Analysis of 13 C and 14 C labeling in pyruvate and lactate in tumor and blood of lymphoma-bearing mice injected with 13 C- and 14 C-labeled pyruvate

Measurements of hyperpolarized 13C label exchange between injected [1‐13C]pyruvate and the endogenous tumor lactate pool can give an apparent first‐order rate constant for the exchange. The determination of the isotope flux, however, requires an estimate of the labeled pyruvate concentration in the tumor. This was achieved here by measurement of the tumor uptake of [1‐14C]pyruvate, which showed that <2% of the injected pyruvate reached the tumor site. Multiplication of this estimated labeled pyruvate concentration in the tumor with the apparent first‐order rate constant for hyperpolarized 13C label exchange gave an isotope flux that showed good agreement with a flux determined directly by the injection of non‐polarized [3‐13C]pyruvate, rapid excision of the tumor after 30 s and measurement of 13C‐labeled lactate concentrations in tumor extracts. The distribution of labeled lactate between intra‐ and extracellular compartments and the blood pool was investigated by imaging, by measurement of the labeled lactate concentration in blood and tumor, and by examination of the effects of a gadolinium contrast agent and a lactate transport inhibitor on the intensity of the hyperpolarized [1‐13C]lactate signal. These measurements showed that there was significant export of labeled lactate from the tumor, but that labeled lactate in the blood pool produced by the injection of hyperpolarized [1‐13C]pyruvate showed only relatively low levels of polarization. This study shows that measurements of hyperpolarized 13C label exchange between pyruvate and lactate in a murine tumor model can provide an estimate of the true isotope flux if the concentration of labeled pyruvate that reaches the tumor can be determined

Measurement of the absolute reflectance of polytetrafluoroethylene (PTFE) immersed in liquid xenon

The performance of a detector using liquid xenon (LXe) as a scintillator is strongly dependent on the collection efficiency for xenon scintillation light, which in turn is critically dependent on the reflectance of the surfaces that surround the active volume. To improve the light collection in such detectors the active volume is usually surrounded by polytetrafluoroethylene (PTFE) reflector panels, used due to its very high reflectance—even at the short wavelength of scintillation light of LXe (peaked at 178 nm). In this work, which contributed to the overall R&D effort towards the LUX-ZEPLIN (LZ) experiment, we present experimental results for the absolute reflectance measurements of three different PTFE samples (including the material used in the LUX detector) immersed in LXe for its scintillation light. The obtained results show that very high bi-hemispherical reflectance values (≥ 97%) can be achieved, enabling very low energy thresholds in liquid xenon scintillator-based detectors.Peer Reviewe

Microarray in clinical practice – utility vs complexity. Mixed phenotype of duplication 15q11.2q13.1 and deletion 16p11.2

Introduction: There’s a consensus to perform chromosomal microarray technique as first-tier clinical diagnostic test for individuals with developmental disabilities. However, given the complexity of clinical presentations, often several diagnostic methods are held before conducting microarray. Method: We report the case of a 5 year-old boy referred to Medical Genetics due to short stature, developmental disabilities and facial dysmorphic features. He was born from eutocic delivery after an uneventful pregnancy. He had psychomotor milestones delayed like sitting at 9 months and walking at 24 months, holding an immature broad-based gait. There was history of learning difficulties from both parents, and the mother has also short stature. On examination it was noted some facial dysmorphic features like high forehead, conical canines and rarefaction of the distal portion of the eyebrows. Due to the history of an episode of transient ataxia, and suspicion of an inherited metabolic disorder, he had already performed various analytical and imaging screenings, all normal. Results: Chromosomal microarray analysis revealed two pathogenic Copy Number Variants (CNV’s): 16p11.2 deletion and 15q11.2q13.1 duplication. The 15q11q13 microduplication syndrome (OMIM # 608636) is a very rare clinical entity with about 30 reported cases with maternal origin, and it is characterized by neurobehavioral disorder, hypotonia, cognitive impairment, epilepsy and short stature. The 16p11.2 microdeletion syndrome (OMIM # 613444) is also a rare clinical entity, with high penetrance, associated with obesity and developmental disabilities. Discussion: Despite the unquestionable utility of microarray, the correlation of the CNV's with the phenotype is often difficult by the rarity of these new microdeletion/duplication clinical entities. In this case the interpretation has increased difficulty because of the simultaneous existence of two distinct clinical entities. Segregation studies, which in the first step include parental analysis, are essential for genetic counseling and determining the risk of recurrence but also for a more accurate correlation genotype-phenotype

Effectiveness of the global protected area network in representing species diversity

The Fifth World Parks Congress in Durban, South Africa, announced in September 2003 that the global network of protected areas now covers 11.5% of the planet's land surface. This surpasses the 10% target proposed a decade earlier, at the Caracas Congress, for 9 out of 14 major terrestrial biomes. Such uniform targets based on percentage of area have become deeply embedded into national and international conservation planning. Although politically expedient, the scientific basis and conservation value of these targets have been questioned. In practice, however, little is known of how to set appropriate targets, or of the extent to which the current global protected area network fulfils its goal of protecting biodiversity. Here, we combine five global data sets on the distribution of species and protected areas to provide the first global gap analysis assessing the effectiveness of protected areas in representing species diversity. We show that the global network is far from complete, and demonstrate the inadequacy of uniform—that is, 'one size fits all'—conservation targets

What are seedless table grapes?

