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1.
Glob Chang Biol ; 29(11): 3054-3071, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-36946870

RESUMEN

Climate change-related heatwaves are major threats to biodiversity and ecosystem functioning. However, our current understanding of the mechanisms governing community resistance to and recovery from extreme temperature events is still rudimentary. The spatial insurance hypothesis postulates that diverse regional species pools can buffer ecosystem functioning against local disturbances through the immigration of better-adapted taxa. Yet, experimental evidence for such predictions from multi-trophic communities and pulse-type disturbances, like heatwaves, is largely missing. We performed an experimental mesocosm study to test whether species dispersal from natural lakes prior to a simulated heatwave could increase the resistance and recovery of plankton communities. As the buffering effect of dispersal may differ among trophic groups, we independently manipulated the dispersal of organisms from lower (phytoplankton) and higher (zooplankton) trophic levels. The experimental heatwave suppressed total community biomass by having a strong negative effect on zooplankton biomass, probably due to a heat-induced increase in metabolic costs, resulting in weaker top-down control on phytoplankton. While zooplankton dispersal did not alleviate the negative heatwave effects on zooplankton biomass, phytoplankton dispersal enhanced biomass recovery at the level of primary producers, providing partial evidence for spatial insurance. The differential responses to dispersal may be linked to the much larger regional species pool of phytoplankton than of zooplankton. Our results suggest high recovery capacity of community biomass independent of dispersal. However, community composition and trophic structure remained altered due to the heatwave, implying longer-lasting changes in ecosystem functioning.


Asunto(s)
Ecosistema , Plancton , Animales , Zooplancton/fisiología , Biodiversidad , Biomasa , Fitoplancton/fisiología , Cadena Alimentaria
2.
Int J Mol Sci ; 24(19)2023 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-37834092

RESUMEN

Lipophilic oligonucleotide conjugates represent a powerful tool for nucleic acid cellular delivery, and many methods for their synthesis have been developed over the past few decades. In the present study, a number of chemical approaches for the synthesis of different fork- and comb-like dodecyl-containing oligonucleotide structures were performed, including use of non-nucleotide units and different types of phosphate modifications such as alkyl phosphoramidate, phosphoryl guanidine, and triazinyl phosphoramidate. The influence of the number of introduced lipophilic residues, their mutual arrangement, and the type of formed modification backbone on cell penetration was evaluated. The results obtained indicate great potential in the developed chemical approaches, not only for the synthesis of complex oligonucleotide structures but also for the fine-tuning of their properties.


Asunto(s)
Guanidinas , Oligonucleótidos , Oligonucleótidos/química , Guanidina/química , Fosfatos
3.
J Psycholinguist Res ; 52(6): 2119-2133, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37480449

RESUMEN

The number of children with partial or total hearing loss is increasing every day, and most of them are undergoing cochlear implant surgery. The paper aims to assess the teaching competence of parents of children with cochlear implants. The study took one year (2022) in 1 [Almaty, Kazakhstan] kindergarten and 1 specialized school. Twenty-four parents of children (mean age 3.5 ± 0.5 years) and 20 parents of children of primary school age (10.0 ± 0.5 years) who underwent surgery at the age of 1-2 and 6-9 years were included in the study. A minimal number of parents had a high level of competence; sufficient competence was noticed among the two times larger number of parents; however, most of the parents had insufficient competence. The indicators of children were as follows: 3 children had a high level of listening perception; twice as many of them had a sufficient level; the same number had an insufficient level. There were more children with a low level, 3 times more than with a high level. A high level of pedagogical competence of parents correlated with a high level of children's auditory verbal abilities (on the scale of auditory ability integration). There was also a direct relationship with the level of speech development (on the scale of speech use) for children who had the surgery a year earlier. The obtained data can apply to the educational process for children with cochlear implants to improve their auditory and speech skills as quickly as possible. The involvement of parents in the education and rehabilitation of children with cochlear implants is crucial for the successful adaptation and development of the child. Parents can become irreplaceable partners of specialists and educational institutions, providing their children with optimal support and assistance on their way to the development of auditory and communication skills. To enhance parental competence in the area of auditory development of children with cochlear implants, it is recommended to participate in specialized educational programs designed for parents, offered by professionals and organizations. Additionally, actively engaging with educational resources, online materials, and informational communities is beneficial for acquiring up-to-date knowledge and receiving support from other parents, specialists, and experts.


