Aggregation-induced emission of 1-methyl-1,2,3,4,5-pentaphenylsilole

Aggregation greatly boosts emission efficiency of the silole, turning it from a weak luminophor into a strong emitter.

Negative control of p53 by Sir2alpha promotes cell survival under stress

The NAD-dependent histone deacetylation of Sir2 connects cellular metabolism with gene silencing as well as aging in yeast. Here, we show that mammalian Sir2alpha physically interacts with p53 and attenuates p53-mediated functions. Nicotinamide (Vitamin B3) inhibits an NAD-dependent p53 deacetylation induced by Sir2alpha, and also enhances the p53 acetylation levels in vivo. Furthermore, Sir2alpha represses p53-dependent apoptosis in response to DNA damage and oxidative stress, whereas expression of a Sir2alpha point mutant increases the sensitivity of cells in the stress response. Thus, our findings implicate a p53 regulatory pathway mediated by mammalian Sir2alpha. These results have significant implications regarding an important role for Sir2alpha in modulating the sensitivity of cells in p53-dependent apoptotic response and the possible effect in cancer therapy.

Observation of Gravitational Waves from a Binary Black Hole Merger

On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-Wave Observatory simultaneously observed a transient gravitational-wave signal. The signal sweeps upwards in frequency from 35 to 250 Hz with a peak gravitational-wave strain of 1.0×10(-21). It matches the waveform predicted by general relativity for the inspiral and merger of a pair of black holes and the ringdown of the resulting single black hole. The signal was observed with a matched-filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203,000 years, equivalent to a significance greater than 5.1σ. The source lies at a luminosity distance of 410(-180)(+160)  Mpc corresponding to a redshift z=0.09(-0.04)(+0.03). In the source frame, the initial black hole masses are 36(-4)(+5)M⊙ and 29(-4)(+4)M⊙, and the final black hole mass is 62(-4)(+4)M⊙, with 3.0(-0.5)(+0.5)M⊙c(2) radiated in gravitational waves. All uncertainties define 90% credible intervals. These observations demonstrate the existence of binary stellar-mass black hole systems. This is the first direct detection of gravitational waves and the first observation of a binary black hole merger.

Requirement for glycogen synthase kinase-3beta in cell survival and NF-kappaB activation

Glycogen synthase kinase-3 (GSK-3)-alpha and -beta are closely related protein-serine kinases, which act as inhibitory components of Wnt signalling during embryonic development and cell proliferation in adult tissues. Insight into the physiological function of GSK-3 has emerged from genetic analysis in Drosophila, Dictyostelium and yeast. Here we show that disruption of the murine GSK-3beta gene results in embryonic lethality caused by severe liver degeneration during mid-gestation, a phenotype consistent with excessive tumour necrosis factor (TNF) toxicity, as observed in mice lacking genes involved in the activation of the transcription factor activation NF-kappaB. GSK-3beta-deficient embryos were rescued by inhibition of TNF using an anti-TNF-alpha antibody. Fibroblasts from GSK-3beta-deficient embryos were hypersensitive to TNF-alpha and showed reduced NF-kappaB function. Lithium treatment (which inhibits GSK-3; refs 8, 9) sensitized wild-type fibroblasts to TNF and inhibited transactivation of NF-kappaB. The early steps leading to NF-kappaB activation (degradation of I-kappaB and translocation of NF-kappaB to the nucleus) were unaffected by the loss of GSK-3beta, indicating that NF-kappaB is regulated by GSK-3beta at the level of the transcriptional complex. Thus, GSK-3beta facilitates NF-kappaB function.

Deacetylation of p53 modulates its effect on cell growth and apoptosis

The p53 tumour suppressor is a transcriptional factor whose activity is modulated by protein stability and post-translational modifications including acetylation. The mechanism by which acetylated p53 is maintained in vivo remains unclear. Here we show that the deacetylation of p53 is mediated by an histone deacetylase-1 (HDAC1)-containing complex. We have also purified a p53 target protein in the deacetylase complexes (designated PID; but identical to metastasis-associated protein 2 (MTA2)), which has been identified as a component of the NuRD complex. PID specifically interacts with p53 both in vitro and in vivo, and its expression reduces significantly the steady-state levels of acetylated p53. PID expression strongly represses p53-dependent transcriptional activation, and, notably, it modulates p53-mediated cell growth arrest and apoptosis. These results show that deacetylation and functional interactions by the PID/MTA2-associated NuRD complex may represent an important pathway to regulate p53 function.

