26 research outputs found

    Sustainable production of β-Xanthophylls in Saccharomyces Cerevisiae

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    Xanthophylls are a group of C40 pigments that belong to the carotenoids family. β-Xanthophylls, such as zeaxanthin, violaxanthin and neoxanthin are derived from β-carotene metabolism, and play a central role in the protection of photo-oxidative damage in plants and algae. These molecules have interesting applications as precursors of commercially relevant natural aromas, like safranal and damascenone. Furthermore, zeaxanthin is also widely used as a nutraceutical to improve ocular health. In this study, we engineered the yeast Saccharomyces cerevisiae to biosynthesize zeaxanthin and violaxanthin from glucose. We used integrative vectors to construct a genetic stable β-xanthophylls pathway in a β-carotenogenic yeast strain. To find an effective zeaxanthin biosynthetic enzyme, we compared the titers achieved by bacterial, plant and algal β-carotene hydroxylases. Additionally, we evaluated the effect of the chloroplast transit peptide of plant and algal enzymes on zeaxanthin biosynthesis. The strain that expressed truncated version of Solanum lycopersicum β-carotene hydroxylase showed the best performance, reaching up to 4.7 mg/g DCW of zeaxanthin after 72 h cultivation in shake-flasks. Zeaxanthin producing strains were transformed with zeaxanthin epoxidase genes to further extend the pathway to violaxanthin, which was measured by UPLC-MS. To the best of our knowledge, this work presents the highest titer of zeaxanthin in S. cerevisiae reported to date, the first zeaxanthin cell factory using β-carotene hydroxylase from plants, and the first heterologous biosynthesis of violaxanthin. Financial support of FONDECYT grant No.1170745 is greatly acknowledged. Vicente F. Cataldo acknowledges CONICYT for receiving graduate scholarship

    Caracterización del aceite de coquito de palma chilena (Jubaea chilensis)

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    The characteristics of the seeds from Chilean palm and the detailed composition of its fat are studied starting from 4 lots of seeds from the two regions being the major producers of Chilean palm seeds. From the proximate composition of the seeds a high content of fats is deduced with a mean value of 67.3%. The contents of proteins, carbohydrates and fibre were in the range of 7-11%. A detailed analysis of the fat indicates a high content of saturated fatty acids being capric, caprilic, lauric and miristic acids the major fatty acids. For this reason the presence of a high percentage of medium-chain triglycerides are detected in the triglyceride analysis. As for tocopherols, the fat contains low amounts of α-, γ- y δ-tocopherol with a total average of 84 mg/kg. Concerning phytosterols, the total content was around 1000 mg/kg being β-sitosterol and Δ7-estigmastenol the two major sterolsSe analizan las características generales del coquito de palma chilena y se estudia con detalle la composición de su aceite. Con este objetivo, se analizan 4 lotes de coquitos procedentes de las dos regiones de Chile donde existe mayor producción. La composición proximal del coquito indica un contenido muy mayoritario de grasa, con un promedio de 67,3% mientras los contenidos de proteínas, hidratos de carbono y fibra se encuentran entre el 7 y el 11%. Un análisis detallado de la grasa muestra un contenido elevado de ácidos grasos saturados (alrededor del 85%) siendo los ácidos cáprico, caprílico, láurico y mirístico los que se encuentran en mayor concentración, lo que origina un elevado porcentaje de triglicéridos de cadena media. Respecto a los tocoferoles, el aceite contiene cantidades limitadas de α-, γ- y δ-tocoferol con un valor promedio total de 84 mg/kg, no detectándose la presencia de tocotrienoles. Respecto a los fitoesteroles, el contenido total es del orden de 1000 mg/kg siendo los esteroles mayoritarios el β-sitosterol y el Δ7-estigmastenol

    Multifocal papillary carcinoma of the thyroid with heterotopic ossification and extramedullary hematopoiesis associated with a lipomatous follicular nodule

