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1.
Biomedicines ; 12(3)2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38540250

RESUMO

Retinal vascular diseases and consequential metabolic disturbances in the eye are major concerns for healthcare systems all around the world. BGP-15, a drug candidate small-molecule [O-(3-piperidino-2-hydroxy-1-propyl) nicotinic amidoxime dihydrochloride], has been formerly demonstrated by our workgroup to be retinoprotective both in the short and long term. Based on these results, the present study was performed to investigate the efficacy of BGP in an eyedrop formulation containing sulfobutylether-ß-cyclodextrin (SBECD), which is a solubility enhancer as well. Electroretinographical evaluations were carried out and BGP was demonstrated to improve both scotopic and photopic retinal a- and b-waves, shorten their implicit times and restore oscillatory potentials after ischemia-reperfusion. It was also observed to counteract retinal thinning after ischemia-reperfusion in the eyes of Sprague Dawley rats. This small-molecule drug candidate is able to compensate for experimental global eye ischemia-reperfusion injury elicited by ligation of blood vessels in rats. We successfully demonstrated that BGP is able to exert its protective effects on the retina even if administered in the form of eyedrops.

2.
Biomedicines ; 11(2)2023 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-36830799

RESUMO

The prevalence of Alzheimer's disorder (AD) is increasing worldwide, and the co-morbid anxiety is an important, albeit often neglected problem, which might appear early during disease development. Animal models can be used to study this question. Mice, as prey animals, show an innate defensive response against a predator odor, providing a valuable tool for anxiety research. Our aim was to test whether the triple-transgenic mice model of AD shows signs of innate anxiety, with specific focus on the temporal appearance of the symptoms. We compared 3xTg-AD mice bearing human mutations of amyloid precursor protein, presenilin 1, and tau with age-matched controls. First, separate age-groups (between 2 and 18 months) were tested for the avoidance of 2-methyl-2-thiazoline, a fox odor component. To test whether hypolocomotion is a general sign of innate anxiety, open-field behavior was subsequently followed monthly in both sexes. The 3xTg-AD mice showed more immobility, approached the fox odor container less often, and spent more time in the avoidance zone. This effect was detectable already in two-month-old animals irrespective of sex, not visible around six months of age, and was more pronounced in aged females than males. The 3xTg-AD animals moved generally less. They also spent less time in the center of the open-field, which was detectable mainly in females older than five months. In contrast to controls, the aged 3xTg-AD was not able to habituate to the arena during a 30-min observation period irrespective of their sex. Amyloid beta and phospho-Tau accumulated gradually in the hippocampus, amygdala, olfactory bulb, and piriform cortex. In conclusion, the early appearance of predator odor- and open space-induced innate anxiety detected already in two-month-old 3xTg-AD mice make this genetically predisposed strain a good model for testing anxiety both before the onset of AD-related symptoms as well as during the later phase. Synaptic dysfunction by protein deposits might contribute to these disturbances.

3.
Sci Rep ; 13(1): 1112, 2023 01 20.
Artigo em Inglês | MEDLINE | ID: mdl-36670139

RESUMO

Combination of the genomes of Saccharomyces species has great potential for the construction of new industrial strains as well as for the study of the process of speciation. However, these species are reproductively isolated by a double sterility barrier. The first barrier is mainly due to the failure of the chromosomes to pair in allodiploid meiosis. The second barrier ensures that the hybrid remains sterile even after genome duplication, an event that can restore fertility in plant interspecies hybrids. The latter is attributable to the autodiploidisation of the allotetraploid meiosis that results in sterile allodiploid spores (return to the first barrier). Occasionally, mating-competent alloaneuploid spores arise by malsegregation of MAT-carrying chromosomes. These can mate with cells of a third species resulting in aneuploid zygotes having at least one incomplete subgenome. Here we report on the construction of euploid three-species hybrids by making use of "rare mating" between a sterile S. kudriavzevii x S. uvarum allodiploid hybrid and a diploid S. cerevisiae strain. The hybrids have allotetraploid 2nScnSk nSu genomes consisting of complete sets of parental chromosomes. This is the first report on the production of euploid three-species Saccharomyces hybrids by natural mating, without genetic manipulation. The hybrids provide possibilities for studying the interactions of three allospecific genomes and their orthologous genes present in the same cell.