Asunto(s)
Implantación Coclear , Implantes Cocleares , Sordera , Percepción del Habla , Niño , Humanos , Preescolar , Padres
4.
Bull Environ Contam Toxicol ; 110(5): 95, 2023 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-37184604

RESUMEN

The widespread application of pesticides in the territories of the former USSR still exerts negative impacts on their ecological status. In this regard, dedicated programs for monitoring persistent organic pollutants (POP) in humans are implemented in several countries. Our study aimed to assess the accumulation of organic pollutants in breast milk of women residing the Chukotka Autonomous Okrug (CAO). Organochlorine pesticides (OCP) and polychlorinated biphenyls (PCB) concentrations in breast milk samples were measured by gas chromatography-mass spectrometry (GC-MS). The POP concentrations in the samples varied from 13 ng/g lipid weight (lw) to 620.6 ng/g lw (median 58.3 ng/g lw). An assessment of health risk to infants fed breast milk from CAO women did not show any exceedance of the estimated daily intake (EDI). The results obtained are the indirect evidence of the presence of these compounds in the environment and their negative effects on ecosystems and human health.


Asunto(s)
Contaminantes Ambientales , Hidrocarburos Clorados , Plaguicidas , Bifenilos Policlorados , Humanos , Femenino , Contaminantes Ambientales/análisis , Leche Humana/química , Ecosistema , Hidrocarburos Clorados/análisis , Bifenilos Policlorados/análisis , Plaguicidas/análisis , Federación de Rusia , Monitoreo del Ambiente
5.
Parasitology ; 149(8): 1045-1056, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35570672

RESUMEN

Global warming is likely to lengthen the seasonal duration of larval release by parasites. We exposed freshwater mussel hosts, Anodonta anatina, from 2 high-latitude populations to high, intermediate and low temperatures throughout the annual cercarial shedding period of the sympatric trematodes Rhipidocotyle fennica and R. campanula, sharing the same transmission pathway. At the individual host level, under warmer conditions, the timing of the cercarial release in both parasite species shifted towards seasonally earlier period while its duration did not change. At the host population level, evidence for the lengthening of larvae shedding period with warming was found for R. fennica. R. campanula started the cercarial release seasonally clearly earlier, and at a lower temperature, than R. fennica. Furthermore, the proportion of mussels shedding cercariae increased, while day-degrees required to start the cercariae shedding decreased in high-temperature treatment in R. fennica. In R. campanula these effects were not found, suggesting that warming can benefit more R. fennica. These results do not completely support the view that climate warming would invariably increase the seasonal duration of larval shedding by parasites, but emphasizes species-specific differences in temperature-dependence and in seasonality of cercarial release.


Asunto(s)
Anodonta , Trematodos , Animales , Cercarias/fisiología , Humanos , Estaciones del Año , Temperatura , Trematodos/fisiología
6.
Parasitology ; 149(1): 35-43, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-35184786

RESUMEN

Temperature and intraspecific competition are important factors influencing the growth of all organisms, including parasites. The temperature increase is suggested to stimulate the development of parasites within poikilothermic hosts. However, at high parasite densities, this effect could be diminished, due to stronger intraspecific competition. Our study, for the first time, addressed the joint effects of warming and parasite abundances on parasite growth in poikilothermic hosts. The growth of the common fish parasite larvae (trematode Diplostomum pseudospathaceum) within the rainbow trout at different infection intensities and temperatures (15°C and 18°C) was experimentally investigated. The results showed that temperature was positively correlated with both parasite infection success and growth rates. The growth rates increased much more compared to those in many free-living poikilothermic animals. Atypically for a majority of parasites, D. pseudospathaceum larvae grow faster when abundant (Allee effect). The possible causes for this phenomenon (manipulation cost sharing, etc.) are discussed in this study. Importantly, limited evidence of the interaction between temperature and population density was found. It is likely that temperature did not change the magnitude of the Allee effect but affected its timing. The impact of these effects is supposed to become more pronounced in freshwater ecosystems under current climate changes.