Administration of Lactobacillus helveticus NS8 improves behavioral, cognitive, and biochemical aberrations caused by chronic restraint stress

Increasing numbers of studies have suggested that the gut microbiota is involved in the pathophysiology of stress-related disorders. Chronic stress can cause behavioral, cognitive, biochemical, and gut microbiota aberrations. Gut bacteria can communicate with the host through the microbiota-gut-brain axis (which mainly includes the immune, neuroendocrine, and neural pathways) to influence brain and behavior. It is hypothesized that administration of probiotics can improve chronic-stress-induced depression. In order to examine this hypothesis, the chronic restraint stress depression model was established in this study. Adult specific pathogen free (SPF) Sprague-Dawley rats were subjected to 21 days of restraint stress followed by behavioral testing (including the sucrose preference test (SPT), elevated-plus maze test, open-field test (OFT), object recognition test (ORT), and object placement test (OPT)) and biochemical analysis. Supplemental Lactobacillus helveticus NS8 was provided every day during stress until the end of experiment, and selective serotonin reuptake inhibitor (SSRI) citalopram (CIT) served as a positive control. Results showed that L. helveticus NS8 improved chronic restraint stress-induced behavioral (anxiety and depression) and cognitive dysfunction, showing an effect similar to and better than that of CIT. L. helveticus NS8 also resulted in lower plasma corticosterone (CORT) and adrenocorticotropic hormone (ACTH) levels, higher plasma interleukin-10 (IL-10) levels, restored hippocampal serotonin (5-HT) and norepinephrine (NE) levels, and more hippocampal brain-derived neurotrophic factor (BDNF) mRNA expression than in chronic stress rats. Taken together, these results indicate an anti-depressant effect of L. helveticus NS8 in rats subjected to chronic restraint stress depression and that this effect could be due to the microbiota-gut-brain axis. They also suggest the therapeutic potential of L. helveticus NS8 in stress-related and possibly other kinds of depression.

Characterization of the distinct orthotopic bone-forming activity of 14 BMPs using recombinant adenovirus-mediated gene delivery

Efficacious bone regeneration could revolutionize the clinical management of bone and musculoskeletal disorders. Although several bone morphogenetic proteins (BMPs) (mostly BMP-2 and BMP-7) have been shown to induce bone formation, it is unclear whether the currently used BMPs represent the most osteogenic ones. Until recently, comprehensive analysis of osteogenic activity of all BMPs has been hampered by the fact that recombinant proteins are either not biologically active or not available for all BMPs. In this study, we used recombinant adenoviruses expressing the 14 types of BMPs (AdBMPs), and demonstrated that, in addition to currently used BMP-2 and BMP-7, BMP-6 and BMP-9 effectively induced orthotopic ossification when either AdBMP-transduced osteoblast progenitors or the viral vectors were injected into the quadriceps of athymic mice. Radiographic and histological evaluation demonstrated that BMP-6 and BMP-9 induced the most robust and mature ossification at multiple time points. BMP-3, a negative regulator of bone formation, was shown to effectively inhibit orthotopic ossification induced by BMP-2, BMP-6, and BMP-7. However, BMP-3 exerted no inhibitory effect on BMP-9-induced bone formation, suggesting that BMP-9 may transduce osteogenic signaling differently. Our findings suggest that BMP-6 and BMP-9 may represent more effective osteogenic factors for bone regeneration.

The PI3K/AKT/mTOR signaling pathway in osteoarthritis: a narrative review

Osteoarthritis (OA) is a complicated degenerative disease that affects whole joint tissue. Currently, apart from surgical approaches to treat late stage OA, effective treatments to reverse OA are not available. Thus, the mechanisms leading to OA, and more effective approaches to treat OA should be investigated. According to available evidence, the PI3K/AKT/mTOR signaling pathway is essential for normal metabolism of joint tissues, but is also involved in development of OA. To provide a wide viewpoint to roles of PI3K/AKT/mTOR signaling pathway in osteoarthritis, a comprehensive literature search was performed using PubMed terms 'PI3K OR AKT OR mTOR' and 'osteoarthritis'. This review highlights the role of PI3K/AKT/mTOR signaling in cartilage degradation, subchondral bone dysfunction, and synovial inflammation, and discusses how this signaling pathway affects development of the disease. We also summarize recent evidences of therapeutic approaches to treat OA by targeting the PI3K/AKT/mTOR pathway, and discuss potential challenges in developing these strategies for clinical treatment of OA.

