A Novel Fluorescent Labeling Method Enables Monitoring of Spatio‐Temporal Dynamics of Developing Microsporidia

The microsporidium, Anncaliia algerae (Brachiola algerae), is a eukaryotic obligate intracellular parasite first isolated from mosquitoes and is an important opportunistic human pathogen that can cause morbidity and mortality among immune‐compromised individuals including patients with AIDS and those undergoing chemotherapy. There is little known about the Microsporidia–host cell interface in living host cells, due to current approaches being limited by the lack of fluorescent reporters for detecting the parasite lifecycle. Here, we have developed and applied novel vital fluorescent parasite labeling methodologies in conjunction with fluorescent protein‐tagged reporters to track simultaneously the dynamics of both parasite and host cell specific components, including the secretory and endocytic trafficking pathways, during the entire infection time period. We have found dramatic changes in the dynamics of host secretory trafficking organelles during the course of infection. The Golgi compartment is gradually disassembled and regenerated into mini‐Golgi structures in parallel with cellular microtubule depolymerization. Importantly, we find that Microsporidia progeny are associated with these de novo formed mini‐Golgi structures. These host structures appear to create a membrane bound niche environment for parasite development. Our studies presented here provide novel imaging tools and methodologies that will facilitate in understanding the biology of microsporidial parasites in the living host.     

PROGRESS STUDY: Progression of chronic kidney disease in children and heat shock proteins

Various molecular and cellular processes are involved in renal fibrosis, such as oxidative stress, inflammation, endothelial cell injury, and apoptosis. Heat shock proteins (HSPs) are implicated in the progression of chronic kidney disease (CKD). Our aim was to evaluate changes in urine and serum HSP levels over time and their relationships with the clinical parameters of CKD in children. In total, 117 children with CKD and 56 healthy children were examined. The CKD group was followed up prospectively for 24 months. Serum and urine HSP27, HSP40, HSP47, HSP60, HSP70, HSP72, and HSP90 levels and serum anti-HSP60 and anti-HSP70 levels were measured by ELISA at baseline, 12 months, and 24 months. The urine levels of all HSPs and the serum levels of HSP40, HSP47, HSP60, HSP70, anti-HSP60, and anti-HSP70 were higher at baseline in the CKD group than in the control group. Over the months, serum HSP47 and HSP60 levels steadily decreased, whereas HSP90 and anti-HSP60 levels steadily increased. Urine HSP levels were elevated in children with CKD; however, with the exception of HSP90, they decreased over time. In conclusion, our study demonstrates that CKD progression is a complicated process that involves HSPs, but they do not predict CKD progression. The protective role of HSPs against CKD may weaken over time, and HSP90 may have a detrimental effect on the disease course.Supplementary InformationThe online version contains supplementary material available at 10.1007/s12192-021-01239-9.     

Arbuscular Mycorrhizal Symbiosis with Arundo donax Decreases Root Respiration and Increases Both Photosynthesis and Plant Biomass Accumulation

The effect of arbuscular mycorrhiza (AM) symbiosis on plant growth is associated with the balance between costs and benefits. A feedback regulation loop has been described in which the higher carbohydrate cost to plants for AM symbiosis is compensated by increases in their photosynthetic rates. Nevertheless, plant carbon balance depends both on photosynthetic carbon uptake and respiratory carbon consumption. The hypothesis behind this research was that the role of respiration in plant growth under AM symbiosis may be as important as that of photosynthesis. This hypothesis was tested in Arundo donax L. plantlets inoculated with Rhizophagus irregularis and Funneliformis mosseae. We tested the effects of AM inoculation on both photosynthetic capacity and in vivo leaf and root respiration. Additionally, analyses of the primary metabolism and ion content were performed in both leaves and roots. AM inoculation increased photosynthesis through increased CO₂ diffusion and electron transport in the chloroplast. Moreover, respiration decreased only in AM roots via the cytochrome oxidase pathway (COP) as measured by the oxygen isotope technique. This decline in the COP can be related to the reduced respiratory metabolism and substrates (sugars and tricarboxylic acid cycle intermediates) observed in roots.     