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    Heterotopic ossification has been described in papillary thyroid carcinoma in association with high incidence of extrathyroidal invasion, multifocality, lymph node metastasis, and older age. Nevertheless, it has not been described as a specific subtype of papillary thyroid carcinoma, because of its rarity. We described the case of an 80-year-old female patient, with familial history of papillary thyroid carcinoma. In the annual screening examination, she was diagnosed with thyroid nodules. The patient was submitted to a thyroidectomy because the fine needle aspiration cytology was positive for malignancy according to the Bethesda classification. The surgical specimen analyses showed a multifocal papillary carcinoma with one major lesion in the left lobe measuring 0.9 cm, and two small lesions (0.4 cm and 0.2 cm) in the right lobe. Only the biggest lesion in the right lobe had the osteoid matrix with rare osteoclasts and fat metaplasia with progenitor cells. There was perineural invasion, but vascular invasion was not identified. The margins were free and there was no extrathyroidal extension. In the left lobe there was an oncocytic nodule and a lipomatous follicular nodule. In recent years there has been a significant increase in the diagnosis of thyroid cancer, mainly because of the finding of microcarcinomas as a result of many requests for cervical image exams. Future studies may define (i) whether papillary thyroid carcinoma with heterotopic ossification is a true histological variant; (ii) the causes of that alteration; and (iii) eventual follow-up implications

    Acrilamida en patatas fritas: Revisión actualizada

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    The announcement made by Swedish researches in April 2002 concerning the detection of acrylamide in many different foods, has generated a great deal of scientific publications coming from different parts of the world. The wide spectra of subjects studied includes: the kinetics of the formation and degradation of the acrylamide, the mechanisms proposed for its reduction; the analytical methods and techniques used for its determination and the experimental results obtained either with model systems or by industrial processing in the case of potato crisps and french fries.This review is focused on the state-of-the-art related to the occurrence of acrylamide in foods submitted to heat treatments in industrial operations such as frying, baking, toasting and extrusion. This review also considers the application of potato pre-treatments such as washing, blanching, and immersion in acid solutions. Special emphasis is placed on the differences between atmospheric frying and vacuum frying and on the health risks related to acrylamide intake through common foods.Con posterioridad al anuncio efectuado por investigadores suecos en Abril del año 2002 sobre la detección de acrilamida en un amplio grupo de alimentos, se han originado decenas de trabajos de investigación en diferentes partes del mundo, donde se estudian diversas temáticas de gran importancia, entre las que se pueden mencionar la cinética de la formación y degradación de la acrilamida; los mecanismos propuestos para su reducción; los métodos instrumentales empleados para su determinación y los resultados experimentales generados tanto en modelos experimentales, como en el procesamiento habitual de patatas crisps y french.En este trabajo se revisan los estudios relacionados con la formación de acrilamida en alimentos sometidos a tratamientos térmicos, en operaciones industriales básicas de fritura, horneo, tostado y extrusión. Esta revisión comprende además la aplicación de pretratamientos de lavado previo, escaldado e inmersión en soluciones ácidas de la patata y, finalmente, discute con especial énfasis la diferencia de los resultados obtenidos entre el proceso de fritura de patatas a presión atmosférica y a presión reducida así como la reciente información sobre probables riesgos para la salud humana

    Effect of the COVID-19 pandemic on surgery for indeterminate thyroid nodules (THYCOVID): a retrospective, international, multicentre, cross-sectional study

