Targeting school tobacco policy: lessons from the Acadiana Coalition of Teens Against Tobacco (ACTT)

This case study examines the comparative effect of no-use school tobacco policies and restricted-use tobacco policies on teacher and student smoking behaviors and attitudes. Data from teachers (n = 1,041) and ninth-grade students (n = 4,763) at 20 schools in five districts in southern Louisiana were available. No significant difference was observed between teacher smoking (11% vs. 13%, p = .42) or student smoking (24.6% vs. 25.2%, p = .75) at no-use versus restricted-use policy schools. The proportion of teachers smoking on campus at no-use or restricted-use schools was not significantly different. Teachers at restricted-use schools were however less concerned about students seeing teachers smoke and less supportive of a no-use policy than teachers at no-use schools. Tobacco use policies are often not promoted, and enforcement of policies impacting teachers is complex. Changing social norms for smoking at high schools through policy promotion and enforcement is understudied.     

The rib-sparing technique for internal mammary vessel exposure in microsurgical breast reconstruction

The internal mammary vessels are frequently used for free flap breast reconstruction and are typically dissected via resection of an entire rib cartilage. Resection of rib cartilage may cause increased postoperative pain or a depressed thoracic contour deformity. We have used a new, less invasive technique that does not resect rib cartilage and exposes the vessels within the rib interspace.Over a 3-year period, all breast free flaps performed with the rib-sparing technique were reviewed and compared with a group of flaps performed with the standard rib resection technique. The rib-sparing technique was performed for 74 flaps, with no significant increase in complications, including revision of anastomosis (3%), fat necrosis (11%), or flap loss (1%), when compared with a group of 125 flaps undergoing rib resection. This less invasive technique is reviewed in detail and may prove beneficial in regard to postoperative pain and incidence of chest wall deformities.     

Predictors of Weight Regain and Insufficient Weight Loss According to Different Definitions After Sleeve Gastrectomy: a Retrospective Analytical Study

Background

Weight regain (WR) and insufficient weight loss (IWL) after sleeve gastrectomy (SG) are challenging issues. This study aimed to evaluate the predictors of WR and IWL after SG.

Methods

In this retrospective analytical study, 568 patients who underwent SG at Hazrat-e Rasool General Hospital, Tehran, Iran, between January 2015 and April 2022 were evaluated. A total of 333 patients were included. WR and IWL were evaluated by multiple criteria such as a BMI of > 35 kg/m², an increase in BMI of > 5 kg/m² above nadir, an increase in weight of > 10 kg above nadir, percentage of excess weight loss (%EWL) < 50% at 18 months, an increase in weight of > 25% of EWL from nadir at 36 months, and percentage of total weight loss (%TWL) < 20% at 36 months. All participants were followed up for 36 months.

Result

The univariate analysis showed that preoperative BMI, obstructive sleep apnea, metformin consumption, and grades 2 and 3 fatty liver disease were associated with WR and IWL (P < 0.05). WR or IWL incidence varied (0–19.3%) based on different definitions. The multivariate analysis showed that a preoperative BMI of > 45 kg/m² [odds ratio_Adjusted (OR_Adj) 1.77, 95% CI: 1.12–4.11, P = 0.038] and metformin consumption [OR_Adj: 0.48, 95% CI: 0.19–0.78, P = 0.001] were associated with WR and IWL after SG, regardless of the definition of WR or IWL.

Conclusion

This study showed that preoperative BMI of > 45 kg/m², obstructive sleep apnea, metformin consumption, and grades 2 and 3 of fatty liver disease were associated with WR or IWL.

Graphical abstract

     

A ridge-to-reef ecosystem microbial census reveals environmental reservoirs for animal and plant microbiomes

Microbes are found in nearly every habitat and organism on the planet, where they are critical to host health, fitness, and metabolism. In most organisms, few microbes are inherited at birth; instead, acquiring microbiomes generally involves complicated interactions between the environment, hosts, and symbionts. Despite the criticality of microbiome acquisition, we know little about where hosts’ microbes reside when not in or on hosts of interest. Because microbes span a continuum ranging from generalists associating with multiple hosts and habitats to specialists with narrower host ranges, identifying potential sources of microbial diversity that can contribute to the microbiomes of unrelated hosts is a gap in our understanding of microbiome assembly. Microbial dispersal attenuates with distance, so identifying sources and sinks requires data from microbiomes that are contemporary and near enough for potential microbial transmission. Here, we characterize microbiomes across adjacent terrestrial and aquatic hosts and habitats throughout an entire watershed, showing that the most species-poor microbiomes are partial subsets of the most species-rich and that microbiomes of plants and animals are nested within those of their environments. Furthermore, we show that the host and habitat range of a microbe within a single ecosystem predicts its global distribution, a relationship with implications for global microbial assembly processes. Thus, the tendency for microbes to occupy multiple habitats and unrelated hosts enables persistent microbiomes, even when host populations are disjunct. Our whole-watershed census demonstrates how a nested distribution of microbes, following the trophic hierarchies of hosts, can shape microbial acquisition.

