Political stability as a major determinant of the Covid-19 pandemic outcomes.

This paper explores the role of political stability in explaining the cross-country variation of Covid-19 pandemic outcomes. Based on the international evidence, we find that lower pre-Covid-19 levels of political stability are associated with worse Covid-19 pandemic outcomes. Politically unstable countries are more likely to suffered significantly higher morbidity and mortality. Further analysis shows that political stability only matters in countries prepared with requisite medical capacity to deal with health emergencies. We also find that political stability is more crucial in countries with higher poverty rates. Overall, to combat Covid-19 and the subsequential collective threats successfully, the national authorities should pay more attention to maintain political stability.

Highly selective monoclonal antibody-based lateral flow immunoassay for visual and sensitive determination of conazole fungicides propiconazole in vegetables.

The conazole fungicide propiconazole is frequently found in vegetables although usage is not allowed. To overcome the high-cost and time-consuming labour requirements of instrumental methods, we developed a simple and visual lateral flow immunoassay for the sensitive determination of propiconazole. A hapten was carefully designed to raise a monoclonal antibody against propiconazole. Bal b/c mice were immunised with the hapten-carrier protein conjugate and a specific monoclonal antibody (mAb) was produced. Based on this mAb, a sensitive immunochromatographic strip assay (ICA) was established for rapid screening of propiconazole in vegetable samples. After optimisation of analytical parameters, the ICA strip showed a detection limit of 0.13 ng g-1 and a linear range from 0.5 to 80 ng g-1 using a strip reader. The assay also can be read by the naked eye with a visual limit of detection of 80 ng g-1. The recoveries for spiked vegetable samples by ICA ranged from 85.2% to 114.9%, with a coefficient of variation less than 11.7%. The assay time is within 45 min for a single sample including the sample pre-treatment. For spiked and blind samples, the detection capability of ICA was equivalent to liquid chromatography-mass spectrometry.

Transcriptional Regulation of PLETHORA1 in the Root Meristem Through an Importin and Its Two Antagonistic Cargos.

Plant roots are sustained through meristem activity at the root tip. Two transcriptional pathways, one mediated by PLETHORAs (PLTs) and the other by SHORTROOT and SCARECROW, play major roles in root meristem development. The role of PLTs during root meristem development requires a concentration gradient, which is not only contributed by posttranslational regulation such as growth dilution and intercellular movement but also likely by a largely unknown fine-tuned transcriptional regulatory mechanism. We report here that Arabidopsis (Arabidopsis thaliana) JANUS positively regulates PLT1 expression in the root meristem by recruiting RNA polymerase II (Pol II) to PLT1 and by interacting with PLT1. JANUS-dependent recruitment of Pol II is inhibited through the competitive binding of JANUS by GRF-INTERACTING FACTOR1 (GIF1)/ANGUSTIFOLIA3, a transcriptional cofactor that negatively regulates PLT1 expression. Finally, GIF1 and JANUS, the antagonistic regulators of PLT1, both depend on Arabidopsis IMPORTIN ß4 for their nuclear accumulation. The combination of an importin and its two antagonistic cargos in PLT1 transcription may have logistic benefits in fine-tuning the transcription of PLT1 in root meristem.

The role of time delays in P53 gene regulatory network stimulated by growth factor.

In this paper, a delayed mathematical model for the P53-Mdm2 network is developed. The P53-Mdm2 network we study is triggered by growth factor instead of DNA damage and the amount of DNA damage is regarded as zero. We study the influences of time delays, growth factor and other important chemical reaction rates on the dynamic behaviors in the system. It is shown that the time delay is a critical factor and its length determines the period, amplitude and stability of the P53 oscillation. Furthermore, as for some important chemical reaction rates, we also obtain some interesting results through numerical simulation. Especially, S (growth factor), k3 (rate constant for Mdm2p dephosphorylation), k10 (basal expression of PTEN) and k14 (Rate constant for PTEN-induced Akt dephosphorylation) could undermine the dynamic behavior of the system in different degree. These findings are expected to understand the mechanisms of action of several carcinogenic and tumor suppressor factors in humans under normal conditions.