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    Background Since its outbreak in early 2020, the COVID-19 pandemic has diverted resources from non-urgent and elective procedures, leading to diagnosis and treatment delays, with an increased number of neoplasms at advanced stages worldwide. The aims of this study were to quantify the reduction in surgical activity for indeterminate thyroid nodules during the COVID-19 pandemic; and to evaluate whether delays in surgery led to an increased occurrence of aggressive tumours.Methods In this retrospective, international, cross-sectional study, centres were invited to participate in June 22, 2022; each centre joining the study was asked to provide data from medical records on all surgical thyroidectomies consecutively performed from Jan 1, 2019, to Dec 31, 2021. Patients with indeterminate thyroid nodules were divided into three groups according to when they underwent surgery: from Jan 1, 2019, to Feb 29, 2020 (global prepandemic phase), from March 1, 2020, to May 31, 2021 (pandemic escalation phase), and from June 1 to Dec 31, 2021 (pandemic decrease phase). The main outcomes were, for each phase, the number of surgeries for indeterminate thyroid nodules, and in patients with a postoperative diagnosis of thyroid cancers, the occurrence of tumours larger than 10 mm, extrathyroidal extension, lymph node metastases, vascular invasion, distant metastases, and tumours at high risk of structural disease recurrence. Univariate analysis was used to compare the probability of aggressive thyroid features between the first and third study phases. The study was registered on ClinicalTrials.gov, NCT05178186.Findings Data from 157 centres (n=49 countries) on 87 467 patients who underwent surgery for benign and malignant thyroid disease were collected, of whom 22 974 patients (18 052 [78 center dot 6%] female patients and 4922 [21 center dot 4%] male patients) received surgery for indeterminate thyroid nodules. We observed a significant reduction in surgery for indeterminate thyroid nodules during the pandemic escalation phase (median monthly surgeries per centre, 1 center dot 4 [IQR 0 center dot 6-3 center dot 4]) compared with the prepandemic phase (2 center dot 0 [0 center dot 9-3 center dot 7]; p<0 center dot 0001) and pandemic decrease phase (2 center dot 3 [1 center dot 0-5 center dot 0]; p<0 center dot 0001). Compared with the prepandemic phase, in the pandemic decrease phase we observed an increased occurrence of thyroid tumours larger than 10 mm (2554 [69 center dot 0%] of 3704 vs 1515 [71 center dot 5%] of 2119; OR 1 center dot 1 [95% CI 1 center dot 0-1 center dot 3]; p=0 center dot 042), lymph node metastases (343 [9 center dot 3%] vs 264 [12 center dot 5%]; OR 1 center dot 4 [1 center dot 2-1 center dot 7]; p=0 center dot 0001), and tumours at high risk of structural disease recurrence (203 [5 center dot 7%] of 3584 vs 155 [7 center dot 7%] of 2006; OR 1 center dot 4 [1 center dot 1-1 center dot 7]; p=0 center dot 0039).Interpretation Our study suggests that the reduction in surgical activity for indeterminate thyroid nodules during the COVID-19 pandemic period could have led to an increased occurrence of aggressive thyroid tumours. However, other compelling hypotheses, including increased selection of patients with aggressive malignancies during this period, should be considered. We suggest that surgery for indeterminate thyroid nodules should no longer be postponed even in future instances of pandemic escalation.Funding None.Copyright (c) 2023 Published by Elsevier Ltd. All rights reserved

    Colombian consensus recommendations for diagnosis, management and treatment of the infection by SARS-COV-2/ COVID-19 in health care facilities - Recommendations from expert´s group based and informed on evidence

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    La Asociación Colombiana de Infectología (ACIN) y el Instituto de Evaluación de Nuevas Tecnologías de la Salud (IETS) conformó un grupo de trabajo para desarrollar recomendaciones informadas y basadas en evidencia, por consenso de expertos para la atención, diagnóstico y manejo de casos de Covid 19. Estas guías son dirigidas al personal de salud y buscar dar recomendaciones en los ámbitos de la atención en salud de los casos de Covid-19, en el contexto nacional de Colombia

    Characterization of the seed oil from Chilean palm (Jubaea chllensis) Caracterización del aceite de coquito de palma chilena (Jubaea chilensis)

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    The characteristics of the seeds from Chilean palm and the detailed composition of its fat are studied starting from 4 lots of seeds from the two regions being the major producers of Chilean palm seeds. From the proximate composition of the seeds a high content of fats is deduced with a mean value of 67.3%. The contents of proteins, carbohydrates and fibre were in the range of 7-11%. A detailed analysis of the fat indicates a high content of saturated fatty acids being capric, caprilic, lauric and miristic acids the major fatty acids. For this reason the presence of a high percentage of medium-chain triglycerides are detected in the triglyceride analysis. As for tocopherols, the fat contains low amounts of α-, γ- y δ-tocopherol with a total average of 84 mg/kg. Concerning phytosterols, the total content was around 1000 mg/kg being β-sitosterol and Δ7-estigmastenol the two major sterols

