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Emerging Artemisinin (ART) resistance in Plasmodium falciparum (Pf) poses challenges for the discovery of novel drugs to tackle ART-resistant parasites. Concentrated efforts toward the ART resistance mechanism indicated a strong molecular link of ART resistance with upregulated expression of unfolded protein response pathways involving Prefoldins (PFDs). However, a complete characterization of PFDs as molecular players taking part in ART resistance mechanism, and discovery of small molecule inhibitors to block this process have not been identified to date. Here, we functionally characterized all Pf Prefoldin subunits (PFD1-6) and established a causative role played by PFDs in ART resistance by demonstrating their expression in intra-erythrocytic parasites along with their interactions with Kelch13 protein through immunoprecipitation coupled MS/MS analysis. Systematic biophysical interaction analysis between all subunits of PFDs revealed their potential to form a complex. The role of PFDs in ART resistance was confirmed in orthologous yeast PFD6 mutants, where PfPFD6 expression in yeast mutants reverted phenotype to ART resistance. We identified an FDA-approved drug "Biperiden" that restricts the formation of Prefoldin complex and inhibits its interaction with its key parasite protein substrates, MSP-1 and α-tubulin-I. Moreover, Biperiden treatment inhibits the parasite growth in ART-sensitive Pf3D7 and resistant Pf3D7k13R539T strains. Ring survival assays that are clinically relevant to analyze ART resistance in Pf3D7k13R539T parasites demonstrate the potency of BPD to inhibit the growth of survivor parasites. Overall, our study provides the first evidence of the role of PfPFDs in ART resistance mechanisms and opens new avenues for the management of resistant parasites.
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The present study investigated two single nucleotide polymorphisms (SNPs)-rs479200 and rs516651 in the host EGLN1/PHD2 gene for their association with COVID-19 severity. A retrospective cohort of 158 COVID-19 patients from the Indian population (March 2020 to June 2021) was enrolled. Notably, the frequency of C allele (0.664) was twofold higher than T allele (0.336) in severe COVID-19 patients. Here, we report a novel finding that the C allele of rs479200 in the EGLN1 gene imparts a high risk of severe COVID-19 (odds ratio-6.214 (1.84-20.99) p = 0.003; 9.421 (2.019-43.957) p = 0.004), in additive inheritance model (adjusted and unadjusted, respectively).
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COVID-19 , Humanos , Alelos , Estudos Retrospectivos , COVID-19/epidemiologia , COVID-19/genética , Polimorfismo de Nucleotídeo Único/genética , Povo Asiático , Predisposição Genética para Doença , Frequência do Gene , Prolina Dioxigenases do Fator Induzível por Hipóxia/genéticaRESUMO
Over the past two decades, the utilization of protein cages has witnessed exponential growth driven by their extensive applications in biotechnology and therapeutics. In the context of the recent Covid-19 pandemic, protein-cage-based scaffolds played a pivotal role in vaccine development. Beyond vaccines, these protein cages have proven valuable in diverse drug delivery applications thanks to their distinctive architecture and structural stability. Among the various types of protein cages, ferritin-based cages have taken the lead in drug delivery applications. This is primarily attributed to their ease of production, exceptional thermal stability, and nontoxic nature. While ferritin-based cages are commonly employed in anticancer drug delivery and contrast agent delivery, their efficacy in malarial drug delivery had not been explored until this study. In this investigation, several antimalarial drugs were encapsulated within horse spleen ferritin, and the binding and loading processes were validated through both experimental and computational techniques. The data unequivocally demonstrate the facile incorporation of antimalarial drugs into ferritin without disrupting its three-dimensional structure. Computational docking and molecular dynamics simulations were employed to pinpoint the precise location of the drug binding site within ferritin. Subsequent efficacy testing on Plasmodium revealed that the developed nanoconjugate, comprising the drug-ferritin conjugate, exhibited significant effectiveness in eradicating the parasite. In conclusion, the findings strongly indicate that ferritin-based carrier systems hold tremendous promise for the future of antimalarial drug delivery, offering high selectivity and limited side effects.
