Coagulant fixatives and paraffin embedding were widely used in the past for histomorphometrical evaluations of the human testis under physiological and pathological conditions. However, new methods ...are applied nowadays using better combinations of fixatives and plastic resins as embedding media, improving cell and tissue structural preservation. In an attempt to compare old and new data, the present study evaluated histomorphometrical data obtained from human testis after three different histological processing methods: Bouin/paraplast, glutaraldehyde/glycol methacrylate and glutaraldehyde/araldite. The morphometrical parameters were not affected by glutaraldehyde fixation after both resin embedding (methacrylate or araldite). On the other hand, Bouin/paraplast embedding lead to tissue shrinkage, which could give rise to misinterpretations on the measurements performed. Since some germ and somatic cells recognition do not depend upon high resolution techniques, counting of such cell types could be performed even using routine Bouin/paraplast protocols. Thus, the morphometrical analyses relying on cell recognition were not affected by the methods here applied, however, when metric measurements were applied, the obtained results could not be promptly compared. However, if the study requires confident spermatogonial identification for kinetics evaluation, glutaraldehyde/araldite processing is highly recommended.
Permeability/performance reference compounds (PRCs) are analytically noninterfering organic compounds with moderate to high fugacity from semipermeable membrane devices (SPMDs) that are added to the ...lipid prior to membrane enclosure. Assuming that isotropic exchange kinetics (IEK) apply and that SPMD−water partition coefficients are known, measurement of PRC dissipation rate constants during SPMD field exposures and laboratory calibration studies permits the calculation of an exposure adjustment factor (EAF). In theory, PRC-derived EAF ratios reflect changes in SPMD sampling rates (relative to laboratory data) due to differences in exposure temperature, membrane biofouling, and flow velocity−turbulence at the membrane surface. Thus, the PRC approach should allow for more accurate estimates of target solute/vapor concentrations in an exposure medium. Under some exposure conditions, the impact of environmental variables on SPMD sampling rates may approach an order of magnitude. The results of this study suggest that most of the effects of temperature, facial velocity−turbulence, and biofouling on the uptake rates of analytes with a wide range of hydrophobicities can be deduced from PRCs with a much narrower range of hydrophobicities. Finally, our findings indicate that the use of PRCs permits prediction of in situ SPMD sampling rates within 2-fold of directly measured values.
In Vitro and in Vivo Antischistosomal Activities of Chalcones Pereira, Vinícius R. D.; Junior, Ismael J. Alves; da Silveira, Lígia S. ...
Chemistry & biodiversity,
December 2018, 2018-Dec, 2018-12-00, 20181201, Letnik:
15, Številka:
12
Journal Article
Recenzirano
In this study, we evaluated the in vitro and in vivo schistosomicidal activities of chalcones against Schistosoma mansoni worms. In vitro assays revealed that chalcones 1 and 3 were the most active ...compounds, without affecting significantly mammalian cells. Confocal laser scanning microscopy and scanning electron microscopy studies revealed reduction on the numbers of tubercles and morphological alterations in the tegument of S. mansoni worms after in vitro incubation with chalcones 1 and 3. In a mouse model of schistosomiasis, the oral treatment (400 mg/kg) with chalcone 1 or 3 significantly caused a total worm burden reduction in mice. Chalcone 1 showed significant inhibition of the S. mansoni ATP diphosphohydrolase activity, which was corroborated by molecular docking studies. The results suggested that chalcones could be explored as lead compounds with antischistosomal properties.
Centratherin is a sesquiterpene lactone that has the potential to inhibit target proteins for cancer therapy, such as the inflammatory mediator NF-κB. Indoles also exhibit antitumoral activity and ...can modulate the NF-κB signaling pathway. Here we describe a molecular-docking guided semi-synthesis of indole-containing centratherin derivatives. In silico studies indicated that these compounds have high affinity to NF-κB and do not present toxicity or carcinogenicity. Two enantiomeric series of indole-centratherin hybrids were synthesized in three steps with good yields and ee, employing an organocatalyzed Friedel-Crafts alkylation as a key step. The compounds were evaluated against human leukemia K562 cells and showed promising antitumoral activities with IC50 ranging from 0.49 to 7.83 μM.
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•Centratherin is a sesquiterpene lactone potentially inhibiting target proteins for cancer therapy, including NF-κB.•Indoles demonstrate antitumoral activity and can modulate the NF-κB signaling pathway.•Molecular-docking guided semi-synthesis of indole-centratherin hybrids is described using organocatalyzed Friedel-Crafts alkylation as a key step.•The compounds exhibited promising antitumoral activities against K562 cells with IC50 ranging from 0.49 to 7.83 μM.
Indigenous societies are known to have occupied the Amazon basin for more than 12,000 years, but the scale of their influence on Amazonian forests remains uncertain. We report the discovery, using ...LIDAR (light detection and ranging) information from across the basin, of 24 previously undetected pre-Columbian earthworks beneath the forest canopy. Modeled distribution and abundance of large-scale archaeological sites across Amazonia suggest that between 10,272 and 23,648 sites remain to be discovered and that most will be found in the southwest. We also identified 53 domesticated tree species significantly associated with earthwork occurrence probability, likely suggesting past management practices. Closed-canopy forests across Amazonia are likely to contain thousands of undiscovered archaeological sites around which pre-Columbian societies actively modified forests, a discovery that opens opportunities for better understanding the magnitude of ancient human influence on Amazonia and its current state.
