CAM photosynthesis in Bulnesia retama (Zygophyllaceae), a non-succulent desert shrub from South America.

BACKGROUND AND AIMS: Bulnesia retama is a drought-deciduous, xerophytic shrub from arid landscapes of South America. In a survey of carbon isotope ratios (δ13C) in specimens from the field, B. retama exhibited less negative values, indicative of CAM or C4 photosynthesis. Here, we investigate whether B. retama is a C4 or CAM plant. METHODS: Gas-exchange responses to intercellular CO2, diurnal gas-exchange profiles, δ13C and dawn vs. afternoon titratable acidity were measured on leaves and stems of watered and droughted B. retama plants. Leaf and stem cross-sections were imaged to determine whether the tissues exhibited succulent CAM or C4 Kranz anatomy. KEY RESULTS: Field-collected stems and fruits of B. retama exhibited δ13C between -16 and -19 ‰. Plants grown in a glasshouse from field-collected seeds had leaf δ13C values near -31 ‰ and stem δ13C values near -28 ‰. The CO2 response of photosynthesis showed that leaves and stems used C3 photosynthesis during the day, while curvature in the nocturnal response of net CO2 assimilation rate (A) in all stems, coupled with slightly positive rates of A at night, indicated modest CAM function. C4 photosynthesis was absent. Succulence was absent in all tissues, although stems exhibited tight packing of the cortical chlorenchyma in a CAM-like manner. Tissue titratable acidity increased at night in droughted stems. CONCLUSIONS: Bulnesia retama is a weak to modest C3 + CAM plant. This is the first report of CAM in the Zygophyllaceae and the first showing that non-succulent, xerophytic shrubs use CAM. CAM alone in B. retama was too limited to explain less negative δ13C in field-collected plants, but combined with effects of low stomatal and mesophyll conductance it could raise δ13C to observed values between -16 and -19 ‰. Modest CAM activity, particularly during severe drought, could enable B. retama to persist in arid habitats of South America.

Emerging EGFR-Mutated Subclones in a Patient With Metastatic ALK-Rearranged Lung Adenocarcinoma Treated With ALK-Targeted Therapy: A Case Report.

We report a case of pathologically confirmed ALK-rearranged metastatic lung adenocarcinoma with emergence of EGFR L858R mutation on disease progression after two lines of treatment with ALK inhibitors. At initial diagnosis, tumoral ALK expression was detected without EGFR mutation by standard allele-specific polymerase chain reaction. There was sustained partial response to both first-line crizotinib and subsequent brigatinib. On disease progression to brigatinib, result of a liquid biopsy with circulating tumor DNA revealed only EGFR L858R, which was confirmed by tumor rebiopsy on the supraclavicular lymph node. The patient was then treated initially with pemetrexed and carboplatin, and erlotinib was subsequently added after two cycles of chemotherapy. The combination treatment has resulted in very good partial response and mild adverse effects. The overall clinical course would suggest the initial presence of two separate tumor clones, with ALK dominance at diagnosis. The subsequent breakthrough disease progression after initial response to brigatinib was related to uncontrolled growth of the EGFR-mutated tumor subpopulation. The implication on defining molecular mechanism of acquired resistance and treatment strategy would be discussed.

Digest: Between invasive species and a hot place: Plant evolution under climate change.

Will climate change lead to invasive species evolving faster than native or naturalized species? Gianoli and Molina-Montenegro showed that, under warming and drought, the evolution of photosynthetic capacity does not always favor invasive species. These data raise interesting questions for the study of evolution of invasive species under climate change.

Topical imiquimod before intradermal trivalent influenza vaccine for protection against heterologous non-vaccine and antigenically drifted viruses: a single-centre, double-blind, randomised, controlled phase 2b/3 trial.