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Antimaláricos , Ferritinas , Ferritinas/química , Ferritinas/metabolismo , Antimaláricos/química , Antimaláricos/farmacologia , Animais , Cavalos , Sistemas de Liberação de Medicamentos/métodos , Malária/tratamento farmacológico , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Humanos , Baço/metabolismo , Plasmodium falciparum/efeitos dos fármacosRESUMO
BACKGROUND: "Kangaroo mother care," a type of newborn care involving skin-to-skin contact with the mother or other caregiver, reduces mortality in infants with low birth weight (<2.0 kg) when initiated after stabilization, but the majority of deaths occur before stabilization. The safety and efficacy of kangaroo mother care initiated soon after birth among infants with low birth weight are uncertain. METHODS: We conducted a randomized, controlled trial in five hospitals in Ghana, India, Malawi, Nigeria, and Tanzania involving infants with a birth weight between 1.0 and 1.799 kg who were assigned to receive immediate kangaroo mother care (intervention) or conventional care in an incubator or a radiant warmer until their condition stabilized and kangaroo mother care thereafter (control). The primary outcomes were death in the neonatal period (the first 28 days of life) and in the first 72 hours of life. RESULTS: A total of 3211 infants and their mothers were randomly assigned to the intervention group (1609 infants with their mothers) or the control group (1602 infants with their mothers). The median daily duration of skin-to-skin contact in the neonatal intensive care unit was 16.9 hours (interquartile range, 13.0 to 19.7) in the intervention group and 1.5 hours (interquartile range, 0.3 to 3.3) in the control group. Neonatal death occurred in the first 28 days in 191 infants in the intervention group (12.0%) and in 249 infants in the control group (15.7%) (relative risk of death, 0.75; 95% confidence interval [CI], 0.64 to 0.89; P = 0.001); neonatal death in the first 72 hours of life occurred in 74 infants in the intervention group (4.6%) and in 92 infants in the control group (5.8%) (relative risk of death, 0.77; 95% CI, 0.58 to 1.04; P = 0.09). The trial was stopped early on the recommendation of the data and safety monitoring board owing to the finding of reduced mortality among infants receiving immediate kangaroo mother care. CONCLUSIONS: Among infants with a birth weight between 1.0 and 1.799 kg, those who received immediate kangaroo mother care had lower mortality at 28 days than those who received conventional care with kangaroo mother care initiated after stabilization; the between-group difference favoring immediate kangaroo mother care at 72 hours was not significant. (Funded by the Bill and Melinda Gates Foundation; Australian New Zealand Clinical Trials Registry number, ACTRN12618001880235; Clinical Trials Registry-India number, CTRI/2018/08/015369.).
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Incubadoras para Lactentes , Recém-Nascido de Baixo Peso , Método Canguru , África Subsaariana , Aleitamento Materno , Países em Desenvolvimento , Feminino , Humanos , Índia , Lactente , Mortalidade Infantil , Recém-Nascido , Unidades de Terapia Intensiva Neonatal , Masculino , Fatores de TempoRESUMO
BACKGROUND: Hodgkin lymphoma (HL) in pediatric populations has a high survival rate but poses risks for long-term morbidities. Although [18F]fluoro2deoxy2dglucose positron emission tomography ([18F]FDG PET) scans offer potential for improved risk stratification, the definitive prognostic value of quantitative [18F]FDG PET parameters remains unclear for pediatric HL. METHODS: A single-center, retrospective study included pediatric patients diagnosed with HL between 2016 and 2023 treated according to EuroNet-PHL-C1 and DAL/GPOH-HD protocols. Patients underwent baseline and interim PET/CT scans after two chemotherapy cycles. Event-free survival (EFS) was the primary endpoint, Deauville score was the secondary endpoint. Quantitative [18F]FDG PET parameters included SUVmax, metabolic tumor volume (MTV) and total lesion glycolysis (TLG) that were evaluated using two segmentation methods (SUV 2.5, 41% SUVmax). Survival outcomes were assessed using Cox regression analysis. RESULTS: A total of 115 patients (50 males, median age 14.2 years) were studied, with a median follow-up period of 35 months. During this period, 16 cases (13.9%) of relapse or progression were noted. Baseline and interim MTV 2.5, MTV 41%, TLG 2.5, and TLG 41%, along with interim SUVmax, were significantly associated with worse EFS and correlated with post-treatment Deauville scores. In multivariable analysis, interim MTV 2.5 > 0 ml (adj. hazard ratio, HR: 3.89, p = 0.009) and interim TLG 41% ≥ 30 g (adj. HR: 7.98, p = 0.006) were independent risk factors for EFS. CONCLUSION: Baseline and interim [18F]FDG PET parameters can serve as significant prognostic indicators for EFS and treatment response in pediatric HL. These quantitative measures could enhance individualized, risk-adapted treatment strategies for children and adolescents with HL.