Arabidopsis KETCH1 Is Critical for the Nuclear Accumulation of Ribosomal Proteins and Gametogenesis.

Male and female gametophytes are generated from micro- or megaspore mother cells through consecutive meiotic and mitotic cell divisions. Defects in these divisions often result in gametophytic lethality. Gametophytic lethality was also reported when genes encoding ribosome-related proteins were mutated. Although numerous ribosomal proteins (RPs) have been identified in plants based on homology with their yeast and metazoan counterparts, how RPs are regulated, e.g., through dynamic subcellular targeting, is unknown. We report here that an Arabidopsis (Arabidopsis thaliana) importin ß, KETCH1 (karyopherin enabling the transport of the cytoplasmic HYL1), is critical for gametogenesis. Karyopherins are molecular chaperones mediating nucleocytoplasmic protein transport. However, the role of KETCH1 during gametogenesis is independent of HYPONASTIC LEAVES 1 (HYL1), a previously reported KETCH1 cargo. Instead, KETCH1 interacts with several RPs and is critical for the nuclear accumulation of RPL27a, whose mutations caused similar gametophytic defects. We further showed that knocking down KETCH1 caused reduced ribosome biogenesis and translational capacity, which may trigger the arrest of mitotic cell cycle progression and lead to gametophytic lethality.

Concurrent Hearing and Genetic Screening of 180,469 Neonates with Follow-up in Beijing, China.

Concurrent hearing and genetic screening of newborns is expected to play important roles not only in early detection and diagnosis of congenital deafness, which triggers intervention, but also in predicting late-onset and progressive hearing loss and identifying individuals who are at risk of drug-induced HL. Concurrent hearing and genetic screening in the whole newborn population in Beijing was launched in January 2012. This study included 180,469 infants born in Beijing between April 2013 and March 2014, with last follow-up on February 24, 2018. Hearing screening was performed using transiently evoked otoacoustic emission (TEOAE) and automated auditory brainstem response (AABR). For genetic testing, dried blood spots were collected and nine variants in four genes, GJB2, SLC26A4, mtDNA 12S rRNA, and GJB3, were screened using a DNA microarray platform. Of the 180,469 infants, 1,915 (1.061%) were referred bilaterally or unilaterally for hearing screening; 8,136 (4.508%) were positive for genetic screening (heterozygote, homozygote, or compound heterozygote and mtDNA homoplasmy or heteroplasmy), among whom 7,896 (4.375%) passed hearing screening. Forty (0.022%) infants carried two variants in GJB2 or SLC26A4 (homozygote or compound heterozygote) and 10 of those infants passed newborn hearing screening. In total, 409 (0.227%) infants carried the mtDNA 12S rRNA variant (m.1555A>G or m.1494C>T), and 405 of them passed newborn hearing screening. In this cohort study, 25% of infants with pathogenic combinations of GJB2 or SLC26A4 variants and 99% of infants with an m.1555A>G or m.1494C>T variant passed routine newborn hearing screening, indicating that concurrent screening provides a more comprehensive approach for management of congenital deafness and prevention of ototoxicity.

Arabidopsis JANUS Regulates Embryonic Pattern Formation through Pol II-Mediated Transcription of WOX2 and PIN7.

Embryonic pattern formation relies on positional coordination of cell division and specification. Early axis formation during Arabidopsis embryogenesis requires WUSCHEL RELATED HOMEOBOX (WOX)-mediated transcription activation and PIN-FORMED7 (PIN7)-mediated auxin asymmetry. How these events are regulated is obscure. We report that Arabidopsis JANUS, a putative subunit of spliceosome, is essential for embryonic pattern formation. Significantly reduced transcription but not mRNA processing of WOX2 and PIN7 in janus suggested its role in transcriptional regulation. JANUS interacts with RNA polymerase II (Pol II) through a region outside of its spliceosome-association domain. We further show that Pol II mediates the transcription of WOX2 and PIN7 in a JANUS-dependent way and is essential for embryonic pattern formation. These findings reveal that JANUS recruits Pol II for the activation of two parallel pathways to ensure proper pattern formation during embryogenesis.

