RESUMO
The carbon-free chemical storage and release of renewable energy is an important task to drastically reduce CO2 emissions. The high specific energy density of iron and its recyclability makes it a promising storage material. Energy release by oxidation with air can be realized by the combustion of micron-sized iron powders in retro-fitted coal fired power plants and in fixed-bed reactors under milder conditions. An experimental parameter study of iron powder oxidation with air was conducted based on thermogravimetric analysis in combination with wide-angle X-ray scattering and Mössbauer spectroscopy. In agreement with literature the oxidation was found to consist of a very fast initial oxidation of the outer particle layer followed by much slower oxidation due to diffusion of iron ions through the Fe2O3/Fe3O4 layer being the rate-limiting step. Scanning electron microscopy analysis of the iron particle before and after oxidation reveal a strong particle morphology transformation. This impact on the reaction was studied by cyclization experiments. Up to 10 oxidation-reduction cycles show that both, oxidation and reduction rates, increase strongly with cycling due to increased porosity.
RESUMO
In the current work, the rational synthesis of trinuclear copper complexes, incorporating acute bite angle POP- and PSP-type ligands, is reported. The in situ formation of POP (Ph2P-O-PPh2) or PSP (Ph2P-S-PPh2) ligands in the presence of a copper(I) precursor gave access to various trinuclear copper complexes of the form [Cu3(µ3-Hal)2(µ-PXP)3]PF6 [X = O; Hal = Cl (1), Br (2), I (3) and X = S; Hal = Cl (5), Br (6), I (7)]. Related iodide-containing complexes and clusters, such as [Cu4(µ3-I)4(Ph2PI)4] (4) and [Cu3(µ3-I)2(µ-I)(µ-PSP)2] (8), could also be obtained via the variation of the reaction stoichiometry. The investigation of the photo-optical properties by photo-luminescence spectroscopy has demonstrated that the phosphorescence in the visible region can be switched off through the mere change of the heteroatom in the ligand backbone (POP vs PSP ligand scaffold). Theoretical studies have been conducted to complement the experimental photo-optical data with detailed insights into the occurring electronic transitions. Consequently, this systematic study paves the way for tuning the photo-optical properties of transition metal complexes in a more rational way.
RESUMO
Premise: The agar-based culture of Arabidopsis seedlings is widely used for quantifying root traits. Shoot traits are generally overlooked in these studies, probably because the rosettes are often askew. A technique to assess the shoot surface area of seedlings grown inside agar culture dishes would facilitate simultaneous root and shoot phenotyping. Methods: We developed an image processing workflow in Python that estimates rosette area of Arabidopsis seedlings on agar culture dishes. We validated this method by comparing its output with other metrics of seedling growth. As part of a larger study on genetic variation in plant responses to nitrogen form and concentration, we measured the rosette areas from more than 2000 plate images. Results: The rosette area measured from plate images was strongly correlated with the rosette area measured from directly overhead and moderately correlated with seedling mass. Rosette area in the large image set was significantly influenced by genotype and nitrogen treatment. The broad-sense heritability of leaf area measured using this method was 0.28. Discussion: These results indicated that this approach for estimating rosette area produces accurate shoot phenotype data. It can be used with image sets for which other methods of leaf area quantification prove unsuitable.
RESUMO
Nitrogen is an essential element required for plant growth and productivity. Understanding the mechanisms and natural genetic variation underlying nitrogen use in plants will facilitate the engineering of plant nitrogen use to maximize crop productivity while minimizing environmental costs. To understand the scope of natural variation that may influence nitrogen use, we grew 1,135 Arabidopsis thaliana natural genotypes on two nitrogen sources, nitrate and ammonium, and measured both developmental and defense metabolite traits. By using different environments and focusing on multiple traits, we identified a wide array of different nitrogen responses. These responses are associated with numerous genes, most of which were not previously associated with nitrogen responses. Only a small portion of these genes appear to be shared between environments or traits, while most are predominantly specific to a developmental or defense trait under a specific nitrogen source. Finally, by using a large population, we were able to identify unique nitrogen responses, such as preferring ammonium or nitrate, which appear to be generated by combinations of loci rather than a few large-effect loci. This suggests that it may be possible to obtain novel phenotypes in complex nitrogen responses by manipulating sets of genes with small effects rather than solely focusing on large-effect single gene manipulations.