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Fluordesoxiglucose F18 , Doença de Hodgkin , Humanos , Doença de Hodgkin/diagnóstico por imagem , Doença de Hodgkin/metabolismo , Masculino , Feminino , Adolescente , Criança , Prognóstico , Estudos Retrospectivos , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Pré-EscolarRESUMO
The intriguing network of antibody-antigen (Ab-Ag) interactions is highly governed by environmental perturbations and the nature of biomolecular interaction. Protein-protein interactions (PPIs) have potential applications in developing protein-adsorption-based sensors and nano-scale materials. Therefore, characterizing PPIs in the presence of a nanomaterial at the molecular level becomes imperative. The present work involves the investigation of antiferritin-ferritin (Ab-Ag) protein interactions under the influence of tungsten disulfide quantum dots (WS2 QDs). Isothermal calorimetry and contact angle measurements validated the strong influence of WS2 QDs on Ab-Ag interactions. The interfacial signatures of nano-bio-interactions were evaluated using sum frequency generation vibration spectroscopy (SFG-VS) at the air-water interface. Our SFG results reveal a variation in the tilt angle of methyl groups by â¼12° ± 2° for the Ab-Ag system in the presence of WS2 QDs. The results illustrated an enhanced ordering of water molecules in the presence of QDs, which underpins the active role of interfacial water molecules during nano-bio-interactions. We have also witnessed a differential impact of QDs on Ab-Ag by raising the concentration of the Ab-Ag combination, which showcased an increased inter-molecular interaction among the Ab and Ag molecules and a minimal influence on the methyl tilt angle. These findings suggest the formation of stronger and ordered Ab-Ag complexes upon introducing WS2 QDs in the aqueous medium and signify the potentiality of WS2 QDs relevant to protein-based sensing assays.
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Pontos Quânticos , Compostos de Tungstênio , Pontos Quânticos/química , Água/química , Sulfetos/químicaRESUMO
The specificity of ions in inducing conformational changes in macromolecules is introduced as the Hofmeister series; however, the detailed underlying mechanism is not comprehensible yet. We utilized surface-specific sum frequency generation (SFG) vibrational spectroscopy to explore the Hofmeister effect at the air/polyvinylpyrrolidone (PVP)/water interface. The spectral signature observed from the ssp polarization scheme reveals ion-specific ordering of water molecules following the Hofmeister series attributed to the ion-macromolecule interactions. Along with this, the presence of ions does not reflect any significant influence on the structure of the PVP macromolecule. However, the ppp-SFG spectra in the CH-stretch region reveal the impact of ions on the orientation angle of vinyl chain CH2-groups, which follows the Hofmeister series: SO42- > Cl- > NO3- > Br- > ClO4- > SCN-. The minimal orientation angle of CH2-groups indicates significant reordering in PVP vinyl chains in the presence of chaotropic anions ClO4-, and SCN-. The observation is attributed to the ion-specific water-macromolecule interactions at the air/aqueous interface. It is compelling to observe the signature of spectral blue shifts in the OH-stretch region in the ppp configuration in the presence of chaotropic anions. The origin of spectral blue shifts has been ascribed to the existence of weaker interactions between the interfacial water molecules and the backbone CH- and CH2-moieties of the PVP macromolecules. The ion-specific modulation in water-macromolecule interactions is endorsed by the relative propensity of anion's adsorption toward the air/aqueous interface. The experimental findings highlight the existence and cooperative participation of ion-specific water-macromolecule interactions in the mechanism of the Hofmeister effect, along with the illustrious ion-water and ion-macromolecule interactions.
