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1.
J Infect Dis ; 229(1): 161-172, 2024 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-38169301

RESUMO

Human babesiosis is a potentially fatal tick-borne disease caused by intraerythrocytic Babesia parasites. The emergence of resistance to recommended therapies highlights the need for new and more effective treatments. Here we demonstrate that the 8-aminoquinoline antimalarial drug tafenoquine inhibits the growth of different Babesia species in vitro, is highly effective against Babesia microti and Babesia duncani in mice and protects animals from lethal infection caused by atovaquone-sensitive and -resistant B. duncani strains. We further show that a combination of tafenoquine and atovaquone achieves cure with no recrudescence in both models of human babesiosis. Interestingly, elimination of B. duncani infection in animals following drug treatment also confers immunity to subsequent challenge. Altogether, the data demonstrate superior efficacy of tafenoquine plus atovaquone combination over current therapies for the treatment of human babesiosis and highlight its potential in providing protective immunity against Babesia following parasite clearance.


Assuntos
Aminoquinolinas , Babesia , Babesiose , Humanos , Animais , Camundongos , Atovaquona/farmacologia , Atovaquona/uso terapêutico , Modelos Teóricos
2.
J Cardiovasc Dev Dis ; 10(12)2023 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-38132653

RESUMO

BACKGROUND AND MOTIVATION: Coronary artery disease (CAD) has the highest mortality rate; therefore, its diagnosis is vital. Intravascular ultrasound (IVUS) is a high-resolution imaging solution that can image coronary arteries, but the diagnosis software via wall segmentation and quantification has been evolving. In this study, a deep learning (DL) paradigm was explored along with its bias. METHODS: Using a PRISMA model, 145 best UNet-based and non-UNet-based methods for wall segmentation were selected and analyzed for their characteristics and scientific and clinical validation. This study computed the coronary wall thickness by estimating the inner and outer borders of the coronary artery IVUS cross-sectional scans. Further, the review explored the bias in the DL system for the first time when it comes to wall segmentation in IVUS scans. Three bias methods, namely (i) ranking, (ii) radial, and (iii) regional area, were applied and compared using a Venn diagram. Finally, the study presented explainable AI (XAI) paradigms in the DL framework. FINDINGS AND CONCLUSIONS: UNet provides a powerful paradigm for the segmentation of coronary walls in IVUS scans due to its ability to extract automated features at different scales in encoders, reconstruct the segmented image using decoders, and embed the variants in skip connections. Most of the research was hampered by a lack of motivation for XAI and pruned AI (PAI) models. None of the UNet models met the criteria for bias-free design. For clinical assessment and settings, it is necessary to move from a paper-to-practice approach.

3.
Chem Biodivers ; : e202301129, 2023 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-37728015

RESUMO

This work described a comprehensive study to estimate chemical constituents of essential oils (EOs) extracted from different parts of the Callistemon citrinus viz: fruits, leaves and aerial part. The EOs were characterized using physicochemical parameters, and GC-FID/MS. It was observed that among different parts, aerial part has the highest oil yield (0.90 %) followed by leaves and fruits. Further, seventeen compounds were characterized, and represented total amount (97.2-99.5 %) with domination of monoterpenes (12.5-34.6 %) and oxygenated monoterpenes hydrocarbon (61.8-86.8 %). α-pinene (11.8-24.7 %), α-phellandrene (1.2-3.0 %), p-cymene (3.3-3.9 %) and 1,8-cineole (58.3-85.1 %) were found as major compounds in C. citrinus samples. These major compounds are the quality chemical markers of C. citrinus oil. The findings revealed significant quantitative variations in EO composition of samples and were also clearly supported by multivariate statistical analysis. Moreover, EOs were evaluated for glucosidase and colon cancer cell lines inhibitory activities, which were found promising.

