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1.
Pharmaceutics ; 16(6)2024 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-38931934

RESUMO

In the treatment of experimental neurodegeneration with disaccharide trehalose, various regimens are used, predominantly a 2% solution, drunk for several weeks. We studied the effects of different regimens of dietary trehalose treatment in an amyloid-ß (Aß) 25-35-induced murine model of Alzheimer's disease (AD). Aß-treated mice received 2% trehalose solution daily, 4% trehalose solution daily (continuous mode) or every other day (intermittent mode), to drink for two weeks. We revealed the dose-dependent effects on autophagy activation in the frontal cortex and hippocampus, and the restoration of behavioral disturbances. A continuous intake of 4% trehalose solution caused the greatest activation of autophagy and the complete recovery of step-through latency in the passive avoidance test that corresponds to associative long-term memory and learning. This regimen also produced an anxiolytic effect in the open field. The effects of all the regimens studied were similar in Aß load, neuroinflammatory response, and neuronal density in the frontal cortex and hippocampus. Trehalose successfully restored these parameters to the levels of the control group. Thus, high doses of trehalose had increased efficacy towards cognitive impairment in a model of early AD-like pathology. These findings could be taken into account for translational studies and the development of clinical approaches for AD therapy using trehalose.

2.
Biochemistry (Mosc) ; 89(5): 883-903, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38880649

RESUMO

Immune system and bone marrow stromal cells play an important role in maintaining normal hematopoiesis. Lymphoid neoplasia disturbs not only development of immune cells, but other immune response mechanisms as well. Multipotent mesenchymal stromal cells (MSCs) of the bone marrow are involved in immune response regulation through both intercellular interactions and secretion of various cytokines. In hematological malignancies, the bone marrow stromal microenvironment, including MSCs, is altered. Aim of this study was to describe the differences of MSCs' immunological function in the patients with acute lymphoblastic leukemia (ALL) and diffuse large B-cell lymphoma (DLBCL). In ALL, malignant cells arise from the early precursor cells localized in bone marrow, while in DLBCL they arise from more differentiated B-cells. In this study, only the DLBCL patients without bone marrow involvement were included. Growth parameters, surface marker expression, genes of interest expression, and secretion pattern of bone marrow MSCs from the patients with ALL and DLBCL at the onset of the disease and in remission were studied. MSCs from the healthy donors of corresponding ages were used as controls. It has been shown that concentration of MSCs in the bone marrow of the patients with ALL is reduced at the onset of the disease and is restored upon reaching remission; in the patients with DLBCL this parameter does not change. Proliferative capacity of MSCs did not change in the patients with ALL; however, the cells of the DLBCL patients both at the onset and in remission proliferated significantly faster than those from the donors. Expression of the membrane surface markers and expression of the genes important for differentiation, immunological status maintenance, and cytokine secretion differed significantly in the MSCs of the patients from those of the healthy donors and depended on nosology of the disease. Secretomes of the MSCs varied greatly; a number of proteins associated with immune response regulation, differentiation, and maintenance of hematopoietic stem cells were depleted in the secretomes of the cells from the patients. Lymphoid neoplasia leads to dramatic changes in the functional immunological status of MSCs.


Assuntos
Linfoma Difuso de Grandes Células B , Células-Tronco Mesenquimais , Leucemia-Linfoma Linfoblástico de Células Precursoras , Humanos , Células-Tronco Mesenquimais/metabolismo , Células-Tronco Mesenquimais/imunologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/imunologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Linfoma Difuso de Grandes Células B/imunologia , Linfoma Difuso de Grandes Células B/patologia , Linfoma Difuso de Grandes Células B/metabolismo , Masculino , Adulto , Feminino , Pessoa de Meia-Idade , Células da Medula Óssea/imunologia , Proliferação de Células , Adulto Jovem
3.
Artigo em Inglês | MEDLINE | ID: mdl-38716826