Long-term follow-up of auditory performance and speech perception and effects of age on cochlear implantation in children with pre-lingual deafness.

BACKGROUND: The development of auditory and speech perception ability of children with hearing loss is affected by many factors after they undergo cochlear implantation (CI). Age at CI (CI age) appears to play an important role among these factors. This study aimed to evaluate the development of auditory and speech perception ability and explore the impact of CI age on children with pre-lingual deafness present before 3 years of age. METHODS: Two hundred and seventy-eight children with pre-lingual deafness (176 boys and 102 girls) were included in this study, and the CI age ranged from 6 to 36 months (mean age, 19 months). Categorical auditory performance (CAP) was assessed to evaluate auditory ability, and the speech intelligibility rating was used to evaluate speech intelligibility. The evaluations were performed before CI and 1, 3, 6, 12, 18, 24, 36, 48, and 60 months after CI. RESULTS: The auditory ability of the pre-lingually hearing-impaired children showed the fastest development within 6 months after CI (k = 0.524, t = 30.992, P < 0.05); then, the progress started to decelerate (k = 0.14, t = 3.704, P < 0.05) and entered a plateau at the 24th month (k = 0.03, t = 1.908, P < 0.05). Speech intelligibility showed the fastest improvement between the 12th and 24th months after CI (k = 0.138, t = 5.365, P < 0.05); then, the progress started to decelerate (k = 0.026, t = 1.465, P < 0.05) and entered a plateau at the 48th month (k = 0.012, t = 1.542, P < 0.05). The CI age had no statistical significant effect on the auditory and speech abilities starting at 2 years after CI (P > 0.05). The optimal cutoff age for CI was 15 months. CONCLUSIONS: Within 5 years after CI, the auditory and speech ability of young hearing-impaired children continuously improved, although speech development lagged behind that of hearing. An earlier CI age is recommended; the optimal cutoff age for CI is at 15 months.

Importin ß4 Mediates Nuclear Import of GRF-Interacting Factors to Control Ovule Development in Arabidopsis.

Ovule development is critical for seed development and plant reproduction. Multiple transcription factors (TFs) have been reported to mediate ovule development. However, it is not clear which intracellular components regulate these TFs during ovule development. After their synthesis, TFs are transported into the nucleus a process regulated by karyopherins commonly known as importin alpha and ß. Around half of Arabidopsis (Arabidopsis thaliana) importin ß-coding genes have been functionally characterized but only two with specific cargos have been identified. We report here that Arabidopsis IMPORTIN ß4 (IMB4) regulates ovule development through nucleocytoplasmic transport of transcriptional coactivator growth regulating factors-interacting factors (GIFs). Mutations in IMB4 impaired ovule development by affecting integument growth. imb4 mutants were also defective in embryo sac development, leading to partial female sterility. IMB4 directly interacts with GIFs and is critical for the nucleocytoplasmic transport of GIF1. Finally, functional loss of GIFs resulted in ovule defects similar to those in imb4 mutants, whereas enhanced expression of GIF1 partially restored the fertility of imb4 The results presented here uncover a novel genetic pathway regulating ovule development and reveal the upstream regulator of GIFs.

[Correlation of single nucleotide polymorphisms rs995030 and rs4474514 of the KITLG gene with male infertility].