4.
Neurotoxicology ; 94: 46-58, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36336097

RESUMO

A mobile phone is now a commonly used device for digital media and communication among all age groups. Young adolescents use it for longer durations, which exposes them to radiofrequency electromagnetic radiation (RF-EMR). This exposure can lead to neuropsychiatric changes. The underlying cellular mechanism behind these changes requires detailed investigation. In the present study, we investigated the effect of RF-EMR emitted from mobile phones on young adolescent rat brains. Wistar rats (5 weeks, male) were exposed to RF-EMR signal (2115 MHz) at a head average specific absorption rate (SAR) of 1.51 W/kg continuously for 8 h. Higher level of lipid peroxidation, carbon-centered lipid radicals, and single-strand DNA damage was observed in the brain of rat exposed to RF-EMR. The number of BrdU-positive cells in the dentate gyrus (DG) decreased in RF-EMR-exposed rats, indicating reduced neurogenesis. RF-EMR exposure also induced degenerative changes and neuronal loss in DG neurons but had no effect on the CA3 and CA1 neurons of the hippocampus and cerebral cortex. The activity of Pro-caspase3 did not increase upon exposure in any of the brain regions, pointing out that degeneration observed in the DG region is not dependent on caspase activation. Results indicate that short-term acute exposure to RF-EMR induced the generation of carbon-centered lipid radicals and nuclear DNA damage, both of which likely played a role in the impaired neurogenesis and neuronal degeneration seen in the young brain's hippocampus region. The understanding of RF-EMR-induced alteration in the brain at the cellular level will help develop appropriate interventions for reducing its adverse impact.


Assuntos
Campos Eletromagnéticos , Internet , Ratos , Masculino , Animais , Ratos Wistar , Campos Eletromagnéticos/efeitos adversos , Radiação Eletromagnética , Neurônios , Encéfalo/efeitos da radiação , Dano ao DNA , Lipídeos
5.
Front Cell Infect Microbiol ; 12: 1039197, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36506011

RESUMO

The significant rise in the number of tick-borne diseases represents a major threat to public health worldwide. One such emerging disease is human babesiosis, which is caused by several protozoan parasites of the Babesia genus of which B. microti is responsible for most clinical cases reported to date. Recent studies have shown that during its intraerythrocytic life cycle, B. microti exports several antigens into the mammalian host using a novel vesicular-mediated secretion mechanism. One of these secreted proteins is the immunodominant antigen BmGPI12, which has been demonstrated to be a reliable biomarker of active B. microti infection. The major immunogenic determinants of this antigen remain unknown. Here we provide a comprehensive molecular and serological characterization of a set of eighteen monoclonal antibodies developed against BmGPI12 and a detailed profile of their binding specificity and suitability in the detection of active B. microti infection. Serological profiling and competition assays using synthetic peptides identified five unique epitopes on the surface of BmGPI12 which are recognized by a set of eight monoclonal antibodies. ELISA-based antigen detection assays identified five antibody combinations that specifically detect the secreted form of BmGPI12 in plasma samples from B. microti-infected mice and humans but not from other Babesia species or P. falciparum.


Assuntos
Babesia microti , Babesia , Gastrópodes , Malária Falciparum , Humanos , Animais , Camundongos , Epitopos , Anticorpos Monoclonais , Epitopos Imunodominantes , Mamíferos
6.
Anesth Pain Med (Seoul) ; 17(3): 271-279, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35918859

RESUMO

BACKGROUND: During functional endoscopic sinus surgery (FESS), intranasal bleeding affects operative field visibility and increases the frequency of complications. Therefore, hypotensive anesthesia is a widely used technique to improve surgical outcomes. This study aimed to compare the efficacy of propofol and dexmedetomidine infusion for hypotensive anesthesia in patients undergoing FESS. METHODS: This prospective randomized trial was conducted in 80 adult patients who were scheduled for FESS under general anesthesia. Patients were randomly divided into two groups: group P (n = 40) received propofol infusion of 100-200 µg/kg/min and group D (n = 40) received dexmedetomidine infusion with a loading dose of 1 µg/kg over 10 min after induction, followed by maintenance infusion of 0.4-0.8 µg/kg/h. Intraoperative blood loss, quality of the surgical field (Fromme- Boezaart scale), hemodynamic control, and patient recovery were recorded. Statistical analysis was performed using Student's t-test, chi-square test, and Mann-Whitney U test. RESULTS: The mean arterial pressure and heart rate were significantly lower in group D throughout the surgery than in group P. Blood loss was significantly higher in group P (100.73 ± 18.12 ml) than in group D (85.70 ± 18.56 ml). The average number of patients with Fromme's score 1/2/3 was comparable between the groups. Intraoperatively, only one incidence of bradycardia and hypotension was observed in group D (2.5%) compared to group P. CONCLUSIONS: Both dexmedetomidine and propofol are efficacious and safe drugs for facilitating controlled hypotension during FESS; however, dexmedetomidine provides better hemodynamic control and is associated with lesser blood loss without any significant adverse effects.

