Microplastic fibers influence Ag toxicity and bioaccumulation in Eisenia andrei but not in Enchytraeus crypticus

Microplastic fibers (MF) are released from synthetic textiles during washing and end up in the wastewater. Similarly, silver nanoparticles (AgNP), incorporated in textiles as antimicrobial agents, are released in washing machines, also reaching the wastewater treatment plants. Therefore, both MF and AgNP co-exist in the environment, and enter the soil compartment mainly via the application of biosolids. Yet, the combined effect of MF and AgNP has not been studied. Here, we assessed the effects of polyester MF (0.01% DW) on the toxicity of AgNP (32, 100, 320, 1000, 3200 mg Ag/kg) and AgNO3 (12.8, 32, 80, 200, 500 mg Ag/kg) to the earthworm Eisenia andrei and the enchytraeid Enchytraeus crypticus. The exposure to MF caused a decrease in the number of juveniles and changed the biochemical composition of earthworms. Moreover, the presence of MF increased the toxicity of AgNP to earthworm reproduction (EC50 = 165 mg Ag/kg) when compared to AgNP exposure alone (EC50 = 450 mg Ag/kg), but did not alter the toxicity of AgNO3 (EC50 = 40 mg Ag/kg). For enchytraeids, no significant difference in Ag toxicity could be detected when MF was added to the soil for both AgNP and AgNO3. Overall, Ag bioaccumulation was not affected by MF, with the exception of a decrease in earthworm body concentration at the highest Ag soil concentration (3200 mg Ag/kg). Our results suggest that the presence of MF in the soil compartment may be a cause of concern, and that the joint exposure to Ag may be deleterious depending on the Ag form, organism and endpoint. The present work provides the first evidence that a realistic MF concentration in soil lowers AgNP concentration necessary to provoke reproductive impairment in earthworms. The influence of MF on risk assessment of AgNP should be considered.

Characterization of alphabaculovirus: HearNPV-IIPR05 isolate infecting Helicoverpa armigera (Hubner) larvae

Background The alphabaculoviruses are lethal pathogens of lepidopteran caterpillars including a polyphagous and globally recognized pest, Helicoverpa armigera (Hubner) infesting economically important agriculture crops worldwide. The biological and molecular characterizations of indigenous nucleopolyhedrovirus of the genus Alphabaculovirus isolated from H. armigera in chickpea fields are described. Results The virulence of virus isolate was tested in 3rd instar H. armigera larvae, and LC50 (median lethal concentration) was estimated to be 2.69 × 104 OBs ml−1. The ST50 (median survival time) was 4 days post-inoculation, when the 3rd instar H. armigera larvae were inoculated by OB (occlusion body) concentration equivalent to LC90. An average incubation period of the virus isolate in 3rd instar ranged between 4 and 6 days post-inoculation. The OBs of a virus isolate appeared irregular in shape and variable in size with diameter ranging from 0.57 to 1.46 μm on the longest edge and average of 1.071 ± 0.068 μm (mean ± SE). On the basis of phylogenetic analysis of polh, pif-1, and lef-8 genes, the isolate was found to be a member of the genus Alphabaculovirus. The isolate showed a genetic affinity with species of group II Alphabaculoviruses and appeared to be a group II NPV. Conclusions On the basis of molecular phylogeny and associated host insect, this indigenous isolate was designated as HearNPV-IIPR05 isolate, which could be a potential candidate for the biological control of H. armigera infesting legumes and other commercial crops.

A quantitative inventory of yeast P body proteins reveals principles of composition and specificity

P bodies are archetypal biomolecular condensates that concentrate proteins and RNA without a surrounding membrane. While dozens of P body proteins are known, the concentrations of components in the compartment have not been measured. We used live cell imaging to generate a quantitative inventory of the major proteins in yeast P bodies. Only seven proteins are highly concentrated in P bodies (5.1–15µM); the 24 others examined are appreciably lower (most ≤ 2.6µM). P body concentration correlates inversely with cytoplasmic exchange rate. Sequence elements driving Dcp2 concentration into P bodies are distributed across the protein and act synergistically. Our data indicate that P bodies, and probably other condensates, are compositionally simpler than suggested by proteomic analyses, with implications for specificity, reconstitution and evolution.

A quantitative inventory of yeast P body proteins reveals principles of composition and specificity

ABSTRACTP bodies are archetypal biomolecular condensates that concentrate proteins and RNA without a surrounding membrane. While dozens of P body proteins are known, the concentrations of components in the compartment have not been measured. We used live cell imaging to generate a quantitative inventory of the major proteins in yeast P bodies. Only 7 proteins are highly concentrated in P bodies (5.1-15 uM); the 24 others examined are appreciably lower (most ≤ 2.6 uM). P body concentration correlates inversely with cytoplasmic exchange rate. Sequence elements driving Dcp2 concentration into P bodies are distributed across the protein and act cooperatively. Our data indicate that P bodies, and probably other condensates, are biochemically simpler than suggested by proteomic analyses, with implications for specificity, reconstitution and evolution.

The prevalence of hyaline membrane disease and the value of shake test and lamellar body concentration in preterm infants

Background The morbidity and mortality of hyaline membrane dis-ease (HMD) are quite high due to delayed diagnosis and intervention.Commonly, HMD occurs in preterm infants with surfactant deficiencybecause of lung immaturity. Lung maturity test could be performedusing biochemical, biophysical, and amniotic fluid turbidity test.Objective To find out HMD prevalence and the value of shaketest and lamellar body concentration in diagnosing HMD in preterminfants.Methods This was a cross-sectional study carried out at HasanSadikin Hospital Bandung on preterm infants born during October-December 2001. The shake test was performed using gastric fluidand amniotic fluid while the lamellar body concentration was per-formed using amniotic fluid.Results During the 3-month period, 571 infants were born, of 64(11.2%) preterm infants, only 41 (64%) fulfilled the inclusion crite-ria; among those preterm infants, 14 (34%) suffered from respira-tory distress and 7 suffered from HMD (prevalence 17%). All HMDcases occurred in infants less than 32 weeks for gestational age.In 7 preterm infants with HMD, the shake test of gastric fluid ob-tained by lavage showed negative results in 3 and +1 in 4 infants;while the shake test of amniotic fluid revealed negative result in 5and +1 in 2 infants. Lamellar body concentration of amniotic fluidwas ≤18,000/ml in all HMD infants. Among three infants less than32 weeks for gestational age who did not suffer from HMD, +1shake test of gastric fluid was found in 2 infants and +2 in 1 infant;while shake test of amniotic fluid showed negative result in 1 infantand +1 in 2; the lamellar body concentration of amniotic fluid was≤18,000/ml in 2 infants and >18,000/ml in 1 infant.Conclusions We concluded that HMD occurred in 17% of preterminfants. The shake test of gastric and amniotic fluids revealed nega-tive or +1 results whereas lamellar body concentration had valueof less than or equal to 18,000/mL. More extensive studies arewarranted to assess the validity (sensitivity, specificity and predic-tive values) of these measurements