Variation in heat-shock proteins among species of desert fishes (Poeciliidae, Poeciliopsis)

Analysis of the heat-shock proteins (hsps) of six closely related species of Poeciliopsis demonstrated the existence of biochemical diversity in the hsp100, hsp70, hsp60, and hsp30 protein families among species. Each species expressed five to seven hsp70-related isoforms. Constitutive 70-kD isoforms were identical among species, but four different patterns of heat-inducible isoforms were seen in these six species. Members of the hsp70 family of molecular chaperones are included among the most highly conserved proteins known, and the possibility of variation in hsp70 among closely related species has rarely been addressed. The hsp30 family is known to be less conserved than the hsp70 family, and, as expected, the Poeciliopsis hsp30 patterns showed more variation. Most of the hsp30 isoforms characteristic of a particular species were unique to that species. Hsp100 and hsp60 were identical in five of the species, but alternate isoforms were found in P. monacha. The small size and limited geographical distribution of the P. monacha population have probably contributed to the uniqueness of the monacha pattern. Two of the species were shown to acquire thermotolerance, the ability to withstand normally lethal temperatures when subjected to a gradual temperature increase. Rapid-heating protocols commonly used to establish critical thermal maxima of organisms do not include this inducible component of thermoresistance and therefore do not adequately assess an organism's capacity to withstand thermal stress.      

The Use of Hydrophobic Adhesive Tape to Produce Miniature Wells on Microscope Slides

Hydrophobic adhesive tape was used to produce miniature wells on microscope slides for staining several sections of tissue with minimal amounts of cytochemical reagents. The wells could be tailored to individual specifications and the method allowed coverslips to be mounted close to the sections using either aqueous or xylene based mounting media. This method was especially useful for multiple immunolabelling of serial semithin cryosections.     

Validated spectrofluorimetric assay of two co-administered drug mixtures containing hydroxychloroquine with either moxifloxacin or ofloxacin as a drug regimen for hospital-acquired pneumonia in patients with COVID-19

Moxifloxacin and ofloxacin are two broad-spectrum quinolone antibiotics. They are among the most widely used antibiotics, at this time, applied to control the COVID-19 pandemic. Hydroxychloroquine is an FDA-approved drug for the treatment of COVID-19. This work describes a simple, green, selective, and sensitive spectrofluorimetric method for the assay of moxifloxacin and ofloxacin in the presence of hydroxychloroquine, two co-administered mixtures used in the treatment of hospital-acquired pneumonia in patients with COVID-19. Simultaneous assay of hydroxychloroquine and moxifloxacin was carried out in methanol using a direct spectrofluorimetric method (method I) at 375 and 550 nm, respectively, after excitation at 300 nm. The direct spectrofluorimetric assay was rectilinear over concentration ranges 50.0–400.0 and 300.0–2500.0 ng/ml for hydroxychloroquine and moxifloxacin, respectively, with limits of detection (LOD) of 6.4 and 33.64 ng/ml and limits of quantitation (LOQ) of 19.4 and 102.6 ng/ml, respectively, for the two drugs. The assay for hydroxychloroquine and ofloxacin was carried out by measuring the first derivative synchronous amplitude for hydroxychloroquine at the zero crossing point of ofloxacin and vice versa at Δλ = 140 nm (method II). Hydroxychloroquine was measured at 266 nm, while ofloxacin was measured at 340 nm over the concentration range 4–40 ng/ml for hydroxychloroquine and 200–2000 ng/ml for ofloxacin with LOD of 0.467 and 25.3 ng/ml and LOQ of 1.42 and 76.6 ng/ml, respectively, for the two drugs. The two methods were validated following International Conference on Harmonization guidelines and were applied to the analysis of the two drugs in plasma with good percentage recoveries (109.73–93.17%).     

New renin inhibitors homologous with pepstatin.

Four homologues of pepstatin, the potent but poorly soluble inhibitor of aspartic proteinases, were synthesized by coupling to the C-terminus of the natural pentapeptide the following amino acid residues: L-arginine methyl ester, L-aspartic acid, L-glutamic acid and the dipeptide L-aspartyl-L-arginine. The peptide-coupling reagent we used, benzotriazolyloxytris(dimethylamino)phosphonium hexafluorophosphate, allowed us to obtain readily pure pepstatin homologues with high yields (60-83%). Pepstatylarginine methyl ester and pepstatylglutamic acid were about one order of magnitude more water-soluble than pepstatin. The four homologues and pepstatin were tested in vitro as inhibitors for highly purified pig and human renins acting on the N-acetyltetradecapeptide substrate. The 50% inhibitory concentrations (IC50) of the homologues were ranged from 0.01 to 1 microM against porcine renin at pH 6.0 (pepstatin IC50 approximately 0.32 microM) and from 5.8 to 41 microM against human renin at pH 6.5 (pepstatin IC 50 approximately 17 microM). By three different graphical methods we showed that pepstatin and the four homologues behaved as competitive inhibitors for porcine renin. The most potent inhibitors were pepstatylaspartic acid and pepstatylglutamic acid, with inhibitory constants respectively 2- and 10-fold smaller than that of pepstatin. By coupling glutamic acid to pepstatin, the ratio solubility/Ki was increased by two orders of magnitude.     

