Predictors of Early Mortality After Traumatic Spinal Cord Injury in South Africa.

Study Design: Retrospective cohort study.

Objectives: To identify predictors for early mortality following traumatic spinal cord injury (TSCI), as recognition of factors associated with early mortality is essential for public resource allocation and optimized acute care.

Methods: Retrospective Analysis of SCI patients admitted to the acute SCI ward from 2003 to 2022 was performed.

Civilian ballistic spinal cord injuries versus blunt trauma: comparative analysis of clinical characteristics, management, and outcomes.

Background Context: There are no current guidelines for the management of civilian gunshot wound injuries (GSW) to the spine and patient management often relies on algorithms derived from blunt trauma (BT). However, spinal cord injury due to GSW or blunt trauma mechanism may have significantly different clinical presentation, management, and outcomes. To ensure improved and evidence-based treatment, we need to understand the outcome determining characteristics of civilian GSW to the spine and identify the differences to the well-studied BT.

Does the Level and Complexity of Femur Fracture Determine Intramedullary Peak Pressures During Reamed Femoral Nailing? A Prospective Study.

Objectives: To investigate femoral intramedullary (IM) pressures during reamed antegrade nailing and to determine whether fracture level and/or complexity affect peak pressures.

Design: Prospective, nonrandomized observational cohort.

Setting: Single level I trauma center.

Isotopically non-stationary metabolic flux analysis of heterotrophic cell cultures.

Fluxes are the ultimate phenotype of metabolism and their accurate quantification is fundamental to any understanding of metabolic networks. Steady state metabolic flux analysis has been the method of choice for quantifying fluxes in heterotrophic cells, but it is unable to measure fluxes during short-lived metabolic states, such as a transient oxidative load. Isotopically non-stationary metabolic flux analysis (INST-MFA) can be performed over shorter timescales (minutes - hours) and might overcome this limitation.

Deuterium in marine organic biomarkers: toward a new tool for quantifying aquatic mixotrophy.

The traditional separation between primary producers (autotrophs) and consumers (heterotrophs) at the base of the marine food web is being increasingly replaced by the paradigm that mixoplankton, planktonic protists with the nutritional ability to use both phago(hetero)trophy and photo(auto)trophy to access energy are widespread globally. Thus, many 'phytoplankton' eat, while 50% of 'protozooplankton' also perform photosynthesis. Mixotrophy may enhance primary production, biomass transfer to higher trophic levels and the efficiency of the biological pump to sequester atmospheric CO into the deep ocean.

Metabolic control of nitrogen fixation in rhizobium-legume symbioses.

Rhizobia induce nodule formation on legume roots and differentiate into bacteroids, which catabolize plant-derived dicarboxylates to reduce atmospheric N into ammonia. Despite the agricultural importance of this symbiosis, the mechanisms that govern carbon and nitrogen allocation in bacteroids and promote ammonia secretion to the plant are largely unknown. Using a metabolic model derived from genome-scale datasets, we show that carbon polymer synthesis and alanine secretion by bacteroids facilitate redox balance in microaerobic nodules.

Shining a light on NAD- and NADP-based metabolism in plants.

The pyridine nucleotides nicotinamide adenine dinucleotide [NAD(H)] and nicotinamide adenine dinucleotide phosphate [NADP(H)] simultaneously act as energy transducers, signalling molecules, and redox couples. Recent research into photosynthetic optimisation, photorespiration, immunity, hypoxia/oxygen signalling, development, and post-harvest metabolism have all identified pyridine nucleotides as key metabolites. Further understanding will require accurate description of NAD(P)(H) metabolism, and genetically encoded fluorescent biosensors have recently become available for this purpose.

Topics, Skills, and Cases for an Undergraduate Musculoskeletal Curriculum in Southern Africa: A Consensus from Local and International Experts.

Background: Most patients with orthopaedic pathology in low to middle-income countries are treated by nonspecialists. A curriculum to prepare undergraduate medical students for this duty should reflect the local pathology and skills that are required to manage patients in a resource-restricted environment. The aim of this study was to establish and prioritize a list of core orthopaedic-related knowledge topics, clinical cases, and skills that are relevant to medical students in southern Africa and areas with a similar clinical context.