Microbial partners metabolize our food, fight off disease, and run the machinery that sustains the air we breathe, water we drink, and soil under our feet. Despite their importance, most host-associated microbes are generally not present at birth and are instead acquired (1). Because microbial symbionts can influence host health and fitness, the processes that determine how different microbiomes assemble within different hosts is a matter of active and urgent inquiry. Microbial ecologists have made great progress in determining how factors such as abiotic conditions (2–4), host evolution (5, 6), and microbial traits (7–9) shape environmental microbiomes, but considerably less is known about how surrounding environments or different guilds of host organisms contribute to host-associated microbiome composition. Longitudinal studies show that microbial richness accumulates and community composition changes over time across a wide diversity of hosts and habitats (1), but we know comparatively little about from where these microbes originate. To better understand microbial transmission and its role in community composition, we propose a framework that relies on theory from foodweb and landscape ecology.The concept of a foodweb has had a place in the ecological lexicon since at least the time of Elton (1927; (10)), and others such as Lindeman (11) and Odum (12) significantly expanded upon this notion to include how macroorganisms interact within their environments, in addition to their feeding relationships. The units of study for foodwebs are ecosystems, which are spatially explicit and include all organisms along with their abiotic environments and their interactions within its bounds (13). This definition was born from the efforts of the founders of the Hubbard Brook Ecosystem Study (HBES; 1963), who recognized that a watershed naturally delineates the boundaries of an ecosystem, an idea that parallels the Hawaiian ahupuaʻa concept. Since then, the HBES and its framework have led to numerous milestones in our understanding of processes such as the effects of long-term changes in acidification (14) and ecosystem impacts of global warming (15). Here, we adopt the notion of the watershed as an entire discrete ecosystem to better understand the landscape ecology of microbes. Landscape ecology is a means to understand how spatial processes affect biodiversity (16). In classic landscape ecology theory, the structure (heterogeneity) and fragmentation of habitats (or patches) within a matrix of otherwise inhospitable areas affect species’ dispersal ability and establishment. This ultimately shapes species’ abundance and distributions across the landscape (17). Contemporary landscape ecology theory extends this idea to include the concept of a landscape continuum, where continuous environmental variables, as opposed to discrete habitat patches surrounded by a matrix, better describe species’ distributions. Connecting these concepts, foodwebs are embedded in landscapes, and watersheds constitute a useful unit of measure to better understand their interactions.To expand concepts from foodweb and landscape ecology to be inclusive of microbes, we must first consider the following: a landscape for microbes can be both structural (e.g., different land covers or hydrology) and biotic (e.g., variation in the distribution of host populations). Also, microbes might better fit a continuous landscape model rather than a patch model if their distributions are not governed merely by the presence of a compatible host or habitat, but rather, if they exist among multiple hosts across a gradient of environmental conditions. This requires microbes to be generalists to some degree and/or a matrix that is at least partially hospitable (18). These considerations are important because while microbial transmission among related hosts is one obvious means of microbiome assembly, this model, in and of itself, is insufficient to sustain microbiomes (defined here as communities of bacteria and archaea) across a dynamic landscape. For example, many plants and animals are either sparse, seasonal, or ephemeral, requiring that their symbiotic microbes be capable of residing, at times, in alternate nearby hosts or environments. This potential for a microbe to persist in, and disperse among, hosts of different kingdoms and guilds, or even between liquid and land, is a trait with the potential to add an additional dimension to microbiome assembly theory (19). Where, then, might a host’s microbes reside when not inside that host? In addition, what factors might predict microbiome distributions among potentially interacting hosts and environments?Variability in matrix suitability and host specialization may result in differing microbial communities reflected in one of three nonmutually exclusive patterns, each of which leaves a diagnostic imprint on microbiome structure. If any host or environment has an equal likelihood of harboring microbes that are present in any other host or environment, we might expect host–microbe interaction networks that are randomly structured. Alternatively, if microbes are more likely to co-occur among related hosts or guilds, we might expect these to contain unique and specific consortia of microbes (modules) that are not found elsewhere in the interaction network. Finally, host–microbe interactions might be best characterized as stratified, resulting in a network topology in which microbial diversity is nested such that taxa-poor microbiomes are subsets of those that are taxa-rich. In this scenario, nonhost environmental matrices (e.g., soil, sediment, water) serve as reservoirs of broad microbial diversity that is subsequently, and hierarchically, partitioned into simpler microbiomes. While this concept is fairly intuitive, there are actually few, if any, studies that demonstrate transmission among environmental microbiomes and multiple hosts at ecosystem scales. Instead, many of the insights gleaned into assembly processes of microbiomes are owed to studies of single hosts, tractable model systems, or global syntheses (20). We address this gap by sampling microbiomes from aquatic, marine, and terrestrial foodwebs within a single watershed to examine the dynamics of sources and sinks of microbial diversity.Here, we present a microbial census of a model ecosystem metacommunity in which continental-scale environmental heterogeneity is recapitulated within a comparatively small watershed. Because of this, we can surmise the distribution limits of microbiomes across land, stream, and sea, a feat that would not be plausible in most other landscapes of similar size or environmental variability. From ridge to reef, our compact watershed spans a roughly 3.5 m rainfall differential, ∼27 times that encountered along the Mississippi, the largest watershed in continental North America. Also, our model ecosystem is located on the most isolated archipelago on the planet, making exogenous microbial inputs infrequent, if not unlikely. Furthermore, owing to parallels in environmental heterogeneity and foodweb structure across this compact watershed compared to others, our findings are potentially relevant for highly connected ecosystems that span substantially larger geographic areas.For example, a long-standing question in biogeography is the relationship between organisms’ local distributions and those at larger scales. Many factors influence the distributions of microbes, including their physiology, size, population density, and dispersal abilities (21–23). A common assumption is that niche breadth should also predict the range size of an organism, since the ability to survive in broader environments, and to use a greater array of resources, should indicate the ability to occupy more habitats that occur over greater distances (24, 25). This is an important component of source and sink dynamics, because it suggests that local occupancy should predict global distributions. This relationship is seldom tested empirically, however, because small areas rarely contain, or are sampled for, broad climatic variability and host diversity. In the absence of phenotypic, genomic, or even well-resolved taxonomic information about the majority of the earth’s microbial biodiversity, geographic range is one of the few traits that can be directly inferred from short environmental DNA sequence reads. By examining our ecosystem-wide microbiome census within the context of the global survey of the Earth Microbiome Project (26), we assess the relationship between global and local microbial distributions.     