Synthesis of some novel 6-benzyl(or substituted benzyl)-2-beta-D-glucopyranosyl-1,2,4-triazolo[4,3-b][1,2,4]triazines as potential antimicrobial chemotherapeutics

Glucosidation of the new 8-amino-6-benzyl(or substituted benzyl)-2,8-dihydro-1,2,4-triazolo[4,3-b][1,2,4]triazin-7(3H)-ones (3a-d) with 2,3,4,6-tetra-O-acetyl-alpha-D-glucopyranosyl bromide 4 gave the corresponding N-glucosides 5a-d. Chemical transformations leading to new functionalities have also been achieved to give compounds 7-12. Antimicrobial activity of compounds 5a-c against Aspergillus fumigatus, Penicillium italicum, Syncephalastrum racemosum, Candida albicans, Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis, Escherichia coli is described.     

Ten years primary succession on a newly created landfill at a lagoon of the Mediterranean Sea (Lake Burullus RAMSAR site)

This study was carried out on the transported bed soil dredged from the outlet of Lake Burullus to the Mediterranean Sea and deposited nearby, forming by this way new land that underwent a primary plant succession. The multi-methodological approach comprised floristic inventories, vegetation sampling and soil composition analyses of the study site in order to detect the crucial parameters controlling the plant resettlement on recently deposited soil as related to time, local micro-topography and substrate characteristics. Floristic composition was assessed for the first 10 years of primary succession (2001–2010) on 18 stands of the area, distributed on basement, slope stands and plateau of the landfill, respectively. Vegetation surveys were the basis of multivariate analyses of the vegetation and soil data using TWINSPAN, DCA and CCA. Relationships between the edaphic gradients, floristic composition and species diversity were assessed.     

Improving integrated management of weed control by determination of weed seed bank in sandy and clay soil

Knowledge of soil weed seed bank is important for population dynamics studied, establishment of appropriate weed management programs, a little effort in understanding weed seed bank can give valuable information about what weeds to expect in growing season, weed density, and when most weed germination will take place. In this study, a two - year''s, two sites were carried out with the aim of assessing weed seed bank status of the soil throughout 2018 and 2019. A site was worked out in Sakha Agriculture Research farm act as a clay soil, Kafr El-Sheikh Governorate, Agriculture Research Center (ARC). Another site was worked out in El-Ismailia Agr; Res; farm act as sandy soil, El-Ismailia Governorate, ARC. At each site, soil samples were selected from nine different places as like three Zigzag shapes divided into three, six and nine sites, “W” to act the whole soil area (30 faddan in Sakha farm, and 15 faddan in El-Ismailia farm). The soil samples were taken from topsoil 0–10 cm depth with an auger (core) 10 cm diameter the soils without tillage and before sowing the summer crop. The result of present the study in two different stations and soils, revealed that the number of soil samples to estimate weed seed banks should be either six or nine sites; each sample weighted 0.50 Kg soil with zigzag shape act a direct seed extraction technique to able recognize the abundance of weed species into the soil and their seed density. The aim is to improve integrated weed control.     

Interleukin-15 is a major regulator of the cell-microenvironment interactions in human renal homeostasis

Experiments in IL-15^?/? and IL-15Rα^?/? mice show that intra-renal IL-15, through IL-15Rα behaves as an epithelial survival factor. Recent data highlight new functions of IL-15 in renal homeostasis mediated by IL-15Rγ (CD132). Indeed, in CD132+ renal epithelial tubular cells IL-15 preserves E-cadherin expression inhibiting epithelial-mesenchymal transition (EMT). By contrast, during allograft rejection, the increased intra-graft IL-15 expression favors tubular destruction facilitating the intraepithelial recruitment of CD8 T cells expressing the E-cadherin ligand CD103. In renal cancer, loss of CD132 by epithelial cells defines a tumoral microenvironment where IL-15 triggers E-cadherin down-regulation and EMT. Finally, in CD132+ renal cancer stem cells IL-15 induces the generation of non-tumorigenic epithelial cells sensitive to cytotoxic drugs. These findings are discussed in the light of IL-15-based immunotherapy for renal cancer.     

A novel prenylated C6–C3 compound with estrogen-like activity from the fruits of Illicium arborescens

A novel C₆–C₃ prenylated compound, illicarborene A (1), together with illioliganfunone D (2), 1-allyl-3,5-dimethoxy-4-(3-methylbut-2-enyloxy)benzene (3), (?)-illicinone A (4), (?)-illicinone B (5) and (?)-illicinone A derivative (6) was isolated and characterized from the fruits of Illicium arborescens Hayata. Compound 1 possesses a new class of tricyclic 6/6/5 ring system. The structure of 1 was determined by spectroscopic analysis such as ¹H–¹H COSY, HMQC, HMBC, and NOESY, and confirmed by chemical reaction to yield 7. Compounds 1–5 were found to increase proliferative activity in primary cell culture of osteoblast cells.