Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 96
Filtrar
1.
PLoS One ; 19(4): e0294823, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38640099

RESUMEN

BACKGROUND: Despite eradication efforts, ~135,000 African children sustained brain injuries as a result of central nervous system (CNS) malaria in 2021. Newer antimalarial medications rapidly clear peripheral parasitemia and improve survival, but mortality remains high with no associated decline in post-malaria neurologic injury. A randomized controlled trial of aggressive antipyretic therapy with acetaminophen and ibuprofen (Fever RCT) for malarial fevers being conducted in Malawi and Zambia began enrollment in 2019. We propose to use neuroimaging in the context of the RCT to further evaluate neuroprotective effects of aggressive antipyretic therapy. METHODS: This observational magnetic resonance imaging (MRI) ancillary study will obtain neuroimaging and neurodevelopmental and behavioral outcomes in children previously enrolled in the Fever RCT at 1- and 12-months post discharge. Analysis will compare the odds of any brain injury between the aggressive antipyretic therapy and usual care groups based upon MRI structural abnormalities. For children unable to undergo imaging without deep sedation, neurodevelopmental and behavioral outcomes will be used to identify brain injury. DISCUSSION: Neuroimaging is a well-established, valid proxy for neurological outcomes after brain injury in pediatric CNS malaria. This MRI ancillary study will add value to the Fever RCT by determining if treatment with aggressive antipyretic therapy is neuroprotective in CNS malaria. It may also help elucidate the underlying mechanism(s) of neuroprotection and expand upon FEVER RCT safety assessments.


Asunto(s)
Antipiréticos , Lesiones Encefálicas , Malaria , Humanos , Niño , Antipiréticos/uso terapéutico , Cuidados Posteriores , Alta del Paciente , Fiebre/complicaciones , Fiebre/tratamiento farmacológico , Fiebre/prevención & control , Imagen por Resonancia Magnética , Ensayos Clínicos Controlados Aleatorios como Asunto , Estudios Observacionales como Asunto
2.
Biomolecules ; 14(4)2024 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-38672479

RESUMEN

Polyamines are polycations derived from amino acids that play an important role in proliferation and growth in almost all living cells. In Streptococcus pneumoniae (the pneumococcus), modulation of polyamine metabolism not only plays an important regulatory role in central metabolism, but also impacts virulence factors such as the capsule and stress responses that affect survival in the host. However, functional annotation of enzymes from the polyamine biosynthesis pathways in the pneumococcus is based predominantly on computational prediction. In this study, we cloned SP_0166, predicted to be a pyridoxal-dependent decarboxylase, from the Orn/Lys/Arg family pathway in S. pneumoniae TIGR4 and expressed and purified the recombinant protein. We performed biochemical characterization of the recombinant SP_0166 and confirmed the substrate specificity. For polyamine analysis, we developed a simultaneous quantitative method using hydrophilic interaction liquid chromatography (HILIC)-based liquid chromatography-tandem mass spectrometry (LC-MS/MS) without derivatization. SP_0166 has apparent Km, kcat, and kcat/Km values of 11.3 mM, 715,053 min-1, and 63,218 min-1 mM-1, respectively, with arginine as a substrate at pH 7.5. We carried out inhibition studies of SP_0166 enzymatic activity with arginine as a substrate using chemical inhibitors DFMO and DFMA. DFMO is an irreversible inhibitor of ornithine decarboxylase activity, while DFMA inhibits arginine decarboxylase activity. Our findings confirm that SP_0166 is inhibited by DFMA and DFMO, impacting agmatine production. The use of arginine as a substrate revealed that the synthesis of putrescine by agmatinase and N-carbamoylputrescine by agmatine deiminase were both affected and inhibited by DFMA. This study provides experimental validation that SP_0166 is an arginine decarboxylase in pneumococci.


