Rare-Earth Metal Phosphinidene Complexes: A Trip from Bridging One to Terminal One.

ConspectusAs phosphorus analogues of alkylidene (or carbene) and imido (or nitrene) complexes, phosphinidene complexes have received great attention not only for their fundamental scientific merits but also for their ability to build new phosphorus-containing molecules. A large number of phosphinidene complexes in bridging, mononuclear, or terminal coordination modes have been synthesized, and their reactivity has been extensively explored. However, the synthesis of rare-earth metal (scandium, yttrium, and lanthanide metal) phosphinidene complexes lagged behind the transition metal and actinide congeners for decades. Rare-earth metal ions are among the hardest Lewis acids, whereas phosphinidene ligands are soft Lewis bases; rare-earth metal-phosphinidene coordination is thus mismatched based on the Pearson's HSAB principle. The bridging rare-earth metal phosphinidene complexes were not reported until 2008, and the synthesis of the mononuclear and terminal species is even more challenging, which has only recently been achieved.Our group reported a bis(µ2-phosphinidene)dineodymium complex in 2008. In the following >10 years, we have been pursuing the terminal rare-earth metal phosphinidene complexes. Due to the high instability of rare-earth metal-phosphorus multiple bonds, the synthesis and stabilization of these complexes are extremely difficult. Finally, by using suitable phosphinidene ligands and supporting ligands, we obtained the first mononuclear rare-earth metal phosphinidene complex in 2018 and the first terminal rare-earth metal phosphinidene complex in 2020. In these more than ten years of research, we have also found some interesting reactivity of the rare-earth metal phosphinidene complexes. The rare-earth metal bridging phosphinidene complexes can act as two-electron reductants based on the oxidative coupling of two phosphinidene ligands into a diphosphene ligand. The mononuclear rare-earth metal phosphinidene complexes catalyze the hydrogenation of terminal alkenes under mild conditions, and the joint experimental/DFT studies indicate that the hydrogenation reaction proceeds in a 1,2-addition/elimination mechanism rather than the common σ-bond metathesis mechanism. These reactivities are new and important for the rare-earth metal complexes. In addition, the ligand design in our study may contribute to the synthesis of rare-earth metal-arsenic multiple bonding complexes and alkaline-earth metal-phosphorus multiple bonding complexes, which have not yet been realized. Herein, we present an account of our investigations into rare-earth metal phosphinidene complexes, a trip from bridging one to terminal one. To give the readers an overall image of the development of the rare-earth metal phosphinidene complexes, some findings from other researchers are also included.

Different activation of STAT1 and STAT2 phosphorylation by IFNc, IFNd, and IFNh in tilapia.

Type I IFNs are a subset of cytokines exerting their antiviral effects mainly through the JAK-STAT signalling. Immunogenetic studies have shown that fish possess key components of IFN-JAK-STAT cascade, but the information about the distinct responses of STAT1 and STAT2 to different IFNs is rather limited in fish. Here, we identified and cloned STAT1 and STAT2 genes (named as On-STAT1 and On-STAT2) from tilapia, Oreochromis niloticus. On-STAT1 and On-STAT2 genes were detected in all orangs/tissues examined, and were rapidly induced in spleen, head kidney, and liver following the stimulation of poly(I:C). In addition, the stimulation of poly(I:C), poly(A:T), and different subgroups of recombinant IFNs could induce the expression of On-STAT1 and On-STAT2 in TA-02 cells with distinct induction levels. Importantly, On-STAT2 was rapidly phosphorylated by all three subgroups of IFNs, but the phosphorylation of On-STAT1 was only observed in IFNc- and IFNh-treated TA-02 cells, reflecting the distinct activation of STAT by different subgroups of fish IFNs. The present results thus contribute to better understanding of the JAK-STAT signalling mediated by different subgroups of IFNs in fish.

Prevalence and clinical outcomes of pleural effusion in COVID-19 patients: A systematic review and meta-analysis.