RESUMO

Aim: To establish significant risk factors for the development of adverse drug effects (ADEs) in children and adolescents with an acute psychotic episode taking antipsychotics. Materials and Methods: The research team randomly selected 15 patient records each month for 3 years (2016-2018). Overall, 450 patient records were included (223 boys and 227 girls, mean age was 14.52 ± 2.21 years). Adverse effects were identified using the standard algorithm of the Global Trigger Tool method. A "trigger" is an indication that an adverse reaction is likely to occur, e.g., an antihistamine prescription on a prescribing list. When a trigger was detected, the case history was studied in further detail to confirm the occurrence of ADEs. We divided patients into two groups: the "children" group (under 12 years old) and the "adolescents" group (13 years and older). Data were analyzed using the statistical package IBM SPSS Statistics 23.0. Results: Of the 450 patient records, 402 (89.3%) had at least one trigger detected. In total, 126 case histories contained evidence of ADE (28%). The total number of ADEs per 1000 patient days was 5.39 and the number of ADEs per 100 admissions was 32.0. Among adolescents, two or more triggers per patient were significantly more frequently identified (61.3% vs. 44.6%; p = 0.001). ADEs were rare in "Children" compared with "Adolescents" (13.8% vs. 30.4%; p = 0.006). The logistic regression analysis confirmed high predictive role of "Adolescence" (odds ratio [OR] = 2.58; 95% confidence interval [CI] 1.22-5.4; p = 0.013), "Polypharmacy" (OR = 1.96; 95% CI 1.23-3.1; p = 0.004), and "First-life hospitalization" (OR = 2.17; 95% CI 1.34-3.48; p = 0.001) for ADE fact in patient records. Conclusion: We found that significant risk factors for ADEs to antipsychotics in patients with acute psychotic episode were adolescence (13 years and older), polypharmacy, and first-life hospitalization. The fact that children (i.e., younger than 13 years of age) are less likely to experience ADEs was not associated with high-risk drugs or higher doses in our study.

4.
Children (Basel) ; 11(5)2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38790586

RESUMO

Brain injury resulting from adverse events during pregnancy and delivery is the leading cause of neonatal morbidity and disability. Surviving neonates often suffer long-term motor, sensory, and cognitive impairments. Birth asphyxia is among the most common causes of neonatal encephalopathy. The integration of ultrasound, including Doppler ultrasound, and near-infrared spectroscopy (NIRS) offers a promising approach to understanding the pathology and diagnosis of encephalopathy in this special patient population. Ultrasound diagnosis can be very helpful for the assessment of structural abnormalities associated with neonatal encephalopathy such as alterations in brain structures (intraventricular hemorrhage, infarcts, hydrocephalus, white matter injury) and evaluation of morphologic changes. Doppler sonography is the most valuable method as it provides information about blood flow patterns and outcome prediction. NIRS provides valuable insight into the functional aspects of brain activity by measuring tissue oxygenation and blood flow. The combination of ultrasonography and NIRS may produce complementary information on structural and functional aspects of the brain. This review summarizes the current state of research, discusses advantages and limitations, and explores future directions to improve applicability and efficacy.

5.
Cureus ; 16(3): e56976, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38665702

RESUMO

Thorough knowledge of the anatomical variations of the arterial pattern of the upper limb is of high clinical importance in many medical fields, from surgery to nursery and anesthesiologic practice. During a routine dissection at the Anatomy Department of the Medical University of Plovdiv, a rare variation of the vascular system in the upper limb of a study cadaver was observed. The exhibited variation was the occurrence of a brachioradial artery (BRA) that ran along the main axis of the arm, superficially to the median nerve. After dissection of the cubital fossa, an unusually underdeveloped radial artery was also spotted. Per our knowledge, such a type of duplicate radial artery, the coexistence of a BRA and an underdeveloped radial artery has not been reported in the relevant literature on the topic. The underdeveloped radial artery gave a major branch, the recurrent radial artery, a branch usually given by the brachial artery or the BRA in case of a BRA variation. Variations in the arterial pattern could potentially give insight into the features of the embryological development of the vascular system.