Grapes are one of the most commonly produced fruit crops in the world and an important fruit commodity that allows good profits to producers. According to their characteristics, grapes can be considered for different uses: wine production (varieties with higher acidity and moderate sugar content), table grapes for fresh consumption (varieties with low acidity, low sugar, and specific standards of size, color, and shape), and raisins (varieties with low acidity and high sugar). In the last years cultivation and consumption of table grapes (Vitis vinifera L.) has increased considerably, mainly due to seedless varieties. Consumers appreciate the absence of seeds and are willing to pay more for sweeter and more firm seedless grapes. However, for many people the term “seedless” has a negative connotation, associated with negative health effects or even genetic manipulation. Seedless grapes exist naturally or may be manipulated by plant breeders without using genetic engineering techniques. Is possible to distinguish two mechanisms of seedlessness: parthenocarpy (when the ovary can develop without fertilization of the ovum) and stenospermocarpy (embryo abortion occurs after fertilization, and partially developed seeds or traces of seed are visible). Shelf-life of seedless grapes is expected to be longer than seeded fruits, because seeds produce hormones that activate senescence. The current table grapes breeding programmes are designed to obtain varieties with good characteristics and mandatorily seedless. So, the absence of seeds, shape, colour, skin thickness, resistance against diseases and pests, ability to be transported without damage and shelf-life are the main criteria to select new varieties. However, those who think that these new seedless table grape varieties are a new development, you are mistaken! There are records of this type of grapes since the 19th century. The most widely commercialized seedless table grapes varieties in the world are Thompson seedless (first seedless variety cultivated in the world), Crimson and Autumn Royal. In recent years, the post-harvest research group at the University of Évora has developed several works, in partnership with regional enterprises, in the characterization and quality evaluation of several varieties of seedless table grapes. This work was supported by Portuguese National Funds through FCT – Fundação para a Ciência e a Tecnologia under Project UIDB/05183/2020 (MED). S. Ricardo-Rodrigues acknowledges a PhD grant from FCT (2021.07663.BD)

Estratégias de adaptação à incerteza climática para produção de trigo nas condições mediterrânicas do sul de Portugal: rega e fertilização azotada.

As alterações climáticas acentuam a irregularidade sazonal e inter-anual da temperatura e precipitação, características do clima Mediterrânico. As consequências desta variabilidade climática na produção de trigo fazem-se sentir ao nível do seu ciclo de desenvolvimento e da sua produtividade. Estratégias de adaptação baseadas na rega e na fertilização podem constituir ferramentas para fazer face aos impactos negativos da mudança climática. Neste estudo foram avaliados os efeitos da rega e da fertilização azotada sobre a produtividade do trigo mole na região do Alentejo, Sul de Portugal, em 2017/18. As respostas do trigo (fenologia, evolução populacional, produção de grão e suas componentes) foram avaliadas em dois ensaios, em Beja e Elvas. Testaram-se 3 tratamentos de rega e 8 tratamentos de tipo/fraccionamento do fertilizante azotado. Os tratamentos de rega foram: R0 (sem rega); R1 (rega com reposição de 100% da evapotranspiração cultural: ETc); R2 (rega com reposição de 100% da ETc apenas em quatro fases: início do encanamento; emborrachamento; ântese; enchimento do grão). No ensaio de Elvas testaram-se apenas os tratamentos R0 e R2 Os tratamentos de fertilização azotada incluíram 4 tipos de adubos (clássico; com inibidor de nitrificação, de libertação controlada e com inibidor da urease) aplicados totalmente à sementeira ou fraccionados ao longo do ciclo. No ensaio de Beja, não se verificaram efeitos significativos do regime hídrico em qualquer dos parâmetros analisados. A fertilização azotada influenciou a produção de grão e suas componentes, com os valores mais elevados de produção de grão a serem obtidos nos dois tratamentos com fertilizante clássico. Em Elvas, verificou-se forte influência do regime hídrico na evolução da população, na produção de grão e componentes da produção, com vantagem para o tratamento regado R2. Quanto ao fator fertilização azotada, não se obteve efeito significativo para quaisquer das variáveis estudadas. Os diferentes resultados obtidos nos dois locais de ensaios foram necessariamente influenciados pelas condições edafoclimáticas, nomeadamente pelo tipo de solo, mas, principalmente, pelo volume e distribuição da precipitação do ano de estudo, muito diferente do verificado em anos anteriores. Desta forma acentua-se a necessidade de prosseguir a avaliação da influência destes factores agronómicos na cultura do trigo em condições Mediterrânicas num contexto de vulnerabilidade climática

Emerging Enteropathogenic Escherichia coli Strains?

Escherichia coli strains of nonenteropathogenic serogroups carrying eae but lacking the enteropathogenic E. coli adherence factor plasmid and Shiga toxin DNA probe sequences were isolated from patients (children, adults, and AIDS patients) with and without diarrhea in Brazil. Although diverse in phenotype and genotype, some strains are potentially diarrheagenic