7.
NAR Cancer ; 4(2): zcac015, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35528200

RESUMO

Musashi 2 (MSI2) is an RNA binding protein (RBP) that regulates asymmetric cell division and cell fate decisions in normal and cancer stem cells. MSI2 appears to repress translation by binding to 3' untranslated regions (3'UTRs) of mRNA, but the identity of functional targets remains unknown. Here, we used individual nucleotide resolution cross-linking and immunoprecipitation (iCLIP) to identify direct RNA binding partners of MSI2 and integrated these data with polysome profiling to obtain insights into MSI2 function. iCLIP revealed specific MSI2 binding to thousands of mRNAs largely in 3'UTRs, but translational differences were restricted to a small fraction of these transcripts, indicating that MSI2 regulation is not triggered by simple binding. Instead, the functional targets identified here were bound at higher density and contain more 'UAG' motifs compared to targets bound nonproductively. To further distinguish direct and indirect targets, MSI2 was acutely depleted. Surprisingly, only 50 transcripts were found to undergo translational induction on acute loss. Using complementary approaches, we determined eukaryotic translation initiation factor 3A (EIF3A) to be an immediate, direct target. We propose that MSI2 downregulation of EIF3A amplifies these effects on translation. Our results also underscore the challenges in defining functional targets of RBPs since mere binding does not imply a discernible functional interaction.

8.
Emerg Microbes Infect ; 11(1): 938-955, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35264080

RESUMO

The family of apicomplexan specific proteins contains caspases-like proteins called "metacaspases". These enzymes are present in the malaria parasite but absent in human; therefore, these can be explored as potential drug targets. We deleted the MCA-2 gene from Plasmodium berghei genome using a gene knockout strategy to decipher its precise function. This study has identified that MCA-2 plays an important role in parasite transmission since it is critical for the formation of gametocytes and for maintaining an appropriate number of infectious sporozoites required for sporogony. It is noticeable that a significant reduction in gametocyte, oocysts, ookinete and sporozoites load along with a delay in hepatocytes invasion were observed in the MCA-2 knockout parasite. Furthermore, a study found the two MCA-2 inhibitory molecules known as C-532 and C-533, which remarkably inhibited the MCA-2 activity, abolished the in vitro parasite growth, and also impaired the transmission cycle of P. falciparum and P. berghei in An. stephensi. Our findings indicate that the deletion of MCA-2 hampers the Plasmodium development during erythrocytic and exo-erythrocytic stages, and its inhibition by C-532 and C-533 critically affects the malaria transmission biology.


Assuntos
Malária , Proteínas de Protozoários , Animais , Gametogênese , Humanos , Malária/parasitologia , Plasmodium berghei/genética , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo , Esporozoítos/metabolismo
9.
J Allergy Clin Immunol ; 149(6): 2053-2061.e6, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35240143

RESUMO

BACKGROUND: Thymic stromal lymphopoietin (TSLP) promotes TH2 inflammation and is deeply intertwined with inflammatory dermatoses like atopic dermatitis. The mechanisms regulating TSLP are poorly defined. OBJECTIVE: We investigated whether and by what mechanisms mast cells (MCs) foster TSLP responses in the cutaneous environment. METHODS: Ex vivo and in vivo skin MC degranulation was induced by compound 48/80 in wild-type protease-activated receptor 2 (PAR-2)- and MC-deficient mice in the presence or absence of neutralizing antibodies, antagonists, or exogenous mouse MC protease 6 (mMCP6). Primary human keratinocytes and murine skin explants were stimulated with lysates/supernatants of human skin MCs, purified tryptase, or MC lysate diminished of tryptase. Chymase and histamine were also used. TSLP was quantified by ELISA, real-time quantitative PCR, and immunofluorescence staining. RESULTS: Mas-related G protein-coupled receptor X2 (Mrgprb2) activation elicited TSLP in intact skin, mainly in the epidermis. Responses were strictly MC dependent and relied on PAR-2. Complementarily, TSLP was elicited by tryptase in murine skin explants. Exogenous mMCP6 could fully restore responsiveness in MC-deficient murine skin explants. Conversely, PAR-2 knockout mice were unresponsive to mMCP6 while displaying increased responsiveness to other inflammatory pathways, such as IL-1α. Indeed, IL-1α acted in concert with tryptase. In primary human keratinocytes, MC-elicited TSLP generation was likewise abolished by tryptase inhibition or elimination. Chymase and histamine did not affect TSLP production, but histamine triggered IL-6, IL-8, and stem cell factor. CONCLUSION: MCs communicate with kerationocytes more broadly than hitherto suspected. The tryptase/PAR-2 axis is a crucial component of this cross talk, underlying MC-dependent stimulation of TSLP in neighboring kerationocytes. Interference specifically with MC tryptase may offer a treatment option for disorders initiated or perpetuated by aberrant TSLP, such as atopic dermatitis.


