Neglecting acclimation of photosynthesis under drought can cause significant errors in predicting leaf photosynthesis in wheat.

Extreme climatic events, such as heat waves, cold snaps and drought spells, related to global climate change, have become more frequent and intense in recent years. Acclimation of plant physiological processes to changes in environmental conditions is a key component of plant adaptation to climate change. We assessed the temperature response of leaf photosynthetic parameters in wheat grown under contrasting water regimes and growth temperatures (Tgrowth ). Two independent experiments were conducted under controlled conditions. In Experiment 1, two wheat genotypes were subjected to well-watered or drought-stressed treatments; in Experiment 2, the two water regimes combined with high, medium and low Tgrowth were imposed on one genotype. Parameters of a biochemical C3 -photosynthesis model were estimated at six leaf temperatures for each factor combination. Photosynthesis acclimated more to drought than to Tgrowth . Drought affected photosynthesis by lowering its optimum temperature (Topt ) and the values at Topt of light-saturated net photosynthesis, stomatal conductance, mesophyll conductance, the maximum rate of electron transport (Jmax ) and the maximum rate of carboxylation by Rubisco (Vcmax ). Topt for Vcmax was up to 40°C under well-watered conditions but 24-34°C under drought. The decrease in photosynthesis under drought varied among Tgrowth but was similar between genotypes. The temperature response of photosynthetic quantum yield under drought was partly attributed to photorespiration but more to alternative electron transport. All these changes in biochemical parameters could not be fully explained by the changed leaf nitrogen content. Further model analysis showed that both diffusional and biochemical parameters of photosynthesis and their thermal sensitivity acclimate little to Tgrowth , but acclimate considerably to drought and the combination of drought and Tgrowth . The commonly used modelling approaches, which typically consider the response of diffusional parameters, but ignore acclimation responses of biochemical parameters to drought and Tgrowth , strongly overestimate leaf photosynthesis under variable temperature and drought.

Existing tests vs. novel non-invasive assays for detection of invasive aspergillosis in patients with respiratory diseases.

BACKGROUND: Although existing mycological tests (bronchoalveolar lavage [BAL] galactomannan [GM], serum GM, serum (1,3)-ß-D-glucan [BDG], and fungal culture) are widely used for diagnosing invasive pulmonary aspergillosis (IPA) in non-hematological patients with respiratory diseases, their clinical utility in this large population is actually unclear. We aimed to resolve this clinical uncertainty by evaluating the diagnostic accuracy and utility of existing tests and explore the efficacy of novel sputum-based Aspergillus assays. METHODS: Existing tests were assessed in a prospective and consecutive cohort of patients with respiratory diseases in West China Hospital between 2016 and 2019 while novel sputum assays (especially sputum GM and Aspergillus-specific lateral-flow device [LFD]) in a case-controlled subcohort. IPA was defined according to the modified European Organization for Research and Treatment of Cancer/Mycoses Study Group criteria. Sensitivity and specificity were computed for each test and receiver operating characteristic (ROC) curve analysis was performed. RESULTS: The entire cohort included 3530 admissions (proven/probable IPA = 66, no IPA = 3464) and the subcohort included 127 admissions (proven/probable IPA = 38, no IPA = 89). Sensitivity of BAL GM (≥1.0 optical density index [ODI]: 86% [24/28]) was substantially higher than that of serum GM (≥0.5 ODI: 38% [39/102]) ( χ2  = 19.83, P   <  0.001), serum BDG (≥70 pg/mL: 33% [31/95]) ( χ2  = 24.65, P  < 0.001), and fungal culture (33% [84/253]) ( χ2  = 29.38, P  < 0.001). Specificity varied between BAL GM (≥1.0 ODI: 94% [377/402]), serum GM (≥0.5 ODI: 95% [2130/2248]), BDG (89% [1878/2106]), and culture (98% [4936/5055]). Sputum GM (≥2.0 ODI) had similar sensitivity (84% [32/38]) (Fisher's exact P  = 1.000) to and slightly lower specificity (87% [77/89]) ( χ2  = 5.52, P  = 0.019) than BAL GM (≥1.0 ODI). Area under the ROC curve values were comparable between sputum GM (0.883 [0.812-0.953]) and BAL GM (0.901 [0.824-0.977]) ( P  = 0.734). Sputum LFD had similar specificity (91% [81/89]) ( χ2  = 0.89, P  = 0.345) to and lower sensitivity (63% [24/38]) ( χ2  = 4.14, P  = 0.042) than BAL GM (≥1.0 ODI), but significantly higher sensitivity than serum GM (≥0.5 ODI) ( χ2  = 6.95, P  = 0.008), BDG ( χ2  = 10.43, P  = 0.001), and fungal culture ( χ2  = 12.70, P  < 0.001). CONCLUSIONS: Serum GM, serum BDG, and fungal culture lack sufficient sensitivity for diagnosing IPA in respiratory patients. Sputum GM and LFD assays hold promise as rapid, sensitive, and non-invasive alternatives to the BAL GM test.