Asunto(s)
Enfermedades de los Peces , Oncorhynchus mykiss , Parásitos , Trematodos , Infecciones por Trematodos , Animales , Ecosistema , Enfermedades de los Peces/parasitología , Interacciones Huésped-Parásitos , Oncorhynchus mykiss/parasitología , Temperatura , Infecciones por Trematodos/parasitología , Infecciones por Trematodos/veterinaria
7.
Int J Mol Sci ; 23(3)2022 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-35163757

RESUMEN

Much attention has been recently drawn to studying melatonin - a hormone whose synthesis was first found in the epiphysis (pineal gland). This interest can be due to discovering the role of melatonin in numerous physiological processes. It was the discovery of melatonin synthesis in endocrine organs (pineal gland), neural structures (Purkinje cells in the cerebellum, retinal photoreceptors), and immunocompetent cells (T lymphocytes, NK cells, mast cells) that triggered the evolution of new approaches to the unifield signal regulation of homeostasis, which, at the turn of the 21st century, lead to the creation of a new integral biomedical discipline - neuroimmunoendocrinology. While numerous hormones have been verified over the last decade outside the "classical" locations of their formation, melatonin occupies an exclusive position with regard to the diversity of locations where it is synthesized and secreted. This review provides an overview and discussion of the major data regarding the role of melatonin in various physiological and pathological processes, which affords grounds for considering melatonin as the "cornerstone" on which neuroimmunoendocrinology has been built as an integral concept of homeostasis regulation.


Asunto(s)
Linfocitos/metabolismo , Mastocitos/metabolismo , Melatonina/biosíntesis , Sistemas Neurosecretores/metabolismo , Animales , Homeostasis , Humanos
8.
Int J Mol Sci ; 23(7)2022 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-35408963

RESUMEN

This study evaluates the effects of five different peptides, the Epitalon® tetrapeptide, the Vilon® dipeptide, the Thymogen® dipeptide, the Thymalin® peptide complex, and the Chonluten® tripeptide, as regulators of inflammatory and proliferative processes in the human monocytic THP-1, which is a human leukemia monocytic cell line capable of differentiating into macrophages by PMA in vitro. These peptides (Khavinson Peptides®), characterized by Prof. Khavinson from 1973 onwards, were initially isolated from animal tissues and found to be organ specific. We tested the capacity of the five peptides to influence cell cultures in vitro by incubating THP-1 cells with peptides at certain concentrations known for being effective on recipient cells in culture. We found that all five peptides can modulate key proliferative patterns, increasing tyrosine phosphorylation of mitogen-activated cytoplasmic kinases. In addition, the Chonluten tripeptide, derived from bronchial epithelial cells, inhibited in vitro tumor necrosis factor (TNF) production of monocytes exposed to pro-inflammatory bacterial lipopolysaccharide (LPS). The low TNF release by monocytes is linked to a documented mechanism of TNF tolerance, promoting attenuation of inflammatory action. Therefore, all peptides inhibited the expression of TNF and pro-inflammatory IL-6 cytokine stimulated by LPS on terminally differentiated THP-1 cells. Lastly, by incubating the THP1 cells, treated with the peptides, on a layer of activated endothelial cells (HUVECs activated by LPS), we observed a reduction in cell adhesion, a typical pro-inflammatory mechanism. Overall, the results suggest that the Khavinson Peptides® cooperate as natural inducers of TNF tolerance in monocyte, and act on macrophages as anti-inflammatory molecules during inflammatory and microbial-mediated activity.


