RESUMO
The presence and localization of plant metabolites are indicative of physiological processes, e.g., under biotic and abiotic stress conditions. Further, the chemical composition of plant parts is related to their quality as food or for medicinal applications. Mass spectrometry imaging (MSI) has become a popular analytical technique for exploring and visualizing the spatial distribution of plant molecules within a tissue. This review provides a summary of mass spectrometry methods used for mapping and identifying metabolites in plant tissues. We present the benefits and the disadvantages of both vacuum and ambient ionization methods, considering direct and indirect approaches. Finally, we discuss the current limitations in annotating and identifying molecules and perspectives for future investigations.
RESUMO
Newborn disease screening increases survival, improves quality of life and reduces treatment costs for healthcare systems. Mass spectrometry (MS) is an effective method for metabolic screening. However, conventional analytical methods require biofluid handling and cooling conditions during transport, making the logistics difficult and expensive, especially for remote regions. 'Paper-spray' (PS) ionization generates a charged solvent spray from samples deposited on paper strips. Therefore, samples can be applied on a suitable matrix and shipped as dried spots to diagnostic laboratories with standard postal or messenger services. We built a robotic platform, the 'Open SprayBot', to automatically analyze paper-deposited samples via PS-MS and increase the sample throughput. The system is operated via RUMBA32 and Arduino Mega boards. A commercial syringe pump and power supply provide solvent application and electrical current required for PS-MS. The usability of the Open SprayBot was demonstrated by quantifying palmitoyl-l-carnitine, a common biomarker in newborn screening.
RESUMO
Increasing evidence hints that DNA hypermethylation may mediate the pathogenic response to cardiovascular risk factors. Here, we tested a corollary of that hypothesis, that is, that the DNA methyltransferase inhibitor decitabine (Dec) ameliorates the metabolic profile of mice fed a moderately high-animal fat and protein diet (HAFPD), a proxy of cardiovascular risk-associated Western-type diet. HAFPD-fed mice were exposed to Dec or vehicle for eight weeks (8W set, 4-32/group). To assess any memory of past exposure to Dec, we surveyed a second mice set treated as 8W but HAFPD-fed for further eight weeks without any Dec (16W set, 4-20/group). In 8W, Dec markedly reduced HAFPD-induced body weight gain in females, but marginally in males. Characterization of females revealed that Dec augmented skeletal muscle lipid content, while decreasing liver fat content and increasing plasma nonesterified fatty acids, adipose insulin resistance, and-although marginally-whole blood acylcarnitines, compared to HAFPD alone. Skeletal muscle mitochondrial DNA copy number was higher in 8W mice exposed to HAFPD and Dec, or in 16W mice fed HAFPD only, relative to 8W mice fed HAFPD only, but Dec induced a transcriptional profile indicative of ameliorated mitochondrial function. Memory of past Dec exposure was tissue-specific and sensitive to both duration of exposure to HAFPD and age. In conclusion, Dec redirected HAFPD-induced lipid accumulation toward the skeletal muscle, likely due to augmented mitochondrial functionality and increased lipid demand. As caveat, Dec induced adipose insulin resistance. Our findings may help identifying strategies for prevention and treatment of lipid dysmetabolism.
Assuntos
Decitabina , Dieta Hiperlipídica , Animais , Camundongos , Dieta Hiperlipídica/efeitos adversos , Feminino , Decitabina/farmacologia , Masculino , Camundongos Endogâmicos C57BL , Proteínas Alimentares/farmacologia , Músculo Esquelético/metabolismo , Músculo Esquelético/efeitos dos fármacos , Metilação de DNA/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Resistência à InsulinaRESUMO
Background: Endemic pemphigus foliaceus and endemic pemphigus vulgaris are autoimmune dermatologic disorders endemic to the Peruvian Amazon. Objective: To determine the ultrastructural skin alterations of three healthy subjects with anti DSG-1 antibodies in areas endemic to pemphigus foliaceus and pemphigus vulgaris in the Peruvian Amazon. Patients and methods: Case series carried out from data of three clinically healthy subjects positive to anti DSG-1 antibodies, from Peru. This study consists of a sub-analysis of data gathered in a previous study. Results: Ultrastructural results are presented from the skin biopsies of three clinically healthy patients positive to anti-desmoglein 1 (DSG-1) antibodies. High Resolution Optical Microscopy (HROM) showed the absence of acantholysis. Transmission Electron Microscopy (TEM) showed the widening of intercellular space between keratinocytes, the presence of vacuoles in intercellular space with granular material and cytoplasmic vacuolization, loss of desmosome structure, loss of normal distribution among tonofilaments and lateral separation among cells in the stratum basale. Conclusion: According to our results, healthy subjects that present anti-desmoglein 1 antibodies can develop ultrastructural alterations that are visible through transmission electron microscopy but not through conventional optical microscopy.
