The management of stage I Non-Small cell lung cancer (NSCLC) in Ontario: A Population-Based study of patterns of care and Stereotactic Ablative Body radiotherapy (SABR) utilization from 2010 to 2019

BACKGROUND

Stereotactic Ablative Body Radiotherapy (SABR) is the standard of care for medically inoperable patients with Stage I NSCLC. The adoption of SABR and its association with cancer outcomes requires characterization.

AIM

We described the management of biopsy-proven Stage I NSCLC with SABR, surgery, non-SABR curative radiotherapy (RT) and observation in Ontario, Canada, between 2010 and 2019. Temporal and geographic trends in practice and survival outcomes were analyzed.

METHODS

This was a retrospective population-based cohort study conducted by linking electronic radiotherapy (RT) records to a population-based cancer registry.

RESULTS

A total of 12,065 patients were identified, 61.7 % underwent surgery, 17.9 % received SABR, 8.6 % received non-SABR curative RT and 11.7 % were observed. Between 2010 and 2019, the utilization of surgery decreased (63.8 % to 49.9 %, p < 0.0001), while SABR use increased (7.5 % to 24.4 %, p < 0.0001), non-SABR curative RT use increased (6.7 % to 9.6 %, p < 0.0014) and patients observed decreased (14.4 % to 12.0 %, p < 0.0001). Substantial variation in practice exists across Ontario. Two- yr CSS improved for the entire cohort (81.9 % to 85.0 %, p < 0.0001). While there was improvement in 2 yr CSS for surgical patients (92.1 %% to 95.7 %, p < 0.001), survival for patients who received SABR, Non-SABR curative RT and observation remained stable.

CONCLUSION

There has been an increase in SABR utilization and a reduction in surgical utilization with a corresponding increased survival of stage I patients in Ontario between 2010 and 2019. Substantial differences in practice patterns exist across health regions, suggesting the need for strategies to improve access to SABR in many jurisdictions.

The interaction of climate, plant, and soil factors drives putative soil fungal pathogen diversity and community structure in dry grasslands

Soil pathogens play important roles in shaping soil microbial diversity and controlling ecosystem functions. Though climate and local environmental factors and their influences on fungal pathogen communities have been examined separately, few studies explore the relative contributions of these factors. This is particularly crucial in eco-fragile regions, which are more sensitive to environmental changes. Herein we investigated the diversity and community structure of putative soil fungal pathogens in cold and dry grasslands on the Tibetan Plateau, using high-throughput sequencing. The results showed that steppe soils had the highest diversity of all pathogens and plant pathogens; contrastingly, meadow soils had the highest animal pathogen diversity. Structural equation modelling revealed that climate, plant, and soil had similar levels of influence on putative soil fungal pathogen diversity, with total effects ranging from 52% to 59% (all p < 0.001), with precipitation exhibiting a stronger direct effect than plant and soil factors. Putative soil fungal pathogen community structure gradually changed with desert, steppe, and meadow, and was primarily controlled by the interactions of climate, plant, and soil factors rather than by distinct factors individually. This finding contrasts with most studies of soil bacterial and fungal community structure, which generally report dominant roles of individual environmental factors.

Real-world outcomes associated with bevacizumab combined with chemotherapy in platinum-resistant ovarian Cancer

OBJECTIVES

The addition of bevacizumab to chemotherapy for platinum-resistant (PL-R) ovarian cancer (OC) improved progression-free (PFS) but not overall survival (OS) in clinical trials. We explored real-world outcomes in Ontario, Canada, and compared survival in the pre- and post-bevacizumab era.

METHODS

Administrative databases were utilized to identify all patients treated with bevacizumab for PL-R OC. Time on treatment (ToT) was used as surrogate for PFS. Median OS was determined using the Kaplan-Meier method. Factors associated with ToT/OS were identified using a Cox proportional hazard model. A before and after comparative effectiveness analysis was performed to determine mOS for patients treated pre- and post-bevacizumab approval.

RESULTS

From 2017 to 2019, 176 patients received bevacizumab. Median ToT was 3 months and OS was 11 months. Sixty-four percent received liposomal doxorubicin and 34% received paclitaxel. ToT (6 vs 3 months; HR 0.44; p < 0.0001) and OS (14 vs 9 months; HR 0.45; p = 0.0089) were longer with bevacizumab/paclitaxel. OS was not significantly different pre- and post-bevacizumab funding (8 vs 9 months; HR 1.01; 0.937). Median OS increased for those receiving paclitaxel (6 vs 11 months), but those in the post group were younger, more likely to have undergone primary surgery and had less co-morbidities.

CONCLUSION

Real-world outcomes with bevacizumab in PL-R OC are inferior to those in the pivotal clinical trial. Survival has not significantly improved since funding became publicly available, indicating a substantial efficacy-effectiveness gap between trial and real-world outcomes. Median OS and ToT were significantly better when bevacizumab was given with paclitaxel.

Biogeographic survey of soil bacterial communities across Antarctica

BACKGROUND

Antarctica and its unique biodiversity are increasingly at risk from the effects of global climate change and other human influences. A significant recent element underpinning strategies for Antarctic conservation has been the development of a system of Antarctic Conservation Biogeographic Regions (ACBRs). The datasets supporting this classification are, however, dominated by eukaryotic taxa, with contributions from the bacterial domain restricted to Actinomycetota and Cyanobacteriota. Nevertheless, the ice-free areas of the Antarctic continent and the sub-Antarctic islands are dominated in terms of diversity by bacteria. Our study aims to generate a comprehensive phylogenetic dataset of Antarctic bacteria with wide geographical coverage on the continent and sub-Antarctic islands, to investigate whether bacterial diversity and distribution is reflected in the current ACBRs.

RESULTS

Soil bacterial diversity and community composition did not fully conform with the ACBR classification. Although 19% of the variability was explained by this classification, the largest differences in bacterial community composition were between the broader continental and maritime Antarctic regions, where a degree of structural overlapping within continental and maritime bacterial communities was apparent, not fully reflecting the division into separate ACBRs. Strong divergence in soil bacterial community composition was also apparent between the Antarctic/sub-Antarctic islands and the Antarctic mainland. Bacterial communities were partially shaped by bioclimatic conditions, with 28% of dominant genera showing habitat preferences connected to at least one of the bioclimatic variables included in our analyses. These genera were also reported as indicator taxa for the ACBRs.

CONCLUSIONS

Overall, our data indicate that the current ACBR subdivision of the Antarctic continent does not fully reflect bacterial distribution and diversity in Antarctica. We observed considerable overlap in the structure of soil bacterial communities within the maritime Antarctic region and within the continental Antarctic region. Our results also suggest that bacterial communities might be impacted by regional climatic and other environmental changes. The dataset developed in this study provides a comprehensive baseline that will provide a valuable tool for biodiversity conservation efforts on the continent. Further studies are clearly required, and we emphasize the need for more extensive campaigns to systematically sample and characterize Antarctic and sub-Antarctic soil microbial communities. Video Abstract.

Diazotrophic abundance and community structure associated with three meadow plants on the Qinghai-Tibet Plateau

Symbiotic diazotrophs form associations with legumes and substantially fix nitrogen into soils. However, grasslands on the Qinghai-Tibet Plateau are dominated by non-legume plants, such as Kobresia tibetica. Herein, we investigated the diazotrophic abundance, composition, and community structure in the soils and roots of three plants, non-legume K. tibetica and Kobresia humilis and the legume Oxytropis ochrocephala, using molecular methods targeting nifH gene. Diazotrophs were abundantly observed in both bulk and rhizosphere soils, as well as in roots of all three plants, but their abundance varied with plant type and soil. In both bulk and rhizosphere soils, K. tibetica showed the highest diazotroph abundance, whereas K. humilis had the lowest. In roots, O. ochrocephala and K. humilis showed the highest and the lowest diazotroph abundance, respectively. The bulk and rhizosphere soils exhibited similar diazotrophic community structure in both O. ochrocephala and K. tibetica, but were substantially distinct from the roots in both plants. Interestingly, the root diazotrophic community structures in legume O. ochrocephala and non-legume K. tibetica were similar. Diazotrophs in bulk and rhizosphere soils were more diverse than those in the roots of three plants. Rhizosphere soils of K. humilis were dominated by Actinobacteria, while rhizosphere soils and roots of K. tibetica were dominated by Verrumicrobia and Proteobacteria. The O. ochrocephala root diazotrophs were dominated by Alphaproteobacteria. These findings indicate that free-living diazotrophs abundantly and diversely occur in grassland soils dominated by non-legume plants, suggesting that these diazotrophs may play important roles in fixing nitrogen into soils on the plateau.

