19 research outputs found
Roger Llewellyn Dunmore Cribb Obituary (1948 - 2007)
This publication does not have an abstract. The first two paragraphs of this article are displayed as the abstract.
Many people knew Roger Cribb, or we thought we did. Since he died on Sunday 26 August 2007 in Cairns, north Queensland, a variety of people have written about the Roger they knew (for example, the obituaries by his ex-wife and friend Gulcin Cribb (2007) and the Wikipedia page put
together by Bruce White (2007)). The questions many of us now ask ourselves are 'How many Rogers were there?' and 'Where did the Roger we know fit in?'
I was asked to write this obituary and I was happy to do so as I admired Roger's tenacity and his genuine concern for Aboriginal peoples in Cape York. However, I felt inadequate for the task on my own and so sought input from two other
north Queenslanders who knew him well, Bruce White and George Skeene. Bruce worked with Roger at Tharpuntoo Legal Service and George is a Yirrganydji Traditional Owner with whom Roger worked on a voluntary basis over many years, helping him to map and record the archaeological sites of his people
One filter, one sample and the N- and O-glyco(proteo)me: towards a system to study disorders of protein glycosylation. : Toward a System to Study Disorders of Protein Glycosylation
A method has been developed for release/isolation of O-glycans from glycoproteins in whole cell lysates for mass spectrometric analysis. Cells are lysed in SDS, which is then exchanged for urea and ammonium bicarbonate in a centrifugal filter, before treating with NH4OH to release O-glycans. Following centrifugation, O-glycans are recovered in the filtrate. Sonication achieves O-glycan release in 1 h. Combining the established protocol for filter-aided N-glycan separation, here optimized for enhanced PNGase F efficiency, with the developed O-glycan release method allows analysis of both N- and O-glycans from one sample, in the same filter unit, from 0.5 to 1 million cells. The method is compatible with subsequent analysis of the residual protein by liquid chromatography-mass spectrometry (LC-MS) after glycan release. The medium throughput approach is amenable to analysis of biological replicates, offering a simple way to assess the often subtle changes to glycan profiles accompanying differentiation and disease progression, in a statistically robust way
Modeling Glycan Processing Reveals Golgi-Enzyme Homeostasis upon Trafficking Defects and Cellular Differentiation
The decoration of proteins by carbohydrates is essential for eukaryotic life yet heterogeneous due to a lack of biosynthetic templates. This complex carbohydrate mixture-the glycan profile-is generated in the compartmentalized Golgi, in which level and localization of glycosylation enzymes are key determinants. Here, we develop and validate a computational model for glycan biosynthesis to probe how the biosynthetic machinery creates different glycan profiles. We combined stochastic modeling with Bayesian fitting that enables rigorous comparison to experimental data despite starting with uncertain initial parameters. This is an important development in the field of glycan modeling, which revealed biological insights about the glycosylation machinery in altered cellular states. We experimentally validated changes in N-linked glycan-modifying enzymes in cells with perturbed intra-Golgi-enzyme sorting and the predicted glycan-branching activity during osteogenesis. Our model can provide detailed information on altered biosynthetic paths, with potential for advancing treatments for glycosylation-related diseases and glyco-engineering of cells
One sample, one pot and the whole glycome: towards a system to study disorders of protein glycosylation
Glycoprotein glycosylation is altered in many diseases, including congenital disorders of glycosylation, as well as in cell differentiation. Alterations to the presence and location of glycan biosynthetic enzymes can manifest in subtle changes to glycan profiles. To determine which of these changes are statistically significant, analysis of multiple biological samples in parallel is needed. Protein glycosylation is also a major consideration in the pharmaceutical industry, with an increase in engineering of glycoprotein-based therapeutics. In therapeutic protein development, glycan structures can influence efficacy and stability. It is therefore important to understand glycan biosynthesis and to have a convenient means to assess the structures of glycans in order to further understand disease and genetic disorders linked to errors in glycosylation, as well as to potentially contribute to disease diagnostics and to inform development of biotherapeutics.