RESUMO
RATIONALE: Ambient ionization mass spectrometry (AIMS) delivers realistic data from samples in their native state. In addition, AIMS methods reduce time and costs for sample preparation and have less environmental impact. However, AIMS data are often complex and require substantial processing before interpretation. METHODS: We developed an interactive R script for guided mass spectrometry (MS) data processing. The "MQ_Assistant" is based on MALDIquant, a popular R package for MS data processing. In each step, the user can try and preview the effect of chosen parameters before deciding on the values with the best result and proceeding to the next stage. The outcome of the MQ_Assistant is a feature matrix that can be further analyzed in R and statistics tools such as MetaboAnalyst. RESULTS: Using 360 AIMS example spectra, we demonstrate the step-by-step processing for creating a feature matrix. In addition, we show how to visualize the results of three biological replicates of a plant-microbe interaction between Arabidopsis and Trichoderma as a heatmap using R and upload them to MetaboAnalyst. The final parameter set can be saved for reuse in MALDIquant workflows of similar data. CONCLUSIONS: The MQ_Assistant helps novices and experienced users to develop workflows for (AI)MS data processing. The interactive procedure supports the quick finding of appropriate settings. These parameters can be exported and reused in future projects. The stepwise operation with visual feedback also suggests the use of the MQ_Assistant in education.
RESUMO
Genetic counseling and testing (GCT) inform cancer management for persons at risk for hereditary breast and ovarian cancer (HBOC). Community-based organizations (CBOs) may play a role in identifying at-risk Latinx individuals to connect them to GCT but data are lacking. Two academic centers and their four CBO partners planned to implement a validated questionnaire for HBOC risk screening ("HBOC risk screening tool"). This study aimed to assess CBO's preferences for HBOC risk screening tools, as well as the barriers and facilitators anticipated for future implementation. Pre-implementation focus groups were conducted with CBO's staff. Discussions centered on current practices to identify and refer at-risk patients. During the discussion, staff were asked to select one out of five validated HBOC risk screening tools to implement and to discuss anticipated barriers/facilitators for implementation. The four focus groups were coded and qualitative analyzed following the Consolidated Framework for Implementation Research (CFIR) and Health Equity domains. All CBOs chose the Family History Screen 7 (FHS-7). Participants (N = 35) highlighted how the FHS-7 was easy to adapt to better fit the target population and changing guidelines. They had positive attitudes toward implementing the screening tool, stressed how the culture of the organization positioned them to reach the target population, and noted barriers in different CFIR domains (e.g., low knowledge about HBOC and GCT referrals; scarce available resources). Participants pointed to barriers related to health equity domains including limited access to GCT and follow-up care for uninsured and underinsured populations, challenges obtaining accurate family history, and immigration-related barriers. CBOs highlighted the importance of partnering with other stakeholders to overcome barriers. Findings emphasize the need to develop multi-level implementation strategies to overcome barriers and leverage facilitators. This study can inform the development of implementation toolkits for CBOs to implement HBOC screening tools to advance health equity.