Observational studies indicate that pleural effusion has an association with risk and the clinical prognosis of COVID-19 disease; however, the available literature on this area is inconsistent. The objective of this systematic review and meta-analysis is to evaluate the correlation between COVID-19 disease and pleural effusion. A rigorous literature search was conducted using multiple databases. All eligible observational studies were included from around the globe. The pooled prevalence and associated 95% confidence interval (CI) were calculated using the random effect model. Mantel-Haenszel odds ratios were produced to report overall effect size using random effect models for severity and mortality outcomes. Funnel plots, Egger regression tests, and Begg-Mazumdar's rank correlation test were used to appraise publication bias. Data from 23 studies including 6234 COVID-19 patients was obtained. The overall prevalence of pleural effusion in COVID-19 patients was 9.55% (95% CI, I2 = 92%). Our findings also indicated that the presence of pleural effusions associated with increased risk of severity of disease(OR = 5.08, 95% CI 3.14-8.22, I2 = 77.4%) and mortality due to illness(OR = 4.53, 95% CI 2.16-9.49, I2 = 66%) compared with patients without pleural effusion. Sensitivity analyses illustrated a similar effect size while decreasing the heterogeneity. No significant publication bias was evident in the meta-analysis. The presence of pleural effusion can assist as a prognostic factor to evaluate the risk of worse outcomes in COVID-19 patients hence, it is recommended that hospitalized COVID-19 patients with pleural effusion should be managed on an early basis.

Synthesis, Characterization, and Reactivity of a Hydrido- and Imido-Bridged Dinuclear Ytterbium(III) Complex.

The trivalent rare-earth metal hydrido and imido complexes are of versatile reactivity, and many such complexes have been synthesized. However, no example of a rare-earth metal complex bearing both hydrido- and imido-ligands has been reported. Herein, we report the first rare-earth metal complex bearing both hydrido- and imido-ligands, namely a hydrido- and imido-bridged dinuclear ytterbium(III) complex. The complex was synthesized via an unprecedented redox reaction of divalent rare-earth metal hydrido complex with azido compound. DFT calculation indicated that the N2 release from azido compound in the presence of ytterbium(II) is a kinetically facile process because of the cooperative effects of the two metal centers. The reactivity of the hydrido- and imido-bridged dinuclear ytterbium(III) complex was also explored, which showed the redox, addition and σ-bond metathesis reactivities.

OsLFR is essential for early endosperm and embryo development by interacting with SWI/SNF complex members in Oryza sativa.

Rice (Oryza sativa L.) endosperm provides the developing embryo with nutrients and provides human beings with a staple food. The embryo eventually develops into a new sporophyte generation. Despite their important roles, the molecular mechanisms underlying early-stage endosperm and embryo development remain elusive. Here, we established the fundamental functions of rice OsLFR, an ortholog of the Arabidopsis SWI/SNF chromatin-remodeling complex (CRC) component LFR. OsLFR was expressed primarily in the rice spikelets and seeds, and the OsLFR protein was localized to the nucleus. We conducted genetic, cellular and molecular analyses of loss-of-function mutants and transgenic rescue lines. OsLFR depletion resulted in homozygous lethality in the early seed stage through endosperm and embryo defects, which could be successfully recovered by the OsLFR genomic sequence. Cytological observations revealed that the oslfr endosperm had relatively fewer free nuclei, had abnormal and arrested cellularization, and demonstrated premature programed cell death: the embryo was reduced in size and failed to differentiate. Transcriptome profiling showed that many genes, involved in DNA replication, cell cycle, cell wall assembly and cell death, were differentially expressed in a knockout mutant of OsLFR (oslfr-1), which was consistent with the observed seed defects. Protein-protein interaction analysis showed that OsLFR physically interacts with several putative rice SWI/SNF CRC components. Our findings demonstrate that OsLFR, possibly as one component of the SWI/SNF CRC, is an essential regulator of rice seed development, and provide further insights into the regulatory mechanism of early-stage rice endosperm and embryo development.

The effect of beta-amyloid and tau protein aggregations on magnetic susceptibility of anterior hippocampal laminae in Alzheimer's diseases.

