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1.
Br J Nutr ; 131(8): 1405-1412, 2024 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-38163989

RESUMO

Breast-feeding is associated with fewer comorbidities in very-low-birth-weight (VLBW) preterm infants. Bronchopulmonary dysplasia (BPD) of VLBW infants is a multifactorial pathology in which nutritional aspects may be of special importance. The aim of this study is to determine, in a cohort of VLBW infants, whether breast milk nutrition is associated with a reduced prevalence and severity of BPD. A retrospective study was conducted to record the intake of mother's own milk (MOM), pasteurised donor human milk or preterm formula milk in the first 2 weeks of postnatal life of 566 VLBW newborns at our hospital during the period January 2008-December 2021. After applying the relevant exclusion criteria, data for 489 VLBW infants were analysed; 195 developed some degree of BPD. Moderate or severe BPD is associated with less weight gain. Moreover, the preferential ingestion of breast milk in the first and second postnatal weeks had effects associated with lower OR for BPD, which were statistically demonstrable for mild (OR 0·16; 95 % CI 0·03, 0·71) and severe (OR 0·08; 95 % CI 0·009, 0·91) BPD. Breast-feeding during the first weeks of postnatal life is associated with a reduced prevalence of BPD, which is frequently associated with less weight gain as a result of greater respiratory effort with greater energy expenditure.


Assuntos
Displasia Broncopulmonar , Recém-Nascido Prematuro , Lactente , Feminino , Recém-Nascido , Humanos , Displasia Broncopulmonar/epidemiologia , Displasia Broncopulmonar/prevenção & controle , Fatores de Proteção , Estudos Retrospectivos , Leite Humano , Recém-Nascido de muito Baixo Peso , Aumento de Peso
2.
Br J Nutr ; 130(12): 2095-2103, 2023 12 28.
Artigo em Inglês | MEDLINE | ID: mdl-37317807

RESUMO

Premature birth, bronchopulmonary dysplasia or restrictive nutrition in the first weeks of postnatal life may have repercussions on lung development and affect long-term lung function outcomes. This prospective observational study is based on a cohort of 313 very low birth weight (VLBW) neonates, born between 1 January 2008 and 1 December 2016. The daily intake of calories, protein, fat and carbohydrates during the first week of life and evidence of inadequate weight gain (Δwt) until week 36 of gestational age (GA) were recorded. FEV1, FEF25-75 %, forced vital capacity (FVC) and the FEV1/FVC ratio were determined. The relations between these parameters were determined by regression analysis. Spirometric parameters were obtained for 141 children with a mean age of 9 years (95 % CI 7, 11); 69 of them (48·9 %) had presented wheezing episodes on more than three occasions. In addition, 60 (42·5 %) had a history of bronchopulmonary dysplasia. Of these, n 40 (66·6 %) had a history of wheezing. Significant association between protein/energy intake in the first week of life and the lung function parameters analysed was observed. Poor Δwt to GA week 36 was significantly associated with decreased mean pulmonary flow. Inadequate protein/energy intake in the first week of life of VLBW newborns and poor Δwt to week 36 of GA is associated with a significant worsening of lung function parameters.


Assuntos
Displasia Broncopulmonar , Criança , Humanos , Recém-Nascido , Peso ao Nascer , Ingestão de Energia , Recém-Nascido de muito Baixo Peso , Pulmão , Sons Respiratórios
3.
Health Promot J Austr ; 34(1): 60-69, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36054639

RESUMO

ISSUE ADDRESSED: Firefighting is physically and mentally taxing and recruits are expected to have optimal health and fitness. However, physical fitness tends to decline following initial training, placing firefighters at an increased risk for stress and injury. Efforts are needed to engage and support firefighters in maintaining adequate health and fitness to withstand the rigorous demands of their occupation. This study examined the feasibility of TARP, a pragmatic strength and conditioning intervention for metropolitan-based firefighters, delivered in collaboration with a professional National Rugby League club. METHODS: A mixed-methods approach was utilised to examine program implementation, recruitment and sample characteristics, intervention satisfaction and acceptability, and participants' response to the intervention. Evaluation measures included field notes taken during steering committee meetings, participant flow data, baseline and follow-up outcome measures, self-report questionnaires, and telephone interviews with a sample of participants. RESULTS: Participants (N = 113) were predominantly men (82%) with a mean age of 43 ± 9.3 years and BMI of 26.6 ± 2.9 kg/m2 . Program satisfaction was high (95% very satisfied or somewhat satisfied) among program completers (42% retention). Key strengths of the program included delivery through the professional sports club, quality of facilities and equipment, and scheduling flexibility. Future programs should consider incorporating education or training to support behaviour change maintenance and strategies to retain participants at follow-up. CONCLUSIONS: Results provide valuable insights into the design and delivery of interventions for firefighters and demonstrate the importance of strong partnerships between community stakeholders.


