Importance
Potentially malignant disorders of the oral cavity (OPMD) are a heterogeneous group of lesions associated with a variable risk of malignant transformation (MT) to invasive cancer. ...Leukoplakia (LE), lichen planus (LP), oral lichenoid lesions (OLL), oral erythroplakia (OE), oral submucous fibrosis (OSF), and proliferative verrucous leukoplakia (PVL) are among the most common of these lesions. Oral dysplasia is a mucosal area characterized by cellular and architectural derangement, which may be associated with OPMDs or not.
Objective
To define the MT rate of OPMDs and the risk of development into cancer of mild vs moderate/severe oral dysplasia. This in order to implement adequate follow‐up strategies and treatment decisions.
Study design
We performed a systematic review and meta‐analysis on studies reporting the MT rates of OPMDs and oral dysplasia. Ninety‐two studies were included for the analysis. Cumulative rates were reported for OPMDs overall and as a subgroup, a comparison was made of mild vs moderate/severe dysplasia. Meta‐regression on OPMD and year of publication was also performed.
Main outcome and measures
Overall MT rates of OPMDs and odds ratio of MT of mild vs moderate/severe dysplasia.
Results
Overall MT rate across all OPMD groups was 7.9% (99% confidence interval CI 4.9%‐11.5%). MT rates of the specific OPMD subgroups were as follows: LP 1.4% (99% CI 0.9%‐1.9%), LE 9.5 (5.9%‐14.00%), OLL 3.8% (99% CI 1.6%‐7.00%), OSF 5.2% (99% CI 2.9%‐8.00%), OE 33.1% (99% CI 13.6%‐56.1%), and PVL 49.5% (99% CI 26.7%‐72.4%). Regarding the dysplasia grades comparison, the meta‐analysis showed that moderate/severe dysplasia is meaningfully associated to a much greater risk of MT compared to mild dysplasia with an odds ratio of 2.4 (95% CI 1.5‐3.8) Correction added on 27 December 2019, after first online publication: CI updated from 99% to 95%.. Heterogeneity was not significant. Annual MT rates were approximated based on the average follow‐up as reported in the various subgroups. Lichen planus had an annual MT of 0.28%, OLL of 0.57%, leukoplakia of 1.56%, PVL of 9.3%, and OSF of 0.98%. Mild dysplasia had an annual MT of 1.7%, while severe dysplasia of 3.57%. Meta‐regression showed a significant negative correlation of PVL MT rate and year of the study (P value <.001).
Conclusions and relevance
OPMDs and oral dysplasia are relatively common conditions that general practitioners, head and neck, and oral medicine specialists, face in their everyday practice. Our analysis confirms the significant risk of MT of these lesions, although variable among the subgroups. Moderate/severe dysplasia bears a much higher risk of cancer evolution than mild dysplasia. It is important to raise public health awareness on the MT rates of these conditions, at the same time efficacious communication with the patient is of utmost importance. This, coupled with strict follow‐up measures and optimal treatment strategies, would help in reducing the transformation of these oral conditions into invasive cancer.
Summary
Shifts in flowering phenology are important indicators of climate change. However, the role of precipitation in driving phenology is far less understood compared with other environmental ...cues, such as temperature.
We use a precipitation reduction gradient to test the direction and magnitude of effects on reproductive phenology and reproduction across 11 plant species in a temperate grassland, a moisture‐limited ecosystem. Our experiment was conducted in a single, relatively wet year. We examine the effects of precipitation for species, functional types, and the community.
Our results provide evidence that reduced precipitation shifts phenology, alters flower and fruit production, and that the magnitude and direction of the responses depend on functional type and species. For example, early‐blooming species shift toward earlier flowering, whereas later‐blooming species shift toward later flowering. Because of opposing species‐level shifts, there is no overall shift in community‐level phenology.
This study provides experimental evidence that changes in rainfall can drive phenological shifts. Our results additionally highlight the importance of understanding how plant functional types govern responses to changing climate conditions, which is relevant for forecasting phenology and community‐level changes. Specifically, the implications of divergent phenological shifts between early‑ and late‐flowering species include resource scarcity for pollinators and seed dispersers and new temporal windows for invasion.
Aim
The COVID‐19 pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) has put health care workers at risk when exposed to aerosolized viral particles during upper ...airway mucosal surgery. The objective of this review was to discuss topical preparations that could be utilized preoperatively to help to decrease viral load and potentially reduce the risks of viral transmission.
Methods
A PubMed/MEDLINE database review of articles was performed querying topical preparations with virucidal activity against coronaviruses.
Results
Povidone‐iodine (PVP‐I) solutions ranging from 0.23% to 7% have been found to demonstrate highly effective virucidal activity against a broad range of viruses including several coronaviruses responsible for recent epidemics including SARS‐CoV‐1 and MERS‐CoV.
Conclusions
While specific evidence regarding SARS‐CoV‐2 is lacking, PVP‐I‐based preparations have been successfully demonstrated to reduce viral loads of coronaviruses. They are relatively safe to use in the upper airway and may reduce risk of SARS‐CoV‐2 aerosolization during upper airway mucosal surgery.