Previous studies have reported the changes of magnetic susceptibility induced by iron deposition in hippocampus of Alzheimer's disease (AD) brains. It is well-known that hippocampus is divided into well-defined laminar architecture, which, however, is difficult to be resolved with in-vivo MRI due to the limited imaging resolution. The present study aims to investigate layer-specific magnetic susceptibility in the hippocampus of AD patients using high-resolution ex-vivo MRI, and elucidate its relationship with beta amyloid (Aß) and tau protein histology. We performed quantitative susceptibility mapping (QSM) and T2* mapping on postmortem anterior hippocampus samples from four AD, four Primary Age-Related Tauopathy (PART), and three control brains. We manually segmented each sample into seven layers, including four layers in the cornu ammonis1 (CA1) and three layers in the dentate gyrus (DG), and then evaluated AD-related alterations of susceptibility and T2* values and their correlations with Aß and tau in each hippocampal layer. Specifically, we found (1) layer-specific variations of susceptibility and T2* measurements in all samples; (2) the heterogeneity of susceptibility were higher in all layers of AD patients compared with the age- and gender-matched PART cases while the heterogeneity of T2* values were lower in four layers of CA1; and (3) voxel-wise MRI-histological correlation revealed both susceptibility and T2* values in the stratum molecular (SM) and stratum lacunosum (SL) layers were correlated with the Aß content in AD, while the T2* values in the stratum radiatum (SR) layer were correlated with the tau content in the PART but not AD. These findings suggest a selective effect of the Aß- and tau-pathology on the susceptibility and T2* values in the different layers of anterior hippocampus. Particularly, the alterations of magnetic susceptibility in the SM and SL layers may be associated with Aß aggregation, while those in the SR layermay reflect the age-related tau protein aggregation.

Chemical exchange saturation transfer imaging for epilepsy secondary to tuberous sclerosis complex at 3 T: Optimization and analysis.

The homeostasis of various metabolites is impaired in epilepsy secondary to the tuberous sclerosis complex (TSC). Chemical exchange saturation transfer (CEST) imaging is an emerging molecular MRI technique that can detect various metabolites and proteins in vivo. However, the role of CEST imaging for TSC-associated epilepsy has not been assessed. Here, we aim to investigate the feasibility of applying CEST imaging to TSC-associated epilepsy, optimize the CEST acquisition parameters, and provide an analysis method for exploring the dominant molecular contributors to the CEST signal measured. Nine TSC epilepsy patients were scanned on a 3-T MRI system. The CEST saturation frequencies were swept from -6 to 6 ppm with 12 different combinations of saturation power (4, 3, 2 and 1 µT) and duration (1000, 700 and 400 ms). Furthermore, a two-stage simulation method based on the seven-pool Bloch-McConnell model was proposed to assess the contribution of each exchangeable pool to the CEST signal in normal-appearing white matter and cortical tubers, which avoided the complexity and uncertainty of full Bloch-McConnell fitting. The results showed that under the optimal saturation duration of 1000 ms, the greatest contrast between tubers and normal tissues occurred around 3, 2.5, 1.75 and 3.5 ppm for B1 of 4, 3, 2 and 1 µT, respectively. At the optimal frequency offsets, the CEST values of tubers were significantly higher than those in the normal brain tissues (P < 0.01). Furthermore, the two-stage analysis suggested that the amine pool played a dominant role in yielding the contrast between cortical tubers and normal tissues. These results indicate that CEST MRI may serve as a potentially useful tool for identifying tubers in TSC, and the two-stage analysis method may provide a route for investigating the molecular contributions to the CEST contrast in biological tissues.

Divalent Ytterbium Hydrido Complex Supported by a ß-Diketiminato-Based Tetradentate Ligand: Synthesis, Structure, and Reactivity.

While the chemistry of trivalent rare-earth metal hydrido complexes has been well developed in the past 40 years, that of the divalent rare-earth metal hydrido complexes remains in its infancy because of the synthetic challenge of such complexes. In this paper, we report the synthesis and structural characterization of a divalent ytterbium hydrido complex supported by a bulky ß-diketiminato-based tetradentate ligand. This hydrido complex is a dimer containing two µ-hydrogen ligands, and it easily undergoes a hydrido shift reaction to form a new divalent ytterbium hydrido complex that contains only one hydrido bridge. Furthermore, this hydrido complex reacts with pyridine and pyridine derivatives, showing versatile reactivity [Yb-H addition to pyridine, hydrido shift to ancillary ligand, and ytterbium(II)-center-induced redox reaction with bipyridine]. This hydrido complex reacts with Ph3P═O, resulting in a P-CPh cleavage of Ph3P═O and an elimination of C6H6; on the other hand, the reaction with Ph3P═S is a hydrido coupling-based redox reaction. The reactions of this hydrido complex with 1 and 2 equiv of PhSSPh clearly indicate that the hydrido coupling-based redox reaction is prior to the ytterbium(II) oxidation-based redox reaction.