Asunto(s)
Carboxiliasas , Streptococcus pneumoniae , Espectrometría de Masas en Tándem , Carboxiliasas/metabolismo , Carboxiliasas/genética , Carboxiliasas/química , Streptococcus pneumoniae/enzimología , Streptococcus pneumoniae/genética , Cromatografía Líquida de Alta Presión , Especificidad por Sustrato , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/genética , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/genética , Poliaminas/metabolismo , Cinética
3.
Afr J Prim Health Care Fam Med ; 16(1): e1-e11, 2024 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-38426769

RESUMEN

BACKGROUND: Community health workers (CHWs) bridge the primary health care (PHC) system and communities by providing care in the household. In Malawi, few studies have examined the perspective of users of household-level CHW services, in remote areas, to understand CHW's role in community-based PHC. AIM: To explore perspectives of community and facility stakeholders on the enablers and challenges of the CHW role in community-based PHC in Neno District. SETTING: The study was conducted in the Neno District health facilities, namely, Ligowe, Dambe, Chifunga, and Zalewa. METHODS: We conducted eight focus group discussions (FGDs) with purposively sampled community members and conveniently sampled facility stakeholders. Data were transcribed and analysed thematically through an adapted COM-B model of behaviour change. RESULTS: Three main themes of perceived behaviour change within the CHW role were identified: (1) capacity - the CHW programme aids health education and promotion within the community; (2) opportunity - the CHW programme facilitates community-based PHC and linkage to the facility; and (3) motivation - the CHW programme enablers and challenges in providing community-based PHC. CONCLUSION: Community health workers enrich community-based PHC delivery through health education, timely access to care, and linking communities to the facility. Optimising workload and programme support is critical for the help of CHWs. Further studies are required to address programme and cultural challenges to enhance positive health-seeking behaviours.Contribution: This study provides contextual knowledge for further research on bringing together spiritual and formal health practices and considering the cultural background when planning for health interventions in remote areas.


Asunto(s)
Agentes Comunitarios de Salud , Atención a la Salud , Humanos , Malaui , Educación en Salud , Grupos Focales , Investigación Cualitativa
4.
IBRO Neurosci Rep ; 16: 443-454, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38544793

RESUMEN

Calabash chalk (CaC) is an aluminium silicate hydroxide compound with heavy metal constituents, making it a potential neurotoxicant. Pregnant women often consume CaC as an antiemetic, which may interfere with the normal development of the foetal brain. Here, we evaluated the effects of CaC administration in pregnant rats on the brain of the offspring. Wistar rat dams were assigned to one of three groups: control, 200 mg/kg and 800 mg/kg of a CaC suspension. Administrations lasted 14 days (gestation days 7-20). On day 14, 5-bromo-2'-deoxyuridine (BrdU) was administered and dams were allowed to term. Behavioural tests were performed on different days as the pups matured, and they were sacrificed on post-natal days 30 and 60. Brains were processed for histology and Western blotting. Results showed no significant differences in surface righting reflex, cliff avoidance, negative geotaxis and open-field activity. No hippocampal and somatosensory cortical cytoarchitectonic alterations and no significant signs of glial fibrillary acidic protein (GFAP) activation were observed. Neuronal nuclei counts showed variability in the somatosensory cortex and hippocampus of the CaC group. BrdU-positive cells were significantly lower in the 200 mg/kg group and higher in the 800 mg/kg group. Doublecortin-X-positive cells were not different in all the CaC groups. Astrocytes and microglia Western blotting quantification confirmed no significant increase in pup glial cells in adulthood. Prenatal consumption of CaC at indicated dosages may not be deleterious to the developing brain, especially after cessation of exposure and during maturation of the animal. However, the differences in neuronal and glial populations may be due to their ability to cope with CaC.

5.
Biomolecules ; 14(2)2024 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-38397415

RESUMEN

Streptococcus pneumoniae (Spn), a Gram-positive bacterium, poses a significant threat to human health, causing mild respiratory infections to severe invasive conditions. Despite the availability of vaccines, challenges persist due to serotype replacement and antibiotic resistance, emphasizing the need for alternative therapeutic strategies. This study explores the intriguing role of polyamines, ubiquitous, small organic cations, in modulating virulence factors, especially the capsule, a crucial determinant of Spn's pathogenicity. Using chemical inhibitors, difluoromethylornithine (DFMO) and AMXT 1501, this research unveils distinct regulatory effects on the gene expression of the Spn D39 serotype in response to altered polyamine homeostasis. DFMO inhibits polyamine biosynthesis, disrupting pathways associated with glucose import and the interconversion of sugars. In contrast, AMXT 1501, targeting polyamine transport, enhances the expression of polyamine and glucose biosynthesis genes, presenting a novel avenue for regulating the capsule independent of glucose availability. Despite ample glucose availability, AMXT 1501 treatment downregulates the glycolytic pathway, fatty acid synthesis, and ATP synthase, crucial for energy production, while upregulating two-component systems responsible for stress management. This suggests a potential shutdown of energy production and capsule biosynthesis, redirecting resources towards stress management. Following DFMO and AMXT 1501 treatments, countermeasures, such as upregulation of stress response genes and ribosomal protein, were observed but appear to be insufficient to overcome the deleterious effects on capsule production. This study highlights the complexity of polyamine-mediated regulation in S. pneumoniae, particularly capsule biosynthesis. Our findings offer valuable insights into potential therapeutic targets for modulating capsules in a polyamine-dependent manner, a promising avenue for intervention against S. pneumoniae infections.