Assuntos
Saccharomyces , Saccharomyces/genética , Saccharomyces cerevisiae/genética , Hibridização Genética , Genoma Fúngico
4.
Artigo em Inglês | MEDLINE | ID: mdl-36674026

RESUMO

The COVID-19 pandemic has posed a huge challenge to the world in recent years. The development of vaccines that are as effective as possible and accessible to society offers a promising alternative for addressing the problems caused by this situation as soon as possible and to restore the pre-epidemic system. The present study investigated the preferences of residents in Hungary's second-largest city (Debrecen) for the COVID-19 vaccine. To achieve this aim, a discrete choice experiment was conducted with 1011 participants, and the vaccine characteristics included in the design of the experiment were determined by qualitative methods and a pilot survey: (1) country of origin; (2) efficiency; (3) side effect; and (4) duration of protection. During the data collection at three vaccination sites, respondents were asked to choose between three vaccine alternatives and one "no choice" option in eight decision situations. Discrete choice model estimations were performed using a random parameter logit (RPL) specification with the final model extended to include a latent variable measuring pandemic awareness. The results showed that the vaccine with a Chinese country of origin is the least preferred among the respondents, while the Hungarian and the European vaccines are the most preferred. Furthermore, the increase in the vaccine efficiency level increased the respondents' sense of utility for the vaccine; the short-term side effect was preferred to the long-term one; and the increase in the duration of protection provided by the vaccine increased the respondents' sense of utility for the vaccine. Based on the parameter estimated for the latent variable, it can be concluded that as the level of pandemic awareness (which is more positive among people with chronic diseases and less important among health workers) increases, the choice of a vaccine option becomes more preferred among respondents compared to the "no choice". The results of our investigation could contribute towards increasing compliance in the case of the vaccination-rejecting population, not only for COVID-19, but for any kind of vaccination procedure.


Assuntos
COVID-19 , Vacinas , Humanos , Vacinas contra COVID-19/uso terapêutico , Pandemias/prevenção & controle , Hungria , Comportamento de Escolha , COVID-19/epidemiologia , COVID-19/prevenção & controle , Vacinação
5.
Ann Thorac Surg ; 115(3): 778-783, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36470568

RESUMO

PURPOSE: The purpose of this study was to compare outcomes of Melody mitral valve to mechanical mitral valve replacement (MVR) for young children. DESCRIPTION: Children who underwent Melody MVR from 2014 to 2020 were case-matched to mechanical MVR patients. Transplant-free survival and cumulative incidence of reintervention were compared. A subanalysis was performed for infants aged < 1 year (9 Melody MVRs and their matches). EVALUATION: Twelve children underwent Melody MVR. Two children (17%) salvaged from mechanical support died. Five of 10 survivors (50%) had subsequent MVR. At 1 and 3 years, transplant-free survival (Melody: 83%, 83%; mechanical: 83%, 67%; P = .180) and reintervention (Melody: 9%, 39%; mechanical: 0%, 18%; P = .18) were equivalent between groups. For children < 1 year of age, Melody MVR had a modest survival benefit (Melody: 89%, 89%; mechanical: 80%, 60%; P = .046), while rate of reintervention remained equivalent (Melody: 13%, 32%; mechanical: 0%, 22%; P = .32). CONCLUSIONS: For patients < 1 year old, Melody MVR offers a promising alternative and is a reasonable bridge to mechanical MVR, which can be performed safely at an older age. Further studies are necessary to corroborate these findings.


Assuntos
Implante de Prótese de Valva Cardíaca , Próteses Valvulares Cardíacas , Insuficiência da Valva Mitral , Estenose da Valva Mitral , Lactente , Humanos , Criança , Pré-Escolar , Valva Mitral/cirurgia , Resultado do Tratamento , Insuficiência da Valva Mitral/cirurgia , Estenose da Valva Mitral/cirurgia , Estudos Retrospectivos
6.
Front Endocrinol (Lausanne) ; 13: 985424, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36303870

