaminants in aerosol facemasks used for nebulization therapy, and identify factors influencing the composition of these microbial contaminants with the acquisition and analysis of comprehensive microbiome-scale profiles using culture-independent high-throughput sequencing.

METHODS

Used aerosol facemasks collected from hospitalized patients were analysed with culture-independent 16S rRNA gene-based amplicon sequencing to acquire microbiome-scale comprehensive profiles of the microbial contaminants. Microbiome-based analysis was performed to identify potential sources of microbial contamination in facemasks.

FINDINGS

Culture-independent high-throughput sequencing was demonstrated for the capacity to acquire microbiome-scale profiles of microbial contaminants on aerosol facemasks. Microbial source identification enabled by the microbiome-scale profiles linked microbial contamination on aerosol facemasks to the human skin and oral microbiota. Antibiotic treatment with levofloxacin was found to reduce contamination of the facemasks by oral microbiota.

CONCLUSION

Sequencing-based microbiome-scale analysis is capable of providing comprehensive characterization of microbial contamination in aerosol facemasks. Insight gained from microbiome-scale analysis facilitates the development of effective strategies for the prevention and mitigation of the risk of nosocomial infections arising from exposure to microbial contamination of aerosol facemasks, such as targeted elimination of potential sources of contamination.

Prescription of hormone replacement therapy among cervical cancer patients with treatment-induced premature menopause

OBJECTIVE

To examine the utilization of hormone replacement therapy (HRT) among newly diagnosed cervical cancer patients who experienced premature menopause due to primary treatment.

METHODS

The MarketScan Databases were used to identify newly diagnosed cervical cancer patients <50 years of age with premature menopause after hysterectomy with bilateral salpingo-oophorectomy (primary surgery) or primary external beam pelvic radiation (primary radiotherapy). We examined the cumulative utilization of HRT until 24 months after the loss of ovarian function. Fine-Gray subdistribution hazard models were developed to examine the factors associated with cumulative HRT use. The duration of HRT use was analyzed by Kaplan-Meier curves.

RESULTS

A total of 1826 patients, including 352 (19.3%) who underwent primary surgery and 1474 (80.7%) who received primary radiotherapy, were identified. Overall, 39.0% of patients received HRT within 24 months of primary treatment. HRT was used in 49.4% of those who underwent primary surgery and in 36.6% of those who received primary radiotherapy (p<0.0001). The median duration of HRT use was 60 days among the entire cohort and was significantly shorter for the primary radiotherapy group than the primary surgery group (35 vs 90 days, p<0.0001). Primary radiotherapy, older age, residency in the Northeastern USA, and Black race were associated with a lower likelihood of HRT use.

CONCLUSIONS

HRT was prescribed to less than half of patients with newly diagnosed cervical cancer under the age of 50 who experienced premature menopause due to primary treatment. Among those who used HRT the duration of use was short.

Multimorbidity resilience and health behaviors among older adults: A longitudinal study using the Canadian Longitudinal Study on Aging

Objective

There has been a growing interest in examining why some individuals adapt and bounce back from multimorbidity (resilience) better than others. This paper investigates the positive role of protective health behaviors on multimorbidity resilience (MR) among older adults focusing on older persons with two or more concurrent chronic conditions, and separately for three multimorbidity chronic illness clusters.

Methods

Using Baseline and Follow-up One data from the Comprehensive Cohort of the Canadian Longitudinal Study on Aging, we studied 10,628 participants aged 65 years and older who reported two or more of 27 chronic conditions, and three multimorbidity clusters: Cardiovascular/metabolic, Musculoskeletal, and Mental health. Associations between health behaviors and MR were evaluated using Linear Mixed Models, adjusting for socio-demographic, social/environmental, and illness context social determinants of health.

Results

Among older adults with two or more illnesses, smoking, satisfaction with sleep, appetite, and skipping meals were associated with MR in the expected direction. Also, obesity (compared to normal weight) and skipping meals showed longitudinal interaction effects with survey wave. Most of the results were replicated for the physical multimorbidity clusters (Cardiovascular/metabolic and Musculoskeletal) compared to the full 2+ multimorbidity analyses; however, for the Mental health cluster, only satisfaction with sleep was supported as a lifestyle predictor of MR.

Discussion

Several modifiable health behaviors identified in the broader health and aging literature are important in affecting levels of multimorbidity resilience in older age. These factors are important strength-based areas to target. Additionally, several social determinants of health are also supported and parallel research on multimorbidity risk. The effects of lifestyle factors for resilience among older adults is dependent on the type of multimorbidity measured. We conclude that the results have significant public health, program intervention, and clinical implications for healthy aging among persons coping with multimorbidity.

Exploring biomarkers of processing speed and executive function: The role of the anterior thalamic radiations

INTRODUCTION

Processing speed and executive function are often impaired after stroke and in typical aging. However, there are no reliable neurological markers of these cognitive impairments. The trail making test (TMT) is a common index of processing speed and executive function. Here, we tested candidate MRI markers of TMT performance in a cohort of older adults and individuals with chronic stroke.

METHODS

In 61 older adults and 32 individuals with chronic stroke, we indexed white matter structure with region-specific lesion load (of white matter hyperintensities (WMHs) and stroke lesions) and diffusion tensor imaging (DTI) from four regions related to TMT performance: the anterior thalamic radiations (ATR), superior longitudinal fasciculus (SLF), forceps minor, and cholinergic pathways. Regression modelling was used to identify the marker(s) that explained the most variance in TMT performance.