To what extent microbial community composition can explain variability in ecosystem processes remains an open question in ecology. Microbial decomposer communities can change during litter ...decomposition due to biotic interactions and shifting substrate availability. Though relative abundance of decomposers may change due to mixing leaf litter, linking these shifts to the non-additive patterns often recorded in mixed species litter decomposition rates has been elusive, and links community composition to ecosystem function. We extracted phospholipid fatty acids (PLFAs) from single species and mixed species leaf litterbags after 10 and 27 months of decomposition in a mixed conifer forest. Total PLFA concentrations were 70% higher on litter mixtures than single litter types after 10 months, but were only 20% higher after 27 months. Similarly, fungal-to-bacterial ratios differed between mixed and single litter types after 10 months of decomposition, but equalized over time. Microbial community composition, as indicated by principal components analyses, differed due to both litter mixing and stage of litter decomposition. PLFA biomarkers a15∶0 and cy17∶0, which indicate gram-positive and gram-negative bacteria respectively, in particular drove these shifts. Total PLFA correlated significantly with single litter mass loss early in decomposition but not at later stages. We conclude that litter mixing alters microbial community development, which can contribute to synergisms in litter decomposition. These findings advance our understanding of how changing forest biodiversity can alter microbial communities and the ecosystem processes they mediate.
Global change is altering species distributions and thus interactions among organisms. Organisms live in concert with thousands of other species, some beneficial, some pathogenic, some which have ...little to no effect in complex communities. Since natural communities are composed of organisms with very different life history traits and dispersal ability it is unlikely they will all respond to climatic change in a similar way. Disjuncts in plant-pollinator and plant-herbivore interactions under global change have been relatively well described, but plant-soil microorganism and soil microbe-microbe relationships have received less attention. Since soil microorganisms regulate nutrient transformations, provide plants with nutrients, allow co-existence among neighbors, and control plant populations, changes in soil microorganism-plant interactions could have significant ramifications for plant community composition and ecosystem function. In this paper we explore how climatic change affects soil microbes and soil microbe-plant interactions directly and indirectly, discuss what we see as emerging and exciting questions and areas for future research, and discuss what ramifications changes in these interactions may have on the composition and function of ecosystems.
The interactive effects of diversity in plants and microbial communities at the litter interface are not well understood. Mixtures of plant litter from different species often decompose differently ...than when individual species decompose alone. Previously, we found that litter mixtures of multiple conifers decomposed more rapidly than expected, but litter mixtures that included conifer and aspen litter did not. Understanding the mechanisms underlying these diversity effects may help explain existing anomalous decay dynamics and provide a glimpse into the elusive linkage between plant diversity and the fungi and bacteria that carry out decomposition. We examined the microbial communities on litter from individual plant species decomposing both in mixture and alone. We assessed two main hypotheses to explain how the decomposer community could stimulate mixed-litter decomposition above predicted rates: either by being more abundant, or having a different or more diverse community structure than when microbes decompose a single species of litter. Fungal, bacterial and total phospholipid fatty acid microbial biomass increased by over 40% on both conifer and aspen litter types in mixture, and microbial community composition changed significantly when plant litter types were mixed. Microbial diversity also increased with increasing plant litter diversity. While our data provide support for both the increased abundance hypothesis and the altered microbial community hypothesis, microbial changes do not translate to predictably altered litter decomposition and may only produce synergisms when mixed litters are functionally similar.
Understanding how altered soil organic carbon (SOC) availability affects microbial communities and their function is imperative in predicting impacts of global change on soil carbon (C) storage and ...ecosystem function. However, the response of soil microbial communities and their function to depleted C availability in situ is unclear. We evaluated the role of soil C inputs in controlling microbial biomass, community composition, physiology, and function by (1) experimentally excluding plant C inputs in situ for 9 yr in four temperate forest ecosystems along a productivity gradient in Oregon, USA; and (2) integrating these findings with published data from similar C-exclusion studies into a global meta-analysis. Excluding plant C inputs for 9 yr resulted in a 13% decrease in SOC across the four Oregon sites and an overall shift in the microbial community composition, with a 45% decrease in the fungal : bacterial ratio and a 13% increase in Gram-positive : Gram-negative bacterial ratio. Although gross N mineralization decreased under C exclusion, decreases in gross N immobilization were greater, resulting in increased net N mineralization rates in all but the lowest-productivity site. Microbial biomass showed a variable response to C exclusion that was method dependent; however, we detected a 29% decrease in C-use efficiency across the sites, with greater declines occurring in less-productive sites. Although extracellular enzyme activity increased with C exclusion, C exclusion resulted in a 31% decrease in microbial respiration across all sites. Our meta-analyses of published data with similar C-exclusion treatments were largely consistent with our experimental results, showing decreased SOC, fungal : bacterial ratios, and microbial respiration, and increased Gram-positive : Gram-negative bacterial ratio following exclusion of C inputs to soil. Effect sizes of SOC and respiration correlated negatively with the duration of C exclusion; however, there were immediate effects of C exclusion on microbial community composition and biomass that were unaltered by duration of treatment. Our field-based experimental results and analyses demonstrate unequivocally the dominant control of C availability on soil microbial biomass, community composition, and function, and provide additional insight into the mechanisms for these effects in forest ecosystems.