Assuntos
Neoplasias da Mama , Equidade em Saúde , Neoplasias Ovarianas , Humanos , Feminino , Detecção Precoce de Câncer , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/genética , Pesquisa Qualitativa , Neoplasias Ovarianas/diagnóstico , Neoplasias Ovarianas/genéticaRESUMO
Hepatic fibrosis is caused by chronic injury due to toxic, infectious, or metabolic causes, and it may progress to cirrhosis and hepatocellular carcinoma. There is currently no antifibrotic therapy authorized for human use; however, there are promising studies using cell therapies. There are also no animal models that exactly reproduce human liver fibrosis that can be used to better understand the mechanisms of its regression and identify new targets for treatment and therapeutic approaches. On the other hand, mesenchymal stem cells (MSC) have experimentally demonstrated fibrosis regression effects, but it is necessary to have an animal model of advanced liver fibrosis to evaluate the effect of these cells. The aim of this work was to establish a protocol for the induction of advanced liver fibrosis in rats using thioacetamide (TAA), which will allow us to perform trials using MSC as a possible therapy for fibrosis regression. For this purpose, we selected 24 female rats and grouped them into three experimental groups: the control group (G-I) without treatment and groups II (G-II) and III (G-III) that received TAA by intraperitoneal injection for 24 weeks. Then, 1 × 106/kg adipose mesenchymal stem cells (ASCs) were infused intravenously. Groups G-I and G-II were sacrificed 7 days after the last dose of ASC, and G-III was sacrificed 8 weeks after the last ASC infusion, all with xylazine/ketamine (40 mg/kg). The protocol used in this work established a model of advanced hepatic fibrosis as corroborated by METAVIR tests of the histological lesions; by the high levels of the markers α-SMA, CD68, and collagen type I; by functional alterations due to elevated markers of the hepatic lesions; and by alterations of the leukocytes, lymphocytes, and platelets. Finally, transplanted cells in the fibrous liver were detected. We conclude that TAA applied using the protocol introduced in this study induces a good model of advanced liver fibrosis in rats.
Assuntos
Células-Tronco Mesenquimais , Tioacetamida , Humanos , Ratos , Feminino , Animais , Tioacetamida/toxicidade , Cirrose Hepática/induzido quimicamente , Cirrose Hepática/terapia , Modelos Animais de Doenças , Células-Tronco Mesenquimais/metabolismoRESUMO
Background and Aim: Ribonucleic acid viruses remain latent in different cell types, including mesenchymal stem cells; however, the distemper virus remains undetected in these cells. This study aimed to determine whether adipose stem cells (ASCs) from dogs with distemper disease are infected with the canine morbillivirus (CM). Materials and Methods: Twelve dogs with the neurological phase of the disease and who were positive for CM by reverse transcription polymerase chain reaction (RT-PCR), were studied. ASCs from adipose tissue of the lesser omentum of these infected dogs were isolated and characterized. Direct fluorescence was used to detect the viral antigen in cell cultures. Flow cytometry and RT-PCR identified detectable quantities of the virus in two cultures, while electron microscopy confirmed the CM particles within ASCs. Results: This study revealed that ASCs of the omentum of dogs with distemper disease can be infected with CM, indicating their possible involvement in this virus latency and persistence. This suggests that its detection should be considered within the quality control process of stem cells intended for regenerative medicine. Conclusion: To the best of our knowledge, this is the first study that demonstrates that omentum ASCs from dogs with distemper disease can be infected with CM and may be involved in viral latency or persistence. Our study also suggests that the detection of CM should be considered within the quality control process of stem cells intended for regenerative medicine.
RESUMO
The localization of metabolites in plant tissues is often related to their biological function and biosynthesis. Mass spectrometry imaging (MSI) provides comprehensive information about the distribution of known and unknown compounds in tissues. In this protocol, we describe the use of laser desorption low-temperature plasma (LD-LTP) ionization MSI. This technology enables the direct analysis of native tissues under ambient conditions.
Assuntos
Lasers , Plantas , Temperatura Baixa , Espectrometria de Massas/métodos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , TemperaturaRESUMO
Ambient ionisation mass spectrometry (AIMS) enables studying biological systems in their native state and direct high-throughput analyses. The ionisation occurs in the physical conditions of the surrounding environment. Simple spray or plasma-based AIMS devices allow the desorption and ionisation of molecules from solid, liquid and gaseous samples. 3D printing helps to implement new ideas and concepts in AIMS quickly. Here, we present examples of 3D printed AIMS sources and devices for ion transfer and manipulation. Further, we show the use of 3D printer parts for building custom AIMS sampling robots and imaging systems. Using 3D printing technology allows upgrading existing mass spectrometers with relatively low cost and effort.