RESULTS

DTI metrics of the ATR related to processing speed in both the older adult (TMT A: β = -3.431, p < 0.001) and chronic stroke (TMT A: β = 11.282, p < 0.001) groups. In the chronic stroke group executive function was best predicted by a combination of ATR and forceps minor DTI metrics (TMT B: _adjustedR² = 0.438, p < 0.001); no significant predictors of executive function (TMT B) emerged in the older adult group. No imaging metrics related to set shifting (TMT B-A). Regional DTI metrics predicted TMT performance above and beyond whole-brain stroke and WMH volumes and removing whole-brain lesion volumes improved model fits.

CONCLUSIONS

In this comprehensive assessment of candidate imaging markers, we demonstrate an association between ATR microstructure and processing speed and executive function performance. Regional DTI metrics provided better predictors of cognitive performance than whole-brain lesion volumes or regional lesion load, emphasizing the importance of lesion location in understanding cognition. We propose ATR DTI metrics as novel candidate imaging biomarker of post-stroke cognitive impairment.

Microbiome Profiles of Nebulizers in Hospital Use

Background: Nebulizers are used to provide treatment to respiratory patients. Concerns over nosocomial infection risks from contaminated nebulizers raise the critical need to identify all microbial populations in nebulizers used by patients. However, conventional culture-dependent techniques are inadequate with the ability to identify specific microbial populations only. Therefore, the aims of this study were to acquire complete profiles of microbiomes in nebulizers used by in-patients with culture-independent high-throughput sequencing and identify sources of microbial contaminants for the development of effective practices to reduce microbial contamination in nebulizer devices. Methods: This study was conducted at the University of Tennessee Medical Center in Knoxville, TN. Nebulizers were collected between May 2018 and October 2018 from inpatients admitted to the floors for pneumonia or chronic obstructive pulmonary disease exacerbations. Nebulizers were sampled for 16S rRNA gene-based amplicon sequencing to profile nebulizer microbiomes and perform phylogenetic analysis. A Bayesian community-wide culture-independent microbial source tracking technique was used to quantify the contribution of human-associated microbiota as potential sources of nebulizer contamination. Results: Culture-independent sequencing detected diverse microbial populations in nebulizers, represented by 18 abundant genera. Stenotrophomonas was identified as the most abundant genus, accounting for 12.4% of the nebulizer microbiome, followed by Rhizobium, Staphylococcus, Streptococcus, and Ralstonia. Phylogenetic analysis revealed the presence of multiple phylotypes with close relationship to potential pathogens. Contributing up to 15% to nebulizer microbiomes, human-associated microbiota was not identified as the primary sources of nebulizer contamination. Conclusion: Culture-independent sequencing was demonstrated to be capable of acquiring comprehensive profiles of microbiomes in nebulizers used by in-patients. Phylogenetic analysis identified differences in pathogenicity between closely related phylotypes. Microbiome profile-enabled community-wide culture-independent microbial source tracking suggested greater importance of environmental sources than human sources as contributors to nebulizer microbiomes, providing important insight for the development of effective strategies for the monitoring and control of nebulizer devices to mitigate infection risks in the hospital.

Pevonedistat (MLN4924): mechanism of cell death induction and therapeutic potential in colorectal cancer

Pevonedistat (MLN4924), a selective inhibitor of the NEDD8-activating enzyme E1 regulatory subunit (NAE1), has demonstrated significant therapeutic potential in several malignancies. Although multiple mechanisms-of-action have been identified, how MLN4924 induces cell death and its potential as a combinatorial agent with standard-of-care (SoC) chemotherapy in colorectal cancer (CRC) remains largely undefined. In an effort to understand MLN4924-induced cell death in CRC, we identified p53 as an important mediator of the apoptotic response to MLN4924. We also identified roles for the extrinsic (TRAIL-R2/caspase-8) and intrinsic (BAX/BAK) apoptotic pathways in mediating the apoptotic effects of MLN4924 in CRC cells, as well as a role for BID, which modulates a cross-talk between these pathways. Depletion of the anti-apoptotic protein FLIP, which we identify as a novel mediator of resistance to MLN4924, enhanced apoptosis in a p53-, TRAIL-R2/DR5-, and caspase-8-dependent manner. Notably, TRAIL-R2 was involved in potentiating the apoptotic response to MLN4924 in the absence of FLIP, in a ligand-independent manner. Moreoever, when paired with SoC chemotherapies, MLN4924 demonstrated synergy with the irinotecan metabolite SN38. The cell death induced by MLN4924/SN38 combination was dependent on activation of mitochondria through BAX/BAK, but in a p53-independent manner, an important observation given the high frequency of TP53 mutation(s) in advanced CRC. These results uncover mechanisms of cell death induced by MLN4924 and suggest that this second-generation proteostasis-disrupting agent may have its most widespread activity in CRC, in combination with irinotecan-containing treatment regimens.

