Age affects drug survival rates of interleukin (IL)-17 and IL-23 inhibitors in patients with plaque psoriasis: Results from a retrospective, multicentric, multi-country, cohort study.

BACKGROUND: Scarce data related to the drug survival of biologic agents in psoriasis patients aged ≥65 years is available. OBJECTIVES: To evaluate the drug survival of interleukin (IL)-23 or the IL-17 inhibitors approved for the treatment of moderate-to-severe psoriasis in elderly patients (aged ≥65 years), compared with younger adult patients (aged <65 years), and to identify clinical predictors that can influence the drug survival. METHODS: This retrospective multicentric cohort study included adult patients with moderate-to-severe psoriasis, dissecting two-patient subcohorts based on age: elderly versus younger adults. Kaplan-Meier estimator and proportional hazard Cox regression models were used for drug survival analysis. RESULTS: We included 4178 patients and 4866 treatment courses; 934 were elderly (1072 treatment courses), and 3244 were younger patients (3794 treatment courses). Drug survival, considering all causes of interruption, was higher in patients aged <65 years than in elderly patients overall (log-rank p < 0.006). This difference was significant for treatment courses involving IL-23 inhibitors (p < 0.001) but not for those with IL-17 inhibitors (p = 0.2). According to both uni- and multi-variable models, elder age was associated with an increased risk of treatment discontinuation (univariable analysis: HR: 1.229, 95% CI 1.062-1.422; p < 0.006; multivariable analysis: HR: 1.199, 95% CI 1.010-1.422; p = 0.0377). Anti-IL-23 agents were associated with a reduced likelihood of treatment discontinuation after adjusting for other variables (HR: 0.520, 95% CI 0.368-0.735; p < 0.001). Being previously treated with IL-17 inhibitors increased the probability of discontinuation. CONCLUSION: Elderly patients with psoriasis have an increased risk of biologic treatment discontinuation compared with younger adult patients, particularly, if being treated with IL-23 inhibitors. However, in stratified analyses conducted in elderly patients, IL-23 inhibitors showed higher drug survival rates than IL-17 inhibitors.

Far-red light enrichment affects gene expression and architecture as well as growth and photosynthesis in rice.

Plants use light as a resource and signal. Photons within the 400-700 nm waveband are considered photosynthetically active. Far-red photons (FR, 700-800 nm) are used by plants to detect nearby vegetation and elicit the shade avoidance syndrome. In addition, FR photons have also been shown to contribute to photosynthesis, but knowledge about these dual effects remains scarce. Here, we study shoot-architectural and photosynthetic responses to supplemental FR light during the photoperiod in several rice varieties. We observed that FR enrichment only mildly affected the rice transcriptome and shoot architecture as compared to established model species, whereas leaf formation, tillering and biomass accumulation were clearly promoted. Consistent with this growth promotion, we found that CO2-fixation in supplemental FR was strongly enhanced, especially in plants acclimated to FR-enriched conditions as compared to control conditions. This growth promotion dominates the effects of FR photons on shoot development and architecture. When substituting FR enrichment with an end-of-day FR pulse, this prevented photosynthesis-promoting effects and elicited shade avoidance responses. We conclude that FR photons can have a dual role, where effects depend on the environmental context: in addition to being an environmental signal, they are also a potent source of harvestable energy.

Epidemiology of Pathogens Listed as Potential Bioterrorism Agents, the Netherlands, 2009‒2019.

We provide incidences (cases/10 million persons) in the Netherlands during 2009-2019 for pathogens listed as potential bioterrorism agents. We included pathogens from the highest categories of the European Medicines Agency or the US Centers for Disease Control and Prevention. Notifiable diseases and recently published data were used to calculate the average annual incidence. Coxiella burnetii had the highest incidence because of a Q fever epidemic during 2007-2010. Incidence then decreased to 10.8 cases/. Pathogens with an incidence >1 were Brucella spp. (2.5 cases), Francisella tularensis (1.3 cases), and Burkholderia pseudomallei (1.1 cases). Pathogens with an incidence <1 were hemorrhagic fever viruses (0.3 cases), Clostridium botulinum (0.2 cases), and Bacillus anthracis (0.1 cases). Variola major and Yersinia pestis were absent. The generally low incidences make it unlikely that ill-meaning persons can isolate these pathogens from natural sources in the Netherlands. However, the pathogens are stored in laboratories, underscoring the need for biosecurity measures.