    A macroporous resin purification process to obtain food-grade phlorotannin-rich extracts with α-glucosidase inhibitory activity from Chilean brown seaweeds: An UHPLC-MSn profiling

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    An efficient macroporous resin purification process was designed to obtain food-grade phlorotannin-rich extracts from the seaweeds Durvillaea incurvata and Lessonia spicata. Phlorotannins were profiled to relate structures with the α-glucosidase inhibitory activity of the extracts. Liquid chromatography-mass spectrometry was applied for tentative identification. The best phlorotannin purification performance was achieved with HP-20 resin and elution with 80% v/v ethanol. This is the first study that demonstrates the effectivity of HP-20 resin for removing potentially toxic elements (As, Cd) from seaweed extracts. Fucols/phlorethols/fucophlorethols isomers up to 4 phloroglucinol units (PGU) were the most representative phlorotannins. High molecular weight species (11–21 PGU), although in low abundances, were detected in D. incurvata for the first time. Eckols, carmalols, fuhalols, phenolic acids, and flavonoids were also detected. Some extracts’ potent α-glucosidase inhibitory activities were related to their high phlorotannin abundances, the presence of phlorotannins of a high degree of polymerization, and the phlorotannins class.This research was funded by ANID-Chile through the grant FONDECYT Regular #1180571. It also received financial support from “Programa de Ciencia y Tecnología para el Desarrollo (CYTED), Red Iberoamericana de Alimentos Autóctonos Subutilizados (ALSUBCYTED, #118RT0543)”. F.E. thanks CONICYT Doctoral scholarship (CONICYT-PFCHA/Doctorado Nacional/2017-21170535). The authors appreciate the technical support of Jorge Cantero with the UHPLC-QqTOF-MS2 analysis and the FONDEQUIP EQM170172 project.Peer reviewe

    Chemical evidence of prehistoric passive tobacco consumption by a human perinate (early Formative Period, South-Central Andes)

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    Consumption of psychoactive substances is a long-standing tradition among indigenous peoples of the Americas. Archaeologically, consumption of tobacco has been shown through analysis of archaeological smoking pipe residues, mummy hair and dental calculus. Analysis of the hair of a perinate recovered from a rock shelter in Northern Chile and dated ca. 2400 yrs BP showed the presence of nicotine and its main metabolic product, cotinine. Quantitative segmental hair analysis showed that nicotine was taken up from the mother via the placenta and not through breast milk and that the death of the perinate occurred soon before or at the time of delivery. The analysis also indicated that the mother consumed high quantities of tobacco, suggesting she was a “tobacco shamaness” who might have experienced a miscarriage, since tobacco consumption by pregnant women is strongly associated to spontaneous abortions and perinatal death. Thus, at the dawn of pastoralism and agriculture in the highlands of the Atacama Desert, female individuals were already intensively consuming this psychoactive plant, transmitting its signals, and perhaps its lethal effects, to a child during gestation. This is the first evidence of simultaneous presence of nicotine and cotinine in pre-Hispanic bioanthropological remains from the Americas, thus constituting unequivocal direct evidence of tobacco consumption, and it refers to the currently earliest and youngest passive tobacco consumer in the America

    New sources of oilseeds from Latin American native fruits

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    Three Latin American oilseeds obtained from native fruits: nopal (tuna) (Opuntia ficus-indica), cherimoya (chirimoya) (Annona cherimola), and papaya, Chilean variety (Carica pubescens or C. candamarcensis) were studied for their fatty acid composition and bioactive compounds, such as tocols and phytosterols, looking for new sources of special oilseeds for this region. The results indicated that each species represents an interesting possibility. Nopal oilseed is a good source of linoleic acid (62%), with a good balance between SFA and MUFA (1:1.3). Cherimoya oilseed presents quite a different composition, with 24% SFA, 43% MUFA and 33% PUFA. Palmitic and stearic acids (15% and 7.6%, respectively) are the main SFA. A good balance between oleic acid (42.7%) and linoleic acid (31%) was observed. Papaya oilseed is a highly MUFA oil (72% with 71% oleic acid), with a very interesting composition, according to the new nutritional and technological recommendations. With respect to bioactive c
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