The SCFSkp2 ubiquitin ligase complex modulates TRAIL-R2-induced apoptosis by regulating FLIP(L)

TRAIL-R2 (DR5) is a clinically-relevant therapeutic target and a key target for immune effector cells. Herein, we identify a novel interaction between TRAIL-R2 and the Skp1-Cullin-1-F-box (SCF) Cullin-Ring E3 Ubiquitin Ligase complex containing Skp2 (SCF^Skp2). We find that SCF^Skp2 can interact with both TRAIL-R2’s pre-ligand association complex (PLAC) and ligand-activated death-inducing signalling complex (DISC). Moreover, Cullin-1 interacts with TRAIL-R2 in its active NEDDylated form. Inhibiting Cullin-1’s DISC recruitment using the NEDDylation inhibitor MLN4924 (Pevonedistat) or siRNA increased apoptosis induction in response to TRAIL. This correlated with enhanced levels of the caspase-8 regulator FLIP at the TRAIL-R2 DISC, particularly the long splice form, FLIP(L). We subsequently found that FLIP(L) (but not FLIP(S), caspase-8, nor the other core DISC component FADD) interacts with Cullin-1 and Skp2. Importantly, this interaction is enhanced when FLIP(L) is in its DISC-associated, C-terminally truncated p43-form. Prevention of FLIP(L) processing to its p43-form stabilises the protein, suggesting that by enhancing its interaction with SCF^Skp2, cleavage to the p43-form is a critical step in FLIP(L) turnover. In support of this, we found that silencing any of the components of the SCF^Skp2 complex inhibits FLIP ubiquitination, while overexpressing Cullin-1/Skp2 enhances its ubiquitination in a NEDDylation-dependent manner. DISC recruitment of TRAF2, previously identified as an E3 ligase for caspase-8 at the DISC, was also enhanced when Cullin-1’s recruitment was inhibited, although its interaction with Cullin-1 was found to be mediated indirectly via FLIP(L). Notably, the interaction of p43-FLIP(L) with Cullin-1 disrupts its ability to interact with FADD, caspase-8 and TRAF2. Collectively, our results suggest that processing of FLIP(L) to p43-FLIP(L) at the TRAIL-R2 DISC enhances its interaction with co-localised SCF^Skp2, leading to disruption of p43-FLIP(L)’s interactions with other DISC components and promoting its ubiquitination and degradation, thereby modulating TRAIL-R2-mediated apoptosis.

Defining the molecular evolution of extrauterine high grade serous carcinoma

OBJECTIVE

High grade serous carcinoma (HGSC) is the most common and most aggressive, subtype of epithelial ovarian cancer. It presents as advanced stage disease with poor prognosis. Recent pathological evidence strongly suggests HGSC arises from the fallopian tube via the precursor lesion; serous tubal intraepithelial carcinoma (STIC). However, further definition of the molecular evolution of HGSC has major implications for both clinical management and research. This study aims to more clearly define the molecular pathogenesis of HGSC.

METHODS

Six cases of HGSC were identified at the Northern Ireland Gynaecological Cancer Centre (NIGCC) that each contained ovarian HGSC (HGSC), omental HGSC (OMT), STIC, normal fallopian tube epithelium (FTE) and normal ovarian surface epithelium (OSE). The relevant formalin-fixed paraffin embedded (FFPE) tissue samples were retrieved from the pathology archive via the Northern Ireland Biobank following attaining ethical approval (NIB11:005). Full microarray-based gene expression profiling was performed on the cohort. The resulting data was analysed bioinformatically and the results were validated in a HGSC-specific in-vitro model.

RESULTS

The carcinogenesis of HGSC was investigated and showed the molecular profile of HGSC to be more closely related to normal FTE than OSE. STIC lesions also clustered closely with HGSC, indicating a common molecular origin.

CONCLUSION

This study provides strong evidence suggesting that extrauterine HGSC arises from the fimbria of the distal fallopian tube. Furthermore, several potential pathways were identified which could be targeted by novel therapies for HGSC. These findings have significant translational relevance for both primary prevention and clinical management of the disease.

Finding the fifth intercostal space for chest drain insertion: guidelines and ultrasound

OBJECTIVES

International guidelines exist for chest drain insertion and recommend identifying the fifth intercostal space or above, around the midaxillary line. In a recent study, applying these guidelines in cadavers risked insertion in the 6th intercostal space or below in 80% of cases. However, there are limitations of cadaveric studies and this investigation uses ultrasound to determine the intercostal space identified when applying these guidelines in healthy adult volunteers.

METHODS

On each side of the chest wall in 31 volunteers, the position for drain insertion was identified using the European Trauma Course method, Advanced Trauma Life Support (ATLS) method, British Thoracic Society's 'safe triangle' and the 'traditional' method of palpation. Ultrasound imaging was used to determine the relationship of the skin marks with the underlying intercostal spaces.

RESULTS

Five methods were assessed on 60 sides. In contrast to the cadaveric study, 94% of skin marks lay over a safe intercostal space. However, the range of intercostal spaces found spanned the second to the seventh space. In 44% of women, the inferior boundary of the 'safe triangle' and the ATLS guidelines located the sixth intercostal space or below.

CONCLUSIONS

Current guidelines often identify a safe site for chest drain insertion, although the same site is not reproducibly found. In addition, women appear to be at risk of subdiaphragmatic drain insertion when the nipple is used to identify the fifth intercostal space. Real-time ultrasonography can be used to confirm the intercostal space during this procedure, although a safe guideline is still needed for circumstances in which ultrasound is not possible.