Assuntos
Bombeiros , Masculino , Humanos , Adulto , Pessoa de Meia-Idade , Feminino , Estudos de Viabilidade , Exercício Físico , Atletas
4.
Am J Perinatol ; 2022 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-36451626

RESUMO

OBJECTIVE: This article describes the results of a study investigating the sensitivity and specificity of the Newborn Infant Parasympathetic Evaluation (NIPE) index for detecting the physiological changes resulting from nociception in painful procedures in very low birth weight (VLBW) infants. STUDY DESIGN: A prospective observational study was carried on of 44 newborns at 23 to 32 weeks' gestational age. The sensitivity and specificity of the NIPE index are analyzed using a receiver operating characteristic curve. Most of the painful procedures performed were skin-lancing and venipunctures. Nonpainful procedures consist of no intervention, with an interval of at least 1 hour with painful procedures in each newborn. RESULTS: The accuracy of the NIPE index to diagnose mild nociceptive stimulation in VLBW newborns is 73.2%. CONCLUSION: The NIPE index is a useful technique for assessing nociceptive stimulation in newborns, presenting less observer-dependent variability than other pain assessment scales. KEY POINTS: · The NIPE index offers an objective assessment of pain.. · Moderate-high sensitivity of the NIPE index in the evaluation of pain in premature newborns.. · Painful procedures in VLBW newborns are reflected as a decrease in the NIPE score..

5.
Br J Nutr ; 127(4): 580-588, 2022 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-33866979

RESUMO

Inadequate nutrition during a critical period of development - as is the case during gestation and the first days of life, especially in very-low-birth-weight (VLBW) infants, can impact on neurodevelopment and favour co-morbidities. In this study, we evaluate how neurodevelopment may be affected by intra-uterine growth (IUGR) restriction and by an inadequate intake of nutritional energy during the early neonatal period. A longitudinal cohort study was conducted to analyse the nutritional contributions received during the first week of life, among a population of 396 VLBW infants. Motor, cognitive, sensory and behavioural development was assessed at 14, 25, 33 and 50 months. The association between IUGR, postnatal energy restriction and neurodevelopment was examined using multivariate logistic regression techniques. Mild cognitive delay was observed in 35·6 % of neonates with IUGR and in 24 % of those with appropriate birth weight. IUGR is associated with behavioural disorder (OR 2·60; 95 % CI 1·25, 5·40) and delayed cognitive development (OR 2·64; 95 % CI 1·34, 5·20). Energy restriction during the first week of life is associated with visual deficiency (OR 2·96; 95 % CI 1·26, 6·84) and cerebral palsy (OR 3·05; CI 95 % 1·00, 9·54). In VLBW infants, IUGR is associated with behavioural disorder, while postnatal energy restriction is significantly associated with motor disorder, infantile cerebral palsy and sensory disorder.


Assuntos
Paralisia Cerebral , Peso ao Nascer , Retardo do Crescimento Fetal , Seguimentos , Humanos , Lactente , Recém-Nascido , Recém-Nascido de muito Baixo Peso , Estudos Longitudinais
6.
Patient Educ Couns ; 105(7): 2489-2496, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-34823926