RESUMO

Alzheimer's disease is the most common type of dementia, being highly prevalent in elderly women. The advanced progression may be due to decreased hormone synthesis during post-menopause as estradiol and progesterone both have neuroprotective potentials. We aimed to confirm that female hormone depletion aggravates the progression of dementia in a triple transgenic mouse model of Alzheimer's disease (3xTg-AD). As pathological hallmarks are known to appear in 6-month-old animals, we expected to see disease-like changes in the 4-month-old 3xTg-AD mice only after hormone depletion. Three-month-old female 3xTg-AD mice were compared with their age-matched controls. As a menopause model, ovaries were removed (OVX or Sham surgery). After 1-month recovery, the body composition of the animals was measured by an MRI scan. The cognitive and anxiety parameters were evaluated by different behavioral tests, modeling different aspects (Y-maze, Morris water maze, open-field, social discrimination, elevated plus maze, light-dark box, fox odor, operant conditioning, and conditioned fear test). At the end of the experiment, uterus was collected, amyloid-ß accumulation, and the cholinergic system in the brain was examined by immunohistochemistry. The uterus weight decreased, and the body weight increased significantly in the OVX animals. The MRI data showed that the body weight change can be due to fat accumulation. Moreover, OVX increased anxiety in control, but decreased in 3xTg-AD animals, the later genotype being more anxious by default based on the anxiety z-score. In general, 3xTg-AD mice moved less. In relation to cognition, neither the 3xTg-AD genotype nor OVX surgery impaired learning and memory in general. Despite no progression of dementia-like behavior after OVX, at the histological level, OVX aggravated the amyloid-ß plaque deposition in the basolateral amygdala and induced early cholinergic neuronal fiber loss in the somatosensory cortex of the transgenic animals. We confirmed that OVX induced menopausal symptoms. Removal of the sexual steroids aggravated the appearance of AD-related alterations in the brain without significantly affecting the behavior. Thus, the OVX in young, 3-month-old 3xTg-AD mice might be a suitable model for testing the effect of new treatment options on structural changes; however, to reveal any beneficial effect on behavior, a later time point might be needed.


Assuntos
Doença de Alzheimer , Complexo Nuclear Basolateral da Amígdala , Animais , Camundongos , Feminino , Humanos , Doença de Alzheimer/patologia , Camundongos Transgênicos , Complexo Nuclear Basolateral da Amígdala/patologia , Modelos Animais de Doenças , Fibras Colinérgicas/patologia , Sintomas Comportamentais , Hormônios , Ovariectomia , Peso Corporal , Colinérgicos
8.
Int J Mol Sci ; 23(18)2022 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-36142737

RESUMO

Alzheimer's disease (AD) is a progressive neurodegenerative disorder and the most common form of dementia. Approximately 50% of AD patients show anxiety and depressive symptoms, which may contribute to cognitive decline. We aimed to investigate whether the triple-transgenic mouse (3xTg-AD) is a good preclinical model of this co-morbidity. The characteristic histological hallmarks are known to appear around 6-month; thus, 4- and 8-month-old male mice were compared with age-matched controls. A behavioral test battery was used to examine anxiety- (open field (OF), elevated plus maze, light-dark box, novelty suppressed feeding, and social interaction (SI) tests), and depression-like symptoms (forced swim test, tail suspension test, sucrose preference test, splash test, and learned helplessness) as well as the cognitive decline (Morris water maze (MWM) and social discrimination (SD) tests). Acetylcholinesterase histochemistry visualized cholinergic fibers in the cortex. Dexamethasone-test evaluated the glucocorticoid non-suppression. In the MWM, the 3xTg-AD mice found the platform later than controls in the 8-month-old cohort. The SD abilities of the 3xTg-AD mice were missing at both ages. In OF, both age groups of 3xTg-AD mice moved significantly less than the controls. During SI, 8-month-old 3xTg-AD animals spent less time with friendly social behavior than the controls. In the splash test, 3xTg-AD mice groomed themselves significantly less than controls of both ages. Cortical fiber density was lower in 8-month-old 3xTg-AD mice compared to the control. Dexamethasone non-suppression was detectable in the 4-month-old group. All in all, some anxiety- and depressive-like symptoms were present in 3xTg-AD mice. Although this strain was not generally more anxious or depressed, some aspects of comorbidity might be studied in selected tests, which may help to develop new possible treatments.