Treatment of Severe Atopic Dermatitis with Dupilumab in Patients with Advanced Cancer.

Atopic dermatitis is a chronic inflammatory intensively pruritic skin disease. Patients with moderate-to-severe atopic dermatitis or with difficult-to-treat areas are candidates for systemic therapy, especially when topical therapy is inadequate. Currently, we have available not only conventional immunosuppressive systemic therapy, but also targeted biological therapy, which has shown a remarkable reduction in clinical severity with a good safety profile. Dupilumab has been approved to treat moderate-to-severe atopic dermatitis. Even though the therapy has been available for more than 3 years, there are still limited data regarding the treatment of patients with concomitant cancer. Previous immunosuppressive treatment for atopic dermatitis, such as cyclosporine or azathioprine, poses a safety risk for patients with malignant disease. We present a case series of three patients with advanced cancer and severe atopic dermatitis treated with dupilumab for an average of 17 months with a great response toward atopic dermatitis without cancer recurrence. One patient had colorectal cancer' the second and the third both had cancer duplicity-colorectal and kidney cancer and penile squamous cell carcinoma with prostate cancer. Our cases suggest that dupilumab can safely control atopic dermatitis in patients with advanced cancer.

Long-Term Efficacy, Safety, and Drug Survival of Guselkumab in Patients with Psoriasis: Real-World Data from the Czech Republic BIOREP Registry.

BACKGROUND: Real-world data on the long-term use of guselkumab for treatment of psoriasis are still limited. OBJECTIVE: We aimed to evaluate long-term efficacy, safety, and drug survival of guselkumab in a real-world setting. METHODS: This is a retrospective study analyzing Czech Republic registry (BIOREP) data of patients treated with guselkumab. RESULTS: In total, 333 patients were included. Improvement in Psoriasis Area and Severity Index (PASI) score was significant. Mean PASI score decreased from 16 at baseline to 0.7, 0.9, and 0.8 after 12, 24, and 36 months, respectively. Absolute PASI scores of ≤ 3 and ≤ 1 were achieved in 93.9% and 77.9%, 94.2% and 71.0%, and 94.8% and 70.7% of patients after 12, 24, and 36 months, respectively. Response PASI 90 and PASI 100 were attained in 81.8% and 57.1%, 75.4% and 50.7%, and 75.9% and 55.2% of patients after 12, 24, and 36 months, respectively. The percentage of patients achieving PASI 90 and PASI 100 responses was higher throughout the study in bio-naive and in normal-weight patients, while presence of psoriatic arthritis had no influence. Improvement in Dermatology Life Quality Index (DLQI) score was also significant; mean DLQI score decreased from 14.2 at baseline to 0.9, 1.0, and 0.7 after 12, 24, and 36 months, respectively. Patients with PASI 100 had lower mean DLQI throughout the study compared with patients with PASI 90. Major reason for discontinuation was loss of effectiveness in 7.1% of patients, while only 0.6% were due to adverse events. Overall cumulative drug survival was high, with only a minimal decline over time, reaching 91.6%, 87.0%, and 85.5% after 12, 24, and 36 months, respectively. Drug survival was not affected by previous biological treatment, patient weight, or presence of psoriatic arthritis. CONCLUSIONS: This real-world study demonstrated the long-term effectiveness, good safety profile, and high drug survival of guselkumab treatment over a period of 36 months.

Drug Survival of Interleukin (IL)­17 and IL­23 Inhibitors for the Treatment of Psoriasis: A Retrospective Multi­country, Multicentric Cohort Study.