A case report of acute fibrinous and organizing pneumonia.

RATIONALE: Acute fibrinous and organizing pneumonia (AFOP) is a newly evolving rare non-infectious lung pathology, characterized by intra-alveolar fibrin balls on histology. It is usually difficult to be diagnosed and mistaken for other lung diseases. PATIENT CONCERNS: In this article, an interesting case about a male patient with a 15-day history of high-grade fever, chills, and no productive cough was presented. He was misdiagnosed as the lung infection early, but exhibited no response to the antibiotic therapy. DIAGNOSIS: The diagnosis of AFOP was determined by the lung biopsy and pathology. INTERVENTIONS: With the diagnosis of AFOP, all antibiotics were discontinued, and 40 mg methylprednisolone daily was given intravenously. OUTCOMES: The patient responded well to the treatment with steroids. LESSONS: AFOP is a rare lung disease characterized by bilateral basilar infiltrates and histological findings of organizing pneumonia and intra-alveolar fibrin in the form of "fibrin balls". Lung biopsy and histopathology were the most important diagnostic methods for the AFOP. Glucocorticoid was an effective drug for the treatment. Subacute patients of AFOP have excellent prognosis with corticosteroids.

Sputum signatures for invasive pulmonary aspergillosis in patients with underlying respiratory diseases (SPARED): study protocol for a prospective diagnostic trial.

BACKGROUND: Invasive pulmonary aspergillosis (IPA) has been increasingly reported in patients with underlying respiratory diseases (URD). Early diagnosis of IPA is crucial for mortality reduction and improved prognosis, yet remains difficult. Existing diagnostic tools for IPA largely rely on the detection of biomarkers based on serum or bronchoalveolar lavage fluid (BALF), both of which have their limitations. The use of sputum sample is non-invasive, and Aspergillus detection is feasible; however, the usefulness of sputum biomarkers for the diagnosis of IPA, especially in patients with URD, has not been systematically studied. METHODS: This is a prospective diagnostic trial. At least 118 participants will be recruited from respiratory wards and intensive care units. IPA is defined according to the EORTC/MSG criteria modified for patients with URD. Induced sputum and blood will be collected, and BALF will be obtained by bronchoscopy. Sputum biomarkers, including galactomannan, Aspergillus DNA, triacetylfusarinine and bis(methylthio)gliotoxin will be determined, and the presence of a JF5 antigen will be examined with a lateral fluid device. The sensitivity, specificity, negative predictive value, positive predictive value and diagnostic odds ratio will be computed for different biomarkers and compared using the McNemar χ2 test. Receiver operating characteristic analyses will be performed, and the cut-off values will be established. Participants will receive follow-up evaluations at 3 months and 6 months after recruitment. The difference in hospital stay and survival will be analysed, and the relationships between the levels of biomarkers and hospital stay and survival will be analysed via regression models. DISCUSSION: We have developed and verified the feasibility of Aspergillus-related biomarker assays for sputum. The study findings will contribute to a novel look at the diagnostic performance of sputum biomarkers in IPA and provide important insight into the improvement of the early diagnosis of IPA, particularly in patients with URD. TRIAL REGISTRATION: This study has been registered with the Chinese Clinical Trial Registry ( ChiCTR-DPD-16009070 ) on 24th of August 2016.

Diabetes mellitus and the risk of multidrug resistant tuberculosis: a meta-analysis.

The high prevalence of diabetes mellitus (DM) among multidrug resistant tuberculosis (MDR-TB) patients is a serious cause for concern. We conducted a meta-analysis to determine whether DM is an independent risk factor for MDR-TB. Electronic literature searches of the PubMed, Web of Science and EMBASE databases up to July 12, 2016 were conducted. The pooled adjusted odds ratio (OR) and 95% confidence intervals (CIs) were calculated using the random effects model with STATA 12.0 software. In total 13 studies, including 9289 individuals with TB, were included in this meta-analysis. Significant association between DM and MDR-TB (OR = 1.71; 95% CI = 1.32, 2.22) was identified. Subgroup analyses showed that: 1) Pooled OR was 1.25 (95% CI: 0.82-1.91) for cross-sectional studies, and was 2.14 (95% CI: 1.51-3.02) for longitudinal studies; 2) The pooled OR was 1.69 (95% CI:1.09-2.62) for primary MDR-TB, 1.94 (95% CI:1.42-2.65) for any MDR-TB, and 0.85 for secondary MDR-TB (95% CI: 0.29-2.54); 3) DM was significantly associated with MDR-TB in both Caucasian (OR = 2.26, 95% CI: 1.66-3.07) and Asian (OR = 1.40, 95% CI: 1.01-1.95) subgroups. No evidence of publication bias was identified. In conclusion, the pooling analysis indicated that DM was an independent risk factor for MDR-TB, especially for primary MDR-TB.

Performance of interferon-γ release assay in the diagnosis of tuberculous lymphadenitis: a meta-analysis.