Changes in thresholds for intracortical excitability in chronic stroke: more than just altered intracortical inhibition

PURPOSE

The purpose of the present study was to assess changes in thresholds for the onset of short intracortical inhibition (SICI) and intracortical facilitation (ICF) in individuals with chronic stroke compared to age-matched healthy adults and evaluate the relationship between these thresholds and motor function in the chronic stroke group.

METHODS

Paired-pulse transcranial magnetic stimulation was used to derive thresholds for the onset of SICI and ICF in 12 neurologically healthy and 12 individuals with chronic stroke. Motor evoked potentials were elicited by a test stimulus of fixed intensity preceded by a conditioning stimulus ranging from 0%-125% of active motor threshold to generate recruitment curves. Regression functions were fit to these recruitment curves to identify thresholds for the onset of SICI and ICF. Mixed measures analysis of variance was used to compare thresholds for each hemisphere within and between groups.

RESULTS

Results showed a significant three-way interaction between Group (stroke, healthy), Hemisphere (ipsilesional, contralesional) and Stimulus interval (2 ms, 12 ms). Significant differences in the thresholds for the onset of both SICI and ICF were present in individuals with chronic stroke, with no between hemisphere differences for the control group. When compared to age-matched controls, comparisons revealed significant reductions in ipsilesional, but not contralesional thresholds for the onset of ICF, and significant reductions in contralesional, but not ipsilesional, thresholds for the onset of SICI in individuals with chronic stroke. In addition, as thresholds for ICF and SICI in stroke patients approached the level of healthy adults, higher function on the Wolf Motor Function Test was observed.

CONCLUSIONS

Reduced thresholds for the onset of SICI and ICF observed in the present study indicate that both inhibitory and facilitatory systems mediate changes in cortical excitability in chronic stroke patients. The association between higher onset thresholds and motor function in the stroke group also suggests that these thresholds have potential utility for tracking functional motor improvements in patients with chronic stroke. This study provides new insights to further characterize changes in intracortical neurotransmission that play an important role in modulating neuroplasticity and the potential relationship between inhibitory and facilitatory networks and motor function post-stroke.

Impact of introducing practical obstetric multi-professional training (PROMPT) into maternity units in Victoria, Australia

OBJECTIVE

To assess the introduction of Practical Obstetric Multi-professional Training (PROMPT) into maternity units and evaluate effects on organisational culture and perinatal outcomes.

DESIGN

A retrospective cohort study.

SETTING

Maternity units in eight public hospitals in metropolitan and regional Victoria, Australia.

POPULATION

Staff in eight maternity units and a total of 43,408 babies born between July 2008 and December 2011.

METHODS

Representatives from eight Victorian hospitals underwent a single day of training (Train the Trainer), to conduct PROMPT. Organisational culture was compared before and after PROMPT. Clinical outcomes were evaluated before, during and after PROMPT.

MAIN OUTCOME MEASURES

The number of courses run and the proportion of staff trained were determined. Organisational culture was measured using the Safety Attitude Questionnaire. Clinical measures included Apgar scores at 1 and 5 minutes (Apgar 1 and Apgar 5), cord lactate, blood loss and length of baby's stay in hospital.

RESULTS

Seven of the eight hospitals conducted PROMPT. Overall about 50% of staff were trained in each year of the study. Significant increases were found in Safety Attitude Questionnaire scores representing domains of teamwork (Hedges' g 0.27, 95% confidence interval [95% CI] 0.13-0.41), safety (Hedges' g 0.28, 95% CI 0.15-0.42) and perception of management (Hedges' g 0.17, 95% CI 0.04-0.31). There were significant improvements in Apgar 1 (OR 0.84, 95% CI 0.77-0.91), cord lactates (odds ratio 0.92, 95% CI 0.85-0.99) and average length of baby's stay in hospital (Hedges' g 0.03, 95% CI 0.01-0.05) during or after training, but no change in Apgar 5 scores or proportion of cases with high blood loss.

CONCLUSION

PROMPT can be introduced using the Train the Trainer model. Improvements in organisational culture and some clinical measures were observed following PROMPT.

Transgenic expression of interferon-γ in mouse stomach leads to inflammation, metaplasia, and dysplasia

Gastric adenocarcinoma is one of the leading causes of cancer mortality worldwide. It arises through a stepwise process that includes prominent inflammation with expression of interferon-γ (IFN-γ) and multiple other pro-inflammatory cytokines. We engineered mice expressing IFN-γ under the control of the stomach-specific H(+)/K(+) ATPase β promoter to test the potential role of this cytokine in gastric tumorigenesis. Stomachs of H/K-IFN-γ transgenic mice exhibited inflammation, expansion of myofibroblasts, loss of parietal and chief cells, spasmolytic polypeptide expressing metaplasia, and dysplasia. Proliferation was elevated in undifferentiated and metaplastic epithelial cells in H/K-IFN-γ transgenic mice, and there was increased apoptosis. H/K-IFN-γ mice had elevated levels of mRNA for IFN-γ target genes and the pro-inflammatory cytokines IL-6, IL-1β, and tumor necrosis factor-α. Intracellular mediators of IFN-γ and IL-6 signaling, pSTAT1 and pSTAT3, respectively, were detected in multiple cell types within stomach. H/K-IFN-γ mice developed dysplasia as early as 3 months of age, and 4 of 39 mice over 1 year of age developed antral polyps or tumors, including one adenoma and one adenocarcinoma, which expressed high levels of nuclear β-catenin. Our data identified IFN-γ as a pivotal secreted factor that orchestrates complex changes in inflammatory, epithelial, and mesenchymal cell populations to drive pre-neoplastic progression in stomach; however, additional alterations appear to be required for malignant conversion.