BACKGROUND: Drug survival, defined as the length of time from initiation to discontinuation of a given therapy, allows comparisons between drugs, helps to predict patient's likelihood of remaining on a specific treatment, and achieving the best decision for each patient in daily clinical practice. OBJECTIVE: The aim of this study was to provide data on drug survival of secukinumab, ixekizumab, brodalumab, guselkumab, tildrakizumab, and risankizumab in a large international cohort, and to identify clinical predictors that might have an impact on the drug survival of these drugs. METHODS: This was a retrospective, multicentric, multi-country study that provides data of adult patients with moderate to severe psoriasis who started treatment with an interleukin (IL)-17 or IL-23 inhibitor between 1 February 2015 and 31 October 2021. Data were collected from 19 distinct hospital and non-hospital-based dermatology centers from Canada, Czech Republic, Italy, Greece, Portugal, Spain, and Switzerland. Kaplan-Meier estimator and proportional hazard Cox regression models were used for drug survival analysis. RESULTS: A total of 4866 treatment courses (4178 patients)-overall time of exposure of 9500 patient-years-were included in this study, with 3164 corresponding to an IL-17 inhibitor (secukinumab, ixekizumab, brodalumab) and 1702 corresponding to an IL-23 inhibitor (guselkumab, risankizumab, tildrakizumab). IL-23 inhibitors had the highest drug survival rates during the entire study period. After 24 months of treatment, the cumulative probabilities of drug survival were 0.92 (95% confidence interval [CI] 0.89-0.95) for risankizumab, 0.90 (95% CI 0.88-0.92) for guselkumab, 0.80 (95% CI 0.76-0.84) for brodalumab, 0.79 (95% CI 0.76-0.82) for ixekizumab, and 0.75 (95% CI 0.73-0.77) for secukinumab. At 36 months, only guselkumab [0.88 (95% CI 0.85-0.91)], ixekizumab [0.73 (95% CI 0.70-0.76)], and secukinumab [0.67 (95% CI 0.65-0.70)] had more than 40 patients at risk of drug discontinuation. Only two drugs had more than 40 patients at risk of drug discontinuation at 48 months, with ixekizumab demonstrating to have a higher cumulative probability of drug survival [0.71 (95% CI 0.68-0.75)] when compared with secukinumab [0.63 (95% CI 0.60-0.66)]. Secondary failure was the main cause for drug discontinuation. According to the final multivariable model, patients receiving risankizumab, guselkumab, and ixekizumab were significantly less likely to discontinue treatment than those receiving secukinumab. Previous exposure to biologic agents, absent family history of psoriasis, higher baseline body mass index (BMI), and higher baseline Psoriasis Area and Severity Index (PASI) were identified as predictors of drug discontinuation. CONCLUSION: The cumulative probability of drug survival of both IL-17 and IL-23 inhibitors was higher than 75% at 24 months, with risankizumab and guselkumab demonstrating to have overall cumulative probabilities ≥ 90%. Biological agent chosen, prior exposure to biologic agents, higher baseline BMI and PASI values, and absence of family history of psoriasis were identified as predictors for drug discontinuation. Risankizumab, guselkumab, and ixekizumab were less likely to be discontinued than secukinumab.

Prevalence of genital and oral human papillomavirus infection among psoriasis patients on biologic therapy.