The function of PML in p53-dependent apoptosis

The PML gene of acute promyelocytic leukaemia (APL) encodes a growth- and tumour-suppresor protein that is essential for several apoptotic signals. The mechanisms by which PML exerts its pro-apoptotic function are still unknown. Here we show that PML acts as a transcriptional co-activator with p53. PML physically interacts with p53 both in vitro and in vivo and co-localizes with p53 in the PML nuclear body (PML-NB). The co-activatory role of PML depends on its ability to localize in the PML-NB. p53-dependent, DNA-damage-induced apoptosis, transcriptional activation by p53, the DNA-binding ability of p53, and the induction of p53 target genes such as Bax and p21 upon gamma-irradiation are all impaired in PML-/- primary cells. These results define a new PML-dependent, p53-regulatory pathway for apoptosis and shed new light on the function of PML in tumour suppression.

Specific inhibition of cyclooxygenase 2 restores antitumor reactivity by altering the balance of IL-10 and IL-12 synthesis

Cyclooxygenase-2 (COX-2), the enzyme at the rate-limiting step of prostanoid production, has been found to be overexpressed in human lung cancer. To evaluate lung tumor COX-2 modulation of antitumor immunity, we studied the antitumor effect of specific genetic or pharmacological inhibition of COX-2 in a murine Lewis lung carcinoma (3LL) model. Inhibition of COX-2 led to marked lymphocytic infiltration of the tumor and reduced tumor growth. Treatment of mice with anti-PGE2 mAb replicated the growth reduction seen in tumor-bearing mice treated with COX-2 inhibitors. COX-2 inhibition was accompanied by a significant decrement in IL-10 and a concomitant restoration of IL-12 production by APCs. Because the COX-2 metabolite PGE2 is a potent inducer of IL-10, it was hypothesized that COX-2 inhibition led to antitumor responses by down-regulating production of this potent immunosuppressive cytokine. In support of this concept, transfer of IL-10 transgenic T lymphocytes that overexpress IL-10 under control of the IL-2 promoter reversed the COX-2 inhibitor-induced antitumor response. We conclude that abrogation of COX-2 expression promotes antitumor reactivity by restoring the balance of IL-10 and IL-12 in vivo.

The majority of N-methyl-D-aspartate receptor complexes in adult rat cerebral cortex contain at least three different subunits (NR1/NR2A/NR2B)

A monoclonal antibody (R1JHL) against the NR1 subunit of the N-methyl-D-aspartate (NMDA) receptor has been developed that recognizes an epitope in the region of the amino-terminal amino acids 341-561 (a region common to all splice variants of NR1). This monoclonal antibody identifies a broad band at 115 kDa in immunoblots using membranes from NR1-transfected cells and from rat brain tissue. No cross-reactivity with any NR2 subunit is seen. With the goal to determine quantitatively the subunit composition of cortical NMDA receptors, we used the monoclonal antibody to NR1 and polyclonal antibodies against the NR2A and NR2B subunits to perform immunoprecipitations of receptor subunits from solubilized adult rat cortical membranes. Solubilization of the receptor subunits was accomplished under both nondenaturing (native) conditions, under which the subunits seem to remain associated with one another, and denaturing conditions, under which the subunits are associated from each other. Although each of these antibodies selectively immunoprecipitates only its corresponding (cognate) subunit when the subunits have been solubilized under denaturing conditions, each of the antibodies immunoprecipitates a sizable fraction of the other two NMDA receptor subunits when membranes are solubilized under nondenaturing conditions, indicating an interaction in situ. Using quantitative immunoblot analysis of the three subunits in both the pellets and supernatants from the immunoprecipitations, we found 1) the dominant NMDA receptor complex in adult rat cortex contains at least three subunits, NR1/NR2A/NR2B; 2) a smaller fraction of NMDA receptors are composed of only two subunits, NR1/NR2B or NR1/NR2A; 3) there are no complexes that contain NR2A/NR2B that do not contain NR1; 4) only a small fraction of each subunit is not associated with any other NMDA receptor subunit; 5) no coimmunoprecipitation of noncognate subunits occurs unless the subunits are assembled with each other in situ; and 6) there is no physical interaction between these NMDA receptor subunits and the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor GluR2 or GluR3 subunits. These results suggest that functional studies with recombinant receptors composed of at least three subunits may be the most physiologically meaningful.