Precipitation Drives Soil Protist Diversity and Community Structure in Dry Grasslands

Protists are essential components of soil microbial communities, mediating nutrient cycling and ecosystem functions in terrestrial ecosystems. However, their distribution patterns and driving factors, particularly, the relative importance of climate, plant and soil factors, remain largely unknown. This limits our understanding of soil protist roles in ecosystem functions and their responses to climate change. This is particularly a concern in dryland ecosystems where soil microbiomes are more important for ecosystem functions because plant diversity and growth are heavily constrained by environmental stresses. Here, we explored protist diversity and their driving factors in grassland soils on the Tibetan Plateau, which is a typical dryland region with yearly low temperatures. Soil protist diversity significantly decreased along the gradient of meadow, steppe, and desert. Soil protist diversity positively correlated with precipitation, plant biomass and soil nutrients, but these correlations were changed by grazing. Structural equation and random forest models demonstrated that precipitation dominated soil protist diversity directly and indirectly by influencing plant and soil factors. Soil protist community structure gradually shifted along meadow, steppe and desert, and was driven more by precipitation than by plant and soil factors. Soil protist community compositions were dominated by Cercozoa, Ciliophora and Chlorophyta. In particular, Ciliophora increased but Chlorophyta decreased in relative abundance along the gradient of meadow, steppe and desert. These results demonstrate that precipitation plays more important roles in driving soil protist diversity and community structure than plant and soil factors, suggesting that future precipitation change profoundly alters soil protist community and functions in dry grasslands.

Identification of a novel PTH1R variant in a family with primary failure of eruption

BACKGROUND

Primary failure of tooth eruption (PFE) is a rare autosome genetic disorder that causes open bite. This work aimed to report a small family of PFE(OMIM: # 125,350) with a novel PTH1R variant. One of the patients has a rare clinical phenotype of the anterior tooth involved only.

CASE PRESENTATION

The proband was a 13-year-old young man with an incomplete eruption of the right upper anterior teeth, resulting in a significant open-bite. His left first molar partially erupted. Family history revealed that the proband's 12-year-old brother and father also had teeth eruption disorders. Genetic testing found a novel PTH1R variant (NM_000316.3 c.1325-1336del), which has never been reported before. The diagnosis of PFE was based on clinical and radiographic characteristics and the result of genetic testing. Bioinformatic analysis predicted this variant would result in the truncation of the G protein-coupled receptor encoded by the PTH1R, affecting its structure and function.

CONCLUSION

A novel PTH1R variant identified through whole-exome sequencing further expands the mutation spectrum of PFE. Patients in this family have different phenotypes, which reflects the characteristics of variable phenotypic expression of PFE.

Diversity and succession of chemolithoautotrophic microbial community along a recently deglaciation chronosequence on the Tibetan Plateau

Glaciers in high altitude mountain regions are retreating rapidly due to global warming, exposing deglaciated soils to extreme environmental conditions and microbial colonization. However, knowledge about chemolithoautotrophic microbes, which play important roles in the development of oligotrophic deglaciated soils prior to plant colonization, remains elusive in deglaciated soils. Using real-time quantitative PCR and clone library methods, the diversity and succession of the chemolithoautotrophic microbial community harboring the cbbM gene across a 14-year deglaciation chronosequence on the Tibetan Plateau were determined. The abundance of cbbM gene remained stable for the first 8 years after deglaciation and then increased significantly, ranging from 105 to 107 gene copies g-1 soil (P<0.001). Soil total carbon increased gradually to 5-year deglaciation and then decreased. While total nitrogen and total sulfur levels were low throughout the chronosequence. Chemolithoautotrophs were related to Gammaproteobacteria and Betaproteobacteria, with the former dominating early deglaciated soils and the latter dominating older deglaciated soils. The diversity of chemolithoautotrophs was high in mid-age deglaciated soils (6-year old) and was low in early (3-year old) and older deglaciated soils (12-year old). Our findings revealed that chemolithoautotrophic microbes colonize deglaciated soils quickly and follow a clear successional pattern across recently deglaciated chronosequences.

Controls on diversity of core and indicative microbial subcommunities in Tibetan Plateau grassland soils

Core subcommunity represents the less diversity but high abundance, while indicative subcommunity is highly diverse but low abundance in soils. The core subcommunity fundamentally maintains ecosystem stability, while the indicative plays important roles in vital ecosystem functions and is more sensitive to environmental change. However, their environmental driving factors and responses to human disturbances remain less defined. Herein, we explored the patterns of core and indicative soil microbes and their responses to animal grazing in dry grasslands across the Tibetan Plateau, using the Illumina sequencing of 16S rRNA gene. The results revealed that the core subcommunity diversity and richness were lower than the indicative in soils. The indicative subcommunity diversity exhibited substantially stronger correlations with nutrient-associated factors than the core diversity, including soil organic carbon, nitrogen, and plant biomass. The core and indicative microbial subcommunities both strongly varied with grassland ecosystems, while the latter was also significantly influenced by grazing. The variation partitioning analysis revealed that indicative microbial subcommunity was explained less by environmental factors than core subcommunity (34.5% vs 73.0%), but more influenced by grazing (2.6% vs 0.1%). Our findings demonstrated that the indicative microbes were particularly sensitive to soil nutrient-associated factors and human disturbances in alpine dry grasslands.

Characterizing Variability in Lung Cancer Outcomes and Influence of a Lung Diagnostic Assessment Program in Southeastern Ontario, Canada

INTRODUCTION

Regional variability in lung cancer (LC) outcomes exists across Canada, including in the province of Ontario. The Lung Diagnostic Assessment Program (LDAP) in southeastern (SE) Ontario is a rapid-assessment clinic that expedites the management of patients with suspected LC. We evaluated the association of LDAP management with LC outcomes, including survival, and characterized the variability in LC outcomes across SE Ontario.

METHODS

We conducted a population-based retrospective cohort study by identifying patients with newly diagnosed LC through the Ontario Cancer Registry (January 2017-December 2019) and linked to the LDAP database to identify LDAP-managed patients. Descriptive data were collected. Using a Cox model approach, we compared 2-year survival for patients managed through LDAP vs. non-LDAP.

RESULTS

We identified 1832 patients, 1742 of whom met the inclusion criteria (47% LDAP-managed and 53% non-LDAP). LDAP management was associated with a lower probability of dying at 2 years (HR 0.76 vs. non-LDAP, p < 0.0001). Increasing distance from the LDAP was associated with a lower likelihood of LDAP management (OR 0.78 for every 20 km increase, p < 0.0001). LDAP-managed patients were more likely to receive specialist assessment and undergo treatments.

CONCLUSIONS

In SE Ontario, initial diagnostic care provided via LDAP was independently associated with improved survival in patients with LC.

Real-world outcomes associated with use of front-line bevacizumab in ovarian cancer

BACKGROUND

In the pivotal ICON7 study, addition of bevacizumab to front-line treatment of ovarian cancer (OC) significantly improved overall survival (OS) (p=0.03) in a high-risk subgroup of patients with suboptimally debulked/unresectable stage III or IV disease, leading to approval in Ontario, Canada in March 2016. Here we describe utilization of bevacizumab for front-line, high-risk OC and determine outcomes in routine clinical practice.

METHODS

Provincial administrative databases were utilized to identify all patients treated with front-line bevacizumab following its approval. Median OS (mOS) was determined using the Kaplan-Meier method. Factors associated with OS were identified using a Cox proportional hazard model. A comparative effectiveness analysis was performed to determine mOS pre- (2006-2016) and post- (2016-2019) approval.

RESULTS

From March 2016 to October 2019, 282 patients received bevacizumab. Mean age was 64 years old, and 58% had stage IV disease. Median survival was 29 months and was longer in stage III (37 months) compared to stage IV disease (28 months). In a comparative effectiveness analysis of patients with stage IV serous OC, post-approval uptake of bevacizumab was low (23%). Median OS was similar pre (26 months) and post (27 months) approval (HR 0.92, 0.75-1.12, p=0.383).

CONCLUSIONS

Survival in real-world patients treated with front-line bevacizumab is shorter than in pivotal clinical trials. Survival in stage IV serous patients has not significantly improved post public reimbursement of bevacizumab. This analysis was limited by poor uptake, however mOS was similar in patients who did and did not receive bevacizumab.