Assuntos
Doença de Alzheimer , Acetilcolinesterase , Doença de Alzheimer/patologia , Animais , Ansiedade/patologia , Dexametasona , Modelos Animais de Doenças , Glucocorticoides , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Sacarose , Proteínas tau
9.
Biomedicines ; 10(4)2022 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-35453610

RESUMO

Estrogen is one of the most important female sex hormones, and is indispensable for reproduction. However, its role is much wider. Among others, due to its neuroprotective effects, estrogen protects the brain against dementia and complications of traumatic injury. Previously, it was used mainly as a therapeutic option for influencing the menstrual cycle and treating menopausal symptoms. Unfortunately, hormone replacement therapy might be associated with detrimental side effects, such as increased risk of stroke and breast cancer, raising concerns about its safety. Thus, tissue-selective and non-classical estrogen analogues have become the focus of interest. Here, we review the current knowledge about estrogen effects in a broader sense, and the possibility of using selective estrogen-receptor modulators (SERMs), selective estrogen-receptor downregulators (SERDs), phytoestrogens, and activators of non-genomic estrogen-like signaling (ANGELS) molecules as treatment.

10.
Int J Mol Sci ; 23(2)2022 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-35054976

RESUMO

Glutamate is the most abundant excitatory amino acid in the central nervous system. Neurons using glutamate as a neurotransmitter can be characterised by vesicular glutamate transporters (VGLUTs). Among the three subtypes, VGLUT3 is unique, co-localising with other "classical" neurotransmitters, such as the inhibitory GABA. Glutamate, manipulated by VGLUT3, can modulate the packaging as well as the release of other neurotransmitters and serve as a retrograde signal through its release from the somata and dendrites. Its contribution to sensory processes (including seeing, hearing, and mechanosensation) is well characterised. However, its involvement in learning and memory can only be assumed based on its prominent hippocampal presence. Although VGLUT3-expressing neurons are detectable in the hippocampus, most of the hippocampal VGLUT3 positivity can be found on nerve terminals, presumably coming from the median raphe. This hippocampal glutamatergic network plays a pivotal role in several important processes (e.g., learning and memory, emotions, epilepsy, cardiovascular regulation). Indirect information from anatomical studies and KO mice strains suggests the contribution of local VGLUT3-positive hippocampal neurons as well as afferentations in these events. However, further studies making use of more specific tools (e.g., Cre-mice, opto- and chemogenetics) are needed to confirm these assumptions.


Assuntos
Ácido Glutâmico/metabolismo , Hipocampo/fisiologia , Células Piramidais/metabolismo , Proteínas Vesiculares de Transporte de Glutamato/genética , Proteínas Vesiculares de Transporte de Glutamato/metabolismo , Animais , Biomarcadores , Fenômenos Eletrofisiológicos , Regulação da Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Camundongos Knockout , Neurotransmissores/metabolismo , Transdução de Sinais , Transmissão Sináptica
11.
Int J Mol Sci ; 22(17)2021 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-34502322

RESUMO

Vasopressin is a ubiquitous molecule playing an important role in a wide range of physiological processes thereby implicated in the pathomechanism of many disorders. Its effect is well characterized through V2 receptors, which regulates the water resorption in kidney, while its vasoconstrictory effect through V1a receptor also received a lot of attention in the maintenance of blood pressure during shock. However, the most striking is its central effect both through the V1b receptors in stress-axis regulation as well as through V1a receptors regulating many aspects of our behavior (e.g., social behavior, learning and memory). Vasopressin has been implicated in the development of depression, due to its connection with chronic stress, as well as schizophrenia because of its involvement in social interactions and memory processes. Epigenetic changes may also play a role in the development of these disorders. The possible mechanism includes DNA methylation, histone modification and/or micro RNAs, and these possible regulations will be in the focus of our present review.


Assuntos
Epigênese Genética , Homeostase , Transtornos Mentais/patologia , Receptores de Vasopressinas/metabolismo , Vasopressinas/metabolismo , Animais , Humanos , Transtornos Mentais/genética , Transtornos Mentais/metabolismo , Receptores de Vasopressinas/genética , Transdução de Sinais , Vasopressinas/genética
12.
PLoS Comput Biol ; 17(9): e1009378, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34529674