Assuntos
Compostos de Amônio , Arabidopsis , Arabidopsis/metabolismo , Nitratos/farmacologia , Nitratos/metabolismo , Compostos de Amônio/metabolismo , Raízes de Plantas/metabolismo , Nitrogênio/metabolismo , Variação GenéticaRESUMO
Premise: High-precision data acquisition (DAQ) is essential for developing new methods in the plant sciences. Commercial high-resolution DAQ systems are cost prohibitive, whereas the less expensive systems that are currently available lack the resolution and precision required for many physiological measurements. Methods and Results: We developed the software libraries, called piadcs, and hardware design for a DAQ system based on an ultra-high-resolution analog-to-digital converter and a Raspberry Pi computer. We tested the system precision with and without a thermocouple attached and found the precision with the sensor to be better than ±0.01°C and the maximum possible system resolution to be 0.4 ppm. Conclusions: The ultra-high-resolution DAQ system described here is inexpensive, flexible enough to be used with many different sensors, and can be built by researchers with rudimentary electronic and computer skills. This system is most applicable in the development of new measurement techniques and the improvement of existing methods.
RESUMO
The objective of the review is to present recent updates on anaphylaxis in paediatric population worldwide. The article summarizes the results of epidemiological studies, diagnostic methods and treatments. We present a new WAO definition of anaphylaxis (2019), which broader criteria excluding dermal symptoms should facilitate faster life-saving adrenaline use. Adrenaline remains the best treatment to manage severe symptoms and to prevent biphasic reactions. There is ongoing effort to increase adrenaline use, such as modified autoinjectors, individual training, and diversified dosing. There are five independent risk factors of lethal anaphylaxis in children, including history of asthma, almost immediate onset of symptoms, unwell appearance, tachycardia and hypotension. We also report improvements in diagnostics, like component-resolved diagnostics, and novel therapies stimulating immunotolerance. We signal the development of ICD-11 with updated coding of anaphylaxis, which corresponds better to clinical observations.
RESUMO
This is the first report of the concurrent development of long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency (LCHADD) and Crigler-Najjar syndrome type 1 (CNs1) inherited via uniparental disomy of chromosome 2, which are both autosomal recessive pathologies. Through an expanded newborn metabolic panel, a male infant was identified as having an acylcarnitine pattern typical for LCHADD, later confirmed to be caused by a well-characterized pathogenic variant in the HADHA gene located at 2p23. Prolonged non-hematologic jaundice requiring repetitive phototherapy prompted further genetic analysis, leading to the identification of another genetic abnormality consistent with CNs1, which was caused by a novel pathogenic variant in the UGT1A1 gene located at 2q37. The two identified point mutations in chromosome 2 were homozygous and present on separate arms, which indicated potential uniparental disomy. Microarray analysis of the genetic material from the patient and his parents confirmed paternal isodisomy of chromosome 2. Further studies are needed to identify other possible pathogenic variants located on the same defective chromosome, evaluate the combined effect of the two metabolic abnormalities, and plan the best possible treatment and care.