Asunto(s)
Lipopolisacáridos , Monocitos , Citocinas/metabolismo , Dipéptidos/farmacología , Células Endoteliales/metabolismo , Humanos , Lipopolisacáridos/metabolismo , Lipopolisacáridos/farmacología , Macrófagos/metabolismo , Monocitos/metabolismo , Células THP-1 , Factor de Necrosis Tumoral alfa/metabolismo
9.
Molecules ; 27(23)2022 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-36500450

RESUMEN

A novel polydentate chelating antioxidant ligand and series of organotin complexes on its base were synthesized and characterized by NMR 1H, 13C, 119Sn, IR spectroscopy, X-ray, and elemental analysis. Their antioxidant activity was evaluated in DPPH and NBT-tests, and as lipoxygenase inhibitory activity. It was shown that ligand alone is a radical scavenger, while introducing tin in the structure of the compound significantly decreases its activity. For the ligand alone the ability to strongly suppress the formation of advanced glycation end products (AGEs) was shown, which may be associated with the established antiradical activity. All synthesized compounds appeared to be moderate lipoxygenase inhibitors. The stability of compounds to hydrolysis under different pH was estimated. The ligand undergoes decomposition after about an hour, while organotin complexes on its base demonstrate vast stability, showing signs of decomposition only after 5 h of experimentation. Cytotoxicity of compounds was studied by standard MTT-test, which showed unorthodox results: the ligand itself demonstrated noticeable cytotoxicity while the introduction of organotin moiety either did not affect the toxicity levels or reduced them instead of increasing. Organotin complexes possess luminescence both as powders and DMSO solutions, its quantum yields reaching 67% in DMSO. The combination of luminescence with unique cytotoxic properties allows us to propose the synthesized compounds as perspective theranostic agents.


Asunto(s)
Antineoplásicos , Compuestos Orgánicos de Estaño , Ligandos , Antioxidantes/farmacología , Compuestos Orgánicos de Estaño/farmacología , Compuestos Orgánicos de Estaño/química , Antineoplásicos/farmacología , Espectroscopía de Resonancia Magnética
10.
Int J Mol Sci ; 22(11)2021 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-34070944

RESUMEN

Embryogenesis is a complex multi-stage process regulated by various signaling molecules including pineal and extrapineal melatonin (MT). Extrapineal MT is found in the placenta and ovaries, where it carries out local hormonal regulation. MT is necessary for normal development of oocytes, fertilization and subsequent development of human, animal and avian embryos. This review discusses the role of MT as a regulator of preimplantation development of the embryo and its implantation into endometrial tissue, followed by histo-, morpho- and organogenesis. MT possesses pronounced antioxidant properties and helps to protect the embryo from oxidative stress by regulating the expression of the NFE2L2, SOD1, and GPX1 genes. MT activates the expression of the ErbB1, ErbB4, GJA1, POU5F1, and Nanog genes which are necessary for embryo implantation and blastocyst growth. MT induces the expression of vascular endothelial growth factor (VEGF) and its type 1 receptor (VEGF-R1) in the ovaries, activating angiogenesis. Given the increased difficulties in successful fertilization and embryogenesis with age, it is of note that MT slows down ovarian aging by increasing the transcription of sirtuins. MT administration to patients suffering from infertility demonstrates an increase in the effectiveness of in vitro fertilization. Thus, MT may be viewed as a key factor in embryogenesis regulation, including having utility in the management of infertility.


Asunto(s)
Implantación del Embrión/efectos de los fármacos , Desarrollo Embrionario/efectos de los fármacos , Regulación del Desarrollo de la Expresión Génica/efectos de los fármacos , Melatonina/uso terapéutico , Ovario/metabolismo , Placenta/metabolismo , Animales , Embrión de Mamíferos , Desarrollo Embrionario/genética , Femenino , Glutatión Peroxidasa/genética , Glutatión Peroxidasa/metabolismo , Humanos , Infertilidad Femenina/genética , Infertilidad Femenina/metabolismo , Infertilidad Femenina/patología , Infertilidad Femenina/prevención & control , Melatonina/metabolismo , Factor 2 Relacionado con NF-E2/genética , Factor 2 Relacionado con NF-E2/metabolismo , Ovario/crecimiento & desarrollo , Glándula Pineal/crecimiento & desarrollo , Glándula Pineal/metabolismo , Embarazo , Receptor ErbB-4/genética , Receptor ErbB-4/metabolismo , Superóxido Dismutasa-1/genética , Superóxido Dismutasa-1/metabolismo , Factor A de Crecimiento Endotelial Vascular/genética , Factor A de Crecimiento Endotelial Vascular/metabolismo , Glutatión Peroxidasa GPX1
11.
Int J Mol Sci ; 22(4)2021 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-33669686