RESUMO

OBJECTIVE: This study aimed to 1) understand factors impacting the implementation of exercise communication and referral, and 2) explore integrated clinical approaches to exercise communication and referral in cancer care. METHODS: Seven focus groups (N = 53) were conducted with clinicians and exercise professionals throughout Sydney, Australia. A sub-sample of participants (n = 9) attended a half-day workshop to identifying best practice approaches for moving forward. Data were analysed using thematic content analysis. RESULTS: Two themes emerged: 1) Factors impacting the knowledge-to-action gap, inclusive of limited exercise specific knowledge and training opportunities, funding structure, and current referral process, and 2) Recommendations for a consistent and efficient way forward, detailing the need for oncologist-initiated communication, distribution of cancer-exercise resources, and access to exercise professionals with cancer expertise. CONCLUSIONS: This study identified factors (e.g., cancer-exercise specific training, integration of exercise physiologists) influencing exercise counselling and referral. A potential implementation-referral approach accounting for these factors and how to incorporate exercise into a standard model of cancer care, is described. Future testing is required to determine feasibility and practicality of these approaches. PRACTICAL IMPLICATIONS: A pragmatic model is provided to guide implementation-referral, inclusive of oncologist-initiated communication exchange, relevant resources, and access to exercise professionals with cancer expertise.


Assuntos
Neoplasias , Encaminhamento e Consulta , Atitude do Pessoal de Saúde , Austrália , Aconselhamento , Exercício Físico , Humanos , Neoplasias/terapia , Pesquisa Qualitativa
7.
Elife ; 102021 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-34032214

RESUMO

The hemibrain connectome provides large-scale connectivity and morphology information for the majority of the central brain of Drosophila melanogaster. Using this data set, we provide a complete description of the Drosophila olfactory system, covering all first, second and lateral horn-associated third-order neurons. We develop a generally applicable strategy to extract information flow and layered organisation from connectome graphs, mapping olfactory input to descending interneurons. This identifies a range of motifs including highly lateralised circuits in the antennal lobe and patterns of convergence downstream of the mushroom body and lateral horn. Leveraging a second data set we provide a first quantitative assessment of inter- versus intra-individual stereotypy. Comparing neurons across two brains (three hemispheres) reveals striking similarity in neuronal morphology across brains. Connectivity correlates with morphology and neurons of the same morphological type show similar connection variability within the same brain as across two brains.


Assuntos
Conectoma , Condutos Olfatórios/fisiologia , Animais , Conjuntos de Dados como Assunto , Drosophila melanogaster/fisiologia , Feminino , Interneurônios/fisiologia
8.
Elife ; 92020 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-33315010

RESUMO

Making inferences about the computations performed by neuronal circuits from synapse-level connectivity maps is an emerging opportunity in neuroscience. The mushroom body (MB) is well positioned for developing and testing such an approach due to its conserved neuronal architecture, recently completed dense connectome, and extensive prior experimental studies of its roles in learning, memory, and activity regulation. Here, we identify new components of the MB circuit in Drosophila, including extensive visual input and MB output neurons (MBONs) with direct connections to descending neurons. We find unexpected structure in sensory inputs, in the transfer of information about different sensory modalities to MBONs, and in the modulation of that transfer by dopaminergic neurons (DANs). We provide insights into the circuitry used to integrate MB outputs, connectivity between the MB and the central complex and inputs to DANs, including feedback from MBONs. Our results provide a foundation for further theoretical and experimental work.


Assuntos
Conectoma , Drosophila melanogaster/fisiologia , Corpos Pedunculados/fisiologia , Animais , Mapeamento Encefálico , Corpos Pedunculados/inervação
9.
Curr Biol ; 30(16): 3167-3182.e4, 2020 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-32619476

RESUMO

Animals exhibit innate and learned preferences for temperature and humidity-conditions critical for their survival and reproduction. Leveraging a whole-brain electron microscopy volume, we studied the adult Drosophila melanogaster circuitry associated with antennal thermo- and hygrosensory neurons. We have identified two new target glomeruli in the antennal lobe, in addition to the five known ones, and the ventroposterior projection neurons (VP PNs) that relay thermo- and hygrosensory information to higher brain centers, including the mushroom body and lateral horn, seats of learned and innate behavior. We present the first connectome of a thermo- and hygrosensory neuropil, the lateral accessory calyx (lACA), by reconstructing neurons downstream of heating- and cooling-responsive VP PNs. A few mushroom body-intrinsic neurons solely receive thermosensory input from the lACA, while most receive additional olfactory and thermo- and/or hygrosensory PN inputs. Furthermore, several classes of lACA-associated neurons form a local network with outputs to other brain neuropils, suggesting that the lACA serves as a hub for thermo- and hygrosensory circuitry. For example, DN1a neurons link thermosensory PNs in the lACA to the circadian clock via the accessory medulla. Finally, we survey strongly connected downstream partners of VP PNs across the protocerebrum; these include a descending neuron targeted by dry-responsive VP PNs, meaning that just two synapses might separate hygrosensory inputs from motor circuits. These data provide a comprehensive first- and second-order layer analysis of Drosophila thermo- and hygrosensory systems and an initial survey of third-order neurons that could directly modulate behavior.