Assuntos
Síndrome de Crigler-Najjar , Cardiomiopatias , Cromossomos Humanos Par 2/genética , Síndrome de Crigler-Najjar/genética , Humanos , Lactente , Recém-Nascido , Erros Inatos do Metabolismo Lipídico , Masculino , Miopatias Mitocondriais , Proteína Mitocondrial Trifuncional/deficiência , Doenças do Sistema Nervoso , Rabdomiólise , Dissomia Uniparental/genéticaRESUMO
Chloroplast movement in leaves has been shown to help minimize photoinhibition and increase growth under certain conditions. Much can be learned about chloroplast movement by studying the chloroplast positioning in leaves using e.g., confocal fluorescence microscopy, but access to this type of microscopy is limited. This protocol describes a method that uses the changes in leaf transmission as a proxy for chloroplast movement. If chloroplasts are spread out in order to maximize light interception, the transmission will be low. If chloroplasts move towards the anticlinal cell walls to avoid light, the transmission will be higher. This protocol describes how to use a straightforward, home-built instrument to expose leaves to different blue light intensities and quantify the dynamic changes in leaf transmission. This approach allows researchers to quantitatively describe chloroplast movement in different species and mutants, study the effects of chemicals and environmental factors on it, or screen for novel mutants e.g., to identify missing components in the process that leads from light perception to the movement of chloroplasts.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Cloroplastos , Luz , Movimento , Folhas de PlantaRESUMO
BACKGROUND: The long-term impact of extreme prematurity on cardiac structure and function has not been fully evaluated. AIMS: The aim of the study was to assess cardiac condition at 11 years of age in a local cohort of extremely low birth weight (ELBW) children born between 2002 and 2004 and to compare it to a previous study in the same group at 7 years of age. METHODS: Sixty-four children with ELBW (median birth weight of 890 g) and 36 children born at full term underwent echocardiography and physical examination. RESULTS: M-mode echocardiography parameters, expressed as z-scores for body surface area (mean [SD]), showed significant differences in left ventricular end-diastolic dimension (-1.01 [0.91] vs 0.35 [0.71]; P < 0.001), left ventricular end-systolic dimension (-0.29 [0.92] vs 0.57 [0.65]; P < 0.001), aorta dimension (0.63 [1.14] vs 1.63 [1.30]; P < 0.001), and left atrial dimension (-1.75 [0.97] vs -0.01 [0.86]; P < 0.001) between the study group and controls at 11 years of age. Fractional shortening (FS) and ejection fraction (EF) were higher in the ELBW children than in their full-term counterparts (33.6 [5.5] vs 30.8 [4.34]; P = 0.009 and 0.63 [0.07] vs 0.58 [0.06]; P = 0.005, respectively) at a mean age of 11 years. CONCLUSIONS: The ELBW children had smaller hearts than full-term controls at both 7 and 11 years of age. The FS and EF were elevated in the group of 11-year-old ELBW children. We observed comparable progress in cardiac growth (approximately 20%) in premature and full-term children over a 4-year study period.
Assuntos
Cardiopatias , Recém-Nascido de Peso Extremamente Baixo ao Nascer , Criança , Estudos de Coortes , Ecocardiografia , Coração , Humanos , Recém-NascidoRESUMO
Histomorphological and functional alterations in pancreatic islet composition directly correlate with hyperglycemia severity. Progressive deterioration of metabolic control in subjects suffering from type 2 diabetes is predominantly caused by impaired beta-cell functionality. The glutaredoxin system is supposed to wield protective properties for beta-cells. Therefore, we sought to identify a correlation between the structural changes observed in diabetic pancreatic islets with altered glutaredoxin 5 expression, in order to determine an underlying mechanism of beta-cell impairment. Islets of db/db mice presenting with uncontrolled diabetes were assessed in terms of morphological structure and insulin, glucagon, and glutaredoxin 5 expression. MIN6 cell function and glutaredoxin 5 expression were analyzed after exposure to oleic acid and hypoxia. Islets of diabese mice were marked by typical remodeling and distinct reduction of, and shifts, in localization of glutaredoxin 5-positive cells. These islets featured decreased glutaredoxin 5 as well as insulin and glucagon content. In beta-cell culture, glutaredoxin 5 protein and mRNA expression were decreased by hypoxia and oleic acid but not by leptin treatment. Our study demonstrates that glutaredoxin 5 expression patterns are distinctively altered in islets of rodents presenting with uncontrolled diabesity. In vitro, reduction of islet-cell glutaredoxin 5 expression was mediated by hypoxia and oleic acid. Thus, glutaredoxin 5-deficiency in islets during diabetes may be caused by lipotoxicity and hypoxia.