RESUMEN

The review summarizes the results of experimental and clinical studies aimed at elucidating the causes and pathophysiological mechanisms of the development of endocrine pathology in children. The modern data on the role of epigenetic influences in the early ontogenesis of unfavorable factors that violate the patterns of the formation of regulatory mechanisms during periods of critical development of fetal organs and systems and contribute to the delayed development of pathological conditions are considered. The mechanisms of the participation of melatonin in the regulation of metabolic processes and the key role of maternal melatonin in the formation of the circadian system of regulation in the fetus and in the protection of the genetic program of its morphofunctional development during pregnancy complications are presented. Melatonin, by controlling DNA methylation and histone modification, prevents changes in gene expression that are directly related to the programming of endocrine pathology in offspring. Deficiency and absence of the circadian rhythm of maternal melatonin underlies violations of the genetic program for the development of hormonal and metabolic regulatory mechanisms of the functional systems of the child, which determines the programming and implementation of endocrine pathology in early ontogenesis, contributing to its development in later life. The significance of this factor in the pathophysiological mechanisms of endocrine disorders determines a new approach to risk assessment and timely prevention of offspring diseases even at the stage of family planning.


Asunto(s)
Sistema Endocrino/fisiología , Melatonina/deficiencia , Niño , Ritmo Circadiano/fisiología , Femenino , Desarrollo Fetal , Feto/fisiología , Humanos , Redes y Vías Metabólicas , Embarazo
12.
Molecules ; 26(22)2021 Nov 22.
Artículo en Inglés | MEDLINE | ID: mdl-34834147

RESUMEN

Peptides are characterized by their wide range of biological activity: they regulate functions of the endocrine, nervous, and immune systems. The mechanism of such action of peptides involves their ability to regulate gene expression and protein synthesis in plants, microorganisms, insects, birds, rodents, primates, and humans. Short peptides, consisting of 2-7 amino acid residues, can penetrate into the nuclei and nucleoli of cells and interact with the nucleosome, the histone proteins, and both single- and double-stranded DNA. DNA-peptide interactions, including sequence recognition in gene promoters, are important for template-directed synthetic reactions, replication, transcription, and reparation. Peptides can regulate the status of DNA methylation, which is an epigenetic mechanism for the activation or repression of genes in both the normal condition, as well as in cases of pathology and senescence. In this context, one can assume that short peptides were evolutionarily among the first signaling molecules that regulated the reactions of template-directed syntheses. This situation enhances the prospects of developing effective and safe immunoregulatory, neuroprotective, antimicrobial, antiviral, and other drugs based on short peptides.


Asunto(s)
Metilación de ADN , Epigénesis Genética , Histonas/metabolismo , Péptidos/metabolismo , Transducción de Señal , Animales , Humanos
13.
Int J Mol Sci ; 21(21)2020 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-33143333

RESUMEN

Melatonin (MT) and sirtuins (SIRT) are geroprotective molecules that hold back the aging process and the development of age-related diseases, including cardiovascular pathologies. Buccal epithelium (BE) sampling is a non-invasive procedure, yielding highly informative material for evaluating the expression of genes and proteins as well as the synthesis of molecules. Among these, MT and SIRTs are valuable markers of the aging process and age-related pathologies. The purpose of this study was to examine age-related expression patterns of these signaling molecules, in particular MT, SIRT1, SIRT3, and SIRT6 in BE of subjects of different ages with and without arterial hypertension (AH). We used real-time polymerase chain reaction (RT-PCR) and immunofluorescence analysis by confocal microscopy. We found that MT immunofluorescence intensity in BE decreases with aging, more evidently in AH patients. SIRT3 and SIRT6 genes expression and immunofluorescence intensity in BE was decreased in aging controls. In AH patients, SIRT1, SIRT3, and SIRT6 gene expression and immunofluorescence intensity in BE was decreased in relation to age and in comparison with age-matched controls. In conclusion, the evaluation of MT and sirtuins in BE could provide a non-invasive method for appraising the aging process, also when accompanied by AH.