Asunto(s)
Eflornitina , Streptococcus pneumoniae , Humanos , Eflornitina/farmacología , Streptococcus pneumoniae/genética , Poliaminas/metabolismo , Glucosa/metabolismo , Expresión Génica
6.
Microorganisms ; 12(1)2024 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-38257961

RESUMEN

Salmonella spp., a leading cause of foodborne illness, is a formidable global menace due to escalating antimicrobial resistance (AMR). The evaluation of minimum inhibitory concentration (MIC) for antimicrobials is critical for characterizing AMR. The current whole genome sequencing (WGS)-based approaches for predicting MIC are hindered by both computational and feature identification constraints. We propose an innovative methodology called the "Genome Feature Extractor Pipeline" that integrates traditional machine learning (random forest, RF) with deep learning models (multilayer perceptron (MLP) and DeepLift) for WGS-based MIC prediction. We used a dataset from the National Antimicrobial Resistance Monitoring System (NARMS), comprising 4500 assembled genomes of nontyphoidal Salmonella, each annotated with MIC metadata for 15 antibiotics. Our pipeline involves the batch downloading of annotated genomes, the determination of feature importance using RF, Gini-index-based selection of crucial 10-mers, and their expansion to 20-mers. This is followed by an MLP network, with four hidden layers of 1024 neurons each, to predict MIC values. Using DeepLift, key 20-mers and associated genes influencing MIC are identified. The 10 most significant 20-mers for each antibiotic are listed, showcasing our ability to discern genomic features affecting Salmonella MIC prediction with enhanced precision. The methodology replaces binary indicators with k-mer counts, offering a more nuanced analysis. The combination of RF and MLP addresses the limitations of the existing WGS approach, providing a robust and efficient method for predicting MIC values in Salmonella that could potentially be applied to other pathogens.

7.
Anim Microbiome ; 5(1): 57, 2023 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-37968727

RESUMEN

BACKGROUND: Microbiomes that can serve as an indicator of gut, intestinal, and general health of humans and animals are largely influenced by food consumed and contaminant bioagents. Microbiome studies usually focus on estimating the alpha (within sample) and beta (similarity/dissimilarity among samples) diversities. This study took a combinatorial approach and applied machine learning to microbiome data to predict the presence of disease-causing pathogens and their association with known/potential probiotic taxa. Probiotics are beneficial living microorganisms capable of improving the host organism's digestive system, immune function and ultimately overall health. Here, 16 S rRNA gene high-throughput Illumina sequencing of temporal pre-harvest (feces, soil) samples of 42 pastured poultry flocks (poultry in this entire work solely refers to chickens) from southeastern U.S. farms was used to generate the relative abundance of operational taxonomic units (OTUs) as machine learning input. Unique genera from the OTUs were used as predictors of the prevalence of foodborne pathogens (Salmonella, Campylobacter and Listeria) at different stages of poultry growth (START (2-4 weeks old), MID (5-7 weeks old), END (8-11 weeks old)), association with farm management practices and physicochemical properties. RESULT: While we did not see any significant associations between known probiotics and Salmonella or Listeria, we observed significant negative correlations between known probiotics (Bacillus and Clostridium) and Campylobacter at the mid-time point of sample collection. Our data indicates a negative correlation between potential probiotics and Campylobacter at both early and end-time points of sample collection. Furthermore, our model prediction shows that changes in farm operations such as how often the houses are moved on the pasture, age at which chickens are introduced to the pasture, diet composition and presence of other animals on the farm could favorably increase the abundance and activity of probiotics that could reduce Campylobacter prevalence. CONCLUSION: Integration of microbiome data with farm management practices using machine learning provided insights on how to reduce Campylobacter prevalence and transmission along the farm-to-fork continuum. Altering management practices to support proliferation of beneficial probiotics to reduce pathogen prevalence identified here could constitute a complementary method to the existing but ineffective interventions such as vaccination and bacteriophage cocktails usage. Study findings also corroborate the presence of bacterial genera such as Caloramator, DA101, Parabacteroides and Faecalibacterium as potential probiotics.