RESUMO
BACKGROUND: Early initiation of combination antiretroviral therapy (cART) for HIV-positive pregnant women can decrease vertical transmission to less than 5%. Programmatic barriers to early cART include decentralized care, disease-stage assessment delays, and loss to follow-up. INTERVENTION: Our intervention had 3 components: integrated HIV and antenatal services in 1 location with 1 provider, laboratory courier to expedite CD4 counts, and community-based follow-up of women-infant pairs to improve prevention of mother-to-child transmission attendance. Preintervention HIV-positive pregnant women were referred to HIV clinics for disease-stage assessment and cART initiation for advanced disease (CD4 count <350 cells/µL or WHO stage >2). METHODS: We used a quasi-experimental design with preintervention/postintervention evaluations at 6 government antenatal clinics (ANCs) in Southern Province, Zambia. Retrospective clinical data were collected from clinic registers during a 7-month baseline period. Postintervention data were collected from all antiretroviral therapy-naive, HIV-positive pregnant women and their infants presenting to ANC from December 2011 to June 2013. RESULTS: Data from 510 baseline women-infant pairs were analyzed and 624 pregnant women were enrolled during the intervention period. The proportion of HIV-positive pregnant women receiving CD4 counts increased from 50.6% to 77.2% [relative risk (RR) = 1.81; 95% confidence interval (CI): 1.57 to 2.08; P < 0.01]. The proportion of cART-eligible pregnant women initiated on cART increased from 27.5% to 71.5% (RR = 2.25; 95% CI: 1.78 to 2.83; P < 0.01). The proportion of eligible HIV-exposed infants with documented 6-week HIV PCR test increased from 41.9% to 55.8% (RR = 1.33; 95% CI: 1.18 to 1.51; P < 0.01). CONCLUSIONS: Integration of HIV care into ANC and community-based support improved uptake of CD4 counts, proportion of cART-eligible women initiated on cART, and infants tested.
Assuntos
Antirretrovirais/uso terapêutico , Infecções por HIV/tratamento farmacológico , Infecções por HIV/transmissão , Transmissão Vertical de Doenças Infecciosas/prevenção & controle , Adesão à Medicação , Complicações Infecciosas na Gravidez/tratamento farmacológico , Cuidado Pré-Natal/organização & administração , Adulto , Estudos de Coortes , Estudos Controlados Antes e Depois , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Gravidez , Cuidado Pré-Natal/métodos , Estudos Retrospectivos , Adulto Jovem , ZâmbiaRESUMO
OBJECTIVE: To evaluate the impact of rapid syphilis tests (RSTs) on syphilis testing and treatment in pregnant women in Kalomo District, Zambia. METHODS: In March 2012, health workers at all 35 health facilities in Kalomo Distract were trained in RST use and penicillin treatment. In March 2013, data were retrospectively abstracted from 18 randomly selected health facilities and stratified into three time intervals: baseline (6months prior to RST introduction), midline (0-6 months after RST introduction), and endline (7-12 months after RST introduction). RESULTS: Data collected on 4154 pregnant women showed a syphilis-reactive seroprevalence of 2.7%. The proportion of women screened improved from baseline (140/1365, 10.6%) to midline (976/1446, 67.5%), finally decreasing at endline (752/1337, 56.3%) (P<0.001). There was no significant difference in the proportion of syphilis-seroreactive pregnant women who received 1 dose of penicillin before (1/2, 50%) or after (5/48, 10.4%; P=0.199) RST introduction with low treatment rates throughout. CONCLUSION: With RST scale-up in Zambia and other resource-limited settings, same-day test and treatment with penicillin should be prioritized to achieve the goal of eliminating congenital syphilis.