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Addressing nutritional deficiencies in food crops through biofortification is a sustainable approach to tackling malnutrition. Biofortification is continuously being attempted through conventional breeding as well as through various plant biotechnological interventions, ranging from molecular breeding to genetic engineering and genome editing for enriching crops with various health-promoting metabolites. Genetic engineering is used for the rational incorporation of desired nutritional traits in food crops and predominantly operates through nuclear and chloroplast genome engineering. In the recent past, chloroplast engineering has been deployed as a strategic tool to develop model plants with enhanced nutritional traits due to the various advantages it offers over nuclear genome engineering. However, this approach needs to be extended for the nutritional enhancement of major food crops. Further, this platform could be combined with strategies, such as synthetic biology, chloroplast editing, nanoparticle-mediated rapid chloroplast transformation, and horizontal gene transfer through grafting for targeting endogenous metabolic pathways for overproducing native nutraceuticals, production of biopharmaceuticals, and biosynthesis of designer nutritional compounds. This review focuses on exploring various features of chloroplast genome engineering for nutritional enhancement of food crops by enhancing the levels of existing metabolites, restoring the metabolites lost during crop domestication, and introducing novel metabolites and phytonutrients needed for a healthy daily diet.
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Drought is the most prevalent environmental stress that affects plants' growth, development, and crop productivity. However, plants have evolved adaptive mechanisms to respond to the harmful effects of drought. They reprogram their: transcriptome, proteome, and metabolome that alter their cellular and physiological processes and establish cellular homeostasis. One of the crucial regulatory processes that govern this reprogramming is post-transcriptional regulation by microRNAs (miRNAs). miRNAs are small non-coding RNAs, involved in the downregulation of the target mRNA via translation inhibition/mRNA degradation/miRNA-mediated mRNA decay/ribosome drop off/DNA methylation. Many drought-inducible miRNAs have been identified and characterized in plants. Their main targets are regulatory genes that influence growth, development, osmotic stress tolerance, antioxidant defense, phytohormone-mediated signaling, and delayed senescence during drought stress. Overexpression of drought-responsive miRNAs (Osa-miR535, miR160, miR408, Osa-miR393, Osa-miR319, and Gma-miR394) in certain plants has led to tolerance against drought stress indicating their vital role in stress mitigation. Similarly, knock down (miR166/miR398c) or deletion (miR169 and miR827) of miRNAs has also resulted in tolerance to drought stress. Likewise, engineered Arabidopsis plants with miR165, miR166 using short tandem target mimic strategy, exhibited drought tolerance. Since miRNAs regulate the expression of an array of drought-responsive genes, they can act as prospective targets for genetic manipulations to enhance drought tolerance in crops and achieve sustainable agriculture. Further investigations toward functional characterization of diverse miRNAs, and understanding stress-responses regulated by these miRNAs and their utilization in biotechnological applications is highly recommended.
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Secas , MicroRNAs , MicroRNAs/genética , Plantas/metabolismo , Transcriptoma , Estresse Fisiológico/genética , Regulação da Expressão Gênica de PlantasRESUMO
BACKGROUND: Enhanced Recovery After Surgery (ERAS) is a multimodal approach with promising results in improving patient outcome. Only recently, is evidence emerging highlighting how similar principles of care can be applied to patients undergoing emergency abdominal surgery. METHODS: A randomized controlled trial was conducted from November 2021 to April 2022 at PGIMER Chandigarh, which is a leading tertiary care hospital in northern India. 60 patients with acute intestinal obstruction requiring emergency laparotomy were randomized and assigned to ERAS or Non-ERAS group. ERAS protocol with some modifications was applied. Primary endpoints were post-operative hospital stay. Secondary end points were morbidity, 30-day readmission and mortality rate. Data analysis was done using SPSS 22.0. Independent t test or Mann-Whitney test and Chi-square or Fisher-exact test were used for analysis. RESULTS: A significant 3-day reduction in hospital stay was observed in ERAS compared to non-ERAS group (median (interquartile range) 5.50 (4.75-8.25) vs 8.0 (6.0-11.0) p = 0.003) with no difference in 30-day readmission rate, mortality rate and complication rate (according to Clavien-Dindo classification). ERAS group was associated with early recovery of gastrointestinal functions including time to first passage of flatus (p < 0.001), stools (p = 0.014), early ambulation (p < 0.001), time to first fluid diet (p < 0.001), solid diet (p = 0.001) and reduced nasogastric tube reinsertion rates (p = 0.01) despite its early removal. CONCLUSION: ERAS with some modifications can be applied in patients with intestinal obstruction. Thus, we can expedite post-operative recovery and early regain of gastrointestinal function with decreased hospital stay, comparable morbidity and mortality. Further studies are needed to assess ERAS role in emergency gastrointestinal surgeries. Trial registration Ctri.gov Identifier: CTRI/2022/04/042156.
