Kidney transplant recipient perspectives on telehealth during the COVID-19 pandemic

The COVID-19 pandemic has challenged the delivery of health services. Telehealth allows delivery of care without in-person contacts and minimizes the risk of vial transmission. We aimed to describe the perspectives of kidney transplant recipients on the benefits, challenges, and risks of telehealth. We conducted five online focus groups with 34 kidney transplant recipients who had experienced a telehealth appointment. Transcripts were thematically analyzed. We identified five themes: minimizing burden (convenient and easy, efficiency of appointments, reducing exposure to risk, limiting work disruptions, and alleviating financial burden); attuning to individual context (depending on stability of health, respect patient choice of care, and ensuring a conducive environment); protecting personal connection and trust (requires established rapport with clinicians, hampering honest conversations, diminished attentiveness without incidental interactions, reassurance of follow-up, and missed opportunity to share lived experience); empowerment and readiness (increased responsibility for self-management, confidence in physical assessment, mental preparedness, and forced independence); navigating technical challenges (interrupted communication, new and daunting technologies, and cognizant of patient digital literacy). Telehealth is convenient and minimizes time, financial, and overall treatment burden. Telehealth should ideally be available after the pandemic, be provided by a trusted nephrologist and supported with resources to help patients prepare for appointments.Brooke M Huuskes, Nicole Scholes-Robertson, Chandana Guha, Amanda Baumgart, Germaine Wong, John Kanellis ... et al

Biochemical Responses of Asparagus to Controlled Atmosphere Storage at 20 Degrees C

In seeking to understand the beneficial effects of controlled atmosphere (CA) storage at 20 degrees C on asparagus (Asparagus officinalis L.), biochemical responses of spear tips stored in air were compared with those of spears stored under CA (2% 02, 10% CO2). CA storage prevented the rapid loss of sucrose, increased acid invertase activity and asparagine accumulation observed in the tips of spears stored in air. CA storage also delayed changes in the levels of glutamine, malic, citric and fumaric acids, compared with those in tips of air-stored spears. Elongation observed in water-fed spears in air was reduced by CA. It is proposed that CA acted by depressing metabolism to such an extent that sucrose levels were maintained in the spear tip and this, in turn, prevented the cascade of metabolic events that contribute to spear deterioration in air

Efficient diterpene production in yeast by engineering Erg20p into a geranylgeranyl diphosphate synthase

Terpenes have numerous applications, ranging from pharmaceuticals to fragrances and biofuels. With increasing interest in producing terpenes sustainably and economically, there has been significant progress in recent years in developing methods for their production in microorganisms. In Saccharomyces cerevisiae, production of the 20-carbon diterpenes has so far proven to be significantly less efficient than production of their 15-carbon sesquiterpene counterparts. In this report, we identify the modular structure of geranylgeranyl diphosphate synthesis in yeast to be a major limitation in diterpene yields, and we engineer the yeast farnesyl diphosphate synthase Erg20p to produce geranylgeranyl diphosphate. Using a combination of protein and genetic engineering, we achieve significant improvements in the production of sclareol and several other isoprenoids, including cis-abienol, abietadiene and β-carotene. We also report the development of yeast strains carrying the engineered Erg20p, which support efficient isoprenoid production and can be used as a dedicated chassis for diterpene production or biosynthetic pathway elucidation. The design developed here can be applied to the production of any GGPP-derived isoprenoid and is compatible with other yeast terpene production platforms. © 2014 International Metabolic Engineering Society

Reconstructing the chemical diversity of labdane-type diterpene biosynthesis in yeast

Terpenes are a large class of natural products, many of which are used in cosmetics, pharmaceuticals, or biofuels. However, terpene[U+05F3]s industrial application is frequently hindered by limited availability of natural sources or low yields of chemical synthesis. In this report, we developed a modular platform based on standardized and exchangeable parts to reproduce and potentially expand the diversity of terpene structures in Saccharomyces cerevisiae. By combining different module-specific parts, we exploited the substrate promiscuity of class I diterpene synthases to produce an array of labdane-type scaffolds. These were subsequently modified by a scaffold decoration module consisting of a mutant library of a promiscuous cytochrome P450 to afford a range of hydroxylated diterpenes. Further P450 protein engineering yielded dedicated and efficient catalysts for specific products. Terpenes produced include precursors of pharmacologically important compounds, molecules that are difficult to obtain from natural sources, or new natural products. The approach described here provides a platform on which additional gene mining, combinatorial biosynthesis, and protein engineering efforts can be integrated to sustainably explore the terpene chemical space. © 2014 International Metabolic Engineering Society