BACKGROUND: The diagnostic values of interferon-gamma release assays (IGRA) in tuberculosis (TB) vary a lot with different site of infections, with especially higher sensitivities in chronic forms of TB such as tuberculosis of the lymph node. We conducted a meta-analysis to comprehensively evaluate the overall accuracy of diagnostic IGRA for tuberculous lymphadenitis. METHODS: Pubmed, Web of Science, EMBASE, Wanfang and CNKI databases up to February 17, 2017 were searched to identify published studies. The study quality was evaluated using the QUADAS-2 checklist. The pooled estimates of diagnostic parameters were generated using a bivariate random-effects model and summary receiver operating characteristic (SROC) curves were used to summarize global performance. RESULTS: A total of ten qualified studies, performed in Korea or China, including 1,084 patients, were enrolled in this meta-analysis. The pooled estimates of diagnostic accuracy were as follows: sensitivity, 0.89 (95% CI [0.85-0.92]); specificity, 0.81 (95% CI [0.77-0.83]); positive likelihood ratio (PLR), 4.25 (95% CI [2.79-6.47]); negative likelihood ratio (NLR), 0.16 (95% CI [0.12-0.22]); and area under the curve (AUC) was 0.93. According to subgroup analyses, studies conducted using QuantiFERON-TB, in Korean population and focusing on cervical lymphadenitis exhibited relative higher specificity while lower sensitivity. No evidence of publication bias was identified. CONCLUSIONS: IGRA exhibits high diagnostic accuracy in tuberculous lymphadenitis. The diagnostic value of IGRA differed by different IGRA methods, ethnicity and lymphadenitis location. Our conclusion may be more applicable to population from TB prevalent areas.

Risk and Prognostic Factors for Multidrug-Resistant Acinetobacter Baumannii Complex Bacteremia: A Retrospective Study in a Tertiary Hospital of West China.

BACKGROUND: The increasing prevalence and mortality of multidrug-resistant (MDR) Acinetobacter baumannii complex-associated infections, especially bacteremia, in health care settings poses a great threat to public health. We proceeded to investigate the risk and prognostic factors for MDR A. baumannii complex bacteremia in mainland China. METHODS: This retrospective study was conducted at West China Hospital from January 2009 to December 2013. Using a computer-assisted microbiology laboratory database, patients with MDR A. baumannii complex bacteremia were included as the case group, while those infected with non-MDR A. baumannii complex were selected as the control group. The clinical data were collected and analyzed. RESULTS: There were 241 non-duplicated A. baumannii complex blood isolates identified in our research, with the overall rate of multidrug resistance reaching 75.52% over the past five years. Using multivariate logistic analysis, being in the intensive care unit (ICU) (adjusted odds ratio [aOR], 5.84; 95% confidence interval [CI], 1.67-20.44), increased Pittsburgh bacteremia score (aOR, 6.55; 95% CI, 1.27-33.70) and use of carbapenem (aOR, 8.90; 95% CI, 1.71-46.30) were independent risk factors for MDR acquisition among patients with A. baumannii complex bacteremia. Older age (aOR, 1.02; 95% CI, 1.00-1.04), being post-transplantation (aOR, 5.21; 95% CI, 1.13-24.04), having a higher Pittsburgh bacteremia score (aOR, 2.19; 95% CI, 1.08-4.47) and having a lower level of albumin (aOR, 0.93; 95% CI, 0.88-0.99) were identified as independent risk factors for 30-day mortality in patients with MDR A. baumannii complex bacteremia. CONCLUSION: In conclusion, our research revealed the risk factors associated with acquisition of and mortality from MDR A. baumannii complex bacteremia, which may be used to prioritize infection control practices and prognostic evaluations.

Influence of carbapenem resistance on mortality of patients with Pseudomonas aeruginosa infection: a meta-analysis.

Treatment of infectious diseases caused by the carbapenem-resistant Pseudomonas aeruginosa (CRPA) is becoming more challenging with each passing year. We conducted a meta-analysis to assess the impact of carbapenem resistance on mortality of patients with P. aeruginosa infection. We searched PUBMED, Web of science, EMBASE, Google Scholar and the Cochrane Library up to December 25, 2014, to identify published cohort or case-control studies. 17 studies, including 6660 patients carrying P. aeruginosa, were identified. The pooling analysis indicated that patients infected with CRPA had significantly higher mortality than those infected with carbapenem-susceptible P. aeruginosa (CSPA) (crude OR = 1.64; 95%CI = 1.40, 1.93; adjusted OR = 2.38; 95%CI = 1.53, 3.69). The elevated risk of mortality in patients with CRPA infection was not lessened when stratified by study design, sites of infection, or type of carbapenem, except that the estimate effect vanished in CRPA high-incidence region, South America (crude OR = 1.12; 95%CI = 0.64, 1.99). Begg's (z = 0.95, p = 0.34) and Egger's test (t = 1.23, p = 0.24) showed no evidence of publication bias. Our results suggest that carbapenem resistance may increase the mortality of patients with P. aeruginosa infection, whether under univariate or multivariate analysis.