Basal cell carcinomas in mice arise from hair follicle stem cells and multiple epithelial progenitor populations

Uncontrolled Hedgehog (Hh) signaling leads to the development of basal cell carcinoma (BCC), the most common human cancer, but the cell of origin for BCC is unclear. While Hh pathway dysregulation is common to essentially all BCCs, there exist multiple histological subtypes, including superficial and nodular variants, raising the possibility that morphologically distinct BCCs may arise from different cellular compartments in skin. Here we have shown that induction of a major mediator of Hh signaling, GLI2 activator (GLI2ΔN), selectively in stem cells of resting hair follicles in mice, induced nodular BCC development from a small subset of cells in the lower bulge and secondary hair germ compartments. Tumorigenesis was markedly accelerated when GLI2ΔN was induced in growing hair follicles. In contrast, induction of GLI2ΔN in epidermis led to the formation of superficial BCCs. Expression of GLI2ΔN at reduced levels in mice yielded lesions resembling basaloid follicular hamartomas, which have previously been linked to low-level Hh signaling in both mice and humans. Our data show that the cell of origin, tissue context (quiescent versus growing hair follicles), and level of oncogenic signaling can determine the phenotype of Hh/Gli-driven skin tumors, with high-level signaling required for development of superficial BCC-like tumors from interfollicular epidermis and nodular BCC-like tumors from hair follicle stem cells.

Prenatal Tobacco Smoke Exposure and Genomewide Methylation in Adulthood

Genomic DNA demethylation, including demethylation of repetitive elements (which comprise 45% of the human genome), has been linked to increased risk of breast and other cancers. Genomic DNA methylation can be altered prenatally and throughout life and may be a mechanism through which the environment alters disease risk. There is evidence that prenatal tobacco smoke exposure has a persistent impact on genomic DNA methylation; however, no study to date has assessed the association between prenatal smoke exposure and adult repetitive element methylation. We measured repetitive element methylation of Alu, LINE-1, and Sat2 using MethyLight in 92 members of the New York Women's Birth Cohort, a follow-up of former female participants of the New York site of the U.S. National Collaborative Perinatal Project (mean age at blood draw = 43.5, SD = 1.8). Prenatal smoke exposure was reported prospectively. We estimated associations using multivariable linear regression, and used the natural log of Alu, LINE-1, and Sat2 methylation level. Thirty-one (36%) participants were exposed to prenatal smoke. These participants were more likely to smoke at the time of interview (P &lt; 0.01). Prenatal smoke exposure was inversely associated with genomic DNA methylation of Sat2 and Alu, adjusted for age, childhood environmental tobacco smoke exposure (ETS) and adult smoking status (exposed vs. unexposed to prenatal smoke: Sat2: β = −0.20, 95% CI = −0.39, −0.02; Alu: β = −0.09, 95% CI = −0.26, 0.08). In multivariable models, childhood ETS had a positive, borderline significant association with Sat2 methylation (β = 0.17, 95% CI −0.02, 0.37). If replicated in larger studies, these results suggest that prenatal smoke exposure may have a persistent impact on genomic DNA demethylation of Sat2 and Alu in adulthood, and thus may be a pathway through which prenatal smoke exposure impacts adult disease. Results are strengthened by the fact that prenatal smoke exposure data were collected prospectively in the early 1960s, before there was a stigma associated with maternal smoking during pregnancy. These results are consistent with the one study assessing this relation in children. Further studies are needed to confirm this finding and to investigate the underlying biological mechanism.

Are sexual problems more common in women who have had a tubal ligation? A population-based study of Australian women

OBJECTIVE

To investigate whether women who have had a tubal ligation are more likely to experience sexual problems than other women.

DESIGN

Population-based telephone survey.

SETTING

Australia-wide, including cities, regional towns, and rural areas.

POPULATION

A total of 3448 Australian women aged between 16 and 64 years.

METHODS

Women were surveyed using random-digit dialling throughout 2004 and 2005.

MAIN OUTCOME MEASURES

Prevalence of sexual problems and ratings of sexual satisfaction, relationship satisfaction, and sexual pleasure.

RESULTS

From a weighted sample of 2721 women, 447 (16.4%) reported having had a tubal ligation, with 85.0% currently aged between 40 and 64 years. Having a tubal ligation was not associated with any specific sexual problem, such as physical pain during sex or an inability to reach orgasm. In fact, after controlling for age and other sociodemographic differences, sterilised women were significantly less likely than non-sterilised women to lack an interest in having sex (OR 0.69, 95% CI 0.54-0.89), to take 'too long' to reach orgasm (OR 0.69, 95% CI 0.50-0.96), to experience vaginal dryness during sex (OR 0.70, 95% CI 0.50-0.96), and to find sex unpleasurable (OR 0.64, 95% CI 0.46-0.90). Sterilised women were also more likely to experience extremely high levels of sexual satisfaction (OR 1.66, 95% CI 1.27-2.18), relationship satisfaction (OR 1.29, 95% CI 1.01-1.67), and sexual pleasure (OR 1.59, 95% CI 1.20-2.12).