Asunto(s)
Envejecimiento/patología , Biomarcadores/metabolismo , Melatonina/metabolismo , Hipertensión Arterial Pulmonar/patología , Sirtuina 1/metabolismo , Sirtuina 3/metabolismo , Sirtuinas/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Envejecimiento/metabolismo , Estudios de Casos y Controles , Epitelio/metabolismo , Epitelio/patología , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Mucosa Bucal/metabolismo , Mucosa Bucal/patología , Pronóstico , Hipertensión Arterial Pulmonar/metabolismo
14.
Molecules ; 25(3)2020 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-32019204

RESUMEN

It was shown that AEDG peptide (Ala-Glu-Asp-Gly, Epitalon) regulates the function of the pineal gland, the retina, and the brain. AEDG peptide increases longevity in animals and decreases experimental cancerogenesis. AEDG peptide induces neuronal cell differentiation in retinal and human periodontal ligament stem cells. The aim of the study was to investigate the influence of AEDG peptide on neurogenic differentiation gene expression and protein synthesis in human gingival mesenchymal stem cells, and to suggest the basis for the epigenetic mechanism of this process. AEDG peptide increased the synthesis of neurogenic differentiation markers: Nestin, GAP43, ß Tubulin III, Doublecortin in hGMSCs. AEDG peptide increased Nestin, GAP43, ß Tubulin III and Doublecortin mRNA expression by 1.6-1.8 times in hGMSCs. Molecular modelling method showed, that AEDG peptide preferably binds with H1/6 and H1/3 histones in His-Pro-Ser-Tyr-Met-Ala-His-Pro-Ala-Arg-Lys and Tyr-Arg-Lys-Thr-Gln sites, which interact with DNA. These results correspond to previous experimental data. AEDG peptide and histones H1/3, H1/6 binding may be one of the mechanisms which provides an increase of Nestin, GAP43, ß Tubulin III, and Doublecortin neuronal differentiation gene transcription. AEDG peptide can epigenetically regulate neuronal differentiation gene expression and protein synthesis in human stem cells.


Asunto(s)
Epigénesis Genética , Encía/metabolismo , Células Madre Mesenquimatosas/metabolismo , Neurogénesis , Neuronas/metabolismo , Oligopéptidos/farmacología , Biosíntesis de Proteínas , Regulación de la Expresión Génica , Encía/citología , Encía/efectos de los fármacos , Humanos , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/efectos de los fármacos , Neuronas/citología , Neuronas/efectos de los fármacos
15.
Parasitology ; 146(1): 105-111, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-29898802

RESUMEN

Removal of parasite free-living stages by predators has previously been suggested an important factor controlling parasite transmission in aquatic habitats. Experimental studies of zooplankton predation on macroparasite larvae are, however, scarce. We tested whether trematode cercariae, which are often numerous in shallow waters, are suitable prey for syntopic zooplankters. Feeding rates and survival of freshwater cyclopoids (Megacyclops viridis, Macrocyclops distinctus), calanoids (Arctodiaptomus paulseni), cladocerans (Sida crystallina) and rotifers Asplanchna spp., fed with cercariae of Diplostomum pseudospathaceum, a common fish trematode, were studied. In additional long-term experiments, we studied reproduction of cyclopoids fed with cercariae. All tested zooplankton species consumed cercariae. The highest feeding rates were observed for cyclopoids (33 ± 12 cercariae ind-1 h-1), which actively reproduced (up to one egg clutch day-1) when fed ad libitum with cercariae. Their reproductive characteristics did not change significantly with time, indicating that cercariae supported cyclopoids' dietary needs. Mortality of rotifers and cladocerans was high (25-28% individuals) when exposed to cercariae in contrast to cyclopoids and calanoids (<2%). Cercariae clogged the filtration apparatus of cladocerans and caused internal injuries in predatory rotifers, which ingested cercariae. Observed trophic links between common freshwater zooplankters and cercariae may significantly influence food webs and parasite transmission in lentic ecosystems.