RESUMO
INTRODUCTION: We aimed to search the literature for global surgical curricula, assess if published resources align with existing competency frameworks in global health and surgical education, and determine if there is consensus around a fundamental set of competencies for the developing field of academic global surgery. METHODS: We reviewed SciVerse SCOPUS, PubMed, African Medicus Index, African Journals Online (AJOL), SciELO, Latin American and Caribbean Health Sciences Literature (LILACS) and Bioline for manuscripts on global surgery curricula and evaluated the results using existing competency frameworks in global health and surgical education from Consortium of the Universities for Global Health (CUGH) and Accreditation Council for Graduate Medical Education (ACGME) professional competencies. RESULTS: Our search generated 250 publications, of which 18 were eligible: (1) a total of 10 reported existing competency-based curricula that were concurrent with international experiences, (2) two reported existing pre-departure competency-based curricula, (3) six proposed theoretical competency-based curricula for future global surgery education. All, but one, were based in high-income countries (HICs) and focused on the needs of HIC trainees. None met all 17 competencies, none cited the CUGH competency on "Health Equity and Social Justice" and only one mentioned "Social and Environmental Determinants of Health." Only 22% (n = 4) were available as open-access. CONCLUSION: Currently, there is no universally accepted set of competencies on the fundamentals of academic global surgery. Existing literature are predominantly by and for HIC institutions and trainees. Current frameworks are inadequate for this emerging academic field. The field needs competencies with explicit input from LMIC experts to ensure creation of educational resources that are accessible and relevant to trainees from around the world.
Assuntos
Currículo , Educação de Pós-Graduação em Medicina , Acreditação , Competência Clínica , Saúde GlobalRESUMO
Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a major threat to public health. Rapid molecular testing for convenient and timely diagnosis of SARS-CoV-2 infections represents a challenge that could help to control the current pandemic and prevent future outbreaks. We aimed to develop and validate a multiplex and colorimetric reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay using lyophilized LAMP reagents for sensitive and rapid detection of SARS-CoV-2. LAMP primers were designed for a set of gene targets identified by a genome-wide comparison of viruses. Primer sets that showed optimal features were combined into a multiplex RT-LAMP assay. Analytical validation included assessment of the limit of detection (LoD), intra- and inter-assay precision, and cross-reaction with other respiratory pathogens. Clinical performance compared to that of real-time reverse transcriptase-polymerase chain reaction (RT-qPCR) was assessed using 278 clinical RNA samples isolated from swabs collected from individuals tested for COVID-19. The RT-LAMP assay targeting the RNA-dependent RNA polymerase (RdRp), membrane (M), and ORF1ab genes achieved a comparable LoD (0.65 PFU/mL, CT=34.12) to RT-qPCR and was 10-fold more sensitive than RT-qPCR at detecting viral RNA in clinical samples. Cross-reactivity to other respiratory pathogens was not observed. The multiplex RT-LAMP assay demonstrated a strong robustness and acceptable intra- and inter-assay precision (mean coefficient of variation, 4.75% and 8.30%). Diagnostic sensitivity and specificity values were 100.0% (95% CI: 97.4-100.0%) and 98.6% (95% CI: 94.9-99.8%), respectively, showing high consistency (Cohen's kappa, 0.986; 95% CI: 0.966-1.000; p<0.0001) compared to RT-qPCR. The novel one-step multiplex RT-LAMP assay is storable at room temperature and showed similar diagnostic accuracy to conventional RT-qPCR, while being faster (<45 min), simpler, and cheaper. The new assay could allow reliable and early diagnosis of SARS-CoV-2 infections in primary health care. It may aid large-scale testing in resource-limited settings, especially if it is integrated into a point-of-care diagnostic device.
