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Alzheimer's disease (AD) is a neurological ailment that primarily affects the elderly and necessitates an efficient treatment regimen backed up by extensive care. Despite advancement in the in vivo imaging techniques focussing on early diagnosis of reliable biomarkers using novel magnetic resonance imaging (MRI) and positron emission topography (PET) scans, AD remains largely unexplained and effective preventative and treatment strategies are still lacking. Consequently, research groups are constantly attempting to improve its early detection, using both invasive and non-invasive techniques with established core markers like Aß and Tau (t-tau and p-tau) proteins. Unfortunately, African American and other black races are facing an increasing burden of closely associated risk factors, and only a few attempts have been made to find effective complementary and alternative therapies for AD cure and management. A greater epidemiology and natural product research are required to deal with the concurrent rise of dementia among quickly ageing African population, which so far have largely been ignored in addition to a disparity in the AD risk factors. We have tried to bring attention to the issue by reviewing up on this predisposition while generating a perspective on how race may affect AD risk and expression. This article also puts emphasis on finding new research leads from African phytodiversity while presenting several of the important species along with their biological agents found helpful in dementia related symptoms.
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Doença de Alzheimer , Humanos , Idoso , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/tratamento farmacológico , Proteínas tau , Imageamento por Ressonância Magnética , Biomarcadores , Diagnóstico Precoce , Peptídeos beta-Amiloides , Tomografia por Emissão de PósitronsRESUMO
The reaction of alkali metal acetates, M(OAc)·nH2O (M = Li, Na, K), with thermally and hydrolytically unstable di-tert-butylphosphate ((tBuO)2PO2H, dtbp-H) in a 1:1 molar ratio in MeOH at room temperature leads to clean formation of group 1 metal phosphates [Li(µ-dtbp)]n (1), [Na(µ-dtbp)]n (2), and [K4(µ-dtbp)4(µ-H2O)3]n (3). All three compounds are essentially M/L 1:1 complexes. Owing to the presence of larger potassium ions, additional coordinated water molecules are found in 3, which has been further employed as a precursor for the synthesis of a mixed-metal phosphate polymer [CaK(µ-H2O)3(µ-dtbp)3]n (4) by reacting 3 with Ca(OAc)2. Compounds 1-4 have been characterized by various analytical and spectroscopic techniques. Molecular structures of 1-4 have been established in the solid state by single-crystal X-ray diffraction studies, which reveal them to be one-dimensional polymers, where the adjacent metal centers are connected through -O-P-O- bridges formed by the dtbp ligand. These complexes are rare examples of analytically pure alkali metal alkyl phosphates bearing no additional N-donor ligands (other than dtbp ligands, only water molecules are coordinated to the metal centers). Therefore, these compounds can be employed as single-source precursors (SSPs) for nano-sized ceramic phosphates. The thermogravimetric analysis of 1-4 reveals the loss of thermally labile tert-butyl substituents of the organophosphate ligands to form organic-free phosphate materials in the temperature range 300-500 °C. Solvothermal decomposition of 1-3 in boiling toluene leads to the formation of corresponding dihydrogen phosphates M(H2PO4) (M = Li, Na, and K). The thermal decomposition of heterometallic 4 in the temperature range 400-800 °C leads to the formation of phase-pure mixed-metal calcium potassium metaphosphate CaK(PO3)3.
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Compositional interplay of two different cobalt phosphates (Co(H2 PO4 )2 ; Co-DP and Co(PO3 )2 ; Co-MP) loaded on morphologically engineered high surface area nanocarbon leads to an increased electrocatalytic efficiency for oxygen evolution reaction (OER) in near neutral conditions. This is reflected as significant reduction in the onset overpotential (301 mV) and enhanced current density (30 mA cm-2 @ 577 mV). In order to achieve uniform surface loading, organic-soluble thermolabile cobalt-bis(di-tert-butylphosphate) is synthesized in situ inside the nanocarbon matrix and subsequently pyrolyzed at 150 °C to produce Co(H2 PO4 )2 /Co(PO3 )2 (80:20 wt%). Annealing this sample at 200 or 250 °C results in the redistribution of the two phosphate systems to 55:45 or 20:80 (wt%), respectively. Detailed electrochemical measurements clearly establish that the 55:45 (wt%) sample prepared at 200 °C performs the best as a catalyst, owing to a relay mechanism that enhances the kinetics of the 4e- transfer OER process, which is substantiated by micro-Raman spectroscopic studies. It is also unraveled that the engineered nanocarbon support simultaneously enhances the interfacial charge-transfer pathway, resulting in the reduction of onset overpotential, compared to earlier investigated cobalt phosphate systems.
