The Carboxyl Terminal Regions of P0 Protein Are Required for Systemic Infections of Poleroviruses.

P0 proteins encoded by poleroviruses Brassica yellows virus (BrYV) and Potato leafroll virus (PLRV) are viral suppressors of RNA silencing (VSR) involved in abolishing host RNA silencing to assist viral infection. However, other roles that P0 proteins play in virus infection remain unclear. Here, we found that C-terminal truncation of P0 resulted in compromised systemic infection of BrYV and PLRV. C-terminal truncation affected systemic but not local VSR activities of P0 proteins, but neither transient nor ectopic stably expressed VSR proteins could rescue the systemic infection of BrYV and PLRV mutants. Moreover, BrYV mutant failed to establish systemic infection in DCL2/4 RNAi or RDR6 RNAi plants, indicating that systemic infection might be independent of the VSR activity of P0. Partially rescued infection of BrYV mutant by the co-infected PLRV implied the functional conservation of P0 proteins within genus. However, although C-terminal truncation mutant of BrYV P0 showed weaker interaction with its movement protein (MP) when compared to wild-type P0, wild-type and mutant PLRV P0 showed similar interaction with its MP. In sum, our findings revealed the role of P0 in virus systemic infection and the requirement of P0 carboxyl terminal region for the infection.

Schizandrin attenuates lung lesions induced by Avian pathogenic Escherichia coli in chickens.

Avian pathogenic Escherichia coli (APEC) can cause serious pathological changes and inflammation in chickens. Schizandrin has anti-inflammatory activity and can prevent damage to various tissues and organs. The purpose of this study was to investigate the protective effect of schizandrin on APEC-induced lung lesions in chickens and explore the potential mechanism of schizandrin protection. The schizandrin (50, 100, and 200 mg/kg) was intragastrically administered for 3 days. APEC was administered using intraperitoneal (i.p.) injection to induce lung lesions. Then, chickens were sacrificed by CO2 inhalation 24 h later and the lung tissues were collected for examining histopathological changes, wet/dry (W/D) ratio, myeloperoxidase (MPO) activity, malondialdehyde (MDA), levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, IL-6, and IL-8 and activation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways. Our findings showed that schizandrin markedly inhibited pathological changes, pulmonary edema, MPO activity and MDA content. Moreover, schizandrin markedly reduced the levels of TNF-α, IL-1ß, IL-6 and IL-8 in lung tissue. Importantly, the mechanism responsible for these effects was attributed to the inhibitory effect of schizandrin on NF-κB and MAPK signaling activation. In conclusion, our findings reveal that schizandrin displays anti-oxidant and anti-inflammatory activity against APEC-induced lung lesions in chickens, paving the way for rational use of schizandrin as a protective agent against lung-related inflammatory disease.

Identification of progranulin as a novel diagnostic biomarker for early-onset sepsis in neonates.

Neonatal early-onset sepsis (EOS) is associated with high morbidity and mortality. Accurate early diagnosis is crucial for prompt treatment and a better clinical outcome. We aimed to identify new biomarkers for the diagnosis of EOS. A total of 152 neonates with a risk of EOS were divided into an EOS group and a non-EOS group according to the conventional diagnostic criteria. Blood samples were collected within 0-24, 24-48, and 48-72 h after birth. Serum levels of progranulin (PGRN), interleukin (IL)-33, IL-17a, IL-23, IL-6, tumor necrosis factors α (TNF-α), interferon γ (IFN-γ), granulocyte-macrophage colony-stimulating factor (GM-CSF), procalcitonin (PCT), and C-reactive protein (CRP) were determined. PGRN levels were significantly elevated in the EOS neonates compared with the levels in the non-EOS neonates (1.53 vs. 0.77 ng/ml (median), P < 0.001), with an area under the receiver operating characteristic (ROC) curve (AUC) of 0.76 (P < 0.001). Compared with PGRN, IL-33, IL-17a, IL-23, IL-6, PCT, and CRP showed significant (AUC > 0.70) but slightly less predictive power for EOS within the same time range. Stepwise multivariate regression analysis identified PGRN, IL-33, and PCT as independent predictors of EOS. In addition, the combined measurements of PGRN, IL-33, and PCT showed significantly higher predictive power for EOS than any of the three markers alone. PGRN showed greater efficacy for predicting EOS than the traditional markers PCT and CRP as well as other potential markers tested in this study. PGRN may serve as an effective biomarker for the early diagnosis of EOS.