Placental abnormalities in mouse embryos lacking the orphan nuclear receptor ERR-beta

Classical endocrine studies have shown that steroid hormones are required for the maintenance of pregnancy and placental viability. The oestrogen-receptor-related receptor beta (ERR-beta) is an orphan member of the superfamily of nuclear hormone receptors. Although ERR-beta is homologous to the oestrogen receptor and binds the oestrogen response element, it is not activated by oestrogens. Expression of ERR-beta during embryogenesis defines a subset of extra-embryonic ectoderm that subsequently forms the dome of the chorion, suggesting that ERR-beta may be involved in early placental development. Homozygous mutant embryos generated by targeted disruption of the Estrrb gene have severely impaired placental formation, and die at 10.5 days post-coitum. The mutants display abnormal chorion development associated with an overabundance of trophoblast giant cells and a severe deficiency of diploid trophoblast. The phenotype can be rescued by aggregation of Estrrb mutant embryos with tetraploid wild-type cells, which contribute exclusively to extra-embryonic tissues. Our results indicate that ERR-beta has an important role in early placentation, and suggest that an inductive signal originating from or modified by the chorion is required for normal trophoblast proliferation and differentiation.

C2 region-derived peptides inhibit translocation and function of beta protein kinase C in vivo

RACK1 is a protein kinase C (PKC)-binding protein that fulfills the criteria previously established for a receptor for activated C-kinase (RACK). If binding of PKC to RACK anchors the activated enzyme near its protein substrates, then inhibition of this binding should inhibit translocation and function of the enzyme in vivo. Here, we have identified such inhibitors that mimic the RACK1-binding site on beta PKC. We first found that a C2-containing fragment, but not a C1-containing fragment of beta PKC, bound to RACK1 and inhibited subsequent beta PKC binding. The RACK1-binding site was further mapped; peptides beta C2-1 (beta PKC(209-216), beta C2-2 (beta PKC(186-198)), and beta C2-4 (beta PKC(218-226), but not a number of control peptides, bound to RACK1 and inhibited the C2 fragment binding to RACK1. Peptides beta C2-1, beta C2-2, and beta C2-4 specifically inhibited phorbol ester-induced translocation of the C2-containing isozymes in cardiac myocytes and insulin-induced beta PKC translocation and function in Xenopus oocytes. Therefore, peptides corresponding to amino acids 186-198, and 209-226 within the C2 region of the beta PKC are specific inhibitors for functions mediated by beta PKC.

Five unique compounds: xyloketals from mangrove fungus Xylaria sp. from the South China Sea coast

Five unique metabolites, xyloketals A (1), B (2), C (3), D (4), and E (5), and the known 6 were isolated from mangrove fungus Xylaria sp. (no. 2508), obtained from the South China Sea. The structures of these compounds were elucidated by spectroscopic and X-ray diffraction experiments. Xyloketal A is a ketal compound with a C(3) symmetry and xyloketals B-E are its analogues. It was found that xytoketal C slowly rearranged to xytoketal B in DMSO-d(6)() solution at room temperature. Xyloketal A exhibited the activity of inhibiting acetylcholine esterase.

Nicotine acts as a pharmacological chaperone to up-regulate human alpha4beta2 acetylcholine receptors

Human neuronal nicotinic acetylcholine receptor (AChR) alpha4 subunits and an alpha4 mutant (S247Falpha4) found in autosomal-dominant nocturnal frontal lobe epilepsy (ADNFLE) were expressed along with beta2 in permanently transfected tsA201 human embryonic kidney cell lines. Their sensitivity to activation, desensitization, and up-regulation by cholinergic ligands was investigated. Up-regulation after 3 to 24 h resulted primarily from an increase in assembly of AChRs from large pools of unassembled subunits, but up-regulation also resulted from a 5-fold increase in the lifetime of AChRs in the surface membrane. Up-regulation does not require current flow through surface membrane AChRs, because up-regulation occurs in the presence of the channel blocker mecamylamine and with the alpha4 mutant, which prevents nearly all AChR function. Both membrane-permeable ligands like nicotine and much less permeable quaternary amine cholinergic ligands can act as pharmacological chaperones within the endoplasmatic reticulum to promote the assembly of AChRs. Agonists are more potent pharmacological chaperones than antagonists, presumably because activated or desensitized conformations assemble more efficiently. Assembly intermediates are disrupted by solubilization in Triton X-100, but chemical cross-linking stabilizes a putative assembly intermediate approximately the size of an alpha4beta2alpha4beta2 tetramer.