Assuntos
Avaliação do Impacto na Saúde/estatística & dados numéricos , Programas de Rastreamento/estatística & dados numéricos , Complicações Infecciosas na Gravidez/diagnóstico , Diagnóstico Pré-Natal/estatística & dados numéricos , Sífilis/diagnóstico , Adulto , Feminino , Humanos , Programas de Rastreamento/métodos , Penicilinas/uso terapêutico , Gravidez , Complicações Infecciosas na Gravidez/tratamento farmacológico , Diagnóstico Pré-Natal/métodos , Estudos Retrospectivos , Sífilis/tratamento farmacológico , Fatores de Tempo , ZâmbiaRESUMO
BACKGROUND: Neonatal sepsis is a major cause of neonatal mortality. In populations with limited access to health care, early identification of bacterial infections and initiation of antibiotics by community health workers (CHWs) could be lifesaving. It is unknown whether this strategy would be feasible using traditional birth attendants (TBAs), a cadre of CHWs who typically have limited training and educational backgrounds. METHODS: We analyzed data from the intervention arm of a cluster-randomized trial involving TBAs in Lufwanyama District, Zambia, from June 2006 to November 2008. TBAs followed neonates for signs of potential infection through 28 days of life. If any of 16 criteria were met, TBAs administered oral amoxicillin and facilitated referral to a rural health center. RESULTS: Our analysis included 1,889 neonates with final vital status by day 28. TBAs conducted a median of 2 (interquartile range 2-6) home visits (51.4% in week 1 and 48.2% in weeks 2-4) and referred 208 neonates (11%) for suspected sepsis. Of referred neonates, 176/208 (84.6%) completed their referral. Among neonates given amoxicillin, 171/183 (93.4%) were referred; among referred neonates, 171/208 (82.2%) received amoxicillin. Referral and/or initiation of antibiotics were strongly associated with neonatal death (for referral, relative risk [RR]â=â7.93, 95% confidence interval [CI]â=â4.4-14.3; for amoxicillin administration, RRâ=â4.7, 95% CIâ=â2.4-8.7). Neonates clinically judged to be "extremely sick" by the referring TBA were at greatest risk of death (RRâ=â8.61, 95% CIâ=â4.0-18.5). CONCLUSION: The strategy of administering a first dose of antibiotics and referring based solely on the clinical evaluation of a TBA is feasible and could be effective in reducing neonatal mortality in remote rural settings.
Assuntos
Amoxicilina/uso terapêutico , Antibacterianos/uso terapêutico , Infecções Bacterianas/tratamento farmacológico , Competência Clínica/normas , Doenças do Recém-Nascido/tratamento farmacológico , Tocologia/educação , Sepse/tratamento farmacológico , Infecções Bacterianas/mortalidade , Competência Clínica/estatística & dados numéricos , Análise por Conglomerados , Parto Obstétrico/educação , Parto Obstétrico/estatística & dados numéricos , Feminino , Humanos , Lactente , Mortalidade Infantil , Recém-Nascido , Doenças do Recém-Nascido/mortalidade , Masculino , Tocologia/normas , Gravidez , Encaminhamento e Consulta/normas , Encaminhamento e Consulta/estatística & dados numéricos , População Rural , Sepse/mortalidade , Zâmbia/epidemiologiaRESUMO
The expression of apoptosis genes in a commercial pre-designed low-density array from Applied Biosystems was evaluated in two human brain cancer cell models, LN-18 and Daoy (HTB-186™) in comparison to the reference human primary endothelial cells under basic conditions. Analysis of the gene expression in the cancer cell lines compared to the normal control revealed features reflecting anti-apoptotic and inflammatory characteristics of the former. There was an overall downregulation of apoptosis-stimulating genes in both cancer cell lines, along with an upregulation of certain apoptosis inhibitors. A number of genes demonstrated statistically significant changes in their expressions, including BAX (BCL2-associated X protein); the CARD4/NLR family, CARD domain containing 4; CASP10 (caspase 10, apoptosis-related cysteine peptidase); DAP1 (death-associated protein kinase 1), and BIRC5 (baculoviral IAP repeat-containing 5). Anti-apoptotic potential in both cell lines was demonstrated by changes in the Bax:Bcl-2 ratio and downregulation of the APAF1 gene in LN18 cells. There was also significant downregulation of extrinsic signals and the TNF/FADD/inflammatory cascade, and upregulation of caspase inhibitors (IAPs). These results provided a novel molecular characterization of important human cancer cell lines, which might provide a useful research tool for investigating the experimental model of the CNS cell.