Limitations of Deuterium-Labelled Substrates for Quantifying NADPH Metabolism in Heterotrophic Cell Cultures.

NADPH is the primary source of cellular reductant for biosynthesis, and strategies for increasing productivity via metabolic engineering need to take account of the requirement for reducing power. In plants, while the oxidative pentose phosphate pathway is the most direct route for NADPH production in heterotrophic tissues, there is increasing evidence that other pathways make significant contributions to redox balance. Deuterium-based isotopic labelling strategies have recently been developed to quantify the relative production of NADPH from different pathways in mammalian cells, but the application of these methods to plants has not been critically evaluated.

Central Metabolic Pathways and Their Subcellular Locations.

Euglenids are a group of algae of great interest for biotechnology, with a large and complex metabolic capability. To study the metabolic network, it is necessary to know where the component enzymes are in the cell, but despite a long history of research into , the subcellular locations of many major pathways are only poorly defined. is phylogenetically distant from other commonly studied algae, they have secondary plastids bounded by three membranes, and they can survive after destruction of their plastids.

Stoichiometric analysis of the energetics and metabolic impact of photorespiration in C3 plants.

Analysis of the impact of photorespiration on plant metabolism is usually based on manual inspection of small network diagrams. Here we create a structural metabolic model that contains the reactions that participate in photorespiration in the plastid, peroxisome, mitochondrion and cytosol, and the metabolite exchanges between them. This model was subjected to elementary flux modes analysis, a technique that enumerates all the component, minimal pathways of a network.

Cell-Type Specific Metabolic Flux Analysis: A Challenge for Metabolic Phenotyping and a Potential Solution in Plants.

Stable isotope labelling experiments are used routinely in metabolic flux analysis (MFA) to determine the metabolic phenotype of cells and tissues. A complication arises in multicellular systems because single cell measurements of transcriptomes, proteomes and metabolomes in multicellular organisms suggest that the metabolic phenotype will differ between cell types. In silico analysis of simulated metabolite isotopomer datasets shows that cellular heterogeneity confounds conventional MFA because labelling data averaged over multiple cell types does not necessarily yield averaged flux values.

Assessing Metabolic Flux in Plants with Radiorespirometry.

Carbohydrates are the dominant respiratory substrate in many plant cells. However, the route of carbohydrate oxidation varies depending on the relative cellular demands for energy, reductant, and precursors for biosynthesis. During these processes individual substrate carbon atoms are differentially released as carbon dioxide by specific reactions in the network, and this can be measured by monitoring the release of CO from a range of positionally labeled forms of [C]glucose.

Lipogenesis and Redox Balance in Nitrogen-Fixing Pea Bacteroids.

Unlabelled: Within legume root nodules, rhizobia differentiate into bacteroids that oxidize host-derived dicarboxylic acids, which is assumed to occur via the tricarboxylic acid (TCA) cycle to generate NAD(P)H for reduction of N2 Metabolic flux analysis of laboratory-grown Rhizobium leguminosarum showed that the flux from [(13)C]succinate was consistent with respiration of an obligate aerobe growing on a TCA cycle intermediate as the sole carbon source. However, the instability of fragile pea bacteroids prevented their steady-state labeling under N2-fixing conditions. Therefore, comparative metabolomic profiling was used to compare free-living R.

Variability in the carbon isotope composition of individual amino acids in plant proteins from different sources: 1 Leaves.

The natural carbon isotope composition of individual amino acids from plant leaf proteins has been measured to establish potential sources of variability. The plant leaves studied, taken from a range of plant groups (forbs, trees, grasses, and freshwater aquatic plants), showed no significant influence of either season or environment (water and light availability) on their Δδ(13)C values. Plant groups did, however, differ in carbon isotope composition, although no consistent differences were identified at the species level.

Process-oriented guided inquiry learning strategy enhances students' higher level thinking skills in a pharmaceutical sciences course.