Editor’s summary
Indigenous societies have lived in the Amazon for at least 12,000 years. Finding evidence of these societies, however, has been greatly hampered by the density of the forest in Amazonia. Peripato
et al
. used LIDAR (light detection and ranging) surveys to identify more than 20 previously unidentified developments and then modeled the occurrence of others across the Amazon. The authors predict that between 10,000 and 24,000 ancient earthworks are waiting to be discovered. Sampling of some of the LIDAR transects revealed a consistent set of domesticated tree species associated with the developments, suggesting active forestry practices among these societies. —Sacha Vignieri
Amazon-wide LIDAR surveys and predictive models suggest thousands of undocumented archaeological sites across the basin.
The microbiological diversity was evaluated in an aerated facultative lagoon system with organic loading rates of 0.2 and 0.6 kgCODm-3d-1 treating effluent from the kraft pulp industry for ...bioaugmentation purposes. Samples were taken from a laboratory-scale lagoon at steady state treating kraft pulp effluent and operated with two different rates for 120 days. The analysis was performed by 16S rDNA sequencing. The autochthonous bacteria were identified through statistical similarity obtained from the NCBI-BLAST database. The lagoon performance was assessed based on the removal efficiency of biochemical oxygen demand (94% and 80%), chemical oxygen demand (51% and 44%), total organic carbon (49% and 41%), lignin-derived compounds (13% and 27%), turbidity (94% and 87%), for the low and high rates used respectively. Color and TPC were not significantly removed during the biological treatment of the industrial matrix. In the biomass samples collected at a steady state, 9 and 12 species of bacteria were identified at the applied rates. The species Bacillus cereus, Bacillus thuringiensis, and Paenibacillus glucanolyticus found in this matrix presented significant removal of the parameters in the kraft effluent. The three referred species show great promise in the removal of specific parameters in an AFL biological treatment system using bioaugmentation.
The objective of this study was to evaluate the influence of vascular architecture of broad ligament of the uterus on fetal and placental development in gilts. Fifteen gilts DB-90 (DanBred) were ...divided into three groups according to gestational age at slaughter (50, 80, and 106 days). After slaughter, fetuses and placentas were collected, weighed, and measured. The uterine arterial system was detached by latex repletion for quantification of the number and diameter of the terminal vessels in different regions of the uterine horns (apex, middle region, and base). Fetal and placental measurements were statistically analyzed and correlated with the number and diameter of arteries in each uterine segment. No correlation was observed (P > 0.10) between the number and diameter of arteries destined to the uterus with the number or weight of fetuses or placental weight in any gestational group. It was observed (P < 0.05) that more vessels destined to the medium region of the uterine horns, independent of the gestational age or uterus side. At the 80th day of gestation, fetuses located at the base of the uterus have (P < 0.05) smaller cephalic and thoracic perimeters. It was concluded that there were differences in vascularization of broad ligament that irrigates the different uterine segments, but this was not sufficient to influence the development of fetuses in gilts. The middle region of the uterine horns was the segment with a greater number of vessels, regardless of gestational age.
High quality fixation often inactivates epitopes and gentler fixation can fail to preserve biological structure at the required resolution. For studies of male reproduction, immunofluorescence ...techniques using paraformaldehyde fixation associated with paraffin as an embedding medium gives good epitope preservation, although the cell becomes morphologically compromised. On the other hand, glutaraldehyde associated with a plastic resin has been used with success to recognize and distinguish each spermatogonial cell subtype, but the antigenic sites become inaccessible to antibodies. Here we describe a new method that provides excellent morphological details of testicular cells while preserving the binding capacity of epitopes. Using a combination of glutaraldehyde and paraformaldehyde as a fixative and LR White resin for embedding, we show that it is possible to clearly recognize spermatogonial subtypes (Aund, A–A4, In and B spermatogonia) on 1-μm thick-sections and to label epitopes such as bromodeoxyuridine, a marker used for cellular cycle studies in the testis. The information gained from this procedure can be critical for understanding spermatogonial process of self-renewal and differentiation.
Late-onset sepsis (LOS) is an important cause of morbidity and mortality in very low birth weight (VLBW) infants.
To determine the incidence, risk factors and etiology of LOS.
LOS was investigated in ...a multicenter prospective cohort of infants at eight public university neonatal intensive care units (NICUs). Inclusion criteria included inborn, 23-33 weeks of gestational age, 400-1499 g birth weight, who survived >3 days.
Of 1507 infants, 357 (24%) had proven LOS and 345 (23%) had clinical LOS. Infants with LOS were more likely to die. The majority of infections (76%) were caused by Gram-positive organisms. Independent risk factors for proven LOS were use of central venous catheter and mechanical ventilation, age at the first feeding and number of days on parenteral nutrition and on mechanical ventilation.
LOS incidence and mortality are high in Brazilian VLBW infants. Most risk factors are associated with routine practices at NICU.
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