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Thermally and hydrolytically unstable di-tert-butyl phosphate (dtbp-H) has been used as synthon to prepare discrete and polymeric calcium phosphates that are convenient single-source precursors for a range of calcium phosphate ceramic biomaterials. The reactivity of dtbp-H toward two different calcium sources has been found to vary significantly, e.g., the reaction of Ca(OMe)2 with dtbp-H in a 1:6 molar ratio in petroleum ether forms a mononuclear calcium hexa-phosphate complex [Ca(dtbp)2(dtbp-H)4] (1), whereas the change of calcium source to CaH2, in a 1:2 molar ratio under otherwise similar reaction conditions, yields the calcium phosphate polymer, [Ca(µ-dtbp)2(H2O)2·H2O]n(2). Compounds 1 and 2 have been extensively characterized by various spectroscopic and analytical techniques. The solid-state structures of both 1 and 2 have been determined by single-crystal X-ray diffraction studies. In discrete molecule 1, the central calcium ion is surrounded by two anionic dtbp and four neutral dtbp-H ligands in an octahedral coordination environment. Compound 2 is a one-dimensional polymer in which adjacent calcium ions are connected through double dtbp bridges. Solid-state thermolysis of bulk 1 in air leads to the exclusive formation of calcium metaphosphate ß-Ca(PO3)2 in the entire temperature range of 400-800 °C. Thermal decomposition of polymer 2, however, can be fine-tuned to produce either α-Ca(PO3)2 or ß-Ca(PO3)2 depending on the thermolysis conditions employed. Although the sample sintered at 600 °C produces exclusively α-form of Ca(PO3)2, the sample annealed at 800 °C or above produces ß-form. Both α- and ß-forms can also be successively formed one after other by a slow heating of a freshly prepared 2 on the powder diffractometer sample holder. Additional forms of ceramic phosphates have been prepared by solvothermal conditions because of the highly labile nature of the tert-butoxy groups of dtbp in 1 and 2. Solution decomposition of either 1 or 2 in boiling toluene at 140 °C in a sealed tube produces calcium dihydrogen phosphate [Ca(H2PO4)2·H2O] as the only product in the form of single crystals. Solution thermolysis of 2 in protic solvents such as water and methanol can be biased to produce other calcium phosphate biomaterials such as hydroxyapatite [Ca10(PO4)6(OH)2]and calcium monohydrogen phosphate [Ca(HPO4)] in the presence of additional calcium precursors such as CaO and Ca(OMe)2, respectively.
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Manipulation of low-dimensional solids through soft chemical routes is an elegant way to realize newer materials. A new family of single-crystalline transition-metal layered organophosphates, with about 185 000 metal phosphate layers in a single crystal, can be exfoliated to a single-layer nanosheet by a facile and rapid solvent assisted method. This exfoliation aids the formation of high-surface-area pyrophosphates with enhanced supercapacitance.