[Accurate use of antibiotics for preterm infants with early-onset sepsis should be taken seriously].

At present, non-standard use of antibiotics remains a common phenomenon in the treatment of preterm infants with early-onset sepsis (EOS) in China. The expert panel of neonatologists in Hunan Province formulated a consensus on the diagnosis and use of antibiotics for EOS in preterm infant [Chin J Contemp Pediatr, 2020, 22(1): 1-6], which has a positive effect on the rational use of antibiotics. Based on this consensus, this article points out that in order to use antibiotics accurately, it is necessary to accurately identify EOS in preterm infants, accurately understand their clinical manifestations and medical history, and accurately evaluate the laboratory test results. Also, this article offers suggestions for the use of antibiotics in preterm infants with EOS.

[Predictive factors for poor prognosis of neonates with early-onset sepsis].

OBJECTIVE: To study the predictive factors for poor prognosis of neonates with early-onset sepsis (EOS). METHODS: The clinical data of 371 neonates with EOS were collected. According to prognosis, they were divided into a good prognosis group with 264 neonates and a poor prognosis group with 107 neonates. The two groups were compared in terms of perinatal conditions, clinical manifestations, laboratory markers, comorbidities, and treatment process. Multivariate logistic regression analysis was used to investigate the predictive factors for poor prognosis of EOS. RESULTS: The poor prognosis group had significantly lower birth weight and gestational age than the good prognosis group (P<0.05). Compared with the good prognosis group, the poor prognosis group had significantly higher proportions of preterm neonates, low birth weight neonates, very low birth weight neonates and twins (P<0.05), as well as a significantly higher proportion of mothers who used hormone or antibiotics before delivery (P<0.05). Compared with the good prognosis group, the poor prognosis group had significantly higher incidence rates of poor response and respiratory hypofunction (P<0.05) and a significantly lower incidence rate of jaundice (P<0.05). Compared with the good prognosis group, the poor prognosis group had significantly higher incidence rates of white blood cell count <5×109/L, platelet count <100×109/L, anemia, coagulation disorder, renal dysfunction, liver impairment, hypoproteinemia, and hypoglycemia (P<0.05). The poor prognosis group had significantly higher incidence rates of neonatal respiratory distress syndrome, pulmonary hemorrhage, necrotizing enterocolitis, intraventricular hemorrhage, brain injury, pulmonary hypertension, and shock than the good prognosis group (P<0.05). Compared with the good prognosis group, the poor prognosis group had significantly longer length of hospital stay and course of treatment with antibiotics (P<0.05) and a significantly higher proportion of neonates receiving mechanical ventilation or vasoactive agents (P<0.05). The multivariate logistic regression analysis showed that very low birth weight (OR=41.734), necrotizing enterocolitis (OR=12.669), brain injury (OR=8.372), shock (OR=5.889), mechanical ventilation (OR=5.456), and liver impairment (OR=4.075) were independent predictive factors for poor prognosis of neonates with EOS (P<0.05). CONCLUSIONS: Very low birth weight, mechanical ventilation, necrotizing enterocolitis, brain injury, shock, and liver impairment have a certain value in predicting the poor prognosis of neonates with EOS.

[Cut-off value of white blood cell count in the diagnosis of early-onset sepsis in neonates].

OBJECTIVE: To study the clinical significance and cut-off value of white blood cell (WBC) count in the diagnosis of early-onset sepsis (EOS) in neonates. METHODS: A retrospective analysis was performed on 306 neonates with EOS who were admitted from January 2019 to March 2020. A total of 580 children without infection who were admitted during the same period of time were enrolled as the control group. General status and WBC count were compared between the two groups. The diagnostic value of WBC count was analyzed based on the diagnostic and therapeutic protocol of neonatal sepsis in 2003 (referred to as the 2003 diagnostic and therapeutic protocol) and the expert consensus on the diagnosis and treatment of neonatal sepsis (2019 edition) (referred to as the 2019 expert consensus). RESULTS: According to the two different diagnosis and treatment protocols, the statistical analysis showed that WBC count had a relatively positive rate (51.3% and 32.0% respectively) but a relatively high specificity (93.3% and 98.6% respectively). The receiver operating characteristic (ROC) curve analysis showed that the area under the ROC curve of WBC count in the 2003 diagnostic and therapeutic protocol was larger than that in the 2019 expert consensus (P<0.05). CONCLUSIONS: The cut-off value of WBC ≥25×109/L in the 2003 diagnostic and therapeutic protocol is more reasonable in the diagnosis of EOS.