OBJECTIVE: To investigate the correlation of the single nucleotide polymorphisms rs995030 and rs4474514 of the tyrosine kinase receptor-specific ligand (KITLG) gene with the risk of male infertility. METHODS: This study included 360 patients with idiopathic male infertility and 338 healthy fathers as controls, all from the surrounding areas of Nanjing. According to the 5th edition of the WHO Laboratory Manual for the Examination and Processing of Human Semen, we divided the infertility patients into an azoospermia (n = 143), a severe oligozoospermia (n = 159), and an oligozoospermia group (n = 58). We obtained the basic clinical data on all the subjects, collected genomic DNA from the peripheral blood of the patients, determined the genotypes of the KITLG gene rs995030 and rs4474514 by sequence mass-array, and analyzed the correlation between the two-point gene polymorphism and male infertility by logistic regression analysis. RESULTS: Statistically significant differences were observed between the infertility patients and normal fertile controls in sperm concentration (ï¼»13.23 ± 24.52ï¼½ vs ï¼»78.74 ± 61.25ï¼½ ×106/ml, P < 0.01), the percentage of progressively mobile sperm (ï¼»18.71 ± 15.19ï¼½% vs ï¼»39.36 ± 9.75ï¼½%, P < 0.01), and the level of FSH (ï¼»16.09 ± 17.31ï¼½ vs ï¼»4.56 ± 2.41ï¼½ IU/L, P < 0.01), but not between the genotypes and male infertility, and no correlation was found in subgroup analysis. CONCLUSIONS: The single nucleotide polymorphisms rs995030 and rs4474514 of the KITLG gene were not significantly correlated with male infertility, which is to be further verified by more studies with samples of larger size and expanded selection range.

[Correlation of the single nucleotide polymorphism rs662 of PON1 with the risk of male infertility].

Objective: To investigate the correlation between the single nucleotide polymorphism (SNP) rs662 of the paraoxonase 1 gene (PON1) and the risk of male infertility. METHODS: This case-control study included 403 male idiopathic infertility patients aged 29.00 ± 4.48 years in the case group and 329 normal fertile men aged 28.28 ± 4.08 years as healthy controls. We obtained DNA from the peripheral venous blood of the subjects, genotyped the SNP rs662 of PON1 by Sequenom MassArray, and analyzed the association between different genotypes of PON1 rs662 and male infertility using the logistic regression model. RESULTS: Compared with the normal controls, the infertility patients showed a significantly increased level of follicle-stimulating hormone (FSH) (ï¼»16.30 ± 17.76ï¼½ vs ï¼»4.72 ± 2.51ï¼½ U/L, P < 0.01) but a decreased percentage of progressively motile sperm (PMS) (ï¼»7.40 ± 14.17ï¼½ % vs ï¼»41.93 ± 9.06ï¼½ %, P < 0.01) and sperm concentration (ï¼»2.74 ± 3.64ï¼½ vs ï¼»75.83 ± 63.66ï¼½ ×106/ml, P < 0.01). Statistically significant differences were not found in the other parameters between the two groups of subjects, nor in the correlation of male infertility with the heterozygous genotype GA versus the wild homozygous genotype GG (OR = 0.98, 95% CI: 0.63－1.53, P = 0.923) or the homozygous genotype AA versus the wild homozygous genotype GG (OR = 0.87, 95% CI: 0.56－1.34, P = 0.525). CONCLUSIONS: The SNP rs662 of PON1 was not correlated with male infertility, which, however, needs to be confirmed by further studies with larger samples from a larger area.

AP1G mediates vacuolar acidification during synergid-controlled pollen tube reception.

Double fertilization in angiosperms requires the delivery of immotile sperm through pollen tubes, which enter embryo sacs to initiate synergid degeneration and to discharge. This fascinating process, called pollen tube reception, involves extensive communications between pollen tubes and synergids, within which few intracellular regulators involved have been revealed. Here, we report that vacuolar acidification in synergids mediated by AP1G and V-ATPases might be critical for pollen tube reception. Functional loss of AP1G or VHA-A, encoding the γ subunit of adaptor protein 1 or the shared component of two endomembrane V-ATPases, respectively, impaired synergid-controlled pollen tube reception and caused partial female sterility. AP1G works in parallel to the plasma membrane-associated receptor FERONIA in synergids, suggesting that synergid-mediated pollen tube reception requires proper sorting of vacuolar cargos by AP1G. Although AP1G did not mediate the targeting of V-ATPases, AP1G loss of function or the expression of AP1G-RNAi compromised vacuolar acidification mediated by V-ATPases, implying their genetic interaction. We propose that vacuolar acidification might represent a distinct cell-death mechanism specifically adopted by the plant phylum, which is critical for synergid degeneration during pollen tube reception.