8.
medRxiv ; 2023 Nov 10.
Artículo en Inglés | MEDLINE | ID: mdl-37986869

RESUMEN

Background: Despite eradication efforts, ~135,000 African children sustained brain injuries as a result of central nervous system (CNS) malaria in 2021. Newer antimalarial medications rapidly clear peripheral parasitemia and improve survival, but mortality remains high with no associated decline in post-malaria neurologic injury. A randomized controlled trial of aggressive antipyretic therapy with acetaminophen and ibuprofen (Fever RCT) for malarial fevers being conducted in Malawi and Zambia began enrollment in 2019. We propose to use neuroimaging in the context of the RCT to further evaluate neuroprotective effects of aggressive antipyretic therapy. Methods: This observational magnetic resonance imaging (MRI) ancillary study will obtain neuroimaging and neurodevelopmental and behavioral outcomes in children previously enrolled in the Fever RCT at 1- and 12-months post discharge. Analysis will compare the odds of any brain injury between the aggressive antipyretic therapy and usual care groups based upon MRI structural abnormalities. For children unable to undergo imaging without deep sedation, neurodevelopmental and behavioral outcomes will be used to identify brain injury. Discussion: Neuroimaging is a well-established, valid proxy for neurological outcomes after brain injury in pediatric CNS malaria. This MRI ancillary study will add value to the Fever RCT by determining if treatment with aggressive antipyretic therapy is neuroprotective in CNS malaria. It may also help elucidate the underlying mechanism(s) of neuroprotection and expand upon FEVER RCT safety assessments.

9.
Lancet Glob Health ; 11(6): e917-e923, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37202026

RESUMEN

BACKGROUND: Novel oral poliovirus vaccine type 2 (nOPV2) was administered in Liberia in response to an outbreak of circulating vaccine-derived poliovirus type 2 (cVDPV2) in 2021. We conducted a serological survey of polio antibodies after two national campaigns with nOPV2. METHODS: This clustered, cross-sectional, population-based seroprevalence survey was conducted in children aged 0-59 months, more than 4 weeks after the second nOPV2 vaccination round. We used a clustered sampling method in four geographical regions of Liberia, followed by a simple random sampling of households. One eligible child was randomly selected per household. Dried blood spot specimens were taken and vaccination history was recorded. The antibody titres against all three poliovirus serotypes were assessed using standard microneutralisation assays done at the US Centers for Disease Control and Prevention in Atlanta, GA, USA. FINDINGS: Analysable data were obtained from 436 (87%) of 500 enrolled participants. Of these, 371 (85%) children were reported via parental recall to have received two nOPV2 doses, 43 (10%) received one dose, and 22 (5%) received no doses. The seroprevalence against type 2 poliovirus was 38·3% (95% CI 33·7-43·0; 167 of 436 participants). No significant difference was observed between type 2 seroprevalence in children aged 6 months or older who were reported to have received two doses of nOPV2 (42·1%, 95% CI 36·8-47·5; 144 of 342), one dose (28·0%, 12·1-49·4; seven of 25), or no doses (37·5%, 8·5-75·5; three of eight; p=0·39). The seroprevalence against type 1 was 59·6% (54·9-64·3; 260 of 436), and the seroprevalence against type 3 was 53·0% (48·2-57·7; 231 of 436). INTERPRETATION: Unexpectedly, the data showed low type 2 seroprevalence after two reported doses of nOPV2. This finding is probably affected by the lower oral poliovirus vaccine immunogenicity previously demonstrated in resource-limited settings, with high prevalence of chronic intestinal infections in children and other factors discussed herein. Our results provide the first assessment of nOPV2 performance in outbreak response in the African region. FUNDING: WHO and Rotary International.