Assuntos
Conectoma , Drosophila melanogaster/fisiologia , Neurônios/metabolismo , Neurópilo/metabolismo , Células Receptoras Sensoriais/metabolismo , Sinapses/fisiologia , Termorreceptores/metabolismo , Animais , Feminino , Neurônios/citologia , Condutos Olfatórios
10.
Curr Biol ; 30(16): 3183-3199.e6, 2020 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-32619485

RESUMO

Nervous systems contain sensory neurons, local neurons, projection neurons, and motor neurons. To understand how these building blocks form whole circuits, we must distil these broad classes into neuronal cell types and describe their network connectivity. Using an electron micrograph dataset for an entire Drosophila melanogaster brain, we reconstruct the first complete inventory of olfactory projections connecting the antennal lobe, the insect analog of the mammalian olfactory bulb, to higher-order brain regions in an adult animal brain. We then connect this inventory to extant data in the literature, providing synaptic-resolution "holotypes" both for heavily investigated and previously unknown cell types. Projection neurons are approximately twice as numerous as reported by light level studies; cell types are stereotyped, but not identical, in cell and synapse numbers between brain hemispheres. The lateral horn, the insect analog of the mammalian cortical amygdala, is the main target for this olfactory information and has been shown to guide innate behavior. Here, we find new connectivity motifs, including axo-axonic connectivity between projection neurons, feedback, and lateral inhibition of these axons by a large population of neurons, and the convergence of different inputs, including non-olfactory inputs and memory-related feedback onto third-order olfactory neurons. These features are less prominent in the mushroom body calyx, the insect analog of the mammalian piriform cortex and a center for associative memory. Our work provides a complete neuroanatomical platform for future studies of the adult Drosophila olfactory system.


Assuntos
Conectoma , Drosophila melanogaster/fisiologia , Interneurônios/metabolismo , Corpos Pedunculados/metabolismo , Neurônios/metabolismo , Condutos Olfatórios , Sinapses/fisiologia , Animais , Feminino , Interneurônios/citologia , Corpos Pedunculados/citologia , Neurônios/citologia , Olfato
11.
Invest New Drugs ; 37(5): 837-848, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-30465316

RESUMO

Caffeic acid phenethyl ester (CAPE) is a phenolic compound initially identified in bee glue. CAPE is reported to exhibit antitumor activity in many cancer models. However, the effect of CAPE on multiple myeloma (MM) is not well studied. We investigated the anti-myeloma effect of CAPE, and the data showed that CAPE inhibited the growth of human MM cells in a dose (1 ~ 30 µM) and time (24 ~72 h) dependent manner without altering the viability of normal human peripheral blood B cells. Stress and toxicity pathway analysis demonstrated that CAPE, in a dose- and time-related fashion, induced the expression of apoptotic and oxidative stress-response genes including growth arrest and DNA-damage inducible, alpha and gamma (GADD45A and GADD45G) and heme oxygenase-1. Apoptosis of MM cells by CAPE was further confirmed through flow cytometric analysis with up to 50% apoptotic cells induced by 50 µM CAPE within 24 h. Western blot analysis revealed the CAPE-induced activation of apoptosis executioner enzyme caspase-3, and corresponding cleavage of its downstream target poly(ADP-ribose)polymerase (PARP). The oxidative stress caused by CAPE cytotoxicity in MM cells was evaluated through measurement of reactive oxygen species (ROS) level, antioxidant intervention and glutathione depletion. The intracellular ROS level was not elevated by CAPE, but the pretreatment of antioxidant (N-acetyl cysteine) and glutathione synthesis inhibitor (buthionine sulfoximine) suggested that CAPE may cause oxidative stress by decrease of intracellular antioxidant level rather than over production of ROS. These data suggest that CAPE promotes apoptosis through oxidative stress in human multiple myeloma cells.