Assuntos
Apoptose/genética , Regulação para Baixo/genética , Glioblastoma/genética , Glioblastoma/patologia , Meduloblastoma/genética , Meduloblastoma/patologia , Regulação para Cima/genética , Proteínas Reguladoras de Apoptose/genética , Fator Apoptótico 1 Ativador de Proteases/genética , Caspase 10/genética , Linhagem Celular Tumoral , Proteína de Domínio de Morte Associada a Fas/genética , Humanos , Proteínas Inibidoras de Apoptose/genética , Proteína Adaptadora de Sinalização NOD1/genética , Survivina , Fator de Necrose Tumoral alfa/genética , Proteína X Associada a bcl-2/genéticaRESUMO
HAX-1 is a multi-functional protein that is involved in the regulation of apoptosis, cell motility and calcium homeostasis. It is also reported to bind RNA: it associates with structural motifs present in the 3' untranslated regions of at least two transcripts, but the functional significance of this binding remains unknown. Although HAX-1 has been detected in various cellular compartments, it is predominantly cytoplasmic. Our detailed localization studies of HAX-1 isoforms revealed partial nuclear localization, the extent of which depends on the protein isoform. Further studies demonstrated that HAX-1 is in fact a nucleocytoplasmic shuttling protein, dependent on the exportin 1 nuclear export receptor. Systematic mutagenesis allowed identification of the two nuclear export signals in the HAX-1 sequence. HAX-1 nuclear accumulation was observed after inhibition of nuclear export by leptomycin B, but also after specific cellular stress. The biological role of HAX-1 nuclear localization and shuttling remains to be established, but the HAX-1 transcript-binding properties suggest that it may be connected to mRNA processing and surveillance. In this study, HAX-1 status was shown to influence mRNA levels of DNA polymerase ß, one of the HAX-1 mRNA targets, although this effect becomes pronounced only after specific stress is applied. Moreover, HAX-1 tethering to the reporter transcript caused a significant decrease in its expression. Additionally, the HAX-1 co-localization with P-body markers, reported here, implies a role in mRNA processing. These results suggest that HAX-1 may be involved in the regulation of expression of bound transcripts, possibly as part of the stress response.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/fisiologia , Núcleo Celular/metabolismo , Transporte Ativo do Núcleo Celular , Proteínas Adaptadoras de Transdução de Sinal/química , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Sequência de Aminoácidos , Animais , Arsenitos/farmacologia , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Linhagem Celular , DNA Polimerase beta/genética , DNA Polimerase beta/metabolismo , Regulação da Expressão Gênica , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Carioferinas/metabolismo , Camundongos , Dados de Sequência Molecular , Sinais de Exportação Nuclear , Isoformas de Proteínas/química , Isoformas de Proteínas/metabolismo , Isoformas de Proteínas/fisiologia , Transporte Proteico , Processamento Pós-Transcricional do RNA , Ratos , Receptores Citoplasmáticos e Nucleares/metabolismo , Estresse Fisiológico , Teratogênicos/farmacologia , Proteína Exportina 1RESUMO
BACKGROUND: The Lufwanyama Neonatal Survival Project ("LUNESP") was a cluster randomized, controlled trial that showed that training traditional birth attendants (TBAs) to perform interventions targeting birth asphyxia, hypothermia, and neonatal sepsis reduced all-cause neonatal mortality by 45%. This companion analysis was undertaken to analyze intervention costs and cost-effectiveness, and factors that might improve cost-effectiveness. METHODS AND FINDINGS: We calculated LUNESP's financial and economic costs and the economic cost of implementation for a forecasted ten-year program (2011-2020). In each case, we calculated the incremental cost per death avoided and disability-adjusted life years (DALYs) averted in real 2011 US