Mixed Individual-Aggregate Data on All-Cause Mortality in Bullous Pemphigoid: A Meta-analysis

Importance

The 1-year standardized mortality ratio (SMR) of bullous pemphigoid (BP) has been reported as 2.15 to 7.56 and lower in the US than in Europe.

Objective

To estimate the worldwide 1-year SMR of BP.

Data Sources

PubMed, Embase, Cochrane Library, Google Scholar, Lissa, and gray literature (eg, medRxiv) were screened for studies of BP published from inception to June 10, 2020, with review of reference lists.

Study Selection

Retrospective and prospective studies reporting 1-year all-cause mortality rate in patients with BP and providing age statistics (eg, mean [SD]).

Data Extraction and Synthesis

Two reviewers independently extracted the data. The 1-year SMR was computed in studies reporting 1-year mortality by combining information on age obtained from studies with aggregate data and individual data. Risk of representativity, misclassification, and attrition bias were assessed by a custom tool.

Main Outcomes and Measures

The primary end point was the worldwide 1-year SMR. Secondary analysis included comparison of 1-year SMRs between continents in a meta-regression.

Results

Three studies were performed in the US (n = 260), 1 in South America (n = 45), 16 in Asia (n = 1903), and 36 in Europe (n = 10 132) for a total of 56 unique studies and 12 340 unique patients included in the meta-analysis (mean [SD] age, 77.3 [12.7] years; 55.9% women). The mean (SD) patient age in the United States was 75.6 (13.7) years; in Asia, 73.8 (13.6) years; and in Europe, 78.1 (12.3) years. The worldwide 1-year SMR was estimated at 2.93 (95% CI, 2.59-3.28; I2 = 85.6%) for all 56 studies. The 1-year SMR in the US was 2.40 (95% CI, 0.89-3.90; I2 = 86.3%) for 3 studies; in Asia, 3.53 (95% CI, 2.85-4.20; I2 = 86.3%) for 16 studies; and in Europe, 2.77 (95% CI, 2.35-3.19; I2 = 86.3%) for 36 studies. After adjustment on the expected 1-year mortality rate, the European 1-year SMR did not differ significantly from the 1-year SMR in the United States (-0.48 vs Europe; 95% CI, -2.09 to 1.14; P = .56) and Asia (0.51 vs Europe; 95% CI, -0.56 to 1.58; P = .35). Risk of attrition bias was high (>10% censorship) in 16 studies (28.6%), low in 16 (28.6%), and unclear in 24 (42.9%). Only 4 studies (7.1%) had a sampling method guaranteeing the representativity of BP cases in a population.

Conclusions and Relevance

Although heterogeneity was high and overall quality of follow-up was poor, this meta-analysis confirms the high mortality rate among patients with BP.

Wooded Semi-Natural Habitats Complement Permanent Grasslands in Supporting Wild Bee Diversity in Agricultural Landscapes

Simple Summary

Loss of semi-natural habitats in agricultural landscapes negatively affects wild bees. These pollinators are, however, very important in agricultural landscapes as they enable the pollination of crops and wild plants. The aim of this study was thus to understand the respective roles of different wooded and herbaceous habitats in their ability to support a diversity of wild bees. We first found that wild bee communities differed between wooded and herbaceous habitats, some bee species being found in one type of habitat and not in the other. We also showed that wooded semi-natural habitats provide some species of pollen preferred by the bees. Finally, we found that in wooded habitats there are some interactions between plant and bee species that do not happen in permanent grasslands. However, the latter also plays an important role in the diversity of bees and plants, and these wooded and herbaceous habitats complement each other. Overall, our results underline the importance of maintaining a diversity of semi-natural habitats in agricultural landscapes to maintain a diversity of wild bees and thus promote the pollination of wild plants and crops.

Abstract

Loss of semi-natural habitats (SNH) in agricultural landscapes affects wild bees, often negatively. However, how bee communities respond varies and is still unclear. To date, few studies have used precise descriptors to understand these effects. Our aim was to understand the respective and complementary influences of different wooded and herbaceous habitats on wild bee communities. We selected thirty 500-m radius landscapes on a gradient of a percentage of wooded SNH in south-western France. At each landscape, we sampled wild bees in spring 2016 and plants in spring 2015 and 2016 at the forest edge, in a hedgerow, and in a permanent grassland. Pollen carried by the most abundant bee species was collected and identified. Using beta diversity indices, we showed that wild bee community composition differs between the three SNH types, and especially between herbaceous and wooded SNH. Based on Jacobs’ selection index, we showed that pollen of some plant species recorded in wooded SNH are preferentially selected by wild bees. Studying the impact of the loss of each SNH type on the global bee-pollen interaction network, we found that wooded SNH contributed to its resilience, enabling specific plant–bee interactions. Overall, our results underline the non-negligible contribution of wooded SNH to the diversity of wild bees in agricultural landscapes, and thus the importance of maintaining different types of SNH.