A comparison of batch effect removal methods for enhancement of prediction performance using MAQC-II microarray gene expression data

Batch effects are the systematic non-biological differences between batches (groups) of samples in microarray experiments due to various causes such as differences in sample preparation and hybridization protocols. Previous work focused mainly on the development of methods for effective batch effects removal. However, their impact on cross-batch prediction performance, which is one of the most important goals in microarray-based applications, has not been addressed. This paper uses a broad selection of data sets from the Microarray Quality Control Phase II (MAQC-II) effort, generated on three microarray platforms with different causes of batch effects to assess the efficacy of their removal. Two data sets from cross-tissue and cross-platform experiments are also included. Of the 120 cases studied using Support vector machines (SVM) and K nearest neighbors (KNN) as classifiers and Matthews correlation coefficient (MCC) as performance metric, we find that Ratio-G, Ratio-A, EJLR, mean-centering and standardization methods perform better or equivalent to no batch effect removal in 89, 85, 83, 79 and 75% of the cases, respectively, suggesting that the application of these methods is generally advisable and ratio-based methods are preferred.

Substrate-induced magnetic ordering and switching of iron porphyrin molecules

To realize molecular spintronic devices, it is important to externally control the magnetization of a molecular magnet. One class of materials particularly promising as building blocks for molecular electronic devices is the paramagnetic porphyrin molecule in contact with a metallic substrate. Here, we study the structural orientation and the magnetic coupling of in-situ-sublimated Fe porphyrin molecules on ferromagnetic Ni and Co films on Cu(100). Our studies involve X-ray absorption spectroscopy and X-ray magnetic circular dichroism experiments. In a combined experimental and computational study we demonstrate that owing to an indirect, superexchange interaction between Fe atoms in the molecules and atoms in the substrate (Co or Ni) the paramagnetic molecules can be made to order ferromagnetically. The Fe magnetic moment can be rotated along directions in plane as well as out of plane by a magnetization reversal of the substrate, thereby opening up an avenue for spin-dependent molecular electronics.

Tests of General Relativity with GW150914

The LIGO detection of GW150914 provides an unprecedented opportunity to study the two-body motion of a compact-object binary in the large-velocity, highly nonlinear regime, and to witness the final merger of the binary and the excitation of uniquely relativistic modes of the gravitational field. We carry out several investigations to determine whether GW150914 is consistent with a binary black-hole merger in general relativity. We find that the final remnant's mass and spin, as determined from the low-frequency (inspiral) and high-frequency (postinspiral) phases of the signal, are mutually consistent with the binary black-hole solution in general relativity. Furthermore, the data following the peak of GW150914 are consistent with the least-damped quasinormal mode inferred from the mass and spin of the remnant black hole. By using waveform models that allow for parametrized general-relativity violations during the inspiral and merger phases, we perform quantitative tests on the gravitational-wave phase in the dynamical regime and we determine the first empirical bounds on several high-order post-Newtonian coefficients. We constrain the graviton Compton wavelength, assuming that gravitons are dispersed in vacuum in the same way as particles with mass, obtaining a 90%-confidence lower bound of 10^{13}  km. In conclusion, within our statistical uncertainties, we find no evidence for violations of general relativity in the genuinely strong-field regime of gravity.

Tumors promote altered maturation and early apoptosis of monocyte-derived dendritic cells

Tumors produce a number of immunosuppressive factors that block the maturation of CD34+ stem cells into dendritic cells (DC). We hypothesized that tumors might also interfere with the maturation and/or function of human monocyte-derived DC. In contrast to stem cells, we found that CD14+ cells responded to tumor culture supernatant (TSN) by increasing expression of APC surface markers, up-regulating nuclear translocation of RelB, and developing allostimulatory activity. Although displaying these characteristics of mature DC, TSN-exposed DC lacked the capacity to produce IL-12, did not acquire full allostimulatory activity, and rapidly underwent apoptosis. The effects of TSN appeared to be specific for maturing DC, and were not reversed by Abs against known DC regulatory factors including IL-10, vascular endothelial growth factor, TGF-beta, or PGE2. Supernatants collected from nonmalignant cell sources had no effect on DC maturation. The altered maturation and early apoptosis of monocyte-derived DC may represent another mechanism by which tumors evade immune detection.