Assuntos
Dermatite Atópica , Receptor PAR-2 , Animais , Quimases/metabolismo , Citocinas/metabolismo , Histamina/metabolismo , Humanos , Queratinócitos/metabolismo , Mastócitos/metabolismo , Camundongos , Receptor PAR-2/genética , Receptor PAR-2/metabolismo , Triptases/metabolismo , Linfopoietina do Estroma do Timo
10.
Environ Toxicol ; 37(4): 836-847, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34984797

RESUMO

Worldwide, the number of mobile phone users has increased from 5.57 billion in 2011 to 6.8 billion in 2019. However, short- and long-term impact of the electromagnetic radiation emitting from mobile phones on tissue homeostasis with particular to brain proteome composition needs further investigation. In this study, we attempted a global proteome profiling study of rat hippocampus exposed to mobile phone radiation for 20 weeks (for 3 h/day for 5 days/week) to identify deregulated proteins and western blot analysis for validation. As a result, we identified 358 hippocampus proteins, of which 16 showed deregulation (log2 (exposed/sham) ≥ ±1.0, p-value <.05). Majority of these deregulated proteins grouped into three clusters sharing similar molecular pathways. A set of four proteins (Succinate-semialdehyde dehydrogenase: Aldh5a1, Na+ K+ transporting ATPase: Atp1b2, plasma membrane calcium transporting ATPase: PMCA and protein S100B) presenting each functional pathway were selected for validation. Western blot analysis of these proteins, in an independent sample set, corroborated the mass spectrometry findings. Aldh5a1 involve in cellular energy metabolism, both Atp1b2 and PMCA responsible for membrane transport and protein S100B have a neuroprotective role. In conclusion, we present a deregulated hippocampus proteome upon mobile phone radiation exposure, which might influence the healthy functioning of the brain.


Assuntos
Telefone Celular , Campos Eletromagnéticos , Animais , Campos Eletromagnéticos/efeitos adversos , Radiação Eletromagnética , Hipocampo , Proteoma , Ratos
11.
Bio Protoc ; 12(22)2022 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-36620533

RESUMO

Babesiosis is a tick-borne disease caused by pathogens belonging to the genus Babesia. In humans, the disease presents as a malaria-like illness and can be fatal in immunocompromised and elderly people. In the past few years, human babesiosis has been a rising concern worldwide. The disease is transmitted through tick bite, blood transfusion, and transplacentally in rare cases, with several species of Babesia causing human infection. Babesia microti, Babesia duncani, and Babesia divergens are of particular interest because of their important health impact and amenability to research inquiries. B. microti, the most commonly reported Babesia pathogen infecting humans, can be propagated in immunocompetent and immunocompromised mice but so far has not been successfully continuously propagated in vitro in human red blood cells (hRBCs). Conversely, B. divergens can be propagated in vitro in human red blood cells but lacks a mouse model to study its virulence. Recent studies have highlighted the uniqueness of B. duncani as an ideal model organism to study intraerythrocytic parasitism in vitro and in vivo. An optimized B. duncani in culture and in mouse (ICIM) model has recently been described, combining long-term continuous in vitro culture of the parasite in hRBCs with an animal model of parasitemia (P) and lethal infection in C3H/HeJ mice. Here, we provide a detailed protocol for the use of the B. duncani ICIM model in research. This model provides a unique and sound foundation to gain further insights into the biology, pathogenesis, and virulence of Babesia and other intraerythrocytic parasites, and has been validated as an efficient system to evaluate novel strategies for the treatment of human babesiosis and possibly other parasitic diseases. This protocol was validated in: J Infect Dis (2022), DOI: 10.1093/infdis/jiac181 Graphical abstract ICIM model [Adapted and modified from Pal et al. (2022)].