Asunto(s)
Conducta Predatoria/fisiología , Trematodos/crecimiento & desarrollo , Zooplancton/fisiología , Análisis de Varianza , Animales , Cercarias , Copépodos/fisiología , Cadena Alimentaria , Rotíferos/fisiología , Caracoles/parasitología
16.
J Org Chem ; 81(14): 5837-50, 2016 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-27258739

RESUMEN

Interaction of 4,5-dimethyl-2-(2-oxo-1,2-diphenyl)ethoxy-1,3,2-dioxaphospholane, bearing a carboxyl group in the γ-position with respect to the phosphorus atom and obtained from d,l-butanediol, with hexafluoroacetone (CCl4, -40 °C) leads to the simultaneous formation of regio- and stereoisomeric cage-like phosphoranes with phosphorus-carbon and phosphorus-oxygen bonds with a high stereoselectivity (>95%), whose structure was determined by 1D and 2D NMR spectroscopy and XRD. When stored as a solution in dichloromethane for one month, the PCO-isomer rearranges into the thermodynamically more stable POC-isomer of the cage-like phosphorane. Mild hydrolysis of the PCO/POC-isomers proceeds with a high chemoselectivity and leads to the formation of P(IV)-dioxaphospholane derivatives. Acidic hydrolysis of the POC-isomer leads to the formation of an oxirane derivative with an unexpectedly high stereoselectivity (>95%). DFT calculations (using the PBE functional) allowed us to obtain structures and energies of the initial phospholane, reaction products (PCO/POC-isomers), and an intermediate P(V)-oxaphosphirane.

17.
J Org Chem ; 80(3): 1375-86, 2015 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-25496019

RESUMEN

The reaction of 3-benzoylquinoxalin-2(1H)-ones with enamines (generated in situ from ammonium acetate and the corresponding methylaryl(hetaryl)ketones) proceeds smoothly to give the corresponding substituted 1-(pyrrolyl)benzimidazolone derivatives in moderate yields through the novel rearrangement of 3-benzoylquinoxalin-2(1H)-ones involving a dual cleavage of the C3═N4 and C2-C3 bonds under mild conditions.


Asunto(s)
Acetatos/química , Aminas/química , Bencimidazoles/química , Bencimidazoles/síntesis química , Cetonas/química , Quinoxalinas/química , Catálisis , Estructura Molecular , Estereoisomerismo
18.
Elife ; 132024 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-39283662

RESUMEN

Over the past several decades, a trend toward delayed childbirth has led to increases in parental age at the time of conception. Sperm epigenome undergoes age-dependent changes increasing risks of adverse conditions in offspring conceived by fathers of advanced age. The mechanism(s) linking paternal age with epigenetic changes in sperm remain unknown. The sperm epigenome is shaped in a compartment protected by the blood-testes barrier (BTB) known to deteriorate with age. Permeability of the BTB is regulated by the balance of two mTOR complexes in Sertoli cells where mTOR complex 1 (mTORC1) promotes the opening of the BTB and mTOR complex 2 (mTORC2) promotes its integrity. We hypothesized that this balance is also responsible for age-dependent changes in the sperm epigenome. To test this hypothesis, we analyzed reproductive outcomes, including sperm DNA methylation in transgenic mice with Sertoli cell-specific suppression of mTORC1 (Rptor KO) or mTORC2 (Rictor KO). mTORC2 suppression accelerated aging of the sperm DNA methylome and resulted in a reproductive phenotype concordant with older age, including decreased testes weight and sperm counts, and increased percent of morphologically abnormal spermatozoa and mitochondrial DNA copy number. Suppression of mTORC1 resulted in the shift of DNA methylome in sperm opposite to the shift associated with physiological aging - sperm DNA methylome rejuvenation and mild changes in sperm parameters. These results demonstrate for the first time that the balance of mTOR complexes in Sertoli cells regulates the rate of sperm epigenetic aging. Thus, mTOR pathway in Sertoli cells may be used as a novel target of therapeutic interventions to rejuvenate the sperm epigenome in advanced-age fathers.