[Diagnostic value of procalcitonin in neonatal early-onset sepsis].

OBJECTIVE: To study the value of procalcitonin (PCT) within 3 days after birth in the diagnosis of neonatal early-onset sepsis (EOS), as well as the thresholds of PCT in the diagnosis of EOS in neonates with different gestational ages and different ages. METHODS: A total of 109 neonates with a confirmed diagnosis of sepsis, 215 neonates with clinically diagnosed sepsis, and 367 neonates without sepsis were enrolled. Receiver operating characteristic (ROC) curves were plotted to determine the optimal cut-off values of PCT in the diagnosis of EOS in neonates with different gestational ages and different ages. The diagnostic value of PCT and blood culture was compared. RESULTS: In the confirmed diagnosis group, the neonates with a gestational age of <34 weeks had a significantly higher level of PCT than those with a gestational age of ≥34 weeks (P<0.05). For the neonates with a gestational age of ≥34 weeks, the optimal cut-off values of PCT in the diagnosis of EOS were 1.588 ng/mL (sensitivity 0.688, specificity 0.851) at age of <12 hours, 4.960 ng/mL (sensitivity 0.737, specificity 0.883) at age of 12 - <24 hours, 5.583 ng/mL (sensitivity 0.727, specificity 0.865) at age of 24 - <36 hours, 1.710 ng/mL (sensitivity 0.732, specificity 0.755) at age of 36 - <48 hours, 3.570 ng/mL (sensitivity 0.488, specificity 0.930) at age of 48 -<60 hours, and 3.574 ng/mL (sensitivity 0.333, specificity 0.900) at age of 60 - 72 hours. PCT had a larger area under the ROC curve in the diagnosis of EOS than blood culture within 36 hours after birth (P<0.05). CONCLUSIONS: The same criteria can be used for late preterm infants (with a gestational age of ≥34 weeks) and full-term infants, while early preterm infants (with a gestational age of <34 weeks) should be considered separately. PCT has different optimal cut-off values in the diagnosis of EOS in neonates with different ages, with a higher value than blood culture in the diagnosis of EOS within 36 hours after birth.

Cucumber mosaic virus coat protein modulates the accumulation of 2b protein and antiviral silencing that causes symptom recovery in planta.

Shoot apical meristems (SAM) are resistant to most plant viruses due to RNA silencing, which is restrained by viral suppressors of RNA silencing (VSRs) to facilitate transient viral invasion of the SAM. In many cases chronic symptoms and long-term virus recovery occur, but the underlying mechanisms are poorly understood. Here, we found that wild-type Cucumber mosaic virus (CMVWT) invaded the SAM transiently, but was subsequently eliminated from the meristems. Unexpectedly, a CMV mutant, designated CMVRA that harbors an alanine substitution in the N-terminal arginine-rich region of the coat protein (CP) persistently invaded the SAM and resulted in visible reductions in apical dominance. Notably, the CMVWT virus elicited more potent antiviral silencing than CMVRA in newly emerging leaves of infected plants. However, both viruses caused severe symptoms with minimal antiviral silencing effects in the Arabidopsis mutants lacking host RNA-DEPENDENT RNA POLYMERASE 6 (RDR6) or SUPPRESSOR OF GENE SILENCING 3 (SGS3), indicating that CMVWT induced host RDR6/SGS3-dependent antiviral silencing. We also showed that reduced accumulation of the 2b protein is elicited in the CMVWT infection and consequently rescues potent antiviral RNA silencing. Indeed, co-infiltration assays showed that the suppression of posttranscriptional gene silencing mediated by 2b is more severely compromised by co-expression of CPWT than by CPRA. We further demonstrated that CPWT had high RNA binding activity leading to translation inhibition in wheat germ systems, and CPWT was associated with SGS3 into punctate granules in vivo. Thus, we propose that the RNAs bound and protected by CPWT possibly serve as templates of RDR6/SGS3 complexes for siRNA amplification. Together, these findings suggest that the CMV CP acts as a central hub that modulates antiviral silencing and VSRs activity, and mediates viral self-attenuation and long-term symptom recovery.