dollars. The forecasted 10-year program analysis included a base case as well as 'conservative' and 'optimistic' scenarios. Uncertainty was characterized using one-way sensitivity analyses and a multivariate probabilistic sensitivity analysis. The estimated financial and economic costs of LUNESP were $118,574 and $127,756, respectively, or $49,469 and $53,550 per year. Fixed costs accounted for nearly 90% of total costs. For the 10-year program, discounted total and annual program costs were $256,455 and $26,834 respectively; for the base case, optimistic, and conservative scenarios, the estimated cost per death avoided was $1,866, $591, and $3,024, and cost per DALY averted was $74, $24, and $120, respectively. Outcomes were robust to variations in local costs, but sensitive to variations in intervention effect size, number of births attended by TBAs, and the extent of foreign consultants' participation. CONCLUSIONS: Based on established guidelines, the strategy of using trained TBAs to reduce neonatal mortality was 'highly cost effective'. We strongly recommend consideration of this approach for other remote rural populations with limited access to health care.
Assuntos
Mortalidade Infantil , Tocologia/economia , Tocologia/educação , Análise Custo-Benefício , Feminino , Humanos , Recém-Nascido , Análise Multivariada , Gravidez , ZâmbiaRESUMO
OBJECTIVE: To provide relevant details on how interventions in the Lufwanyama Neonatal Survival Project (LUNESP) were developed and how Zambian traditional birth attendants (TBAs) were trained to perform them. METHODS: The study tested 2 interventions: a simplified version of the American Academy of Pediatrics' neonatal resuscitation protocol (NRP); and antibiotics with facilitated referral (AFR). RESULTS: Key elements that enabled the positive study result were: focusing on common and correctible causes of mortality; selecting a study population with high unmet public health need; early community mobilization to build awareness and support; emphasizing simplicity in the intervention technology and algorithms; using a traditional training approach appropriate to students with low literacy rates; requiring TBAs to demonstrate their competence before completing each workshop; and minimizing attrition of skills by retraining and reassessing the TBAs regularly throughout the study. CONCLUSION: An effective NRP training model was created that is suitable for community-based neonatal interventions, in research or programmatic settings, and by practitioners with limited obstetric skills and low rates of literacy. Clinicaltrials.gov NCT00518856.
Assuntos
Competência Clínica , Parto Obstétrico/educação , Mortalidade Infantil , Tocologia/educação , Algoritmos , Antibacterianos/uso terapêutico , Parto Obstétrico/normas , Feminino , Humanos , Recém-Nascido , Tocologia/normas , Gravidez , Resultado da Gravidez , Encaminhamento e Consulta , Ressuscitação/métodos , ZâmbiaRESUMO
CONTEXT: In obesity, the cells are exposed to excessive amounts of nutrients, especially free fatty acids (FFAs) that induce a variety of metabolic changes. OBJECTIVE: We investigated the effect of FFAs on the mitochondrial function in different cell populations under stress conditions. METHODS: Human adipose tissue progenitor cells (SVF) or endothelial cells (HUVECs) were incubated with 30µM of selected saturated or unsaturated FFA for 24 h, at times supplemented with 5ng/mL tumour necrosis factor alpha (TNFα) for the last 4 h. Changes in oxygen respiration rate, mitochondrial membrane potential (mitoMP) and total ATP content were monitored. RESULTS: Saturated palmitic acid demonstrated no effect, while a selection of unsaturated FFAs ameliorated metabolism of the progenitor SVF cells. TNFα either did not affect or nullified some of the favourable FFA-induced effects. CONCLUSIONS: The mitoMP was the most sensitive parameter reflecting positive impact of the unsaturated FFA on the adipose SVF cells' metabolism.