Asunto(s)
Poliomielitis , Poliovirus , Niño , Humanos , Lactante , Vacuna Antipolio Oral , Estudios Seroepidemiológicos , Estudios Transversales , Liberia/epidemiología , Poliomielitis/epidemiología , Poliomielitis/prevención & control , Anticuerpos Antivirales
11.
Afr J Prim Health Care Fam Med ; 14(1): e1-e4, 2022 Dec 14.
Artículo en Inglés | MEDLINE | ID: mdl-36546498

RESUMEN

In the third week of January 2022, the southern districts of Malawi were hit by Cyclone Ana. The worst affected areas were Chikwawa and Nsanje. Four weeks following Cyclone Ana, a rather smaller cyclone, Dumako, hit the same areas, causing more damage. The Partners in Health or Abwenzi Pa Za Umoyo, an international humanitarian nongovernmental organisation that provides primary health care (PHC), organised teams to join Chikwawa District Council - Health, providing PHC assistance in the most affected district (Chikwawa); these teams were joined by three senior residents in family medicine from Kamuzu University of Health Sciences.Contribution: From the experiences of the interventions reported here, it was learnt that a multidisciplinary team of PHC providers is the key to the success of the emergency PHC programmes in times of natural disasters. While immediate PHC may be important at the actual time of disaster, it was learnt that PHC is also very important for continuation of care for chronic conditions, antenatal clinics and other clinics that are interrupted by the disaster. The experiences emphasised the importance of involving the PHC physicians and other PHC cadres in planning PHC programmes in natural disaster-prone areas.


Asunto(s)
Tormentas Ciclónicas , Humanos , Femenino , Embarazo , Malaui
12.
Heliyon ; 8(11): e11331, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36406675

RESUMEN

Animal sourced foods including contaminated poultry meat and eggs contribute to human non-typhoidal salmonellosis, a foodborne zoonosis. Prevalence of Salmonella in pastured poultry production systems can lead to contamination of the final product. Identification of farm practices that affect Salmonella prevalence is critical for implementing control measures to ensure the safety of these products. In this study, we developed predictive models based predominantly on deep learning approaches to identify key pre-harvest management variables (using soil and feces samples) in pastured poultry farms that contribute to Salmonella prevalence. Our ensemble approach utilizing five different machine learning techniques predicts that physicochemical parameters of the soil and feces (elements such as sodium (Na), zinc (Zn), potassium (K), copper (Cu)), electrical conductivity (EC), the number of years that the farms have been in use, and flock size significantly influence pre-harvest Salmonella prevalence. Egg source, feed type, breed, and manganese (Mn) levels in the soil/feces are other important variables identified to contribute to Salmonella prevalence on larger (≥3 flocks reared per year) farms, while pasture feed and soil carbon-to-nitrogen ratio are predicted to be important for smaller/hobby (<3 flocks reared per year) farms. Predictive models such as the ones described here are important for developing science-based control measures for Salmonella to reduce the environmental, animal, and public health impacts from these types of poultry production systems.