6.
Artigo em Inglês | MEDLINE | ID: mdl-38673375

RESUMO

The increase in the popularity and use of electronic cigarettes (e-cigarettes) has consistently risen worldwide and has become associated with adverse health outcomes. This study has identified the attitudes and perceptions of undergraduate students who vape in three universities in Mexico. A cross-sectional study involving 495 participants was conducted using a survey from October to December 2023. Three universities in different states in Mexico collaborated with colleges in Yucatan, Durango, and Nuevo Leon, Mexico. Descriptive statistics include frequencies and percentages, and four logistic regression models were employed. In the sample, 31% and 17.54% of participants reported smoking and vaping, respectively. Students who reported vaping in the last month reported that their first experience with vaping was at an average of 17.3 years of age, and of those, 71.26% (n = 62) reported having vaped for over 100 days, while the remaining 38% reported vaping for between 2 and 100 days. Students from Veracruz and Yucatan began vaping at a younger age than in the central and northern regions. There is a need to educate students about the dangers of the chemicals in the liquids they use, the secondary exposure vapers, and the health dangers they pose.


Assuntos
Estudantes , Vaping , Humanos , Vaping/psicologia , México , Estudantes/psicologia , Estudantes/estatística & dados numéricos , Universidades , Masculino , Feminino , Adulto Jovem , Estudos Transversais , Adolescente , Adulto , Sistemas Eletrônicos de Liberação de Nicotina/estatística & dados numéricos , Conhecimentos, Atitudes e Prática em Saúde , Inquéritos e Questionários
7.
Plants (Basel) ; 13(6)2024 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-38592901

RESUMO

Dryas oxyodonta Yuz. is a perennial evergreen shrub from the Rosaceae family. D. oxyodonta thrives in subalpine and subarctic regions, as well as in highlands spanning from Central Asia to Siberia and Mongolia. Owing to a lack of information on its chemical composition, we conducted qualitative and quantitative chromatographic analyses on extracts from the leaves and flowers of D. oxyodonta sourced from various Siberian habitats. Employing high-performance liquid chromatography with photodiode-array detection and electrospray ionization triple-quadrupole mass spectrometric detection, we identified 40 compounds, encompassing gallotannins, hydroxycinnamates, procyanidins, catechins, flavonoids, and triterpenes. All Siberian populations of D. oxyodonta exhibited a notable abundance of phenolic compounds. Furthermore, we identified rare glycosides, such as sexangularetin and corniculatusin, as potential markers of the chemodiversity within the Dryas genus. Extracts from the flowers and leaves were effective scavengers of free radicals, including DPPH•, ABTS•+-, O2•-, and •OH radicals. Our findings unequivocally establish D. oxyodonta as a rich source of phenolic compounds with potent antioxidant activity, suggesting its potential utility in developing novel functional products.

8.
Dalton Trans ; 53(13): 6100-6111, 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38482568

RESUMO

To design high-energy-density materials of a new level, it is necessary to develop methods for the functionalization of energetic scaffolds, which will make it possible to tune their physicochemical and energetic properties. For this reason, we have elaborated an approach for synthesizing a new series of energetic cage compounds with advanced properties by introducing the N-cyano group into the polynitro hexaazaisowurtzitane framework. The structures of the obtained substances were fully characterized with a combination of methods, including multinuclear (1H, 13C{1H}, 14N, and 15N{1H}) NMR and IR spectroscopy, high-resolution mass spectrometry, X-ray diffraction analysis, electron microscopy and quantum chemical calculations. For the resulting compounds, thermal stability and safety tests were carried out, calorimetric and pycnometric measurements were performed, and the energetic potential was determined by high-temperature chemical equilibrium thermodynamic calculations. The new cyano derivatives have an acceptable density (up to 1.92 g cm-3) and a high enthalpy of formation (up to 2 MJ kg-1), which is 2 times that of the benchmark CL-20. The resistance of the target compounds to friction (up to 220 N) is the highest compared to CL-20 and its known analogues. 4,10-Dicyano-2,6,8,12-tetranitro-2,4,6,8,10,12-hexaazaisowurtzitane of the new series is the most thermally stable (a Tdec of 238 °C) among the known energetic polynitro hexaazaisowurtzitanes and is the first derivative of this family to surpass CL-20 in heat resistance. Moreover, the specific impulse for the novel materials showed an improvement of 6.5-13 s over CL-20.