CONCLUSIONS

Our findings suggest no adverse effects, and possibly some benefits, for the sexual lives of women undergoing tubal ligation. These findings should be included with other educational material for couples considering sterilisation as a contraception option.

Helicon plasma generator-assisted surface conversion ion source for the production of H(-) ion beams at the Los Alamos Neutron Science Center

The converter-type negative ion source currently employed at the Los Alamos Neutron Science Center (LANSCE) is based on cesium enhanced surface production of H(-) ion beams in a filament-driven discharge. In this kind of an ion source the extracted H(-) beam current is limited by the achievable plasma density which depends primarily on the electron emission current from the filaments. The emission current can be increased by increasing the filament temperature but, unfortunately, this leads not only to shorter filament lifetime but also to an increase in metal evaporation from the filament, which deposits on the H(-) converter surface and degrades its performance. Therefore, we have started an ion source development project focused on replacing these thermionic cathodes (filaments) of the converter source by a helicon plasma generator capable of producing high-density hydrogen plasmas with low electron energy. In our studies which have so far shown that the plasma density of the surface conversion source can be increased significantly by exciting a helicon wave in the plasma, and we expect to improve the performance of the surface converter H(-) ion source in terms of beam brightness and time between services. The design of this new source and preliminary results are presented, along with a discussion of physical processes relevant for H(-) ion beam production with this novel design. Ultimately, we perceive this approach as an interim step towards our long-term goal, combining a helicon plasma generator with an SNS-type main discharge chamber, which will allow us to individually optimize the plasma properties of the plasma cathode (helicon) and H(-) production (main discharge) in order to further improve the brightness of extracted H(-) ion beams.

Flavor preferences conditioned by postingestive effects of nutrients in preweanling rats

The purpose of these experiments was to determine if preweanling rats, like adults, are capable of learning to associate an arbitrary flavor with the postingestive effects of nutrients, and then demonstrate a preference for that flavor after weaning. In Experiment 1, preweanlings were trained daily from postnatal day (P) 16 through P19 with intraoral (IO) infusions of a grape or cherry flavor (CS+) mixed with 20% glucose (US), and the opposite flavor (CS-) mixed with 0.05% saccharin. After weaning, rats were given a 4-h two-bottle choice between the CS+ and CS- flavors both presented in 0.05% saccharin. Rats preferred the flavor previously paired with glucose. In Experiment 2 using similar methods, rats learned to prefer a flavor (CS+G) paired with a glucose US over a flavor (CS+S) paired with a sweeter but less nutritive sucrose US, indicating involvement of postingestive reinforcement. In Experiment 3 preweanling rats with IO and intragastric (IG) catheters were trained with a CS+ flavor paired with IG nutrient infusion, and a CS- flavor paired with no IG infusion. These rats showed no flavor preference 3 days after weaning, but did significantly prefer the CS+ flavor over the CS- flavor 10 days after weaning. Together these experiments demonstrate that neural mechanisms for flavor-nutrient associations are developed before weaning, allowing young rats to learn associations between arbitrary flavors and nutritive consequences. Thus nutrient conditioning may be one way that early experience (such as flavors from the maternal diet transmitted in milk) influences later dietary preferences.

Characterization of the G91del CRYBA1/3-crystallin protein: a cause of human inherited cataract

Congenital cataract is a leading cause of visual disability in children. Inherited isolated (non-syndromic) cataract represents a significant proportion of cases and the identification of genes responsible for inherited cataract will lead to a better understanding of the mechanism of cataract formation at the molecular level both in congenital and age-related cataract. Crystallins are abundantly expressed in the developing human lens and represent excellent candidate genes for inherited cataract. A genome-wide search of a five-generation family with autosomal dominant lamellar cataract demonstrated linkage to the 17p12-q11 region. Screening of the CRYBA1/3 gene showed a 3 bp deletion, which resulted in a G91del mutation within the tyrosine corner, that co-segregated with disease and was not found in 96 normal controls. In order to understand the molecular basis of cataract formation, the mutant protein was expressed in vitro and its unfolding and refolding characteristics assessed using far-UV circular dichroism spectroscopy. Defective folding and a reduction in solubility were found. As the wild-type protein did not refold into the native conformation following unfolding, a corresponding CRYBB2 mutant was genetically engineered and its refolding characteristics analysed and compared with wild-type CRYBB2. Its biophysical properties support the hypothesis that removal of the glycine residue from the tyrosine corner impairs the folding and solubility of beta-crystallin proteins. This study represents the first comprehensive description of the biophysical consequences of a mutant beta-crystallin protein that is associated with human inherited cataract.

[Chemistry of alpha-aminonitriles. Aziridine-2-carbonitrile: photochemical formation from 2-aminopropenenitrile]

2-Aminopropenenitrile in solvents such as MeCN, MeOH, or H2O is photoisomerized by UV light to racemic aziridine-2-carbonitrile (rac-2); the larger part of the starting material, however, fragments to HCN and MeCN. The observed photocyclization constitutes a structural connection within an ensemble of C3H4N2 compounds considered to be potentially relevant to prebiotic chemistry.

Gender differences in alcohol consumption and adverse drinking consequences: cross-cultural patterns

AIMS

To examine the consistency and/or variability of gender differences in drinking behavior cross-culturally.

DESIGN, SETTING, PARTICIPANTS

Women's and men's responses in 16 general population surveys from 10 countries, analyzed by members of the International Research Group on Gender and Alcohol.