Myocarditis associated with Covid-19 disease: A systematic review of published case reports and case series.

BACKGROUND: Covid-19 is an extremely contagious illness caused by the severe acute respiratory syndrome (SARS-CoV-2) virus. The cardiac involvement in such a public health emergency disease has not been well studied and a conflicting evidence exists on this issue. OBJECTIVE: This systematic review article aimed to compile and illustrate clinical characteristics, diagnostic findings, management, and outcomes manifesting in myocarditis linked with Covid-19. METHODS: A literature search was accomplished for published eligible articles with MEDLINE/PubMed and Embase databases. All eligible case reports and case series were included from around the world without any language restrictions. For this review, inclusion criteria were laboratory-confirmed SARS-CoV-2 infection cases reporting a diagnosis of acute myocarditis. RESULTS: Data from 41 studies describing myocarditis in 42 Covid-19 patients was obtained. The median age of these patients was 43.4 years, with 71.4% of them being men. Fever was the most prevalent presenting symptoms seen in 57% of patients. Hypertension was the most pervasive comorbidity accompanying these patients. Cardiac biomarkers troponin and brain natriuretic peptide (BNP) were raised in almost 90% and 87% of patients, respectively. Electrocardiogram findings were nonspecific and included ST-segment and T-wave changes. Echocardiogram commonly showed left ventricular systolic dysfunction with increased heart size. Cardiac magnetic resonance imaging (CMRI) exhibited myocardial edema and injury. The most prevalent histopathological feature appreciated was diffuse lymphocytic inflammatory infiltrates. Antivirals and corticosteroids were the most frequently used medications. About 38% of patients also needed vasopressor assistance. Out of 42 patients, 67% recovered, and eight died. CONCLUSION: Because of the risk of a sudden worsening of patients conditions and myocarditis association with considerable mortality and morbidity, a knowledge of this cardiac complication of Covid-19 disease is crucial for healthcare professionals.

Crimean-Congo haemorrhagic fever-induced liver injury: A systematic review and meta-analysis.

BACKGROUND: Crimean-Congo haemorrhagic fever (CCHF) is a fatal acute tick-borne viral infection and substantial emerging global public health threat. This illness has a high case fatality rate of up to 40%. The liver is one of the important target organs of the CCHF virus. OBJECTIVE: The aim of this meta-analysis to evaluate the correlation between CCHF and liver injury and draw more generalised inferences about the abnormal serum markers of liver injury such as alanine aminotransferase (ALT), aspartate aminotransferase (AST) in CCHF patients. METHODS: A literature search was accomplished for published eligible articles with MEDLINE/PubMed and Embase databases. All eligible observational studies and case series were included from around the world. The inclusion criteria were articles describing liver injury biomarkers amongst patients diagnosed with CCHF. RESULTS: Data from 18 studies, consisting of 1238 patients with CCHF were included in this meta-analysis. Overall pooled incidence of at least one raised liver injury biomarker was 77.95% (95% CI, I2  =  88.50%, P < .0001). Similarly, pooled incidence of elevated AST and ALT was 85.92% (95% CI, I2  = 85.27%, P < .0001) and 64.30% (95% CI, I2  =  88.32%, P < .0001), respectively. Both Egger and Begg-Mazumdar's tests detected no apparent publication bias in all three meta-analyses (P > .05). CONCLUSION: Our study shows that CCHF has a very detrimental effect on liver function. Abnormal liver function may lead to poor prognosis and increased morbidity and mortality in CCHF patients. Hence, Physicians must recognise and continuously monitor these biomarkers, since these markers may aid in early stratification of prognosis and the prevention of severe outcomes in infection with such a high case fatality rate.

Risk of systemic lupus erythematosus in patients with idiopathic thrombocytopenic purpura: a population-based cohort study.