Current knowledge about human papillomavirus (HPV) infection in psoriasis patients treated with biologics is limited. In this study we evaluated the prevalence of oral and genital HPV infection in psoriasis patients treated with biologics or topical therapy for at least 6 months. The presence of HPV DNA in oral rinse and genital smears was evaluated. In total, 267 patients who met the inclusion criteria and agreed to participate were enrolled: 110 (41.2%) on topical therapy, 84 (31.5%) on anti-TNF-alpha therapy, 31 (11.6%) on anti-IL-12/23 therapy and 42 (15.7%) on anti-IL-17 therapy. The presence of genital HPV infection was detected in 34.6% of men receiving anti-TNF-α treatment, in 25.0% of patients on anti-IL-12/23 and 18.8% of patients on anti-IL-17 therapy. The difference in prevalence was not statistically different from men on topical treatment (26.3%). Prevalence of oral HPV infection was higher across all of the biologic groups (11.9% for anti-TNF-α, 12.9% for anti-IL-12/23 and 19.0% for anti-IL-17) compared to patients on topical therapy (7.3%), but statistically significant only for anti-IL-17 (p < 0.05). The presence of oral HPV infection in patients treated with biologics was significantly higher (44.0%) in patients on long-term biologic treatment (>8 years) compared to patients taking biologics for a shorter period (9.1%; p < 0.01). Our results suggest that patients on biologics for psoriasis have a higher prevalence of oral HPV infection compared to patients on topical treatment. Long-term treatment with biologics seems to be associated with a higher prevalence of oral HPV infection, independent of previous conventional immunosuppressive therapy.

Efficacy, safety, and drug survival of patients with psoriasis treated with IL-17 inhibitors - brodalumab, ixekizumab, and secukinumab: real-world data from the Czech Republic BIOREP registry.

BACKGROUND: Real-world data on the use of interleukin-17 (IL-17) inhibitors for the treatment of psoriasis are limited. OBJECTIVE: To evaluate and compare the efficacy, safety, and drug survival of IL-17 inhibitors. METHODS: This retrospective study analyzed the BIOREP registry data of patients treated with at least one IL-17 inhibitor (secukinumab, ixekizumab, and brodalumab). RESULTS: In total, 949 patients were included. The improvement in PASI score was significant for all drugs, and the proportion of patients achieving PASI 75, 90, and 100 after both 3 and 24 months of therapy was highest for brodalumab, followed by ixekizumab and secukinumab. The Dermatology Life Quality Index score decreased to ˂3 after 3 months and to ˂2 after 24 months of therapy for all inhibitors. Loss of effectiveness was the major reason for discontinuation in 17.2% of patients, followed by adverse events in 3.2% of patients. The drug survival probability was the highest for brodalumab, followed by ixekizumab and secukinumab. Negative predictors for treatment discontinuation were obesity and the number of treatment lines, whereas a positive predictor was the presence of concomitant psoriatic arthritis; sex had no influence. CONCLUSION: This real-life study demonstrated the effectiveness and good safety profile of all currently available IL-17 inhibitors.

A generalised approach for high-throughput instance segmentation of stomata in microscope images.

BACKGROUND: Stomata analysis using microscope imagery provides important insight into plant physiology, health and the surrounding environmental conditions. Plant scientists are now able to conduct automated high-throughput analysis of stomata in microscope data, however, existing detection methods are sensitive to the appearance of stomata in the training images, thereby limiting general applicability. In addition, existing methods only generate bounding-boxes around detected stomata, which require users to implement additional image processing steps to study stomata morphology. In this paper, we develop a fully automated, robust stomata detection algorithm which can also identify individual stomata boundaries regardless of the plant species, sample collection method, imaging technique and magnification level. RESULTS: The proposed solution consists of three stages. First, the input image is pre-processed to remove any colour space biases occurring from different sample collection and imaging techniques. Then, a Mask R-CNN is applied to estimate individual stomata boundaries. The feature pyramid network embedded in the Mask R-CNN is utilised to identify stomata at different scales. Finally, a statistical filter is implemented at the Mask R-CNN output to reduce the number of false positive generated by the network. The algorithm was tested using 16 datasets from 12 sources, containing over 60,000 stomata. For the first time in this domain, the proposed solution was tested against 7 microscope datasets never seen by the algorithm to show the generalisability of the solution. Results indicated that the proposed approach can detect stomata with a precision, recall, and F-score of 95.10%, 83.34%, and 88.61%, respectively. A separate test conducted by comparing estimated stomata boundary values with manually measured data showed that the proposed method has an IoU score of 0.70; a 7% improvement over the bounding-box approach. CONCLUSIONS: The proposed method shows robust performance across multiple microscope image datasets of different quality and scale. This generalised stomata detection algorithm allows plant scientists to conduct stomata analysis whilst eliminating the need to re-label and re-train for each new dataset. The open-source code shared with this project can be directly deployed in Google Colab or any other Tensorflow environment.