Preformulation Studies of a Prodrug of Δ9-Tetrahydrocannabinol

Preformulation studies were performed on a hemiglutarate ester prodrug of Δ⁹-tetrahydrocannabinol (THC-HG), to facilitate the development of stable formulations by hot-melt methods. The various studies performed included solid-state thermal characterization, pKa, logP, aqueous and pH dependent solubility, pH stability and effect of moisture, temperature and oxygen on solid-state stability. A hot-melt method was utilized to fabricate THC-HG incorporated poly (ethylene oxide) (PEO) matrices and the bioadhesive properties, release profiles and post-processing stability of these matrices were assessed as a function of the polymer molecular weight. The prodrug exhibited a T _g close to 0°C, indicating its amorphous nature. Thermogravimetric analysis revealed a rapid weight loss after 170°C. The prodrug exhibited a seven-fold higher aqueous solubility as compared to the parent drug (THC). Also, the solubility of the compound increased with increasing pH, being maximum at pH 8. The prodrug exhibited a v-shaped pH-rate profile, with the degradation rate minimum between pH 3 and 4. The moisture uptake and drug degradation increased with an increase in relative humidity. Solid-state stability indicated that the prodrug was stable at −18°C but demonstrated higher degradation at 4°C, 25°C and 40°C (51.6%, 74.5% and 90.1%, respectively) at the end of 3-months. THC-HG was found to be sensitive to the presence of oxygen. The release of the active from the polymeric matrices decreased, while bioadhesion increased, with an increase in molecular weight of PEO.     

Impact of food concentration on diel vertical migration behaviour of <Emphasis Type="Italic">Daphnia pulex</Emphasis> under fish predation risk

Vertical migration of Daphnia represents the best-studied predator-avoidance behaviour known; yet the mechanisms underlying the choice to migrate require further investigation to understand the role of environmental context. To investigate the optimal habitat choice of Daphnia under fish predation pressure, first, we selected the individuals exhibiting strong migration behaviour. The animals collected from the hypolimnion during the daytime were significantly larger, being more conspicuous, and in turn performed stronger diel vertical migration (DVM) when exposed to fish cue. We called them strong migrants. Second, we provided the strong migrant D. pulex with food at high and intermediate (1 and 0.4 mg C l⁻¹, respectively) levels, which were well above the incipient limiting level and of high quality. They traded the benefits of staying in the warm water layer and moved down to the cold water in response to fish cue indicating fish predation. The availability of food allowed the animals to stay in the cold hypolimnion. However, at the low food level (0.1 mg C l⁻¹), which is an additional constraint on fitness, Daphnia moved away from the cold hypolimnion. Poor food condition resulted in strong migrant Daphnia to cease migration and remain in the upper warmer water layer. Although temperature is known to be a more important cost factor of DVM than food, our results clearly show that this is only true as long as food is available. It becomes clear that food availability is controlling the direction of vertical positioning when daphnids experience a dilemma between optimising temperature and food condition while being exposed to fish cue. Then they overlook the predation risk. Thus, the optimal habitat choice of Daphnia appears to be a function of several variables including temperature, food levels and fish predation. Handling editor: S. I. Dodson     

PAMP-triggered immunity: Early events in the activation of FLAGELLIN SENSITIVE2

The Arabidopsis FLAGELLIN SENSITIVE2 (FLS2) protein is a leucine-rich repeat receptor-like kinase (LRR-RLK) that plays important roles in pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI). The binding of bacterial flagellin, one of the PAMPs, to the extracellular domain of FLS2 leads to activation of signaling cascades resulting in activation or repression of a specific set of genes involved in plant defense. The mechanisms at the cell membrane that lead to the activation of this signalling pathway are, however, not fully understood. Recently, we have shown that after ligand-treatment the mobility of FLS2 in the cell membrane is reduced and that the activation of FLS2 does not involve its constitutive or ligand-dependent homodimerization. Our data together with recently published reports suggest that FLS2 activation involves its association with other proteins, including BRI1-associated kinase 1 (BAK1), another LRR-RLK, and localization to less mobile areas, probably lipid rafts, in a ligand-dependent manner to initiate PTI.Key words: PTI, BiFC, flg22, FLS2, FRAP, FRET, membrane protein, RLK     

Effects of Aphid Prey on Larval Development and Mortality of Adalia bipunctata and Coccinella septempunctata (Coleoptera: Coccinellidae)

Developmental time and mortality rate of Adalia bipunctata (L.) and Coccinella septempunctata L. (Coleoptera: Coccinellidae) were determined when feeding on five aphid species. Metopolophium dirhodum (Walker), Sitobion avenae (F.), Rhopalosiphum padi (L.), Hyalopterus pruni (Geoffr.) and Myzus cerasi F. (Homoptera: Aphididae) are widespread in Tekirda?, Turkey. Tests were carried out in a controlled environmental chamber (25±1°C temperature, 65±5% relative humidity and 16 h light:8 h dark period). Developmental times for A. bipunctata and C. septempunctata larvae varied significantly depending on species of aphid prey (P<0.05). Development time (±S.E.) varied from 17.50±0.84 to 20.83±1.60 days for C. septempunctata and 16.7±0.76 to 20.7±1.03 days for A. bipunctata. Mortality of A. bipunctata (50%) and C. septempunctata (63%) were highest on H. pruni.     