BACKGROUND: Idiopathic thrombocytopenic purpura (ITP) may play a role in early-stage systemic lupus erythematosus (SLE). The incidence of SLE in patients with ITP and the potential relationship between them is still unclear. This study was performed to provide epidemiological evidence regarding the relationship between ITP and SLE occurrence. METHODS: In this population-based retrospective cohort study, the risk of SLE was analysed in a cohort of patients newly diagnosed with ITP between 2000 and 2013. Controls were selected at a 1:2 ratio through propensity score matching (PSM) using the greedy algorithm. The Cox proportional hazard model was used to analyse the association between ITP and SLE incidence. There were four different Cox regression models, and the sensitivity analyses were implemented to evaluate the HR of SLE after exposure with ITP. RESULTS: In the age-matched and sex-matched ITP and non-ITP cohort, the average follow-up time was about 80 months in this study. There were 34 (4.70%) and 27 (0.19%) incident cases of SLE in ITP and non-ITP group. The incidence rates were 62.0 (95% CI 44.3 to 86.8) and 2.10 (95% CI 1.44 to 3.06), respectively. The adjusted HR of incidental SLE in the ITP group was 25.1 (95% CI 13.7 to 46.0). The other risk factors for SLE were female sex and Sjogren's syndrome. After PSM, the incidence rate and Kaplan-Meir curves of SLE were consistent with the results for the age-matched and sex-matched population, the HR 17.4 (95% CI 5.28 to 57.4) was estimated by conditional Cox model. CONCLUSION: This cohort study demonstrated that patients with ITP have a higher risk of SLE. Clinically, patients with ITP should be monitored for incidental lupus.

Samarium(II) Monoalkyl Complex Supported by a ß-Diketiminato-Based Tetradentate Ligand: Synthesis, Structure, and Catalytic Hydrosilylation of Internal Alkynes.

The synthesis and catalytic applications of trivalent rare-earth metal alkyl complexes have been well developed, but the chemistry of divalent rare-earth metal alkyl complexes lagged much behind. Herein, we report the synthesis, structure, and catalytic applications of a samarium(II) monoalkyl complex supported by a ß-diketiminato-based tetradentate ligand, [LSmCH(SiMe3 )2 ] (L=[MeC(NDipp)CHC(Me)NCH2 CH2 N(Me)CH2 CH2 NMe2 ]- , Dipp=2,6-(iPr)2 C6 H3 ). This complex is synthesized by the salt metathesis reaction of samarium iodide [LSm(µ-I)]2 and KCH(SiMe3 )2 in 63 % yield. Its structure is characterized by single-crystal X-ray diffraction, showing a distorted square-pyramid coordination geometry. This samarium(II) monoalkyl complex exhibits high catalytic activity in the hydrosilylation of aryl and methyl-substituted unsymmetrical internal alkynes with secondary hydrosilanes, selectively providing the α-(E) products in high yields.

[Quantitative susceptibility mapping of ultra-high resolution monkey brain in vivo at 9.4 T].

Quantitative susceptibility mapping (QSM) can provide tissue susceptibility information and has been adapted for clinical research and diagnosis. QSM of monkey brain in vivo at 9.4 T has not been demonstrated so far. In this study 9.4 T in vivo monkey brain QSM was performed with 200 µm isotropic high-resolution. It was found that the inherent singularity problem for QSM diverged significantly at ultra-high image resolution during regularization process and resulted in severe image artifacts. The K-space division (TKD) was applied to eliminate the artifacts, with an optimal threshold level between 0.2 and 0.3. High resolution QSM of monkey brain in vivo can thus provide a novel tool for brain research.

A novel strategy for real-time and in situ detection of cytochrome c and caspase-9 in Hela cells during apoptosis.