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Procedimentos Cirúrgicos do Sistema Digestório , Recuperação Pós-Cirúrgica Melhorada , Obstrução Intestinal , Humanos , Procedimentos Cirúrgicos do Sistema Digestório/efeitos adversos , Procedimentos Cirúrgicos do Sistema Digestório/métodos , Obstrução Intestinal/etiologia , Obstrução Intestinal/cirurgia , Laparotomia/efeitos adversos , Tempo de Internação , Complicações Pós-Operatórias/etiologiaAssuntos
Caspases/classificação , Proteína de Translocação 1 do Linfoma de Tecido Linfoide Associado à Mucosa/classificação , Proteínas de Plantas/classificação , Terminologia como Assunto , Animais , Caspases/química , Caspases/metabolismo , Consenso , Humanos , Proteína de Translocação 1 do Linfoma de Tecido Linfoide Associado à Mucosa/química , Proteína de Translocação 1 do Linfoma de Tecido Linfoide Associado à Mucosa/metabolismo , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Conformação Proteica , Relação Estrutura-AtividadeRESUMO
The potato cyst nematode (Globodera rostochiensis) is one of the most economically important pests of potato (Solanum tuberosum L.), causing significant economic losses worldwide. The identification of biocontrol agents for the sustainable management of G. rostochiensis is crucial. In this study, a potential biocontrol agent, Chaetomium globosum KPC3, was identified based on sequence analysis of the DNA internal transcribed spacer (ITS) region, the translation elongation factor 1-alpha (TEF1-α) gene, and the second largest subunit of the RNA polymerase II (RPB2) gene. The pathogenicity test of C. globosum KPC3 against cysts and second-stage juveniles (J2s) revealed that fungus mycelium fully parasitized the cyst after 72 h of incubation. The fungus was also capable of parasitizing the eggs inside the cysts. The culture filtrate of C. globosum KPC3 caused 98.75% mortality in J2s of G. rostochiensis after 72 h of incubation. The pot experiments showed that the combined application of C. globosum KPC3 as a tuber treatment at a rate of 1 lit kg-1 of tubers and a soil application at a rate of 500 ml kg-1 of farm yard manure (FYM) resulted in significantly lesser reproduction of G. rostochiensis compared to the rest of the treatments. Altogether, C. globosum KPC3 has the potential to be used as a biocontrol agent against G. rostochiensis and can be successfully implemented in integrated pest management programs.
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Chaetomium , Cistos , Nematoides , Solanum tuberosum , AnimaisRESUMO
Evaporation is an interfacial phenomenon in which a water molecule breaks the intermolecular hydrogen (H-) bonds and enters the vapor phase. However, a detailed demonstration of the role of interfacial water structure in the evaporation process is still lacking. Here, we purposefully perturb the H-bonding environment at the air/water interface by introducing kosmotropic (HPO4-2, SO4-2, and CO3-2) and chaotropic ions (NO3- and I-) to determine their influence on the evaporation process. Using time-resolved interferometry on aqueous salt droplets, we found that kosmotropes reduce evaporation, whereas chaotropes accelerate the evaporation process, following the Hofmeister series: HPO4-2 < SO4-2 < CO3-2 < Cl- < NO3- < I-. To extract deeper molecular-level insights into the observed Hofmeister trend in the evaporation rates, we investigated the air/water interface in the presence of ions using surface-specific sum frequency generation (SFG) vibrational spectroscopy. The SFG vibrational spectra reveal the significant impact of ions on the strength of the H-bonding environment and the orientation of free OH oscillators from â¼36.2 to 48.4° at the air/water interface, where both the effects follow the Hofmeister series. It is established that the slow evaporating water molecules experience a strong H-bonding environment with free OH oscillators tilted away from the surface normal in the presence of kosmotropes. In contrast, the fast evaporating water molecules experience a weak H-bonding environment with free OH oscillators tilted toward the surface normal in the presence of chaotropes at the air/water interface. Our experimental outcomes showcase the complex bonding environment of interfacial water molecules and their decisive role in the evaporation process.