Arabidopsis adaptor protein 1G is critical for pollen development.

Pollen development is a pre-requisite for sexual reproduction of angiosperms, during which various cellular activities are involved. Pollen development accompanies dynamic remodeling of vacuoles through fission and fusion, disruption of which often compromises pollen viability. We previously reported that the Y subunit of adaptor protein 1 (AP1G) mediates synergid degeneration during pollen tube reception. Here, we demonstrate that AP1G is essential for pollen development. AP1G loss-of-function resulted in male gametophytic lethality due to defective pollen development. By ultrastructural analysis and fluorescence labeling, we demonstrate that AP1G loss-of-function compromised dynamic vacuolar remodeling during pollen development and impaired vacuolar acidification of pollen. Results presented here support a key role of vacuoles in gametophytic pollen development.

HAPLESS13-Mediated Trafficking of STRUBBELIG Is Critical for Ovule Development in Arabidopsis.

Planar morphogenesis, a distinct feature of multicellular organisms, is crucial for the development of ovule, progenitor of seeds. Both receptor-like kinases (RLKs) such as STRUBBELIG (SUB) and auxin gradient mediated by PIN-FORMED1 (PIN1) play instructive roles in this process. Fine-tuned intercellular communications between different cell layers during ovule development demands dynamic membrane distribution of these cell-surface proteins, presumably through vesicle-mediated sorting. However, the way it's achieved and the trafficking routes involved are obscure. We report that HAPLESS13 (HAP13)-mediated trafficking of SUB is critical for ovule development. HAP13 encodes the µ subunit of adaptor protein 1 (AP1) that mediates protein sorting at the trans-Golgi network/early endosome (TGN/EE). The HAP13 mutant, hap13-1, is defective in outer integument growth, resulting in exposed nucellus accompanied with impaired pollen tube guidance and reception. SUB is mis-targeted in hap13-1. However, unlike that of PIN2, the distribution of PIN1 is independent of HAP13. Genetic interference of exocytic trafficking at the TGN/EE by specifically downregulating HAP13 phenocopied the defects of hap13-1 in SUB targeting and ovule development, supporting a key role of sporophytically expressed SUB in instructing female gametogenesis.

The combination of decoy receptor 3 and soluble triggering receptor expressed on myeloid cells-1 for the diagnosis of nosocomial bacterial meningitis.

BACKGROUND: Early diagnosis and appropriate antibiotic treatment can significantly reduce mortality of nosocomial bacterial meningitis. However, it is a challenge for clinicians to make an accurate and rapid diagnosis of bacterial meningitis. This study aimed at determining whether combined biomarkers can provide a useful tool for the diagnosis of bacterial meningitis. METHODS: A retrospective study was carried out. Cerebrospinal fluid (CSF) levels of decoy receptor 3 (DcR3) and soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) were detected by enzyme-linked immunosorbent assay (ELISA). RESULTS: The patients with bacterial meningitis had significantly elevated levels of the above mentioned biomarkers. The two biomarkers were all risk factors with bacterial meningitis. The biomarkers were constructed into a "bioscore". The discriminative performance of the bioscore was better than that of each biomarker, with an area under the receiver operating characteristic (ROC) curve (AUC) of 0.842 (95% confidence intervals (CI) 0.770-0.914; p< 0.001). CONCLUSIONS: Combined measurement of CSF DcR3 and sTREM-1 concentrations improved the prediction of nosocomial bacterial meningitis. The combined strategy is of interest and the validation of that improvement needs further studies.