Challenges in recruiting older twins for the Sri Lankan twin registry.

The National Twin Registry of Sri Lanka was established in 1997 as a volunteer register. To extend it to a population-based register, we examined the effectiveness of tracing older twins by inspecting birth records and recruiting them by postal invitation and in-person contact. Birth records at a divisional secretariat reported from 2 maternity hospitals between the years of 1954-1970 were scrutinised to identify a random sample of twins. These hospitals had the highest twin delivery rates for the whole country. We identified 620 twins and a questionnaire was mailed to them. Research assistants visited a cohort of non-respondents (71) in the postal survey. These 620 twins were identified after perusing 20700 birth records. The twinning rate was estimated at 29.95 ([620/20700] x 1000) twins per 1000 registered births (CI 27.63-32.27). In the postal survey, 37 (12%) responded and 62 letters were returned (20%). Both twins were still alive in 20 pairs, one was still alive in 15 pairs, and both twins were dead in 2 pairs. During field visits, 42 (59.2%) addresses were located. Information was available on 16 twin pairs. Both twins were alive in 8 pairs, one each in 4 pairs, and both were dead in 4 pairs and at least one twin was traced in 10 pairs (14%). Both the postal and the field survey gave a low yield. This finding is different from tracing younger twins born between 1985-1997 by using the same methods. Migration, urbanization and development in the country might have affected tracing older twins from the birth record addresses, which were decades old.     

New development for combined bioscouring and bleaching of cotton-based fabrics

A thorough investigation into conditions appropriate for effecting combined eco-friendly bioscouring and/or bleaching of cotton-based fabrics was undertaken. Fabrics used include cotton, grey mercerized cotton, cotton/polyester blend 50/50 and cotton/polyester blend 35/65. The four cotton-based fabric were subjected to bioscouring by single use of alkaline pectinase enzymes or by using binary mixtures of alkaline pectinase and cellulase enzymes under a variety of conditions. Results of bioscouring show that, the bioscoured substrates exhibit fabrics performances which are comparable with these of the conventional alkali scouring. It has been also found that, incorporation of ethylenediaminetetraacetic acid (EDTA) in the bioscouring with mixture from alkaline pectinase and cellulase improves the performance of the bioscoured fabrics. Addition of β-cyclodextrin to the bioscouring solution using alkaline pectinase in admixtures with cellulase acts in favor of technical properties and performance of the bioscoured fabrics. Concurrent bioscouring and bleaching by in situ formed peracetic acid using tetraacetylethylenediamine (TAED) and H₂O₂ was also investigated. The results reveal unequivocally that the environmentally sound technology brought about by current development is by far the best. The new development involves a single-stage process for full purification/preparation of cotton textiles. The new development at its optimal comprises treatment of the fabric with an aqueous formulation consisting of alkaline pectinase enzyme (2 g/L), TAED (15 g/L), H₂O₂ (5 g/L), nonionic wetting agent (0.5 g/L) and sodium silicate (2 g/L). The treatment is carried out at 60 °C for 60 min. Beside the advantages of the new development with respect to major technical fabric properties, it is eco-friendly and reproducible. This advocates the new development for mill trials.     

Cytotoxic activity of 4'-hydroxychalcone derivatives against Jurkat cells and their effects on mammalian DNA topoisomerase I

Chalcones (1,3-diaryl-2-propen-1-ones) are alpha, beta-unsaturated ketones with cytotoxic and anticancer properties. Several reports have shown that compounds with cytotoxic properties may also interfere with DNA topoisomerase functions. Five derivatives of 4'-hydroxychalcones were examined for cytotoxicity against transformed human T (Jurkat) cells as well as plasmid supercoil relaxation experiments using mammalian DNA topoisomerase I. The compounds were 3-phenyl-1-(4'-hydroxyphenyl)-2-propen-1-one (I), 3-(p-methylphenyl)-1-(4'-hydroxyphenyl)-2-propen-1-one (II), 3-(p-methoxyphenyl)-1-(4'-hydroxyphenyl)-2-propen-1-one (III), 3-(p-chlorophenyl)-1-(4'-hydroxyphenyl)-2-propen-1-one (IV), and 3-(2- thienyl)-1-(4'-hydroxyphenyl)-2-propen-1-one (V). The order of the cytotoxicity of the compounds was; IV > III > II > I > V. Compound IV, had the highest Hammett and log P values (0.23 and 4.21, respectively) and exerted both highest cytotoxicity and strongest DNA topoisomerase I inhibition. Compounds I and II gave moderate interference with the DNA topoisomerase I while III & V did not interfere with the enzyme.