Beyond the Dirty Dozen: A Proposed Methodology for Assessing Future Bioweapon Threats.

Background: Defense policy planners and countermeasure developers are often faced with vexing problems involving the prioritization of resources and efforts. This is especially true in the area of Biodefense, where each new emerging infectious disease outbreak brings with it questions regarding the causative agent's potential for weaponization. Recent experience with West Nile Virus, Severe Acute Respiratory Syndrome, Monkeypox, and H1N1 Influenza highlights this problem. Appropriately, in each of these cases, the possibility of bioterrorism was raised, although each outbreak ultimately proved to have a natural origin. In fact, determining whether an outbreak has an unnatural origin can be quite difficult. Thus, the questions remain: could the causative agents of these and other emerging infectious disease outbreaks pose a future weaponization threat? And how great is that threat? Should precious resources be diverted from other defense efforts in order to prepare for possible hostile employment of novel diseases by belligerents? Answering such critical questions requires some form of systematic threat assessment. Methods: Through extensive collaborative work conducted within NATO's Biomedical Advisory Council, we developed a scoring matrix for evaluating the weaponization potential of the causative agents of such diseases and attempted to validate our matrix by examining the reproducibility of data using known threat agents. Our matrix included 12 attributes of a potential weapon and was provided, along with detailed scoring instructions, to 12 groups of biodefense experts in 6 NATO nations. Study participants were asked to score each of these 12 attributes on a scale of 0-3: Infectivity, Infection-to-Disease Ratio (Reliability), Predictability (& Incubation Period), Morbidity & Mortality (Virulence), Ease of Large-Scale Production & Storage, Aerosol Stability, Atmospheric Stability, Ease of Dispersal, Communicability, Prophylactic Countermeasure Availability, Therapeutic Countermeasure Availability, and Ease of Detection. Reproducibility of scoring data was assessed by examining the standard deviations (SD) of mean scores. Results: Our results were unexpected. Several familiar biothreat diseases such as anthrax and tularemia were judged, by our experts, to be less threatening than many others owing to a number of factors including ease of detection, lack of communicability, and the ready availability of countermeasures. Conversely, several toxins were judged by experts to have very high potential as threat agents owing, in part, to their reliability, virulence, and a lack of available countermeasures. Agreement among experts, as determined by lower SD about a mean score, was greater for more familiar threats. Discussion: Our study was designed to provide a concise and east-to-apply set of criteria that could be used by NATO nations to evaluate emerging infectious disease threats with respect to their weaponization potential. Our results were unexpected. We believe that a lack of appropriate weighting factors may explain these results and suggest that future studies weigh each of the 12 proposed criteria based on the intended use of the assessment data and other situational factors. We believe that the greatest value of our study lies in a codification of the attributes of a biological weapon.

Rapid and reliable discrimination between Shigella species and Escherichia coli using MALDI-TOF mass spectrometry.

E. coli-Shigella species are a cryptic group of bacteria in which the Shigella species are distributed within the phylogenetic tree of E. coli. The nomenclature is historically based and the discrimination of these genera developed as a result of the epidemiological need to identify the cause of shigellosis, a severe disease caused by Shigella species. For these reasons, this incorrect classification of shigellae persists to date, and the ability to rapidly characterize E. coli and Shigella species remains highly desirable. Until recently, existing matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) assays used to identify bacteria could not discriminate between E. coli and Shigella species. Here we present a rapid classification method for the E. coli-Shigella phylogroup based on MALDI-TOF MS which is supported by genetic analysis. E. coli and Shigella isolates were collected and genetically characterized by MLVA. A custom reference library for MALDI-TOF MS that represents the genetic diversity of E. coli and Shigella strains was developed. Characterization of E. coli and Shigella species is based on an approach with Biotyper software. Using this reference library it was possible to distinguish between Shigella species and E. coli. Of the 180 isolates tested, 94.4% were correctly classified as E. coli or shigellae. The results of four (2.2%) isolates could not be interpreted and six (3.3%) isolates were classified incorrectly. The custom library extends the existing MALDI-TOF MS method for species determination by enabling rapid and accurate discrimination between Shigella species and E. coli.