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Vibração , Água , Hidrogênio , Íons/química , Análise Espectral , Água/químicaRESUMO
The structural properties of the polyethylenimine (PEI) polymer are generally tuned and selectively modified to reinforce its potential in a broad spectrum of applied domains of medicine, healthcare, material design, sensing, and electronic optimization. The selective modification of the polymer brings about changes in its interfacial characteristics and behavior. The current work involves the synthesis of naphthalimide conjugated polyethylenimine organic nanoparticles (NPEI-ONPs). The interfacial molecular structure of NPEI-ONPs is explored in an aqueous medium at pH 7.4 using surface tensiometry and sum-frequency generation vibrational spectroscopy (SFG-VS). The hydrophobic functionalization rendered a concentration-dependent surface coverage of NPEI-ONPs, where the SFG-VS analysis exhibited the molecular rearrangement of its hydrophobic groups at the interface. The interaction of NPEI-ONPs with double-stranded DNA (dsDNA) is carried out to observe the relevance of the synthesized nanocomposites in the biomedical domain. The bulk-specific studies (i.e., thermal denaturation, viscometry, zeta (ζ) potential, and ATR-FTIR) reveal the condensation of dsDNA in the presence of NPEI-ONPs, making its structure more compact. The interface-sensitive SFG-VS showcased the impact of the dsDNA and NPEI-ONP interaction on the interfacial molecular behavior of NPEI-ONPs at the air-aqueous interface. Our results exhibit the potential of such hydrophobically functionalized ONPs as promising candidates for developing biomedical sealants, substrate coatings, and other biomedical domains.
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Nanopartículas , Polietilenoimina , Polietilenoimina/química , Estrutura Molecular , Nanopartículas/química , Polímeros/química , DNA , ÁguaRESUMO
The emergence of drug-resistant parasites and/or insecticide-resistant mosquito vectors necessitates developing alternative tools that either supplement or replace the conventional malaria control strategies. Trans-infecting the mosquito vector with symbionts that can either compete with a targeted pathogen or manipulate the host biology by reducing its vectorial capacity could be a promising and innovative biological approach for the control of infectious diseases This idea could be utilized to develop a novel and efficient vector control strategy; symbionts are dispersed into vector populations to reduce their ability to transmit human pathogens. Here, we reported the natural existence of Microsporidian (an obligate fungus) in the field-collected An. stephensi mosquito. However, laboratory-reared An. stephensi and An. culicifacies did not exhibit microsporidian infection. Similarly, 16s rRNA PCR identified â¼1kb amplicons in laboratory-reared An. stephensi and An. culicifacies, indicating the presence of naturally residing different bacterial species. DNA sequencing of these amplicons revealed the identities of different bacteria which are not well-characterized in terms of plasmodia-interaction activity in the Indian malaria vector. This article summarizes an overview of the previously studied microbial symbionts for their role in Plasmodium transmission along with a list of new or unexplored symbionts in the disease transmitting mosquito vectors. The summarized information could be utilized to explore such microbial symbionts for their role in Plasmodium-transmission biology in-depth and implementation in the malaria control interventions globally.
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Anopheles , Inseticidas , Malária , Animais , Humanos , Mosquitos Vetores , Anopheles/parasitologia , Malária/prevenção & controle , Malária/parasitologia , RNA Ribossômico 16S/genética , BactériasRESUMO
Supersaturated drug delivery system (SDDS) enables the solubility and sustained membrane transport of poorly water-soluble drugs. SDDS provides higher drug concentration in the dispersed phase and equilibrium in the continuous phase, which corresponds to amorphous solubility of the drug. Rifaximin (RFX) is a nonabsorbable BCS class IV drug approved for the treatment of irritable bowel syndrome and effective against Helicobacter pylori. RFX shows slow crystallization and precipitation in an acidic pH of 1.2-2, leading to obliteration of its activity in the gastrointestinal tract. The objective of the present study is to inhibit the precipitation of RFX, involving screening of polymers at different concentrations, using an in-house developed microarray plate method and solubility studies which set forth hydroxypropyl methylcellulose (HPMC) E15, Soluplus, and polyvinyl alcohol to be effective precipitation inhibitors (PIs). Drug-polymer precipitates (PPTS) are examined for surface morphology by scanning electron microscopy, solid-phase transformation by hot stage microscopy, the nature of PPTS by polarized light microscopy, and drug-polymer interactions by Fourier transform infrared and nuclear magnetic resonance spectroscopy. Besides, the unfathomed molecular mechanism of drug-polymer interplay is discerned at the air-water interface using sum-frequency generation spectroscopy to correlate the interfacial hydrogen bonding properties in bulk water. Surprisingly, all studies disseminate HPMC E15 and Soluplus as effective PIs of RFX.