9.
Molecules ; 29(3)2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38338398

RESUMO

Photonic glasses (PGs) based on the self-assembly of monosized nanoparticles can be an effective tool for realizing disordered structures capable of tailoring light diffusion due to the establishment of Mie resonances. In particular, the wavelength position of these resonances depends mainly on the morphology (dimension) and optical properties (refractive index) of the building blocks. In this study, we report the fabrication and optical characterization of photonic glasses obtained via a self-assembling technique. Furthermore, we have demonstrated that the infiltration of these systems with a green-emitting polymer enhances the properties of the polymer, resulting in a large increase in its photoluminescence quantum yield and a 3 ps growing time of the photoluminescence time decay Finally, the development of the aforementioned system can serve as a suitable low-cost platform for the realization of lasers and fluorescence-based bio-sensors.

10.
Molecules ; 29(3)2024 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-38338326

RESUMO

Deoxycholic acid derivatives containing various heterocyclic functional groups at C-3 on the steroid scaffold were designed and synthesized as promising dual tyrosyl-DNA phosphodiesterase 1 and 2 (TDP1 and TDP2) inhibitors, which are potential targets to potentiate topoisomerase poison antitumor therapy. The methyl esters of DCA derivatives with benzothiazole or benzimidazole moieties at C-3 demonstrated promising inhibitory activity in vitro against TDP1 with IC50 values in the submicromolar range. Furthermore, methyl esters 4d-e, as well as their acid counterparts 3d-e, inhibited the phosphodiesterase activity of both TDP1 and TDP2. The combinations of compounds 3d-e and 4d-e with low-toxic concentrations of antitumor drugs topotecan and etoposide showed significantly greater cytotoxicity than the compounds alone. The docking of the derivatives into the binding sites of TDP1 and TDP2 predicted plausible binding modes of the DCA derivatives.


Assuntos
Inibidores de Fosfodiesterase , Diester Fosfórico Hidrolases , Inibidores de Fosfodiesterase/química , Diester Fosfórico Hidrolases/metabolismo , Modelos Moleculares , Ácido Desoxicólico/farmacologia , Relação Estrutura-Atividade
11.
Protoplasma ; 261(1): 111-124, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37542569

RESUMO

The aim of this study was to investigate in detail the pollen wall ontogeny in Impatiens glandulifera, with emphasis on the substructure and the underlying mechanisms of development. Sporopollenin-containing pollen wall, the exine, consists of two parts, ectexine and endexine. By determining the sequence of developing substructures with TEM, we have in mind to understand in which way the exine substructure is connected with function. We have shown earlier that physical processes of self-assembly and phase separation are universally involved in ectexine development; currently, we try to clear up whether these processes participate in endexine development. The data received were compared with those on other species. The ectexine ontogeny of I. glandulifera followed the main stages observed in many other species, including the late tetrad stage named "Golden gates". It turned out that the same physico-chemical processes act in endexine development, especially expressed in aperture sites. Another peculiar phenomenon observed in exine development was the recurrency of micellar sequence at near-aperture and aperture sites where the periplasmic space is widened. It should be noted that, in the whole, the developmental substructures observed during the tetrad and early post-tetrad period are similar in species with columellate exines. Evidently, these basic physical processes proceed, reiterating again and again in different species, resulting in an enormous variety of exine structures on the base of a relatively modest number of genes. Granular and alveolar exines emerge on the base of the same basic processes but are arrested at spherical and cylindrical micelle mesophases correspondingly.