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The reaction of [Cp*TiCl3] (Cp* = C5Me5) with monoalkyl phosphates (RO)PO3H2 (R = Me, Et, and iPr) in tetrahydrofuran (THF) at 25 °C leads to the formation of binuclear complexes [Cp*2Ti2(µ-O2P(OH)OR)2(µ-O2P(O)OR)2] [R = Me (1), Et (2), and iPr (3)]. On the other hand, the reaction of ( tBuO)2PO2K with [Cp*TiCl3] in acetonitrile or THF results in isolation of either the dinuclear [Cp*2Ti2(µ-O2P(OH)O tBu)2(µ-O2P(O)O tBu)2] (4) or the trinuclear titanophosphate [Cp*3Ti3(µ-O3PO tBu)2(µ-O)2(µ-O2P(O tBu)2)] (5), respectively. The formation of compounds 4 and 5 is facilitated by partial hydrolysis of the tert-butoxy groups of ( tBuO)2PO2K. New titanophosphates 1-5 have been characterized by spectroscopic and analytical methods, and the molecular structures have further been confirmed by single-crystal X-ray diffraction studies. Thermal decomposition studies of 1-5 reveal the initial loss of thermally labile alkyl substituents of the organophosphate ligands, followed by the loss of C5Me5 groups to form an organic-free amorphous titanophosphate in the temperature range 300-500 °C. This material transforms to highly crystalline titanium pyrophosphate TiP2O7 at 800 °C. Compounds 1-5 and the TiP2O7 materials obtained at 300, 500, and 800 °C through the thermal decomposition of 3 have been employed as efficient homogeneous catalysts for the alkene epoxidation reaction. Using hydrogen peroxide as the oxidant in an acetonitrile medium, these catalysts exhibit >90% alkene conversion with >90% epoxide selectivity in 4 h at temperatures below 100 °C.
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Environmental pollution is one of the major problems of these days. One of the reasons of environmental pollution is the indiscriminate use of agrochemicals in agriculture. Fungicides are being extensively used in agriculture for enhancing crop yield and growth by controlling fungal growth. Fungicide carbendazim is widely applied to soil and seeds of vegetable/cereal crops in India and is effective against a very broad spectrum of fungi. The present study was designed to monitor the cyto-genotoxic effects of carbendazim directly in treated soils by cytogenetical analysis using Allium cepa root tip bioassay. In a pot experiment, fungicide carbendazim was added to soil at the rates of 2.5, 5, 7.5, and 10 mg kg-1 soil and uniform size onion bulb was planted in each pot, and three replicates were maintained for each dose at 1, 7, 15, 30, and 45 days after application and roots from onion bulbs were fixed for cytogenetical analysis. Findings indicate that carbendazim treatment leads to a significant dose and duration-dependent decrease in percent mitotic index with related increase in mitotic inhibition. Statistical analysis showed a significant effect of carbendazim doses and duration of treatment on the percentage relative abnormality rate of A. cepa. Phase indices of our study showed high numbers of cells in prophase as compared to other phases at some doses of treatment. The different types of chromosomal abnormalities observed in our study serve as indicators of genotoxicity of carbendazim and we report for the first time the effect of its application directly in soil using a plant test system.
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Allium/efeitos dos fármacos , Benzimidazóis/toxicidade , Carbamatos/toxicidade , Fungicidas Industriais/toxicidade , Allium/fisiologia , Bioensaio , Aberrações Cromossômicas , Produtos Agrícolas , Dano ao DNA , Monitoramento Ambiental , Índia , Meristema , Índice Mitótico , Cebolas/efeitos dos fármacos , Raízes de Plantas/efeitos dos fármacos , Solo , VerdurasRESUMO
Pesticides are a group of chemical substances which are widely used to improve agricultural production. However, these substances could be persistent in soil and water, accumulative in sediment or bio-accumulative in biota depending on their solubility, leading to different types of environmental pollution. The present study was done to assess the impact of pesticides-mancozeb and chlorpyrifos, via morphological and physiological parameters using Allium cepa test system. Phytotoxic effects of pesticides were examined via germination percentage, survival percentage, root and shoot length, root shoot length ratio, seedling vigor index, percentage of phytotoxicity and tolerance index. Oxidative stress on Allium seedlings caused by pesticides was also assessed by investigating the activity of antioxidative enzymes viz. catalase, peroxidase and superoxide dismutase. Correlation was worked out between morphological parameters and antioxidative enzymes to bring out the alliance between them. Mancozeb and chlorpyrifos concentrations were significantly and positively correlated with the activity of antioxidative enzymes and negatively correlated with morphological parameters. Significant positive correlation between various morphological parameters showed their interdependency. However, negative correlation was obtained between activity of antioxidative enzymes and morphological parameters. The enzymes however, showed positive correlation with each other. Based on our result we can conclude that all morphological parameters were adversely affected by the two pesticides as reflected by phytotoxicity in Allium. Their negative correlation with activity of antioxidative enzymes indicates that upregulation of antioxidative enzymes is not sufficient to overcome the toxic effect, thereby signifying the threat being caused by the regular use of these pesticides.