Simultaneous Identification of Multiple ß-Lactamases in Acinetobacter baumannii in Relation to Carbapenem and Ceftazidime Resistance, Using Liquid Chromatography-Tandem Mass Spectrometry.

Shotgun proteomics using liquid chromatography-tandem mass spectrometry (LC-MS/MS) was applied to detect ß-lactamases in clinical Acinetobacter baumannii isolates. The correlation of the detection of ß-lactamase proteins (rather than PCR detection of the corresponding genes) with the resistance phenotypes demonstrated an added value for LC-MS/MS in antimicrobial susceptibility testing.

A critical transition in leaf evolution facilitated the Cretaceous angiosperm revolution.

The revolutionary rise of broad-leaved (flowering) angiosperm plant species during the Cretaceous initiated a global ecological transformation towards modern biodiversity. Still, the mechanisms involved in this angiosperm radiation remain enigmatic. Here we show that the period of rapid angiosperm evolution initiated after the leaf interior (post venous) transport path length for water was reduced beyond the leaf interior transport path length for CO2 at a critical leaf vein density of 2.5-5 mm mm(-2). Data and our modelling approaches indicate that surpassing this critical vein density was a pivotal moment in leaf evolution that enabled evolving angiosperms to profit from developing leaves with more and smaller stomata in terms of higher carbon returns from equal water loss. Surpassing the critical vein density may therefore have facilitated evolving angiosperms to develop leaves with higher gas exchange capacities required to adapt to the Cretaceous CO2 decline and outcompete previously dominant coniferous species in the upper canopy.

Reliable identification at the species level of Brucella isolates with MALDI-TOF-MS.

BACKGROUND: The genus Brucella contains highly infectious species that are classified as biological threat agents. The timely detection and identification of the microorganism involved is essential for an effective response not only to biological warfare attacks but also to natural outbreaks. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) is a rapid method for the analysis of biological samples. The advantages of this method, compared to conventional techniques, are rapidity, cost-effectiveness, accuracy and suitability for the high-throughput identification of bacteria. Discrepancies between taxonomy and genetic relatedness on the species and biovar level complicate the development of detection and identification assays. RESULTS: In this study, the accurate identification of Brucella species using MALDI-TOF-MS was achieved by constructing a Brucella reference library based on multilocus variable-number tandem repeat analysis (MLVA) data. By comparing MS-spectra from Brucella species against a custom-made MALDI-TOF-MS reference library, MALDI-TOF-MS could be used as a rapid identification method for Brucella species. In this way, 99.3% of the 152 isolates tested were identified at the species level, and B. suis biovar 1 and 2 were identified at the level of their biovar. This result demonstrates that for Brucella, even minimal genomic differences between these serovars translate to specific proteomic differences. CONCLUSIONS: MALDI-TOF-MS can be developed into a fast and reliable identification method for genetically highly related species when potential taxonomic and genetic inconsistencies are taken into consideration during the generation of the reference library.

Global CO2 rise leads to reduced maximum stomatal conductance in Florida vegetation.