Assuntos
Impatiens , Pólen
12.
Inj Prev ; 30(1): 68-74, 2024 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-38050048

RESUMO

INTRODUCTION: Burns are a frequent injury in children and can cause great physical and psychological impairment. Studies have identified positive effects of prevention measures based on increase in knowledge or reduction in hazards. The main goal of burn prevention campaigns, however, is to prevent burns. Therefore, this review is focused on the effectiveness of prevention programmes on the rates of burns in children. METHODS: A literature search was performed on PubMed, Embase, CINAHL, Web of Science, Google Scholar and Scopus, including a reference-check. Included were studies which evaluated burn prevention programmes in terms of burn injury rate in children up to 19 years old. Studies specifically focused on non-accidental burns were excluded as well as studies with only outcomes such as safety knowledge or number of hazards. RESULTS: The search led to 1783 articles that were screened on title and abstract. 85 articles were screened in full text, which led to 14 relevant studies. Nine of them reported a significant reduction in burn injury rate. Five others showed no effect on the number of burn injuries. In particular, studies that focused on high-risk populations and combined active with passive preventive strategies were successful. CONCLUSION: Some prevention programmes appear to be an effective manner to reduce the number of burn injuries in children. However, it is essential to interpret the results of the included studies cautiously, as several forms of biases may have influenced the observed outcomes. The research and evidence on this subject is still very limited. Therefore, it is of great importance that future studies will be evaluated on a decrease in burns and bias will be prevented. Especially in low-income countries, where most of the burns in children occur and the need for effective prevention campaigns is vital.


Assuntos
Queimaduras , Criança , Humanos , Queimaduras/epidemiologia , Queimaduras/prevenção & controle , Fatores de Risco
13.
Nat Prod Res ; 38(1): 158-163, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-35921543

RESUMO

Gentianopsis is a small gentianaceous genus with a known ethnopharmacological focus as hepatoprotectors containing two underestimated species that are scientifically unexplored: Gentianopsis komarovii (Grossh.) Toyok., which is typical of the Far East, and Gentianopsis stricta (Klotzsch) Ikonn., which is grown in Central Asia. Application of the HPLC-PDA-ESI-tQ-MS/MS technique led to the identification of 28 compounds, such as iridoid glycosides, flavones and xanthones, with loganic acid, sweroside, loganin, secologanin, isoorientin-7-O-glucoside, luteolin-7-O-gentiobioside, chrysoeriol-7-O-glucoside and acacetin-7-O-glucoside being found in the genus for the first time. The extracts of G. komarovii and G. stricta demonstrated choleretic potential, strengthening the bile flow and the total content of bile acids, bilirubin and cholesterol in the bile. The most pronounced effects were observed for luteolin-7-O-glucoside and gentiabavaroside (gentiacaulein-1-O-primveroside), establishing them as the principle choleretics of both herbs. Based on the results, G. komarovii, G. stricta and some phenolic metabolites are prospective new choleretic drugs.


Assuntos
Colagogos e Coleréticos , Espectrometria de Massas em Tandem , Espectrometria de Massas em Tandem/métodos , Cromatografia Líquida de Alta Pressão/métodos , Glucosídeos/farmacologia , Fenóis/análise , Extratos Vegetais/farmacologia
14.
Behav Brain Res ; 454: 114651, 2023 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-37657512

RESUMO

Animal models of Alzheimer's disease (AD) induced by intracerebroventricular (ICV) or intrahippocampal (IH) administration of amyloid-beta (Aß) are widely used in current research. It remains unclear whether these models provide similar outcomes or mimic pathological mechanisms of AD equally. The aim of the work was to compare two models induced by ICV or IH administration of Aß25-35 oligomers to C57BL/6 mice. Parameters characterizing cognitive function (passive avoidance test), protein expression (IBA1, Aß, LC3-II) and expression of genes for neuroinflammation (Aif1, Lcn2, Nrf2), autophagy (Atg8, Becn1, Park2), or markers of neurodegeneration (Cst3, Insr, Vegfa) were analyzed. Сognitive deficits, amyloid accumulation, and neuroinflammatory response in the brain evaluated by the microglial activation were similar in both models. Thus, both ways of Aß administration appear to be equally suitable for modelling AD-like pathology in mice. Our findings strongly support the key role of Aß load and neuroinflammatory response in the hippocampus and frontal cortex for the progression of AD-like pathology and development of cognitive deficits. There were certain minor differences between the models in the mRNA level of genes involved in the processes of neuroinflammation, neurodegeneration, and autophagy. Modulating effects of the central administration of Aß25-35 on the mRNA expression of Aif1, Lcn2, Park2, and Vegfa genes in different brain structures were revealed. The effects occurred to be more pronounced with the ICV method compared with the IH method. These findings give insight into the processes at initial stages of Aß-induced pathology depending on a primary location of Aß oligomers in the brain.