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BACKGROUND: Presenile cataract is commonly idiopathic in origin. However, patients with presenile cataract could have an underlying genetic abnormality of galactose metabolism. We studied the association, if any, between idiopathic presenile cataract and galactose-1 -phosphate uridyl transferase (GALT) gene mutation. METHODS: We selected 50 patients with idiopathic presenile cataract, <45 years of age, and 50 age- and sex-matched controls for the study. Mutations in the GALT gene were determined by polymerase chain reaction restriction fragment length polymorphism. The classical galactosaemia was characterized by Q188R and K285N mutations, whereas Duarte galactosaemia by N314D mutations (Duarte-2: N314D with IVS5-24G >A and Duarte-1: N314D without IVS5- 24G>A). RESULTS: The most common mutation observed was the N314D (Duarte) mutation. The frequencies of classical and N31 4D alleles in patients with presenile cataract (16%) and controls (26%) were not statistically different (p=0.32, OR 0.54, 95% CI 0.20-1.45). Similarly, there was no statistically significant difference in the frequency distribution of Duarte-1 (p=0.77, OR 0.77, 95% CI 0.23-0.24) and Duarte-2 (p=0.44, OR 0.38, 95% CI 0.07-2.03) galactosaemia mutations in patients and controls. CONCLUSION: Duarte galactosaemia, a milder form of the disease, is more common than classical galactosaemia in the Indian population. Duarte galactosaemia is unlikely to be a causative factor in presenile cataract.
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Catarata/genética , Galactosemias/epidemiologia , UTP-Hexose-1-Fosfato Uridililtransferase/genética , Adulto , Fatores Etários , Estudos de Casos e Controles , Catarata/epidemiologia , Catarata/metabolismo , Feminino , Galactose/metabolismo , Galactosemias/genética , Galactosemias/metabolismo , Frequência do Gene , Humanos , Masculino , Polimorfismo de Fragmento de RestriçãoRESUMO
The present investigation was done to assess cytomorphologic parameters as indicators of genotoxicity as it is a simpler method and could be suggested for rapid screening of the vast range of agrochemicals used all over the world. The excessive and indiscriminate use of agrochemicals is responsible for increasing the level of pollutants in the soil environment resulting in cellular and molecular damage to the plants. The cellular damage caused manifestation of the resulting oxidative stress due to pollutants which can go up to the level of DNA. The roots of Allium cepa were treated with 0.5 mg N ml-1 concentration of ammonium nitrate fertilizer for 3, 6, 9 and 12 h, and in mitotic preparation of their respective root, mitotic index, phase indices and the genotoxic markers viz. chromosomal aberrations and binucleate cells were observed and the data statistically analysed. A significant decrease in mitotic index and increase in abnormality percentage as compared to control was observed which increased with the treatment duration. Chromosomal aberrations like stickiness, fragmentation, precocious movement, bridges and disorientations were observed in varying frequencies. A cytomorphologic study revealed that the interphase cell volume of cells of treated roots and their respective interphase nuclear volume were reduced as compared to control. The ratio between nuclear and cytoplasmic volume has been reported to relate to cell integrity. Both these markers viz. cytomorphologic and genotoxic can be used for assessment of the toxicity of agrochemicals including fertilizer; in our study, they have revealed the cytogenotoxic behaviour of ammonium nitrate fertilizer.