[Clinical value of blood lactate in predicting the prognosis of neonatal sepsis].

OBJECTIVE: To explore the clinical value of arterial blood lactate level in predicting the prognosis of neonatal sepsis. METHODS: The clinical data of 301 cases of neonatal sepsis were collected, which mainly included biochemical indicators such as blood lactate on admission, C-reactive protein, and procalcitonin. ROC curves were plotted to evaluate the value of lactate level on admission in predicting the prognosis of neonatal sepsis. RESULTS: The mortality rate was significantly higher for full-term infants in the severely-elevated lactate group than in the mildly-elevated lactate group and the normal lactate group (26.1% vs 3.1% and 0%; P<0.017). The poor prognosis group had a significantly increased lactate level on admission compared with the good prognosis group (6.5±5.1 mmol/L vs 3.6±1.7 mmol/L; P<0.05). The sensitivity and specificity of blood lactate level on admission (cutoff value: 6.15 mmol/L) were 0.545 and 0.919 respectively, in predicting the prognosis of neonatal sepsis. CONCLUSIONS: Early blood lactate level can be used as a biochemical parameter to predict the prognosis of neonatal sepsis as it has a high specificity but a low sensitivity.

Brassica yellows virus P0 protein impairs the antiviral activity of NbRAF2 in Nicotiana benthamiana.

In interactions between poleroviruses and their hosts, few cellular proteins have been identified that directly interact with the multifunctional virus P0 protein. To help explore the functions of P0, we identified a Brassica yellows virus genotype A (BrYV-A) P0BrA-interacting protein from Nicotiana benthamiana, Rubisco assembly factor 2 (NbRAF2), which localizes in the nucleus, cell periphery, chloroplasts, and stromules. We found that its C-terminal domain (amino acids 183-211) is required for self-interaction. A split ubiquitin membrane-bound yeast two-hybrid system and co-immunoprecipitation assays showed that NbRAF2 interacted with P0BrA, and co-localized in the nucleus and at the cell periphery. Interestingly, the nuclear pool of NbRAF2 decreased in the presence of P0BrA and during BrYV-A infection, and the P0BrA-mediated reduction of nuclear NbRAF2 required dual localization of NbRAF2 in the chloroplasts and nucleus. Tobacco rattle virus-based virus-induced gene silencing of NbRAF2 promoted BrYV-A infection in N. benthamiana, and the overexpression of nuclear NbRAF2 inhibited BrYV-A accumulation. Potato leafroll virus P0PL also interacted with NbRAF2 and decreased its nuclear accumulation, indicating that NbRAF2 may be a common target of poleroviruses. These results suggest that nuclear NbRAF2 possesses antiviral activity against BrYV-A infection, and that BrYV-A P0BrA interacts with NbRAF2 and alters its localization pattern to facilitate virus infection.

Prenatal and postnatal antibiotic exposure influences the gut microbiota of preterm infants in neonatal intensive care units.

BACKGROUND: To explore the influences of prenatal antibiotic exposure, the intensity of prenatal and postnatal antibiotic exposure on gut microbiota of preterm infants and whether gut microbiota and drug resistant strains in the neonatal intensive care unit (NICU) over a defined period are related. METHODS: Among 28 preterm infants, there were two groups, the PAT (prenatal antibiotic therapy) group (12 cases), and the PAF (prenatal antibiotic free) group (12 cases). Fecal samples from both groups were collected on days 7 and 14. According to the time of prenatal and postnatal antibiotic exposure, cases were divided into two groups, H (high) group (11 cases) and L (low) group (11 cases), and fecal samples on day 14 were collected. Genomic DNA was extracted from the fecal samples and was subjected to high throughput 16S rRNA amplicon sequencing. Bioinformatics methods were used to analyze the sequencing results. RESULTS: Prenatal and postnatal antibiotic exposure exercised influence on the early establishment of intestinal microflora of preterm infants. Bacteroidetes decreased significantly in the PAT group (p < 0.05). The number of Bifidobacterium significantly decreased in the PAT group and H group (p < 0.05). The early gut microbiota of preterm infants with prenatal and postnatal antibiotic exposure was similar to resistant bacteria in NICU during the same period. CONCLUSION: Prenatal and postnatal antibiotic exposure may affect the composition of early gut microbiota in preterm infants. Antibiotic-resistant bacteria in NICU may play a role in reshaping the early gut microbiota of preterm infants with prenatal and postnatal antibiotic exposure.