Palliative Radiotherapy for Esophageal and Gastric Cancer: Population-Based Patterns of Utilization and Outcomes in Ontario, Canada

OBJECTIVE

Patients with incurable esophageal and gastric cancer may develop local symptoms for which palliative radiotherapy (PRT) may be considered. We sought to evaluate patterns in utilization and outcomes of patients receiving PRT for incurable esophageal and gastric cancer in Ontario, Canada using health administrative data.

METHODS

Linked health administrative databases were used to identify patients receiving PRT for incurable esophageal and gastric cancer. Primary outcomes were utilization and delivery of PRT, utilization of endoscopic dilation with or without stent insertion after completion of PRT and survival from 1) date of diagnosis and 2) start of PRT.

RESULTS

We identified 2500 patients who received PRT. Mean age was 70 ± 13 years and the majority (75%, n = 1873/2500) were male. Over half of the patients had a diagnosis of gastric cancer (58%, n = 1453/2500) and began PRT within 6 months of cancer diagnosis (85%, n = 2125/2500). Of the 2500 patients in the cohort, 2174 patients received EBRT with few receiving brachytherapy (n = 326) or EBRT and brachytherapy combined (n = 88). Over the study period, there was an increase in the number of patients receiving PRT (136 in 2007 to 290 in 2016), as well as in the use of advanced conformal radiotherapy techniques. Only 5% (115/2500) required dilation with or without stent insertion after completion of PRT. Median overall and cancer-specific survival of the cohort was 205 days and 209 days from date of diagnosis and 108 days and 110 days from start of PRT.

CONCLUSIONS

PRT is an important treatment for patients with incurable esophageal and gastric cancer who present with local symptoms. Utilization of PRT and advanced EBRT techniques increased over the study period. Few patients require endoscopic dilation with or without stent insertion after completion of PRT suggesting that PRT provides favorable symptom control.

Grazing greatly reduces the temporal stability of soil cellulolytic fungal community in a steppe on the Tibetan Plateau

Excessive livestock grazing degrades grasslands ecosystem stability and sustainability by reducing soil organic matter and plant productivity. However, the effects of grazing on soil cellulolytic fungi, an important indicator of the degradation process for soil organic matter, remain less well understood. Using T-RFLP and sequencing methods, we investigated the effects of grazing on the temporal changes of cellulolytic fungal abundance and community structure in dry steppe soils during the growing months from May to September, on the Tibetan Plateau using T-RFLP and sequencing methods. The results demonstrated that the abundance of soil cellulolytic fungi under grazing treatment changed significantly from month to month, and was positively correlated with dissolved organic carbon (DOC) and soil temperature, but negatively correlated with soil pH. Contrastingly, cellulolytic fungal abundance did not change within the fencing treatment (ungrazed conditions). Cellulolytic fungal community structure changed significantly in the growing months in grazed soils, but did not change in fenced soils. Grazing played a key role in determining the community structure of soil cellulolytic fungi by explaining 8.1% of the variation, while pH and DOC explained 4.1% and 4.0%, respectively. Phylogenetically, the cellulolytic fungi were primarily affiliated with Ascomycota (69.65% in relative abundance) and Basidiomycota (30.35%). Therefore, grazing substantially reduced the stability of soil cellulolytic fungal abundance and community structure, as compared with the fencing treatment. Our finding provides a new insight into the responses of organic matter-decomposing microbes for grassland managements.

Explaining regional variations in colon cancer survival in Ontario, Canada: a population-based retrospective cohort study

OBJECTIVES

Regional variation in cancer survival is an important health system performance measurement. We evaluated if regional variation in colon cancer survival may be driven by differences in the patient population, their health and healthcare utilisation, and/or cancer care delivery.

DESIGN

Population-based retrospective cohort study using routinely collected linked health administrative data.

SETTING

Ontario, Canada.

PARTICIPANTS

Patients with colon cancer diagnosed between 1 January 2009 and 31 December 2012.

OUTCOME

Cancer-specific survival was compared across the province's 14 health regions. Using accelerated failure time models, we assessed whether regional survival variations were mediated through differences in case mix, including age, sex, comorbidities, stage at diagnosis and colon subsite, potential marginalisation and/or prediagnosis healthcare.

RESULTS

The study population included 16 895 patients with colon cancer. There was statistically significant regional variation in cancer-specific survival. Three regions had cancer-specific survival that was between 30% (95% CI 1.03 to 1.65) and 39% (95% CI 1.13 to 1.71) longer and one region had cancer-specific survival that was 26% shorter (95% CI 0.58 to 0.93) than the reference region. For three of these regions, case mix explained between 26% and 56% of the survival variation. Further adjustment for rurality explained 22% of the remaining survival variation in one region. Adjustment for continuity of primary care and the diagnostic interval length explained 10% and 11% of the remaining survival variation in two other regions. Socioeconomic marginalisation, recent immigration and colonoscopy history did not explain colon cancer survival variation.

CONCLUSIONS

Case mix accounted for much of the regional variation in colon cancer survival, indicating that efforts to monitor the quality of cancer care through survival metrics should consider case mix when reporting regional survival differences. Future work should repeat this approach in other settings and other cancer sites considering a broad range of potential mediators.

Atmospheric chemosynthesis is phylogenetically and geographically widespread and contributes significantly to carbon fixation throughout cold deserts

Cold desert soil microbiomes thrive despite severe moisture and nutrient limitations. In Eastern Antarctic soils, bacterial primary production is supported by trace gas oxidation and the light-independent RuBisCO form IE. This study aims to determine if atmospheric chemosynthesis is widespread within Antarctic, Arctic and Tibetan cold deserts, to identify the breadth of trace gas chemosynthetic taxa and to further characterize the genetic determinants of this process. H₂ oxidation was ubiquitous, far exceeding rates reported to fulfill the maintenance needs of similarly structured edaphic microbiomes. Atmospheric chemosynthesis occurred globally, contributing significantly (p < 0.05) to carbon fixation in Antarctica and the high Arctic. Taxonomic and functional analyses were performed upon 18 cold desert metagenomes, 230 dereplicated medium-to-high-quality derived metagenome-assembled genomes (MAGs) and an additional 24,080 publicly available genomes. Hydrogenotrophic and carboxydotrophic growth markers were widespread. RuBisCO IE was discovered to co-occur alongside trace gas oxidation enzymes in representative Chloroflexota, Firmicutes, Deinococcota and Verrucomicrobiota genomes. We identify a novel group of high-affinity [NiFe]-hydrogenases, group 1m, through phylogenetics, gene structure analysis and homology modeling, and reveal substantial genetic diversity within RuBisCO form IE (rbcL1E), and high-affinity 1h and 1l [NiFe]-hydrogenase groups. We conclude that atmospheric chemosynthesis is a globally-distributed phenomenon, extending throughout cold deserts, with significant implications for the global carbon cycle and bacterial survival within environmental reservoirs.

Transcriptome analysis of gene expression in the tomato leaf premature senescence mutant

Premature senescence of leaves can critically influence tomato yield and quality. In this study, the leaf premature senescence mutant MT318 was a spontaneous mutant and was controlled by a single recessive nuclear gene. The maximum photochemical efficiency (Fv/Fm), superoxide dismutase (SOD), and chlorophyll content in the leaves of mutant MT318 gradually decreased, while malondialdehyde (MDA) content significantly increased. Under the level 2 category, Gene Ontology (GO) enrichment analysis indicated that 45 terms were enriched, comprising 22 in biological process, 12 in cellular component, and 11 in molecular function. Genes are mainly involved in the metabolic processes (696 differentially expressed genes, DEGs), cellular processes (573 DEGs), single-organism processes (503 DEGs), and catalytic activity (675 DEGs). Kyoto Encyclopedia of Genes and Genomes pathway analysis demonstrated that the 4 pathways with the largest number of genes were biosynthesis of secondary metabolites, plant-pathogen interaction, plant hormone signal transduction, and MAPK signaling pathway-plant. The 'plant hormone signal transduction' pathway was the most significantly enriched at the T2 stage. Pearson correlation analysis showed that the auxin regulatory pathway and SA signal transduction pathway may play important roles. These results not only lay the foundation for the further cloning and functional analysis of the MT318 premature senescence gene but also provide a reference for the study of tomato leaf senescence.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s12298-022-01223-2.