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Monitoramento Ambiental , Fertilizantes/toxicidade , Cebolas/efeitos dos fármacos , Aberrações Cromossômicas , Dano ao DNA , Índice Mitótico , Raízes de Plantas/efeitos dos fármacos , Testes de ToxicidadeRESUMO
Aim: To report a case of cytomegalovirus (CMV) neuroretinitis observed in an immunocompetent patient. Materials and methods: The patient presented with a complaint of diminution of vision in both eyes (BE) and had a traumatic cataract in the right eye (RE). Fundus examination of the left eye (LE) revealed an active white, fluffy lesion with an overlying retinal hemorrhage patch with a macular star. The diagnosis of CMV neuroretinitis was established, and the patient commenced treatment with valganciclovir. Results: The patient exhibited no underlying risk factors. Subsequently, a positive response to oral valganciclovir treatment was observed. Discussion: Cytomegalovirus (CMV) neuroretinitis is typically associated with immunocompromised individuals, such as those with HIV/AIDS. The patient's presentation with a traumatic cataract in the right eye and a distinctive fundus appearance in the left eye posed a diagnostic challenge. The absence of common risk factors for CMV infection necessitated a thorough examination and consideration of rare infectious etiologies. The positive response to valganciclovir reinforces its efficacy in managing CMV-related ocular conditions. This case emphasized the necessity for ophthalmologists to maintain a high index of suspicion for CMV and other unusual pathogens when faced with neuroretinitis in patients who do not present with typical systemic immunosuppressive conditions. Early diagnosis and appropriate antiviral therapy prevent potential complications and preserve vision in such atypical presentations. Conclusion: This case underscores the importance of considering rare infectious agents in immunocompetent patients when encountering neuroretinitis, particularly in the absence of typical symptoms or signs of the disease. Abbreviations: CMV = Cytomegalovirus, BE = Both eyes, RE = Right eye, LE = Left eye, CBC = Complete Blood Count, ESR = Erythrocyte Sedimentation Rate, VDRL = Venereal Disease Research Laboratory, FTA-ABS = Fluorescent Treponemal Antibody Absorption, PPD = Purified Protein Derivative, ANA = Anti-Nuclear Antibodies, RF = Rheumatoid Factor, ACE = Anti Converting Enzyme, Ig G = Immunoglobulin G, HSV = Herpes simplex virus.
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Antivirais , Retinite por Citomegalovirus , Citomegalovirus , Imunocompetência , Humanos , Retinite por Citomegalovirus/diagnóstico , Retinite por Citomegalovirus/tratamento farmacológico , Antivirais/uso terapêutico , Citomegalovirus/isolamento & purificação , Masculino , Infecções Oculares Virais/diagnóstico , Infecções Oculares Virais/virologia , Infecções Oculares Virais/tratamento farmacológico , Acuidade Visual , Angiofluoresceinografia/métodos , Valganciclovir/uso terapêutico , Fundo de Olho , Tomografia de Coerência Óptica/métodosRESUMO
Marginal zone (MZ) B cells bridge innate and adaptive immunity by sensing bloodborne antigens and producing rapid antibody and cytokine responses. CD55 is a membrane-bound complement regulator that interferes with complement activation, an important component of innate immunity. CD55 also regulates adaptive immunity-CD55 downregulation is critical for germinal center reactions. MZ B cells also express low CD55, but its role in MZ B cell function is unknown. Using germline knockout mice, we found that similar numbers of MZ B cells are initially established in 3-week-old CD55-deficient mice compared to wild-type (WT) mice. However, MZ B cells fail to accumulate as mice age and undergo increased apoptosis. Following ex vivo stimulation of MZ B cells through Toll-like receptor 9, we observed a proinflammatory phenotype with increased IL-6 expression. These findings demonstrate a critical role for CD55 in supporting MZ B cell survival while also regulating cellular function.
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As the COVID-19 pandemic continues into its third year, emerging data indicates increased risks associated with SARS-CoV-2 infection during pregnancy, including pre-eclampsia, intrauterine growth restriction, preterm birth, stillbirth, and risk of developmental defects in neonates. Here, we review clinical reports to date that address different COVID-19 pregnancy complications. We also document placental pathologies induced by SARS-CoV-2 infection, entry mechanisms in placental cells, and immune responses at the maternal-fetal interface. Since new variants of SARS-CoV-2 are emerging with characteristics of higher transmissibility and more effective immune escape strategies, we also briefly highlight the genomic and proteomic features of SARS-CoV-2 investigated to date. Vector and mRNA-based COVID-19 vaccines continue to be rolled out globally. However, because pregnant individuals were not included in the vaccine clinical trials, some pregnant individuals have safety concerns and are hesitant to take these vaccines. We describe the recent studies that have addressed the effectiveness and safety of the current vaccines during pregnancy. This review also sheds light on important areas that need to be carefully or more fully considered with respect to understanding SARS-CoV-2 disease mechanisms of concern during pregnancy.