Identification of Somatic Mutations in Primary Cutaneous Diffuse Large B-Cell Lymphoma, Leg Type by Massive Parallel Sequencing

To determine whether the mutational profile of primary cutaneous diffuse large B-cell lymphoma, leg type (PCLBCL-LT) is unique by comparison with other diffuse large B-cell lymphoma subtypes, we analyzed a total cohort of 20 PCLBCL-LT patients by using next-generation sequencing with a lymphoma panel designed for diffuse large B-cell lymphoma. We also analyzed 12 pairs of tumor and control DNA samples by whole-exome sequencing, which led us to perform resequencing of three selected genes not included in the lymphoma panel: TBL1XR1, KLHL6, and IKZF3. Our study clearly identifies an original mutational landscape of PCLBCL-LT with a very restricted set of highly recurrent mutations (>40%) involving MYD88 (p.L265P variant), PIM1, and CD79B. Other genes involved in B-cell signaling, NF-κB activation, or DNA modeling were found altered, notably TBL1XR1 (33%), MYC (26%) CREBBP (26%), and IRF4 (21%) or HIST1H1E (41%). MYD88^L265P variant was associated with copy number variations or copy neutral loss of heterozygosity in 60% of patients. The most frequent genetic losses involved CDKN2A/2B, TNFAIP3/A20, PRDM1, TCF3, and CIITA. Together, these results show that PCLBCL-LT exhibits a unique mutational landscape, combining highly recurrent hotspot mutations in genes involved in NF-kB and B-cell signaling pathways, which provides a rationale for using selective inhibitors of the B-cell receptor.

The interplay of pollination, costs of reproduction and plant size in maternal fertility limitation in perennial Paeonia officinalis

Although several factors can limit female fertility in perennial plants, rarely have they been jointly studied in a single species over several years. In this study we experimentally manipulate seed production and simultaneously analyse the potential contribution of pollen limitation, costs of reproduction and plant size to variation in seed output over a 3-year period in the perennial herb Paeonia officinalis, in southern France. Since this rare species is threatened by forest closure in many sites we also examine the causes of female fertility variation in relation to habitat closure (open habitat vs. woodland). P. officinalis has a partial self-incompatibility system and only very low ability for autonomous self pollination in the absence of pollinators. However, supplementary pollination of individual plants in three consecutive years did not significantly increase seed production above natural levels. Forest closure was associated with a decline in ovule and seed production, which again was not due to pollen limitation since supplementary pollination had no significant effect on seed set in the woodland habitat. Comparison of the maternal fertility of plants which were previously excluded from reproduction with those which were hand pollinated to maximise seed set in two previous years produced no evidence that seed production in year three is limited by costs associated with prior reproduction. Likewise, flowering probability was not related to prior seed production but was however positively related to plant size. The absence of any influence of pollen limitation or prior reproduction on seed production suggests that sub-maximal seed production in long-lived perennial herbs may be part of a size-dependent strategy that maximises life-time seed production and fitness without compromising survival.

Low-cost diets: more energy, fewer nutrients

Energy-dense diets offer a low-cost dietary option to the consumer. However, they are more likely to be nutrient-poor. In this study, based on the French national food consumption survey, the diet costs were estimated using retail food prices in France. Adult participants were stratified by quartiles of energy cost (in euro/10 MJ). Dietary energy density, energy and nutrient intakes were then compared across groups. Participants in the lowest quartile of energy cost had the highest energy intakes, the most energy-dense diets and the lowest daily intakes of key vitamins and micronutrients. Participants in the highest quartile of energy cost had lower energy intakes, and diets that were higher in nutrients and lower in energy density. However, their daily diet costs were 165% higher. In this observational study, the more nutrient-dense diets were associated with higher diet costs.

Engineering of the pyruvate dehydrogenase bypass in Saccharomyces cerevisiae: role of the cytosolic Mg(2+) and mitochondrial K(+) acetaldehyde dehydrogenases Ald6p and Ald4p in acetate formation during alcoholic fermentation

Acetic acid plays a crucial role in the organoleptic balance of many fermented products. We have investigated the factors controlling the production of acetate by Saccharomyces cerevisiae during alcoholic fermentation by metabolic engineering of the enzymatic steps involved in its formation and its utilization. The impact of reduced pyruvate decarboxylase (PDC), limited acetaldehyde dehydrogenase (ACDH), or increased acetoacetyl coenzyme A synthetase (ACS) levels in a strain derived from a wine yeast strain was studied during alcoholic fermentation. In the strain with the PDC1 gene deleted exhibiting 25% of the PDC activity of the wild type, no significant differences were observed in the acetate yield or in the amounts of secondary metabolites formed. A strain overexpressing ACS2 and displaying a four- to sevenfold increase in ACS activity did not produce reduced acetate levels. In contrast, strains with one or two disrupted copies of ALD6, encoding the cytosolic Mg(2+)-activated NADP-dependent ACDH and exhibiting 60 and 30% of wild-type ACDH activity, showed a substantial decrease in acetate yield (the acetate production was 75 and 40% of wild-type production, respectively). This decrease was associated with a rerouting of carbon flux towards the formation of glycerol, succinate, and butanediol. The deletion of ALD4, encoding the mitochondrial K(+)-activated NAD(P)-linked ACDH, had no effect on the amount of acetate formed. In contrast, a strain lacking both Ald6p and Ald4p exhibited a long delay in growth and acetate production, suggesting that Ald4p can partially replace the Ald6p isoform. Moreover, the ald6 ald4 double mutant was still able to ferment large amounts of sugar and to produce acetate, suggesting the contribution of another member(s) of the ALD family.