Preliminary results on nematicidal activity from culture filtrates of Basidiomycetes against the pine wood nematode,Bursaphelenchus xylophilus (Aphelenchoididae)

One hundred and eighty one fungal species that were isolated from the fresh fruiting bodies collected in the Mountains of Pu Er County of Yunnan Province, China were tested on the pine wood nematode,Bursaphelenchus xylophilus in vitro. Each fungal species was grown in Czapek broth and potato dextrose broth (PDB). Fifteen filtrates fromAmauroderma austrosinense, Amauroderma macer, Filoboletus sp.,Laccaria tortilis, Lactarius gerardii, Lentinula edodes, Oudemansiella longipes, Oudemansiella mucida, Peziza sp.,Pleurotus sp.,Sinotermitomyces carnosus (two strains),Strobilomyces floccopus, Termitomyces albuminosus, Tylopilus striatulus grown on PDB were found to be pathogenic to the tested nematodes. Eleven filtrates fromAmanita junguillea, Amanita sp.,Daedalea sepiaria, Fistulina hepatica, Omphalotus olearius, Oudemansiella mucida, Peziza sp.,Pleurotus pulmatus, Ramaria sp.,Tricholoma conglobatum, Tylopilus striatulus grown on Czapek broth were also pathogenic to the nematodes. When screening for nematicidal potential of fungi, it is important to study the growth medium conditions necessary to obtain the optimal nematicidal effect as fungal filtrates growing on different liquid media showed a very inconsistent toxicity towards nematodes.     

Influenza A virus-binding activity of glycoglycerolipids of aquatic bacteria

As the aqueous sphere has been proposed to be an important source medium for the virus infection of land animals, the glycolipids of some aquatic organisms were examined for human influenza A virus-binding activity. Active compounds were not found among the eight echinoderm gangliosides, but two active non-sialylated glycoglycerolipids were isolated from an aquatic bacterium, Corynebacterium aquaticum. The structural formula of one of them, H632A, was elucidated to be 1-14-methyl-hexadecanoyl-3-alpha-D-galactopyranosyl-(1-->3)-6-(12-met hyl-tetradecanoyl)-1-alpha-D-mannopyranosyl]-sn-glycerol. The latter together with reported one elsewhere, S365A, 1-14-methyl-hexadecanoyl-3-[alpha-D-mannopyranosyl-(1-->3)-6-(12-meth yl-tetradecanoyl)-1-alpha-D-mannopyranosyl]-sn-glycerol, apparently bound to three human influenza viruses, A/PR/8/34 (H1N1), A/Aichi/2/68 (H3N2), and A/Memphis/1/71 (H3N2), exhibiting 7-12% (H632A) and 10-22% (S365A) of the activities of the control substances (Neu5Acalpha2-3-paragloboside and Neu5Acalpha2-6- paragloboside). Additionally, these glycolipids were assumed to have virus-neutralizing activities for the following two reasons: (i) The hemagglutination and hemolysis activities of the viruses were inhibited by the glycolipid. (ii) The leakage of a cytosolic enzyme (lactate dehydrogenase) from Madin-Darby canine kidney cells on virus infection was prevented by the glycolipids to nearly the same extent as by fetuin. This is the first evidence of the binding- and neutralizing-abilities of native glycoglycerolipids as to influenza viruses.     

Dexamethasone interferes with osteoblasts formation during osteogenesis through altering IGF-1-mediated angiogenesis

Dexamethasone (Dex), a synthetic glucocorticoid (GC) with long-lasting treatment effects, has been proved to exert a modulatory effect on osteoblast proliferation and differentiation during embryonic osteogenesis. However, it is still controversial if Dex exposure influences endochondral ossification and the underlying mechanism. In this study, chick embryos in vivo and preosteoblast cell cultures in vitro were utilized to investigate the effects of Dex on osteoblast formation and differentiation during the skeletal development. We first demonstrated that Dex exposure could shorten the long bones of 17-day chick embryos in vivo, and also downregulated the expressions of osteogenesis-related genes. Next, we established that Dex exposure inhibited the proliferation and viability of preosteoblasts-MC3TC-E1 cells, and the addition of insulin-like growth factor 1 (IGF-1) could dramatically rescue these negative effects. On the basis of remarkable changes in the rescue experiments, we next verified the important role of angiogenesis in osteogenesis by culturing isolated embryonic phalanges in Dulbecco's modified Eagle's medium culture or on the chick chorioallantoic membrane (CAM). Then, we transplanted MC3T3-E1 cell masses onto the CAM. The data showed that Dex exposure reduced the vessel density within the developed cell mass, concomitantly with the downregulation of IGF-1 pathway. We verified that the inhibition of blood vessel formation caused by Dex could be rescued by IGF-1 treatment using the CAM angiogenesis model. Eventually, we demonstrated that the shortened length of the phalanges in the presence of Dex could be reversed by IGF-1 addition. In summary, these findings suggested that the inhibition of Igf-1 signal caused by Dex exposure exerts a detrimental impact on the formation of osteoblasts and angiogenesis, which consequently shortens long bones during osteogenesis.     