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Vacinas contra COVID-19 , COVID-19 , Eficácia de Vacinas , Feminino , Humanos , Gravidez , COVID-19/complicações , COVID-19/prevenção & controle , Pandemias/prevenção & controle , Placenta/patologia , Placenta/virologia , Proteômica , SARS-CoV-2 , Complicações Infecciosas na Gravidez/patologia , Complicações Infecciosas na Gravidez/virologiaRESUMO
STUDY BACKGROUND: In a pluralistic health care delivery model, it is important to assess whether the individual's health care choices are based upon evidences of efficacy and safety. Since the essence of medical pluralism lies in the fact that all such systems are equally accessible to a seeker, in such situation, it is highly relevant to check what defines such choices in real life. OBJECTIVE: To identify the factors influencing the health care choices in a subpopulation seeking Ayurveda health care in an Ayurvedic teaching hospital. MATERIALS AND METHOD: The study was an all-inclusive cross sectional survey, done on randomly selected out patients visiting an Ayurveda teaching hospital. The data was collected using a 21 items questionnaire refined through pilot testing from 7.9.2017 to 30.9.2017. RESULTS: The data of 289 respondents who have given their consent were included in statistical analysis. Out of 21 variables studied for their agreement or disagreement in the study population 8 were found to have a significant proportion in favour of agreement. Among these relative safety (Item 9); disease eradicating potential (Item 14); belief (Item 3) and indirect evidences of efficacy (Item 4) were found to have high significance (p < 0.001). CONCLUSION: Participants chose Ayurveda treatment due to its perceived safety and probability of helping in a particular clinical condition. Contrary to the common perception, enabling factors like availability, accessibility and affordability were given less importance by the participants in making health care choices related to Ayurveda.
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Purpose: To explore straight incision technique in terms of efficacy for intraocular pressure (IOP) lowering by small-incision cataract surgery (SICS) trab versus modified "frown" incision with triangular scleral flap technique. Methods: This study was done at a tertiary health center. It included 44 eyes diagnosed with cataract and coexisting primary glaucoma that underwent SICS with trabeculectomy using modified "frown" incision with triangular scleral flap technique and straight incision in group A (n = 22) and B (n = 22), respectively. Postoperative evaluation was done at first postoperative day, then at the end of first week, third week, and 6 weeks; at the end of third month and finally at the end of sixth months. Data were entered and analyzed via Microsoft Excel sheet and SPSS software using Mann-Whitney U test for averages and Chi-square test for categorical values. Results: Mean preoperative IOP in groups A and B were 38.6 and 29.1 mm Hg respectively, by applanation tonometry. After 6-month follow-up, mean of difference in IOP (preoperative - postoperative) for group A was 20.8 ± 8.3 mm Hg and that for group B was 17.2 ± 13.5 mm Hg. Conclusion: Capacity of IOP reduction of both techniques was found to be comparable and did not show much difference up to the end of 6 months. Mastering technique of group A (modified "frown" incision with triangular scleral flap technique) requires more expertise; the simpler straight incision technique provided in group B may be effectively used by the novice and current era Ophthalmologists to combat glaucoma coexistant with cataract.