Objective: To determine if the process-oriented guided inquiry learning (POGIL) teaching strategy improves student performance and engages higher-level thinking skills of first-year pharmacy students in an Introduction to Pharmaceutical Sciences course.

Design: Overall examination scores and scores on questions categorized as requiring either higher-level or lower-level thinking skills were compared in the same course taught over 3 years using traditional lecture methods vs the POGIL strategy. Student perceptions of the latter teaching strategy were also evaluated.

Fluxes through plant metabolic networks: measurements, predictions, insights and challenges.

Although the flows of material through metabolic networks are central to cell function, they are not easy to measure other than at the level of inputs and outputs. This is particularly true in plant cells, where the network spans multiple subcellular compartments and where the network may function either heterotrophically or photoautotrophically. For many years, kinetic modelling of pathways provided the only method for describing the operation of fragments of the network.

Lack of fructose 2,6-bisphosphate compromises photosynthesis and growth in Arabidopsis in fluctuating environments.

The balance between carbon assimilation, storage and utilisation during photosynthesis is dependent on partitioning of photoassimilate between starch and sucrose, and varies in response to changes in the environment. However, the extent to which the capacity to modulate carbon partitioning rapidly through short-term allosteric regulation may contribute to plant performance is unknown. Here we examine the physiological role of fructose 2,6-bisphosphate (Fru-2,6-P2 ) during photosynthesis, growth and reproduction in Arabidopsis thaliana (L.

The metabolic flux phenotype of heterotrophic Arabidopsis cells reveals a flexible balance between the cytosolic and plastidic contributions to carbohydrate oxidation in response to phosphate limitation.

Understanding the mechanisms that allow plants to respond to variable and reduced availability of inorganic phosphate is of increasing agricultural importance because of the continuing depletion of the rock phosphate reserves that are used to combat inadequate phosphate levels in the soil. Changes in gene expression, protein levels, enzyme activities and metabolite levels all point to a reconfiguration of the central metabolic network in response to reduced availability of inorganic phosphate, but the metabolic significance of these changes can only be assessed in terms of the fluxes supported by the network. Steady-state metabolic flux analysis was used to define the metabolic phenotype of a heterotrophic Arabidopsis thaliana cell culture grown on a Murashige and Skoog medium containing 0, 1.

Optimization of steady-state ¹³C-labeling experiments for metabolic flux analysis.

While steady-state (13)C metabolic flux analysis is a powerful method for deducing multiple fluxes in the central metabolic network of heterotrophic and mixotrophic plant tissues, it is also time-consuming and technically challenging. Key steps in the design and interpretation of steady-state (13)C labeling experiments are illustrated with a generic protocol based on applications to plant cell suspension cultures.

The metabolic flux phenotype of heterotrophic Arabidopsis cells reveals a complex response to changes in nitrogen supply.

The extent to which individual plants utilise nitrate and ammonium, the two principal nitrogen sources in the rhizosphere, is variable and many species require a balance between the two forms for optimal growth. The effects of nitrate and ammonium on gene expression, enzyme activity and metabolite composition have been documented extensively with the aim of understanding the way in which plant cells respond to the different forms of nitrogen, but ultimately the impact of these changes on the organisation and operation of the central metabolic network can only be addressed by analysing the fluxes supported by the network. Accordingly steady-state metabolic flux analysis was used to define the metabolic phenotype of a heterotrophic Arabidopsis thaliana cell culture grown in Murashige and Skoog and ammonium-free media, treatments that influenced growth and biomass composition.

Metabolic engineering of tomato fruit organic acid content guided by biochemical analysis of an introgression line.

Organic acid content is regarded as one of the most important quality traits of fresh tomato (Solanum lycopersicum). However, the complexity of carboxylic acid metabolism and storage means that it is difficult to predict the best way to engineer altered carboxylic acid levels. Here, we used a biochemical analysis of a tomato introgression line with increased levels of fruit citrate and malate at breaker stage to identify a metabolic engineering target that was subsequently tested in transgenic plants.