13.
PLoS One ; 17(10): e0268414, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36206262

RESUMEN

BACKGROUND: Malaria remains a major public health challenge in Africa where annually, ~250,000 children with malaria experience a neurologic injury with subsequent neuro-disability. Evidence indicates that a higher temperature during the acute illness is a risk factor for post-infectious neurologic sequelae. As such, aggressive antipyretic therapy may be warranted among children with complicated malaria at substantial risk of brain injury. Previous clinical trials conducted primarily in children with uncomplicated malaria and using only a single antipyretic medication have shown limited benefits in terms of fever reduction; however, no studies to date have examined malaria fever management using dual therapies. In this clinical trial of aggressive antipyretic therapy, children hospitalized with central nervous system (CNS) malaria will be randomized to usual care (acetaminophen every 6 hours for a temperature ≥ 38.5°C) vs. prophylactic acetaminophen and ibuprofen every 6 hours for 72 hours. METHODS: In this double-blinded, placebo controlled, two-armed clinical trial, we will enroll 284 participants from three settings at Queen Elizabeth Central Hospital in Blantyre, Malawi; at the University Teaching Hospitals Children's Hospital in Lusaka, Zambia and at Chipata Central Hospital, Chipata, Zambia. Parents or guardians must provide written informed consent. Eligible participants are 2-11 years with evidence of P. falciparum malaria infection by peripheral blood smear or rapid diagnostic test with CNS symptoms associated with malaria. Eligible children will receive treatment allocation randomization either to standard of care for fever management or to prophylactic, scheduled treatment every 6 hours for 72 hours with dual antipyretic therapies using acetaminophen and ibuprofen. Assignment to treatment groups will be with 1:1 allocation using blocked randomization. The primary outcome will be maximum temperature in the 72 hours after enrolment. Secondary outcomes include parasite clearance as determined by quantitative Histidine Rich Protein II and seizures through 72 hours after enrolment. DISCUSSION: This clinical trial seeks to challenge the practice paradigm of limited fever treatment based upon hyperpyrexia by evaluating the fever-reduction efficacy of more aggressive antipyretic using two antipyretics and prophylactic administration and will elucidate the impact of antipyretics on parasite clearance and acute symptomatic seizures. If aggressive antipyretic therapy is shown to safely reduce the maximum temperature, a clinical trial evaluating the neuroprotective effects of temperature reduction in CNS malaria is warranted.


Asunto(s)
Antipiréticos , Malaria Falciparum , Fármacos Neuroprotectores , Parásitos , Acetaminofén/uso terapéutico , Animales , Antipiréticos/uso terapéutico , Sistema Nervioso Central , Niño , Fiebre/tratamiento farmacológico , Fiebre/prevención & control , Histidina , Humanos , Ibuprofeno/uso terapéutico , Malaria Falciparum/complicaciones , Malaria Falciparum/tratamiento farmacológico , Fármacos Neuroprotectores/uso terapéutico , Ensayos Clínicos Controlados Aleatorios como Asunto , Convulsiones/tratamiento farmacológico , Resultado del Tratamiento , Zambia
14.
Microorganisms ; 10(9)2022 Aug 24.
Artículo en Inglés | MEDLINE | ID: mdl-36144304

RESUMEN

Due to nutritional benefits and perceived humane ways of treating the animals, the demand for antibiotic-free pastured poultry chicken has continued to be steadily rise. Despite the non-usage of antibiotics in pastured poultry broiler production, antibiotic resistance (AR) is reported in zoonotic poultry pathogens. However, factors that drive multidrug resistance (MDR) in pastured poultry are not well understood. In this study, we used machine learning and deep learning approaches to predict farm management practices and physicochemical properties of feces and soil that drive MDR in zoonotic poultry pathogens. Antibiotic use in agroecosystems is known to contribute to resistance. Evaluation of the development of resistance in environments that are free of antibiotics such as the all-natural, antibiotic-free, pastured poultry production systems described here is critical to understand the background AR in the absence of any selection pressure, i.e., basal levels of resistance. We analyzed 1635 preharvest (feces and soil) samples collected from forty-two pastured poultry flocks and eleven farms in the Southeastern United States. CDC National Antimicrobial Resistance Monitoring System guidelines were used to determine antimicrobial/multidrug resistance profiles of Salmonella, Listeria, and Campylobacter. A combination of two traditional machine learning (RandomForest and XGBoost) and three deep learning (Multi-layer Perceptron, Generative Adversarial Network, and Auto-Encoder) approaches identified critical farm management practices and environmental variables that drive multidrug resistance in poultry pathogens in broiler production systems that represents background resistance. This study enumerates management practices that contribute to AR and makes recommendations to potentially mitigate multidrug resistance and the prevalence of Salmonella and Listeria in pastured poultry.