Real-world outcomes associated with bevacizumab combined with chemotherapy in platinum-resistant ovarian cancer

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Background: In the pivotal Aurelia study, addition of bevacizumab (bev) to physician’s choice chemotherapy (paclitaxel, liposomal doxorubicin or topotecan) for platinum-resistant (PL-R) ovarian cancer (OC) was associated with improved progression-free survival (PFS; 6.7 vs 3.4 mos; hazard ratio (HR) 0.48, p = 0.001) but not overall survival (OS; 16.6 vs 13.3 mos HR 0.85, p = 0.174); the latter finding may relate to extensive crossover. In an exploratory subgroup analysis by treatment arm, benefits were particularly marked for bev + paclitaxel where median PFS (mPFS) increased from 3.9 to 10.4 mos (HR 0.46; 95%CI 0.30-0.71) and increases in OS approached statistical significance (HR 0.65; 95%CI, 0.42-1.02; 22.4 v 13.2 mos). Here we describe utilization of bev for PL-R OC and outcomes in routine clinical practice. Methods: The Ontario Cancer Registry and the New Drug Funding Program databases were utilized to identify all patients treated with bev plus chemotherapy (paclitaxel, liposomal doxorubicin or topotecan) for PL-R OC following its approval in 2017. Time on treatment (ToT) was defined as time from first to last bev treatment; this was used as a surrogate for PFS in routine practice. Median OS (mOS) was determined using the Kaplan-Meier method. Factors associated with ToT and OS were identified using a Cox proportional hazard model. A before and after comparison analysis was performed to determine mOS for patients treated pre- (2011-2017) and post-bev (2017-2019) approval. Results: From Oct 2017 to Dec 2019, 180 patients received bev + chemotherapy for first-line PL-R OC. Mean age was 63 years old, and 80% had serous OC. Bev was most often combined with liposomal doxorubicin (64 %) followed by paclitaxel (34%) and topotecan (2%). Median ToT was 3 months and OS was 11 months. ToT and OS were longer in patients who received paclitaxel as chemotherapy backbone (5 mos [ToT]; 14 mos [OS]) than those who received bev with liposomal doxorubicin (2 mos; 9 mos) or topotecan (2 mos; 6 mos). In multivariable models, ToT was superior in patients who received bev + paclitaxel than bev + liposomal doxorubicin (HR 0.40; 95%CI 0.28-0.57; p < 0.0001), and worse with longer time from diagnosis to bev start (1.03; 1.01-1.05; p = 0.0120). OS was also significantly longer in those who received paclitaxel vs liposomal doxorubicin (HR 0.54; 95%CI 0.30-0.98; p = 0.043). In a before and after analysis, patients treated in the pre- (n = 1290) and post-bev (n = 360) era had mOS of 8 and 9 months respectively. Post mOS increased for patients receiving paclitaxel (7 vs 12 months) but not with liposomal doxorubicin (9 vs 7 months). Conclusions: ToT and OS associated with bev for PL-R OC are shorter in a real-world population compared to results reported in AURELIA. ToT and OS were longer with bev + paclitaxel than with other chemotherapy agents.

Incidence, Timing, and Outcomes of Venous Thromboembolism in Patients Undergoing Surgery for Esophagogastric Cancer: A Population-Based Cohort Study

BACKGROUND

Abdominal surgery and chemotherapy are well-established risk factors for venous thromboembolism (VTE) in patients with cancer, but their specific contribution in patients with esophageal and gastric cancer is unclear. We aim to quantify the risk of VTE, identify risk factors associated with VTE, and determine the association between VTE and survival in patients undergoing surgery for esophageal or gastric cancer.

METHODS

A retrospective, population-based cohort study was conducted using linked administrative healthcare databases. We used the Ontario Cancer Registry to identify patients with esophageal or gastric cancer between January 1, 2007 and December 31, 2016 who underwent surgical resection. Incidence of first VTE event was identified using International Classification of Diseases 9 and 10 codes. VTE incidence was calculated at clinically relevant time points 180 days before and after surgery. Logistic regression was used to identify factors associated with VTE with odds ratios (OR) and 95% confidence intervals (CI) reported. Cox proportional hazards regression models were used to estimate associations between covariates and survival. Kaplan-Meier method was used to compare overall (OS) and cancer-specific survival (CSS) by VTE status.

RESULTS

A total of 4894 patients had esophagectomy or gastrectomy, of which 8% (n = 383/4894) had VTE. VTE risk was 2.5% (n = 123/4894) 180 days before surgery, 2.8% (n = 138/4894) within 30 days of surgery, and 2.5% (n = 122/4894) from 31 to ≤ 180 days after surgery. Of the patients with VTE within 30 days of surgery, 34% (n = 47/138) were diagnosed after discharge from hospital. Receipt of preoperative chemotherapy was associated with VTE 180 days before surgery (odds ratio [OR] 3.84, 95% confidence interval [CI] 2.41, 6.11). Increased hospital length of stay (LOS) was associated with VTE 30 days after surgery (OR 1.08, 95% CI 1.02, 1.14, per week). Patients with VTE had inferior median OS and CSS (2.2 vs. 3.7 years; 2.3 vs. 4.4 years, respectively). In adjusted models VTE was associated with inferior OS (HR 1.36, 95% CI 1.13, 1.63) and CSS (HR 1.42, 95% CI 1.16, 1.75).

CONCLUSIONS

The highest risk of VTE is within 30 days of surgery with one third of patients diagnosed after discharge from hospital. Longer hospital LOS and receipt of preoperative chemotherapy are associated with increased risk of VTE. VTE is an independent risk factor for inferior survival in patients with esophageal or gastric cancer.

Similar heterotrophic communities but distinct interactions supported by red and green-snow algae in the Antarctic Peninsula

Snow algae are predicted to expand in polar regions due to climate warming, which can accelerate snowmelt by reducing albedo. Green snow frequently occurs near penguin colonies, and red snow distributes widely along ocean shores. However, the mechanisms underpinning the assemblage of algae and heterotrophs in colored snow remain poorly characterized. We investigated algal, bacterial, and fungal communities and their interactions in red and green snows in the Antarctic Peninsula using a high-throughput sequencing method. We found distinct algal community structure in red and green snows, and the relative abundance of dominant taxa varied, potentially due to nutrient status differences. Contrastingly, red and green snows exhibited similar heterotrophic communities (bacteria and fungi), whereas the relative abundance of fungal pathogens was substantially higher in red snow by 3.8-fold. Red snow exhibited a higher network complexity, indicated by a higher number of nodes and edges. Red snow exhibited a higher proportion of negative correlations among heterotrophs (62.2% vs 3.4%) and stronger network stability, suggesting the red-snow network is more resistant to external disturbance. Our study revealed that the red snow microbiome exhibits a more stable microbial network than the green snow microbiome.

Prokaryotic Community Succession in Bulk and Rhizosphere Soils Along a High-Elevation Glacier Retreat Chronosequence on the Tibetan Plateau

Early colonization and succession of soil microbial communities are essential for soil development and nutrient accumulation. Herein we focused on the changes in pioneer prokaryotic communities in rhizosphere and bulk soils along the high-elevation glacier retreat chronosequence, the northern Himalayas, Tibetan Plateau. Rhizosphere soils showed substantially higher levels of total organic carbon, total nitrogen, ammonium, and nitrate than bulk soils. The dominant prokaryotes were Proteobacteria, Actinobacteria, Acidobacteria, Chloroflexi, Crenarchaeota, Bacteroidetes, and Planctomycetes, which totally accounted for more than 75% in relative abundance. The dominant genus Candidatus Nitrososphaera occurred at each stage of the microbial succession. The richness and evenness of soil prokaryotes displayed mild succession along chronosequene. Linear discriminant analysis effect size (LEfSe) analysis demonstrated that Proteobacteria (especially Alphaproteobacteria) and Actinobacteria were significantly enriched in rhizosphere soils compared with bulk soils. Actinobacteria, SHA_109, and Thermoleophilia; Betaproteobacteria and OP1.MSBL6; and Planctomycetia and Verrucomicrobia were separately enriched at each of the three sample sites. The compositions of prokaryotic communities were substantially changed with bulk and rhizosphere soils and sampling sites, indicating that the communities were dominantly driven by plants and habitat-specific effects in the deglaciated soils. Additionally, the distance to the glacier terminus also played a significant role in driving the change of prokaryotic communities in both bulk and rhizosphere soils. Soil C/N ratio exhibited a greater effect on prokaryotic communities in bulk soils than rhizosphere soils. These results indicate that plants, habitat, and glacier retreat chronosequence collectively control prokaryotic community composition and succession.