Assuntos
Apoptose/efeitos dos fármacos , Biomarcadores Tumorais/genética , Ácidos Cafeicos/farmacologia , Mieloma Múltiplo/patologia , Estresse Oxidativo/efeitos dos fármacos , Álcool Feniletílico/análogos & derivados , Antioxidantes/metabolismo , Movimento Celular , Proliferação de Células/efeitos dos fármacos , Perfilação da Expressão Gênica , Humanos , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/genética , Álcool Feniletílico/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Células Tumorais Cultivadas
12.
Curr Biol ; 27(17): R839-R842, 2017 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-28898645

RESUMO

A neuron responding to moist air and its ionotropic receptor have been identified in Drosophila melanogaster. Moreover, second-order neurons integrate temperature and humidity information before reaching higher brain centres.


Assuntos
Proteínas de Drosophila , Drosophila , Animais , Encéfalo , Drosophila melanogaster , Umidade , Neurobiologia , Temperatura
13.
PLoS Biol ; 12(12): e1002030, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25549104

RESUMO

We have developed and tested two linked but separable structured inquiry exercises using a set of Drosophila melanogaster GAL4 enhancer trap strains for an upper-level undergraduate laboratory methods course at Bucknell University. In the first, students learn to perform inverse PCR to identify the genomic location of the GAL4 insertion, using FlyBase to identify flanking sequences and the primary literature to synthesize current knowledge regarding the nearest gene. In the second, we cross each GAL4 strain to a UAS-CD8-GFP reporter strain, and students perform whole mount CNS dissection, immunohistochemistry, confocal imaging, and analysis of developmental expression patterns. We have found these exercises to be very effective in teaching the uses and limitations of PCR and antibody-based techniques as well as critical reading of the primary literature and scientific writing. Students appreciate the opportunity to apply what they learn by generating novel data of use to the wider research community.


Assuntos
Currículo , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Elementos Facilitadores Genéticos , Laboratórios , Aprendizagem , Fatores de Transcrição/genética , Universidades , Animais , Sequência de Bases , Encéfalo/metabolismo , Regulação da Expressão Gênica , Genes de Insetos , Dados de Sequência Molecular , Corpos Pedunculados/metabolismo , Reação em Cadeia da Polimerase
14.
J Phys Chem A ; 118(1): 197-207, 2014 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-24350909

RESUMO

A density functional theory study was performed to analyze the electron donor-acceptor properties of the cis and trans isomers of a novel azobenzene-containing tetraphenylporphyrin (TPPN2PhC14H29) with different substituents (Br or TMS). In general, the trans isomers are better electron acceptors than the correspondent cis homologues. Their UV-vis spectra were also obtained and a comparison with available experimental results is included. According to these results, the azo compounds reported here are promising materials for the elaboration of dye-sensitized solar cells because their HOMO-LUMO gaps are close to 2 eV. Moreover, the energy of the high intensity absorption bands also fulfills the requirements needed for the operation of a solar cell built with TiO2 and the I(-)/I3(-) pair.

15.
Curr Biol ; 23(19): 1908-13, 2013 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-24055154

RESUMO

An often-overlooked aspect of neural plasticity is the plasticity of neuronal composition, in which the numbers of neurons of particular classes are altered in response to environment and experience. The Drosophila brain features several well-characterized lineages in which a single neuroblast gives rise to multiple neuronal classes in a stereotyped sequence during development. We find that in the intrinsic mushroom body neuron lineage, the numbers for each class are highly plastic, depending on the timing of temporal fate transitions and the rate of neuroblast proliferation. For example, mushroom body neuroblast cycling can continue under starvation conditions, uncoupled from temporal fate transitions that depend on extrinsic cues reflecting organismal growth and development. In contrast, the proliferation rates of antennal lobe lineages are closely associated with organismal development, and their temporal fate changes appear to be cell cycle-dependent, such that the same numbers and types of uniglomerular projection neurons innervate the antennal lobe following various perturbations. We propose that this surprising difference in plasticity for these brain lineages is adaptive, given their respective roles as parallel processors versus discrete carriers of olfactory information.