Cytochrome c (cyt c) and caspase-9 were critical biomarkers in mitochondria-mediated apoptosis. A novel electrochemical immunosensor was developed for in situ analysis of cyt c and caspase-9 in the cytosol. Gold nanoparticle-polydopamine (AuNP/PDA) composites were used to fabricate the interface of the sensor. The anti-cyt c or anti-caspase-9 functionalized-immunosensor provided a biomimetic interface for immunosensing of cyt c or caspase-9 in Hela cells during apoptosis. The changes in the expression level of cyt c and caspase-9 in the cytosol upon curcumin-induced apoptosis were detected by using the proposed method, and also the influence of different concentrations and incubation times of curcumin-induced Hela cells was investigated. This method achieved a linear range (0.1-100 µM) for standard cyt c and caspase-9, with a detection limit of 0.03 ± 0.01 µM for standard cyt c and 0.08 ± 0.02 µM for standard caspase-9. Moreover, this method was used to detect cells which could detect as low as 100 cells which expressed cyt c and caspase-9, and also the results are in good agreement with standard flow cytometry analysis. The developed electrochemical immunosensor offered a simple and rapid approach for sensitive evaluation of apoptosis markers with considerable specificity and reproducibility, and also the developed strategy could be of great importance in clinical diagnosis and therapeutic research.

Pine wilt disease detection algorithm based on improved YOLOv5.

Pine wilt disease (PWD) poses a significant threat to forests due to its high infectivity and lethality. The absence of an effective treatment underscores the importance of timely detection and isolation of infected trees for effective prevention and control. While deep learning techniques combined unmanned aerial vehicle (UAV) remote sensing images offer promise for accurate identification of diseased pine trees in their natural environments, they often demand extensive prior professional knowledge and struggle with efficiency. This paper proposes a detection model YOLOv5L-s-SimAM-ASFF, which achieves remarkable precision, maintains a lightweight structure, and facilitates real-time detection of diseased pine trees in UAV RGB images under natural conditions. This is achieved through the integration of the ShuffleNetV2 network, a simple parameter-free attention module known as SimAM, and adaptively spatial feature fusion (ASFF). The model boasts a mean average precision (mAP) of 95.64% and a recall rate of 91.28% in detecting pine wilt diseased trees, while operating at an impressive 95.70 frames per second (FPS). Furthermore, it significantly reduces model size and parameter count compared to the original YOLOv5-Lite. These findings indicate that the proposed model YOLOv5L-s-SimAM-ASFF is most suitable for real-time, high-accuracy, and lightweight detection of PWD-infected trees. This capability is crucial for precise localization and quantification of infected trees, thereby providing valuable guidance for effective management and eradication efforts.

Is intravoxel incoherent motion magnetic resonance imaging useful for predicting hepatocellular cancer recurrence and invasion of the peritumoral zone after transarterial chemoembolization?

PURPOSE: We evaluated the potential role of intravoxel incoherent motion (IVIM) in predicting the therapeutic response and peritumoral invasion in patients with hepatocellular carcinoma (HCC) treated with transarterial chemoembolization (TACE). MATERIALS AND METHODS: We enrolled 47 patients previously treated with TACE between January 2018 and December 2021. We evaluated the IVIM-derived metrics [apparent diffusion coefficient (ADC), D, D*, f] in the TACE-treated, peritumoral, and parenchymal areas of the liver. RESULTS: The ADCtace and Dtace values (1.13 ± 0.22 × 10-3 m2/s vs 0.95 ± 0.13 × 10-3 mm2/s, 1.28 ± 0.27 × 10-3 mm2/s vs 1.07 ± 0.3 × 10-3 mm2/s, P < 0.05) were higher in the non-progressing groups than in the progressing groups in the TACE-treated areas. Dpt represented the D values in the peritumoral area, which can distinguish between the progressive and non-progressive groups with an AUC of 0.73. The Dstd values, which represent the D values in the peritumoral area normalized by the D values in the liver parenchyma in the non-progressing groups (1.10 ± 0.14 × 10-3 mm2/s), were higher than those of the progressing groups (0.93 ± 0.17 × 10-3 mm2/s). CONCLUSION: The ADCtace, Dtace, Dpt, and Dstd values reflect the changes in the microstructure of the progressive and non-progressive groups after TACE treatment, showing robust diagnostic performances in predicting the therapeutic response and peritumoral invasion.

Identification and functional characterization of a long-type peptidoglycan recognition protein, PGRP-L in amphibian Xenopus laevis.