Identification and Characterization of a New 7-Aminocephalosporanic Acid Deacetylase from Thermophilic Bacterium Alicyclobacillus tengchongensis.

UNLABELLED: Deacetylation of 7-aminocephalosporanic acid (7-ACA) at position C-3 provides valuable starting material for producing semisynthetic ß-lactam antibiotics. However, few enzymes have been characterized in this process before now. Comparative analysis of the genome of the thermophilic bacterium Alicyclobacillus tengchongensis revealed a hypothetical protein (EstD1) with typical esterase features. The EstD1 protein was functionally cloned, expressed, and purified from Escherichia coli BL21(DE3). It indeed displayed esterase activity, with optimal activity at around 65°C and pH 8.5, with a preference for esters with short-chain acyl esters (C2 to C4). Sequence alignment revealed that EstD1 is an SGNH hydrolase with the putative catalytic triad Ser15, Asp191, and His194, which belongs to carbohydrate esterase family 12. EstD1 can hydrolyze acetate at the C-3 position of 7-aminocephalosporanic acid (7-ACA) to form deacetyl-7-ACA, which is an important starting material for producing semisynthetic ß-lactam antibiotics. EstD1 retained more than 50% of its initial activity when incubated at pH values ranging from 4 to 11 at 65°C for 1 h. To the best of our knowledge, this enzyme is a new SGNH hydrolase identified from thermophiles that is able to hydrolyze 7-ACA. IMPORTANCE: Deacetyl cephalosporins are highly valuable building blocks for the industrial production of various kinds of semisynthetic ß-lactam antibiotics. These compounds are derived mainly from 7-ACA, which is obtained by chemical or enzymatic processes from cephalosporin C. Enzymatic transformation of 7-ACA is the main method because of the adverse effects chemical deacylation brought to the environment. SGNH hydrolases are widely distributed in plants. However, the tools for identifying and characterizing SGNH hydrolases from bacteria, especially from thermophiles, are rather limited. Here, our work demonstrates that EstD1 belongs to the SGNH family and can hydrolyze acetate at the C-3 position of 7-ACA. Moreover, this study can enrich our understanding of the functions of these enzymes from this family.

Zinc as an adjunct to antibiotics for the treatment of severe pneumonia in children <5 years: a meta-analysis of randomised-controlled trials.

The effect of Zn, as an adjunct to antibiotics, on the treatment of severe pneumonia in young children is still under debate; therefore, we performed a meta-analysis to evaluate the therapeutic role of Zn for severe pneumonia in children younger than 5 years. PubMed, Cochrane library and Embase databases were systematically searched from inception until October 2015 for randomised-controlled trials (RCT) that assessed the effect of Zn as an adjunct to antibiotics for severe pneumonia. Random-effects model was used for calculating the pooled estimates, and intention-to-treat principle was also applied. Nine RCT involving 2926 children were included. Overall, the pooled results showed that adjunct treatment with Zn failed to reduce the time to recovery from severe pneumonia (hazard ratios (HR)=1·04; 95% CI 0·90, 1·19; I(2)=39%; P=0·58), hospital length of stay (HR=1·04; 95% CI 0·83, 1·33; I(2)=57%; P=0·74), treatment failure (relative risk (RR)=0·95; 95% CI 0·79, 1·14; I(2)=20%; P=0·58) or change of antibiotics (RR=1·07; 95% CI 0·79, 1·45; I(2)=44%; P=0·67). In addition, continuous outcomes were consistent while meta-analysed with standard mean difference, and all outcomes remained stable in intention-to-treat analysis. No significant differences were observed in the two groups between death rate, adverse events or recovery times of severe pneumonia indicators. Our results suggested that adjunct treatment with Zn failed to benefit young children in the treatment of severe pneumonia. Considering the clinical heterogeneity, baseline characteristics of children, definition of severe pneumonia and Zn supplement way should be taken into consideration in future research. This study was registered at PRESPERO as CRD42015019798.

Dissipation of excess excitation energy of the needle leaves in Pinus trees during cold winters.