Disparities in distribution of COVID-19 vaccines across US counties: A geographic information system–based cross-sectional study

BackgroundThe US Centers for Disease Control and Prevention has repeatedly called for Coronavirus Disease 2019 (COVID-19) vaccine equity. The objective our study was to measure equity in the early distribution of COVID-19 vaccines to healthcare facilities across the US. Specifically, we tested whether the likelihood of a healthcare facility administering COVID-19 vaccines in May 2021 differed by county-level racial composition and degree of urbanicity.Methods and findingsThe outcome was whether an eligible vaccination facility actually administered COVID-19 vaccines as of May 2021, and was defined by spatially matching locations of eligible and actual COVID-19 vaccine administration locations. The outcome was regressed against county-level measures for racial/ethnic composition, urbanicity, income, social vulnerability index, COVID-19 mortality, 2020 election results, and availability of nontraditional vaccination locations using generalized estimating equations.Across the US, 61.4% of eligible healthcare facilities and 76.0% of eligible pharmacies provided COVID-19 vaccinations as of May 2021. Facilities in counties with >42.2% non-Hispanic Black population (i.e., > 95th county percentile of Black race composition) were less likely to serve as COVID-19 vaccine administration locations compared to facilities in counties with <12.5% non-Hispanic Black population (i.e., lower than US average), with OR 0.83; 95% CI, 0.70 to 0.98, p = 0.030. Location of a facility in a rural county (OR 0.82; 95% CI, 0.75 to 0.90, p < 0.001, versus metropolitan county) or in a county in the top quintile of COVID-19 mortality (OR 0.83; 95% CI, 0.75 to 0.93, p = 0.001, versus bottom 4 quintiles) was associated with decreased odds of serving as a COVID-19 vaccine administration location.There was a significant interaction of urbanicity and racial/ethnic composition: In metropolitan counties, facilities in counties with >42.2% non-Hispanic Black population (i.e., >95th county percentile of Black race composition) had 32% (95% CI 14% to 47%, p = 0.001) lower odds of serving as COVID administration facility compared to facilities in counties with below US average Black population. This association between Black composition and odds of a facility serving as vaccine administration facility was not observed in rural or suburban counties. In rural counties, facilities in counties with above US average Hispanic population had 26% (95% CI 11% to 38%, p = 0.002) lower odds of serving as vaccine administration facility compared to facilities in counties with below US average Hispanic population. This association between Hispanic ethnicity and odds of a facility serving as vaccine administration facility was not observed in metropolitan or suburban counties.Our analyses did not include nontraditional vaccination sites and are based on data as of May 2021, thus they represent the early distribution of COVID-19 vaccines. Our results based on this cross-sectional analysis may not be generalizable to later phases of the COVID-19 vaccine distribution process.ConclusionsHealthcare facilities in counties with higher Black composition, in rural areas, and in hardest-hit communities were less likely to serve as COVID-19 vaccine administration locations in May 2021. The lower uptake of COVID-19 vaccinations among minority populations and rural areas has been attributed to vaccine hesitancy; however, decreased access to vaccination sites may be an additional overlooked barrier.

Inmaculada Hernandez and colleagues investigate the disparities in early-phase distribution of COVID-19 Vaccines across U.S. Counties.     