Predictive value of decoy receptor 3 in postoperative nosocomial bacterial meningitis.

Nosocomial bacterial meningitis requires timely treatment, but what is difficult is the prompt and accurate diagnosis of this disease. The aim of this study was to assess the potential role of decoy receptor 3 (DcR3) levels in the differentiation of bacterial meningitis from non-bacterial meningitis. A total of 123 patients were recruited in this study, among them 80 patients being with bacterial meningitis and 43 patients with non-bacterial meningitis. Bacterial meningitis was confirmed by bacterial culture of cerebrospinal fluid (CSF) culture and enzyme-linked immunosorbent assay (ELISA) was used to detect the level of DcR3 in CSF. CSF levels of DcR3 were statistically significant between patients with bacterial meningitis and those with non-bacterial meningitis (p<0.001). A total of 48.75% of patients with bacterial meningitis received antibiotic>24 h before CSF sampling, which was much higher than that of non-bacterial meningitis. CSF leucocyte count yielded the highest diagnostic value, with an area under the receiver operating characteristic curve (ROC) of 0.928, followed by DcR3. At a critical value of 0.201 ng/mL for DcR3, the sensitivity and specificity were 78.75% and 81.40% respectively. DcR3 in CSF may be a valuable predictor for differentiating patients with bacterial meningitis from those with non-bacterial meningitis. Further studies are needed for the validation of this study.

[Vibrant soundbridge implantation (two cases report)].

OBJECTIVE: To investigate the effect of Vibrant Soundbridge (VSB) implantation. METHODS: In accordance with the indications for VSB implantation, surgeries were done for two patients who suffered from either a sensorineural or conductive hearing loss (microtia). Their preoperative auditory thresholds (0.5, 1, 2 and 4 kHz) were 56 dB HL and 61 dB HL. The VSB was turned on and adjusted seven weeks after surgery. RESULTS: Postoperative auditory thresholds of the two patients were improved. Their pure tone thresholds were 32 dB HL and 40 dB HL, and the respective improvement was 24 dB HL and 21 dB HL. There was no facial paralysis, vertigo and tinnitus. CONCLUSION: Patients with a sensorineural or conductive hearing loss may benefit from VSB implantation.

[Outcome of cochlear implantation in prelingual pediatric auditory neuropathy].

OBJECTIVE: To explore the electrophysiological results and rehabilitation outcome of two prelingually deafened pediatric cochlear implant patients with auditory neuropathy. METHODS: Preoperative audiological evaluation, intra-postoperative electrically evoked auditory brainstem response (EABR) and neural response telemetry (NRT) record for the two cases were conducted in Beijing Tongren Hospital. A one year follow-up was performed. Data collected before and at 6,12-month intervals after implantation were compared with that from control pediatric cochlear implant patients matched for the same duration of implant use as this two cases. RESULTS: The two children implanted had not had any postoperative medical or cochlear implant device complications. Intraoperative EABR and NRT were elicited in case 1 with unrepeatable waveforms. After 12 months of training, Case 1 had shown significant improvements in sound detection, speech perception abilities and communication skills, which was better than the control group, and the electrophysiological results became normal. Case 2 had also benefited from cochlear implantation, even though no recognizable NRT was found until he returned 12 month after the operation. CONTUSIONS: The desynchronization of auditory path had been changed after the electrical stimulation ongoing 12 months for children with auditory neuropathy. The two children had not had any complications postoperatively, and each child had shown improved listening and communication skills. Cochlear implantation could help patients with auditory neuropathy to improve their communication skill and go back to the main stream.

[Progress in researches on the relation between chronic prostatitis and cytokines].

Chronic prostatitis is a common andrologic disease. The etiology and pathogensis of the disease are not yet completely understood. This article reviews the origin and the molecular strucure of cytokines and their role in the pathogenesis of prostatitis, especially chronic nonbacterial prostatitis/chronic pelvic pain syndrome.