Association of the joint effect of menopause and hormone replacement therapy and cancer in African American women: the Jackson Heart Study

Cancer is the second leading cause of death in the US and in Mississippi. Breast cancer (BC) is the most common cancer among women, and the underlying pathophysiology remains unknown, especially among African American (AA) women. The study purpose was to examine the joint effect of menopause status (MS) and hormone replacement therapy (HRT) on the association with cancers, particularly BC using data from the Jackson Heart Study. The analytic sample consisted of 3202 women between 35 and 84 years of which 73.7% and 22.6% were postmenopausal and on HRT, respectively. There were a total of 190 prevalent cancer cases (5.9%) in the sample with 22.6% breast cancer cases. Menopause (p<0.0001), but not HRT (p=0.6402), was independently associated with cancer. Similar results were obtained for BC. BC, cancer, hypertension, type 2 diabetes, prevalent cardiovascular disease, physical activity and certain dietary practices were all significantly associated with the joint effect of menopause and HRT in the unadjusted analyses. The family history of cancer was the only covariate that was significantly associated with cancer in the age-adjusted models. In examining the association of cancer and the joint effect of menopause and HRT, AA women who were menopausal and were not on HRT had a 1.97 (95% CI: 1.15, 3.38) times odds of having cancer compared to pre-menopausal women after adjusting for age; which was attenuated after further adjusting for family history of cancer. Given that the cancer and BC cases were small and key significant associations were attenuated after adjusting for the above mentioned covariates, these findings warrant further investigation in studies with larger sample sizes of cancer (and BC) cases.     

A Cluster Randomized Trial of a Community-Based Intervention Among African-American Adults: Effects on Dietary and Physical Activity Outcomes

Prevention Science - Evidence of the effectiveness of community-based lifestyle behavior change interventions among African-American adults is mixed. We implemented a behavioral lifestyle change...     

Putting genetic interactions in context through a global modular decomposition

Genetic interactions provide a powerful perspective into gene function, but our knowledge of the specific mechanisms that give rise to these interactions is still relatively limited. The availability of a global genetic interaction map in Saccharomyces cerevisiae, covering ～30% of all possible double mutant combinations, provides an unprecedented opportunity for an unbiased assessment of the native structure within genetic interaction networks and how it relates to gene function and modular organization. Toward this end, we developed a data mining approach to exhaustively discover all block structures within this network, which allowed for its complete modular decomposition. The resulting modular structures revealed the importance of the context of individual genetic interactions in their interpretation and revealed distinct trends among genetic interaction hubs as well as insights into the evolution of duplicate genes. Block membership also revealed a surprising degree of multifunctionality across the yeast genome and enabled a novel association of VIP1 and IPK1 with DNA replication and repair, which is supported by experimental evidence. Our modular decomposition also provided a basis for testing the between-pathway model of negative genetic interactions and within-pathway model of positive genetic interactions. While we find that most modular structures involving negative genetic interactions fit the between-pathway model, we found that current models for positive genetic interactions fail to explain 80% of the modular structures detected. We also find differences between the modular structures of essential and nonessential genes.