MEASUREMENTS

Comparable measures of drinking, versus abstention, typical drinking frequencies and quantities, heavy episodic drinking, intoxication, morning drinking, and alcohol-related family and occupational problems.

FINDINGS

Women and men differed little in the probability of currently drinking versus abstaining, but men consistently exceeded women in typical drinking frequencies and quantities and in rates of heavy drinking episodes and adverse drinking consequences, while women were consistently more likely than men to be life-time abstainers. In older age groups, both men and women drank smaller quantities of alcohol and were more likely to stop drinking altogether, but drinking frequencies did not change consistently with age.

CONCLUSIONS

A theoretical synthesis proposes that gender roles may amplify biological differences in reactions to alcohol, and that gender differences in drinking behavior may be modified by macrosocial factors that modify gender role contrasts.

Management of blunt splenic trauma: significant differences between adults and children

BACKGROUND

Although highly successful in children, nonoperative management of blunt splenic injury in adults is less defined. The purpose of this study was to determine whether mechanism of injury, grade of splenic injury, associated injuries, and pattern of injury differ between adults and children (younger than 15 years of age).

METHODS

Four hundred eleven patients (293 adults and 118 pediatric patients) with blunt splenic injury were admitted to an affiliated adult/pediatric trauma program from 1989 to 1994. Computed tomography (CT) scans were interpreted in a blinded fashion. Mechanism of injury was significantly different for adults versus children (p < 0.05): motor vehicle crash (66.9% versus 23.7%), motorcycle (8.8% versus 0.8%), sports (2.4% versus 16.9%), falls (8.8% versus 25.4%), pedestrian/automobile (4.4% versus 11.0%), bicycle (1.4% versus 9.3%), and other (7.3% versus 12.7%).

RESULTS

Higher injury severity scores, lower Glasgow Coma Scales, and higher mortality indicated that the adults were more severely injured than the children. Fifty-nine percent of the adults and 7% of the children required immediate laparotomy for splenic injury. Both CT grade and quantity of blood on CT predicted the need for exploration in adults but not in children. An injury severity score above 15 and high-energy mechanisms correlated with the need for operative intervention.

CONCLUSIONS

Rather than children simply being physically different, they are injured differently than adults, hence the high rate of nonoperative management.

Determinants of suggestions for alcohol treatment

Entry to treatment is often precipitated by suggestions or pressure from relatives or friends, but we know little of the circumstances in which suggestions to cut down on drinking include advice to seek professional help. In 1993, 1034 Ontario adults were asked in a random digit dialling telephone survey if they had said something to a friend or relative about their drinking, or suggested they cut down. About 35% had said something within the last year, and 15% had taken the further step of suggesting they seek professional help or helping them get assistance. Respondents were asked a series of questions about the circumstances of the most recent time they had said something to the person. Whether respondents who said something recommended seeking professional help is related to these circumstances, and to the respondent's demographics and relationship to the drinker.

Alcohol, drugs and gambling in the Ontario adult population, 1994

OBJECTIVE

To demonstrate the link between gambling, alcohol and drug problems among Ontario adults and to present information on the relationship between expenditures on gambling and type of gambling with gambling problems.

METHOD

Using data collected in a 1994 telephone survey of 2,016 randomly chosen Ontario adults, gambling problems are related to the CAGE scale of alcohol problems and the ICD-10 measure of alcohol dependence, as well as smoking, other drug use, and demographic variables. Descriptive tables based on crosstabulations and means are provided, as well as a series of 9 logistic regression models.

RESULTS

The most significant predictor of gambling problems was the amount spent on gambling in the preceding 30 days, with alcohol dependence on the ICD-10 scale and age also important predictors. Lottery players, compared to other gamblers, are more likely to be male, relatively less affluent, older on average, more likely to report alcohol problems (but not dependence) and be currently smoking.

CONCLUSIONS

The results make clear that heavy drinking and drinking problems are associated with higher levels of spending on gambling and reports of gambling problems. This leads to the suggestion that treatment programs for those with gambling, alcohol or other drug problems should assess that possibility of comorbidity, since the presence of more than one of these problems can significantly affect the success of treatment and contribute to relapse.

Natural outcomes of stage 1, 2, 3, and 4 idiopathic macular holes

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The risk of harm to oneself from drinking, Canada 1989

In a national sample of 11,634 Canadians aged 15 years and above, risk curves for harm to six life-areas from one's own drinking and for assault by another drinker rose steadily with the respondent's volume of alcohol consumption. While drinking five or more drinks on an occasion at least once a month substantially raised the risk at a given volume of drinking, the risk rose with volume even among those not regularly drinking five or more drinks. These relationships remained in logistic regressions which controlled for gender, age and educational level. Younger respondents, those without higher education and men reported more harm for a given level of their own drinking although differences by gender disappeared above one-third of one drink per day. Three sets of guidelines for low-risk drinking--two from Canada, and one generally used in Britain--were compared in terms of the proportions of respondents reporting harm from their own drinking among those who had kept within the guideline in the previous 7 days' drinking. More restrictiveness in the guidelines was associated with substantial reductions in reported drinking-related harm.