Peptidoglycan recognition proteins (PGRPs) are a family of multifunctional proteins playing vital roles in PGN metabolism and antibacterial defense, and their functions have been well-characterized in mammals, bony fishes, and insects. However, the information about the functions of amphibian long-type PGRP is rather limited. Here, we identified and cloned a long-type PGRP gene (named Xl-PGRP-L) from African clawed frog, Xenopus laevis. Xl-PGRP-L gene was detected in all orangs/tissues examined, and was rapidly induced in intestine, liver, and lung following the stimulation of PGN. Sequence analysis showed that Xl-PGRP-L possesses four Zn2+-binding residues (His358, Tyr395, His470, and Cys478) required for amidase activity of catalytic PGRPs, and assays for amidase activity revealed that recombinant Xl-PGRP-L cloud degrade PGN in a Zn2+-dependent manner, indicating that Xl-PGRP-L is belonging to catalytic PGRPs. In addition, Xl-PGRP-L have antibacterial activity against Gram-negative bacteria Edwardsiella tarda and Gram-positive bacteria Streptococcus agalactiae. The present investigation represents the first characterization regarding the biological activities of amphibian long-type PGRPs, thus contributes to a better understanding of the functions of tetrapod PGRPs and the molecular mechanisms of amphibian antibacterial defense.

Identification and functional characterization of protein kinase R (PKR) in amphibian Xenopus tropicalis.

As one of interferon-induced serine/threonine kinases, the protein kinase R (PKR) plays vital roles in antiviral defense, and functional features of PKR remain largely unknown in amphibians, which suffer from ranaviral diseases in the last few decades. In this study, a PKR gene named Xt-PKR was characterized in the Western clawed frog (Xenopus tropicalis). Xt-PKR gene was widely expressed in different organs/tissues, and was rapidly induced by poly(I:C) in spleen, kidney, and liver. Intriguingly, Xt-PKR could be up-rugulated by the treatment of type I and type III interferons, and the transcript level of Xt-PKR induced by type I interferon was much higher than that of type III interferon. Moreover, overexpression of Xt-PKR can suppress the protein synthesis and ranavirus replication in vitro, and the residue lysine required for the translation inhibition activity in mammalian PKR is conserved in Xt-PKR. The present study represents the first characterization on the functions of amphibian PKR, and reveals considerable functional conservation of PKR in early tetrapods.

T1 relaxation time analysis in predicting hepatic dysfunction and prognosis in patients with HCC undergoing transarterial chemoembolization.

OBJECTIVE: To evaluate the value of T1 mapping in predicting hepatic dysfunction and prognosis in patients with hepatocellular carcinoma (HCC) undergoing transarterial chemoembolization (TACE). MATERIAL AND METHODS: 100 consecutive patients with treatment-naive HCC treated with TACE were prospectively analyzed. Clinical, laboratory, and MRI parameters (liver and tumor T1 relaxation times (T1L, T1T)) before and/or following TACE were measured and calculated. Clinical parameters included the Child-Turcotte-Pugh (CTP) classification, Barcelona Clinic Liver Cancer Classification (BCLC) criteria, and albumin-bilirubin (ALBI) score. Laboratory parameters were the gold standard for hepatic dysfunction. T1L and T1T were combined by stepwise multivariate logistic regression to yield a T1-related probability index (T1com) for further analysis. Study endpoints included hepatic dysfunction and progression-free survival (PFS) rate. RESULTS: 38 patients (38%) were diagnosed with hepatic dysfunction following TACE. There was no significant difference in clinical parameters between the groups with and without hepatic dysfunction. Logistic regression analysis showed that T1L and T1T were independent risk factors for assessing hepatic dysfunction. T1com showed a better AUC than T1L and T1T (0.81 vs. 0.76 and 0.69, P = 0.007 and 0.006). Patients with low T1com (≤0.42) showed a better median PFS than patients with high T1com (>0.42) (167.0 vs. 215.9 days, P = 0.010). In comparison, CTP, BCLC, and ALBI scores were not statistically significant in predicting PFS in HCC patients treated with TACE (P > 0.05). CONCLUSION: Compared with widely used clinical parameters, T1 was more capable of predicting hepatic dysfunction after TACE. Stratification of patients with HCC undergoing TACE according to T1 may help clinicians to develop treatment strategies in preventing the occurrence of hepatic dysfunction and improving individual prognoses.