Assuntos
Adipócitos/efeitos dos fármacos , Ácidos Graxos Insaturados/farmacologia , Ácidos Graxos/farmacologia , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células-Tronco Mesenquimais/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Trifosfato de Adenosina/metabolismo , Adipócitos/citologia , Adipócitos/metabolismo , Tecido Adiposo/citologia , Tecido Adiposo/efeitos dos fármacos , Tecido Adiposo/metabolismo , Respiração Celular/efeitos dos fármacos , Células Cultivadas , Células Endoteliais da Veia Umbilical Humana/citologia , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Mitocôndrias/metabolismo , Ácido Palmítico/farmacologia , Fator de Necrose Tumoral alfa/farmacologiaRESUMO
Changes in the inner mitochondrial membrane potential (∆ψ) may lead either to apoptosis or to protective autophagy. Connexin 43 (Cx43), a gap junction protein, is suggested to affect mitochondrial membrane permeability. The aim of our study was to analyze Cx43 gene expression, Cx43 protein localization and mitochondrial function in the human endothelial cells stressed by dietary-free fatty acids (FFA) and TNFα. Human endothelial cells (HUVECs) were incubated with (10-30 uM) palmitic (PA), oleic (OA), eicosapentaenoic (EPA) or arachidonic (AA) acids for 24 h. TNFα (5 ng/ml) was added at the last 4 h of incubation. The Cx43 gene expression was analyzed by the quantitative real-time PCR. The Cx43 protein concentrations in whole cells and in the isolated mitochondria were measured. Changes in ∆ψ and Cx43 localization were analyzed by flow cytometry or fluorescence microscopy. Generated ATP was measured by a luminescence assay. TNFα, PA and OA significantly decreased ∆ψ, while AA (P = 0.047) and EPA (P = 0.004) increased ∆ψ value. Preincubation with EPA or AA partially prevented the TNFα-induced decrease of ∆ψ. Incubation with AA resulted in up-regulation of the Cx43 gene expression. AA or PA significantly increased Cx43 protein content; however, presence of TNFα in general aggravated the negative effect of FFA. Only EPA was found to increase ATP generation in HUVECs. The fatty acid-specific induction of changes in Cx43 expression and protein concentration as well as the normalization of ∆ψ and increase of ATP generation seem to be the separate, independent mechanisms of FFA-mediated modulatory effect in the human endothelial cells pathology.
RESUMO
Humanin (HN) is a newly discovered 24-amino acid peptide, which may suppress neuronal cell death. HN cDNA includes the open reading frame (HN-ORF) of 75 bases, located 950 bases downstream of the 5' end of the HN cDNA. It was demonstrated that HN cDNA is 99% identical with mitochondrial DNA (mtDNA) sequence. HN homologues have been identified as expressed sequence tags (ESTs) in rat and nematode. Certain regions homologous to the HN cDNA exist on human chromosomes. HN forms homodimers and multimers and this seems to be essential for the peptide functions. HN acts as a ligand for formyl peptide receptor-like 1 (FPRL1) and 2 (FPRL2). It was demonstrated that HN plays a protective role by an antiapoptotic activity interfering with Bax activation, and suppressing Bax-dependent apoptosis. HN is also shown to suppress the c-Jun N-terminal kinase (JNK) and ASK/JNK-mediated neuronal cell death. Several studies also confirm that HN could be important in prevention of angiopathy-associated Alzheimer's disease dementia, diseases related to mitochondrial dysfunction (MELAS), and other types of beta-amyloid accumulation associated neurodegeneration. A very recent study demonstrated a pluripotent cytoprotective effect and mechanisms of HNs in cells other than from the CNS, such as germ cells, or panreatic b-cells, and potent physiological consequences that result from HN interaction with IGFBP3 and STAT3. The in vivo studies suggest that humanin may protect against cognitive impairment, also due to ischemia/reperfusion injury.