Nongenetic mouse models of non-insulin-dependent diabetes mellitus

The purpose of the study was to develop a mouse model of non-insulin-dependent diabetes mellitus (NIDDM) that closely simulates the metabolic abnormalities of the human disease and is also cost-effective compared with the genetic models currently available. For this purpose, insulin resistance was induced in male C57BL/6J or Institute of Cancer Research (ICR) mice by feeding diets enriched in either fructose or fat, and hyperglycemia was induced by injecting these mice with a dose of streptozotocin (STZ) that does not cause diabetes in chow-fed mice. In the case of C57BL/6J mice, insulin levels initially increased in response to the fructose- and fat-enriched diets and then decreased to levels comparable to or still higher than those in chow-fed mice following STZ injection. Associated with the decrease in insulin levels following STZ, fat-fed and fructose-fed C57BL/6J mice became significantly hyperglycemic, reaching values of 388 +/- 38 and 366 +/- 58 mg/dL, respectively. In contrast, neither plasma glucose nor insulin concentrations changed in chow-fed mice injected with an identical amount of STZ. Essentially identical findings were seen before and after STZ injection in fat-fed compared with chow-fed ICR mice. Although a direct comparison was not made, sensitivity to the diabetogenic effects of STZ appeared to be greater in fat-fed ICR compared with fat-fed C57BL/6J mice. Finally, plasma glucose decreased when mice with these experimental models of NIDDM were treated with either metformin or tolbutamide. Given these results, it seems reasonable to suggest that the combination of dietary-induced insulin resistance and relatively low-dose STZ results in mouse models that should be of use in studying the pathophysiology of NIDDM or in evaluating therapeutic compounds for the treatment of NIDDM.

COVID-19 in patients with lung cancer

BACKGROUND

Patients with lung cancers may have disproportionately severe coronavirus disease 2019 (COVID-19) outcomes. Understanding the patient-specific and cancer-specific features that impact the severity of COVID-19 may inform optimal cancer care during this pandemic.

PATIENTS AND METHODS

We examined consecutive patients with lung cancer and confirmed diagnosis of COVID-19 (n = 102) at a single center from 12 March 2020 to 6 May 2020. Thresholds of severity were defined a priori as hospitalization, intensive care unit/intubation/do not intubate ([ICU/intubation/DNI] a composite metric of severe disease), or death. Recovery was defined as >14 days from COVID-19 test and >3 days since symptom resolution. Human leukocyte antigen (HLA) alleles were inferred from MSK-IMPACT (n = 46) and compared with controls with lung cancer and no known non-COVID-19 (n = 5166).

RESULTS

COVID-19 was severe in patients with lung cancer (62% hospitalized, 25% died). Although severe, COVID-19 accounted for a minority of overall lung cancer deaths during the pandemic (11% overall). Determinants of COVID-19 severity were largely patient-specific features, including smoking status and chronic obstructive pulmonary disease [odds ratio for severe COVID-19 2.9, 95% confidence interval 1.07-9.44 comparing the median (23.5 pack-years) to never-smoker and 3.87, 95% confidence interval 1.35-9.68, respectively]. Cancer-specific features, including prior thoracic surgery/radiation and recent systemic therapies did not impact severity. Human leukocyte antigen supertypes were generally similar in mild or severe cases of COVID-19 compared with non-COVID-19 controls. Most patients recovered from COVID-19, including 25% patients initially requiring intubation. Among hospitalized patients, hydroxychloroquine did not improve COVID-19 outcomes.

CONCLUSION

COVID-19 is associated with high burden of severity in patients with lung cancer. Patient-specific features, rather than cancer-specific features or treatments, are the greatest determinants of severity.