A filter-aid N-glycan separation (FANGS) method was recently developed, to release and isolate N-glycans, from a small number of culture whole cell lysates, for mass spectrometric analysis. This thesis presents a FANGS-based approach, to carry out O-glycan release, using β-elimination. Through method optimisation, O-glycan release can be achieved with 20 minutes of sonication, and gives comparable results to those from well-accepted overnight incubation methods. In addition, the thesis presents a streamlined protocol for a one-sample-one-pot approach to release N- and O-glycans from the same sample, in the same pot, with the potential to subsequently analyse protein remaining in the filter. Analysing both N- and O-glycans from one sample is important since in disease it is not always only one type of glycosylation that is altered. The developed method has been applied to mesenchymal stromal cells (MSCs), before and after differentiation into adipocytes, as well as genetically manipulated MSCs, in addition to undifferentiated and differentiated normal human urothelial cells. In both cell systems, changes could be observed in both the N- and O-glycan profiles. The approach offers insight into potential functional role of glycans in cellular processes such as differentiation and disease
Innovation toward the reinvigoration of the plant extracts industry in Trinidad and Tobago
Extraction curves at 45oC
References for MDPI Journal articl
Comparison of the Sub-Critical Fluid Extraction of the Essential Oil of Turmeric (Curcuma longa L.) with That of Hydrodistillation
Turmeric (Curcuma longa L.) is a spice plant grown in the tropics that contains both an essential oil and an oleoresin. The essential oil is important as a flavouring and has pharmaceutical properties, while the oleoresin is bright yellow in colour and has medicinal properties. The essential oil has traditionally been extracted by hydrodistillation/steam distillation with the total extract being extracted by solvent extraction and more recently by supercritical fluid extraction (SFE). The objective of the work described in this paper was to investigate the possibility of extracting the essential oil using sub-critical fluid extraction and to compare it with hydrodistillation. The experiments using hydrodistillation showed that unpeeled fresh turmeric was the preferred raw material, giving an oil yield of ≈6% dry weight basis, which is similar to that reported in the literature. The experimental programme on the extraction of the oil from dried unpeeled turmeric was carried out over a temperature range from 25 to 30 °C and pressures from 65 to 71 bar. Yields were generally higher than hydrodistillation (up to ≈9% dry weight basis) as were the compositions of the extracted oils. The preferred operating conditions were determined to be 25 °C temperature and 65 bar pressure. Curcumin, the major component of the oleoresin, was not found in the oil, thereby demonstrating that the sub-critical extract is a pure essential oil. It is suggested that consideration be given to evaluating an SFE process whereby the essential oil is initially fully extracted under sub-critical fluid extraction conditions, after which the oleoresin is extracted separately by raising the pressure to ≈250 bar
Innovation toward the reinvigoration of the plant extracts industry in Trinidad and Tobago
Extraction curves at 45oC
References for MDPI Journal articl
Comparison of the Sub-Critical Fluid Extraction of the Essential Oil of Turmeric (<i>Curcuma longa</i> L.) with That of Hydrodistillation
Turmeric (Curcuma longa L.) is a spice plant grown in the tropics that contains both an essential oil and an oleoresin. The essential oil is important as a flavouring and has pharmaceutical properties, while the oleoresin is bright yellow in colour and has medicinal properties. The essential oil has traditionally been extracted by hydrodistillation/steam distillation with the total extract being extracted by solvent extraction and more recently by supercritical fluid extraction (SFE). The objective of the work described in this paper was to investigate the possibility of extracting the essential oil using sub-critical fluid extraction and to compare it with hydrodistillation. The experiments using hydrodistillation showed that unpeeled fresh turmeric was the preferred raw material, giving an oil yield of ≈6% dry weight basis, which is similar to that reported in the literature. The experimental programme on the extraction of the oil from dried unpeeled turmeric was carried out over a temperature range from 25 to 30 °C and pressures from 65 to 71 bar. Yields were generally higher than hydrodistillation (up to ≈9% dry weight basis) as were the compositions of the extracted oils. The preferred operating conditions were determined to be 25 °C temperature and 65 bar pressure. Curcumin, the major component of the oleoresin, was not found in the oil, thereby demonstrating that the sub-critical extract is a pure essential oil. It is suggested that consideration be given to evaluating an SFE process whereby the essential oil is initially fully extracted under sub-critical fluid extraction conditions, after which the oleoresin is extracted separately by raising the pressure to ≈250 bar
Data for Journal article on Sub critical /Hydrodistillation comparison
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