12.
BMC Biol ; 19(1): 261, 2021 12 11.
Artigo em Inglês | MEDLINE | ID: mdl-34895221

RESUMO

BACKGROUND: Inositol pyrophosphates (PP-InsPs) are high-energy derivatives of inositol, involved in different signalling and regulatory responses of eukaryotic cells. Distinct PP-InsPs species are characterized by the presence of phosphate at a variable number of the 6-carbon inositol ring backbone, and two distinct classes of inositol phosphate kinases responsible for their synthesis have been identified in Arabidopsis, namely ITPKinase (inositol 1,3,4 trisphosphate 5/6 kinase) and PP-IP5Kinase (diphosphoinositol pentakisphosphate kinases). Plant PP-IP5Ks are capable of synthesizing InsP8 and were previously shown to control defense against pathogens and phosphate response signals. However, other potential roles of plant PP-IP5Ks, especially towards abiotic stress, remain poorly understood. RESULTS: Here, we characterized the physiological functions of two Triticum aestivum L. (hexaploid wheat) PPIP5K homologs, TaVIH1 and TaVIH2. We demonstrate that wheat VIH proteins can utilize InsP7 as the substrate to produce InsP8, a process that requires the functional VIH-kinase domains. At the transcriptional level, both TaVIH1 and TaVIH2 are expressed in different wheat tissues, including developing grains, but show selective response to abiotic stresses during drought-mimic experiments. Ectopic overexpression of TaVIH2-3B in Arabidopsis confers tolerance to drought stress and rescues the sensitivity of Atvih2 mutants. RNAseq analysis of TaVIH2-3B-expressing transgenic lines of Arabidopsis shows genome-wide reprogramming with remarkable effects on genes involved in cell-wall biosynthesis, which is supported by the observation of enhanced accumulation of polysaccharides (arabinogalactan, cellulose, and arabinoxylan) in the transgenic plants. CONCLUSIONS: Overall, this work identifies a novel function of VIH proteins, implicating them in modulation of the expression of cell-wall homeostasis genes, and tolerance to water-deficit stress. This work suggests that plant VIH enzymes may be linked to drought tolerance and opens up the possibility of future research into using plant VIH-derived products to generate drought-resistant plants.


Assuntos
Arabidopsis , Arabidopsis/metabolismo , Difosfatos/metabolismo , Secas , Regulação da Expressão Gênica de Plantas , Fosfatos de Inositol/metabolismo , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Estresse Fisiológico , Triticum/genética
13.
Fish Shellfish Immunol ; 115: 124-133, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34077788

RESUMO

Aquaculture is one of the important globally growing industries. It serves as an important food source of protein for human beings. With the expanding demand for the fish and their products it has become extremely important to improve the aquaculture practices. Aquaculture in India has witnessed huge mortalities caused by bacteria, viruses, fungi, nematodes etc. Aquatic weeds plants are harmful for aquaculture in many ways. Present study is aimed to overcome the disease caused by Aeromonas hydrophila (fish pathogenic bacteria) through feed supplementation of two aquatic weed plants (Azolla pinnata and Ceratophyllum demersum). The fish were divided into 6 groups: experimental groups (fish fed on supplementary feed at 5% and 2.5% concentration for individual plant and challenged with bacteria), positive control (fish fed on non-supplemented feed and challenged with bacteria) and negative control (fish fed on non-supplementary feed and not challenged with bacteria). It was observed that supplemented feed enhanced both cell mediated and humoral immunity in fish. Therefore, we advocate that feed formulated with incorporation of Azolla pinnata and Ceratophyllum demersum leaf powder at 5% and 2.5% could be used to prevent disease caused by A. hydrophila or can be used to enhance fish health by boosting its immune system. The results of this study also showed an improved digestibility in fish fed on supplemented feed.