RESUMO

Activity-dependent regulation of intrinsic excitability has been shown to greatly contribute to the overall plasticity of neuronal circuits. Such neuroadaptations are commonly investigated in patch clamp experiments using current step stimulation and the resulting input-output functions are analyzed to quantify alterations in intrinsic excitability. However, it is rarely addressed, how such changes translate to the function of neurons when they operate under natural synaptic inputs. Still, it is reasonable to expect that a strong correlation and near proportional relationship exist between static firing responses and those evoked by synaptic drive. We challenge this view by performing a high-yield electrophysiological analysis of cultured mouse hippocampal neurons using both standard protocols and simulated synaptic inputs via dynamic clamp. We find that under these conditions the neurons exhibit vastly different firing responses with surprisingly weak correlation between static and dynamic firing intensities. These contrasting responses are regulated by two intrinsic K-currents mediated by Kv1 and Kir channels, respectively. Pharmacological manipulation of the K-currents produces differential regulation of the firing output of neurons. Static firing responses are greatly increased in stuttering type neurons under blocking their Kv1 channels, while the synaptic responses of the same neurons are less affected. Pharmacological blocking of Kir-channels in delayed firing type neurons, on the other hand, exhibit the opposite effects. Our subsequent computational model simulations confirm the findings in the electrophysiological experiments and also show that adaptive changes in the kinetic properties of such currents can even produce paradoxical regulation of the firing output.


Assuntos
Modelos Neurológicos , Neurônios/fisiologia , Potenciais de Ação/fisiologia , Animais , Células Cultivadas , Biologia Computacional , Simulação por Computador , Sinapses Elétricas/fisiologia , Fenômenos Eletrofisiológicos , Hipocampo/citologia , Hipocampo/fisiologia , Cinética , Camundongos , Técnicas de Patch-Clamp , Canais de Potássio de Abertura Dependente da Tensão da Membrana/fisiologia
13.
Int J Mol Sci ; 22(16)2021 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-34445795

RESUMO

Stress adaptation is of utmost importance for the maintenance of homeostasis and, therefore, of life itself. The prevalence of stress-related disorders is increasing, emphasizing the importance of exploratory research on stress adaptation. Two major regulatory pathways exist: the hypothalamic-pituitary-adrenocortical axis and the sympathetic adrenomedullary axis. They act in unison, ensured by the enormous bidirectional connection between their centers, the paraventricular nucleus of the hypothalamus (PVN), and the brainstem monoaminergic cell groups, respectively. PVN and especially their corticotropin-releasing hormone (CRH) producing neurons are considered to be the centrum of stress regulation. However, the brainstem seems to be equally important. Therefore, we aimed to summarize the present knowledge on the role of classical neurotransmitters of the brainstem (GABA, glutamate as well as serotonin, noradrenaline, adrenaline, and dopamine) in stress adaptation. Neuropeptides, including CRH, might be co-localized in the brainstem nuclei. Here we focused on CRH as its role in stress regulation is well-known and widely accepted and other CRH neurons scattered along the brain may also complement the function of the PVN. Although CRH-positive cells are present on some parts of the brainstem, sometimes even in comparable amounts as in the PVN, not much is known about their contribution to stress adaptation. Based on the role of the Barrington's nucleus in micturition and the inferior olivary complex in the regulation of fine motoric-as the main CRH-containing brainstem areas-we might assume that these areas regulate stress-induced urination and locomotion, respectively. Further studies are necessary for the field.


Assuntos
Adaptação Fisiológica/fisiologia , Tronco Encefálico/metabolismo , Tronco Encefálico/fisiologia , Hormônio Liberador da Corticotropina/metabolismo , Estresse Fisiológico/fisiologia , Animais , Humanos , Neurônios/metabolismo , Neurônios/fisiologia
14.
Front Pharmacol ; 12: 650207, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33935754

RESUMO

Retinal complications of diabetes often lead to deterioration or even loss of vision. This hastens discovery of pharmacological agents able to counterbalance diabetic retinopathy. BGP-15, an emerging small molecule agent, was formerly proven by our workgroup to be retinoprotective on nonobese diabetic animals, Goto-Kakizaki rats. In the present study, we aimed to examine its long-term tolerability or incidental side effects on obese-prone Zucker diabetic fatty (ZDF) rats to further increase the rationale for a future human translation. To make terminal visual status comparable with our other investigations, we also carried out electroretinography (ERG) at the end of the experiment. Our study was started on 16-week-old ZDF rats and lasted for 52 weeks, while BGP was administered daily by gavage. During the 12 months of treatment, 100% of BGP-treated animals survived compared to the non-treated ZDF group, where 60% of the animals died, which was a statistically significant difference. Based on ERG results, BGP-15 was able to counterbalance visual deterioration of ZDF rats caused by long-term diabetes. Some moderate but significant changes were seen in OGTT results and some relationship to oxidative stress by the western blot method: BGP-15 was able to increase expression of HSP70 and decrease that of NFkB in eyes of rats. These were in concert with our previous observations of SIRT1 increment and MMP9 decrement in diabetic eyes by BGP. In summary, not only is BGP-15 not harmful in the long run but it is even able to reduce the related mortality and the serious consequences of diabetes. BGP-15 is an excellent candidate for future drug development against diabetic retinopathy.