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Extração de Catarata , Catarata , Glaucoma , Ferida Cirúrgica , Trabeculectomia , Humanos , Acuidade Visual , Extração de Catarata/métodos , Trabeculectomia/métodos , Pressão Intraocular , Glaucoma/cirurgia , Catarata/complicações , Ferida Cirúrgica/complicações , Ferida Cirúrgica/cirurgia , Resultado do Tratamento , Estudos Retrospectivos , SeguimentosRESUMO
Bruton's tyrosine kinase (Btk) deficiency preferentially eliminates autoreactive B cells while sparing normal humoral responses, but has not been studied in mucosal immunity. Commensal microbes and intact BTK signaling have been independently shown to be essential for arthritis development in K/BxN mice. Here, we examine how BTK-mediated signaling interfaces with the gut microbiome. Btk-deficient K/BxN mice were found to have small Peyer's Patches with reduced germinal center and IgA class-switched B cells. IgA-switched plasma cells in small intestines were reduced, especially in villi of Btk-deficient mice. IgH CDR3 sequencing showed similar V gene diversity and somatic hypermutation frequency despite Btk deficiency but showed reduced CDR3 amino acid polarity, suggesting potential qualitative differences in the gut plasma cell repertoire. Small intestinal IgA was low and IgA coating of commensal bacteria was reduced. IgA-seq showed a shift in small intestinal microbes that are normally IgA-coated into the uncoated fraction in Btk-deficient mice. Overall, this study shows that BTK supports normal intestinal IgA development in response to commensals. This manuscript was previously published as a preprint at: https://www.biorxiv.org/content/10.1101/2021.03.10.434762v2.
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Artrite , Doenças Autoimunes , Microbiota , Tirosina Quinase da Agamaglobulinemia/genética , Animais , Imunidade nas Mucosas , Imunoglobulina A/genética , CamundongosRESUMO
Trophoblast organoids derived from placental villi provide a 3D model system of human placental development, but access to first-trimester tissues is limited. Here, we report that trophoblast stem cells isolated from naive human pluripotent stem cells (hPSCs) can efficiently self-organize into 3D stem-cell-derived trophoblast organoids (SC-TOs) with a villous architecture similar to primary trophoblast organoids. Single-cell transcriptome analysis reveals the presence of distinct cytotrophoblast and syncytiotrophoblast clusters and a small cluster of extravillous trophoblasts, which closely correspond to trophoblast identities in the post-implantation embryo. These organoid cultures display clonal X chromosome inactivation patterns previously described in the human placenta. We further demonstrate that SC-TOs exhibit selective vulnerability to emerging pathogens (SARS-CoV-2 and Zika virus), which correlates with expression levels of their respective entry factors. The generation of trophoblast organoids from naive hPSCs provides an accessible 3D model system of the developing placenta and its susceptibility to emerging pathogens.
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COVID-19 , Células-Tronco Pluripotentes , Infecção por Zika virus , Zika virus , Diferenciação Celular , Feminino , Humanos , Organoides , Placenta/metabolismo , Placentação , Células-Tronco Pluripotentes/metabolismo , Gravidez , SARS-CoV-2 , Trofoblastos/metabolismo , Infecção por Zika virus/metabolismoRESUMO
BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection appears to increase the risk of adverse pregnancy outcomes, such as pre-eclampsia in pregnant women. The mechanism(s) by which this occurs remains unclear. METHODS: We investigated the pathophysiology of SARS-CoV-2 at maternal-fetal interface in pregnant women who tested positive for the virus using RNA in situ hybridization (viral RNA), immunohistochemistry, and hematoxylin and eosin staining. To investigate whether viral infection alters the renin angiotensin system (RAS) in placenta, which controls blood pressure, we treated human trophoblasts with recombinant spike protein or a live modified virus with a vesicular stomatitis viral backbone expressing spike protein (VSV-S). FINDINGS: Viral colonization was highest in maternal decidua, fetal trophoblasts, Hofbauer cells, and in placentas delivered prematurely. We localized SARS-CoV-2 to cells expressing angiotensin-converting enzyme 2 (ACE2) and demonstrate that infected placentas had significantly reduced ACE2. In response to both spike protein and VSV-S, cellular ACE2 decreased although angiotensin II receptor type 1 (AT1R) increased with concomitant increase in soluble fms-like tyrosine kinase-1 (sFlt1). Viral infection decreased pro-angiogenic factors, AT2R, and placental growth factor, which competitively binds to sFlt1. Sera from infected pregnant women had elevated levels of sFlt1 and angiotensin II type 1-receptor autoantibodies prior to delivery, both signatory markers of pre-eclampsia. CONCLUSIONS: SARS-CoV-2 colonizes ACE2-expressing maternal and fetal cells in the placenta. Infection in pregnant women correlates with alteration of placental RAS. As RAS regulates blood pressure, SARS-CoV-2 infection may thus increase adverse hemodynamic outcomes, such as pre-eclampsia in pregnant women. FUNDING: NIH/NICHD grants R01 HD091218 and 3R01HD091218-04S1 (RADx-UP Supplement).