A principle response of C3 plants to increasing concentrations of atmospheric CO(2) (CO(2)) is to reduce transpirational water loss by decreasing stomatal conductance (g(s)) and simultaneously increase assimilation rates. Via this adaptation, vegetation has the ability to alter hydrology and climate. Therefore, it is important to determine the adaptation of vegetation to the expected anthropogenic rise in CO(2). Short-term stomatal opening-closing responses of vegetation to increasing CO(2) are described by free-air carbon enrichments growth experiments, and evolutionary adaptations are known from the geological record. However, to date the effects of decadal to centennial CO(2) perturbations on stomatal conductance are still largely unknown. Here we reconstruct a 34% (±12%) reduction in maximum stomatal conductance (g(smax)) per 100 ppm CO(2) increase as a result of the adaptation in stomatal density (D) and pore size at maximal stomatal opening (a(max)) of nine common species from Florida over the past 150 y. The species-specific g(smax) values are determined by different evolutionary development, whereby the angiosperms sampled generally have numerous small stomata and high g(smax), and the conifers and fern have few large stomata and lower g(smax). Although angiosperms and conifers use different D and a(max) adaptation strategies, our data show a coherent response in g(smax) to CO(2) rise of the past century. Understanding these adaptations of C3 plants to rising CO(2) after decadal to centennial environmental changes is essential for quantification of plant physiological forcing at timescales relevant for global warming, and they are likely to continue until the limits of their phenotypic plasticity are reached.

Climate forcing due to optimization of maximal leaf conductance in subtropical vegetation under rising CO2.

Plant physiological adaptation to the global rise in atmospheric CO(2) concentration (CO(2)) is identified as a crucial climatic forcing. To optimize functioning under rising CO(2), plants reduce the diffusive stomatal conductance of their leaves (g(s)) dynamically by closing stomata and structurally by growing leaves with altered stomatal densities and pore sizes. The structural adaptations reduce maximal stomatal conductance (g(smax)) and constrain the dynamic responses of g(s). Here, we develop and validate models that simulate structural stomatal adaptations based on diffusion of CO(2) and water vapor through stomata, photosynthesis, and optimization of carbon gain under the constraint of a plant physiological cost of water loss. We propose that the ongoing optimization of g(smax) is eventually limited by species-specific limits to phenotypic plasticity. Our model reproduces observed structural stomatal adaptations and predicts that adaptation will continue beyond double CO(2). Owing to their distinct stomatal dimensions, angiosperms reach their phenotypic response limits on average at 740 ppm and conifers on average at 1,250 ppm CO(2). Further, our simulations predict that doubling today's CO(2) will decrease the annual transpiration flux of subtropical vegetation in Florida by ≈60 W·m(-2). We conclude that plant adaptation to rising CO(2) is altering the freshwater cycle and climate and will continue to do so throughout this century.

A novel mucin-sulphatase activity found in Burkholderia cepacia and Pseudomonas aeruginosa.

Lung infections due to Burkholderia cepacia and Pseudomonas aeruginosa in patients with cystic fibrosis (CF) are common, are associated with respiratory morbidity and are a cause of mortality. Respiratory mucin in CF patients is highly sulphated, which increases its resistance to bacterial degradation. Desulphation increases the susceptibility of mucin to degradation by bacterial glycosidases and proteinases, and subsequent deglycosylation may facilitate bacterial colonisation by increasing available substrates and binding sites. This study determined whether clinical and environmental strains of B. cepacia and P. aeruginosa had the ability to desulphate mucin. Mucin-sulphatase activity was tested by incubating bacterial cell suspensions with 35S-sulphated mucins purified from LS174T and HT29-MTX human colon carcinoma cell lines. These mucins were also used to test for differences in substrate specificities. Mucin-sulphatase activity was detected in all nine B. cepacia strains and in four of six P. aeruginosa strains. There was strain variability in the level of mucin-sulphatase activity. Aryl-sulphatase activities of Pseudomonas isolates (determined with methylumbelliferyl sulphate) were c. 20-fold higher than those of B. cepacia strains, and were independent of mucin-sulphatase activity. This is the first report to demonstrate desulphation of mucin by B. cepacia and P. aeruginosa. It is concluded that B. cepacia and P. aeruginosa produce one or more cell-bound glycosulphatase(s), in addition to aryl-sulphatase activity. Mucin-sulphatase activity of B. cepacia and P. aeruginosa may contribute to their association with airway infections in patients with cystic fibrosis.