Microbial anhydrobiosis

The loss of cellular water (desiccation) and the resulting low cytosolic water activity are major stress factors for life. Numerous prokaryotic and eukaryotic taxa have evolved molecular and physiological adaptions to periods of low water availability or water-limited environments that occur across the terrestrial Earth. The changes within cells during the processes of desiccation and rehydration, from the activation (and inactivation) of biosynthetic pathways to the accumulation of compatible solutes, have been studied in considerable detail. However, relatively little is known on the metabolic status of organisms in the desiccated state; that is, in the sometimes extended periods between the drying and rewetting phases. During these periods, which can extend beyond decades and which we term 'anhydrobiosis', organismal survival could be dependent on a continued supply of energy to maintain the basal metabolic processes necessary for critical functions such as macromolecular repair. Here, we review the state of knowledge relating to the function of microorganisms during the anhydrobiotic state, highlighting substantial gaps in our understanding of qualitative and quantitative aspects of molecular and biochemical processes in desiccated cells.

Practice Patterns and Outcomes of Novel Targeted Agents for the Treatment of ERBB2-Positive Metastatic Breast Cancer

Importance

Clinical trials have shown that the addition of pertuzumab to trastuzumab-based chemotherapy for first-line treatment of ERBB2-positive metastatic breast cancer is associated with considerable improvement in overall survival (OS). In the second-line setting, trastuzumab emtansine (T-DM1) improves OS compared with capecitabine/lapatinib in patients previously treated with trastuzumab-based chemotherapy. However, there are few data describing long-term real-world outcomes with these agents.

Objective

To describe practice patterns and outcomes associated with pertuzumab and T-DM1 in routine clinical practice.

Design, Setting, and Participants

This population-based retrospective cohort study used the Ontario Cancer Registry linked to electronic treatment databases to identify all patients treated with pertuzumab and T-DM1 following reimbursement approval in Ontario, Canada, which has a single-payer public health system. Participants included women with stage IV ERBB2-positive metastatic breast cancer receiving treatment with pertuzumab for first-line metastatic indication from December 2013 through December 2017, and those treated with T-DM1 from May 2014 through December 2017. Pertuzumab and T-DM1 cohorts were analyzed separately. Data were analyzed December 2019 to December 2020.

Exposures

Treatment with pertuzumab or T-DM1.

Main Outcomes and Measures

The primary outcome was OS, determined using the Kaplan-Meier method. Factors associated with OS were identified using a Cox proportional hazard model.

Results

The median (interquartile range [IQR]) age of the 795 women who received pertuzumab and 506 women who received T-DM1 was 57 (49-67) and 56 (48-66) years, respectively. Among the entire population, the median (IQR) OS and time on treatment was 43 (16.2-unavailable) and 14 (6.0-26.2) months, respectively. In the T-DM1 cohort, the proportion of pertuzumab-naive patients decreased over time from 68 of 91 [74.7%] in 2014 to 16 of 89 [18.0%] in 2017 (P < .001). The median (IQR) OS and time on treatment was 15 (6.7-27.7) and 4 (1.4-9.0) months, respectively. Median OS was shorter for patients with prior pertuzumab treatment than in the pertuzumab-naive subgroup (12 vs 19 months; adjusted hazard ratio, 0.70; 95% CI, 0.55-0.89; P = .004).

Conclusions and Relevance

In this population-based cohort study, the survival of patients treated with pertuzumab and T-DM1 in routine practice appeared inferior to results from pivotal clinical trials. Differences in outcome likely reflect differences in patient population and previous lines of therapy in routine practice. Further work is needed to understand the effectiveness of T-DM1 after pertuzumab exposure.

Inverse hydrogen isotope fractionation indicates heterotrophic microbial production of long-chain n-alkyl lipids in desolate Antarctic ponds

Long-chain (>C₂₅ ) n-alkyl lipids have long been considered biomarkers for higher plant leaf waxes and widely applied for paleoclimate and paleoenvironmental reconstructions. However, recent experimental and lacustrine sediment studies suggest long-chain n-alkanes and n-alkanoic acids can also be produced by aerobic microbes, probably heterotrophic microbes based on carbon isotope data. Here we show that sedimentary long-chain n-alkanes and n-alkanoic acids in two desolate Antarctic ponds where vascular plants are absent in the surroundings display hydrogen isotopic values up to 300 per mil higher than those of lake water. It is the first time that such strongly inverse or reduced hydrogen isotopic fractionation of lipid biomarkers is observed in natural sediment samples. Based on recent extensive experimental data on microbial hydrogen isotopic fractionation, our data can only be explained by the predominant production of long-chain n-alkanes and n-alkanoic acids from heterotrophic micro-organisms. Together with preliminary 16S rRNA gene sequencing data, our results represent the first unambiguous example of predominant heterotrophic microbial production of long-chain n-alkyl waxes in a natural environment.

The contrasting effects of biochar and straw on N2O emissions in the maize season in intensively farmed soil

This study evaluated the combined effects of biochar and straw on N2O flux and the community compositions of nitrifiers and denitrifiers in the maize season in an intensively farmed area in northern China. The experiment consisted of four treatments: (1) CK (only chemical fertilizer application); (2) C (biochar application); (3) SR (straw application to the field); and (4) C+SR (the application of both biochar and straw). The results indicated that during the maize growing season, N2O flux decreased by 30.3% in the C treatment and increased by 13.2% and 37.0% in the SR and C+SR treatments compared with CK, respectively. NO3--N, NH4+-N, and microbial biomass carbon (MBC) were the main soil factors affecting N2O flux, and they were positively correlated with NO3--N and negatively correlated with MBC in the C treatment and positively correlated with NH4+-N in the SR and C+SR treatments. Both biochar addition and straw return shifted the community compositions of nitrifiers and denitrifiers. N2O production was mainly reduced by promoting the ammonia-oxidizing bacteria (AOB) gene abundance and inhibiting the nirK gene abundance in the C treatment but promoted by inhibiting the AOB and nosZ gene abundances in the SR and C+SR treatments. Nitrosospira (AOB) and Rhizobium (nirK) were the main contributors among the treatments. NO3--N, NH4+-N, and MBC were the main soil factors affecting the denitrifier communities. The predominant species associated with the nirK, nirS, and nosZ genes were positively correlated with NO3--N and MBC and negatively correlated with NH4+-N. These results provide valuable information on the mechanism of N2O production and reduction in biochar- and straw-amended soil under field conditions.

Dissolved inorganic carbon determines the abundance of microbial primary producers and primary production in Tibetan Plateau lakes

Climate change globally accelerates the shrinkage of inland lakes, resulting in increases in both water salinity and dissolved inorganic carbon (DIC). The increases of salinity and DIC generate contrasting effects on microbial primary producers and primary production, however, their combined effects remain unclear in aquatic ecosystems. We hypothesized that increased DIC mitigates the constraints of enhanced salinity on microbial primary producers and primary production. To test this, we employed isotope labeling and molecular methods to explore primary production and four dominant types of microbial primary producers (form IA, IB, IC and ID) in lakes on the Tibetan Plateau. Results showed that DIC was positively correlated with the abundance of the form IAB and ID microbial primary producers and primary production (all P < 0.001) and offset salinity constraints. Structural equation models elucidated that DIC substantially enhanced primary production by stimulating the abundance of form ID microbial primary producers. The abundance of form ID primary producers explained more variations (14.6%) of primary production than form IAB (6%) and physicochemical factors (6.8%). Diatoms (form ID) played a determinant role in primary production in the lakes by adapting to high DIC and high salinity. Our findings suggest that inland lakes may support higher primary productivity in future climate change scenarios.

Soil microbial CO2 fixation plays a significant role in terrestrial carbon sink in a dryland ecosystem: A four-year small-scale field-plot observation on the Tibetan Plateau

Assessment of the global terrestrial carbon (C) sink remains uncertain, and the uncertainty is largely derived from dryland ecosystems. Here we investigated the uncertainty and dynamics of gross primary productivity (GPP) by distinguishing the contributions of soil microbial primary producers and plants to CO₂ fixation during four sequential growing seasons in a fragile dry grassland on the Tibetan Plateau. The results demonstrated that soil microbial GPP consistently accounted for a high proportion of plant GPP (18.2%), and both exhibited similar seasonal patterns during the four-year observation. Soil microbial GPP demonstrated a much greater interannual variation (76.1%) than plant GPP (15.1%), indicating that the interannual GPP uncertainty could be largely from microbial primary producers. Regression analysis indicated that plant GPP had higher sensitivity (demonstrated by slope) than soil microbial GPP to both soil water content and temperature. The GPP ratio of soil microbes to plants also demonstrated a clear seasonal change, and peaked in July in the four-year observation, with a minimum interannual variation (6.8%). The GPP ratio enhanced with increasing soil water content (P < 0.001), but did not correlate with soil temperature. Our findings suggest the great potential of soil microbial GPP, and challenge the plant-oriented models of terrestrial C estimation, which account for plant GPP but ignore soil microbial GPP. Thus, a more robust framework needs to incorporate both soil microbial and plant GPPs for accurately assessing C balance.