15.
Sci Rep ; 12(1): 11804, 2022 07 12.
Artículo en Inglés | MEDLINE | ID: mdl-35821246

RESUMEN

Polyamines are small cationic molecules that have been linked to various cellular processes including replication, translation, stress response and recently, capsule regulation in Streptococcus pneumoniae (Spn, pneumococcus). Pneumococcal-associated diseases such as pneumonia, meningitis, and sepsis are some of the leading causes of death worldwide and capsule remains the principal virulence factor of this versatile pathogen. α-Difluoromethyl-ornithine (DFMO) is an irreversible inhibitor of the polyamine biosynthesis pathway catalyzed by ornithine decarboxylase and has a long history in modulating cell growth, polyamine levels, and disease outcomes in eukaryotic systems. Recent evidence shows that DFMO can also target arginine decarboxylation. Interestingly, DFMO-treated cells often escape polyamine depletion via increased polyamine uptake from extracellular sources. Here, we examined the potential capsule-crippling ability of DFMO and the possible synergistic effects of the polyamine transport inhibitor, AMXT 1501, on pneumococci. We characterized the changes in pneumococcal metabolites in response to DFMO and AMXT 1501, and also measured the impact of DFMO on amino acid decarboxylase activities. Our findings show that DFMO inhibited pneumococcal polyamine and capsule biosynthesis as well as decarboxylase activities, albeit, at a high concentration. AMXT 1501 at physiologically relevant concentration could inhibit both polyamine and capsule biosynthesis, however, in a serotype-dependent manner. In summary, this study demonstrates the utility of targeting polyamine biosynthesis and transport for pneumococcal capsule inhibition. Since targeting capsule biosynthesis is a promising way for the eradication of the diverse and pathogenic pneumococcal strains, future work will identify small molecules similar to DFMO/AMXT 1501, which act in a serotype-independent manner.


Asunto(s)
Antineoplásicos , Eflornitina , Eflornitina/farmacología , Ornitina Descarboxilasa/metabolismo , Inhibidores de la Ornitina Descarboxilasa , Poliaminas/metabolismo , Streptococcus pneumoniae/metabolismo
16.
Artículo en Inglés | MEDLINE | ID: mdl-35685206

RESUMEN

Background: Emerging critical care systems have gained little attention in low- and middle-income countries. In sub-Saharan Africa, only 4% of the healthcare workforce is trained in critical care, and mortality rates are unacceptably high in this patient population. Objectives: We sought to retrospectively describe the knowledge acquisition and confidence improvement of practitioners who attend the Fundamental Critical Care Support (FCCS) course in Rwanda. Methods: We conducted a retrospective study in which we assessed survey data and multiple-choice question data that were collected before and after course delivery. The purpose of these assessments at the time of delivery was to evaluate participants' perception and acquisition of critical care knowledge. Results: Thirty-six interprofessional clinicians completed the training. Performance on the multiple-choice questions improved overall after the course (mean score pre-course of 56.5% to mean score post-course of 65.8%, p-value <0.001) and improved in all content areas with the exception of diagnosis and management of acute coronary syndrome and acute respiratory failure/mechanical ventilation. Both physicians and nurses improved their scores significantly (68.9% to 75.6%, p-value = 0.031 and 52.0% to 63.5%, p-value <0.001, respectively). Self-reported confidence in level of knowledge also increased in all areas. Survey respondents indicated on open-answer questions that they would like the course offerings at least annually, and that further dissemination of the course in Rwanda was warranted. Conclusion: Deploying the established FCCS course improved Rwandan healthcare provider knowledge and confidence across most critical care content areas. Therefore, this course represents a good first step in bridging the gaps noted in emerging critical care systems. Contributions of the study: Critical care education in sub-Saharan Africa is limited and few staff have formal training. The aim of the study was to determine whether a focused course delivered in Rwanda on critical care management improved knowledge in key areas. Our retrospective study on results from a multiple choice question test and survey indicate that short courses may improve knowledge of critical care management.

17.
IBRO Neurosci Rep ; 12: 271-279, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35746981

RESUMEN

Gliclazide (GLD), a sulphonylurea is efficacious in the treatment of diabetes type-2. However, there is limited information on its activity in the brain, especially in diabetics. This research investigated the brain activities of GLD following streptozotocin-induced diabetes in Wistar rats. Twenty five adult male Wistar rats (200-250 g) were grouped (n = 5) as: Control (distilled water, 5 mL/kg) and GLD (150 mg/kg) groups; and the diabetic groups, untreated streptozotocin (STZ, 35 mg/kg), and STZ (35 mg/kg) treated with GLD (150 mg/kg) for two and four weeks, and already on high fat diet. The animals' body weights and blood glucose levels were checked weekly. After the experimental duration, spontaneous alternation and novel object recognition tests were carried out and the animals sacrificed. Perfusion with phosphate buffered saline preceded brain excision for biochemical analyses, with halves fixed in 10% neutral buffered formalin for histology. Compared with the control, results showed (p < 0.05) declined spontaneous alternation and exploratory activities with no preference for familiar or novel objects, body weights loss, raised blood glucose, increased malondialdehyde with decreased superoxide dismutase concentrations, and no apparent adverse effect on hippocampal and prefrontal cortical Nissl substance in the untreated diabetic group. The adverse observations were attenuated in the GLD treated diabetic groups; although the spontaneous alternation in the four weeks GLD treated diabetic group improved (p < 0.05), exploration of objects increased (p < 0.05) without preference. The present results showed that treatment with GLD for two and four weeks mitigated STZ activities, even though there was less improvement in neurocognitive activities.