Assuntos
Imunidade Adaptativa/efeitos dos fármacos , Peixes-Gato/fisiologia , Sistema Digestório/efeitos dos fármacos , Gleiquênias/química , Imunidade Inata/efeitos dos fármacos , Fatores Imunológicos/metabolismo , Magnoliopsida/química , Ração Animal/análise , Animais , Peixes-Gato/imunologia , Dieta/veterinária , Suplementos Nutricionais/análise , Relação Dose-Resposta a Droga , Fatores Imunológicos/administração & dosagem , Masculino , Polypodiaceae
14.
BMC Pulm Med ; 20(1): 302, 2020 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-33198714

RESUMO

BACKGROUND: The increasing trend of Chronic Obstructive Pulmonary Disease (COPD) in becoming the third leading cause of deaths by 2020 is of great concern, globally as well as in India. Dysregulation of protease/anti-protease balance in COPD has been reported to cause tissue destruction, inflammation and airway remodelling; which are peculiar characteristics of COPD. Therefore, it is imperative to explore various serum proteases involved in COPD pathogenesis, as candidate biomarkers. COPD and Asthma often have overlapping symptoms and therefore involvement of certain proteases in their pathogenesis would render accurate diagnosis of COPD to be difficult. METHODS: Serum samples from controls, COPD and Asthma patients were collected after requisite institutional ethics committee approvals. The preliminary analysis qualitatively and quantitatively analyzed various serum proteases by ELISA and mass spectrometry techniques. In order to identify a distinct biomarker of COPD, serum neutrophil elastase (NE) and matrix metalloprotease-2 (MMP-2) from COPD and Asthma patients were compared; as these proteases tend to have overlapping activities in both the diseases. A quantitative analysis of the reactive oxygen species (ROS) in the serum of controls and COPD patients was also performed. Statistical analysis for estimation of p-values was performed using unpaired t-test with 95% confidence interval. RESULTS: Amongst the significantly elevated proteases in COPD patients vs the controls- neutrophil elastase (NE) [P < 0.0241], caspase-7 [P < 0.0001] and matrix metalloprotease-2 (MMP-2) [P < 0.0001] were observed, along with increased levels of reactive oxygen species (ROS) [P < 0.0001]. The serum dipeptidyl peptidase-IV (DPP-IV) [P < 0.0010) concentration was found to be decreased in COPD patients as compared to controls. Interestingly, a distinct elevation of MMP-2 was observed only in COPD patients, but not in Asthma, as compared to controls. Mass spectrometry analysis further identified significant alterations (fold-change) in various proteases (carboxy peptidase, MMP-2 and human leukocyte elastase), anti-proteases (Preg. zone protein, α-2 macroglobulin, peptidase inhibitor) and signalling mediators (cytokine suppressor- SOCS-3). CONCLUSION: The preliminary study of various serum proteases in stable COPD patients distinctly identified elevated MMP-2 as a candidate biomarker for COPD, subject to its validation in large cohort studies.


Assuntos
Elastase de Leucócito/sangue , Metaloproteinase 2 da Matriz/sangue , Doença Pulmonar Obstrutiva Crônica/sangue , Espécies Reativas de Oxigênio/sangue , Biomarcadores/sangue , Humanos , Índia , Doença Pulmonar Obstrutiva Crônica/patologia , Índice de Gravidade de Doença
15.
J Bacteriol ; 202(21)2020 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-32817092

RESUMO

Cell growth and division are coordinated, ensuring homeostasis under any given growth condition, with division occurring as cell mass doubles. The signals and controlling circuit(s) between growth and division are not well understood; however, it is known in Escherichia coli that the essential GTPase Era, which is growth rate regulated, coordinates the two functions and may be a checkpoint regulator of both. We have isolated a mutant of Era that separates its effect on growth and division. When overproduced, the mutant protein Era647 is dominant to wild-type Era and blocks division, causing cells to filament. Multicopy suppressors that prevent the filamentation phenotype of Era647 either increase the expression of FtsZ or decrease the expression of the Era647 protein. Excess Era647 induces complete delocalization of Z rings, providing an explanation for why Era647 induces filamentation, but this effect is probably not due to direct interaction between Era647 and FtsZ. The hypermorphic ftsZ* allele at the native locus can suppress the effects of Era647 overproduction, indicating that extra FtsZ is not required for the suppression, but another hypermorphic allele that accelerates cell division through periplasmic signaling, ftsL*, cannot. Together, these results suggest that Era647 blocks cell division by destabilizing the Z ring.IMPORTANCE All cells need to coordinate their growth and division, and small GTPases that are conserved throughout life play a key role in this regulation. One of these, Era, provides an essential function in the assembly of the 30S ribosomal subunit in Escherichia coli, but its role in regulating E. coli cell division is much less well understood. Here, we characterize a novel dominant negative mutant of Era (Era647) that uncouples these two activities when overproduced; it inhibits cell division by disrupting assembly of the Z ring, without significantly affecting ribosome production. The unique properties of this mutant should help to elucidate how Era regulates cell division and coordinates this process with ribosome biogenesis.