15.
Int J Cardiovasc Imaging ; 37(1): 269-273, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32740880

RESUMO

Feeding intolerance and necrotizing enterocolitis (NEC) cause significant morbidity in neonates with duct-dependent systemic circulations. Whether these complications are associated with low blood flow to the bowel is unproven. The aim of this study was to determine whether low descending aortic (DAO) flow is associated with adverse feeding outcomes in neonates with small left-sided structures, including borderline left ventricle and hypoplastic left heart syndrome (HLHS). The cardiac magnetic resonance (CMR) imaging studies and abdominal Doppler ultrasound profiles prior to any cardiac interventions in neonates with small left-sided structures were analyzed. Descending aortic flows, indexed to body surface area, were collected. Medical charts were reviewed for a composite outcome of feeding intolerance and/or NEC. Among the 51 enrolled study patients (mean age 4.6, SD 4.5 days), 13 experienced the composite outcome (feeding intolerance in 13, NEC in 2). The mean DAO flow in patients who experienced the composite outcome was 0.89 L/min/m2 (SD 0.33 L/min/m2), compared to 1.23 L/min/m2 (SD 0.41 L/min/m2) in those that did not (p = 0.007). A DAO flow of 0.91 L/min/m2 identified patients who experienced feeding intolerance or NEC with a sensitivity of 61% and a specificity of 76%. Doppler ultrasound metrics of DAO flow did not correlate with DAO flow or predict adverse feeding outcomes. Low DAO flow is associated with adverse outcomes, including feeding intolerance and NEC, in neonates with small left-sided structures. Heightened clinical vigilance towards feeding complications in patients with low DAO flow is recommended.


Assuntos
Aorta Torácica/fisiopatologia , Ingestão de Alimentos , Nutrição Enteral , Enterocolite Necrosante/etiologia , Síndrome do Coração Esquerdo Hipoplásico/complicações , Aorta Torácica/diagnóstico por imagem , Ecocardiografia Doppler de Pulso , Nutrição Enteral/efeitos adversos , Enterocolite Necrosante/diagnóstico , Enterocolite Necrosante/fisiopatologia , Humanos , Síndrome do Coração Esquerdo Hipoplásico/diagnóstico por imagem , Síndrome do Coração Esquerdo Hipoplásico/fisiopatologia , Recém-Nascido , Imagem Cinética por Ressonância Magnética , Projetos Piloto , Fluxo Sanguíneo Regional , Estudos Retrospectivos , Medição de Risco , Fatores de Risco
16.
Front Microbiol ; 11: 838, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32457720

RESUMO

Eukaryotic species are reproductively isolated by sterility barriers that prevent interspecies fertilization (prezygotic sterility barrier) or the fertilization results in infertile offspring (postzygotic sterility barrier). The Saccharomyces species are isolated by postzygotic sterility barriers. Their allodiploid hybrids form no viable gametes (ascospores) and the viable ascospores of the allotetraploids cannot fertilize (conjugate). Our previous work revealed that this mechanism of reproductive isolation differs from those operating in plants and animals and we designated it double sterility barrier (the failure of homeologous chromosomes to pair and the repression of mating by mating-type heterozygosity). Other studies implicated nucleo-mitochondrial incompatibilities in the sterility of the Saccharomyces hybrids, a mechanism assumed to play a central role in the reproductive isolation of animal species. In this project the mitochondrial genomes of 50 cevarum (S. cerevisiae × S. uvarum) hybrids were analyzed. 62% had S. cerevisiae mitotypes, 4% had S. uvarum mitotypes, and 34% had recombinant mitotypes. All but one hybrid formed viable spores indicating that they had genomes larger than allodiploid. Most of these spores were sterile (no sporulation in the clone of vegetative descendants; a feature characteristic of allodiploids). But regardless of their mitotypes, most hybrids could also form fertile alloaneuploid spore clones at low frequencies upon the loss of the MAT-carrying chromosome of the S. uvarum subgenome during meiosis. Hence, the cevarum alloploid nuclear genome is compatible with both parental mitochondrial genomes as well as with their recombinants, and the sterility of the hybrids is maintained by the double sterility barrier (determined in the nuclear genome) rather than by nucleo-mitochondrial incompatibilities. During allotetraploid sporulation both the nuclear and the mitochondrial genomes of the hybrids could segregate but no correlation was observed between the sterility or the fertility of the spore clones and their mitotypes. Nucleo-mitochondrial incompatibility was manifested as respiration deficiency in certain meiotic segregants. As respiration is required for meiosis-sporulation but not for fertilization (conjugation), these segregants were deficient only in sporulation. Thus, the nucleo-mitochondrial incompatibility affects the sexual processes only indirectly through the inactivation of respiration and causes only partial sterility in certain segregant spore clones.