Assuntos
Doença de Alzheimer , Animais , Camundongos , Doença de Alzheimer/induzido quimicamente , Peptídeos beta-Amiloides , Modelos Animais de Doenças , Inflamação , Camundongos Endogâmicos C57BL , Doenças Neuroinflamatórias
15.
Int J Mol Sci ; 24(17)2023 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-37686030

RESUMO

Synchronous electron diffraction/mass spectrometry was used to study the composition and structure of molecular forms existing in a saturated vapor of cobalt(II) oxopivalate at T = 410 K. It was found that monomeric complexes Co4O(piv)6 dominate in the vapor. The complex geometry possesses the C3 symmetry with bond lengths Co-Oc = 1.975(5) Å and Co-O = 1.963(5) Å, as well as bond angles Oc-Co-O = 111.8(3)°, Co-Oc-Co = 110.4(6)°, O-Co-O = 107.1(3)° in the central OcCo4 fragment and four OcCoO3 fragments. The presence of an open 3d shell for each Co atom leads to the possibility of the existence of electronic states of the Co4O(piv)6 complex with Multiplicities 1, 3, 5, 7, 9, 11, and 13. For them, the CASSCF and XMCQDPT2 calculations predict similar energies, identical shapes of active orbitals, and geometric parameters, the difference between which is comparable with the error of determination by the electron diffraction experiment. QTAIM and NBO analysis show that the Co-Oc and Co-O bonds can be attributed to ionic (or coordination) bonds with a significant contribution of the covalent component. The high volatility and simple vapor composition make it possible to recommend cobalt (II) oxopivalate as precursors in the preparation of oxide films or coatings in the CVD technologies. The features of the electronic and geometric structure of the Co4O(piv)6 complex allows for the conclude that only a very small change in energy is required for the transition from antiferromagnetically to ferromagnetically coupled Co atoms.


Assuntos
Cobalto , Eletrônica , Elétrons , Gases , Estrutura Molecular
16.
Int J Mol Sci ; 24(18)2023 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-37762607

RESUMO

Using a model of Parkinson's disease (PD) induced by the bilateral injection of neurotoxin 6-hydroxydopamine (6-OHDA) into rat brain substantia nigra (SN), we showed uridine to exert a protective effect associated with activation of the mitochondrial ATP-dependent potassium (mitoK-ATP) channel. Injection of 4 µg neurotoxin evoked a 70% decrease in the time the experimental animal spent on the rod in the RotaRod test, an increase in the amount of lipid peroxides in blood serum and cerebral-cortex mitochondria and the rate of reactive oxygen species formation, and a decrease in Ca2+ retention in mitochondria. Herewith, lymphocytes featured an increase in the activity of lactate dehydrogenase, a cytosolic enzyme of glycolysis, without changes in succinate-dehydrogenase activity. Structural changes occurring in the SN and striatum manifested themselves in the destruction of mitochondria, degeneration of neurons and synapses, and stratification of myelin sheaths in them. Subcutaneous injections of 30 µg/kg uridine for 22 days restored the neurotoxin-induced changes in these parameters to levels close to the control. 5-Hydroxydecanoate (5 mg/kg), a specific mitoK-ATP channel inhibitor, eliminated the beneficial effect of uridine for almost all characteristics tested, indicating the involvement of the mitoK-ATP channel in the protective effect of uridine. The mechanism of the protective effect of uridine and its therapeutic applications for the prevention and treatment of PD are discussed.