Asunto(s)
Metilación de ADN , Células de Sertoli , Espermatozoides , Masculino , Animales , Células de Sertoli/metabolismo , Ratones , Espermatozoides/metabolismo , Espermatozoides/fisiología , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Diana Mecanicista del Complejo 1 de la Rapamicina/genética , Serina-Treonina Quinasas TOR/metabolismo , Ratones Noqueados , Diana Mecanicista del Complejo 2 de la Rapamicina/metabolismo , Diana Mecanicista del Complejo 2 de la Rapamicina/genética , Proteína Reguladora Asociada a mTOR/metabolismo , Proteína Reguladora Asociada a mTOR/genética , Ratones Transgénicos , Envejecimiento/fisiología , Envejecimiento/genética , Transducción de Señal , Proteína Asociada al mTOR Insensible a la Rapamicina/metabolismo , Proteína Asociada al mTOR Insensible a la Rapamicina/genética , Epigénesis Genética
19.
Biomedicines ; 12(9)2024 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-39335502

RESUMEN

Cellular aging is considered as one of the main factors implicated in female infertility. We evaluated the expression of senescence-associated secretory phenotype (SASP) markers and additional molecular factors in an in vitro model of cellular aging. We induced genotoxic stress (UVB/UVA ray irradiation) in primary human endometrial cells obtained from female subjects of young reproductive age (<35 years of age). We assessed the expression levels of IL-6, IL-8, IL-1α, MMP3, SIRT-1, SIRT-6, TERF-1, and CALR at the mRNA level by RT-qPCR and at the protein level by immunofluorescence and confocal microscopy in primary human endometrial cells upon induction of genotoxic stress and compared them to untreated cells. Statistically significant differences were found for the expression of SIRT-1, SIRT-6, and TERF, which were found to be decreased upon induction of cell senescence through genotoxic stress, while IL-6, IL-8, IL-1α, MMP3, and p16 were found to be increased in senescent cells. We propose that these molecules, in addition to SAS-linked factors, could represent novel markers, and eventually potential therapeutic targets, for the aging-associated dysfunction of the female reproductive system.

20.
J Immunoassay Immunochem ; 34(2): 180-96, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23537302

RESUMEN

Adiponectin (Adn) is a protein that circulates in the blood in several oligomeric forms, namely low-, medium-, and high-molecular-weight forms. Adn may serve as a risk factor for type 2 diabetes mellitus (T2DM). The aims of this work were (1) to produce monoclonal antibodies (MAbs) specific to different Adn oligomeric forms, (2) to design immunoassays suitable for measuring the Adn forms present in human blood, and (3) to investigate the changes in Adn forms that occur in patients with T2DM. Gel filtration, fluoroimmunoassays, and Western blotting were utilized as major techniques in this study. MAbs recognizing various oligomeric forms of Adn were obtained. Complexes between Adn and complement component C1q and between the low molecular weight form of Adn and albumin were described in human blood. A decrease in the total Adn and Adn-albumin complex levels in the blood of patients with T2DM and no difference in the levels of the Adn-C1q complex in comparison with healthy volunteers were demonstrated. An Adn94-Adn63 fluoroimmunoassay was selected as the technique that most accurately measured the mass ratio of Adn oligomers in blood samples, and an Adn214-Adn27 assay that measured the low-molecular-weight form of Adn only.


Asunto(s)
Adiponectina/sangre , Diabetes Mellitus Tipo 2/sangre , Inmunoconjugados/sangre , Adiponectina/química , Adulto , Anciano , Animales , Anticuerpos Monoclonales/biosíntesis , Anticuerpos Monoclonales/química , Estudios de Casos y Controles , Complemento C1q/química , Femenino , Humanos , Inmunoconjugados/química , Masculino , Ratones , Persona de Mediana Edad , Peso Molecular , Unión Proteica , Isoformas de Proteínas/sangre , Isoformas de Proteínas/química , Albúmina Sérica/química
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