水稻大粒种质资源和遗传分析

谷粒重量是构成产量的三要素之一, 对提高水稻产量具有重要意义。本文概述了国内外水稻大粒种质资源的现状, 同时对粒重基因遗传分析的研究进展进行了综述。粒重是一个受多基因控制的数量性状, 目前定位的粒重数量性状位点至少达89个、精细定位1个粒重基因gw3.1和１个长粒基因Lk-4(t)以及克隆1个粒重基因GS3, 并在此基础上讨论了粒重在育种上的应用。     

Sensory cues for the gradual frequency fall responses of the gymnotiform electric fish, Rhamphichthys rostratus

The sensory cues for a less known form of frequency shifting behavior, gradual frequency falls, of electric organ discharges (EODs) in a pulse-type gymnotiform electric fish, Rhamphichthys rostratus, were identified. We found that the gradual frequency fall occurs independently of more commonly observed momentary phase shifting behavior, and is due to perturbation of sensory feedback of the fish's own EODs by EODs of neighboring fish. The following components were identified as essential features in the signal mixture of the fish's own and the neighbor's EOD pulses: (1) the neighbor's pulses must be placed within a few millisecond of the fish's own pulses, (2) the neighbor's pulses, presented singly at low frequencies (0.2–4 Hz), were sufficient, (3) the frequency of individual pulse presentation must be below 4 Hz, (4) amplitude modulation of the sensory feedback of the fish's own pulses induced by such insertions of the neighbor's pulses must contain a high frequency component: sinusoidal amplitude modulation of the fish's own EOD feedback at these low frequencies does not induce gradual frequency falls. Differential stimulation across body surfaces, which is required for the jamming avoidance response (JAR) of wave-type gymnotiform electric fish, was not necessary for this behavior. We propose a cascade of high-pass and low-pass frequency filters within the amplitude processing pathway in the central nervous system as the mechanism of the gradual frequency fall response.Abbreviations EOD electric organ discharge - f frequency of EOD or pacemaker command signal - JAR jamming avoidance response - S ₁ stimulus mimicking fish's own EOD - f ₁ frequency of S₁ - S ₂ stimulus mimicking neighbor's EOD - f ₂ frequency of S₂     

Characterization of fibroblasts recruited from bone marrow-derived precursor in neonatal bronchopulmonary dysplasia mice

We sought to determine whether the extrapulmonary origin of fibroblasts derived from bone marrow (BM) progenitor cells is essential to lung fibrosis in bronchopulmonary dysplasia (BPD). Neonate mice were durably engrafted with BM isolated from transgenic reporter mice that expressed green fluorescent protein (GFP). Such chimera mice were subjected to 60% O(2) exposure for 14 days. A large number of fibroblast-specific protein-1 (FSP1) and GFP-positive fibroblasts were identified in active fibrotic lesions. More surprisingly, however, FSP1(+) fibroblasts also arose in considerable numbers from BM-derived alveolar type II cells (AT2) through epithelial-mesenchymal transition (EMT) during lung fibrogenesis. Cultured lung fibroblasts could express the CXC chemokine receptor (CXCR4) and responded chemotactically to their cognate ligand, chemokine (C-X-C motif) ligand 12 (CXCL12), which were elevated in the serum of BPD mice. These data suggest that lung fibroblasts in BPD fibrosis could variably arise from BM progenitor cells. This finding, which suggests the pathophysiological process of fibrosis, could contribute to a therapy for BPD that is characterized by extensive interstitial fibrosis.     

EP300 contributes to high-altitude adaptation in Tibetans by regulating nitric oxide production

The genetic adaptation of Tibetans to high altitude hypoxia likely involves a group of genes in the hypoxic pathway,as suggested by earlier studies.To test the adaptive role of the previously reported candidate gene EP300 (histone acetyltransferase p300),we conducted resequencing of a 108.9 kb gene region of EP300 in 80 unrelated Tibetans.The allele-frequency and haplotype-based neutrality tests detected signals of positive Darwinian selection on EP300 in Tibetans,with a group of variants showing allelic divergence between Tibetans and lowland reference populations,including Han Chinese,Europeans,and Africans.Functional prediction suggested the involvement of multiple EP300 variants in gene expression regulation.More importantly,genetic association tests in 226 Tibetans indicated significant correlation of the adaptive EP300 variants with blood nitric oxide (NO) concentration.Collectively,we propose that EP300 harbors adaptive variants in Tibetans,which might contribute to high-altitude adaptation through regulating NO production.