[Substitution of ascorbic acid for potassium bromide in the making of French bread]

The potassium bromate (PB) is the flour improving additive for bread making, most widely used in Venezuela. This additive has been reported to have hazardous effects. For this reason it has been forbidden in various countries. In order to find a substitute for PB, the feasibility of using ascorbic acid (AA) in bread making flours was considered. Flours with 80, 40 and 20 ppm of AA were tested and contrasted with an experimental and industrial flour with 80 ppm of PB, maximum quantity allowed by the Venezuelan Legislation. The effect of these additives was evaluated on French bread, of high consumption in our country. It was found that the bread prepared using the flour containing 20 ppm of AA did not present significant differences from those made out of the pattern flour, concerning their organoleptic and physico-chemical properties. It was demonstrated that it is technically feasible to replaced 80 ppm of PB for 20 ppm of AA in the flours, without affecting the bread acceptability.

Community-based research initiatives in prevention

An overview of community-based action research projects is presented focusing on the community/research agenda interaction, the difficulties and rewards of this approach, and the unique opportunities of these projects. The potential for policy development as a result of these initiatives has not been fully explored, and some suggestions for the implementation of policies based on the results of action research projects are made. The policy implication of several specific interventions are discussed, along with the limitations and benefits of policy components within a project, rather than as spin-offs. The paper concludes with suggestions for planning community action projects to enhance the policy formulation aspect of these projects.

Acute nonlymphoblastic leukemia in children treated for acute lymphoblastic leukemia with an intensive regimen including teniposide

Some cases of conversion from acute lymphoblastic leukemia (ALL) to acute nonlymphoblastic leukemia (ANLL) at relapse have been reported recently. We report three cases initially diagnosed as having ALL and showing morphological, cytochemical, and immunophenotypic features of ANLL at relapse (lineage switch). Conversion was observed among 14 patients who developed bone marrow relapse while undergoing intensive treatment with our ALL protocol, which includes teniposide, and that had been administered to 62 patients. The three cases converted at first relapse, with a mean time of 20 months (13-29 months). Clinical and immunologic characteristics of T-cell leukemia were present in one patient. Changes documented in cytogenetic studies are discussed. The underlying mechanisms for the lineage switch remain unclear as does its relation with mixed lineage leukemias, but we believe that drugs employed in our therapy protocol could have had an influence on this conversion.

Antibodies to denatured type II collagen in rheumatoid arthritis: negative association with IgM rheumatoid factor

Serum samples from 129 patients with definite or classic rheumatoid arthritis (RA) were assayed by ELISA for antibodies to denatured bovine type II collagen (dII). All patients had active disease at the time of serum sampling. Anti-dII antibodies were found in 18 (14%) of 129 patients (95% confidence intervals: 8-20%). The only clinical or laboratory feature associated with the presence of anti-dII antibodies was seronegativity for IgM rheumatoid factor (IgM RF): 6 (37.5%) of 16 seronegative patients had anti-dII antibodies vs 12 (10.6%) of the 113 seropositive patients (OR = 5, p less than 0.01). There were no associations of anti-dII antibodies with age, sex, race, disease activity, disease duration, functional class, or the presence of HLA-DR1, DR4, or DQw3 in these patients. Antibodies to type II collagen may have a pathophysiologic role in RA, especially in patients seronegative for RF.

Hepatosplenic candidiasis in children with acute leukemia

Three children with acute lymphoblastic leukemia developed disseminated fungal disease predominantly involving the liver and spleen. The three patients were undergoing induction chemotherapy and had neutropenia when they presented prolonged fever not responsive to antibiotics. Once neutropenia was recovered, hepatosplenomegaly leukocytosis, elevated serum alkaline phosphatase, and hypoechoic areas in the spleen and liver ultrasound were observed. All fungal blood cultures were negative, with the diagnosis being confirmed by histologic study. One of the patients died without achieving control of the candidiasis. The other two patients received prolonged antifungal treatment concurrently with chemotherapy and both are alive, one of them cured and in complete remission. The increasing frequency of this infection in recent years and the importance of a prompt and prolonged administration of antifungal therapy to obtain the cure are discussed.

[Neonatal tumors]

We review the cases of congenital and neonatal tumors treated at the Children's Hospital La Fe, Valencia. A total of 25 cases of neonatal benign tumors and 27 cases of malignant tumors were diagnosed. The most frequent benign tumor was solid teratoma (12 cases). The most frequent malignant tumor was neuroblastoma (14 cases). Variations in histology, clinical evolution and therapy in relation to age are described. The results obtained are compared with those previously published.

[Gammagraphy with 123I-meta-iodobenzylguanidine in the diagnosis of pheochromocytoma]

At times pheochromocytoma raises diagnostic problems which cannot be solved by methods already incorporated into diagnostic evaluation, such as catecholamine measurement, echography and computed tomography. These drawbacks are more common with small size tumors, malignant extra-adrenal pheochromocytoma and some cases of relapse after surgery. The present study reports the results of 123I-meta-iodobenzylguanidine (MIBG) scintiscan in 30 patients with suspected pheochromocytoma. The head, the thorax and the abdomen were scanned in all patients after 3, 24 and 48 hours. Areas of normal and abnormal uptake were evaluated in these areas. The scintiscan was positive in seven cases with a diagnosis of pheochromocytoma, which showed markedly increased uptake persisting throughout the study. The results of other studies are analyzed and the functional character of MIBG, its sensitivity and specificity, and the advantages of 123I over 131I are discussed.