Transcriptome analysis approaches for the isolation of trichome-specific genes from the medicinal plant Cistus creticus subsp. creticus

Cistus creticus subsp. creticus is a plant of intrinsic scientific interest due to the distinctive pharmaceutical properties of its resin. Labdane-type diterpenes, the main constituents of the resin, exhibit considerable antibacterial and cytotoxic activities. In this study chemical analysis of isolated trichomes from different developmental stages revealed that young leaves of 1-2 cm length displayed the highest content of labdane-type diterpenes (80 mg/g fresh weight) whereas trichomes from older leaves (2-3 or 3-4 cm) exhibited gradual decreased concentrations. A cDNA library was constructed enriched in transcripts from trichomes isolated from young leaves, which are characterized by high levels of labdane-type diterpenes. Functional annotation of 2,022 expressed sequence tags (ESTs) from the trichome cDNA library based on homology to A. thaliana genes suggested that 8% of the putative identified sequences were secondary metabolism-related and involved primarily in flavonoid and terpenoid biosynthesis. A significant proportion of the ESTs (38%) displayed no significant similarity to any other DNA deposited in databases, indicating a yet unknown function. Custom DNA microarrays constructed with 1,248 individual clones from the cDNA library facilitated transcriptome comparisons between trichomes and trichome-free tissues. In addition, gene expression studies in various Cistus tissues and organs for one of the genes highlighted as the most differentially expressed by the microarray experiments revealed a putative sesquiterpene synthase with a trichome-specific expression pattern. Full length cDNA isolation and heterologous expression in E. coli followed by biochemical analysis, led to the characterization of the produced protein as germacrene B synthase. © 2008 Springer Science+Business Media B.V

Silencing of ascorbate oxidase results in reduced growth, altered ascorbic acid levels and ripening pattern in melon fruit

Ascorbate oxidase (AO, EC 1.10.3.3) is a copper-containing enzyme localized at the apoplast, where it catalyzes the oxidation of ascorbic acid (AA) to dehydroascorbic acid (DHA) via monodehydroascorbic acid (MDHA) intermediate. Despite it has been extensively studied, no biological roles have been definitively ascribed. To understand the role of AO in plant metabolism, fruit growth and physiology, we suppressed AO expression in melon (Cucumis melo L.) fruit. Reduction of AO activity increased AA content in melon fruit, which is the result of repression of AA oxidation and simultaneous induction of certain biosynthetic and recycling genes. As a consequence, ascorbate redox state was altered in the apoplast. Interestingly, transgenic melon fruit displayed increased ethylene production rate coincided with elevated levels of 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase (ACO, EC 1.14.17.4) activity and gene expression, which might contribute to earlier ripening. Moreover, AO suppressed transgenic melon fruit exhibited a dramatic arrest in fruit growth, due to a simultaneous decrease in fruit cell size and in plasmalemma (PM) ATPase activity. All the above, support for the first time, the in vivo AO participation in the rapid fruit growth of Cucurbitaceae and further suggest an alternative route for AA increase in ripening fruit

Combined metabolome and transcriptome profiling provides new insights into diterpene biosynthesis in S. pomifera glandular trichomes

Background: Salvia diterpenes have been found to have health promoting properties. Among them, carnosic acid and carnosol, tanshinones and sclareol are well known for their cardiovascular, antitumor, antiinflammatory and antioxidant activities. However, many of these compounds are not available at a constant supply and developing biotechnological methods for their production could provide a sustainable alternative. The transcriptome of S.pomifera glandular trichomes was analysed aiming to identify genes that could be used in the engineering of synthetic microbial systems. Results: In the present study, a thorough metabolite analysis of S. pomifera leaves led to the isolation and structure elucidation of carnosic acid-family metabolites including one new natural product. These labdane diterpenes seem to be synthesized through miltiradiene and ferruginol. Transcriptomic analysis of the glandular trichomes from the S. pomifera leaves revealed two genes likely involved in miltiradiene synthesis. Their products were identified and the corresponding enzymes were characterized as copalyl diphosphate synthase (SpCDS) and miltiradiene synthase (SpMilS). In addition, several CYP-encoding transcripts were identified providing a valuable resource for the identification of the biosynthetic mechanism responsible for the production of carnosic acid-family metabolites in S. pomifera. Conclusions: Our work has uncovered the key enzymes involved in miltiradiene biosynthesis in S. pomifera leaf glandular trichomes. The transcriptomic dataset obtained provides a valuable tool for the identification of the CYPs involved in the synthesis of carnosic acid-family metabolites. © 2015 Trikka et al

Biochemical comparison of two grape varieties differing in juice acidity

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