Assuntos
Pontos de Checagem do Ciclo Celular , Divisão Celular , Proteínas de Escherichia coli/metabolismo , Escherichia coli/citologia , Proteínas de Ligação ao GTP/metabolismo , Proteínas de Ligação a RNA/metabolismo , Proteínas de Bactérias/metabolismo , Proteínas de Ciclo Celular/metabolismo , Proteínas do Citoesqueleto/metabolismo , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Ligação ao GTP/genética , Proteínas Mutantes/metabolismo , Proteínas de Ligação a RNA/genética
16.
Environ Sci Pollut Res Int ; 27(16): 19340-19351, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32212071

RESUMO

In the present lifestyle, we are continuously exposed to radiofrequency electromagnetic field (RF-EMF) radiation generated mainly by mobile phones (MP). Among other organs, our brain and hippocampus in specific, is the region where effect of any environmental perturbation is most pronounced. So, this study was aimed to examine changes in major parameters (oxidative stress, level of pro-inflammatory cytokines (PICs), hypothalamic-pituitary-adrenal (HPA) axis hormones, and contextual fear conditioning) which are linked to hippocampus directly or indirectly, upon exposure to mobile phone radiofrequency electromagnetic field (MP-RF-EMF) radiation. Exposure was performed on young adult male Wistar rats for 16 weeks continuously (2 h/day) with MP-RF-EMF radiation having frequency, power density, and specific absorption rate (SAR) of 1966.1 MHz, 4.0 mW/cm2, and 0.36 W/kg, respectively. Another set of animals kept in similar conditions without any radiation exposure serves as control. Towards the end of exposure period, animals were tested for fear memory and then euthanized to measure hippocampal oxidative stress, level of circulatory PICs, and stress hormones. We observed significant increase in hippocampal oxidative stress (p < 0.05) and elevated level of circulatory PICs viz. IL-1beta (p < 0.01), IL-6 (p < 0.05), and TNF-alpha (p < 0.001) in experimental animals upon exposure to MP-RF-EMF radiation. Adrenal gland weight (p < 0.001) and level of stress hormones viz. adrenocorticotropic hormone (ACTH) (p < 0.01) and corticosterone (CORT) (p < 0.05) were also found to increase significantly in MP-RF-EMF radiation-exposed animals as compared with control. However, alteration in contextual fear memory was not significant enough. In conclusion, current study shows that chronic exposure to MP-RF-EMF radiation emitted from mobile phones may induce oxidative stress, inflammatory response, and HPA axis deregulation. However, changes in hippocampal functionality depend on the complex interplay of several opposing factors that got affected upon MP-RF-EMF exposure.


Assuntos
Telefone Celular , Sistema Hipotálamo-Hipofisário , Animais , Campos Eletromagnéticos , Medo , Humanos , Masculino , Estresse Oxidativo , Sistema Hipófise-Suprarrenal , Ondas de Rádio , Ratos , Ratos Wistar , Adulto Jovem
17.
3 Biotech ; 9(7): 279, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31245243

RESUMO

Blood and the linings of blood vessels may be regarded as a fifth tissue type. The human body contains 5 × 109 red blood cells (RBCs) per ml, a total of 2.5 × 1013 cells in the 5 l of blood present in the body. With an average lifetime of 125 days, human RBCs are destroyed by leukocytes in the spleen and liver. Nowadays red blood cells are extensively used to study various metabolic functions. Nanoparticles (NP) are being widely accepted for drug delivery system. This review summarizes the red blood cells, NPs and their characteristics on the basis of the RBC components along with drug delivery systems through RBCs. Further, we also discussed that how erythrocytes can be used as an efficient in vitro model for evaluating the efficacy of various nanocomposite materials.