BACKGROUND: Pretreatment with topical imiquimod, a synthetic agonist of toll-like receptor 7, significantly improved the immunogenicity of influenza vaccination in elderly people. We aimed to clarify its effect in a younger age group. METHODS: In this double-blind, randomised controlled trial, we enrolled healthy volunteers aged 18-30 years in early 2014 to receive the 2013-14 northern-hemisphere winter trivalent influenza vaccine at the Queen Mary Hospital, (Hong Kong, China). Eligible participants were randomly assigned (1:1:1:1) to one of the four vaccination groups: the study group, topical imiquimod-cream followed by intradermal trivalent influenza vaccine (INF-Q-ID), or one of three control groups, topical aqueous-cream control followed by intradermal trivalent influenza vaccine (INF-C-ID), topical aqueous-cream control followed by intramuscular trivalent influenza vaccine (INF-C-IM), and topical imiquimod-cream followed by intradermal normal-saline injection (SAL-Q-ID). Randomisation was by computer-generated lists in blocks of four. The type of topical treatment was masked from volunteers and investigators, although not from the study nurse. Serum haemagglutination-inhibition and microneutralisation-antibody titres were assayed. The primary outcome was seroconversion at day 7 after treatment for three vaccine strains of influenza (A/California/07/2009 H1N1-like virus [A/California/H1N1], A/Victoria/361/2011 H3N2-like virus [A/Victoria/H3N2], and B/Massachusetts/2/2012-like virus [B/Yamagata lineage]) and four non-vaccine strains (A/HK/485197/14 [H3N2 Switzerland-like lineage], prototype A/WSN/1933 [H1N1], A/HK/408027/09 [prepandemic seasonal H1N1], and B/HK/418078/11 [Victoria lineage]). Analysis was done on an intention-to-treat basis. This trial is registered with ClinicalTrials.gov, number NCT02103023. FINDINGS: We enrolled 160 healthy volunteers between March 1 and May 31, 2014, and 40 participants were randomly assigned to each study group. For the A/California/H1N1 strain, seroconversion at day 7 occurred in 39 participants (98%) in the INF-Q-ID group, 25 (63%) in the INF-C-ID group, 18 (45%) in the INF-C-IM group, and none in the SAL-Q-ID group; for the A/Victoria/H3N2, this was 30 (75%) in the INF-Q-ID group, four (10%) in the INF-C-ID group, four (10%) in the INF-C-IM group, and none in the SAL-Q-ID group; and for the B/Massachusetts (Yamagata lineage) strain, this was 36 (90%) in the INF-Q-ID group, 27 (68%) in the INF-C-ID group, 17 (43%) in the INF-C-IM group, and one (3%) in the SAL-Q-ID group (p<0·0001 for all three vaccine strains). Adverse reactions were infrequent and self-limited and did not differ between the four groups. Furthermore, the seroconversion rate against the four non-vaccine strains was better in the INF-Q-ID group than in the control groups on days 7 and 21 (p<0·0001). The most common adverse events were grade 1 redness (five participants in the INF-Q-ID group, three in INF-C-ID, one in INF-C-IM, and one in SAL-Q-ID) and grade 1 swelling (seven participants in INF-Q-ID group, five in INF-C-ID, three in INF-C-IM, and two in SAL-Q-ID. INTERPRETATION: Topical application of imiquimod before intradermal trivalent influenza vaccine significantly improved immunogenicity against the vaccine influenza strains in young healthy individuals and increased immunogenicity against the non-vaccine strains, especially the antigenically drifted H3N2 strain of 2015, which was not included in the 2013-14 recommended vaccine. Further studies should be done to establish the efficacy and safety of this approach for other injectable vaccines to augment the onset and range of protection. FUNDING: The Shaw Foundation Hong Kong, Health and Medical Research Fund (Hong Kong, China), The Consultancy Service for Enhancing Laboratory Surveillance of Emerging Infectious Disease for the HKSAR (Department of Health, Hong Kong, China), The Providence Foundation, Respiratory Viral Research Foundation.

Inflammation targeted Gd(3+)-based MRI contrast agents imaging tumor and rheumatoid arthritis models.

Inflammatory responses are closely related to cancer progression and several diseases. Anti-inflammatory drugs that bind to inducible enzymes can be used as biomarkers for molecular imaging. Selective targeted contrast agents are expected to improve contrast-to-noise ratio (CNR) in MRI at the site of inflammation. In this work, three new Gd(3+) DO3A-amide MRI contrast agents (CAs) that conjugated to mefenamic acid (MA), a commonly used nonsteroidal anti-inflammatory drug (NSAID), through different linkers, ethylenediamine (GdL1), 2,2'-oxidiethylamine (GdL2) and 4,7,10-trioxa-1,13-tridecanediamine (GdL3) were studied. Their relaxivities were GdL1 (4.74 mM(-1) s(-1)), GdL2 (4.77 mM(-1) s(-1)), and GdL3 (4.95 mM(-1) s(-1)) at 400 MHz at 25 °C. Their serum albumin binding properties were studied by tryptophan emission-quenching experiments, with GdL1 showing a preferential binding toward HSA and BSA as compared with GdL2 and GdL3. They showed low cytotoxicities toward HeLa cells at high concentration (0.5 mM) and high cellular uptake in U87 cells as compared with GdDOTA. In vivo MRI showed increased T1-weighted contrast after intravenous injection of the agents. Moreover, T1 contrast was significantly enhanced for 1.5 h in the U87 tumor model and 2 h in the arthritis joint in adjuvant-induced arthritis (AIA) model at dosages of 0.1 and 0.03 mmol/kg, respectively. Most of the agents were cleared at 24 h post-administration in the AIA model with no observable T1 contrast. GdL1-3 showed superior retentions and intensity enhancements (IEs) at the kidney, liver, tumor, and arthritis joint to those of GdDOTA. GdL3 showed the highest relaxivity and IE at the arthritis joint and is therefore a potential candidate to be developed as MRI CAs that target inflammation.