Photooxidative damage to the needle leaves of evergreen trees results from the absorption of excess excitation energy. Efficient dissipation of this energy is essential to prevent photodamage. In this study, we determined the fluorescence transients, absorption spectra, chlorophyll contents, chlorophyll a/b ratios, and relative membrane permeabilities of needle leaves of Pinus koraiensis, Pinus tabulaeformis, and Pinus armandi in both cold winter and summer. We observed a dramatic decrease in the maximum fluorescence (F m) and substantial absorption of light energy in winter leaves of all three species. The F m decline was not correlated with a decrease in light absorption or with changes in chlorophyll content and chlorophyll a/b ratio. The results suggested that the winter leaves dissipated a large amount of excess energy as heat. Because the cold winter leaves had lost normal physiological function, the heat dissipation depended solely on changes in the photosystem II supercomplex rather than the xanthophyll cycle. These findings imply that more attention should be paid to heat dissipation via changes in the photosystem complex structure during the growing season.

Amino acid sequence motifs essential for P0-mediated suppression of RNA silencing in an isolate of potato leafroll virus from Inner Mongolia.

Polerovirus P0 suppressors of host gene silencing contain a consensus F-box-like motif with Leu/Pro (L/P) requirements for suppressor activity. The Inner Mongolian Potato leafroll virus (PLRV) P0 protein (P0(PL-IM)) has an unusual F-box-like motif that contains a Trp/Gly (W/G) sequence and an additional GW/WG-like motif (G139/W140/G141) that is lacking in other P0 proteins. We used Agrobacterium infiltration-mediated RNA silencing assays to establish that P0(PL-IM) has a strong suppressor activity. Mutagenesis experiments demonstrated that the P0(PL-IM) F-box-like motif encompasses amino acids 76-LPRHLHYECLEWGLLCG THP-95, and that the suppressor activity is abolished by L76A, W87A, or G88A substitution. The suppressor activity is also weakened substantially by mutations within the G139/W140/G141 region and is eliminated by a mutation (F220R) in a C-terminal conserved sequence of P0(PL-IM). As has been observed with other P0 proteins, P0(PL-IM) suppression is correlated with reduced accumulation of the host AGO1-silencing complex protein. However, P0(PL-IM) fails to bind SKP1, which functions in a proteasome pathway that may be involved in AGO1 degradation. These results suggest that P0(PL-IM) may suppress RNA silencing by using an alternative pathway to target AGO1 for degradation. Our results help improve our understanding of the molecular mechanisms involved in PLRV infection.

Infection of Beet necrotic yellow vein virus with RNA4-encoded P31 specifically up-regulates pathogenesis-related protein 10 in Nicotiana benthamiana.

BACKGROUND: Beet necrotic yellow vein virus (BNYVV) is the infectious agent of sugar beet rhizomania, which consists of four or five plus-sense RNAs. RNA4 of BNYVV is not essential for virus propagation in Nicotiana benthamiana but has a major effect on symptom expression. Early reports showed that RNA4-encoded P31 was associated with severe symptoms, such as curling and dwarfing, in N. benthamiana. RESULTS: We discovered that the pathogenesis-related protein 10 (PR-10) gene can be up-regulated in BNYVV-infected N. benthamiana in the presence of RNA4 and that it had a close link with symptom development. Our frame-shift, deletion and substitution analysis showed that only the entire P31 could induce PR-10 up-regulation during BNYVV infection and that all the tryptophans and six cysteines (C174, C183, C186, C190, C197 and C199) in the cysteine-rich P31 had significant effects on PR-10 expression. However, P31 could not interact directly with PR-10 in yeast. CONCLUSIONS: Our data demonstrated that only integrated P31 specifically induced PR-10 transcription, which coincided closely with the appearance of severe symptoms in BNYVV-infected N. benthamiana, although they could not interact directly with each other in yeast.

Complete genome sequence analysis identifies a new genotype of brassica yellows virus that infects cabbage and radish in China.

For brassica yellows virus (BrYV), proposed to be a member of a new polerovirus species, two clearly distinct genotypes (BrYV-A and BrYV-B) have been described. In this study, the complete nucleotide sequences of two BrYV isolates from radish and Chinese cabbage were determined. Sequence analysis suggested that these isolates represent a new genotype, referred to here as BrYV-C. The full-length sequences of the two BrYV-C isolates shared 93.4-94.8 % identity with BrYV-A and BrYV-B. Further phylogenetic analysis showed that the BrYV-C isolates formed a subgroup that was distinct from the BrYV-A and BrYV-B isolates based on all of the proteins except P5.