17.
Int J Mol Sci ; 21(6)2020 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-32204537

RESUMO

High blood glucose and the consequential ischemia-reperfusion (I/R) injury damage vessels of the retina, deteriorating its function, which can be clearly visualized by electroretinography (ERG). The aim of the present study was to evaluate the possible retinoprotective effects of systemic BGP-15, an emerging drug candidate, in an insulin resistant animal model, the Goto-Kakizaki rat, and compare these results with well-known anti-diabetics such as glibenclamide, metformin, and pioglitazone, which even led to some novel conclusions about these well-known agents. Experiments were carried out on diseased animal model (Goto-Kakizaki rats). The used methods include weight measurement, glucose-related measurements-like fasting blood sugar analysis, oral glucose tolerance test, hyperinsulinemic euglycemic glucose clamp (HEGC), and calculations of different indices from HEGC results-electroretinography and Western Blot. Beside its apparent insulin sensitization, BGP-15 was also able to counteract the retina-damaging effect of Type II diabetes comparable to the aforementioned anti-diabetics. The mechanism of retinoprotective action may include sirtuin 1 (SIRT1) and matrix metalloproteinase 9 (MMP9) enzymes, as BGP-15 was able to elevate SIRT1 and decrease MMP9 expression in the eye. Based on our results, this emerging hydroximic acid derivative might be a future target of pharmacological developments as a potential drug against the harmful consequences of diabetes, such as diabetic retinopathy.


Assuntos
Diabetes Mellitus Tipo 2/fisiopatologia , Retinopatia Diabética/prevenção & controle , Hipoglicemiantes/farmacologia , Oximas/farmacologia , Piperidinas/farmacologia , Retina/efeitos dos fármacos , Animais , Glicemia/metabolismo , Diabetes Mellitus Tipo 2/sangue , Modelos Animais de Doenças , Eletrorretinografia , Glibureto/farmacologia , Humanos , Ácidos Hidroxâmicos/química , Ácidos Hidroxâmicos/farmacologia , Insulina/farmacologia , Masculino , Metformina/farmacologia , Estrutura Molecular , Oximas/química , Pioglitazona/farmacologia , Piperidinas/química , Substâncias Protetoras/química , Substâncias Protetoras/farmacologia , Ratos , Ratos Wistar , Retina/fisiopatologia
18.
Int J Mol Sci ; 20(24)2019 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-31842299

RESUMO

The receptorial responsiveness method (RRM) is a procedure that is based on a simple nonlinear regression while using a model with two variables (X, Y) and (at least) one parameter to be determined (cx). The model of RRM describes the co-action of two agonists that consume the same response capacity (due to the use of the same postreceptorial signaling in a biological system). While using RRM, uniquely, an acute increase in the concentration of an agonist (near the receptors) can be quantified (as cx), via evaluating E/c curves that were constructed with the same or another agonist in the same system. As this measurement is sensitive to the implementation of the curve fitting, the goal of the present study was to test RRM by combining different ways and setting options, namely: individual vs. global fitting, ordinary vs. robust fitting, and three weighting options (no weighting vs. weighting by 1/Y2 vs. weighting by 1/SD2). During the testing, RRM was used to estimate the known concentrations of stable synthetic A1 adenosine receptor agonists in isolated, paced guinea pig left atria. The estimates were then compared to the known agonist concentrations (to assess the accuracy of RRM); furthermore, the 95% confidence limits of the best-fit values were also considered (to evaluate the precision of RRM). It was found that, although the global fitting offered the most convenient way to perform RRM, the best estimates were provided by the individual fitting without any weighting, almost irrespective of the fact whether ordinary or robust fitting was chosen.