First-Line Palliative Chemotherapy for Esophageal and Gastric Cancer: Practice Patterns and Outcomes in the General Population

PURPOSE

Clinical trials have shown that palliative chemotherapy (PC) improves survival in patients with incurable esophageal and gastric cancer; however, outcomes achieved in routine practice are unknown. We describe treatment patterns and outcomes among patients treated in the general population of Ontario, Canada.

METHODS

The Ontario Cancer Registry was used to identify patients with esophageal or gastric cancer from 2007 to 2016, and data were linked to other health administrative databases. Patients who received curative-intent surgery or radiotherapy were excluded. Factors associated with the receipt of PC were determined using logistic regression. First-line PC regimens were categorized, and trends over time were reported. Survival was determined using the Kaplan-Meier method.

RESULTS

The cohort included 9,848 patients; 22% (2,207 of 9,848) received PC. Patients receiving PC were younger (mean age, 63 v 74 years; P < .0001) and more likely male (71% v 65%; P < .0001). Thirty-seven percent of non-PC patients saw a medical oncologist in consultation. Over the study period, utilization of PC increased (from 11% in 2007 to 19% in 2016; P < .0001), whereas the proportion of patients receiving triplet regimens decreased (65% in 2007 to 56% in 2016; P = .04). In the PC group, the median overall and cancer-specific survival from treatment initiation was 7.2 months.

CONCLUSION

One fifth of patients with incurable esophageal and gastric cancer in the general population receive PC. Median survival of patients treated in routine practice is inferior to that in clinical trials. Only one third of patients not treated with PC had consultation with a medical oncologist. Further work is necessary to understand low utilization of PC and medical oncology consultation in this patient population.

Combined T2 SPAIR, Dynamic Enhancement and DW Imaging Reliably Detect T Staging and Grading of Bladder Cancer With 3.0T MRI

Objectives

To evaluate bladder cancer by integrating multiple imaging features acquired using multimodal 3.0T magnetic resonance imaging (MRI).

Methods

We prospectively enrolled 163 consecutive patients including 142 men (mean age, 65.2 years) and 21 women (mean age, 65.8 years). We evaluated the efficiency and reliability of the multiple imaging modalities including T2-weighted spectral attenuated inversion recovery (SPAIR) imaging, dynamic contrast-enhanced (DCE) imaging and diffusion-weighted (DW) imaging, and the imaging feature, apparent diffusion coefficient (ADC) in the identification of the T staging and grading. We compared our imaging findings with the results of histological examination using McNemar’s test. We reported the results under the significance of p < 0.05. Approval for the study was obtained from the local institutional review board.

Results

The sensitivity and specificity using T2 SPAIR plus DW imaging (sensitivity: 85.2%; specificity: 93.2%), DCE plus DW imaging (sensitivity: 92.4%; specificity: 96.8%), and all the three imaging modalities combined, i.e., T2 SPAIR plus DCE plus DW imaging (sensitivity: 92.5%; specificity: 97.4%), were significantly greater than using T2 SPAIR imaging alone (sensitivity: 74.1%; specificity: 72.2%). One hundred six (93.0%) lesions showed a thin, pedicle arch-like shape and thus primarily demonstrated to be in Ta stage; by contrast, a large number of lesions (137 [85.6%]) were sessile and were found to be in T1 stage. The differences in the ADC were significant between low-grade (877.57 ± 24.15) and high-grade (699.54 ± 23.82) lesions (P < .01).

Conclusions

T2 SPAIR and DCE plus DW imaging provided useful information for evaluating T staging and grading in bladder cancer. Those imaging features to distinguish Ta stage from T1 stage were presented.

Symptom Evolution in Patients with Esophageal and Gastric Cancer Receiving Palliative Chemotherapy: A Population-Based Study

INTRODUCTION

Palliative chemotherapy (PC) is associated with a modest survival benefit in patients with incurable esophageal and gastric cancer; however, changes in symptom profile during treatment are not well described. Understanding the trajectory of symptoms during treatment may lead to improved care and facilitate shared decision making. In this study, we address this knowledge gap among all patients receiving PC in the Canadian province of Ontario.

METHODS

Patients diagnosed with incurable esophageal and gastric cancer who received PC from 2012 to 2017 were identified from the Ontario Cancer Registry. Patients with one or more recorded Edmonton Symptom Assessment System (ESAS) scores in the 12 months following cancer diagnosis were included. The ESAS includes scores from 0 to 10 in nine domains (anxiety, depression, drowsiness, lack of appetite, nausea, pain, shortness of breath, tiredness, and lack of well-being). Symptom severity is categorized as none-mild (≤ 3), moderate (4-6), or severe (7-10). We focused on potentially modifiable symptoms, i.e. nausea, pain, and anxiety/depression. Logistic regression was used to identify factors associated with moderate-severe ESAS scores in these domains. Among those patients with serial ESAS scores (at 8 ± 2 and 12 ± 2 weeks) receiving chemotherapy, we describe changes during treatment (decrease by ≥ 1 = improved; - 1 > 0 > 1 = unchanged; increase by ≥ 1 = deteriorated).

RESULTS

The cohort included 1900 patients who received PC, of whom 79% (1497/1900) had one or more recorded ESAS scores. In multivariate analysis, younger patients were more likely to have moderate-severe scores in nausea (odds ratio [OR] 1.89, 95% confidence interval [CI] 1.23-2.90 [p < 0.01] in patients aged 41-50 years compared with patients aged ≥ 71 years) and pain (OR 1.88, 95% CI 1.36-2.60 [p < 0.01] in patients aged 51-60 years compared with patients aged ≥ 71 years). Compared with males, females were more likely to report moderate-severe scores in anxiety/depression (OR 1.58, 95% CI 1.21-2.08 [p < 0.01]). At 8 ± 2 weeks from PC initiation, symptom scores were unchanged in 19-42% of patients, improved in 30-51% of patients, and deteriorated in 17-35% of patients. The greatest change in symptom burden was observed for appetite (51% improvement) and anxiety/depression (35% deterioration). Similar trends were observed at 12 ± 2 weeks.

CONCLUSIONS

In this large, population-based study, we observed that younger patients were more likely to report moderate-severe symptoms in pain and nausea, and females were more likely to report moderate-severe symptoms in anxiety/depression. Anxiety/depression symptoms become increasingly problematic for a substantial proportion of patients receiving PC. Supportive care efforts to mitigate these symptoms in routine practice are needed.

The efficacy and safety of Chinese herbal compound or combined with western medicine for pediatric adenoidal hypertrophy: A protocol for systematic review and meta-analysis

BACKGROUND

Traditional Chinese medicine (TCM) or combined with western medicine in the treatment of pediatric adenoidal hypertrophy has been widely used in clinical practice, but the overall efficacy and safety is still unclear. This paper aims to evaluate the efficacy and safety analysis of TCM or combined with western medicine for pediatric adenoidal hypertrophy.

METHODS

PubMed, EMbase, Cochrane Library, Web of Science, China National Knowledge Infrastructure (CNKI), WanFang, the Chongqing VIP Chinese Science and Technology Periodical Database, and China biomedical literature database (CBM) were searched for randomized controlled trials of TCM or combined with western medicine for pediatric adenoidal hypertrophy from the date of establishment to July 2020, and Baidu Scholar, Google Scholar, International Clinical Trials Registry Platform (ICTRP), and Chinese Clinical Trials Registry (ChiCTR) were searched for unpublished grey literature. Two researchers independently applied RevMan 5.3 software for data extraction and risk assessment of bias.

RESULTS

The effectiveness and safety of TCM or combined with western medicine for pediatric adenoidal hypertrophy is evaluated by means of the Adenoid (A) /(Nasopharyngeal (N) ratio, clinical efficacy, integral score of TCM syndromes, clinical single symptom score, disease specific quality of life for children with obstructive sleep apnea 18 items survey (OSA-18), Interleukin 4 (IL-4) and adverse reaction incidence.

CONCLUSION

This study will provide theoretical support for the clinical application of TCM or combined with western medicine for pediatric adenoidal hypertrophy.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/J76AG.