[Changes on the expression of aquaporin-4 is associated with edema of brain in neonatal rats subjected to hypoxic ischemic brain damage].

OBJECTIVE: To investigate changes of Aquaporin-4 (AQP-4) and the relation of brain edema after different time of hypoxic ischemic brain damage (HIBD). METHODS: Healthy 3 day-old SD rats (n=60), were divided into Sham group (n=12), the hypoxic ischemic brain damage group (n=48). The rats were subjected to the ligation of right carotid artery (ischemia). After rewarming 30 min with mother, they were sent into a box full with 80 mL/L oxygen and 920 mL/L nitrogen (hypoxia) for 4 h, 8 h, 16 h, 24 h (n=12 respectively). The rats of sham group were subjected to exposure right carotid artery, but were not ligated. Rats of the HIBD group were sacrificed at 4 h, 8 h, 16 h, 24 h of hypoxic ischemic damage and rats of the sham group were sacrificed at 12 h after operation without hypoxic ischemic damage. Then brain water content from left and right hemisphere were investigated respetively to observe brain edema at different time of hypoxic ischemic brain damage, which was followed by the investigation of brain pathology through HE staining. Real time PCR was used to test the level of AQP-4 mRNA. RESULTS: Water content of right brain increased significantly after 8 h, 16 h and 24 h hypoxic ischemic brain damage, compared with the sham group (P < 0.05). Under light microscopy, the size of neurons and glia cells increased gradually during 8-24 h following HIBD. Dissolved Neurons were obviously observed during 16-24 h of HIBD. Glia cells were scarcely distributed. The mRNA expression of AQP-4 in right hippocampus decreased significantly during 4-24h of HIBD by evaluated with real time PCR (P < 0.05), when compared with the sham group. CONCLUSION: AQP-4 mRNA expression in hippocampus of neonatal rats with HIBD exhibited a significant decrease, which was associated with brain edema. The present findings indicated that AQP-4 may has a novel role in the brain edema in neonatal rats with HIBD.

Pharmacokinetics and safety evaluation of intravenously administered Pseudomonas phage PA_LZ7 in a mouse model.

IMPORTANCE: Phage therapy is gaining traction as an alternative to antibiotics due to the rise of multi-drug-resistant (MDR) bacteria. This study assessed the pharmacokinetics and safety of PA_LZ7, a phage targeting MDR Pseudomonas aeruginosa, in mice. After intravenous administration, the phage showed an exponential decay in plasma and its concentration dropped significantly within 24 h for all dosage groups. Although there was a temporary increase in certain plasma cytokines and spleen weight at higher dosages, no significant toxicity was observed. Therefore, PA_LZ7 shows potential as an effective and safe candidate for future phage therapy against MDR P. aeruginosa infections.

Does congenital cytomegalovirus infection lead to hearing loss by inducing mutation of the GJB2 gene?

BACKGROUND: Congenital cytomegalovirus (CMV) infection and mutation of the gap junction ß-2 (GJB2) gene are important causes of sensorineural hearing loss (SNHL). This study aims to determine if congenital CMV infection leads to deafness by inducing GJB2 mutation. METHODS: GJB2 gene sequencing and auditory brainstem response testing were performed in 159 neonates (63 with and 96 without CMV infection) from August 2008 to August 2011. For neonates with GJB2 mutation, their parents were further screened for GJB2 sequence. RESULTS: The incidence of SNHL was 12.7% in CMV-infected but 0% in uninfected children aged 1-1.5 y (P = 0.000). Similar mutation rates of the GJB2 gene were observed in neonates with or without CMV infection (34.9 vs. 32.3%, respectively, P = 0.734). No significant difference in the mutation rate of GJB2 was found among neonates with CMV infection and SNHL, those with CMV infection and normal hearing, and uninfected newborns with normal hearing (P = 0.438). Mutations 79G>A, 109G>A, 341A>G, and 608T>C were found in neonates with and without CMV infection. All of the above mutations were also found in both or one of the corresponding parents. CONCLUSION: Congenital CMV infections may cause deafness in neonates, but this might be independent of GJB2 gene mutation.