Assuntos
Dinâmica não Linear , Agonistas do Receptor Purinérgico P1/química , Receptor A1 de Adenosina/química , Adenosina/química , Adenosina/farmacologia , Animais , Relação Dose-Resposta a Droga , Cobaias , Agonistas do Receptor Purinérgico P1/farmacologia
19.
J Clin Med ; 8(11)2019 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-31766212

RESUMO

Salivary IL-6 mRNA was previously identified as a promising biomarker of oral squamous cell carcinoma (OSCC). We performed a multi-center investigation covering all geographic areas of Hungary. Saliva from 95 patients with OSCC and 80 controls, all Caucasian, were collected together with demographic and clinicopathological data. Salivary IL-6 mRNA was quantified by real-time quantitative PCR. Salivary IL-6 protein concentration was measured by enzyme-linked immune-sorbent assay. IL-6 protein expression in tumor samples was investigated by immunohistochemistry. Normalized salivary IL-6 mRNA expression values were significantly higher (p < 0.001) in patients with OSCC (mean ± SE: 3.301 ± 0.885) vs. controls (mean ± SE: 0.037 ± 0.012). Differences remained significant regardless of tumor stage and grade. AUC of the ROC curve was 0.9379 (p < 0.001; 95% confidence interval: 0.8973-0.9795; sensitivity: 0.945; specificity: 0.819). Salivary IL-6 protein levels were significantly higher (p < 0.001) in patients (mean ± SE: 70.98 ± 14.06 pg/mL), than in controls (mean ± SE: 12.45 ± 3.29). Specificity and sensitivity of IL-6 protein were less favorable than that of IL-6 mRNA. Salivary IL-6 mRNA expression was significantly associated with age and dental status. IL-6 manifestation was detected in tumor cells and tumor-infiltrating leukocytes, suggesting the presence of a paracrine loop of stimulation. Salivary IL-6 mRNA is one of the best performing and clinically relevant biomarkers of OSCC.

20.
Molecules ; 24(12)2019 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-31212849

RESUMO

In earlier studies, we generated concentration-response (E/c) curves with CPA (N6-cyclopentyladenosine; a selective A1 adenosine receptor agonist) or adenosine, in the presence or absence of S-(2-hydroxy-5-nitrobenzyl)-6-thioinosine (NBTI, a selective nucleoside transport inhibitor), and with or without a pretreatment with 8-cyclopentyl-N3-[3-(4-(fluorosulfonyl)-benzoyloxy)propyl]-N1-propylxanthine (FSCPX, a chemical known as a selective, irreversible A1 adenosine receptor antagonist), in isolated, paced guinea pig left atria. Meanwhile, we observed a paradoxical phenomenon, i.e. the co-treatment with FSCPX and NBTI appeared to enhance the direct negative inotropic response to adenosine. In the present in silico study, we aimed to reproduce eight of these E/c curves. Four models (and two additional variants of the last model) were constructed, each one representing a set of assumptions, in order to find the model exhibiting the best fit to the ex vivo data, and to gain insight into the paradoxical phenomenon in question. We have obtained in silico evidence for an interference between effects of FSCPX and NBTI upon our ex vivo experimental setting. Regarding the mechanism of this interference, in silico evidence has been gained for the assumption that FSCPX inhibits the effect of NBTI on the level of endogenous (but not exogenous) adenosine. As an explanation, it may be hypothesized that FSCPX inhibits an enzyme participating in the interstitial adenosine formation. In addition, our results suggest that NBTI does not stop the inward adenosine flux in the guinea pig atrium completely.


Assuntos
Antagonistas do Receptor A1 de Adenosina/química , Proteínas de Transporte de Nucleobases/química , Receptor A1 de Adenosina/química , Xantinas/química , Adenosina/química , Adenosina/farmacologia , Antagonistas do Receptor A1 de Adenosina/farmacologia , Animais , Relação Dose-Resposta a Droga , Cobaias , Proteínas de Transporte de Nucleobases/antagonistas & inibidores , Xantinas/farmacologia
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