Assuntos
COVID-19 , SARS-CoV-2 , Teste para COVID-19 , Técnicas de Laboratório Clínico , Colorimetria , Humanos , Técnicas de Diagnóstico Molecular , Técnicas de Amplificação de Ácido Nucleico , RNA Viral/genética , Transcrição Reversa , Sensibilidade e EspecificidadeRESUMO
Triple-negative breast tumours (TNBTs) make up 15-20% of all breast tumours. There is no treatment for them, and the role that cancer stem cells (CSCs) have in carcinogenesis is still unclear, so finding markers and therapeutic targets in CSC exosomes requires these cells to exist as a homogeneous cell population. The objective of this work was to determine differences in ultrastructural morphology, proliferative capacity, and mouse-xenotransplantation characteristics of the MDA-MB-231 and MDA-MB-436 TNBT cell lines with the CD44 high /CD24 low phenotype in order to study their exosomes. The results show that the CD44 high /CD24 low MBA-MB-231 cells had a population doubling time of 41.56 h, compared to 44.79 h in the MDA-MB-436 cell line. After magnetic immunoseparation, 18.75% and 14.56% of the stem cell population of the MDA-MB-231 and MDA-MB-436 cell lines, respectively, were of the CD44 high /CD24 low phenotype, which were expanded to reach purities of 80.4% and 87.6%. The same expanded lineage in both cell lines was shown to possess the pluripotency markers Nanog and Oct4. Under a scanning electron microscope, the CD44 high /CD24 low lineage of the MBA-MD-231 cell line formed groups of more interconnected cells than this lineage of the MBA-MD-436 line. A total of 16% of the mice inoculated with the CD44 high /CD24 low lineage of either cell line presented tumours of the breast, lung, and submandibular ganglia, in whose tissues variable numbers of inoculated cells were found 30 days post-inoculation. By magnetic immunoselection, it was possible to isolate in similar quantities and characterize, expand, and xenotransplant the CD44 high /CD24 low lineage of the MDA-MB-231 and MDA-MB-436 cell lines. The former cell line has greater proliferative capacity, the two lines differ under scanning electron microscopy in how they intercommunicate, and both cell lines induce new tumours in mice and persist at least 30 days post-inoculation in the transplanted animal so their exosomes would also be different.
RESUMO
Peru has become one of the countries with the highest mortality rates from the current coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). To investigate early transmission events and the genomic diversity of SARS-CoV-2 isolates circulating in Peru in the early COVID-19 pandemic, we analyzed 3472 viral genomes, of which 149 were from Peru. Phylogenomic analysis revealed multiple and independent introductions of the virus likely from Europe and Asia and a high diversity of genetic lineages circulating in Peru. In addition, we found evidence for community-driven transmission of SARS-CoV-2 as suggested by clusters of related viruses found in patients living in different regions of Peru.
Assuntos
COVID-19/epidemiologia , COVID-19/transmissão , SARS-CoV-2/genética , COVID-19/virologia , Variação Genética , Genoma Viral/genética , Humanos , Peru/epidemiologia , Filogenia , Filogeografia , RNA Viral/genética , SARS-CoV-2/classificaçãoRESUMO
TiO2 nanoparticles were synthesized by green chemistry where organic solvents are replaced by an aqueous extract solution of lemongrass leaves that act as a reducer and growth-stopper agent. The nanoparticles were codoped with N-Fe to modify the absorption range in the electromagnetic spectrum and were characterized by Fourier-transform infrared (FTIR), scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS), and UV-vis/diffuse reflectance spectroscopy (DRS). The modified samples with Fe and N resulted in smaller nanoparticle size values than pure TiO2. Similarly, the band-gap energy for doped nanoparticles decreased to 2.22 eV in relation to the value of 3.09 eV for pure TiO2, due to the introduction of new energy levels.
RESUMO
BACKGROUND: Increasing access to safe, timely, and affordable acute care in low- and middle-income countries is a worldwide priority. Longitudinal curricula on systems of acute care have not been previously described. OBJECTIVES: The authors aimed to develop a novel four-year longitudinal curriculum for medical students addressing systems development across multiple acute care specialties. METHODS: The authors followed Kern's six-step framework for curriculum design. After review of literature, a group of medical students and school of medicine faculty conducted a targeted needs assessment. Foundational goals and objectives were adapted from the 39 interprofessional global health competencies by the Consortium of Universities for Global Health. Educational strategies include didactic sessions, workshops, journal clubs, preceptorships, and community outreach. Clinical years include specialty-specific emphases, guided junior-level discussions, and a capstone project. Yearly SWOT and Kirkpatrick model analyses served as program evaluation. FINDINGS: The Curriculum Council approved the program in July 2019. During the first cycle, the program matriculated 30 students from classes of 2023 (14) and 2022 (16). The first year produced 11 interactive sessions, 6 journal clubs, and 10 seminars led by 31 faculty and guest speakers; 29/30 students completed requirements; 87 evaluations reflected 4.57/5 content satisfaction and 4.73/5 instructor satisfaction. The 2023 cohort reported improved understanding of session objectives (3.13/5 vs. 3.82/5, p = 0.03). Free-text feedback led to implementation of pre-reading standardization and activity outlines. CONCLUSION: The Program was well-received and successfully implemented. It meets the needs of graduating medical students interested in leading global health work. This novel student-faculty collaborative model could be applied at other institutions seeking to provide students with a foundation in global acute care.