Assuntos
Neurotoxinas , Doença de Parkinson , Animais , Ratos , Oxidopamina , Uridina/farmacologia , Doença de Parkinson/tratamento farmacológico , Doença de Parkinson/etiologia , Encéfalo , Trifosfato de Adenosina
17.
Planta ; 258(2): 38, 2023 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-37410162

RESUMO

MAIN CONCLUSION: Our findings suggest a reconsideration of pollen wall ontogeny process, entailing examination of physical factors, which enable a new understanding of exine developmental processes as self-formation. The pollen wall, the most complex cell wall in plants, is especially interesting as a model of ontogeny in miniature. By a detailed study of each developmental stage of Campanula rapunculoides pollen wall, we aimed to understand the establishment of complex pollen walls and the underlying developmental mechanisms. Other aim was to compare our current observations with studies in other species to reveal the common principles. We also tried to analyse the reasons for commonalities in ontogenies of exines in remote species. TEM, SEM, comparative methods were used in this study. The sequence of events leading to exine emergence from early tetrad stage to maturity is as follows: the appearance of spherical micelles in the periplasmic space and de-mixing of the mixture in periplasm (condensed and depleted layers); appearance of plasma membrane invaginations and columns of spherical micelles inside condensed layer; appearance of rod-like units, pro-tectum and thin foot layer; the appearance of spiral substructure of procolumellae and of dendritic outgrowths on the tops of procolumellae, of vast depleted zone in aperture sites; formation of the endexine lamellae on the base of laminate micelles; gradual twisting of dendritic outgrowths (macromolecule chains) into clubs on the tops of columellae and into spines; final sporopollenin accumulation. Our observations are consistent with the sequence of self-assembling micellar mesophases. Complex organisation of the exine is established through processes of self-assembly operating together with another physical process-phase separation. After genomic determination of the exine building substances, purely physical processes which are not under direct genomic control play an important role after genomic control of constructive substances. The comparison of the underlying mechanisms of exine development in remote species occurred to be general and similar to crystallisation. Our ontogenetic experience has shown the commonality of pollen wall ontogenies in remote species.


Assuntos
Campanulaceae , Micelas , Pólen , Parede Celular
18.
Int J Mol Sci ; 24(14)2023 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-37511195

RESUMO

Cerebral ischemia, and, as a result, insult, attacks up to 15 million people yearly in the world. In this connection, the development of effective preventive programs and methods of therapy has become one of the most urgent problems in modern angiology and pharmacology. The cytoprotective action of taxifolin (TAX) in ischemia is well known, but its limitations are also known due to its poor solubility and low capacity to pass through the hematoencephalic barrier. Molecular mechanisms underlying the protective effect of TAX in complex systems such as the brain remain poorly understood. It is known that the main cell types of the brain are neurons, astrocytes, and microglia, which regulate the activity of each other through neuroglial interactions. In this work, a comparative study of cytoprotective mechanisms of the effect of TAX and its new water-soluble form aqua taxifolin (aqTAX) was performed on cultured brain cells under ischemia-like conditions (oxygen-glucose deprivation (OGD)) followed by the reoxygenation of the culture medium. The concentration dependences of the protective effects of both taxifolin forms were determined using fluorescence microscopy, PCR analysis, and vitality tests. It was found that TAX began to effectively inhibit necrosis and the late stages of apoptosis in the concentration range of 30-100 µg/mL, with aqTAX in the range of 10-30 µg/mL. At the level of gene expression, aqTAX affected a larger number of genes than TAX; enhanced the basic and OGD/R-induced expression of genes encoding ROS-scavenging proteins with a higher efficiency, as well as anti-inflammatory and antiapoptotic proteins; and lowered the level of excitatory glutamate receptors. As a result, aqTAX significantly inhibited the OGD-induced increase in the Ca2+ levels in the cytosol ([Ca2+]i) in neurons and astrocytes under ischemic conditions. After a 40 min preincubation of cells with aqTAX under hypoxic conditions, these Ca2+ signals were completely inhibited, resulting in an almost complete suppression of necrotic death of cerebral cortical cells, which was not observed with the use of classical TAX.