Soil Microbiomes With the Genetic Capacity for Atmospheric Chemosynthesis Are Widespread Across the Poles and Are Associated With Moisture, Carbon, and Nitrogen Limitation

Soil microbiomes within oligotrophic cold deserts are extraordinarily diverse. Increasingly, oligotrophic sites with low levels of phototrophic primary producers are reported, leading researchers to question their carbon and energy sources. A novel microbial carbon fixation process termed atmospheric chemosynthesis recently filled this gap as it was shown to be supporting primary production at two Eastern Antarctic deserts. Atmospheric chemosynthesis uses energy liberated from the oxidation of atmospheric hydrogen to drive the Calvin-Benson-Bassham (CBB) cycle through a new chemotrophic form of ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO), designated IE. Here, we propose that the genetic determinants of this process; RuBisCO type IE (rbcL1E) and high affinity group 1h-[NiFe]-hydrogenase (hhyL) are widespread across cold desert soils and that this process is linked to dry and nutrient-poor environments. We used quantitative PCR (qPCR) to quantify these genes in 122 soil microbiomes across the three poles; spanning the Tibetan Plateau, 10 Antarctic and three high Arctic sites. Both genes were ubiquitous, being present at variable abundances in all 122 soils examined (rbcL1E, 6.25 × 10³–1.66 × 10⁹ copies/g soil; hhyL, 6.84 × 10³–5.07 × 10⁸ copies/g soil). For the Antarctic and Arctic sites, random forest and correlation analysis against 26 measured soil physicochemical parameters revealed that rbcL1E and hhyL genes were associated with lower soil moisture, carbon and nitrogen content. While further studies are required to quantify the rates of trace gas carbon fixation and the organisms involved, we highlight the global potential of desert soil microbiomes to be supported by this new minimalistic mode of carbon fixation, particularly throughout dry oligotrophic environments, which encompass more than 35% of the Earth’s surface.

Salinity reduces bacterial diversity, but increases network complexity in Tibetan Plateau lakes

Salinity is one of the most important environmental factors influencing bacterial plankton communities in lake waters, while its influence on bacterial interactions has been less explored. Here, we investigated the influence of salinity on the bacterial diversity, interactions and community structure in Tibetan Plateau lakes. Our results revealed that saline lakes (salinity between 0.5 and 50 g/L) harboured similar or even higher bacterial diversity compared with freshwater lakes (< 0.5 g/L), while hyper-saline lakes (> 50 g/L) exhibited the lowest diversity. Network analysis demonstrated that hyper-saline lakes exhibited the highest network complexity, with higher total correlation numbers (particularly the negative correlations), but lower network module numbers than freshwater and saline lakes. Furthermore, salinity dominantly explained the bacterial community structure variations in saline lakes, while those in freshwater and hyper-saline lakes were predominately explained by water temperature and geospatial distance, respectively. The core operational taxonomic units (OTUs), which were ubiquitously present in all lakes, were less sensitive to enhancing salinity than the indicative OTUs whose presence was dependent on lake type. Our findings offer a new understanding of how salinity influences bacterial community in plateau lakes.

Community response of microbial primary producers to salinity is primarily driven by nutrients in lakes

Higher microbial diversity was frequently observed in saline than fresh waters, but the underlying mechanisms remains unknown, particularly in microbial primary producers (MPP). MPP abundance and activity are notably constrained by high salinity, but facilitated by high nutrients. It remains to be ascertained whether and how nutrients regulate the salinity constraints on MPP abundance and community structure. Here we investigated the impact of nutrients on salinity constraints on MPP abundance and diversity in undisturbed lakes with a wide salinity range on the Tibetan Plateau. MPP community was explored using quantitative PCR, terminal restriction fragment length polymorphism and sequencing of cloning libraries targeting form IC cbbL gene. The MPP community structure was sorted by salinity into freshwater (salinity<1‰), saline (1‰ < salinity<29‰) and hypersaline (salinity>29‰) lakes. Furthermore, while MPP abundance, diversity and richness were significantly constrained with increasing salinity, these constraints were mitigated by enhancing total organic carbon (TOC) and total nitrogen (TN) contents in freshwater and saline lakes. In contrast, the MPP diversity increased significantly with the salinity in hypersaline lakes, due to the mitigation of enhancing TOC and TN contents and salt-tolerant MPP taxa. The mitigating effect of nutrients was more pronounced in saline than in freshwater and hypersaline lakes. The MPP compositions varied along salinity, with Betaproteobacteria dominating both the freshwater and saline lakes and Gammaproteobacteria dominating the hypersaline lakes. We concluded that high nutrients could mitigate the salinity constraining effects on MPP abundance, community richness and diversity. Our findings offer a novel insight into the salinity effects on primary producers and highlight the interactive effects of salinity and nutrients on MPP in lakes. These findings can be used as a baseline to illuminate the effects of increased anthropogenic activities altering nutrient dynamics on the global hydrological cycle and the subsequent responses thereof by MPP communities.

Contrasting environmental factors drive bacterial and eukaryotic community successions in freshly deglaciated soils

Glacier retreats expose deglaciated soils to microbial colonization and succession; however, the differences in drivers of bacterial and eukaryotic succession remain largely elusive. We explored soil bacterial and eukaryotic colonization and yearly community succession along a deglaciation chronosequence (10 years) on the Tibetan Plateau using qPCR, terminal restriction fragment length polymorphism (T-RFLP) and sequencing of clone libraries. The results exhibited that bacteria and eukaryotes rapidly colonized the soils in the first year of deglaciation, thereafter slowly increasing from 107 up to 1010 and 1011 gene copies g-1 soil, respectively. Bacterial and eukaryotic community changes were observed to group into distinct stages, including early (0-2 year old), transition (3-5 year old) and late stages (6-10 year old). Bacterial community succession was dominantly driven by soil factors (47.7%), among which soil moisture played a key role by explaining 26.9% of the variation. In contrast, eukaryotic community succession was dominantly driven by deglaciation age (22.2%). The dominant bacterial lineage was Cyanobacteria, which rapidly decreased from the early to the transition stage. Eukaryotes were dominated by glacier-originated Cercozoa in early stage soils, while green algae Chlorophyta substantially increased in late stage soils. Our findings revealed contrasting environmental factors driving bacterial and eukaryotic community successions.

The radiation dose tolerance of the brachial plexus: A systematic review and meta-analysis

PURPOSE

We performed a systematic review and meta-analysis of studies reporting the incidence of radiation induced brachial plexopathy (RIBP) and the associated radiotherapy doses to this structure.

METHODS

Databases were queried without language restriction for cohort studies reporting RIBP incidence and associated brachial plexus dose maximum dose (bpDmax). Studies specifying RIBP relative risk (RR) effect size were selected for meta-analysis. RRs for RIBP from each study were converted to a regression coefficient (β) and standard error corresponding to a continuous representation of bpDmax. The adjusted β from individual studies were combined using a random effects model and weighted by inverse variance (1/SE2). The trim and fill approach was used to assess publication bias.

RESULTS

We identified 25 studies that included 37 unique patient cohorts eligible for analysis. Seventeen cohorts experienced an RIBP incidence ≤5%, of which 6 cohorts exceeded conventional plexus constraints of 60 Gy for bpDmax. Five of the 6 cohorts were simulated with 3D-CT techniques. Meta-analysis of eligible studies demonstrated a significant increase in RIBP risk for each Gy increase in bpDmax (RR, 1.11; 95% CI 1.07-1.15). Results remained significant after adjustment for publication bias and when sensitivity analysis was performed.

CONCLUSIONS

Our results suggest that current brachial plexus constraints of 60-66 Gy are safe. Meta-analysis provides a log-linear model to quantify the association of brachial plexus dose and RIBP risk, and thus inform the therapeutic ratio for dose escalation. Further prospective studies reporting dosimetric data can better refine this model and inform brachial plexus constraint guidelines.

Using a combination of PLFA and DNA-based sequencing analyses to detect shifts in the soil microbial community composition after a simulated spring precipitation in a semi-arid grassland in China

Increased spring precipitation in semi-arid grasslands could improve annual primary productivity. However, little is known about the responses of soil microbes to individual spring precipitation. In this study, we combined phospholipid fatty acid (PLFA) and DNA-based high-throughput sequencing analyses to investigate short-term (days) shifts in the soil microbial community composition after a simulated spring precipitation. Under field conditions, the soils (approx. -0.3 MPa) were exposed to either a watering of 20 cm or natural drought, and soil samples were collected at days 1, 3, 5, 8, and 12 after watering. Soil labile organic carbon (C) and nitrogen (N) as well as microbial biomass C (MBC) were positively correlated with soil water content (SWC). Spring watering significantly increased plant phosphorus (P) uptake, but had no impact on soil available P (AP). Watering increased the PLFA biomarkers indicative for Gram-negative (G^-) bacteria and fungi. Two phyla of G^- bacteria, Proteobacteria and Bacteroidetes, as well as the fungal phylum Ascomycota were more abundant when SWC increased. In addition to SWC and its related environmental factors such as C and N availabilities, AP appeared to be an important factor in shaping the soil microbial community composition. The study highlights the combination use of the methods based on different microbial biomarkers (PLFA vs. DNA), and the results were in line with each other. While the PLFA-based method was more sensitive to short-term shifts in soil microbial community composition in response to a precipitation event, DNA-based method could provide more information on the microbial taxa at a finer taxonomic resolution. Our results provide methodological insights for future research on short-term response of soil microbial community to changing environmental conditions.