18.
BMC Complement Altern Med ; 19(1): 119, 2019 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-31170971

RESUMO

BACKGROUND: Staphylococcus aureus is a notorious pathogen which often causes nosocomial and community attained infections. These infections steadily increased after evolving the resistance due to indecorous practice of antibiotics and now become a serious health issue. Ouabain is a Na+/K+-ATPase inhibitor that leads to increase the heart contraction in patients with congestive heart failure. METHODS: In the present study, in vitro antimicrobial effect of ouabain together with aminoglycosides was determined against clinical and non-clinical S. aureus strains. Using checkerboard, Gentamycin uptake and biofilm assays, we analysed he interactions of ouabain with aminoglycosides. RESULTS: Ouabain induced the staphylocidal potency of aminoglycosides by remarkably reducing the MIC of gentamycin (GEN) by 16 (0.25 µg/mL), 8 folds (0.5 µg/mL) amikacin (AMK); and 16 folds (1.0 µg/mL) with kanamycin (KAN), compared to their individual doses. OBN severely reduced cell viability within 60 min with GEN (1 µg/mL), KAN (2 µg/mL) and 90 min with AMK (1 µg/mL). This bactericidal effect was enhanced due to GEN uptake potentiated by 66% which led to increase the cell permeability as revealed by leakage of bacterial ATP and nitrocefin assay. The biofilm adherence disrupted by 80 and 50% at 5 mg/mL and 1.5 mg/mL OBN and 50 and 90% biofilm formation was inhibited at 5 mg/mL (MBIC50) and 10 mg/mL (MBIC90), respectively. Moreover, OBN with GEN further induced biofilm inhibition by 67 ± 5% at pH 7.0. CONCLUSIONS: Taken together, we established that OBN synergizes the antimicrobial activity of aminoglycosides that induces cell killing due to intracellular accumulation of GEN by disturbing cell homeostasis. It may be proven an effective approach for the treatment of staphylococcal infections.


Assuntos
Aminoglicosídeos/farmacologia , Antibacterianos/farmacologia , Ouabaína/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Sinergismo Farmacológico , Testes de Sensibilidade Microbiana
19.
Andrologia ; 51(3): e13201, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30461041

RESUMO

In recent years, there has been significant increase in mobile phone users. With this, health concerns associated with the exposure to electromagnetic radiation are also increasing. Continuous exposure to electromagnetic (EM) radiation generated from mobile phone is one of the probable reasons behind increasing male infertility. EM radiations induce oxidative stress that leads to numerous changes in reproductive parameters. With this hypothesis, we studied the effect of 3G mobile phone radiations on the reproductive system of male Wistar rats. Adult rats were divided into two groups: control and radio frequency-exposed. The animals were exposed to 3G mobile phone radiation for 45 days (2 hr/day) in specially designed exposure setup under standard conditions. Various biochemical and physiological parameters such as sperm count, sperm morphology, mitochondrial activity, lipid peroxidation, reactive oxygen species level and histopathological analysis were studied. Histopathological examination revealed a reduction in spermatogenic cells and alterations in sperm membrane. Significant increase in ROS and lipid peroxidation level with simultaneously decrease in sperm count, alterations in sperm tail morphology were observed in the exposed group. In conclusion, exposure to mobile phone radiations induces oxidative stress in male Wistar rats which may lead to alteration in sperm parameters and affects their fertility.


Assuntos
Radiação Eletromagnética , Estresse Oxidativo/efeitos da radiação , Espécies Reativas de Oxigênio/metabolismo , Espermatozoides/efeitos da radiação , Animais , Telefone Celular , Peroxidação de Lipídeos/efeitos da radiação , Masculino , Ratos , Ratos Wistar , Contagem de Espermatozoides , Espermatozoides/metabolismo , Testículo/efeitos da radiação
20.
Arch Pharm (Weinheim) ; : e1800192, 2018 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-30537298

RESUMO

A series of spiroisoxazoline analogues of artemisinin was synthesized by employing 1,3-dipolar cycloaddition between various in situ generated nitrile oxides and artemisitene. All the synthesized compounds were tested for their anti-proliferative and anti-malarial activities. Among the compounds tested, compound 11a was found to be potent against the HCT-15 cancer cell line with IC50 = 4.04 µM when compared to 5-fluorouracil (IC50 = 35.53 µM). DNA cell cycle analysis shows that 11a was inhibiting cell proliferation at the G2/M phase. Compound 11b was found to be most active against Plasmodium falciparum with IC50 = 0.1 µM and also blocked host hemoglobin hydrolysis by the falcipain-3 receptor. It was demonstrated to have better dynamics of parasite killing efficiency than artemisinin. Molecular docking studies revealed that these compounds interacted with falcipain-3 receptor sites.

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