Assuntos
Isquemia Encefálica , Fármacos Neuroprotetores , Camundongos , Animais , Transdução de Sinais , Quercetina/farmacologia , Quercetina/metabolismo , Neurônios/metabolismo , Isquemia Encefálica/tratamento farmacológico , Isquemia Encefálica/metabolismo , Oxigênio/metabolismo , Glucose/metabolismo , Células Cultivadas , Isquemia/metabolismo , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/metabolismo , Sobrevivência Celular
19.
Metabolites ; 13(6)2023 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-37367847

RESUMO

α-Glucosidase inhibitors are essential in the treatment of diabetes mellitus. Plant-derived drugs are promising sources of new compounds with glucosidase-inhibiting ability. The Geum aleppicum Jacq. and Sibbaldianthe bifurca (L.) Kurtto & T.Erikss. herbs are used in many traditional medical systems to treat diabetes. In this study, metabolites of the G. aleppicum and S. bifurca herbs in active growth, flowering, and fruiting stages were investigated using high-performance liquid chromatography with photodiode array and electrospray ionization triple quadrupole mass spectrometric detection (HPLC-PDA-ESI-tQ-MS/MS). In total, 29 compounds in G. aleppicum and 41 components in S. bifurca were identified including carbohydrates, organic acids, benzoic and ellagic acid derivatives, ellagitannins, flavonoids, and triterpenoids. Gemin A, miquelianin, niga-ichigoside F1, and 3,4-dihydroxybenzoic acid 4-O-glucoside were the dominant compounds in the G. aleppicum herb, while guaiaverin, miquelianin, tellimagrandin II2, casuarictin, and glucose were prevailing compounds in the S. bifurca herb. On the basis of HPLC activity-based profiling of the G. aleppicum herb extract, the most pronounced inhibition of α-glucosidase was observed for gemin A and quercetin-3-O-glucuronide. The latter compound and quercetin-3-O-arabinoside demonstrated maximal inhibition of α-glucosidase in the S. bifurca herb extract. The obtained results confirm the prospects of using these plant compounds as possible sources of hypoglycemic nutraceuticals.

20.
Molecules ; 28(9)2023 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-37175075

RESUMO

Based on the data of the gas electron diffraction/mass spectrometry (GED/MS) experiment, the composition of the vapor over rhenium tetrafluoride at T = 471 K was established, and it was found that species of the Re2F8 is present in the gas phase. The geometric structure of the Re2F8 molecule corresponding to D4h symmetry was found, and the following geometric parameters of the rh1 configuration were determined: rh1(Re-Re) = 2.264(5) Å, rh1(Re-F) = 1.846(4) Å, α(Re-Re-F) = 99.7(0.2)°, φ(F-Re-Re-F) = 2.4 (3.6)°. Calculations by the self-consistent field in full active space approximation showed that for Re2F8, the wave function of the 1A1g ground electronic state can be described by the single closed-shell determinant. For that reason, the DFT method was used for a structural study of Re2X8 molecules. The description of the nature of the Re-Re bond was performed in the framework of Atom in Molecules and Natural Bond Orbital analysis. The difference in the experimental values of r(Re-Re) in the free Re2F8 molecule and the [Re2F8]2- dianion in the crystal corresponds to the concept of a triple σ2π4 (ReIV-ReIV) bond and a quadruple σ2π4δ2 (ReIII-ReIII) bond, respectively, which are formed between rhenium atoms due to the interaction of d-atomic orbitals. The enthalpy of dissociation of the Re2F8 molecular form in two monomers ReF4 (ΔdissH°(298) = 109.9 kcal/mol) and the bond energies E(Re-Re) and E(Re-X) in the series Re2F8→Re2Cl8→Re2Br8 molecules were estimated. It is shown that the Re-Re bond energy weakly depends on the nature of the halogen, while the symmetry of the Re2Br8 (D4d) geometric configuration differs from the symmetry of the Re2F8 and Re2Cl8 (D4h) molecules.

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