18.
Bull World Health Organ ; 100(2): 115-126C, 2022 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-35125536

RESUMEN

OBJECTIVE: To examine changes in vaccination of children younger than 1 year during the coronavirus disease 2019 (COVID-19) pandemic (March 2020-August 2021) in Haiti, Lesotho, Liberia and Malawi. METHODS: We used data from health management information systems on vaccination of children aged 12 months or younger in districts supported by Partners In Health. We used data from January 2016 to February 2020 and a linear model with negative binomial distribution to estimate the expected immunization counts for March 2020-August 2021 with 95% prediction intervals, assuming no pandemic. We compared these expected levels with observed values and estimated the immunization deficits or excesses during the pandemic months. FINDINGS: Baseline vaccination counts varied substantially by country, with Lesotho having the lowest count and Haiti the highest. We observed declines in vaccination administration early in the COVID-19 pandemic in Haiti, Lesotho and Liberia. Continued declines largely corresponded to high rates of COVID-19 infection and discrete stock-outs. By August 2021, vaccination levels had returned to close to or above expected levels in Haiti, Liberia and Lesotho; in Malawi levels remained below expected. CONCLUSION: Patterns of childhood immunization coverage varied by country over the course of the pandemic, with significantly lower than expected vaccination levels seen in one country during subsequent COVID-19 waves. Governments and health-care stakeholders should monitor vaccine coverage closely and consider interventions, such as community outreach, to avoid or combat the disruptions in childhood vaccination.


Asunto(s)
COVID-19 , Niño , Haití/epidemiología , Humanos , Inmunización , Programas de Inmunización , Lactante , Lesotho/epidemiología , Liberia/epidemiología , Malaui/epidemiología , Pandemias , SARS-CoV-2 , Vacunación
20.
Bull. W.H.O. (Online) ; 100(1): 115-126, 2022. figures, tables
Artículo en Inglés | AIM (África) | ID: biblio-1359501

RESUMEN

Objective: To examine changes in vaccination of children younger than 1 year during the coronavirus disease 2019 (COVID-19) pandemic (March 2020-August 2021) in Haiti, Lesotho, Liberia and Malawi. Methods: We used data from health management information systems on vaccination of children aged 12 months or younger in districts supported by Partners In Health. We used data from January 2016 to February 2020 and a linear model with negative binomial distribution to estimate the expected immunization counts for March 2020-August 2021 with 95% prediction intervals, assuming no pandemic. We compared these expected levels with observed values and estimated the immunization deficits or excesses during the pandemic months. Findings: Baseline vaccination counts varied substantially by country, with Lesotho having the lowest count and Haiti the highest. We observed declines in vaccination administration early in the COVID-19 pandemic in Haiti, Lesotho and Liberia. Continued declines largely corresponded to high rates of COVID-19 infection and discrete stock-outs. By August 2021, vaccination levels had returned to close to or above expected levels in Haiti, Liberia and Lesotho; in Malawi levels remained below expected. Conclusion: Patterns of childhood immunization coverage varied by country over the course of the pandemic, with significantly lower than expected vaccination levels seen in one country during subsequent COVID-19 waves. Governments and health-care stakeholders should monitor vaccine coverage closely and consider interventions, such as community outreach, to avoid or combat the disruptions in childhood vaccination.


Asunto(s)
Humanos , Masculino , Femenino , Recién Nacido , Lactante , Preescolar , Niño , Inmunización , Vacunación , Programas de Inmunización , COVID-19 , Pandemias
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...