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COVID-19 , Pré-Eclâmpsia , Complicações Infecciosas na Gravidez , Enzima de Conversão de Angiotensina 2 , Feminino , Humanos , Placenta/metabolismo , Fator de Crescimento Placentário/metabolismo , Pré-Eclâmpsia/metabolismo , Gravidez , Complicações Infecciosas na Gravidez/metabolismo , Sistema Renina-Angiotensina , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus/metabolismo , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/metabolismoRESUMO
PROBLEM: The miRNAs show placenta-specific expression patterns, which alter during pregnancy-related complications. In present study, the role of miR-27b-5p during forskolin-mediated BeWo cells fusion has been investigated. METHOD OF STUDY: The fusion of BeWo cells in response to forskolin treatment (25 µM) was studied by desmoplakin I+II staining. Expression profile of miR-27b-5p by qRT-PCR and its targets HSD3ß1 and WNT2B by qRT-PCR and in Western blot were studied. The effect of overexpression of miR-27b-5p and silencing of HSD3ß1 & WNT2B by siRNA on forskolin-mediated BeWo cells fusion and secretion of hCG and progesterone by ELISA was investigated. RESULTS: Time-dependent down-regulation in the expression of miR-27b-5p in forskolin-treated BeWo cells has been confirmed by qRT-PCR. Overexpression of miR-27b-5p significantly inhibits forskolin-mediated BeWo cells fusion as well as hCG & progesterone secretion. HSD3ß1 and WNT2B were identified as targets of miR-27b-5p and are up-regulated in forskolin-treated BeWo cells. Overexpression of miR-27b-5p in BeWo cells downregulates their expression. Further, luciferase reporter assay revealed that miR-27b-5p directly target expression of both HSD3ß1 and WNT2B. Silencing of both HSD3ß1 and WNT2B leads to a significant reduction in forskolin-mediated BeWo cells fusion with concomitant decrease in the secretion of progesterone or/and hCG. Decrease in forskolin-mediated cells fusion observed in miR-27b-5p mimic transfected BeWo cells could be rescued by the overexpression of both HSD3ß1 and WNT2B. CONCLUSION: These observations suggest that reduced miR-27b-5p in forskolin-treated BeWo cells leads to increased secretion of progesterone and hCG due to loss of repressional control on HSD3ß1 and WNT2B.
Assuntos
Glicoproteínas/metabolismo , Complexos Multienzimáticos/metabolismo , Placenta/metabolismo , Progesterona Redutase/metabolismo , Progesterona/biossíntese , Esteroide Isomerases/metabolismo , Proteínas Wnt/metabolismo , Fusão Celular , Linhagem Celular Tumoral , Colforsina/farmacologia , Feminino , Glicoproteínas/genética , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Gravidez , Proteínas Wnt/genéticaRESUMO
Coronavirus disease 2019 or COVID-19 is an emerging viral disease caused by a member of the betacoronavirus family, SARS-CoV-2. Since its' emergence in December 2019, it has rapidly caused close to half a million fatalities globally. Data regarding the impact of COVID-19 on pregnancy are limited. Here, we review pathological findings in placentas from women who tested positive for SARS-CoV-2 as well as information on pregnancy outcomes associated with related and highly pathogenic coronaviruses (ie, severe acute respiratory syndrome (SARS-COV) and the Middle East respiratory syndrome, MERS). We present immune-inflammatory correlates of COVID-19 in pregnancy and review the role of the Renin Angiotensin System in the pathogenesis of COVID-19 in pregnancy. Greater understanding of the pathogenesis of SARS-CoV-2 in the placenta will yield important insight into potential therapeutic interventions for pregnant women with COVID-19.