Secondary lymphoid tissue chemokine mediates T cell-dependent antitumor responses in vivo

Secondary lymphoid tissue chemokine (SLC, also referred to as Exodus 2 or 6Ckine) is a recently identified high endothelial-derived CC chemokine. The ability of SLC to chemoattract both Th1 lymphocytes and dendritic cells formed the rationale to evaluate this chemokine in cancer immunotherapy. Intratumoral injection of recombinant SLC evidenced potent antitumor responses and led to complete tumor eradication in 40% of treated mice. SLC-mediated antitumor responses were lymphocyte dependent as evidenced by the fact that this therapy did not alter tumor growth in SCID mice. Studies performed in CD4 and CD8 knockout mice also revealed a requirement for both CD4 and CD8 lymphocyte subsets for SLC-mediated tumor regression. In immunocompetent mice, intratumoral SLC injection led to a significant increase in CD4 and CD8 T lymphocytes and dendritic cells, infiltrating both the tumor and the draining lymph nodes. These cell infiltrates were accompanied by the enhanced elaboration of Th1 cytokines and chemokines monokine induced by IFN-gamma and IFN-gamma-inducible protein 10 but a concomitant decrease in immunosuppressive cytokines at the tumor site. In response to irradiated autologous tumor, splenic and lymph node-derived cells from SLC-treated tumor-bearing mice secreted significantly more IFN-gamma, GM-CSF, and IL-12 and reduced levels of IL-10 than did diluent-treated tumor-bearing mice. After stimulation with irradiated autologous tumor, lymph node-derived lymphocytes from SLC-treated tumor-bearing mice demonstrated enhanced cytolytic capacity, suggesting the generation of systemic immune responses. These findings provide a strong rationale for further evaluation of SLC in tumor immunity and its use in cancer immunotherapy.

Design and synthesis of [111In]DTPA-folate for use as a tumor-targeted radiopharmaceutical

Folate-conjugated metal chelates have been proposed as potential imaging agents for cancers that overexpress folate receptors. In a previous study, folic acid was linked through its gamma-carboxyl group to deferoxamine (DF), and the 67Ga-labeled complex ([67Ga]DF-folate) was examined for in vivo tumor targeting efficiency in athymic mice with a human tumor cell implant. Although superb tumor-to-background contrast was obtained, slow hepatobiliary clearance would compromise imaging of abdominal tumors such as ovarian cancer. In the present study, folic acid was conjugated to an alternative chelator, diethylenetriaminepentaacetic acid (DTPA), via an ethylenediamine spacer. The desired DTPA-folate (gamma) regioisomer was synthesized by two different approaches, purified by reversed phase column chromatography, and characterized mainly by analytical HPLC, mass spectroscopy, and NMR. In cultured tumor cells, uptake of [111In]DTPA-folate (gamma) was found to be specific for folate receptor-bearing cells, and the kinetics of uptake were similar to those of free folate and other folate-conjugated molecules. In the normal rat, intravenously administered [111In]DTPA-folate (gamma) was found to be rapidly excreted into the urine, giving intestinal levels of radiotracer 10-fold lower than those observed with [67Ga]DF-folate (gamma) at 4 h. In a preliminary mouse imaging study, a folate receptor-positive KB cell tumor was readily visualized by gamma scintigraphy 1 h following intravenous administration of [111In]DTPA-folate (gamma).

Denitrification and N2O:N2 production in temperate grasslands: processes, measurements, modelling and mitigating negative impacts

In this review we explore the biotic transformations of nitrogenous compounds that occur during denitrification, and the factors that influence denitrifier populations and enzyme activities, and hence, affect the production of nitrous oxide (N2O) and dinitrogen (N2) in soils. Characteristics of the genes related to denitrification are also presented. Denitrification is discussed with particular emphasis on nitrogen (N) inputs and dynamics within grasslands, and their impacts on the key soil variables and processes regulating denitrification and related gaseous N2O and N2 emissions. Factors affecting denitrification include soil N, carbon (C), pH, temperature, oxygen supply and water content. We understand that the N2O:N2 production ratio responds to the changes in these factors. Increased soil N supply, decreased soil pH, C availability and water content generally increase N2O:N2 ratio. The review also covers approaches to identify and quantify denitrification, including acetylene inhibition, (15)N tracer and direct N2 quantification techniques. We also outline the importance of emerging molecular techniques to assess gene diversity and reveal enzymes that consume N2O during denitrification and the factors affecting their activities and consider a process-based approach that can be used to quantify the N2O:N2 product ratio and N2O emissions with known levels of uncertainty in soils. Finally, we explore strategies to reduce the N2O:N2 product ratio during denitrification to mitigate N2O emissions. Future research needs to focus on evaluating the N2O-reducing ability of the denitrifiers to accelerate the conversion of N2O to N2 and the reduction of N2O:N2 ratio during denitrification.