Assuntos
Encéfalo/fisiologia , Drosophila melanogaster/fisiologia , Corpos Pedunculados/metabolismo , Plasticidade Neuronal , Condutos Olfatórios/metabolismo , Animais , Antenas de Artrópodes/citologia , Antenas de Artrópodes/metabolismo , Diferenciação Celular , Linhagem da Célula , Proliferação de Células , Proteínas de Drosophila/biossíntese , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/genética , Proteínas de Fluorescência Verde/genética , Insulina/metabolismo , Larva , Proteínas do Tecido Nervoso/genética , Condutos Olfatórios/citologia , Fatores do Domínio POU/genética , Receptores Proteína Tirosina Quinases/biossíntese , Receptores Proteína Tirosina Quinases/genética , Receptores Proteína Tirosina Quinases/metabolismo , Inanição , Fatores de Transcrição/genética
16.
J Phys Chem B ; 117(15): 4050-61, 2013 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-23560647

RESUMO

We present a density functional theory (DFT) and time-dependent density functional theory (TD-DFT) study on the stability, antioxidant properties with respect to the single electron transfer mechanism, and electronic absorption spectra of some isomers (9-cis, 13-cis, and 15-cis) of carotenoids such as astaxanthin, lycopene, and those present in virgin olive oil (lutein, ß-carotene, neoxanthin, antheraxanthin, violaxanthin, neochrome, luteoxanthin, mutatoxanthin, and violaxanthin). In general, the calculated relative stability of the cis isomers appears to be in line with experimental observations. It is predicted that the above-mentioned carotenoids (cis and trans isomers) will transfer one electron to the (•)OH radical. However, this transference is not plausible with radicals such as (•)OOH, (•)OC2H5, (•)OOC2H5, (•)NO2, and (•)OOCH2CH═CH2. On the other hand, some carotenoids (ß-carotene, lycopene, lutein, astaxanthin, violaxanthin, and antheraxanthin) will likely accept, in a medium of low polarity, one electron from the radical (•)O2(-). However, neoxanthin, auroxanthin, mutatoxanthin, luteoxanthin, and neochrome would not participate in such an electronic transfer mechanism. The TD-DFT studies show that neutral species of the cis and trans isomers maintain the same color. On the contrary, the ionic species undergo a "bleaching" process where the absorption wavelengths shift to longer values (>700 nm). Additionally, the formation of a complex between astaxanthin and Cu(2+) is explored as well as the effect that the metal atom will have in the UV-vis spectrum.


Assuntos
Antioxidantes/química , Carotenoides/química , Pigmentos Biológicos/química , Óleos de Plantas/química , Teoria Quântica , Complexos de Coordenação/química , Isomerismo , Licopeno , Azeite de Oliva , Termodinâmica , Xantofilas/química
17.
Neural Dev ; 7: 31, 2012 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-22967828

RESUMO

BACKGROUND: In holometabolous insects such as Drosophila melanogaster, neuroblasts produce an initial population of diverse neurons during embryogenesis and a much larger set of adult-specific neurons during larval life. In the ventral CNS, many of these secondary neuronal lineages differ significantly from one body segment to another, suggesting a role for anteroposterior patterning genes. RESULTS: Here we systematically characterize the expression pattern and function of the Hox gene Ultrabithorax (Ubx) in all 25 postembryonic lineages. We find that Ubx is expressed in a segment-, lineage-, and hemilineage-specific manner in the thoracic and anterior abdominal segments. When Ubx is removed from neuroblasts via mitotic recombination, neurons in these segments exhibit the morphologies and survival patterns of their anterior thoracic counterparts. Conversely, when Ubx is ectopically expressed in anterior thoracic segments, neurons exhibit complementary posterior transformation phenotypes. CONCLUSION: Our findings demonstrate that Ubx plays a critical role in conferring segment-appropriate morphology and survival on individual neurons in the adult-specific ventral CNS. Moreover, while always conferring spatial identity in some sense, Ubx has been co-opted during evolution for distinct and even opposite functions in different neuronal hemilineages.