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Sistemas de Liberação de Medicamentos/métodos , Excipientes Farmacêuticos/química , Polímeros/química , Rifaximina/química , Química Farmacêutica , Cristalização , Ligação de Hidrogênio , Rifaximina/administração & dosagem , SolubilidadeRESUMO
Metacaspases are novel cysteine proteases found in apicomplexan whose function is poorly understood. Our earlier studies on Plasmodium falciparum metacaspase-2 (PfMCA-2) revealed that the caspase inhibitor, Z-FA-FMK efficiently inhibited PfMCA-2 activity and, expression, and significantly blocked in vitro progression of the parasite developmental cycle via apoptosis-like parasite death. Building on these findings, we synthesized a set of novel inhibitors based on structural modification of Z-FA-FMK with the amides of piperic acid and investigated their effect on PfMCA-2. One of these analogs, SS-5, specifically inhibited the activity and expression of PfMCA-2. The activities of some other known malarial proteases (falcipains, plasmepsins and vivapain), and human cathepsins-B, D and L, and caspase-3 and -7 were not inhibited by SS-5. SS-5 blocked the development of P. falciparum in vitro (IC50 1â µM) and caused prominent morphological distortions. Incubation with SS-5 led to persistent parasite oxidative stress accompanied by depolarization of mitochondrial potential and accumulation of intracellular Ca2+. SS-5 also inhibited the development of P. berghei in a murine model. Our results suggest that the inhibition of PfMCA-2 results in oxidative stress, leading to apoptosis-like parasite death. Thus, SS-5 offers a starting point for the optimization of new antimalarials, and PfMCA-2 could be a novel target for antimalarial drug discovery.
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Apoptose/efeitos dos fármacos , Proteínas de Bactérias/metabolismo , Cisteína Endopeptidases/metabolismo , Inibidores de Cisteína Proteinase/farmacologia , Dipeptídeos/farmacologia , Cetonas/farmacologia , Plasmodium falciparum/enzimologia , Amidas/química , Animais , Antimaláricos/química , Antimaláricos/farmacologia , Proteínas de Bactérias/antagonistas & inibidores , Sobrevivência Celular/efeitos dos fármacos , Dipeptídeos/química , Descoberta de Drogas/métodos , Ácidos Graxos Insaturados/química , Feminino , Células Hep G2 , Humanos , Cetonas/química , Malária Falciparum/tratamento farmacológico , Malária Falciparum/parasitologia , Masculino , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Estresse Oxidativo/efeitos dos fármacosRESUMO
The immune blood cells "hemocytes" of mosquitoes impart a highly selective immune response against various microorganisms/pathogens. Among several immune effectors, fibrinogen-related proteins (FREPs) have been recognized as key modulators of cellular immune responses; however, their physiological relevance has not been investigated in detail. Our ongoing comparative RNA-sequencing analysis identified a total of 13 FREPs originating from naïve sugar-fed, blood-fed, bacterial challenged and Plasmodium vivax-infected hemocytes in Anopheles stephensi. Transcriptional profiling of the selected seven FREP transcripts showed distinct responses against different pathophysiological conditions, where an exclusive induction of FREP12 after 10 days of P. vivax infection was observed. This represents a possible role of FREP12 in immunity against free circulating sporozoites and needs to be explored in the future. When challenged with live bacterial injection in the thorax, we observed a higher affinity of FREP13 and FREP65 toward Gram-negative and Gram-positive bacteria in the mosquito hemocytes, respectively. Furthermore, we observed increased bacterial survival and proliferation, which is likely compromised by the downregulation of TEP1, in FREP13 messenger RNA-depleted mosquito hemolymph. In contrast, after blood-feeding, we also noticed a significant delay of 24 h in the enrichment of gut endosymbionts in the FREP13-silenced mosquitoes. Taken together, we conclude that hemocyte-specific FREP13 carries the unique ability of tissue-specific regulation, having an antagonistic antibacterial role in the hemolymph, and an agonistic role against gut endosymbionts.
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Anopheles , Microbioma Gastrointestinal , Hemócitos/parasitologia , Hemolinfa/microbiologia , Proteínas de Insetos/genética , Animais , Anopheles/imunologia , Bactérias , Plasmodium vivax , Esporozoítos , SimbioseRESUMO
This article has been retracted. Please see the Retraction Notice for more detail: https://doi.org/10.1007/s11095-020-02971-0.