Objective
To analyze the patterns, risk factors, and salvage outcomes for locoregional recurrences (LRR) after treatment with transoral robotic surgery (TORS) for HPV‐associated oropharyngeal ...squamous cell carcinoma (HPV+ OPSCC).
Study Design
Retrospective analysis of HPV+ OPSCC patients completing primary TORS, neck dissection, and NCCN‐guideline‐compliant adjuvant therapy at a single institution from 2007 to 2017.
Methods
Features associated with LRR, detailed patterns of LRR, and outcomes of salvage therapy were analyzed. Disease‐free survival (DFS) and overall survival (OS) were calculated for subgroups of patients receiving distinct adjuvant treatments.
Results
Of 541 patients who completed guideline‐indicated therapy, the estimated 5‐year LRR rate was 4.5%. There were no identifiable clinical or pathologic features associated with LRR. Compared to patients not receiving adjuvant therapy, those who received indicated adjuvant radiation alone had a lower risk of LRR (HR 0.28, 95% CI 0.09–0.83, P = .023), but there was no difference in DFS (P = .21) and OS (P = .86) between adjuvant therapy groups. The 5‐year OS for patients who developed LRR was 67.1% vs. 93.9% for those without LRR (P < .001). Patients who initially received adjuvant chemoradiation and those suffering local, in‐field, and/or retropharyngeal node recurrences had decreased disease control after salvage therapy.
Conclusion
LRR rates are low for HPV+ OPSCCs completing TORS and guideline‐compliant adjuvant therapy. Patients without indication for adjuvant therapy more often suffer LRR, but these recurrences are generally controllable by salvage therapy. Improved understanding of the patterns of recurrence most amenable to salvage therapy may guide treatment decisions, counseling, and adjuvant therapy de‐escalation trials.
Level of Evidence
3 Laryngoscope, 131:E2865–E2873, 2021
Models of ecosystem development and response to environmental variation must incorporate change in vertical soil space as well as over time. Insufficient measurement of subsurface soil properties ...represents a major observational bias in ecosystem studies.
We address these changes in horizontal (time) and vertical (soil profile) space along a three‐million‐year, semi‐arid, piñon‐juniper woodland substrate age gradient with characteristic progressive and retrogressive ecosystem development phases and a shift from nitrogen (N) and water to phosphorus (P) limitation. We present a novel pedological approach using isotopic tracers and biogeochemical analyses to address fine root distribution, depth of plant uptake and relative nutrient availabilities.
We show that (a) the quantity of fine roots remains constant with ecosystem development but their distribution in the soil profile becomes increasingly deeper and less concentrated in the surface soil; (b) mean depth of tree uptake becomes deeper with substrate age and follows the relative availability of P as P‐limitation develops and (c) soil P transformations in the oldest soil profiles resemble the theoretical changes with age to produce a depth gradient of relative N and P availability.
Synthesis. The expanding role of deep roots in this model system is tightly linked to phases of ecosystem development and relative nutrient availability. The inclusion of whole soil profiles is vital to investigating the intersections of biota, soil and geologic substrate and developing a more complete understanding of ecosystem structure and function.
The distribution of fine roots and mean depth of plant uptake shifted increasingly deeper during ecosystem development. The inclusion of whole soil profiles is vital to investigating the intersections of biota, soil and geologic substrate and developing a more complete understanding of ecosystem structure and function.
Current nationwide epidemiological data regarding ankle fractures are scarce. Such information is important towards better quantifying the mortality associated with such injuries, financial impact, ...as well as the implementation of preventative measures. This study evaluated the epidemiology of ankle fractures that occurred during a 5-year period. Specifically, we evaluated demographics, mechanism of injury, and disposition. The National Electronic Injury Surveillance System was queried to identify all patients with ankle fractures that presented to US hospital emergency departments between 2012 and 2016. Census data were used to determine the incidence rates of ankle fractures in terms of age, sex, and race. There was an estimated total of 673,214 ankle fractures that occurred during this period, with an incidence rate of 4.22/10,000 person-years. The mean age of patients with an ankle fracture was 37 ± 22.86 (SD) years; 23.5% of ankle fractures occurred in patients aged 10 to 19 years (7.56/10,000 person-years). In addition, 44% of ankle fractures occurred in men (3.81/10,000 person-years), whereas 56% occurred in women (4.63/10,000 person-years). Data on race/ethnicity were available for 71% of the subjects, with incidence rates of 2.85/10,000 person-years for whites, 3.01/10,000 person-years for blacks, and 4.08/10,000 person-years for others. The most common mechanism of injury was falls (54.83%), followed by sports (20.76%), exercise (16.84%), jumping (4.42%), trauma (2.84%), and other (0.30%). For disposition, 81.84% of patients were treated and released, 1.43% were transferred, 16.01% were admitted, 0.59% were held for observation, and 0.13% left against medical advice. The highest incidence of ankle fractures in men occurred in the 10-to-19-years age group, but women were more commonly affected in all other age groups.
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