Assuntos
Proteínas de Drosophila/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Proteínas de Homeodomínio/metabolismo , Sistema Nervoso/crescimento & desenvolvimento , Sistema Nervoso/metabolismo , Fatores de Transcrição/metabolismo , Animais , Animais Geneticamente Modificados , Morte Celular/genética , Drosophila , Proteínas de Drosophila/genética , Drosophila melanogaster/embriologia , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/genética , Proteínas de Homeodomínio/genética , Larva , Fatores de Transcrição/genética
18.
J Phys Chem B ; 116(32): 9668-75, 2012 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-22853004

RESUMO

A density functional theory (DFT) study on the free radical (OH(•) and OOH(•)) scavenging properties of some mono- and polysaccharides is presented. Two mechanisms, single electron transfer (SET) and hydrogen atom transfer (HAT), are considered. The former mechanism is studied by making use of the vertical ionization energy and vertical electron affinity of the radicals and carbohydrates. It is confirmed that the SET mechanism is not plausible to occur. With respect to the HAT, not only does the OH(•) radical react preferably with one hydrogen atom bonded to one carbon atom, but also the reaction with a hydrogen atom bonded to an oxygen is possible. Finally, it is suggested that the carbohydrates are not able to directly scavenge OOH(•).


Assuntos
Carboidratos/química , Sequestradores de Radicais Livres/química , Teoria Quântica , Estrutura Molecular
19.
Food Funct ; 3(4): 442-50, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22327405

RESUMO

Mangosteen (Garcinia mangostana) is considered the queen of the tropical fruits. It has a dark red pericarp that is rich in bioactive compounds including xanthones, which have been classified as very good antioxidants from several experimental results. In this work, the antioxidant properties of twenty xanthones isolated from the pericarp of Garcinia mangostana are studied considering the single electron transfer mechanism (SET). According to their most acidic pK(a) value, under physiological conditions the monoanionic form is present in significant amounts. For this reason, eight deprotonated xanthones are also considered in this study. Quantum chemical calculations were performed in order to assess their free radical scavenging capacity in terms of vertical ionization energies and vertical electron affinities. With these two chemical descriptors it is possible to construct a map that allows a straightforward comparison of the electron transfer viability between any pair of reactants. Such a map for the studied xanthones and the free radicals ˙OH and O(2)˙(-), in aqueous solution, indicates that xanthones can either donate or accept electrons in order to deactivate free radicals. A new relationship between the ionization potential and the electron affinity is proposed to predict the thermochemical viability of the SET processes. The electron transfer reactions between xanthones and ˙OH or O(2)˙(-) are endergonic and, therefore, thermodynamically unfeasible. However, the reaction of deprotonated xanthones with ˙OH is exergonic. Thus, the deprotonated xanthones are more reactive than the neutral species through the SET mechanism. The monoanions of xanthones, which are present under physiological conditions were found to react with ˙OH at diffusion-limited rates.


Assuntos
Sequestradores de Radicais Livres/química , Garcinia mangostana/química , Extratos Vegetais/química , Xantonas/química , Elétrons , Radicais Livres/química , Frutas/química , Cinética , Termodinâmica
20.
Molecules ; 17(1): 1039-54, 2012 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-22267192

RESUMO

In this Density Functional Theory study, it became apparent that astaxanthin (ASTA) may form metal ion complexes with metal cations such as Ca⁺², Cu⁺², Pb⁺², Zn⁺², Cd⁺² and Hg⁺². The presence of metal cations induces changes in the maximum absorption bands which are red shifted in all cases. Therefore, in the case of compounds where metal ions are interacting with ASTA, they are redder in color. Moreover, the antiradical capacity of some ASTA-metal cationic complexes was studied by assessing their vertical ionization energy and vertical electron affinity, reaching the conclusion that metal complexes are slightly better electron donors and better electron acceptors than ASTA.


Assuntos
Quelantes/química , Simulação por Computador , Sequestradores de Radicais Livres/química , Modelos Químicos , Cátions Bivalentes/química , Complexos de Coordenação/química , Eletroquímica , Conformação Molecular , Solventes/química , Termodinâmica , Xantofilas/química
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