Evaluation and simulation of the impact of land use change on ecosystem services based on a carbon flow model: A case study of the Manas River Basin of Xinjiang, China

Land use change affects ecosystem services by changing the structure and function of ecosystems. Carbon flows throughout natural and socioeconomic systems can effectively reveal this process. The Manas River Basin has experienced rapid oasis expansion for decades, and land use change in the basin is very typical. Oasis expansion has caused a large amount of cropland to invade natural vegetation, thus affecting ecosystem services. This study used a biomass-based ecosystem service estimation model to assess changes in ecosystem services in the Manas River Basin. The carbon flow model was constructed using energy systems language, and the future development of ecosystem services was simulated based on different land use scenarios. The results show the following: (1) From 1980 to 2015, the river basin provisioning service was continuously optimized, while the regulating, supporting and cultural services were reduced. (2) If the expansion of cropland continues, then carbon will be transferred from the natural ecosystem to the cropland. Regulation, support and cultural services in the basin continue to decrease. Due to the shortage of water resources in the basin, the growth of provisioning services is limited. (3) If the project of returning cropland to grassland is implemented, then the carbon in the natural ecosystem will gradually recover. The regulating, supporting and cultural services of the river basin are rising, but provisioning services are gradually decreasing. In general, the model based on energy systems language can reflect the ecological process within the system and effectively reveal the carbon flow process between ecosystems. The use of carbon to quantify ecosystem services can harmonize dimensions, facilitate comparisons, and mitigate errors in outcomes due to different evaluation criteria or subjective factors. Therefore, this study combines energy systems language with carbon flow, which helps to more rationally explore the impact of land use change on ecosystem services, thereby providing valuable information for river basin management.

Cancer survival outcomes in Ontario, Canada: Significant unexplained variation

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Background: Cancer-specific outcomes are critical for assessing quality of care, and are key quality indicators for cancer control programs. Previous analyses of Ontario (Canada) data show that regional survival differences at the Local Health Integrated Network (LHIN) level exist for relative survival, overall survival, cancer-specific survival (CSS), and mortality rates.We sought to describe: 5-year cancer-specific survival (5Y-CSS) rates among Ontario LHINs; the impact of adjusting for known patient factors; and 5Y-CSS rates among patients diagnosed at Ontario's 50 largest cancer diagnosing hospitals. Methods: Newly diagnosed cases (colorectal, lung, breast, or prostate cancer) were identified in the Ontario Cancer Registry. Records were linked to data from CIHI and Statistics Canada, to identify date of diagnosis, cause-specific vital status, diagnosing hospital, and other reported variables. Cox regression models were used, and all models were adjusted for age and sex. Results: N = 498,382 incident cases (2007-2013) were included. 5Y-CSS varied across LHINs for all patients combined (range 62%-72%; p < 0.0001). Considering colorectal cancer cases as illustrative (N = 57,927), 5Y-CSS varied among LHINs from 58.4%-66.4% (p < 0.0001). Further adjusting for socioeconomic and urban-rural status minimally reduced that variation. Limiting the analysis cohort to patients diagnosed in one of Ontario's 50 largest hospitals (N = 43,245), 5Y-CSS ranged from 52% to 72% (p < 0.0001) among hospitals, and from 55% to 63% (p < 0.0001) among the hospitals affiliated with regional cancer centres. Comparable findings were seen for patients diagnosed with lung, breast, or prostate cancer. Collaborative staging data were available for a subset of patients; 5Y-CSS within all stage III patients (N = 5,360) ranged from 72% to 87%. Conclusions: Important, highly significant differences in cancer survival outcomes exist across Ontario. These are of great interest to patients, health-care providers, system administrators, and policy makers, and are not explained by adjusting for the variables included in these analyses.

Estimating the need for palliative radiotherapy for non-small cell lung cancer: A criterion-based benchmarking approach

BACKGROUND AND PURPOSE

Estimates of appropriate treatment rates are required for monitoring and improving access to cancer care. Optimal utilization rates for palliative radiotherapy (PRT) for patients with non-small cell lung cancer (NSCLC) remain undefined. We aim to estimate the appropriate PRT rate for the general NSCLC population.

MATERIALS AND METHODS

Ontario's population-based cancer registry identified patients with NSCLC who died of their disease between 2006 and 2010. Multivariate analysis identified factors affecting PRT use, enabling us to define a benchmark population with unimpeded access to PRT. Proportion of cases treated in the last 2 years of life (PRT_2y) was standardized to overall population characteristics. Benchmarks were compared to province-wide PRT_2y rates.

RESULTS

Availability of RT at the diagnosing hospital was the dominant determinant of increased PRT utilization. Patients diagnosed at hospitals with on site RT were therefore designated the benchmark population. The standardized benchmark for PRT_2y was 56%, compared to the province-wide rate of 49%. The gap between actual and optimal rates varied across patient ages, treatment indications, and geographic regions.

CONCLUSIONS

Approximately 56% of patients who die of NSCLC in Ontario need PRT, but many are never treated.

Elevational diversity and distribution of ammonia-oxidizing archaea community in meadow soils on the Tibetan Plateau

Unraveling elevational diversity patterns of plants and animals has long been attracting scientific interests. However, whether soil microorganisms exhibit similar elevational patterns remains largely less explored, especially for functional microbial communities, such as ammonia oxidizers. Here, we investigated the diversity and distribution pattern of ammonia-oxidizing archaea (AOA) in meadow soils along an elevation gradient from 4400 m to the grassline at 5100 m on the Tibetan Plateau using terminal restriction fragment length polymorphism (T-RFLP) and sequencing methods by targeting amoA gene. Increasing elevations led to lower soil temperature and pH, but higher nutrients and water content. The results showed that AOA diversity and evenness monotonically increased with elevation, while richness was relatively stable. The increase of diversity and evenness was attributed to the growth inhibition of warm-adapted AOA phylotypes by lower temperature and the growth facilitation of cold-adapted AOA phylotypes by richer nutrients at higher elevations. Low temperature thus played an important role in the AOA growth and niche separation. The AOA community variation was explained by the combined effect of all soil properties (32.6%), and 8.1% of the total variation was individually explained by soil pH. The total AOA abundance decreased, whereas soil potential nitrification rate (PNR) increased with increasing elevations. Soil PNR positively correlated with the abundance of cold-adapted AOA phylotypes. Our findings suggest that low temperature plays an important role in AOA elevational diversity pattern and niche separation, rising the negative effects of warming on AOA diversity and soil nitrification process in the Tibetan region.

Diversity and succession of autotrophic microbial community in high-elevation soils along deglaciation chronosequence

Global warming has resulted in substantial glacier retreats in high-elevation areas, exposing deglaciated soils to harsh environmental conditions. Autotrophic microbes are pioneering colonizers in the deglaciated soils and provide nutrients to the extreme ecosystem devoid of vegetation. However, autotrophic communities remain less studied in deglaciated soils. We explored the diversity and succession of the cbbL gene encoding the large subunit of form I RubisCO, a key CO2-fixing enzyme, using molecular methods in deglaciated soils along a 10-year deglaciation chronosequence on the Tibetan Plateau. Our results demonstrated that the abundance of all types of form I cbbL (IA/B, IC and ID) rapidly increased in young soils (0-2.5 years old) and kept stable in old soils. Soil total organic carbon (TOC) and total nitrogen (TN) gradually increased along the chronosequence and both demonstrated positive correlations with the abundance of bacteria and autotrophs, indicating that soil TOC and TN originated from autotrophs. Form IA/B autotrophs, affiliated with cyanobacteria, exhibited a substantially higher abundance than IC and ID. Cyanobacterial diversity and evenness increased in young soils (<6 years old) and then remained stable. Our findings suggest that cyabobacteria play an important role in accumulating TOC and TN in the deglaciated soils.